Discrimination and dental students: What is the reality in Brazilian institutions?

INTRODUCTION: This study aimed to evaluate whether there is discrimination in the dental educational environment, assess the main reasons for the discriminatory events, and if there is an association between discriminatory episodes and sociodemographic characteristics of undergraduate dental students. MATERIALS AND METHODS: This observational cross-sectional study was conducted with a self-administered questionnaire to students enrolled in three Brazilian dental schools. Questions included sociodemographic characteristics and the occurrence of discriminatory episodes in the dental academic environment. Descriptive analysis was performed in RStudio 1.3 (R Core Team, RStudio, Inc., Boston, USA) software and the associations were tested using Pearson's chi-square test, considering 95% confidence intervals. RESULTS: A total of 732 dental students were included, with a response rate of 70.2%. The vast majority of students were female (66.9%), with white/yellow skin colour (67.9%), and with a mean age of 22.6 (SD 4.1) years. Sixth-eight percent of students reported having experienced some discrimination in the academic environment and most reported feeling uncomfortable with the episode. The main reasons to have been discriminated against raised by students were specific behaviour/habit, have specific moral, ethical, and aesthetic values, gender, and socioeconomic status or social class. The occurrence of discriminatory episodes was associated with female gender (p = .05), non-heterosexual sexual orientation (p < .001), studying in public institutions (p < .001), receiving an institutional scholarship (p = .018), and being in the final undergraduate cycle (p < .001). CONCLUSION: The occurrence of discriminatory episodes was common in Brazilian dental higher education. Discriminatory situations generate traumas and psychological marks, causing a loss of diversity within the academic environment that leads to loss of productivity, creativity, and innovation. Thus, strong institutional policies against discrimination are crucial to create a healthy dental academic environment.

Is dentin biomodification with collagen cross-linking agents effective for improving dentin adhesion? A systematic review and meta-analysis.

Objectives: The aim of this investigation was to evaluate the effectiveness of collagen cross-linking agents (CCLAs) used in combination with the adhesive technique in restorative procedures. Materials and Methods: In this systematic review, the authors followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. An electronic search was performed using PubMed, Scopus, Web of Science, Cochrane Library, LILACS, and DOSS, up to October 2020. The gray literature was also researched. Only randomized clinical trials were selected. Results: The selection process yielded 3 studies from the 838 retrieved. The addition of CCLAs in the retention of restorations increased the number of events. The postoperative sensitivity scores and marginal adaptation scores showed no significant difference between the CCLA and control groups, and the marginal pigmentation scores showed a significant increase in the CCLA group. There were no caries events in any group throughout the evaluation period. Conclusions: This systematic review showed that there is no clinical efficacy to justify the use of CCLAs in the protocols performed.

In-vitro models of biocompatibility testing for restorative dental materials: From 2D cultures to organs on-a-chip.

Dental caries is a biofilm-mediated, diet-modulated, multifactorial and dynamic disease that affects more than 90% of adults in Western countries. The current treatment for decayed tissue is based on using materials to replace the lost enamel or dentin. More than 500 million dental restorations are placed annually worldwide, and materials used for these purposes either directly or indirectly interact with dentin and pulp tissues. The development and understanding of the effects of restorative dental materials are based on different in-vitro and in-vivo tests, which have been evolving with time. In this review, we first discuss the characteristics of the tooth and the dentin-pulp interface that are unique for materials testing. Subsequently, we discuss frequently used in-vitro tests to evaluate the biocompatibility of dental materials commonly used for restorative procedures. Finally, we present our perspective on the future directions for biological research on dental materials using tissue engineering and organs on-a-chip approaches. STATEMENT OF SIGNIFICANCE: Dental caries is still the most prevalent infectious disease globally, requiring more than 500 million restorations to be placed every year. Regrettably, the failure rates of such restorations are still high. Those rates are partially based on the fact that current platforms to test dental materials are somewhat inaccurate in reproducing critical components of the complex oral microenvironment. Thus, there is a collective effort to develop new materials while evolving the platforms to test them. In this context, the present review critically discusses in-vitro models used to evaluate the biocompatibility of restorative dental materials and brings a perspective on future directions for tissue-engineered and organs-on-a-chip platforms for testing new dental materials.

Cashew nut shell liquids: Antimicrobial compounds in prevention and control of the oral biofilms.

