Uso de aplicativo de inteligência artificial como fonte de informação para resolução de provas de Odontologia / Use of an artificial intelligence application as a source of information for solving Dentistry exams

Introdução: O ChatGPT® é uma ferramenta pública desenvolvida pela OpenAI que utiliza a tecnologia do modelo de linguagem GPT. Este chatbot é capaz de atender a variadas solicitações de texto. Objetivo: avaliar se o ChatGPT® é capaz de ser a única fonte de informação para resolução de provas de Odontologia. Material e métodos: consiste em um estudo transversal quantitativo analítico. Para a coleta de dados, foi elaborada uma prova fictícia constituída por questões do ENADE e de outros concursos públicos. Os participantes responderam a prova em dois momentos: T1, sem o ChatGPT® e, após 15 dias (T2), utilizando-o. A amostra foi de 30 discentes de graduação em Odontologia, divididos igualmente entre 3 grupos: 1º ao 4º semestre, 5º ao 6º semestre e 7º ao 10º semestre. Para análise de dados foram aplicadas análises estatísticas descritiva e inferencial, por meio do software SPSS, com os testes de Wilcoxon e de McNemar. Resultados: revelaram uma eficácia notável do ChatGPT® na resolução de questões discursivas, com 83,3% de taxa de acerto, enquanto os discentes deram mais respostas incorretas ou incompletas. Porém, foram observadas limitações da base de dados do ChatGPT® quanto às questões objetivas. É crucial ressaltar que, apesar de resultados promissores, a aplicação do Chat levanta questões éticas e pedagógicas. Assim, a introdução do ChatGPT® na educação preocupa quanto à validade e equidade nas avaliações, destacando a importância de encontrar equilíbrio entre a inovação tecnológica e a preservação da integridade acadêmica

Introduction: ChatGPT® is a public tool developed by OpenAI that employs the language model technology of GPT. This chatbot is capable of addressing various text-based requests. Objective: To assess whether ChatGPT® can be the sole source of information for resolving Dentistry exams. Materials and Methods: This is an analytical quantitative cross-sectional study. For data collection, a fictitious exam was created, consisting of questions from the National Student Performance Exam (ENADE) and other public competitions. Participants answered the exam at two different times: T1, without ChatGPT®, and, after 15 days (T2), using it. The sample included 30 undergraduate Dentistry students, equally divided into three groups: 1st to 4th semester, 5th to 6th semester, and 7th to 10th semester. Descriptive and inferential statistical analyses were applied using SPSS software, including the Wilcoxon and McNemar tests. Results: They revealed a notable effectiveness of ChatGPT® in resolving essay questions, with an 83.3% accuracy rate, while students provided more incorrect or incomplete answers. However, limitations of the ChatGPT® database were observed regarding objective questions. It is crucial to emphasize that, despite promising results, the application of Chat raises ethical and pedagogical questions. Therefore, the introduction of ChatGPT® in education raises concerns about the validity and fairness of assessments, underscoring the importance of finding a balance between technological innovation and the preservation of academic integrity

Anti-erosion effect of an experimental varnish on eroded dentin.

This in vitro study evaluated the effect of an experimental varnish containing 20% nano-hydroxyapatite (nHAP) associated with 5% stannous chloride (SnCl2) against erosive-abrasive wear on bovine dentin. Samples of bovine cervical dentin were pre-eroded (0.3% citric acid, pH 2.6 for 10 minutes) and randomized into 4 groups (n=10): Control group - experimental varnish without active ingredient (CG); experimental varnish containing 20% nHAP (nHG); experimental varnish containing 5% SnCl2 (24.800 ppm Sn2+) (SnG); experimental varnish containing 20% nHAP associated with 5% SnCl2 (18.300 ppm Sn2+) (nHSnG). After applying the materials, the erosive-abrasive challenges were performed for five days. Erosive dentin loss and analysis of the pattern of dentinal obliteration were performed by 3D confocal laser microscopy. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The SnG and nHSnG experimental groups presented more effectiveness in preventing erosive wear when compared to the other groups (p<0.05). There was no statistically significant difference between the SnG and nHSnG groups (p = 0.731) in tooth structure dentin loss. Regarding the amount of open dentinal tubules, the highest amount of obstructed dentinal tubules was demonstrated in SnG and nHSnG (p < 0.05) when compared to the others. Between SnG and nHSnG there was no significant difference (p = 0.952) in the amount of closed dentinal tubules in the dentin. Experimental varnishes containing 5% SnCl2 associated or not with 20% nHAP showed to be a promising strategy in preventing erosive-abrasive wear of dentin. In addition, nHSnG was able to obliterate dentinal tubules.

Clinical evaluation of surface treatment on clinical performance of non-carious sclerotic cervical lesions: 18-month follow-up.

