Researcher Profile and Settings

Affiliation

• Faculty of Dental Medicine　Division of Dental Medicine　Department of Health Science

Job Title

• Associate Professor

Degree

• DDS（Bauru School of Dentistry, University of Sao Paulo）
• MS（Bauru School of Dentistry, University of Sao Paulo）
• PhD（Tokyo Medical and Dental University）

Contact information

• myamautiden.hokudai.ac.jp

J-Global ID

• 201801012823137911

Profile

• I am Monica Yamauti from Brazil. I have graduated from Bauru School of Dentistry at University of Sao Paulo (Brazil, 1994), where I also got the Master Degree (1999). I got the PhD degree from Tokyo Medical and Dental University (Japan, 2005).
  
  The main research interests are: Cariology, Dental Materials (adhesive materials and ceramics), Dental Substrates

Research Interests

• Physical, chemical and biological properties of matter   Bonding to enamel and dentin   Enamel   Dental Developmental Defects   Dentin   Adhesion   Dental Materials   Cariology   

Research Areas

• Life sciences / Conservative dentistry and endodontics / Operative and Restorative Dentistry, Dental Materials

Educational Organization

•  Bachelor's degree program　School of Dental Medicine
•  Doctoral (PhD) degree program　Graduate school of Dental Medicine

Academic & Professional Experience

• 1997/02 - 1999/06 Bauru School of Dentistry, University of Sao Paulo Operative Dentistry
• 1995/01 - 1996/12 Bauru School of Dentistry, Univeristy of Sao Paulo Operative Dentistry Intern

Education

• 2001/04 - 2005/03  Tokyo Medical and Dental University  Cariology and Operative Dentistry  Doctoral
• 1997/02 - 1999/06  Bauru School of Dentistry, University of Sao Paulo  Endodontics, Operative Dentistry and Dental Materials  Master in Operative Dentistry and Dental Materials
• 1996/02 - 1997/04  Instituto de Estudos Odontologicos  CE in Periodontics and Prosthodontics
• 1995/03 - 1995/12  Instituto de Estudos Odontologicos  CE in Periodontics
• 1991/02 - 1994/12  Bauru School of Dentistry, University of Sao Paulo  Bachelor in Dentistry

Association Memberships

• THE D3 GROUP FOR DEVELOPMENTAL DENTAL DEFECTS   Japanese Society for Adhesive Dentistry   International Academy of Adhesive Dentistry   ORCA   Japanese Division of IADR   Japanese Society for Conservative Dentistry   Academy of Dental Materials   International Association for Dental Research   Brazilian Division of IADR   

Research Activities

Published Papers

• Effects of Short-Term Exposure of Chloramine-T Solution on the Characteristics of Light-Cured and Chemical-Cured Adhesives

  Yunqing Liu, Norihito Sakaguchi, Masahiro Iijima, Md Refat Readul Islam, Jiayuan Zhang, Rafiqul Islam, Monica Yamauti, Hidehiko Sano, Atsushi Tomokiyo

  Polymers 15 (19) 3995 - 3995 2023/10/05 

  This study evaluated the effect of a 0.5% chloramine T solution on a chemical-cured universal adhesive by comparing the light-cured, one-step, self-etch adhesive for the bonding performance, mechanical properties, and resin–dentin interfacial characteristics. Caries-free human molars were randomly assigned into eight groups based on the bonding systems employed (Bond Force II, BF and Bondmer Lightless, BL), the immersion solutions used before bonding (0.5% chloramine T solution and distilled water), and the immersion durations (5 and 60 min). Microtensile bond strength (μTBS), nanoleakage evaluation, and nanoindentation tests were performed, and the surface morphology of the resin–dentin interface was examined using a focus ion beam/scanning ion microscopy system. Immersion in chloramine-T for 5 min significantly decreased the μTBS of Bondmer Lightless (from 22.62 to 12.87 MPa) compared with that in distilled water. Moreover, there was also a decreasing trend after immersing in chloramine-T for 60 min (from 19.11 to 13.93 MPa). Chloramine T was found to have no effect on the hardness, elastic modulus, or morphological characteristics of the ion-beam milled resin–dentin interfacial surfaces in the tested adhesives, suggesting that chloramine T might reduce the bond strength by interfering with the interaction and the sealing between the adhesive resin and dentin in the chemical-cured universal adhesive, albeit without affecting the mechanical properties.
• Hydroxyapatite Affects the Physicochemical Properties of Contemporary One-Step Self-Etch Adhesives.

  Yutaro Motoyama, Monica Yamauti, Masatoshi Nakajima, Masaomi Ikeda, Junji Tagami, Yasushi Shimada, Keiichi Hosaka

  Materials (Basel, Switzerland) 15 (22) 2022/11/21 

  The study aimed to evaluate the influence of the manipulation surfaces on the physical properties of one-step self-etch adhesives (1-SEAs). Scotchbond Universal (SBU), Clearfil Universal Bond Quick ER (UBQ), and an experimental adhesive (UBQexp) were manipulated on different surfaces: manufacturer's Teflon-based dispensing dish (TD) or hydroxyapatite plate (HA). After manipulation of the adhesives, the pH of each 1-SEA was measured. Samples of each adhesive/manipulation surface were prepared and subjected to water sorption (WS)/solubility (SL) and flexural strength tests. The modulus of elasticity (E) was measured in dry and wet conditions before and after 24 h water storage, and the percentage of variation of E (ΔE) was calculated. Results were analyzed using the t-test with Bonferroni corrections (α = 0.05). When adhesives were manipulated on the HA plate, there was a significant increase in the adhesives' pH. WS and SL of all 1-SEAs decreased when the HA was used. Only SBU showed higher flexural strength when manipulated on the HA compared to the manipulation on TD under dry and wet conditions. For each 1-SEA, the use of HA resulted in significantly higher E in dry and wet conditions. ΔE of all adhesives was smaller with the manipulation on HA than on TD. It was concluded that the manipulation of 1-SEA on a hydroxyapatite plate considerably affected the adhesives' properties.
• Enhanced mechanical properties, anti-biofilm activity, and cytocompatibility of a methacrylate-based polymer loaded with native multiwalled carbon nanotubes.

  Ricardo Antonio Alpino Rodrigues, Rosangela Maria Ferreira da Costa E Silva, Luiza de Almeida Queiroz Ferreira, Natália Tavares Teixeira Branco, Érick de Souza Ávila, Anderson Maia Peres, Weslley Fernandes-Braga, Augusto César Sette-Dias, Ângela Leão Andrade, Regina Guenka Palma-Dibb, Cláudia Silami de Magalhães, Luiz Orlando Ladeira, Rodrigo Richard da Silveira, Allyson Nogueira Moreira, Paulo Antônio Martins Júnior, Mônica Yamauti, Ivana Márcia Alves Diniz

  Journal of the mechanical behavior of biomedical materials 136 105511 - 105511 2022/10/11 

  OBJECTIVES: We aimed to optimize the mechanical and biological properties of a conventional methacrylate-based dental polymer by loading it with double- and triple-walled carbon nanotubes as growth (DTWCNTG). METHODS: A formulation of bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate (mass ratio = 2:1) was mixed with DTWCNTG at concentrations of 0.0% (control), 0.001%, 0.005%, and 0.010%. The concentrations were physicochemical and morphologically evaluated, and antibacterial activity was assessed by seeding a Streptococcus mutans strain (ATCC 25175) on the experimental polymeric surfaces. Cellular survival and osteodifferentiation were evaluated in epithelial (HaCat) and preosteoblast cells (MC3T3-E1). RESULTS: The 0.001% DTWCNTG concentration yielded higher compressive strength, elastic modulus, flexural strength, flexural modulus, water sorption, and solubility than the control. The degree of conversion and color did not significantly change with a low amount of DTWCNTG incorporated into the polymer. Antibacterial activity significantly improved when tested on the 0.001% DTWCNTG discs. No groups showed cytotoxicity in a short-term analysis and adding DTWCNTG favored MC3T3-E1 mineralization over the control, particularly in the 0.001% formulation. SIGNIFICANCE: The micro-addition of 0.001% DTWCNTG confers mechanical resistance, antimicrobial properties, and bioactivity to methacrylate-based polymers without significantly compromising color. Incorporating DTWCNTG improved dental composite properties and could be a biomodified material for minimally invasive procedures.
• Teledentistry as an Effective Tool for the Communication Improvement between Dentists and Patients: An Overview.

  Md Refat Readul Islam, Rafiqul Islam, Sultana Ferdous, Chiharu Watanabe, Monica Yamauti, Mohammad Khursheed Alam, Hidehiko Sano

  Healthcare (Basel, Switzerland) 10 (8) 2022/08/21 

  Teledentistry is an online dental care service that allows patients and dentists to meet in real time, safely, without being at the same location. During the COVID-19 pandemic, real-time videoconferencing has gained popularity in the field of teledentistry, with numerous benefits for both patients and dentists. Online consultations can minimize costs, maximize time, and provide more convenient care options for both patients and dentists. When practicing teledentistry, a dentist must establish a good doctor-patient relationship. Dentists must ensure that the telecommunication solution that they choose meets their clinical requirements and complies with privacy laws. Dentists should provide adequate information to patients about the limitations, advantages, and disadvantages that may occur during online consultation. Dentists must follow guidelines and procedures regarding informed consent, patient details, personal communications, and consultancies' privacy and confidentiality. The patient should be aware of the limitations of teledentistry, and dentists will provide the best advice possible in the absence of a face-to-face consultation. This article discusses how teledentistry could be an effective tool for dentists and patients.
• Cause-Effect Relationship of Varying Bonding Thicknesses in Dentin Adhesion of Universal Adhesives.

  Arefin Alam, Abu Faem Mohammad Almas Chowdhury, Monica Yamauti, Pipop Saikaew, Shuhei Hoshika, Ricardo Marins Carvalho, Hidehiko Sano, Sharanbir K Sidhu

  The journal of adhesive dentistry 24 (1) 291 - 300 2022/08/18 

  PURPOSE: To evaluate whether varying thicknesses of universal adhesives utilizing the additional coating strategy would affect their microtensile bond strength (µTBS) to dentin, hardness, and elastic modulus (mechanical properties). MATERIALS AND METHODS: Ninety-nine human maxillary premolars were cut to expose coronal dentin, ground with regular-grit diamond burs, and randomly distributed into 9 groups based on 1. adhesive: Scotchbond Universal Adhesive (SB; universal), G Premio Bond (GP; universal) and Clearfil Megabond 2 (MB; two-step self-etch; control); and 2. application strategy (one, two or three coats; each coat light cured). After adhesive application and resin composite buildup, the bonded teeth were stored in distilled water (37°C; 24 h). Resin-dentin sticks from eight premolars per group (each premolar yielded 3 sticks; n = 24 sticks altogether) were prepared for the µTBS test, followed by measurement of the adhesive thicknesses at their fractured ends using SEM. The mechanical properties of the adhesive layers produced by different coats were evaluated on separate resin-dentin slices (n = 3 teeth per group). RESULTS: Two coats significantly increased the µTBS (p < 0.001) of all the adhesives. The correlation between adhesive thickness and bond strength was positive for GP but negative for SB. MB did not show any correlation. Additional coating significantly increased the mechanical properties of GP (p < 0.05) but did not affect SB and MB (p < 0.05). CONCLUSION: An additional adhesive coating over the manufacturers' recommendations improved the bond strength of all the adhesives tested. However, the increased mechanical properties of the adhesives with additional curing was material dependent.
• Evaluation of the clinical performance of GIOMERs and comparison with other conventional restorative materials in permanent teeth: a systematic review and meta-analysis.