OBJECTIVE: The aim was to evaluate the antibacterial and antibiofilm activity of natural (n-CNSL) and technical (t-CNSL) cashew nut shell liquid against streptococci and enterococci related to dental caries and chronic apical periodontitis, respectively. MATERIAL AND METHODS: Minimum inhibitory concentrations (MIC) and minimal bactericidal concentration (MBC) were determined to assess the antimicrobial effect of both CNSLs (n-CSNL and t-CNSL) against S. oralis ATCC 10557, S. sobrinus ATCC 6715, S. parasanguinis ATCC 903, S. mutans UA 159 and E. faecalis ATCC 19433. The antibiofilm activity was evaluated by total biomass quantification, colony forming unit (CFU) counting and scanning electron microscopy (SEM). Furthermore, cytotoxic effect of the substances was evaluated on L929 and HaCat cell lines by MTS assay. RESULTS: The n-CNSL and t-CNSL showed inhibitory and bactericidal effect against all strains tested in this study, with MIC and MBC values ranging from 1.5 to 25 µg/mL. Overall, both CNSLs showed significant reduction in biomass quantification and enumeration of biofilm-entrapped cells for the strains analyzed, in biofilm formation and preformed biofilms (p < 0.05). In biofilm inhibition assay, the t-CNSL and n-CNSL showed reduction in biomass and CFU number for all bacteria, except in cell viability of S. parasanguinis treated with t-CNSL (p > 0.05). Indeed, SEM images showed a reduction in the amount of biomass, bacterial cells and changes in cellular morphology of S. mutans. CONCLUSION: In conclusion, both substances showed effective antibacterial and antibiofilm activity against the strains used in the study, except in viability of S. parasanguinis cells treated with t-CNSL.

Clinically relevant outcomes in dental clinical trials: challenges and proposals.

The impact of clinical trials on patient care depends on the outcomes that they evaluate. In Dentistry, many trials use outcomes that are important to clinicians, but not to the patients. Thus, the aim of the present manuscript is to present an overview of the limitations, challenges, and proposals on the use of clinically relevant outcomes (CRO) in dental trials. Clinically relevant outcomes are variables that directly measure how the patient feels, functions, or survives. Some CROs, such as tooth loss, implant failure, and restorations failure require many years to occur and the number of events is low. The adoption of these variables as primary outcomes results in challenges for the researchers, such as use of large sample sizes and long follow-up periods. Surrogate outcomes, such as biomarkers, radiographic measurements and indexes, are frequently used to replace CROs. However, they present many limitations, since the effect of the treatment on a surrogate does not necessarily reflect a change in the clinical outcome. Some proposals for the adoption of CROs are presented, such as the development of core outcome sets within each dental specialties and the organization of multi-center clinical trials.

Two-year clinical evaluation of a proanthocyanidins-based primer in non-carious cervical lesions: A double-blind randomized clinical trial.

OBJECTIVES: This double-blind randomized clinical trial evaluated the influence of pre-treatment with proanthocyanidins (PA) from grape seed extract on the clinical behavior of a simplified etch-and-rinse adhesive placed in non-carious cervical lesions (NCCLs) over 6- and 24-months. MATERIALS AND METHODS: A total of 135 restorations were randomly inserted in 45 subjects. The NCCLs were etched with 37 % phosphoric acid for 15 s and distributed into 3 groups: Control (PA0) - adhesive ExciTE F applied as per the manufacturer's recommendations; PA2 and PA5 groups - 2 wt% and 5 wt% PA solution, respectively, were applied for 60 s and washed for 30 s prior to application of the adhesive. The resin composite was placed incrementally and light-cured. The restorations were evaluated at baseline, 6 months (6 m) and 24 months (24 m) using both the FDI and USPHS criteria. Statistical analyses were carried out using Friedman repeated-measures analysis of variance by rank and the Wilcoxon test (α = 0.05). RESULTS: The retention rates were 98 % (PA0), 98 % (PA2) and 83 % (PA5) after 6 m and 93 % (PA0), 89 % (PA2) and 70 % (PA5) after 24 m. Only PA5 resulted in a significant lower retention rate at 6 m and at 24 m compared with that of baseline (p = 0.03). All groups resulted in a significantly worse marginal adaptation and marginal staining for the FDI criteria when the baseline vs. the 24 m recall data were compared. These differences were considered clinically acceptable under the FDI criteria. CONCLUSIONS: The application of PA as a primer did not result in clinical advantages after 24 m of clinical service, regardless of the concentration used. CLINICAL RELEVANCE: It has been reported that PA, a collagen crosslinking agent, increases the durability of the dentin-resin interface. However, no effects were found clinically after 24 months.

Influence of the degree of conversion and Bis-GMA residues of bulk fill resins on tissue toxicity in an subcutaneous model in rats.

AIM: To analyse the influence of the degree of conversion (DC) and light curing residues of different bulk fills (BFs) composites on the inflammatory profile in the subcutaneous tissue of rats. MATERIALS AND METHODS: Resin disks of BF-resins and their active conventional resins (CR; 3M®, Ivoclar®, and Kerr®) were light-cured at 2 mm (BF-superficial) and 4 mm (BF-deep) thicknesses and analyzed by infrared spectroscopy (FTIR; n = 3/group; DC and light curing residues). Then, the disks were implanted in four quadrants in the subcutaneous tissue of Wistar rats (sham, CR, BF-superficial and RF-deep), and after 7, 14, and 28 days, the animals (n = 6/day) were euthanized for histological analysis of the intensity of the inflammatory process (scores 0-3). Kruskal-Wallis/Dunn and ANOVA/Bonferroni tests were used (p < 0.05, Graph Pad Prism 5.0). RESULTS: The DC of CR 3M® did not differ significantly compared to BF-superficial and BF-deep resins (p = 0.235). The Ivoclar® and Kerr® resins showed a higher DC with CR and BF-superficial compared to the BF-deep (p = 0.005 and p = 0.011, rctively). Kerr® resins showed a higher Bis-GMA/UDMA ratio, especially in BF-deep resin (p < 0.05). 3M® and Ivoclar resins did not show high inflammation scores, but for Kerr® BF resins (superficial and deep), the inflammatory process was significantly higher than that in the CR and sham quadrants (p = 0.031). CONCLUSION: The tissue inflammatory response after resin inoculation depends on the DC and light curing residues of Bis-GMA.