PURPOSE: To evaluate the influence of different surface treatments on the clinical behavior of non-carious cervical sclerotic lesions (NCCLs) over an 18-month follow-up period. METHODS: 128 NCCLs from 32 volunteers were randomized into four groups (n=32): G1-control, without preoperative treatment of the dentin surface; G2, dentin conditioning with 17% ethylenediaminetetracetic acid (EDTA) for 2 minutes; G3, increase in dentin surface roughness with diamond bur and G4, increase in dentin surface roughness with diamond bur + dentin conditioning with 17% EDTA for 2 minutes. RESULTS: Differences between groups were tested using the Friedman test (α= 0.05). A questionnaire was administered to volunteers about risk factors related to NCCLs. The relationship between the questionnaire data and the clinical performance of the restorations was analyzed using the multiple logistic regression test (α= 0.05). The variables related to parafunctional habits, anxiety and/or depression were significantly related to the manifestation of postoperative sensitivity. Roughening the sclerotic dentin with a diamond bur increased postoperative sensitivity within 12 months. The presence of parafunctional habits and anxiety/depression may lead to postoperative sensitivity. CLINICAL SIGNIFICANCE: Roughening the sclerotic dentin with a diamond bur increased postoperative sensitivity within 12 months.

Perfil de componentes curriculares e docentes de Odontologia Legal e saúde coletiva de cursos de graduação em Odontologia da região norte do Brasil / Profile of curricular components and professors of Forensic Dentistry and Public Health in undergraduate dentistry courses in the northern region of Brazil

Introdução: Odontologia Legal (OL) e Saúde Coletiva (SC) contribuem na formação do cirurgião-dentista em aspectos relacionados à ética profissional, à cidadania e à atenção às necessidades de saúde da população. Objetivo: analisar o perfil de componentes curriculares e docentes de OL e SC de cursos de graduação em Odontologia. Material e método: Trata-se de um estudo transversal quantitativo desenvolvido por meio de formulário eletrônico aplicado a docentes de componentes curriculares de OL e SC de cursos da região norte do Brasil, em 2022. Para análise de dados, foi aplicada estatística descritiva e os testes Qui-quadrado e Exato de Fisher. Resultados: Quarenta docentes participaram da pesquisa, sendo 12 de instituições públicas, 27 de particulares e 1 de ambas. Deles, 10 (25%) eram de OL, 22 (55%) de SC e 8 (23%) de ambos os componentes curriculares. Todos (100%) os componentes curriculares de OL eram obrigatórios e ministrados em 1 a 3 semestres do curso, a maioria com ensino presencial (94,4%) e 50% em aulas teóricas e práticas. Os componentes curriculares de SC possuíam grande variabilidade de distribuição de períodos no curso, a maioria com carga horária de até 200 horas. Pouco mais de 40% dos docentes de OL possuíam formação específica na área. Para SC, 63% dos docentes possuíam formação específica. A oportunidade de trabalho ou de inserção em uma instituição de ensino foi o motivo mais citado pelos docentes que não possuíam formação específica na área dos componentes curriculares que ministravam. Não houve diferença estatisticamente significativa no perfil dos docentes. Conclusão: os componentes curriculares de OL não estavam alinhados às diretrizes da Associação Brasileira de Ética e Odontologia Legal e os componentes curriculares de SC seguiam as previsões das Diretrizes Nacionais Curriculares de 2002

Introduction: Forensic Dentistry (FD) and Public Health (PH) contribute to dentist's development in aspects related to professional ethics, citizenship and attention to the population health needs. Aim: to analyze the profile of FD and PH curricular components and professors in undergraduate courses of Dentistry. Material and methods: a quantitative cross-sectional study was carried out using an electronic questionnaire sent to professors who taught FD and PH in north Brazilian colleges in 2022. To data analysis, descriptive statistics, Chi-square and Fisher's exact tests were applied. Results: Forty professors participated in the survey, 12 from public institutions, 27 from private institutions and 1 from both. Of them, 10 (25%) were professors of FD, 22 (55%) of PH and 8 (23%) of both curricular components. All (100%) FD curricular components were mandatory and taught in 1 to 3 semesters of the course, most with face-to-face teaching (94.4%) and 50% with theoretical and practical classes. PH curricular components had great variability in the distribution of periods in the course, most with a workload up to 200 hours. Just over 40% of FD professors had specific training in the area. In the PH area, 63% of professors had specific training. The opportunity for work or insertion in an educational institution was the reason most cited by professors who did not have specific training in the area of the curricular components they taught. There was no statistically significant difference in the professors' profile. Conclusion: the FD curricular components were not aligned with the guidelines of the Brazilian Association of Ethics and Forensic Dentistry and the PH curricular components followed the predictions of the 2002 National Curricular Guidelines

Anti-erosion effect of an experimental varnish on eroded dentin

Abstract This in vitro study evaluated the effect of an experimental varnish containing 20% nano-hydroxyapatite (nHAP) associated with 5% stannous chloride (SnCl2) against erosive-abrasive wear on bovine dentin. Samples of bovine cervical dentin were pre-eroded (0.3% citric acid, pH 2.6 for 10 minutes) and randomized into 4 groups (n=10): Control group - experimental varnish without active ingredient (CG); experimental varnish containing 20% nHAP (nHG); experimental varnish containing 5% SnCl2 (24.800 ppm Sn2+) (SnG); experimental varnish containing 20% nHAP associated with 5% SnCl2 (18.300 ppm Sn2+) (nHSnG). After applying the materials, the erosive-abrasive challenges were performed for five days. Erosive dentin loss and analysis of the pattern of dentinal obliteration were performed by 3D confocal laser microscopy. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The SnG and nHSnG experimental groups presented more effectiveness in preventing erosive wear when compared to the other groups (p<0.05). There was no statistically significant difference between the SnG and nHSnG groups (p = 0.731) in tooth structure dentin loss. Regarding the amount of open dentinal tubules, the highest amount of obstructed dentinal tubules was demonstrated in SnG and nHSnG (p < 0.05) when compared to the others. Between SnG and nHSnG there was no significant difference (p = 0.952) in the amount of closed dentinal tubules in the dentin. Experimental varnishes containing 5% SnCl2 associated or not with 20% nHAP showed to be a promising strategy in preventing erosive-abrasive wear of dentin. In addition, nHSnG was able to obliterate dentinal tubules.