  Clóvis Ciryllo Limonge Neto, André Martins das Neves, Diandra Costa Arantes, Tassiana Cançado Melo Sa, Monica Yamauti, Cláudia Silami de Magalhães, Lucas Guimarães Abreu, Allyson Nogueira Moreira

  Evidence-based dentistry 2022/08/01 

  Aim The aim of this systematic review and meta-analysis was to analyse the clinical performance of GIOMER restorative composites and compare them with other conventional restorative materials in permanent teeth.Methods Searches in PubMed, Web of Science, Scopus, Ovid and Cochrane Library were conducted. Grey literature search was also performed. Clinical trials that evaluated the clinical performance of restorations with GIOMER restorative composites in permanent teeth compared to those using composite resin, glass ionomer cement, resin-modified glass ionomer cement (RMGIC) and other GIOMERs were included. Meta-analyses comparing GIOMER restorative composites with RMGIC at 6- and 12-month follow-ups and comparing two types of GIOMER were feasible.Results Ten studies fulfilled the inclusion criteria. In these studies, GIOMER was compared to different types of dental restoration materials. Dental restorations were evaluated by United States Public Health Service criteria in all included studies. Four studies were suitable for meta-analysis, which showed significant differences between GIOMER and RMGIC surface roughness at 6-month (odds ratio [OR] = 6.56; 95% confidence interval [CI] = 2.38-18.13) and 12-month (OR = 8.76; CI = 3.19-24.07) follow-ups. No significant differences between GIOMER restorative composites and RMGIC for marginal adaptation were found at 6- and 12-month follow-ups. When comparing two GIOMERs, significant differences were seen between Beautifil II and Beautifil Flowable Plus F00 for marginal staining (OR = 2.58; CI = 1.42-23.27; I2 = 0%) and surface roughness (OR = 4.59; CI = 1.11-18.97; I2 = 0%) at the 36-month follow-up. No significant differences between Beautifil II and Beautifil Flowable Plus F00 were seen for marginal adaptation and anatomic form at 6-, 18- and 36-month follow-ups.Conclusions GIOMER restorative composites presented similar performance concerning marginal adaptation and better surface roughness when compared to RMGIC. GIOMER Beautifil II presented similar performance to GIOMER Beautifil Flow Plus F00 concerning marginal adaptation and anatomic form and worse marginal staining and surface roughness when compared to Beautifil Flowable Plus F00.
• Evaluation of Color and Spectral Behavior of a Novel Flowable Resin Composite after Water Aging: An In Vitro Study.

  Fei Chen, Di Wu, Rafiqul Islam, Yu Toida, Chiharu Kawamoto, Monica Yamauti, Hidehiko Sano

  Materials (Basel, Switzerland) 15 (12) 2022/06/09 

  BACKGROUND: This study aimed to evaluate the color matching, light transmittance, and reflectance characteristics of the novel flowable resin composite OCF-001 (OCF). METHODS: Fifty-four resin composite molds were made with simulated class I cavities of A2, A3, and A4 shades by filling the rubber mold interspace with Estelite Sigma Quick (ESQ), Gracefil Putty (GP) and Filtek Supremme Ultra (FSU). After applying the adhesive, three different flowable resin composites (n = 6), OCF, Gracefil LoFlo (GLF), and Supreme Ultra Flowable (SUF), were used to fill the cavities. A colorimeter was used to measure the color parameters (CIEDE2000). The color measurements were taken immediately and after 28 days. Data were analyzed using the nonparametric Kruskal-Wallis (α = 0.05) and Wilcoxon tests. The light transmittance and reflection characteristics were measured with a black background using a spectrophotometer under D65 illumination. RESULTS: The ΔE00, and ΔC of OCF was lower than other tested materials in A2 and A3 shades both immediately and after 28 days. OCF showed the highest transmittance characteristic, and a relatively stable reflectance curve in all the wavelengths. CONCLUSIONS: OCF showed better shade matching with the surrounding shades of A2 and A3, a relative uniform reflectance and higher light transmission properties.
• Antibacterial potential of colloidal platinum nanoparticles against Streptococcus mutans.

  Hongbo Zhang, Akira Hasebe, Arefin Alam, Yunqing Liu, Shuhei Hoshika, Monica Yamauti, Hidehiko Sano

  Dental materials journal 41 (3) 368 - 375 2022/05/31 

  This study evaluated the antibacterial activity of colloidal platinum nanoparticles (CPNs) toward Streptococcus mutans (S. mutans) viability. S. mutans 109c was treated with water and three CPN solutions at 37°C for 24 h (i.e., control, PAA-Pt, C-Pt, C-CyD-Pt). Dilution series (10-1-10-5) were prepared using brain heart infusion (BHI) broth for all samples, and a 100 µL suspension of each dilution was spread onto a BHI agar plate. Colony-forming units (CFU/mL) were determined after 24 h. The effects of CPNs on S. mutans survival and biofilm formation were investigated using fluorescence and scanning electron microscopies. The antibacterial rate of S. mutans increased with increasing concentrations of all three CPNs, with PAA-Pt nanoparticles exhibiting the highest antibacterial efficacy. CPNs were found to reduce S. mutans growth and inhibit biofilm formation remarkably.
• Microtensile Bond Strength Testing

  Hidehiko SANO, Mariko MATSUMOTO, Shuhei HOSHIKA, Monica YAMAUTI

  The Japanese Journal of Conservative Dentistry 特定非営利活動法人 日本歯科保存学会 65 (1) 1 - 8 0387-2343 2022/02/28
• 新規微小引張試験法開発への予備的検討

  山下 航司, 戸井田 侑, 川村 碧, 川野 晋平, 松本 真理子, 星加 修平, 川本 千春, 池田 考績, 田中 享, モニカ・ヤマウチ, 佐野 英彦

  特定非営利活動法人日本歯科保存学会学術大会プログラムおよび講演抄録集 (NPO)日本歯科保存学会 155回 63 - 63 2021/10
• Characterization of an Experimental Two-Step Self-Etch Adhesive's Bonding Performance and Resin-Dentin Interfacial Properties.

  Abu Faem Mohammad Almas Chowdhury, Arefin Alam, Monica Yamauti, Pedro Álvarez Lloret, Pipop Saikaew, Ricardo Marins Carvalho, Hidehiko Sano

  Polymers 13 (7) 2021/03/25 

  This study evaluated an experimental two-step self-etch adhesive (BZF-29, BZF) by comparing it with a reference two-step self-etch adhesive (Clearfil Megabond 2, MB) and a universal adhesive (G-Premio Bond, GP) for microtensile bond strength (μTBS) and resin-dentin interfacial characteristics. Twenty-four human third molars were used for the μTBS test. Bonded peripheral dentin slices were separated to observe the resin-dentin interface and measure the adhesive layer thickness with SEM. μTBS data of the central beams were obtained after 24 h and 6 months of water storage. Fracture modes were determined using a stereomicroscope and SEM. Nine additional third molars were used to determine the elastic modulus (E) employing an ultra microhardness tester. Water storage did not affect μTBS of the tested adhesives (p > 0.05). μTBS of BZF and MB were similar but significantly higher than GP (p < 0.05). BZF achieved the highest adhesive layer thickness, while GP the lowest. E of BZF and MB were comparable but significantly lower than GP (p < 0.05). Except for GP, the predominant fracture mode was nonadhesive. The superior bonding performance of BZF and MB could be attributed to their better mechanical property and increased adhesive thickness imparting better stress relief at the interface.
• The Influences of Dehydration on the Mechanical Properties of Human Dentin

  Abu Faem Mohammad Almas Chowdhury, Arefin Alam, MD Refat Readul Islam, Monica Yamauti, Mohammad Shafiqul Alam, Mohammad Musfiqur Rahman, Asad-Uz-Zaman, Mohiuddin Ahmed, Pedro Álvarez-Lloret, Hidehiko Sano

  Minerals 11 (4) 336 - 336 2021/03/24 

  The complex, dynamic, and hydrated microstructures of human dentin serve as the major determinant for the restorative performance of biomaterials. This study aimed to evaluate the mechanical properties of human dentin under different hydration conditions. The occlusal dentin of five third molars was exposed and cut into 1 mm2 dentin slabs. The slabs were then polished and further cut into 1 mm2 dentin beams and stored in distilled water. Two beams/tooth were used for testing their hardness (H) and elastic modulus (E) at 5 min (baseline), 1 h, and 24 h after dehydration (23 °C and 30% RH), and also for measuring weight at following dehydration times: 0 min, 5 min, 1 h, and 24 h. Five additional molars were employed to prepare 0.4 mm2 dentin beams (3/tooth) for determining ultimate tensile strength (UTS) at 5 min (baseline), 1 h, and 24 h post-dehydration. Statistical significance was set at α = 0.05. Dehydration time significantly affected H, E, weight-loss, and UTS of dentin (p < 0.05). H and E values showed a strongly positive and significant correlation (r > 0.5, p < 0.05). Dehydration can substantially modify the mechanical properties of dentin, leading to misinterpretation of restorative outcomes in vitro.
• UV-Mediated Photofunctionalization of Indirect Restorative Materials Enhances Bonding to a Resin-Based Luting Agent.