Ethanol as Dentin Pretreatment on the Bonding Performance of a Two-Step Etch-and-Rinse Adhesive: An In Vivo Study.

OBJECTIVE: The aim of this study was to evaluate the use of 70 vol.% ethanol as a dentin pretreatment on the bond strength (BS) of a two-step etch-and-rinse adhesive. MATERIALS AND METHODS: Resin composite Class I restorations were clinically bonded to acid-etched dentin of human sound third molars using Adper Single Bond 2 (SB, 3M ESPE) and randomly divided into two major groups: dentin saturated with water (control) or 70 vol.% ethanol (ethanol). The teeth were divided into two subgroups: immediately extracted and tested after 24 hours and extraction after 18 months. Bonded teeth (Adper SB 2) were cut into resin-dentin sticks that were tested by microtensile BS, and the failure mode was thereafter evaluated. STATISTICAL ANALYSIS: Data were statistically analyzed using two-way analysis of variance and Holm-Sidak post hoc test (α = 0.05). Additional bonded resin-dentin slabs from each group were examined under light microscopy (LM) using the Masson's trichrome staining technique. RESULTS: The lowest BS was obtained by ethanol pretreated dentin after aging, while other groups presented similar BS. The LM analysis showed the presence of resin-sparse collagen fibrils in groups examined immediately (24 hours) and the presence of several gaps due to collagen degradation at the interfaces of ethanol pretreated aged specimens (18 months). CONCLUSION: The use of 70 vol.% ethanol in dentin before the application of a two-step etch-and-rinse adhesive should be avoided once it resulted in a significant drop on the BS.

Two-year clinical evaluation of proanthocyanidins added to a two-step etch-and-rinse adhesive.

OBJECTIVE: To compare the clinical behavior of Proanthocyanidins (PA)-free and PA-containing two-step etch-and-rinse adhesive used underneath resin composite restorations in non-carious cervical lesions (NCCLs) over a 6- (6 M) and 24-month (24 M) period. METHODS: 135 restorations were randomly placed in 45 subjects. The NCCLs were conditioned (37% phosphoric acid for 15 s) and distributed into 3 groups: Control (EX0) - ExciTE F (Ivoclar Vivadent) adhesive applied following the manufacturer's recommendations; EX2 and EX5 - 2 wt% and 5 wt% of PA were added to ExciTE F, respectively, and applied as in EX0. Resin composite was placed incrementally and light-cured. The restorations were evaluated at baseline, 6 M and 24 M, using FDI and USPHS criteria. Statistical analyses were performed using Friedman and Wilcoxon tests (α = 0.05). RESULTS: The retention rates were 98% (95% confidence interval 88-99%) for EX0, 92% (80-97%) for EX2; and 85% (72-93%) for EX5 at 6 M. A significant difference was found only for EX5 at 6 M when compared with the respective baseline findings (p = 0.03) and when compared with EX0 and EX2 (p = 0.001) at 6 M. After 24 M, the retention rates were 98% (88-99%) for EX0, 73% (59-84%) for EX2, and 71% (56-82%) for EX5. Only EX0 did not result in significant difference in retention rate at 24 M when compared with baseline but showed a significant higher retention rate when compared with those of EX2 and EX5 (p = 0.001). CONCLUSION: Adding proanthocyanidins to the adhesive solution jeopardized the retention of composite resins restorations in non-carious cervical lesions after 24 months. CLINICAL RELEVANCE: In spite of being user-friendlier than when used separately, the incorporation of proanthocyanidins into the adhesive solution impairs the longevity of composite restorations.