Resumo Este estudo in vitro avaliou o efeito de um verniz experimental contendo 20% de nano-hidroxiapatita (nHAP) associado a 5% de cloreto estanoso (SnCl2) contra o desgaste erosivo-abrasivo da dentina bovina. As amostras de dentina cervical bovina foram pré-erodificadas (0,3% de ácido cítrico, pH 2,6 durante 10 minutos) e aleatorizadas em 4 grupos (n=10): Grupo controle - verniz experimental sem ingrediente ativo (GC); verniz experimental contendo 20% nHAP (GnH); verniz experimental contendo 5% SnCl2 (24.800 ppm Sn2+) (GSn); verniz experimental contendo 20% nHAP associado a 5% SnCl2 (18.300 ppm Sn2+) (GnHSn). Após a aplicação dos materiais, os desafios erosivo-abrasivos foram realizados durante cinco dias. Perda de dentina erosiva e análise do padrão de obliteração dentinária foram realizadas por microscopia laser confocal 3D. Foi realizado o teste ANOVA/Bonferroni unidireccional para analisar os dados (α=0,05). Os grupos experimentais GSn e GnHSn apresentaram maior eficácia na prevenção do desgaste erosivo quando comparados com os outros grupos (p<0,05). Não houve diferença estatisticamente significativa entre os grupos GSn e GnHSn (p = 0,731) na perda de dentina da estrutura dentária. Relativamente à quantidade de túbulos dentinários abertos, a maior quantidade de túbulos dentinários obstruídos foi demonstrada em GSn e GnHSn (p < 0,05) quando comparada com os outros grupos. Entre GSn e GnHSn, não houve diferença significativa (p = 0,952) na quantidade de túbulos dentinários fechados na dentina. Os vernizes experimentais contendo 5% de SnCl2 associados ou não a 20% de nHAP mostraram ser uma estratégia promissora na prevenção do desgaste erosivo-abrasivo da dentina. Além disso, o GnHSn conseguiu obliterar os túbulos dentinários.

Antimicrobial activity of probiotics against oral pathogens around orthodontic mini-implants: an in vitro study.

OBJECTIVE: The aim of this in vitro study was to evaluate the antimicrobial effect of five types of non-industrialized and industrialized probiotics on biofilms formed around orthodontic mini-implants. The null hypothesis tested was: there is no difference in the antimicrobial effect between the five types of probiotics tested around orthodontic mini-implants. METHODS: For the experiment, 120 mini-implants were immersed for seven days in Staphylococcus aureus solution for biofilm formation, and were subsequently plated in culture medium containing probiotics. The mini-implants were divided into six different groups, according to the probiotic used: G1)Lactobacillus casei; G2)Lactobacillus brevis; G3)Lactobacillus rhamnosus; G4) Lactobacillus from fermented milk Yakult®; G5) Lactobacillus from fermented milk Batavito® and G6) without use of probiotic, as negative control. Qualitative and quantitative analyses of all groups were performed using the CFU (colony forming unit) count. RESULTS: The study showed that groups G4 and G6 did not present antimicrobial activity, in comparison to groups G1, G2, G3, and G5 (p< 0.05), which demonstrated antimicrobial activity. CONCLUSION: The non-commercial probiotic bacteria, Lactobacillus casei and Lactobacillus rhamnosus, as well as commercially available fermented milk Batavito® presented promising results in the reduction of colonization of mini-implants by S. aureus. Therefore, the null hypothesis was rejected.

Effect of the several epoxy resin-based sealer compositions on adhesion interface in radicular dentin after calcium hydroxide intracanal medication removal.

