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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.

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PURPOSE: This study aimed to evaluate whether discriminatory episodes occurring in the university environment were associated with dental students' self-perceived overall quality of life and assess the cumulative effect of perceived discriminatory experiences on the overall quality of life. METHODS: In this cross-sectional study, all students enrolled in three Brazilian dental schools were invited to participate in a survey between August and October 2019. The outcome was students' self-perceived quality of life, measured through the overall quality of life item of the World Health Organization-Quality of Life Abbreviated Version (WHOQOL-BREF). Descriptive, bivariate, and multivariable logistic regression analyses (95% confidence intervals and α of 5%) were conducted using RStudio software. RESULTS: The sample was composed of 732 students (70.2% response rate). The great part was female (66.9%), white or yellow skin color (67.9%), and were children of highly educated mothers. About 68% of the students reported having experienced at least one of the seven discriminatory experiences presented in the questionnaire and 18.1% reported neutral or negative quality of life. In multivariable analyses, it was estimated that students who experienced at least one episode of discrimination were 2.54 times (95% CI: 1.47-4.34) more likely to report worse quality of life than their counterparts who reported no experience of discrimination. There was also a 25% (95% CI: 1.10-1.42) increase in the odds of reporting poorer quality of life for each additional discriminatory experience reported. CONCLUSION: Reporting at least one discriminatory situation in the academic environment was associated with worse quality of life among dental students, and a cumulative effect was also noted.

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Os sistemas adesivos estão diretamente envolvidos nos procedimentos mais corriqueiros da prática clínica odontológica, o que torna o seu conhecimentoindispensável para os profissionais. O objetivo do presente estudo foi avaliar o perfil de conhecimento sobre sistemas adesivos e verificar os fatores que influenciam nesse desfecho, com ênfase na formação profissional. A coleta de dados foi realizada pormeio de um questionário levando em consideração: I. Perfil do profissional; II. Conhecimento, uso e preferências sobre os sistemas adesivos. A amostra foi composta por 501 cirurgiões-dentistas brasileiros e os dados foram analisados no programa Sigma Stat5.0 (p<0,05). O percentual mínimo de acertos das questões considerado adequado foi definido como 80%. Os resultados mostraram que apenas 46,3% dos profissionais demonstraram conhecimento adequado sobre o assunto. Além disso, verificou-se associação estatisticamente significativa entre o baixo nível de acertos e profissionais com preferência por sistemas adesivos simplificados (p=0,046), especialistas em ortodontia [OR=0,24 (0,08-0,67)] e cirurgiões-dentistas graduados em instituições privadas [OR=1,58 (1,03-2,42)]. Esse cenário alerta para a necessidade iminente de sanar essa fragilidade por meio de melhorias nas matrizes curriculares, além da educação continuada de docentes e constante atualização dos profissionais (AU).

Los sistemas adhesivos están directamente involucrados en los procedimientos más comunes de la práctica clínica dental, lo que hace que su conocimiento sea fundamental para los profesionales. El objetivo del presente estudio fue evaluar el perfil de conocimiento sobre sistemas adhesivos y verificar los factores que influyen en ese resultado, con énfasis en la formación profesional. La recolección de datos se realizó a través de un cuestionario teniendo en cuenta: I. Perfil del profesional; II. Conocimiento,uso y preferencias sobre los sistemas adhesivos. La muestra estuvo compuesta por 501 dentistas brasileños y los datos fueron analizados mediante el programa Sigma Stat 5.0 (p<0,05). El porcentaje mínimo de respuestas correctas a las preguntas considerado adecuado se definió en el 80%. Los resultados mostraron que sólo el 46,3% de los profesionales demostraron conocimientos adecuados sobre el tema. Además, hubo una asociación estadísticamente significativa entre el bajo nivel de aciertos y los profesionalescon preferencia por los sistemas adhesivos simplificados (p=0,046), especialistas en ortodoncia [OR=0,24 (0,08-0,67)] y odontólogos egresados de instituciones privadas [OR=1,58 (1,03-2,42)]. Este escenario advierte de la inminente necesidad de subsanar esta debilidad a través de mejoras en las matrices curriculares, además de la formación continua de los docentes y la constante actualización de los profesionales (AU).