  Kyoko Ishikawa, Monica Yamauti, Antonin Tichy, Masaomi Ikeda, Takeshi Ueno, Noriyuki Wakabayashi, Ornnicha Thanatvarakorn, Taweesak Prasansuttiporn, Celso Afonso Klein-Junior, Akifumi Takahashi, Tomohiro Takagaki, Masatoshi Nakajima, Junji Tagami, Keiichi Hosaka

  BioMed research international 2021 9987860 - 9987860 2021 

  Purpose: The potential of UV-mediated photofunctionalization to enhance the resin-based luting agent bonding performance to aged materials was investigated. Methods: Sixty samples of each material were prepared. Yttria-stabilized zirconia (YZr) and Pd-Au alloy (Pd-Au) plates were fabricated and sandblasted. Lithium disilicate glass-ceramic (LDS) was CAD-CAM prepared and ground with #800 SiC paper. Half of the specimens were immersed in machine oil for 24 h to simulate the carbon adsorption. Then, all of the specimens (noncarbon- and carbon-adsorbed) were submitted to UV-mediated photofunctionalization with a 15 W UV-LED (265 nm, 300 mA, 7692 μW/cm2) for 0 (control groups), 5, and 15 min and subjected to contact angle (Ɵ) measurement and bonded using a resin cement (Panavia™ V5, Kuraray Noritake, Japan). The tensile bond strength (TBS) test was performed after 24 h. The Ɵ (°) and TBS (MPa) data were statistically analyzed using two-way ANOVA and Bonferroni correction tests (α = 0.05). Results: In the carbon-adsorbed groups, UV-mediated photofunctionalization for 5 min significantly decreased Ɵ of all materials and increased TBS of YZr, and UV for 15 min significantly increased the TBS of LDS and Pd-Au. In noncarbon-adsorbed groups, UV-photofunctionalization did not significantly change the Ɵ or TBS except YZr specimens UV-photofunctionalized for 15 min. Conclusion: UV-mediated photofunctionalization might have removed the adsorbed hydrocarbon molecules from the materials' surfaces and enhanced bond strengths of Panavia™ V5 to YZr, LDS, and Pd-Au. Additionally, UV-mediated photofunctionalization improved the overall TBS of YZr. Further investigation on the optimum conditions of UV photofunctionalization on indirect restorative materials should be conducted.
• Effects of remaining dentin thickness, smear layer and aging on the bond strengths of self-etch adhesives to dentin.

  Rime Shamme Akter, Zubaer Ahmed, Monica Yamauti, Ricardo M Carvalho, Abu Faem Mohammad Almas Chowdhury, Hidehiko Sano

  Dental materials journal 2020/12/17 

  This study evaluated the effects of remaining dentin thickness (RDT), different smear layers, and aging on the microtensile bond strength (µTBS) of universal adhesives to dentin when applied in self-etch mode. Ninety-six human third molars were randomly allocated to 12 groups (n=8) based on adhesives: ClearfilTM SE Bond 2 (SE, control), ClearfilTM Universal Bond (CU) and ScotchBondTM Universal Adhesive (SB); smear layers: prepared either with 600-grit SiC paper (P) or regular diamond bur (B); and aging: stored in distilled water at 37ºC for 24 hours (24h) or 1 year (1y). µTBS was significantly affected by the type of adhesives, smear layers, and aging (p<0.001). A statistically significant and positive linear relationship was also observed between µTBS and RDT (p<0.05) in all the tested groups, except for SEB1y and CUB24h (p>0.05). RDT, smear layer types, and aging can influence the bonding performances of universal adhesives when applied in self-etch mode.
• The microtensile bond strength test: Its historical background and application to bond testing.

  Hidehiko Sano, Abu Faem Mohammad Almas Chowdhury, Pipop Saikaew, Mariko Matsumoto, Shuhei Hoshika, Monica Yamauti

  The Japanese dental science review 56 (1) 24 - 31 2020/12 [Refereed][Not invited]
   

  Microtensile bond strength (μTBS) test was introduced in 1994. Since then, it has been utilized profoundly across many bond strength testing laboratories, making it currently one of the most standard and versatile bond strength test. Although it is a static and strength-based method, together with the morphological and spectroscopic investigations, it has been contributing immensely in the advancement of dentin adhesive systems. μTBS test has a greater discriminative capability than the traditional macro-shear bond test. During the early stage of its development, the authors predicted that this testing method would enable evaluation of the adhesive performances of resins to excavated carious or sclerotic dentin and the regional bond strengths of various portions of the cavity. In addition, they also stated the possibility of comparing the long-term stability of resin adhesion at various portions of the cavity walls on teeth extracted at various times after insertion of bonded restorations. In this review, we discussed the historical background, inception and the application of the μTBS test and proposed directions for further improvement of this testing method.
• Evaluation of shade matching of a novel supra-nano filled esthetic resin composite employing structural color using simplified simulated clinical cavities.

  Fei Chen, Yu Toida, Rafiqul Islam, Arefin Alam, Abu Faem Mohammad Almas Chowdhury, Monica Yamauti, Hidehiko Sano

  Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.] 33 (6) 874 - 883 2020/11/14 

  OBJECTIVE: To evaluate the shade matching ability of a novel supra-nano filled esthetic resin composite employing structural color technology using simplified simulated clinical cavities. Filler morphology and light transmittance characteristics were also evaluated. MATERIALS AND METHODS: One-hundred and twenty frames of resin composite were built in A1, A2, A3, and A4 shades to simulate Class I cavities (diameter = 4 mm, height = 2 mm). For each shaded frame, cavities were filled with three different types of filler containing resin composites (n = 10): supra-nano filled (SN filled) resin composite, microhybrid filled (MH filled) resin composite, and clustered-nano filled (CN filled) resin composite. Color parameters were calculated using CIELAB (△Eab ) and CIEDE2000 (△E00 ). Data were analyzed using one-way analysis of variance (ANOVA), followed by Duncan's test (α = .05). Filler morphology and light transmittance characteristics were measured to explore the role of structural color on shade matching. RESULTS: △Eab and △E00 of SN filled resin composite were significantly lower in A2, A3, and A4 shades (P < .05). CONCLUSIONS: The SN filled resin composite showed better shade matching with A2, A3, and A4 shades of resin composite frames compared to MH filled resin composite, and CN filled resin composite. CLINICAL SIGNIFICANCE: Universal-shade resin composites, which were expected to match nearly all shades, simplify the restorative procedure. Resin composite, which contained spherical supra-nano filler particles, could contribute most to its shade matching by stimulating structural color. Structural color technology may provide additional benefits for shade matching of resin composites.
• 歯科用汎用接着剤の肥厚度と機械的特性は象牙質に対する接着強度に影響を及ぼしうる(Thickness and mechanical properties of universal adhesives can affect their bond strength to dentin)

  Arefin Alam, Rafiqul Islam, Akter Rime Shamme, Readul Islam Md Refat, Matsumoto Mariko, Hoshika Shuhei, Kawamoto Chiharu, Ikeda Takatsumi, Tanaka Toru, Yamauti Monica, Chowdhury A.F.M. Almas, Sano Hidehiko

  特定非営利活動法人日本歯科保存学会学術大会プログラムおよび講演抄録集 152回 28 - 28 2020/06
• Effect of ethanol-wet bonding on porosity and retention of fiberglass post to root dentin.

  Monize Ferreira Figueiredo de Carvalho, Monica Yamauti, Cláudia Silami de Magalhães, Aline Aredes Bicalho, Carlos José Soares, Allyson Nogueira Moreira

  Brazilian oral research 34 e020  2020 

  This in vitro study aimed to assess the effects of different pretreatments used to adapt glass-fiber posts cemented to root canals with different resin cements, regarding porosity percentage and bond strength. Twelve bovine incisor roots were prepared with Largo drills. After post space preparation, the specimens were randomized into two types of pretreatment groups (n = 3): water-wet bonding and ethanol-wet bonding. After the post were cemented, the roots were stored in 100% humidity at room temperature for 7 days. The samples were scanned by microcomputed tomography (micro-CT). Images were reconstructed by NRecon software, and CTAn software was used to analyze the porosity percentage (%) at the luting interface. Evaluation of the push-out bond strength was performed by serially cutting the roots, and submitting the slices to testing. Additionally, the resin cement post-gel shrinkage values (%) were measured using the strain-gauge method (n = 10). Data were analyzed by two-way ANOVA, Tukey's test and Student's t test (a = 0.05). The roots prepared with ethanol-wet bonding using RelyX™ U200 had significantly lower porosity in the coronal and apical thirds (p < 0.05). The group prepared with ethanol-wet bonding using RelyX™ ARC presented better bond strength results in the coronal and apical thirds (p < 0.05). RelyX™ ARC (0.97%) produced a higher post-gel shrinkage value than RelyX™ U200 (0.77%). Canals pretreated with ethanol-wet bonding presented better outcomes in regard to porosity percentage and push-out bond strength.
• Variable Smear Layer and Adhesive Application: The Pursuit of Clinical Relevance in Bond Strength Testing.

  Abu Faem Mohammad Almas Chowdhury, Rafiqul Islam, Arefin Alam, Mariko Matsumoto, Monica Yamauti, Ricardo Marins Carvalho, Hidehiko Sano

  International journal of molecular sciences 20 (21) 2019/10/29 [Refereed][Not invited]
   

  The removal or modification of smear layers that cover the dentin is critical to allow the penetration of adhesive molecules and to ensure a strong bond between resin and dentin. Aiming to establish a model for clinically-relevant dentin-bond testing, we evaluated the effects of smear layers created by abrasives having similar coarseness (180-grit SiC paper; fine-grit diamond bur) and application modes (single application; double application) on the microtensile bond strengths (µTBS) of two currently available universal adhesives (G-Premio Bond; Scotchbond Universal Adhesive) and a two-step self-etch adhesive (Clearfil Megabond 2). Sixty extracted human third molars were used for the μTBS test. Data were analyzed by three-way ANOVA and Tukey's test (α = 0.05). Fracture modes were determined using stereomicroscopy. An additional 24 third molars were prepared for observation of the resin-dentin interface by TEM and adhesive-smear layer interaction by SEM. μTBS was significantly affected by the adhesives and their application modes (p < 0.001), implying that the double application of universal adhesives should be recommended to improve their performance. The effect of smear layers was not significant (p > 0.05), indicating that 180-grit SiC papers could be used to prepare dentin as a substitute for fine-grit diamond burs for dentin-bond testing in laboratory settings.
• Dental caries and developmental defects of enamel in individuals with chronic kidney disease: Systematic review and meta-analysis.

  Francisco Ivison Rodrigues Limeira, Monica Yamauti, Allyson Nogueira Moreira, Tuélita Marques Galdino, Cláudia Silami de Magalhães, Lucas Guimarães Abreu

  Oral diseases 25 (6) 1446 - 1464 2019/09 

  OBJECTIVE: To evaluate studies assessing the prevalence of dental caries and developmental defects of enamel (DDE) in individuals with chronic kidney disease (CKD) in comparison with individuals without CKD. MATERIALS AND METHODS: Electronic searches were performed in PubMed, Web of Science, Scopus, Medline via Ovid, and ProQuest databases from their inception date until February 2018. Two review authors independently selected the studies, extracted data, and assessed the methodological quality. Meta-analysis was performed. RESULTS: Twenty-seven studies were included in this study. For permanent teeth, 14 studies found that individuals without CKD had higher dental caries scores than those with CKD. However, only five studies presented results with a statistically significant difference between groups. Among the studies evaluating primary teeth, five showed that individuals without CKD had higher dental caries scores than those with CKD. Five studies showed that individuals with CKD had a significantly higher prevalence of DDE than individuals without CKD. The meta-analyses showed that individuals without CKD had significantly higher scores of dental caries teeth and surfaces than individuals with CKD. For DDE, no statistical difference between groups was observed. CONCLUSIONS: Individuals with CKD present lower dental caries scores and a higher prevalence of DDE in comparison with individuals without CKD.
• Color change of the bleached enamel treated with calcium silicate- sodium phosphate-sodium monofluorophosphate-based system.