BACKGROUND: This study evaluated the effects of several epoxy resin-based sealer compositions (AHP, AH Plus; ADS, Adseal; SPL, Sealer Plus) on bond strength and intratubular dentin penetration of the endodontic obturation, in root canal previously treated with calcium hydroxide intracanal medication (CH) and removed by continuous ultrasonic irrigation (CUI). MATERIAL AND METHODS: Forty-five maxillary canines were prepared up to F5 (ProTaper system), filled with CH, coronally sealed, and stored at 37ºC. After 1 week, CH was removed using 2.5% sodium hypochlorite energized by CUI. The specimens were randomly distributed in three groups (n=15) and root canal obturated, according to epoxy-based resin sealer composition (AHP, ADS or SPL). The roots were transversally sectioned in cervical, middle, and apical thirds. In each radicular third, push out bond strength using universal machine and intratubular dentin using confocal laser scanning microscopy (CLSM) and Image J Program were evaluated. Bond strength and intratubular dentin penetration were statistically evaluated by ANOVA one-way and Tukey tests and Kruskal Wallis test, respectively (α = 0.05). RESULTS: In middle and apical thirds, AHP showed higher bond strength values (p<0.05), and ADS and SPL were similar each other (p>0.05). All epoxy resin-based sealers presented similar intratubular dentin penetration, independently of the radicular thirds (p>0.05). Cohesive and mixed failures were predominant in the cervical thirds. In the middle and apical thirds, AHP showed more cohesive type failures, while ADS and SPL showed more adhesive-type failures. CONCLUSIONS: AHP has the highest bond strength in middle and apical radicular thirds, after calcium hydroxide intracanal medication removal using continuous ultrasonic irrigation, although intratubular dentin infiltration being similar among epoxy resin-based sealer with several chemical composition. Key words:Continuous ultrasonic irrigation, endodontic sealers, epoxy resin-based sealers, root canal obturation.

Effect of post-space irrigation with acid solutions on bond strength and dentin penetrability using a self-adhesive cementation system.

BACKGROUND: The aim of this study was to evaluate the effects of surface treatments with 1% peracetic acid (PA), solution containing 17% EDTA (SmearClear, Kerr Endodontics), solution containing a combination of 17% EDTA with 2% chlorhexidine (QMix, Dentsply Sirona) on the post-space root dentin compared to 2.5% sodium hypochlorite (NaOCl) on bond strength and resin tags length in dentin. MATERIAL AND METHODS: Forty human-canine roots were endodontically treated and the post space was prepared. The specimens were randomised into four groups (n = 10): control - irrigation with 2.5% NaOCl solution, PA - irrigation with 1% PA, SmearClear - irrigation with SmearClear solution, and QMix - irrigation with QMix solution. The fibre posts were cemented using a self-adhesive resin system (Relyx U200, 3M ESPE). After six months, the specimens were cross-sectioned and subjected to push-out and confocal laser microscopy tests. One-way ANOVA and Tukey's tests were used to analyse the data (α= 0.05). RESULTS: PA and QMix presented the highest bond strength values compared to the other groups (p< 0.05). There was no significant difference between the resin tags length in dentin by the groups (p = 0.75). CONCLUSIONS: Irrigation of the post space with 1% PA and QMix showed a positive clinical impact on the adhesion between the fiber post and root dentin. However, these materials had no influence on resin tags length in dentin by self-adhesive resin cement. Key words:Fiber post, adhesive cementation, self-adhesive resin cement, root dentin, irrigating solutions.

Evaluation of various methods of methylene blue removal from the post space after photodynamic therapy on the bonding interface using different resin cementation systems.

BACKGROUND: To evaluate the effects of three protocols for removing 0.01 % methylene blue from the post space after photodynamic therapy on bond strength and tag formation in the dentin of the fiber post space, using a conventional cementation system with an etch-and-rinse or universal adhesive system. METHODS: Sixty human canines were endodontically treated for fiber post cementation. The specimens were randomized into 6 groups (n = 10): G1, G2, G3, G4, G5, and G6. The G1, G2, and G3 groups were irrigated with saline solution, 2.5 % sodium hypochlorite (NaOCl), and 2.5 % NaOCl, agitated by passive ultrasonic irrigation (PUI), respectively. In these groups, a conventional cementation system with etch-and-rinse adhesive was used. The G4, G5, and G6 groups were irrigated with the respective solutions mentioned above and cemented using a conventional cementation system with universal adhesive. Tag formation in the dentin was evaluated by confocal laser scanning microscopy. The push-out bond strength test was performed on three thirds of the specimens. RESULTS: In the cervical and middle thirds, the greatest extent of dentin tag formation occurred in the G1 (p = 0.023 and p = 0.033, respectively). In the apical third, G1, G2, and G3 demonstrated similar tag formation between themselves (p = 0.089). In the cervical and middle thirds, G4 demonstrated the highest bond strength when compared to the other groups (p < 0.05). CONCLUSION: The protocols for removing 0.01 % methylene blue with NaOCl, irrespective of the involvement of passive ultrasonic irrigation, negatively effects the bond strength and tag formation in the dentin of the post space.

Molars Fracture Resistance with Class II Cavities Restored with Different Resin - Based Materials / Resistência à Fratura de Molares com Cavidades Classe II Restauradas com Diferentes Materiais à Base de Resina

The teeth weakening due to the preparation of class II mesio-occluso-distal cavities is a challenge for the clinician. The objective of this study was to evaluate the molars fracture resistance with class II mesio-occluso distal cavities restored with different restorative techniques and materials. Forty extracted molars were divided into 5 groups: Group 1 ­ intact healthy teeth (positive control); Group 2 ­ unrestored teeth with mesio-occluso distal class II cavities (negative control); Groups 3 to 5 ­ restored teeth with standardized dimensions. In groups 3 to 5, the cavities were restored with flow resin only, flow resin coated with a nano-hybrid resin, and nano-hybrid resin only, respectively. All specimens were tested for resistance to fracture using an axial compressive load, a metallic sphere measuring 8 mm in diameter on a universal testing machine EMIC DL-2000. A 10 kN load cell operated at a speed of 5 mm/min until the tooth fracture. Data were subjected to analysis of variance and Tukey's tests (α = 0.05). Group 3 showed higher fracture strength (2243.1 ± 473.7N) when compared to groups 2, 4 and 5. This difference was statistically significant (p<0.05). The fracture strength of teeth restored with flow mesio occluso-distal restorations was similar to that of intact natural teeth. (AU)