Dental adhesive systems are directly involved in common procedures of clinical dentistry, which makes knowledge about this topic indispensable for professionals. The objectives of the current study are to analyze the knowledge profile of dental professionals about dental adhesive systems and verify factors that influence this closure, with emphasis on professional education. The data was collected using a list of questions that consider: I) Professional profile and II) Knowledge, use, and preferences of adhesive systems. The sample considers 501 Brazilian dentists and the data was analyzed using the software Sigma Stat 5.0 (p<0.05). The minimum percentual of correct questions considered adequate was defined as 80%. The results show that only 46.3% of the professionals demonstrated satisfactory knowledge on the subject. In addition, it verified relevant statistical association between low level of correct questions and professionals with preferences for simplified adhesive systems (p=0.046), orthodontic specialists [OR=0.24 (0.08­0.67)], and dentists with private education degrees [OR=1.58 (1.03­2.42)]. This context indicates the imminent necessity to resolve this weakness through improvements in the educational curriculum, as well as continuing education of faculty and constant updating of professionals (AU).

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OBJECTIVES: To develop a 3D-printed, microparticulate hydrogel supplemented with dentin matrix molecules (DMM) as a novel regenerative strategy for dental pulp capping. MATERIALS AND METHODS: Gelatin methacryloyl microgels (7% w/v) mixed with varying concentrations of DMM were printed using a digital light projection 3D printer and lyophilized for 2 days. The release profile of the DMM-loaded microgels was measured using a bicinchoninic acid assay. Next, dental pulp exposure defects were created in maxillary first molars of Wistar rats. The exposures were randomly capped with (1) inert material - negative control, (2) microgels, (3) microgels + DMM 500 µg/ml, (4) microgels + DMM 1000 µg/ml, (5) microgels + platelet-derived growth factor (PDGF 10 ng/ml), or (6) MTA (n = 15/group). After 4 weeks, animals were euthanized, and treated molars were harvested and then processed to evaluate hard tissue deposition, pulp tissue organization, and blood vessel density. RESULTS: All the specimens from groups treated with microgel + 500 µg/ml, microgel + 1000 µg/ml, microgel + PDGF, and MTA showed the formation of organized pulp tissue, tertiary dentin, newly formed tubular and atubular dentin, and new blood vessel formation. Dentin bridge formation was greater and pulp necrosis was less in the microgel + DMM groups compared to MTA. CONCLUSIONS: The 3D-printed photocurable microgels doped with DMM exhibited favorable cellular and inflammatory pulp responses, and significantly more tertiary dentin deposition. CLINICAL RELEVANCE: 3D-printed microgel with DMM is a promising biomaterial for dentin and dental pulp regeneration in pulp capping procedures.

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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)

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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

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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.

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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.

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To evaluate i) the inhibitory and bactericidal activity of cashew nut shell liquid (CNSL) and its isolated compounds (anacardic acid and cardol) against oral bacteria; ii) the biofilm formation inhibition, resin-dentin bond strength and physicochemical properties of a dental adhesive incorporated with these substances. The antibacterial effect of CNSL, anacardic acid, and cardol were assessed by determining the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations. Effect in inhibiting biofilm formation of the adhesive incorporated with the substances (15 µg/ml) against a mixed-species biofilm of Streptococcus mutans and Candida Albicans and was determined by direct contact test. Additional Analysis included microtensile bond strength (µTBS) test, elastic modulus (EM), flexural strength (FS), degree of conversion (DC), water sorption (WS) and solubility (SL). The data were submitted to statistical analysis by one-way ANOVA and Tukey's test (p < 0.05). CNSL, anacardic acid and cardol showed antibacterial activity for all strains tested, with MIC and MBC values ranging from 3.12 to 25 µg/ml. There was no growth of colonies forming units in the adhesives incorporated with the substances. EM increased in the adhesive incorporated with anacardic acid, decreased after incorporation of cardol and it was not affected by incorporation of CNSL. The substances tested showed no effect in FS, DC, WS, SL and µTBS. In conclusion, the CNSL, anacardic acid and cardol showed antibacterial effects against oral bacteria and, the incorporation of substances did not reduce the performance of the adhesive.

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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.

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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.

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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.

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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.

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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.

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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.

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The aim of this study was to evaluate the degree of conversion (DC), flexural strength (FS), and shear bond strength (SBS) of ceramic brackets bonded to enamel with experimental self-adhesive orthodontic composites. Functional monomers 10-methacryloyloxy-decyl-dihydrogen-phosphate (MDP) and glycerol-dimethacrylate-phosphate (GDMA-P) were used in experimental composites. They were compared to the same composite without an acidic monomer (negative control) and with enamel acid-etching prior to adhesive application (positive control). DC was evaluated by Raman micro-spectroscopy. Flexural three-point bending testing was performed in a universal testing machine. Ceramic brackets were bonded to bovine enamel and SBS was evaluated before and after 2000 thermal-cycles. Fracture patterns were surveyed with manual removal with specific pliers and analyzed by SEM. Statistics was performed using ANOVA and Tukey's test (p < 0.05). DC of the control composite was significantly higher (p < 0.001) than that of GDMA-P and MDP. FS showed no significant difference between composites (p = 0.451). Regarding adhesion, the positive control (8.47 ± 0.88 MPa) and MDP (7.07 ± 2.69 MPa) obtained higher overall results. The predominant fracture pattern of the positive control and MDP was mixed while it was adhesive for further groups. The MDP-containing orthodontic composite attained similar adhesion to a conventional three-step orthodontic bonding system, with a similar fracture pattern and mechanical properties. Nevertheless, the presence of acidic functional monomers reduced the DC.