  Gisele Carneiro, Débora Monteiro, Marcela Rodrigues, Monica Yamauti, Allyson Moreira, Cláudia Magalhães

  Journal of clinical and experimental dentistry 11 (4) e353-e359  2019/04 

  Background: The increasing demand of tooth bleaching has also increased the need of researches focusing on the durability of the resultant color. The aim of this study was to evaluate the effect of a system based on calcium silicate, sodium phosphate and sodium monofluorophosphate (Regenerate™) on color maintenance of bleached enamel considering two waiting times for the contact with a cola drink. Material and Methods: This in vitrostudy was performed on bovine enamel specimens (n = 100), bleached with 35% H2O2 and treated with: G1 Distilled water; G2 Artificial saliva; G3 RegenerateTM Serum and Toothpaste; G4 RegenerateTM Toothpaste; G5 RegenerateTM Serum. The groups G3, G4 and G5 received one application of the respective products for 3 min, in 3 consecutive days. The color parameters (ΔE, L*, a*, b*) were evaluated by spectrophotometry before and after bleaching and after surface treatments and immersion (15min) in cola drink, on the waiting times of 24 hours (T1) and 7 days (T2). The effect of surface treatments and waiting times was evaluated by Two-Way ANOVA, Kruskal-Wallis, Wilcoxon and T test (p<0.05). Results: There was no significant effect of the surface treatments (p=0.57), waiting times (p=0.97) and their interaction (p=0.47) considering ΔE. The analysis of repeated measures of the color coordinates L*, a* and b* showed a decrease of chromaticity (a*, b*) for G3, G4 and G5 and an increase of lightness (L*) for G5, after immersion in cola drink, suggesting some protection against bleached enamel pigmentation. Conclusions: RegenerateTM has a potential protective effect on bleached enamel color maintenance. The waiting times of 24 hours and 7 days for the contact with the cola drink did not influence bleached enamel color maintenance. Key words:Tooth bleaching, hydrogen peroxide, spectrophotometry, pigmentation.
• Comparison of Clinical Efficacy of Pro-Argin and NovaMin Toothpastes in Relieving Dentin Hypersensitivity: A Systematic Review and Meta-analysis.

  Diandra Costa Arantes, Francisco Ivison Rodrigues Limeira, Monica Yamauti, Allyson Nogueira Moreira, Lucas Guimarães Abreu, Cláudia Silami de Magalhães

  Oral health & preventive dentistry 17 (5) 403 - 412 2019 

  PURPOSE: To compare the clinical efficacy of toothpastes containing Pro-Argin and NovaMin as dentin hypersensitivity (DH) treatment. MATERIALS AND METHODS: A systematic review and meta-analysis based on PRISMA was conducted (PROSPERO registration CRD42018095367). Electronic searches were performed in Pubmed, Scopus, Cochrane Library, Web of Science, Virtual Health Library and Open Grey until June 2018, with the terms [pro-argin OR arginine] AND [novamin OR calcium sodium phosphosilicate OR calcium sodium phospho silicate]. Randomised and non-randomised clinical trials comparing DH reduction in adults given Pro-argin-containing toothpastes and NovaMin-containing toothpastes were included. Study selection and quality assessment with Cochrane tool were performed. In the meta-analysis, the comparison between desensitising toothpastes was assessed by standardised mean difference (SMD) with 95% confidence intervals (CI). Certainty of evidence was evaluated with GRADE. RESULTS: Five studies fulfilled the inclusion criteria. In four included studies, a reduction in the DH under tactile stimulus between baseline and post-application times for both toothpastes was demonstrated. Three studies were suitable for meta-analysis. No statistically significant difference between the two toothpastes for DH reduction was observed at immediate (SMD = -1.05, CI = -3.52;1.41), 2-week (SMD = -0.55, CI = -2.59;1.48) and 4-week (SMD = -0.49, CI = -2.78;1.81) follow-up. Certainty of the evidence was very low. Included studies presented a high risk of bias. CONCLUSIONS: Pro-argin-containing and NovaMin-containing toothpastes showed effectiveness for DH reduction. No statistically significant difference between the two toothpastes was found. Thus, both can be prescribed to treat DH in adults with equivalent effectiveness up to four weeks.
• Bioactive Two-step Approach: Promising Bonding Strategy for a One-step Self-etch Universal Adhesive.

  Linhong Wang, Fei Chen, Fan Yang, Shuhei Hoshika, Monica Yamauti, Yunqing Liu, Hidehiko Sano

  The journal of adhesive dentistry 21 (5) 413 - 421 2019 

  PURPOSE: To evaluate the potential of an additional application of two novel hydrophobic experimental adhesive resins with or without bioactive zinc fluoride glass to promote the bond strength of a one-step self-etch universal adhesive. MATERIALS AND METHODS: Three self-etch universal adhesives, G-Premio Bond (GPB), Scotchbond Universal (SBU) and Clearfil SE Bond 2 (SE2), and two experimental adhesive resins, BZF210 and BZF21, were used in this study; thus, five groups were formed: GPB, GPB+BZF210, GPB+BZF21, SBU, and SE2. The adhesives were applied to flat dentin surfaces according to each manufacturer's instructions. The microtensile bond strengths (μTBS) were evaluated after 24-h water storage. The fracture modes and interfacial structures were analyzed using SEM, while elemental analysis was performed using SEM-EDS. The data were analyzed using one-way ANOVA and the Games-Howell test (p < 0.05). RESULTS: Significantly higher μTBS was achieved by additional application of BZF210 (48.68 ± 6.59 MPa) and BZF21 (58.58 ± 2.84 MPa) compared with GPB (33.57 ± 4.22 MPa) alone. Most failures occurred above the smear layer in GBP, while more cohesive and mixed failures were observed in GBP+BZF210, GPB+BZF21, SBU, and SE2. The interfacial structures revealed that GBP+BZF210 and GPB+BZF21 had more and longer resin tags than did GPB. SEM-EDS showed a particularly high peak of zinc in GPB+BZF21. CONCLUSIONS: The bond strength of GPB was significantly improved by the additional application of BZF210 and BZF21. Using an additional bioactive hydrophobic layer on a one-step, self-etch universal adhesive can significantly improve its bonding efficacy and extend its clinical options.
• Bond Strength of Resin Cements Fixing Fiber Posts to Human and Bovine Teeth of Different Ages.

  Francisco Ivison Rodrigues Limeira, Monize Ferreira Figueiredo de Carvalho, Viviane Valquíria do Nascimento, Caroline Christine Santa-Rosa, Monica Yamauti, Allyson Nogueira Moreira, Cláudia Silami Magalhães

  The journal of adhesive dentistry 21 (5) 423 - 431 2019 

  PURPOSE: To evaluate the effect of human and bovine root dentin age on the bond strength of fiber posts fixed with resin cements. The degree of conversion (DC) of the resin cements in different root thirds also was evaluated. MATERIALS AND METHODS: Ninety-six single-rooted teeth were divided into groups according to the origin and age: young human (20-30 years), old human (over 60 years), young bovine (24-36 months) and adult bovine (over 48 months). The teeth were endodontically treated, and fiber posts were cemented with resin cements (RelyX Ultimate and RelyX U200). After 24 h, the teeth were sectioned perpendicularly and the push-out test was performed in a universal testing machine at a speed of 0.5 mm/min, until failure. One specimen from each third from each group (n = 6) was selected, and the DC of the resin cements was analyzed by FT-Raman spectroscopy. RESULTS: For both resin cements, the young human root dentin group presented the highest bond strengths and the old human root dentin group presented the lowest (p < 0.05). The bond strengths of bovine root dentin groups were not affected by aging (p > 0.05). For the DC of resin cements, there were differences among the root thirds (p < 0.05), with the lowest values observed in the apical third. CONCLUSIONS: The bond strengths were higher in the young human root canal than in the bovine substrate, with a negative effect of aging in the human substrate. The DC of dual-curing resin cements decreased from the coronal to apical root thirds.
• Viability of Bovine Teeth as a Substrate in Bond Strength Tests: A Systematic Review and Meta-analysis.

  Monize Ferreira Figueiredo de Carvalho, Amanda Carolina Neiva Leijôto-Lannes, Marcela Carolina Nunes de Rodrigues, Lilian Capanema Nogueira, Nayara Kelly Lyrio Ferraz, Allyson Nogueira Moreira, Mônica Yamauti, Lívia Guimarães Zina, Cláudia Silami de Magalhães

  The journal of adhesive dentistry 20 (6) 471 - 479 2018 

  PURPOSE: To assess whether bovine teeth can be used as viable alternatives for human teeth in tensile and shear bond strength testing. MATERIALS AND METHODS: Articles were selected from Web of Science, PubMed, Scopus, LILACS-Bireme, and BBO electronic databases using keywords obtained from Medical Subject Headings (MeSH). Of 1540 potentially eligible studies, 157 were selected for full text analysis. Five independent reviewers (Kappa = 0.89) selected the studies, abstracted information, and assessed quality based on standardized scales. After the analysis, 78 studies comparing bovine teeth to human teeth were found. Only 18 studies comparing bovine and human substrates in bond strength tests were included in the systematic review and 13 in the meta-analysis. Two authors independently selected the studies, extracted the data and assessed the risk of bias. Mean differences were obtained by comparing tensile and shear bond strengths between human and bovine teeth (permanent and deciduous) and considering enamel and dentin separately (subgroup analysis). Statistical analysis was performed using RevMan5.1, with a random-effect model, at a 5% significance level. RESULTS: No significant difference was found between human and bovine teeth in tensile tests (p = 0.41) for dentin (p = 0.86), but there was a difference for enamel (p = 0.01). Regarding shear bond strength, no significant difference was found between human and bovine teeth (p = 0.16) either for enamel (p = 0.07) or dentin (p = 0.68). Regarding shear bond strength on deciduous teeth, no significant difference was found between human and bovine substrates (p = 0.54), either for enamel (p = 0.42) or dentin (p = 0.05). Most studies were at high (low or unclear) risk of bias. CONCLUSIONS: In shear bond strength testing, bovine teeth can be a suitable alternative for permanent and deciduous human teeth, for both enamel and dentin substrates. However, they may not be suitable for enamel tensile bond strength testing. The findings are based on low quality studies (considerable heterogeneity) and should be interpreted with caution.
• Pretreatment with Sodium Fluoride Maintains Dentin Bond Strength of a Two-Step Self-Etch Adhesive after Thermal Stressing.