O enfraquecimento dos dentes devido às preparações de cavidades mesio-ocluso-distal é um desafio para o clínico. O objetivo deste estudo foi avaliar a resistência à fratura de molares com cavidades mesio-ocluso-distais classe II restauradas com diferentes técnicas e materiais restauradores. Quarenta molares extraídos foram divididos em 5 grupos: Grupo 1 ­ dentes saudáveis intactos (controle positivo); Grupo 2 ­ dentes não restaurados com cavidades mesio-occluso-distais classe II (controle negativo); Grupos 3 a 5 ­ dentes restaurados com dimensões padronizadas. Nos grupos 3 a 5, as cavidades foram restauradas apenas com resina flow, resina flow recoberta com uma resina nanohíbrida e somente resina nano-híbrida, respectivamente. Todas as amostras foram testadas quanto à resistência à fratura usando uma carga compressiva axial, usando uma esfera metálica medindo 8 mm de diâmetro em uma máquina de teste universal EMIC DL-2000. Uma célula de carga de 10 kN operava a uma velocidade de 5 mm/min até a fratura do dente. Os dados foram submetidos à análise de variância e testes de Tukey (α = 0,05). O grupo 3 apresentou maior resistência à fratura (2243,1 ± 473,7N) quando comparado aos grupos 2, 4 e 5. Essa diferença foi estatisticamente significante (p <0,05). A resistência à fratura dos dentes restaurados com resina flow foi semelhante à dos dentes naturais intactos. (AU)

Antimicrobial activity of probiotics against oral pathogens around orthodontic mini-implants: an in vitro study

ABSTRACT Objective: The aim of this in vitro study was to evaluate the antimicrobial effect of five types of non-industrialized and industrialized probiotics on biofilms formed around orthodontic mini-implants. The null hypothesis tested was: there is no difference in the antimicrobial effect between the five types of probiotics tested around orthodontic mini-implants. Methods: For the experiment, 120 mini-implants were immersed for seven days in Staphylococcus aureus solution for biofilm formation, and were subsequently plated in culture medium containing probiotics. The mini-implants were divided into six different groups, according to the probiotic used: G1)Lactobacillus casei; G2)Lactobacillus brevis; G3)Lactobacillus rhamnosus; G4) Lactobacillus from fermented milk Yakult®; G5) Lactobacillus from fermented milk Batavito® and G6) without use of probiotic, as negative control. Qualitative and quantitative analyses of all groups were performed using the CFU (colony forming unit) count. Results: The study showed that groups G4 and G6 did not present antimicrobial activity, in comparison to groups G1, G2, G3, and G5 (p< 0.05), which demonstrated antimicrobial activity. Conclusion: The non-commercial probiotic bacteria, Lactobacillus casei and Lactobacillus rhamnosus, as well as commercially available fermented milk Batavito® presented promising results in the reduction of colonization of mini-implants by S. aureus. Therefore, the null hypothesis was rejected.

RESUMO Objetivo: O objetivo do presente estudo in vitro foi avaliar o efeito antimicrobiano de cinco tipos de probióticos não industrializados ou industrializados em biofilmes formados ao redor de mini-implantes ortodônticos. A hipótese nula testada foi: não há diferença no efeito antimicrobiano entre os cinco tipos de probióticos testados em torno dos mini-implantes ortodônticos. Métodos: Para o experimento, as cabeças de 120 mini-implantes foram imersas por sete dias em solução de Staphylococcus aureus para formação de biofilme e, posteriormente, semeadas em meio de cultura contendo probióticos. Os mini-implantes foram divididos em seis grupos diferentes, de acordo com o probiótico utilizado: G1)Lactobacillus casei; G2)Lactobacillus brevis; G3)Lactobacillus rhamnosus; G4) lactobacilos do leite fermentado Yakult®; G5) lactobacilos do leite fermentado Batavito®; e G6) sem uso de probiótico, como controle negativo. As análises qualitativas e quantitativas de todos os grupos foram realizadas usando a contagem de UFCs (unidades formadoras de colônia). Resultados: O estudo mostrou que os grupos G4 e G6 não apresentaram atividade antimicrobiana, em comparação aos grupos G1, G2, G3 e G5 (p< 0,05), os quais demonstraram atividade antimicrobiana. Conclusão: As bactérias probióticas não comerciais, Lactobacillus casei e Lactobacillus rhamnosus, assim como o leite fermentado comercializado, Batavito®, apresentaram resultados promissores na redução da colonização dos mini-implantes por S. aureus. Portanto, a hipótese nula foi rejeitada.