Deep occlusal carious lesions clinical management by Brazilian dentists: a nationwide e-survey / Manejo clínico de lesões cariosas oclusais profundas por cirurgiões-dentistas brasileiros: uma pesquisa eletrônica nacional

Objective: To investigate the clinical management of deep occlusal carious lesions in permanent teeth by Brazilian dentists. Material and Methods: This cross-sectional study included a sample of 732 Brazilian dentists who responded to an electronic questionnaire composed of 20 questions addressing socio-demographic information, training and professional activity characteristics, and clinical management of deep carious lesions. Descriptive analysis was performed, considering relative and absolute frequencies and 95% confidence intervals. The association between the dentists' variables of interest (age group, type of higher education institution, years in practice, highest academic degree completed and main sector of professional activity) and the mean number of incorrect answers regarding deep carious lesions management was analyzed by Analysis of Variance (ANOVA), followed by the Bonferroni post-test (p<0.005). Results: Stepwise removal was the strategy pointed out by most dentists (42.8%). However, 16% of the dentists selected nonselective carious tissue removal. Furthermore, 45.6% of the dentists disagreed with maintaining carious tissue over the pulp in deep lesions with a risk of pulpal exposure. When using instruments to remove carious dentine, 17% of the dentists chose a diamond burn while 13% preferred tungsten carbide burs. Dentists who graduated from public institutions had a lower mean of non-conservative decisions than those from private institutions. Dentists with master's or doctoral degrees were more conservative, as well as dentists from public service compared to those from the private sector. Conclusion: The dissemination of conservative approaches in the management of deep carious lesions needs to be strengthened and increasingly based on updated scientific literature.(AU)

Objetivo: Investigar o manejo clínico de lesões cariosas oclusais profundas em dentes permanentes por cirurgiões-dentistas brasileiros. Material e Métodos: Este estudo transversal incluiu uma amostra de 732 dentistas brasileiros que responderam a um questionário eletrônico composto por 20 questões abordando informações sociodemográficas, formação, características da atividade profissional e manejo clínico de lesões cariosas profundas. Foi realizada análise descritiva, considerando frequências relativas e absolutas, e intervalos de confiança de 95%. A associação entre as variáveis de interesse (faixa etária, tipo de instituição de ensino superior, anos de prática, maior titulação acadêmica concluída e principal setor de atividade profissional) dos cirurgiões-dentistas e a média de acertos no manejo de lesões cariosas profundas foi analisada pela Análise de Variância (ANOVA), seguida do pós-teste de Bonferroni (p<0,005). Resultados: A remoção seletiva foi a estratégia apontada pela maioria dos cirurgiões-dentistas (42,8%). No entanto, 16% dos dentistas selecionaram a remoção não seletiva do tecido cariado. Além disso, 45,6% dos dentistas discordaram da manutenção de tecido cariado sobre a polpa em lesões profundas com risco de exposição pulpar. Ao usar instrumentos para remover a dentina cariada, 17% dos dentistas escolheram uma broca diamantada, enquanto 13% preferiram brocas de carboneto de tungstênio. Cirurgiões-dentistas formados em instituições públicas apresentaram menor média de decisões não conservadoras do que os de instituições privadas. Os cirurgiões-dentistas com mestrado ou doutorado foram mais conservadores, assim como os cirurgiões-dentistas do serviço público em relação aos do setor privado. Conclusão: A disseminação de abordagens conservadoras no manejo de lesões cariosas profundas precisa ser fortalecida e cada vez mais baseada em literatura científica atualizada (AU)

Dual-cured adhesive system improves adhesive properties of dentin cavities restored with a bulk-fill resin composite

Aim: To evaluate the impact of a dual-cured adhesive system on the in situ degree of conversion (DC), bond strength (BS) and failure mode (FM) of adhesive interfaces in dentin cavities restored with a bulk-fill resin composite. Methods: 4-mm-deep dentin cavities with a 3.1 C-factor were created in 68 bovine incisors (n = 17 per group). The lightcured (Scotchbond™ Universal) or the dual-cured (Adper™ Scotchbond™ Multi-purpose Plus) adhesive system was applied to the cavities, which were then restored with a bulkfill resin composite (Filtek™ Bulk Fill). In situ DC analysis was performed by means of micro Raman spectroscopy at the top and bottom interfaces. Push-out BS was measured in a universal testing machine after 24-h or 6-month water storage. FM was determined with a stereomicroscope. Data of in situ DC and BS were analyzed by two-way analysis of variance (ANOVA) and Tukey test (p<0.05), while the FM was analyzed descriptively. Results: The groups that received the dual-cured adhesive system showed statistically higher in situ DC and BS than those that received the light-cured adhesive system. Cohesive failure mode was the most frequent in all conditions. Conclusion: In situ DC and BS were influenced by the curing strategies of the adhesive systems with better performance of the dual-cured material

2-year Clinical evaluation of sodium hypochlorite treatment in the restoration of non-carious cervical lesions: a pilot study.