  Jiovanne Rabelo Neri, Jacqueline de Santiago Nojosa, Monica Yamauti, Juliano Sartori Mendonça, Sérgio Lima Santiago

  The journal of adhesive dentistry 517 - 523 2017/12/21 

  PURPOSE: To evaluate the effect of sodium fluoride and chlorhexidine digluconate on the composite-dentin bond strength of a self-etch adhesive after thermocycling. MATERIALS AND METHODS: Eighteen human third molars were prepared to expose a flat dentin surface and were divided into 3 groups (n = 6) according to the 3 cavity cleaning solutions: distilled water, 2% chlorhexidine digluconate (CHX), or 1.23% sodium fluoride (NaF). Solutions were rubbed onto dentin surfaces for 60 s, followed by bonding with Clearfil SE Bond, and a 5-mm-thick composite crown buildup. Bonded teeth were stored in distilled water for 24 h and then longitudinally sectioned to obtain bonded sticks. Half of the specimens were immediately tested in tension at 0.5 mm/min, while the remaining specimens were tested after 60,000 thermal cycles. Data were analyzed using two-way ANOVA and the Holm-Sidak method. RESULTS: There was no significant difference between the groups after 24 h (p > 0.05). Thermocycling resulted in significant bond strength reduction for distilled water and CHX (p < 0.05). When 24 h bond strengths were compared to the thermocycling group, NaF maintained its bond strength (p > 0.05), while significant reductions were observed for distilled water and CHX (p < 0.05). CONCLUSIONS: Pretreatment with NaF maintained the bond strength of Clearfil SE Bond to dentin after 60,000 thermal cycles, but pretreatment with CHX did not.
• Effect of Fluoride-containing Restorative Materials on Dentin Adhesion and Demineralization of Hard Tissues Adjacent to Restorations.

  Ana Paula Almeida Ayres, Cínthia Pereira Machado Tabchoury, Sandrine Bittencourt Berger, Monica Yamauti, Glaucia Maria Bovi Ambrosano, Marcelo Giannini

  The journal of adhesive dentistry 17 (4) 337 - 45 2015/08 

  PURPOSE: This study evaluated (1) the dentin bond strength of fluoridated restorative systems following aging and (2) the enamel/dentin microhardness around restorations after a pH-cycling regimen. MATERIALS AND METHODS: Sixty-four human third molars and four restorative systems were used. A resin-modified glass ionomer (GC Fuji II LC) was used as a fluoride-containing material in the positive control group, while Adper Easy Bond adhesive and Filtek Z350 XT composite resin, which are not fluoridated, were used together in the negative control group. Beautifil II composite resin and FL-Bond II adhesive, both fluoride-containing materials, were compared to Bond Force and Estelite Sigma Quick restorative system, which only contain fluoride in the adhesive. For dentin bond strengths, specimens of each material were fabricated for two test groups (n=8): group 1: tested after 24 h; group 2: tested after 1 year of storage in artificial saliva. Both groups were tested using a microtensile method. For the cross-sectional microhardness test, standardized Class V cavities were prepared and filled with the different restorative systems. After experiencing repeated thermocycling and being subjected to pH-cycling, the teeth were sectioned. The microhardness was measured in enamel and dentin at 50 μm from the cavity wall and at six depths in relation to the surface subjected to pH cycling. RESULTS: None of the restorative systems showed decreased bond strength after storage for one year in artificial saliva. No significant differences in microhardness were observed among the restorative materials on enamel and dentin. CONCLUSION: All the restorative systems evaluated presented stable bond strength after one year of storage. The pH cycling caused a reduction in the superficial enamel microhardness close to the cavity wall. In dentin, the demineralization affected the superficial and sub-surface areas.
• Zinc incorporation improves biological activity of beta-tricalcium silicate resin-based cement.

  Raquel Osorio, Monica Yamauti, Salvatore Sauro, Tim F Watson, Manuel Toledano

  Journal of endodontics 40 (11) 1840 - 5 2014/11 

  INTRODUCTION: Matrix metalloproteinase (MMP) inhibition may improve endodontic treatment prognosis. The purpose of this study was to determine if zinc incorporation into experimental resin cements containing bioactive fillers may modulate MMP-mediated collagen degradation of dentin. METHODS: Human dentin samples untreated and demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (OSspray, London, UK), (3) resin with beta-tricalcium silicate particles (βTCS), (4) resin with zinc-doped Bioglass 45S5, and (5) resin with zinc-doped βTCS particles. The specimens were stored in artificial saliva (for 24 hours, 1 week, and 4 weeks) and submitted to radioimmunoassay to quantify C-terminal telopeptide. Scanning electron microscopy analysis was also undertaken on dentin samples after 4 weeks of storage. RESULTS: Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced MMP activity in demineralized dentin. Resin containing Bioglass 45S5 particles exerted higher and stable protection of collagen. The presence of zinc in βTCS particles increases MMP inhibition. Different mineral precipitation was attained in dentin infiltrated with the resin cements containing bioactive fillers. CONCLUSIONS: MMP degradation of dentin collagen is strongly reduced after resin infiltration of dentin. Zinc incorporation in βTCS particles exerted an additional protection against MMP-mediated collagen degradation. However, it did not occur in resin containing Bioglass 45S5 particles, probably because of the formation of phosphate-zinc compounds.
• Nanotechnology in dentistry: drug delivery systems for the control of biofilm-dependent oral diseases.

  Francisco Fabio Oliveira de Sousa, Camila Ferraz, Lidiany K Arla de Azevedo Rodrigues, Jacqueline de Santiago Nojosa, Monica Yamauti

  Current drug delivery 11 (6) 719 - 28 2014 

  Dental disorders, such as caries, periodontal and endodontic diseases are major public health issues worldwide. In common, they are biofilm-dependent oral diseases, and the specific conditions of oral cavity may develop infectious foci that could affect other physiological systems. Efforts have been made to develop new treatment routes for the treatment of oral diseases, and therefore, for the prevention of some systemic illnesses. New drugs and materials have been challenged to prevent and treat these conditions, especially by means of bacteria elimination. "Recent progresses in understanding the etiology, epidemiology and microbiology of the microbial flora in those circumstances have given insight and motivated the innovation on new therapeutic approaches for the management of the oral diseases progression". Some of the greatest advances in the medical field have been based in nanosized systems, ranging from the drug release with designed nanoparticles to tissue scaffolds based on nanotechnology. These systems offer new possibilities for specific and efficient therapies, been assayed successfully in preventive/curative therapies to the oral cavity, opening new challenges and opportunities to overcome common diseases based on bacterial biofilm development. The aim of this review is to summarize the recent nanotechnological developments in the drug delivery field related to the prevention and treatment of the major biofilm-dependent oral diseases and to identify those systems, which may have higher potential for clinical use.
• In vitro load-induced dentin collagen-stabilization against MMPs degradation.

  Manuel Toledano, Fátima S Aguilera, Monica Yamauti, María Estrella Ruiz-Requena, Raquel Osorio

  Journal of the mechanical behavior of biomedical materials 27 10 - 8 2013/11 

  INTRODUCTION: Teeth are continuously subjected to stresses during mastication, swallowing and parafunctional habits, producing a significant reduction of the bonding efficacy in adhesive restorations. The purpose of this study was to evaluate the metalloproteinases (MMPs)-mediated dentin collagen degradation of hybrid layers created by using different demineralization processes, previous resin infiltration, and in vitro mechanical loading. METHODS: Human dentin beams (0.75×0.75×5.0mm) were subjected to different treatments: (1) untreated dentin; (2) demineralization by 37% phosphoric acid (PA) or by 0.5% M ethylenediaminetetraacetic acid (EDTA); (3) demineralization by PA, followed by application of Adper(™) Single Bond (SB); (4) demineralization by EDTA, followed by application of SB. In half of the specimens, mechanical loadings (100,000 cycles, 2Hz, 49N) were applied to dentin beams. Specimens were stored in artificial saliva. C-terminal telopeptide (ICTP), determinations (which indicates the amount of collagen degradation) (radioimmunoassay) were performed after 24h, 1 week and 4 weeks. RESULTS: Load cycling decreased collagen degradation when dentin was untreated or PA-demineralized and EDTA-treated. ICTP values increased when both PA-demineralized and EDTA-treated and infiltrated with SB dentin beams were loaded, except in samples that were subjected to EDTA treatment and SB infiltration after 4w of storage, which showed similar values of collagenolytic activity than the non loaded specimens. Load cycling preserved the initial (24h) ICTP determination at any time point, in all groups of the study, except in PA-demineralized and SB infiltrated dentin which showed an increased of collagen degradation values, over time. This same trend was observed in all groups without loading. INTERPRETATION: Mechanical loading enhances collagen's resistance to enzymatic degradation in natural and demineralized dentin. Mild acids (EDTA) lead to a lower volume of demineralized/unprotected collagen to be cleaved by MMPs. Load cycling produced an increase of collagen degradation when PA-demineralized dentin and EDTA-treated dentin were infiltrated with resin, but EDTA-treated dentin showed a constant collagenolytic degradation, over time.
• Digital image analysis method to assess the performance of conventional and self-limiting concepts in dentine caries removal.

  Manuel Toledano, Razvan Ghinea, Juan C Cardona, Inmaculada Cabello, Mónica Yamauti, María M Pérez, Raquel Osorio

  Journal of dentistry 41 Suppl 3 e31-8  2013/08 

  OBJECTIVE: To assess dentine caries removal effectiveness (CRE) and minimal invasiveness potential (MIP) of carbide and polymer burs. METHODS: Sectioned carious molars were photographed. Digital images were taken, before and after caries removal, using a Digital Single Lens Reflex camera. The following regions of interest were measured using visual criteria: Residual Infected Dentine (RI), Residual Affected Dentine (RA), Removal Sound Dentine (RA), Prepared Cavity (PC) and Removed Sound Dentine (RS). CRE was determined on basis of: relative residual infected dentine (RI/II), relative residual carious-affected dentine (RA/IA) and total relative residual dentine (RI+RA/II-IA). MIP was determined on basis of: infected dentine cavity size (PC/II), total relative cavity size (PC/II+IA), and corrected relative cavity size (PC-RS/II+IA). RESULTS: The polymer bur showed the highest preservation of carious-affected dentine after excavation, when the RA/IA ratio was studied. Both kind of burs showed similar values after assessing the RI/II and RI+RA/II-IA ratios. The infected dentine relative cavity size (PC/II) was higher when the carbide bur was used. Both burs attained similar PC/II+IA and PC-RS/II+IA ratios. CONCLUSIONS: Polymer burs accomplished the concept of minimal-invasive dentistry, showing its self-limiting ability. The minimal-invasiveness potential showed that carbide burs resulted in the worst compromise between effective and selective infected-caries removal.
• MMPs activity and bond strength in deciduous dentine-resin bonded interfaces.