Assessment of Marginal Adaptation Before and After Thermo-Mechanical Loading and Volumetric Shrinkage: Bulk Fill versus Conventional Composite / Evaluación de la Adaptación Marginal Antes y Después de la Carga Termomecánica y la Contracción Volumétrica: Relleno Bulk-Fill- versus Compuesto Convencional

ABSTRACT: The objective of the study was to evaluate marginal adaptation of Class II mesial-occlusal-distal (MOD) restorations before and after thermo-mechanical loading and volumetric shrinkage of the bulk-fill vs conventional composite resin. For marginal adaptation assessment, 24 Class II MOD cavities with cervical margins extending 1.0 mm below (distal) and 1.0 mm beyond (mesial) the cement-enamel junction were prepared in extracted human molars. The teeth were filled as follows: Group A - bulk-fill with SureFil SDR flow (first increment, 4 mm; second increment, 2 mm); Group B - bulk-fill with SureFil SDR flow as a base (first increment, 4 mm) and covered with the conventional nanohybrid composite Esthet-X HD (second increment, 2 mm); and Group C - incrementally filled with Esthet-X HD. Marginal adaptation was evaluated by scanning electron microscopy before and after thermomechanical loading (240,000 loading cycles and simultaneous 600 thermal cycles). To evaluate volumetric polymerization shrinkage, a semi-spherical mold was filled with the tested composites and placed in an AccuVol device after light curing. Both before and after loading, marginal adaptation in cervical dentin was superior (p < 0.05) for Groups A and B compared with Group C. In cervical enamel, Group B showed better marginal adaptation than Group C, and Group A presented intermediary results, between Groups B and C. Furthermore, bulk-fill flow resulted in greater shrinkage than Esthet-X HD. A significant improvement of marginal adaptation was observed when bulkfill flow was used instead of conventional composite resin both before and after thermomechanical loading. However, the bulk-fill flow presented higher volumetric polymerization shrinkage than the conventional composite.

RESUMEN: El objetivo de este trabajo consistió en evaluar la adaptación marginal de las restauraciones mesiales-oclusales-distales (MOD) de Clase II antes y después de la carga termo-mecánica y la contracción volumétrica de la carga compuesta de resina "bulk-fill" en comparación con resina convencional. Para la evaluación de adaptación, se prepararon 24 cavidades MOD de Clase II en molares humanos extraídos, los que se restauraron de la siguiente manera: Grupo A: restaurado con resina fluida Bulk-Fill SureFilSDR (primer incremento, 4 mm; segundo incremento, 2 mm); Grupo B: restaurado con resina fluida Bulk-Fill SureFil SDR (primer incremento, 4 mm) y cubierto con resina compuesta nanohíbrida Esthet-X HD (segundo incremento, 2 mm); y Grupo C - rellenado incrementalmente con Esthet-X HD. La adaptación marginal se evaluó mediante microscopía electrónica de barrido antes y después de la carga termomecánica (240.000 ciclos de carga y 600 ciclos térmicos simultáneos). Para evaluar la contracción volumétrica de la polimerización, se llenó un molde semiesférico con los compuestos probados y se colocó en un dispositivo AccuVol después del fotopolimerización. Tanto antes como después de la carga, la adaptación marginal en la dentina cervical fue superior (p <0,05) para los grupos A y B en comparación con el grupo C. En el esmalte cervical, el grupo B mostró una mejor adaptación marginal que el grupo C, y el grupo A presentó resultados intermedios, entre Grupos B y C. Se observó una mejora significativa de la adaptación marginal al utilizar la resina fluida Bulk-Fill en lugar de resina compuesta convencional tanto antes como después de la carga termomecánica. Sin embargo, la resina fluida 'Bulk-Fill' presentó una mayor contracción volumétrica de polimerización que el compuesto convencional.

Effect of high concentrated fluoride-based dentifrice on the hardness, roughness, and color of the bleached enamel.

CONTEXT: Remineralizing agents have been recommended to restore the integrity of bleached enamel. AIMS: The aim of this study was to evaluate the effect of fluoride at high concentration (5000 ppm) applied to bleached enamel. MATERIALS AND METHODS: A total of 30 specimens obtained from newly extracted third molars were divided into two groups (n = 15) as follows: control group and fluoride group. Specimens of both groups received bleaching treatment with 35% hydrogen peroxide, were then submitted to the Vickers hardness number/colorimetric test (VHN/CT) (n = 5) and Ra (n = 10) tests, and stored in artificial saliva. After bleaching, fluoride group received the application of a fluoride-based dentifrice, during 5 min. VHN, RS, and CT analysis of both groups were performed before and after treatments. For VHN, five indentations per specimen were performed, using a microdurometer. Ra analysis was performed with a rugosimeter. The color was analyzed through the CIE L* a* b* system, respectively, using a colorimeter. STATISTICAL ANALYSIS: For intergroup statistical analysis, ANOVA with Tukey's posttest was used. All tests were calculated at a significance level of 5%. RESULTS: There was statistically significant difference (P < 0.01) between the analyzed groups, on VHN, Ra, and CT evaluations. CONCLUSIONS: The use of fluoride-based dentifrice at 5000 ppm was effective in minimizing the deleterious effects on bleached enamel.

Effect of low-level laser therapy combined with 5000 parts per million fluoride dentifrice on postbleaching sensitivity: A clinical, randomized, and double-blind study.