This pilot study evaluated the effect of removing acid-etch-exposed dentin collagen on the clinical performance of composite restorations of noncarious cervical lesions placed using 2 different adhesive systems. Fifty-six restorations were placed in 14 subjects, each subject receiving at least 4 restorations. No cavity preparation or mechanical retention form was used. The variables tested were: 1) dentin treatment prior to application of the adhesive (acid-etch only vs acid-etch and collagen removal) and 2) type of adhesive (acetone- vs ethanol-based). For the acid-etch only groups, enamel and dentin were etched with 37% phosphoric acid for 15 seconds, rinsed and blot dried. Prime & Bond 2.1 (Dentsply Caulk) or Single Bond (3M ESPE) was applied and light-cured according to the manufacturer's instructions. For the acid-etch and collagen removal groups, the enamel and dentin were etched and rinsed in the same manner and a 10% sodium hypochlorite (NaOCl) solution was applied for 60 seconds and rinsed before adhesive application. Filtek Z-250 (3M ESPE) was applied to all specimens and light-cured according to the manufacturer's instructions, and the restorations were finished and polished immediately. The restorations were evaluated for pre- and post-operative sensitivity, retention, marginal staining and secondary caries at baseline, 12 and 24 months after placement, using modified USPHS criteria. Data were analyzed using the Kruskal-Wallis and Wilcoxon statistical tests (p=0.05). At 24 months, the retention rates for Prime & Bond 2.1 with and without NaOCl pretreatment were 80% and 63%, respectively. The corresponding retention rates for Single Bond were 70% and 90%. Marginal staining was minimal. Statistical analyses revealed no significant differences at any time interval between groups for retention or marginal staining. No post-operative sensitivity or secondary caries was detected during the study.

Clinically relevant outcomes in dental clinical trials: challenges and proposals

Abstract The impact of clinical trials on patient care depends on the outcomes that they evaluate. In Dentistry, many trials use outcomes that are important to clinicians, but not to the patients. Thus, the aim of the present manuscript is to present an overview of the limitations, challenges, and proposals on the use of clinically relevant outcomes (CRO) in dental trials. Clinically relevant outcomes are variables that directly measure how the patient feels, functions, or survives. Some CROs, such as tooth loss, implant failure, and restorations failure require many years to occur and the number of events is low. The adoption of these variables as primary outcomes results in challenges for the researchers, such as use of large sample sizes and long follow-up periods. Surrogate outcomes, such as biomarkers, radiographic measurements and indexes, are frequently used to replace CROs. However, they present many limitations, since the effect of the treatment on a surrogate does not necessarily reflect a change in the clinical outcome. Some proposals for the adoption of CROs are presented, such as the development of core outcome sets within each dental specialties and the organization of multi-center clinical trials.

Different Concentrations of Ethanol as Dentin Pre-treatment to Bonding of an Etch-and-rinse Adhesive / Diferentes Concentrações de Etanol como Pré-Tratamento da Dentina na adesão de um Adesivo Convencional

Objective: to evaluate the bond strength (BS) to dentin pre-treated with ethanol in single application for 20 s after etching and before application of a two-step etch-and-rinse adhesive and to analyze the morphological features at the resin-dentin interface. Methods: twenty four third molars were collected and randomly assigned into four groups (n=5) according to the ethanol concentration: control (traditional water-wet technique), 50vol%, 70vol% and 100vol%. In experimental groups, ethanol was applied for 20 s and gently air-dried for 5 s. Bonding procedures were performed and resin composite was built up incrementally. Bonded teeth were sectioned into 0.8mm2 sticks on average. These specimens were submitted to microtensile bond strength test (µTBS). One-way ANOVA and post hoc Tukey's test were applied to analyze statistical data (α=0 05). Light microscopy (LM) assisted by Masson's trichrome staining was used to observe the features of resin/dentin interfaces. Results: control BS was not different from ethanol 50vol% (p>0.05). However, the pre-treatment using ethanol 70vol% and 100vol% showed increase on BS (p<0.001 and p=0.003 respectively) with no difference between these two groups. LM Showed a discrete decrease in denuded collagen fibrils to teeth treated with 70vol% and 100vol%. Conclusion: the pre-treatment of dentin using ethanol may increase the initial BS of resin/dentin interface when applied using 70vol% or 100vol% ethanol. Ethanol 70vol% is also able to decrease the thickness of the resin-sparse collagen fibrils.

Objetivo: avaliar a resistência de união (RU) à dentina pré-tratada com etanol em aplicação única por 20 s após condicionamento e antes da aplicação de um adesivo convencional de dois passos e analisar as características morfológicas na interface resina-dentina. Métodos: vinte e quatro terceiros molares foram coletados e distribuídos aleatoriamente em quatro grupos (n = 5) de acordo com a concentração de etanol: controle (técnica tradicional - úmida), 50%, 70% e 100%. Em grupos experimentais, o etanol foi aplicado por 20 s e gentilmente seco ao ar por 5 s. Procedimentos de colagem foram realizados e a restauração em resina composta foi construída de forma incremental. Os espécimes foram seccionados em palitos com média de 0,8 mm2 e submetidos ao teste de resistência à microtração (µTBS). One-way ANOVA e teste post hoc de Tukey foram aplicados para analisar os dados (α = 0,05). Microscopia ótica (MO) auxiliada pela coloração tricrômica de Masson foi usada para observar as características das interfaces resina-dentina. Resultados: a RU do controle não foi diferente do etanol a 50% (p > 0,05). No entanto, o pré-tratamento utilizando etanol a 70% e 100% apresentou aumento na RU (p < 0,001 e p = 0,003 respectivamente) sem diferença entre esses dois grupos. MO apresentou uma diminuição discreta nas fibrilas de colágeno desnudadas nos dentes tratados com 70% e 100%. Conclusão: o pré-tratamento da dentina usando etanol pode aumentar a RU inicial da interface resina-dentina quando aplicado nas concentrações de 70% ou 100%. O etanol a 70% também é capaz de diminuir a espessura das fibrilas de colágeno-resina esparsas.