  Raquel Osorio, Monica Yamauti, María E Ruiz-Requena, Manuel Toledano

  Journal of dentistry 41 (6) 549 - 55 2013/06 

  OBJECTIVES: To determine effect of ageing on deciduous dentine-resin interfaces bond strength and the metalloproteinases (MMPs) activity at the hybrid layer compared to permanent dentine. METHODS: Microtensile bond strength (MTBS) tests were performed in human deciduous and permanent dentine after 24h, 3 and 6 months using an etch and rinse adhesive. C-terminal telopeptide concentrations (ICTP) were calculated, in order to determine MMPs mediated collagen degradation at the hybrid layer. RESULTS: The highest MMPs-mediated collagen degradation values occurred in phosphoric acid demineralized dentine, ICTP values were similar for deciduous and permanent dentine after 1 week. Resin infiltration decreased collagen degradation in both dentins and ICTP values were similar to those attained by for untreated dentine. In resin infiltrated and untreated dentine specimens collagen degradation was always higher for deciduous dentine. At 24h, MTBS was higher in permanent dentine. After ageing MTBS decreased and performed similarly in both dentins. CONCLUSIONS: Higher collagenollytic activity is found in deciduous than in permanent dentine. At 24h, collagen cleavage by MMPs at the hybrid layer is higher in deciduous dentine leading to a lower MTBS. CLINICAL SIGNIFICANCE: The presence of resin monomers reduced collagen degradation when applied on demineralized dentine, but exerted protection was lower in deciduous dentine.
• Resistance to degradation of resin-dentin bonds produced by one-step self-etch adhesives.

  Manuel Toledano, Inmaculada Cabello, Monica Yamauti, Marcelo Giannini, Fátima S Aguilera, Estrella Osorio, Raquel Osorio

  Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada 18 (6) 1480 - 93 2012/12 

  The objective of this article is to evaluate the resistance to degradation of resin-dentin bonds formed with three one-step adhesives. Flat, mid-coronal dentin surfaces were bonded with the self-etching adhesives [Tokuyama Bond Force (TBF), One Up Bond F Plus (OUB), and G-Bond (GB)]. The bonded teeth were subjected to fatigue loading, chemical degradation, and stored in distilled water for four time periods (up to 12 months). Specimens were tested for microtensile bond strength and microleakage. Fractographic analysis was performed by scanning electron microscopy. Bonded interfaces were examined by light microscopy using Masson's trichrome staining. An atomic force microscope was employed to analyze phase separation and surface nanoroughness (Ra) at the polymers. Vickers microhardness and the degree of the conversion (DC) were also determined. ANOVA and multiple comparisons tests were performed. Bond strength significantly decreased after the chemical challenge, but not after load cycling. Aging decreased bond strength after 6 months in TBF and GB, in OUB after 12 months. An increase of the nonresin protected collagen zone occurred in all groups, after storing. TBF showed the highest roughness, microhardness, and DC values, and GB showed the lowest. Mild self-etch one-step adhesives (TBF/OUB) showed a higher degree of cure, lower hydrophilicity, and major resistance to degradation of resin-dentin bonds when compared to highly acidic self-etching adhesive (GB).
• A ZnO-doped adhesive reduced collagen degradation favouring dentine remineralization.

  Manuel Toledano, Monica Yamauti, María Estrella Ruiz-Requena, Raquel Osorio

  Journal of dentistry 40 (9) 756 - 65 2012/09 

  OBJECTIVES: The objective of the study was to determine the efficacy of a ZnO-doped etch and rinse adhesive in decreasing MMPs-mediated collagen degradation at the resin-dentine hybrid layer, and increasing bonding stability. METHODS: C-terminal telopeptide concentrations (ICTP) were determined after 24h, 1wk and 4wk in human dentine beams. Dentine was treated: (1) 37% phosphoric acid for 15s (PA), (2) PA-etched dentine infiltrated with Single Bond (SB), (3) PA-etched dentine infiltrated with ZnO doped SB (ZnO particles--10wt%--were added to the bonding resin) (ZnO-SB), and (4) Clearfil SE Bond primed-dentine was infiltrated with Clearfil SE bonding resin (CSE). Microtensile bond strength (MTBS) was assessed for the different groups at 24h and after 3months. Debonded dentine surfaces were studied by scanning electron microscopy. RESULTS: MMPs-mediated collagen degradation occurred in demineralized dentine (PA). Resin infiltration decreased collagen degradation. The lowest collagen degradation was found for Zn-doped SB, followed by CSE. When these adhesives were applied, ICTP values did not change throughout the study period. At 24h, similar MTBS was attained for all adhesives. Only SB decreased MTBS after three months. CONCLUSIONS: Addition of ZnO particles to SB produced a reduction in dentine collagen degradation and increased resin-dentine bonds durability. In Zn-doped adhesive interfaces, a calcium phosphate layer and tubular occlusion was encountered at the debonded interface. CLINICAL SIGNIFICANCE: ZnO particles addition into the bonding resin of SB makes a breakthrough to prevent the hybrid layer degradation and to preserve its bonding efficacy overtime.
• Experimental resin cements containing bioactive fillers reduce matrix metalloproteinase-mediated dentin collagen degradation.

  Raquel Osorio, Monica Yamauti, Salvatore Sauro, Thimoty F Watson, Manuel Toledano

  Journal of endodontics 38 (9) 1227 - 32 2012/09 

  INTRODUCTION: Collagen dentin matrix may represent a suitable scaffold to be remineralized in the presence of bioactive materials. The purpose of this study was to determine if experimental resin cements containing bioactive fillers may modulate matrix metalloproteinase-mediated collagen degradation of etched dentin. METHODS: Human dentin beams demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (Sylc; OSspray Ltd, London, UK), and (3) resin with β-tricalcium phosphate-modified calcium silicate cement (HCAT-β) particles. The filler/resin ratio was 40/60 wt%. The specimens were stored in artificial saliva, and the determination of C-terminal telopeptide (ICTP) was performed by radioimmunoassay after 24 hours, 1 week, and 4 weeks. Scanning electron microscopic analysis of dentin surfaces after 4 weeks of storage was also executed. RESULTS: Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced the MMP activity in demineralized dentin. Resin-containing Bioglass 45S5 particles exerted higher and more stable protection of collagen at all tested dentin states and time points. HCAT-β induced collagen protection from MMPs only in EDTA-treated specimens. Dentin remineralization was achieved when dentin was infiltrated with the resin cements containing bioactive fillers. CONCLUSIONS: MMP degradation of dentin collagen is strongly reduced in resin-infiltrated dentin. The inclusion of Bioglass 45S5 particles exerted an additional protection of collagen during dentin remineralization.
• Differential nanofiller cluster formations in dental adhesive systems.

  Estrella Osorio, Manuel Toledano, Monica Yamauti, Raquel Osorio

  Microscopy research and technique 75 (6) 749 - 57 2012/06 

  UNLABELLED: Nanofillers are added to dental adhesives to improve mechanical properties of the hybrid layer. Ethanol or water added to the demineralized dentin to improve adhesive infiltration may produce filler aggregation. OBJECTIVE: To assess the effect of 5 vol% water or ethanol addition on nanoparticles distribution in dental adhesives. METHODS: Six available commercial adhesives systems were selected: Clearfil SE Bond (CSE), Clearfil Protect Bond (CPB), FL-Bond (FLB), Clearfil S3 (CS3), Bond Force (BF), One Up Bond F plus (OUB), and an experimental adhesive system without filler (EXP). Polymer films were obtained by adding 0 (control) or 5 vol% water or ethanol into the bonding resins. Preparations were light-cured (40 s). Three specimens were analyzed for each mixture. Three phases and 3D images were taken from each specimen by means of an atomic force microscope in taping mode (TM/AFM). Cluster sizes and surface nanoroughness were assessed. RESULTS: Control specimens from CSE, FLB, OUB, and BF presented clusters. The addition of solvents lead to particles aggregation in tested bonding resins. Ethanol addition produced more aggregates, particularly in adhesives containing fluoraluminosilicate as fillers. CONCLUSIONS: Nanofillers aggregation occurred in all adhesive systems in presence of additional solvents. In general, aggregate sizes were higher after the addition of ethanol. Formed clusters size values are always above the dimensions of the spaces existing between the demineralized collagen fibers.
• Differential resin-dentin bonds created after caries removal with polymer burs.

  Manuel Toledano, Inmaculada Cabello, Monica Yamauti, Raquel Osorio

  Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada 18 (3) 497 - 508 2012/06 

  The objective of this article was to investigate the effect of carbide and polymer burs caries removal methods on the bond strength of different adhesives to dentin. Resin restorations were performed in sound and caries-affected dentin, after using polymer or carbide burs and bonding with four different adhesive (Single bond, SB; Clearfil SE bond, SEB; FL-Bond II, FLB; and Fuji II-LC, FUJI). Microtensile bond strength (MTBS) was measured. Data were analyzed with ANOVA and Student-Newman-Keuls tests. Debonded surfaces were observed by scanning electron microscopy. Bonded interfaces were examined using light microscopy (Masson's trichrome staining). In sound dentin, MTBS was similar for SEB and SB, and higher than that of FLB and FUJI. Bond strength to carbide bur prepared dentin was similar for SB, SEB, and FLB; FUJI presented the lowest. SB applied on polymer bur excavated dentin presented similar values to those of the carbide bur group; MTBS attained by SEB, FLB, and FUJI decreased when bonding to dentin treated with polymer burs; FUJI yielded pretesting failures in all specimens. Polymer burs created a thick smear layer that was not infiltrated by tested self-etching agents. The bonding effectiveness of self-etching and glass-ionomer-like adhesives to dentin decreased when polymer burs were used.
• Characterization of micro- and nanophase separation of dentin bonding agents by stereoscopy and atomic force microscopy.

  Manuel Toledano, Monica Yamauti, Estrella Osorio, Francesca Monticelli, Raquel Osorio

  Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada 18 (2) 279 - 88 2012/04 

  The aim was to study the effect of solvents on the phase separation of four commercial dental adhesives. Four materials were tested: Clearfil™ SE Bond (CSE), Clearfil Protect Bond (CPB), Clearfil S3 Bond (CS3), and One-Up Bond F Plus (OUB). Distilled water or ethanol was used as a solvent (30 vol%) for microphase separation studies, by stereoscopy. For nanophase images, the mixtures were formulated with two different solvent concentrations (2.5 versus 5 vol%) and observed by atomic force microscopy. Images were analyzed by using MacBiophotonics ImageJ to measure the area of bright domains. Macrophase separations, identified as a loss of clarity, were only observed after mixing the adhesives with water. Nanophase separations were detected with all adhesive combinations. The area of bright domains ranged from 132 to 1,145 nm² for CSE, from 15 to 285 nm² for CPB, from 149 to 380 nm² for CS3, and from 26 to 157 nm² for OUB. In water-resins mixtures, CPB was the most homogeneous and OUB showed the most heterogeneous phase formation. In ethanol-resin mixtures, CSE attained the most homogeneous structure and OUB showed the most heterogeneous phase. Addition of 5 vol% ethanol to resins decreased the nanophase separation when compared with the control materials.
• Bleaching agents increase metalloproteinases-mediated collagen degradation in dentin.