OBJECTIVE: The aim of this double-blind, randomized, controlled clinical study was to assess the efficacy of low-level laser therapy (LLLT) combined with 5000 ppm fluoride dentifrice on postbleaching sensitivity in teeth exposed to 35% hydrogen peroxide for four weeks. MATERIALS AND METHODS: Twenty-five volunteers were evaluated using the split-mouth model in which the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO, in which the laser tip was positioned without the emission of light (placebo effect) + 5000 ppm sodium fluoride, or GLASER, which comprised LLLT + 5000 ppm sodium fluoride. For both groups, LLLT and placebo were used before bleaching, whereas fluoride was applied after bleaching. LLLT was applied at two points: on the central cervical and medial regions of the incisors, canines, and premolars in the corresponding hemi-arch. At each point, 60 J/cm2 was applied for 16 seconds with an irradiance of 3.75 W/cm2 using the therapeutic infrared device. To assess tooth sensitivity, a modified visual analogue scale was used after an evaporative stimulus, and a daily pain questionnaire was also applied. RESULTS: The Wilcoxon and Friedman tests demonstrated a significant difference in the incidence of sensitivity pain between GPLACEBO and GLASER (P ≤ .05), with different evaluation times. CONCLUSION: Teeth treated with laser therapy in combination with the topical use of sodium fluoride at each bleaching session demonstrated less sensitivity compared with the application of sodium fluoride only. CLINICAL SIGNIFICANCE: The use of a low-level laser therapy in combination with topical use of sodium fluoride improves symptoms of dentin sensitivity at each bleaching session.

Ceramic Laminate Veneers for Reestablishment of Esthetics in Case of Lateral Incisor Agenesis.

The increasing demand of patients looking for esthetics has resulted in the development of several techniques to restore anterior teeth. Conservative treatments should always be the first therapeutic option for the solution of aesthetic problems involving morphological changes and usually provide the result that the patient expects. In this context, ceramic laminate veneers, also known as "contact lenses," are capable to provide an extremely faithful reproduction of natural teeth with great color stability and periodontal biocompatibility. Minimal or no preparation veneers are heavily advertised as the answer to patients' cosmetic needs, when properly indicated by the dentist. This paper reports a clinical case where lateral incisor agenesis was aesthetically corrected using ceramic laminates.

Restauração de dente posterior com resina Bulk Fill: relato de caso clínico / Posterior tooth restoration with a bulk fill composite: a case report

Objetivo: Demonstrar o uso da resina Bulk Fill como material de preenchimento em restaurações posteriores. Material e métodos: Paciente do sexo feminino, 28 anos, compareceu a clínica privada relatando incômodo nos dentes da região postero inferior esquerda. Após realização dos exames clínicos e radiográficos foi observada que havia restauração ocluso distal (OD) em resina composta com fratura da margem estendendo para face proximal e ausência de cárie no dente 35. Presença de cárie secundária sob a restauração de amálgama mesio ocluso distal (MOD) no dente 36 e restauração satisfatória em resina composta no dente 37. Como plano de tratamento foi proposta a substituição das restaurações dos dentes 35 e 36. Resultados: As restaurações dos dentes 35 e 36 foram removidas e após limpeza da cavidade, foi realizado tratamento dentinário com sistema adesivo autocondicionante e adaptação de matriz metálica. Inicialmente, o dente 35 foi restaurado com resina micro-híbrida e em seguida a restauração do dente 36 com a inserção da resina Bulk Fill com auxílio de um dispensador. A ponta do compule foi posicionada na parte mais profunda da cavidade e a resina injetada até o preenchimento de 4 mm. A restauração foi finalizada com incrementos de 2 mm da resina micro-híbrida na oclusal e polida após o período de 24 horas. Conclusões: A resina Bulk Fill pode ser utilizada como material de preenchimento em restaurações de dentes posteriores, permitindo a confecção de restaurações com maior praticidade e menor tempo clínico.

Objective: To demonstrate the use of a Bulk Fill composite as a fill material in posterior restoration. Material and Methods: Female patient, 28 years old, was presented to a private clinic with complaints of her lower left teeth region. Clinical and radiographic examination revealed: (i) an occlusal-distal composite resin restoration on tooth 35 (lower left second premolar) with fractured margin extending to the proximal face, but no signs of carie; (ii) presence of secondary caries under a mesialocclusal- distal (MOD) amalgam restoration on tooth 36 (lower left first molar), and (iii) satisfactory composite resin restoration on tooth 37 (lower left second molar). As a treatment plan it was proposed the replacement of the restoration on teeth 35 and 36. Results: The restoration on the teeth 35 and 36 were removed and after cleaning the cavity, dentin treatment with a self-etching adhesive system and metal matrix adaptation were performed. The tooth 35 was initially restored with a micro-hybrid resin and then restoration of the tooth 36 was carried out using a Bulk fill resin with the aid of a dispenser. The tip of the dispenser was placed in the deepest part of the cavity and the resin injected to a 4-mm filling. The restoration was completed by adding 2-mm increments of micro-hybrid resin on the occlusal face of the tooth, followed by polishing after 24h. Conclusion: Bulk Fill resin can be used as a fill material in posterior tooth restoration, thereby allowing restoration to be made with greater convenience and shorter clinical time.