Saliva contamination effects at different application steps on bond strength of total etch two-step adhesive / Efeitos da contaminação por saliva em diferentes etapas de aplicação do sistema adesivo convencional de dois passos na resistência de união de restaurações adesivas

Introduction: there are clinical situations in the management of cavities favorable to saliva contamination. Human saliva is a complex mixture of oral fluids and it has been showed that the protein content of the saliva is responsible for the decrease in adhesive bond strength when contamination has occurred. Objective: this study aimed to evaluate the effect of saliva contamination during different steps of application of adhesive system on bond strength of total etch two-step adhesive system. Methods: twenty-five extracted human molars were ground flat to expose occlusal dentin. The bonding system and composite resins were applied to the dentin after etching step under five conditions (n=5/group): G1: control group­no contamination; G2: etching/ contamination/dry/adhesive system application; G3: etching/contamination/wash/dry/adhesive system application; G4: etching/adhesive system application/contamination/wash/dry/adhesive system re-application; and G5: etching/adhesive system application/contamination/dry. Microtensile bond strength was tested after specimens were stored in distilled water at 37ºC for 24h. Data (mean values -µTBS) were analyzed by ANOVA one-way and Tukey tests (α=5%), respectively. Results: Groups G2, G3 and G4 revealed bond strength similar to the control (G1). Group G5 showed significantly lower bond strengths than other groups (p<0.001). Conclusion: the total etch two-step adhesive tolerated salivary contamination except when the contamination occurred after application of the bond and it was only removed with an air jet and adhesive system was not reapplied.

Introdução: a saliva humana é uma mistura complexa de fluidos orais e tem sido demonstrado que o conteúdo proteico da saliva é responsável pela diminuição da resistência adesiva quando ocorre contaminação. Objetivo: este estudo objetivou avaliar o efeito da contaminação salivar durante diferentes etapas de aplicação do sistema adesivo sobre a resistência de união. Métodos: vinte e cinco molares humanos extraídos foram cortados para exposição da dentina oclusal. O sistema adesivo convencional e as resinas compostas foram aplicados na dentina após a etapa de condicionamento sob cinco condições (n = 5 / grupo): G1: grupo controle - sem contaminação; G2: condicionamento ácido/contaminação/secagem/adesivo; G3: condicionamento ácido/contaminação/lavagem/secagem/adesivo; G4: condicionamento ácido/aplicação do sistema adesivo/contaminação/lavagem/secagem/reaplicação do sistema adesivo; e G5: condicionamento ácido/aplicação do sistema adesivo/contaminação/secagem. A resistência à microtração foi testada após o armazenamento das amostras em água destilada a 37ºC por 24 horas. Os dados (valores médios -µTBS) foram analisados por ANOVA unidirecional e testes de Tukey (α = 5%), respectivamente. Resultados: Os grupos G2, G3 e G4 revelaram resistência de união semelhante ao controle (G1). O grupo G5 apresentou resistência de união significativamente menor que os demais grupos (p <0,001). Conclusão: o adesivo convencional de dois passos não foi afetado pela contaminação salivar, exceto quando a contaminação ocorreu após a aplicação adesiva e foi removida apenas com jato de ar e o sistema adesivo não foi reaplicado.

Biomechanical analysis of titanium plate systems in mandibular condyle fractures: a systematized literature review.

PURPOSE: To conduct a systematized review of the literature about the main methodologies used to evaluate the biomechanical fixation systems with titanium plates in fractures of the mandibular condyle. METHODS: A systematized review of literature was performed in the electronic databases PubMed, EMBASE, LILACS and MEDLINE without restriction of the publication date. The eligibility criteria were laboratory studies involving mandibular condyle fractures, studies using titanium plates, biomechanical studies, in vitro and computational studies involving the finite element method (FEM). RESULTS: Eleven articles that met the eligibility criteria were selected, including seven articles involving in vitro studies and four studies with biomechanical analysis by using FEM. CONCLUSION: Although few articles have used the finite element method, the results of in vitro studies were similar to those found in computational studies, regarding to the stable use of two titanium miniplates.