  Manuel Toledano, Monica Yamauti, Estrella Osorio, Raquel Osorio

  Journal of endodontics 37 (12) 1668 - 72 2011/12 

  INTRODUCTION: Tooth bleaching is based on hydrogen peroxide application. The Objective of this study was to determine whether dental bleaching agents affect metalloproteinases-mediated dentin collagen degradation. METHODS: Human dentin specimens were subjected to different treatments: (1) untreated dentin; (2) demineralization by 37% phosphoric acid (PA); (3) demineralization by 37% PA, followed by application of Single Bond (SB); (4) 2 immersions of 7 days each in a nonvital bleaching agent, followed by PA; (5) 2 immersions of 7 days each in nonvital bleaching, followed by PA and SB application; (6) 3 immersions by using in-office bleaching gel for 20 minutes; (7) 3 immersions by using in-office bleaching gel for 20 minutes plus activation with a light source; and (8) immersion in home bleaching gel for 8 hours per day during 3 weeks. Specimens were stored in artificial saliva. C-terminal telopeptide determinations (radioimmunoassay) were performed after 24 hours, 1 week, and 4 weeks. RESULTS: Bleaching agents increased collagen degradation, but C-terminal telopeptide of type I collagen (ICTP) values were higher when dentin was PA-demineralized. Nonvital bleaching plus PA promoted the highest collagenolytic activity, which was reduced after SB infiltration. Halogen light application did not influence ICTP values. At 24 hours, home bleaching exhibited high collagenolytic activity, which decreased up to 4 weeks. After 4 weeks of storage, all bleaching procedures showed similar values of collagen degradation, which were not different from those of PA-demineralized and resin-infiltrated dentin. CONCLUSIONS: All tested bleaching agents increase matrix metalloproteinases-mediated collagen degradation in dentin. This effect was not completely reverted after 4 weeks. Home bleaching induced the highest collagen degradation.
• Zinc-doped dentin adhesive for collagen protection at the hybrid layer.

  Raquel Osorio, Monica Yamauti, Estrella Osorio, Julio S Román, Manuel Toledano

  European journal of oral sciences 119 (5) 401 - 10 2011/10 

  The aim of the study was to ascertain whether the addition of zinc to adhesives may decrease metalloproteinase-mediated collagen degradation without affecting bonding efficacy. Human dentin beams were treated with phosphoric acid, with Clearfil SE Bond Primer or with Clearfil SE Bond Primer plus ZnCl(2) (2 wt%). Acid-etched dentin was infiltrated with Single Bond, Single Bond plus ZnCl(2) (2 wt%), or Single Bond plus ZnO nanoparticles (10 wt%), and Clearfil SE Bond-primed dentin was infiltrated with Clearfil SE Bonding resin, Clearfil SE-Bonding resin with ZnCl(2) (2 wt%), or Clearfil SE-Bonding resin with ZnO nanoparticles (10 wt%). The C-terminal telopeptide concentrations were determined 24 h, and 1 and 4 wk after treatment. Microtensile bond strength to dentin was determined for the tested adhesives. Matrix metalloproteinases-mediated collagen degradation occurred in acid-etched and SE-primed dentin. Resin infiltration decreased collagen degradation. Lower collagen degradation was found for SE Bond than for Single Bond. Zinc-doped Single Bond resin always reduced collagen degradation, the ZnO particles being more effective than ZnCl(2) . Zinc-doped SE Bond reduced the liberation of C-terminal telopeptide only at 24 h. Bond strength to dentin was not decreased when Zn-doped resins were employed, except when ZnCl(2) was added to SE Primer. Zinc-doped resin reduced collagen degradation in Single Bond hybrid layers, but did not affect bond strength. The addition of zinc to SE Bond had no beneficial effects.
• Effect of dentin etching and chlorhexidine application on metalloproteinase-mediated collagen degradation.

  Raquel Osorio, Mónica Yamauti, Estrella Osorio, María E Ruiz-Requena, David Pashley, Franklin Tay, Manuel Toledano

  European journal of oral sciences 119 (1) 79 - 85 2011/02 

  Dentin matrix metalloproteinases (MMPs) are involved in the degradation of collagen in resin-dentin interfaces. This study evaluated whether collagen degradation can be prevented by chlorhexidine digluconate (CHX) after different dentin demineralization procedures. The demineralization of human dentin was performed with phosphoric acid (PA), EDTA or acidic monomers (Clearfil SE Bond and Xeno V). Specimens were stored (for 24 h, or for 1 or 3 wk) in the presence or absence of CHX. In half of the groups, active MMP-2 was incorporated into the storage solution. At the end of each storage period, the C-terminal telopeptide (ICTP) concentration (which indicates the amount of collagen degradation) was measured in the storage solution. Collagen degradation was higher in PA- and EDTA-demineralized dentin. Chlorhexidine digluconate reduced collagen degradation in these groups only for 24 h. When dentin was demineralized with Clearfil SE Bond or Xeno V, collagen degradation was reduced by up to 30%, but the addition of exogenous MMP-2 significantly increased collagen degradation. In self-etchant-treated dentin, the inhibitory effect of CHX on MMPs lasted for up to 3 wk. Treating dentin with EDTA, PA or self-etching agents produces enough demineralization to permit cleavage of the exposed collagen. Monomer infiltration may exert protection on demineralized collagen, probably through immobilization of MMPs. The partial inhibitory action of CHX on MMP activity produced by self-etching adhesives was prolonged compared with the short-acting PA- or EDTA-treated dentin.
• Effect of pulse duration of Er: YAG laser on dentin ablation.

  Yuki Nishimoto, Masayuki Otsuki, Monica Yamauti, Testuya Eguchi, Yasuharu Sato, Richard M Foxton, Junji Tagami

  Dental materials journal 27 (3) 433 - 9 0287-4547 2008/05 

  The present study examined the effects on dentin ablation efficiency arising from various pulse durations of Er: YAG laser at a fixed energy fluence. Ten flat human dentin disks were prepared and exposed to an Er: YAG laser at 1 pps for three seconds at pulse durations of 100-500 microsec with 150 mJ/pulse (40.0 J/cm x pulse). The depth and diameter of the ablated dentin were measured and the ablation volume was estimated. Irradiated surfaces and cross-sections were observed using a SEM. Depth of the removed dentin increased and the diameter of the spot decreased without a change in the estimated volume at increased pulse durations. SEM observation of the irradiated surfaces revealed that there were no morphological differences when the pulse duration was changed. When the specimens were cross-sectioned, the ablated dentin had a dome shape and there was a dark layer under the irradiated surface.
• Effect of bacterial collagenase on resin-dentin bonds degradation.

  Manuel Toledano, Raquel Osorio, Estrella Osorio, Fátima S Aguilera, Monica Yamauti, David H Pashley, Franklin Tay

  Journal of materials science. Materials in medicine 18 (12) 2355 - 61 0957-4530 2007/12 

  The objective of this study is to evaluate the effect of a bacterial collagenase on the degradation of resin-dentin bonds. Human dentin surfaces were bonded with: an etch-&-rinse self-priming adhesive (SB), a two-step self-etching primer/adhesive (SEB), and a 1-step self-etching adhesive (OUB). Composite build-ups were constructed. The bonded teeth were stored (24 h, 3 months, 1 year) in distilled water or in a buffered bacterial collagenase solution. Half of the specimens were stored as intact bonded teeth (Indirect Exposure/IE). The other half were sectioned into beams prior to storage (Direct Exposure/DE). After storage the intact teeth were sectioned into beams and all specimens were tested for microtensile bond strengths (MTBS). ANOVA and multiple comparisons tests were performed. Fractographic analysis was performed by scanning electron microscopy. The inclusion of bacterial collagenase in the storing solution did not lower the MTBS values over those seen in specimens stored in water. SB and SEB bonds strength were equal, and were superior to OUB. After 3 months of DE, SB and OUB bonded specimens showed decreases in MTBS; similar reductions required 1 year for SEB/DE. MTBS did not decrease in IE specimens except for OUB. Resin and collagen dissolution were evident in DE groups after storing.
• Influence of hydrostatic pulpal pressure on the microtensile bond strength of all-in-one self-etching adhesives.

  Keiichi Hosaka, Masatoshi Nakajima, Francesca Monticelli, Marcela Carrilho, Monica Yamauti, Juthatip Aksornmuang, Yoshihiro Nishitani, Franklin R Tay, David H Pashley, Junji Tagami

  The journal of adhesive dentistry 9 (5) 437 - 42 1461-5185 2007/10 

  PURPOSE: To evaluate the microtensile bond strength (microTBS) of two all-in-one self-etching adhesive systems and two self-etching adhesives with and without simulated hydrostatic pulpal pressure (PP). MATERIALS AND METHODS: Flat coronal dentin surfaces of extracted human molars were prepared. Two all-in-one self-etching adhesive systems, One-Up Bond F (OBF; Tokuyama) and Clearfil S3 Bond (Tri-S, Kuraray Medical) and two self-etching primer adhesives, Clearfil Protect Bond (PB; Kuraray) and Clearfil SE Bond (SE; Kuraray) were applied to the dentin surfaces according to manufacturers' instructions under either a pulpal pressure (PP) of zero or 15 cm H2O. A hybrid resin composite (Clearfil AP-X, Kuraray) was used for the coronal buildup. Specimens bonded under PP were stored in water at 37 degrees C under 15 cm H2O for 24 h. Specimens not bonded under PP were stored under a PP of zero. After storage, the bonded specimens were sectioned into slabs that were trimmed to hourglass-shaped specimens, and were subjected to microtensile bond testing (microTBS). The bond strength data were statistically analyzed using two-way ANOVA and the Holm-Sidak method for multiple comparison tests (alpha = 0.05). The surface area percentage of different failure modes for each material was also statistically analyzed with three one-way ANOVAs and Tukey's multiple comparison tests. RESULTS: The microTBS of OBF and Tri-S fell significantly under PP. However, in the, PB and SE bonded specimens under PP, there were no significant differences compared with the control groups without PP. CONCLUSIONS: The microTBS of the two all-in-one adhesive systems decreased when PP was applied. However, the microTBS of both self-etching primer adhesives did not decrease under PP.
• Durability of resin-dentin bonds: effects of direct/indirect exposure and storage media.