Marginal adaptation of class II cavities restored with bulk-fill composites.

OBJECTIVES: To determine the marginal adaptation of bulk-fill composites in class II MO cavities. METHODS: Standardized class II MO cavities with bevelled enamel margins were prepared in 40 extracted human molars. The teeth were randomly assigned to one of the five experimental groups (n=8). The teeth were restored with two horizontal increments of composite (4mm and 2mm thickness). The experimental groups were (1st/2nd increment): Gr. A - Venus Bulk-Fill/Venus Diamond; Gr. B - Tetric EvoCeram BulkFill/Tetric EvoCeram; Gr. C - Surefil SDR/Ceram-X; Gr. D - SonicFill; Gr. E - Ceram-X/Ceram-X (control). After finishing procedures, impressions were made using a polyvinyl siloxane and epoxy resin replicas were obtained. Thermo-mechanical stressing was carried out 24h after the restorative procedure. All specimens were submitted to 240,000 occlusal loading and simultaneous 600 thermal cycles in water at 5°C and 50°C. After loading, a new set of epoxy resin replicas was obtained. Scanning electron microscopy was carried out at 200× magnification. Results for the marginal adaptation were expressed as percentages of continuity relative to the exposed interface and analyzed by ANOVA and Duncan post hoc test (p<0.05). RESULTS: In enamel, no significant differences were detected before and after thermo-mechanical loading between groups. In dentine, the worst results were observed in Gr. A CONCLUSION: By applying simple layering techniques, bulk-fill materials do not allow better marginal adaptation than a standard composite. CLINICAL SIGNIFICANCE: A new class of resin-base composite (bulk-fill) was recently launched on the market. The bulk-fill composites exhibited adequate marginal adaptation and similar to the results of the standard composite.

Influence of filler charge on gloss of composite materials before and after in vitro toothbrushing.

OBJECTIVES: This study evaluated the gloss behaviour of experimental resin composites loaded with different filler percentages, immediately after polishing and after toothbrushing simulation. METHODS: Sixteen disc-shaped specimens were fabricated for each different-charged composite (40%, 50%, 60%, 70% and 75%) and polished with SiC abrasive papers. Gloss measurements were made prior to simulated toothbrushing. The specimens were subjected to the simulation for 5, 15, 30 and 60 min using an electrical toothbrush with a standardized pressure while being immersed in a toothpaste/artificial saliva slurry. RESULTS: Baseline composite gloss values ranged from 69.7 (40%) to 81.3 (75%) GU (gloss units) and from 18.1 (40%) to 32.3 (75%) GU after 1h of brushing. Highest gloss values were obtained by 75%-charged resin, while the lowest values were obtained by the 40%-charged one. CONCLUSIONS: All tested materials showed a gloss decrease. However, the higher filler load a composite resin has, the higher gloss it can achieve. CLINICAL SIGNIFICANCE: Gloss of resin composite materials is an important factor in determining aesthetic success of anterior restorations, and this property may vary according to the filler charge of the restorative material. Higher filler load of a composite resin results in higher gloss values.

Anterior restorations in bleached teeth: difficulty establishing the color after bleaching.

It is becoming more common for patients to look for cosmetic procedures in dental offices. The search for lost or desired esthetics by patients is increasingly frequent and the professional must be able to meet this demand. To do this, dentists not only need to return the tooth back to its normal functioning state but also promote esthetic excellence. In this context, the association of cosmetic procedures, such as teeth whitening and restorative procedures, such as direct adhesive restorations is very common. The composite resins employed nowadays allow the reproduction of various optical properties of natural teeth. With these composite resins, it is possible to reproduce features such as translucency, opacity and specific features of the dental element, to bring back the esthetic harmony of the smile. This article reports a clinical case demonstrating the placement, in a stratified manner, of composite resins in bleached teeth, as well as the reproduction of optical and natural aspects of the teeth. In order to achieve esthetic and functional success of the restored procedure, it is important to be familiar with the new techniques and new materials in the market and above all, we must know when and where to use them.

Assessment of the ability to relate anterior tooth form and arrangement to gender.

PURPOSE: This study evaluated the assumption that there are morphological differences between the natural anterior dentition of men and women. The goal of the study was to determine the gender of patients based on the appearance of the anterior teeth in photographs. MATERIALS AND METHODS: Laymen and observers from different specialties were asked to determine the gender of individuals based on the shape and arrangement of anterior teeth. Forty anterior dentition photographs of dental students of both genders (20 women, 20 men) between 18 and 26 years old were selected, coded, and randomly arranged in an album. The albums were delivered to five groups of observers: general practitioners (recently graduated dentists), prosthodontists, orthodontists, restorative dentists (specialists in cosmetic and restorative dentistry), and laymen (control group). The observers evaluated the photographs twice at 1-week intervals. RESULTS: The average correctly identified values in women and men were 57.6% and 58.8%, respectively. There was no statistical difference between observers and between each group of professionals and the laymen group (p > 0.05). An intraobserver agreement was not observed between the evaluations (kappa = -0.01). CONCLUSION: The results of this limited study indicated that it was not possible to differentiate gender by viewing photographs of anterior teeth.