Resistência de união de um sistema restaurador à base de silorano ao esmalte bovino / Bond strength of a Silorane-based composite to bovine enamel

O objetivo do presente estudo foi avaliar a resistência de união ao esmalte bovino de um sistema adesivo para compósitos à base de silorano, com e sem condicionamento prévio. Para isso, foram selecionados 12 incisivos bovinos com superfície de esmalte planificada e, então, divididos em dois grupos: Grupo 1 (P90) - realizado um platô em esmalte com o sistema restaurador P90; Grupo 2 (P90A) - realizado um platô com condicionamento ácido prévio à utilização do sistema adesivo, utilizando ácido fosfórico a 37% por 15s. Os espécimes (n=6) foram seccionados nos eixos "x" e "y" para obtenção de palitos para o teste de microtração com velocidade de 0,5mm/min. Os dados obtidos foram submetidos aos testes ANOVA One-way e Tukey. Os testes de microtração mostraram um aumento na resistência de união, quando utilizado o condicionamento ácido prévio ao sistema adesivo adotado no estudo (p<0,05). Concluiu-se que o condicionamento prévio com ácido fosfórico a 37% aumentou a resistência de união do sistema restaurador à base de silorano ao esmalte bovino.

The purpose of this study was to evaluate the bond strength produced by a Silorane-based restorative system to enamel with or without prior acid etching. Twelve bovine incisors were selected. Then, the enamel was planned. The teeth were divided into two groups: Group 1 - a plateau was built in the enamel planned with P90 system (P90); Group 2 - a plateau was built in the enamel with prior etching using 37% phosphoric acid for 15s (P90A). Specimens (n=6) were sectioned in enamel/composite sticks to microtensile testing. The cross-sectional area of the sticks was measured. Beams were pulled until failure and bond strength was calculated. Data were statistically analyzed using ANOVA One-way and Tukey (p=0,05). Microtensile bond strength showed higher values to group 2 (P90A), that used prior etching to the adhesive system tested in the study. In conclusion prior etching with phosphoric acid increased microtensile bond strength values of the Silorane-based composite on bovine enamel.

Biomechanical analysis of titanium plate systems in mandibular condyle fractures: a systematized literature review / Análise biomecânica de sistemas de placas de titânio em fraturas de côndilo mandibular: uma revisão sistematizada da literatura

PURPOSE: To conduct a systematized review of the literature about the main methodologies used to evaluate the biomechanical fixation systems with titanium plates in fractures of the mandibular condyle. METHODS: A systematized review of literature was performed in the electronic databases PubMed, EMBASE, LILACS and MEDLINE without restriction of the publication date. The eligibility criteria were laboratory studies involving mandibular condyle fractures, studies using titanium plates, biomechanical studies, in vitro and computational studies involving the finite element method (FEM). RESULTS: Eleven articles that met the eligibility criteria were selected, including seven articles involving in vitro studies and four studies with biomechanical analysis by using FEM. CONCLUSION: Although few articles have used the finite element method, the results of in vitro studies were similar to those found in computational studies, regarding to the stable use of two titanium miniplates.

OBJETIVO: Realizar uma revisão sistematizada da literatura sobre as principais metodologias empregadas na avaliação biomecânica de sistemas de fixação com placas de titânio em fraturas de côndilo mandibular. MÉTODOS: Foi realizada uma revisão sistematizada da literatura nas bases de dados eletrônicas PubMed, EMBASE, LILACS e MEDLINE sem restrição quanto à data de publicação. Os critérios de elegibilidade foram estudos laboratoriais envolvendo fraturas de côndilo mandibular, estudos utilizando placas de titânio, estudos biomecânicos, estudos in vitro e estudos computacionais envolvendo o método de elementos finitos (MEF). RESULTADOS: Foram selecionados 11 artigos que se enquadraram nos critérios de elegibilidade, incluindo sete artigos envolvendo estudos in vitro e quatro utilizando análise biomecânica através do MEF. CONCLUSÃO: Embora poucos artigos tenham utilizado o método de elementos finitos, os resultados das pesquisas in vitro assemelham-se aos encontrados nos estudos computacionais, com relação ao uso estável de duas miniplacas de titânio.

Efficacy of smear layer removal by cavity cleaning solutions: an atomic force microscopy study / Eficácia da remoção da lama dentinária por soluções de limpeza cavitária: estudo de microscopia de força atômica

PURPOSE: To evaluate the efficacy of smear layer removal by cavity cleaning agents by the use of atomic force microscopy (AFM). METHODS: Five intact human third molars were sectioned in the coronal portion to obtain dentin disks, which were ground with 600-grit abrasive paper for 10 s. Serial longitudinal sections were made perpendicular to each other to create four specimens, from each tooth. The specimens were divided into four treatment groups: GI, 2 percent chlorhexidine; GII, calcium hydroxide solution; GIII, 1.23 percent fluoride solution; and GIV, 37 percent phosphoric acid. The solutions were applied with a brush for 60 s, with the exception of the 37 percent phosphoric acid, which was applied for 15 s and rinsed with distilled water for 60 s. The specimens were examined by AFM. RESULTS: All of the specimens in GI and GII showed 100 percent of the dentin tubules obliterated by the smear layer. However, all of the specimens in GIII and GIV showed 0 percent of the dentin tubules obliterated by the smear layer. CONCLUSION: The 1.23 percent fluoride solution was effective in removing the smear layer and can be used as a cavity cleanser.