  Manuel Toledano, Raquel Osorio, Estrella Osorio, Fátima S Aguilera, Monica Yamauti, David H Pashley, Franklin Tay

  Dental materials : official publication of the Academy of Dental Materials 23 (7) 885 - 92 0109-5641 2007/07 

  OBJECTIVES: To evaluate the longevity of resin-dentin bonds of three adhesives using different storage media and specimen size. METHODS: Flat dentin surfaces from extracted human third molars were bonded with: a two-step etch-and-rinse self-priming adhesive (Single Bond), a two-step self-etching adhesive (Clearfil SE Bond), and a one-step self-etching adhesive (One-Up Bond F). Composite build-ups were constructed. The bonded teeth were stored under three conditions: dry, distilled water, or mineral oil. Half of the specimens were stored as intact bonded teeth (Indirect Exposure/IE). The other half were first sectioned into beams and stored under same conditions (Direct Exposure/DE). After storage periods of 24h, 3 months or 1 year, the intact teeth (IE) were sectioned into beams and both subgroups (DE and IE) were tested for microtensile bond strengths. Results were analyzed with multiple ANOVA and Student-Newman-Keuls tests. Fractographic analysis was performed by SEM. RESULTS: After 24h, Single Bond and Clearfil SE Bond performed equally and were superior to One-Up Bond F. After 3 months of DE to water storage, decreases in bond strengths were observed for Single Bond and One-Up Bond F, this decrease occurred for Clearfil SE Bond after 12 months of water storage. Bonded specimens aged in dry did not alter bond strengths over time. Bond strength increased when Single Bond was stored in mineral oil after 3 and 12 months. Micromorphological alterations were evident after water storage. SIGNIFICANCE: Although dentin bond strength of all the adhesives fell over time in DE, SE Bond fells the least.
• Effect of simulated pulpal pressure on all-in-one adhesive bond strengths to dentine.

  Keiichi Hosaka, Masatoshi Nakajima, Monica Yamauti, Juthatip Aksornmuang, Masaomi Ikeda, Richard M Foxton, David H Pashley, Junji Tagami

  Journal of dentistry 35 (3) 207 - 13 0300-5712 2007/03 

  OBJECTIVES: To evaluate the durability of all-in-one adhesive systems bonded to dentine with and without simulated hydrostatic pulpal pressure (PP). METHODS: Flat dentine surfaces of extracted human molars were prepared. Two all-in-one adhesive systems, One-Up Bond F (OBF) (Tokuyama Corp., Tokyo, Japan), and Fluoro Bond Shake One (FBS) (Shofu Co., Kyoto, Japan) were applied to the dentine surfaces under either a PP of 0 or 15cm H(2)O. Then, resin composite build-ups were made. The specimens bonded under pressure were stored in 37 degrees C water for 24h, 1 and 3 months under 15cm H(2)O PP. Specimens not bonded under pressure were stored under zero PP. After storage, the specimens were sectioned into slabs that were trimmed to hourglass shapes and subjected to micro-tensile bond testing (muTBS). The data were analysed using two-way ANOVA and Holm-Sidak HSD multiple comparison tests (alpha=0.05). RESULTS: The muTBS of OBF fell significantly (p<0.05) when PP was applied during bonding and storage, regardless of storage time. In contrast, although the muTBS of OBF specimens bonded and stored without hydrostatic pressure storage fell significantly over the 3 months period, the decrease was less than half as much as specimens stored under PP. In FBS bonded specimens, although there was no significant difference between the muTBS with and without hydrostatic pulpal pressure at 24h, by 1 and 3 months of storage under PP, significant reductions were seen compared with the control group without PP. CONCLUSION: The muTBS of OBF bonded specimens was lowered more by simulated PP than by storage time; specimens bonded with FBS were not sensitive to storage time in the absence of PP, but showed lower bond strengths at 1 and 3 months in the presence of PP.
• Evaluation of antibacterial and fluoride-releasing adhesive system on dentin--microtensile bond strength and acid-base challenge.

  Mirela Sanae Shinohara, Monica Yamauti, Go Inoue, Toru Nikaido, Junji Tagami, Marcelo Giannini, Mario Fernando de Goes

  Dental materials journal 25 (3) 545 - 52 0287-4547 2006/09 

  This study evaluated the influence of a fluoride-containing adhesive on microtensile bond strength (microTBS) to dentin, as well as analyzed the dentin-adhesive interface after acid-base challenge. Experimental groups were: G1--Clearfil SE Bond control (SE); G2--Clearfil Protect Bond control (PB); G3--Primer[SE]/Adhesive[PB]; G4--Primer[PB]/Adhesive[SE]. For microTBS evaluation, dentin surfaces were ground, bonded, and composite resin crowns were built up to obtain beams to be tested. For interfacial analysis, adhesive system was applied on dentin surface and a low-viscosity resin was placed between two dentin disks. Then, the specimens were subjected to acid-base challenge, sectioned, and polished to be observed by SEM. microTBS data showed no statistical differences among the groups (GI: 51.3, G2: 47.6, G3: 55.0, G4: 53.9; mean in MPa). Through SEM, it was observed that a thick acid-base resistant zone adjacent to the hybrid layer was created only when the fluoride-releasing adhesive was used. In conclusion, the presence of fluoride in an adhesive contributed significantly to preventing secondary caries, and did not interfere with dentin-adhesive bond strength.
• Bonding durability of a self-etching primer system to normal and caries-affected dentin under hydrostatic pulpal pressure in vitro.

  Masatoshi Nakajima, Keiichi Hosaka, Monica Yamauti, Richard M Foxton, Junji Tagami

  American journal of dentistry 19 (3) 147 - 50 0894-8275 2006/06 

  PURPOSE: To evaluate the bonding durability of a self-etching primer system to normal and caries-affected dentin under hydrostatic pulpal pressure. METHODS: 18 extracted human molars with occlusal caries were used. Their occlusal dentin surfaces were ground flat to expose normal and caries-affected dentin using #600 SiC paper under running water. Clearfil SE Bond was placed on the dentin surface including the caries-affected dentin according to the manufacturer's instructions and then the crowns were built up with resin composite (Clearfil AP-X) under either a pulpal pressure of 15 cm H2O or none (control). The bonded specimens were stored in 100% humidity for 1 day (control) or for 1 week and 1 month with hydrostatic pulpal pressure. After storage, the specimens were serially sectioned into 0.7 mm-thick slabs and trimmed to an hour-glass shape with a 1 mm2 cross-section, isolated by normal or caries-affected dentin, and then subjected to the micro-tensile bond test. Data were analyzed by two-way ANOVA and Tukey's test (P< 0.05). RESULTS: Hydrostatic pulpal pressure significantly reduced the bond strength to normal dentin after 1-month storage (P< 0.05), but did not affect the bond strength to caries-affected dentin.
• Influence of curing method and storage condition on microhardness of dual-cure resin cements.

  Rena Shimura, Toru Nikaido, Monica Yamauti, Masaomi Ikeda, Junji Tagami

  Dental materials journal 24 (1) 70 - 5 0287-4547 2005/03 

  This study evaluated the influence of curing method and storage condition on the microhardness of dual-cure resin cements: Panavia F 2.0 (PF) and Nexus 2 (NX). The specimens were either light-cured (LC) or chemically cured in darkness (CC). After 24 hours of storage in dry chamber (Dry) or distilled water (DW), the specimens were sectioned and polished. The microhardness of resin cement matrix was measured using a nanoindentation tester (ENT-1100). The data (n = 6) were statistically analyzed with t-test, two-way ANOVA (p < 0.05), and Tukey HSD test (alpha = .05). It was found that the factors of curing method and storage condition had significant effect on microhardness. For both PF and NX, LC presented higher microhardness than CC, while DW showed higher microhardness than Dry. In conclusion, dual-cure resin cements could achieve high degree of cure when light-cured. In addition, the microhardness of the resin cements evaluated did not decrease when kept in water.
• Microhardness and Young's modulus of a bonding resin cured with different curing units.

  Monica Yamauti, Toru Nikaido, Masaomi Ikeda, Masayuki Otsuki, Junji Tagami

  Dental materials journal 23 (4) 457 - 66 0287-4547 2004/12 

  This study evaluated the microhardness and Young's modulus of a photocurable bonding resin, Clearfil SE Bond (SE), cured with four curing units at different distances. The curing units used were: Candelux (Quartz-tungsten halogen), Lux-O-Max (Blue light emitting diode), Arc-light (Plasma-arc), and Rayblaze (Metal halide). Discs of bonding resin were prepared using vinyl molds and were photocured at the top surface with light tip at three different distances (contact, 2 and 4 mm). After 24 hours of storage in water at 37 degrees C, the specimens were sectioned into halves, embedded in epoxy resin, and polished. The microhardness and Young's modulus of this bonding resin were measured using a nanoindentation tester. Six specimens were prepared for each group. The data was statistically analyzed using two-way ANOVA test and Tukey multiple comparison test (p < 0.01). The microhardness of SE was affected by light source and distance, as was Young's modulus. Candelux and Rayblaze presented the highest hardness and Young's modulus results. Both properties presented high values when the curing unit tip was maintained in contact with the irradiated surface. Increasing the distance between the curing unit tip and the irradiated surface decreased the hardness and Young's modulus of SE.

Conference Activities & Talks

• Dental developmental defects - an adhesion challenge  [Invited]

  Monica Yamauti

  XIX Integrated Dental Journey of Academics at the Federal University of Ceara  2021/10
• Developmental defects of enamel - an adhesion challenging  [Invited]

  Monica Yamauti

  154th Spring Meeting of the Japanese Society for Conservative Dentistry  2021/06
• The paths to internationalization: experiences and perspectives  [Invited]

  Monica Yamauti

  50th Anniversary of Operative Dentistry Department, Bauru School of Dentistry, University of Sao Paulo  2020

Works

• General Dentist

  1997/06 -1999/10
• General Dentist

  1995/04 -1996/11

MISC

• 4-META/MMA-TBB系レジンセメント接着阻害因子長期処理に対するアクセルの効果

  鈴木 一矢, 袁 媛, 星加 修平, 田中 享, ヤマウチ モニカ, 佐野 英彦  特定非営利活動法人日本歯科保存学会学術大会プログラムおよび講演抄録集  154回-  83  -83  2021/05
• 新規フロアブルレジン「CLM-01」のV級窩洞における窩壁適合性と窩底部象牙質への接着強さ

  高垣 智博, 保坂 啓一, モニカ・ヤマウチ, 中島 正俊, 田上 順次  日本歯科保存学雑誌  48-  (春季特別)  54  -54  2005/05
• Effect of LED curing units on shear bond strength

  YAMAUTI Monica  日歯保存誌  44-  P14  2001
• Effect of LED curing units on shear bond strength

  YAMAUTI Monica  日歯保存誌  44-  99  -99  2001

Educational Activities

Teaching Experience

Committee Membership

• 2019/08 - Today   Operative Dentistry - Journal   Review Board
• 2019/01 - Today   Journal of Dental Research   Review Editorial Board
• 2015/01 -2018/05   Universidade Federal de Minas Gerais   Tooth Biobank

Social Contribution

Social Contribution

Social Contribution

• Honorary Consul of Brazil in Sapporo

  Date (from-to) : 2019/08/13-2021/07/31

  Role : Others

  Sponser, Organizer, Publisher  : Federal Republic of Brazil

Academic Contribution

• Editorial Review Board of the Journal of Dental Research

  Date (from-to) :2019/06/01-Today

  Role: Review

  Type: Peer review etc

  Organizer, responsible person: IADR