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This study is aimed at evaluating the effects of triclosan-encapsulated halloysite nanotubes (HNT/TCN) on the physicochemical and microbiological properties of an experimental dental composite. A resin composite doped with HNT/TCN (8% w/w), a control resin composite without nanotubes (HNT/TCN-0%) and a commercial nanofilled resin (CN) were assessed for degree of conversion (DC), flexural strength (FS), flexural modulus (FM), polymerization stress (PS), dynamic thermomechanical (DMA) and thermogravimetric analysis (TGA). The antibacterial properties (M) were also evaluated using a 5-day biofilm assay (CFU/mL). Data was submitted to one-way ANOVA and Tukey tests. There was no significant statistical difference in DC, FM and RU between the tested composites (p > 0.05). The FS and CN values attained with the HNT/TCN composite were higher (p < 0.05) than those obtained with the HNT/TCN-0%. The DMA analysis showed significant differences in the TAN δ (p = 0.006) and Tg (p = 0) between the groups. TGA curves showed significant differences between the groups in terms of degradation (p = 0.046) and weight loss (p = 0.317). The addition of HNT/TCN induced higher PS, although no significant antimicrobial effect was observed (p = 0.977) between the groups for CFUs and (p = 0.557) dry weight. The incorporation of HNT/TCN showed improvements in physicochemical and mechanical properties of resin composites. Such material may represent an alternative choice for therapeutic restorative treatments, although no significance was found in terms of antibacterial properties. However, it is possible that current antibacterial tests, as the one used in this laboratory study, may not be totally appropriate for the evaluation of resin composites, unless accompanied with aging protocols (e.g., thermocycling and load cycling) that allow the release of therapeutic agents incorporated in such materials.

RESUMO

Degradation of the hybrid layer created in dentin by dentin adhesives is caused by enzyme activities present within the dentin matrix that destroy unprotected collagen fibrils. The aim of the present study was to evaluate the effect of a one-step self-etch adhesive system on dentinal matrix metalloproteinases 2 and 4 (MMP-2 and MMP-9, respectively) using in situ zymography and an enzymatic activity assay. The null hypothesis tested was that there are no differences in the activities of dentinal MMPs before and after treatment with a one-step adhesive system. The MMP-2 and MMP-9 activities in dentin treated with the one-step adhesive, Adper Easy Bond, were quantified using an enzymatic activity assay system. The MMP activities within the hybrid layer created by the one-step adhesive tested were also evaluated using in situ zymography. The enzymatic assay revealed an increase in MMP-2 and MMP-9 activities after treatment with adhesive. In situ zymography indicated that gelatinolytic activity is present within the hybrid layer created with the one-step self-etch adhesive. The host-derived gelatinases were localized within the hybrid layer and remained active after the bonding procedure. It is concluded that the one-step self-etch adhesive investigated activates endogenous MMP-2 and MMP-9 with the dentin matrix, which may cause collagen degradation over time.

Assuntos

RESUMO

AIM: The use of fluoride-releasing materials could be compromised due to aging and might also be influenced by other ordinary sources of fluoride. The aim of the present study was to investigate the aging effect on caries development around resin-modified glass ionomer cement (RMGIC) restorations and the influence of fluoride dentifrice use in this process under the oral environment. METHODS: A clinical study was performed in two phases of 14 days each. A total of 16 volunteers wore palatal devices containing dental slabs restored with either a composite resin or RMGIC, either aged or unaged by thermocycling. To simulate a clinical situation of high caries risk, the slabs were exposed to a 20% sucrose solution 10 times per day via the in situ model, where non-fluoride or a fluoride dentifrice was used. Integrated demineralization was determined by cross-sectional microhardness at both margins of the restoration: enamel and dentin. RESULTS: For enamel, higher demineralization around the composite restorations was observed, regardless of dentifrice or aging. For dentin, higher demineralization was observed around the aged composite restorations regardless of the dentifrice type used. CONCLUSIONS: The RMGIC restorations provided more enhanced protection against secondary caries for dentin under aging, and the fluoride dentifrice used in this condition had either no clinically relevance or only a minimal effect.

Assuntos