OBJETIVO: Avaliar a eficácia da remoção de lama dentinária por agentes de limpeza cavitária através da análise de microscopia de força atômica (MFA). METODOLOGIA: Cinco terceiros molares humanos hígidos foram seccionados transversalmente na porção coronária, obtendo discos de dentina de 2 mm, que foram desgastados com lixas de granulação 600, por 10 s.Foram feitos cortes seriados longitudinais e perpendiculares entre si, obtendo-se quarto espécimes de cada dente. Os espécimes foram divididos em 4 grupos: GI- clorexidina a 2 por cento; GII- água de hidróxido de cálcio; GIII- solução fluoretada a 1,23 por cento; GIV - ácido fosfórico 37 por cento. As soluções foram aplicadas com pincel por 60 s, com exceção do ácido fosfórico que foi aplicado por 15 s e lavado com água destilada pelo mesmo tempo. Os espécimes foram analisados por MFA. RESULTADOS: Todos os espécimes de GI e GII apresentaram 100 por cento dos túbulos dentinários obliterados por lama dentinária. Os espécimes de GIII e GIV apresentaram 0 por cento dos túbulos obliterados por lama dentinária. CONCLUSÃO: A solução de fluoretada a 1,23 por cento foi eficiente na remoção de lama dentinária, podendo ser empregada na limpeza de cavidades.

Resistência de união de pinos de fibra de vidro à dentina em diferentes regiões do canal radicular / Bond strength of glass fiber posts to dentin in different regions of the root canal

OBJETIVO: Avaliar a resistência de união da interface adesiva de pinos de fibra de vidro (Reforpost nº 3 - Angelus) e dentina radicular. MÉTODOS: Vinte e quatro raízes de dentes humanos foram tratadas endodonticamente e desobstruídas até uma profundidade de 9mm e o pino cimentado com um dos três sistemas de fixação descritos a seguir (n = 8): Grupo 1 - sistema Single Bond 2 (3M ESPE, St. Paul, MN, EUA) / RelyX ARC (3M ESPE, St. Paul, MN, EUA); Grupo 2 - sistema ED Primer/Panavia 21 (Kuraray Medical Inc. Kurashiki, Japão); Grupo 3 - cimento RelyX Unicem (3M ESPE/AG. Seefeld, Alemanha). As raízes foram seccionadas em três porções correspondentes aos terços cervical, médio e apical. Os espécimes foram submetidos aos testes de push-out e os valores de resistência de união à análise de variância (ANOVA) e ao teste de Tukey (p< 0,05). RESULTADOS: Somente o Grupo 2 apresentou diferença estatística em relação aos terços, tendo o apical apresentado menor média. Para o terço cervical, o Grupo 3 apresentou maiores valores de resistência de união que o Grupo 2, tendo sido Grupo 1 estatisticamente semelhante aos outros dois materiais. Para os terços médio e apical, Grupo 2 apresentou resistência de união menor que Grupo 1 e Grupo 3, sendo estes estatisticamente iguais entre si. CONCLUSÃO: Os cimentos de presa dual (RelyX ARC, 3M ESPE, St. Paul, MN, EUA e RelyX Unicem, 3M ESPE, St. Paul, MN, EUA) promoveram maior resistência de união entre o pino endodôntico e as paredes do canal radicular do que o cimento quimicamente ativado (Panavia 21, Kuraray Medical Inc., Kurashiki, Japão).

OBJECTIVE: This study assessed the bond strength of the adhesive interface of fiber glass posts (Reforpost nº 3 - Angelus) to root dentin. METHODS: Twenty-four roots of human teeth were treated endodontically and drilled to a depth of 9mm. Posts were cemented using one of the following three systems (n = 8): group 1 (G1) - Single Bond 2 system (3M ESPE, St. Paul, MN, EUA) / RelyX ARC (3M ESPE, St. Paul, MN, EUA); group 2 (G2) ED Primer (Kuraray Medical Inc. Kurashiki, Japan) / Panavia 21 (Kuraray Medical Inc. Kurashiki, Japan) system; and group 3 (G3) RelyX Unicem (3M ESPE/AG. Seefeld, Germany) cement. The roots were sectioned into three parts corresponding to the coronal, middle and apical thirds. The specimens were submitted to the push-out test. Bond strength values were submitted to analysis of variance (ANOVA) and the Tukey's test (p< 0.05). RESULTS: Only G2 presented statistically significant differences among the three regions of the canal with the apical third presenting the lowest mean bond strength. In relation to the coronal third, G3 presented higher bond strengths than G2. G1 was statistically equal to the other two materials. Regarding the middle and apical thirds, the mean bond strength of G2 was significantly lower than those of G2 and G3, these two being statistically equal. CONCLUSION: The dual-cure cements (RelyX ARC, 3M ESPE, St. Paul, MN, EUA and RelyX Unicem, 3M ESPE, St. Paul, MN, EUA) promoted higher bond strengths between the endodontic post and root dentin than the self-cure cement (Panavia 21, Kuraray Medical Inc., Kurashiki, Japan).