Abstract Objective: To analyze the existing state legislation, including not only the ordinary laws, but also their infralegal regulation and the state legislation on Hospital Dentistry. Material and Methods: A survey was carried out in the databases of the Legislative Assemblies of the Brazilian States and the Federal District, as well as the Regional and Federal Councils of Dentistry in Brazil. Subsequently, a survey was carried out in the databases of the Ministry of Health, State Dental Councils and Federal Dental Council in Brazil. Results: Only 8 Brazilian states have legislation in force regarding hospital dentistry, which represents 29.63% of the federative units. Among the Brazilian regions, the Midwest presented the highest prevalence of the laws found (37.50%), followed by the North (25%) and the other regions with the same coverage (12.50%). Also, an orientation and an ordinance from the Ministry of Health, six resolutions from the Federal Council of Dentistry, and a technical note from the National Health Surveillance Agency were found. Conclusion: Several States do not have rules on the subject, making it imperative to create a federal rule that not only imposes the presence of the dentist, but also regulates the proportion of the team, workload, and availability.

Abstract Objective: To compare the clinical effect of two desensitizing agents used before the application of a bleaching gel based on 35% hydrogen peroxide (HP). Material and Methods: 30 patients were selected, and two desensitizing agents with different mechanisms of action were applied: Fluorine Neutral 2% (FN), which acts by blocking dentinal canaliculi while Potassium Nitrate 5% with 2% Sodium Fluoride (PN/SF) that acts in nerve transmission and blockade. Desensitizers were used before the application of 35% HP. For whitening, three clinical sessions were performed, with an interval of seven days, with three applications of the bleaching gel for 15 minutes, totaling 45 minutes/session. Tooth sensitivity (TS) was assessed with the numerical analog scale, and a spectrophotometer was used to obtain the color variation (ΔE). ΔE were submitted to ANOVA and Tukey test (p<0.05), and TS data were submitted to a two-way ANOVA analysis. Results: For sensitivity experience, the Tukey test indicated differences between PN/SF and the placebo I, but there was no statistically significant difference between FN and the placebo II. The TS was lower when the desensitizing gel was used during the bleaching procedure compared to after treatment, regardless of the desensitizing agents. Conclusion: PN/SF before in-office tooth bleaching can reduce TS intensity, and the use of desensitizing gel before bleaching did not affect the bleaching efficacy.

ABSTRACT OBJECTIVE To assess the changes in stress levels, social behavior, dietary and parafunctional habits, oral hygiene, among other conditions perceived by dental students in Brazil during the Covid-19 pandemic and evaluated the correlations between stress level and other variables. METHODS An online questionnaire was developed and validated. Undergraduates enrolled in private and public dental schools were recruited by convenience sampling. Data were collected on the perceived changes regarding stress levels, financial and social characteristics, dietary habits, oral hygiene, health conditions, and parafunctional habits. Quantitative variables were expressed as absolute and relative frequencies. Wilcoxon test evaluated comparisons between perceived changes, and correlations between changes in stress levels and other variables were analyzed by Spearman correlation (α = 0.05). RESULTS A total of 638 dental students, mean age of 22.95 ± 4.10 years, participated in the study. During the pandemic, the reported stress levels increased while household income decreased (p < 0.05). Late dinners and mindless eating increased in frequency, whereas oral hygiene decreased (p < 0.05). Most of the health conditions and parafunctional habits assessed changed (p < 0.05). Perceived stress levels showed poor negative correlations with household income (rS = −0.14), poor positive correlations with the pressure to contribute financially in the household (rS = 0.19), and poor positive correlations with food choice frequency (rS = 0.15) (p < 0.05). CONCLUSIONS Dental students reported perceived changes in stress levels, dietary habits, oral hygiene, health conditions, parafunctional habits, and social behavior. Moreover, the results showed poor correlations, as students with higher stress levels tended to have the lowest household income, feel pressured to contribute financially in the household, and present a high meal intake frequency.

ABSTRACT OBJECTIVE To assess the changes in stress levels, social behavior, dietary and parafunctional habits, oral hygiene, among other conditions perceived by dental students in Brazil during the Covid-19 pandemic and evaluated the correlations between stress level and other variables. METHODS An online questionnaire was developed and validated. Undergraduates enrolled in private and public dental schools were recruited by convenience sampling. Data were collected on the perceived changes regarding stress levels, financial and social characteristics, dietary habits, oral hygiene, health conditions, and parafunctional habits. Quantitative variables were expressed as absolute and relative frequencies. Wilcoxon test evaluated comparisons between perceived changes, and correlations between changes in stress levels and other variables were analyzed by Spearman correlation (α = 0.05). RESULTS A total of 638 dental students, mean age of 22.95 ± 4.10 years, participated in the study. During the pandemic, the reported stress levels increased while household income decreased (p < 0.05). Late dinners and mindless eating increased in frequency, whereas oral hygiene decreased (p < 0.05). Most of the health conditions and parafunctional habits assessed changed (p < 0.05). Perceived stress levels showed poor negative correlations with household income (rS = −0.14), poor positive correlations with the pressure to contribute financially in the household (rS = 0.19), and poor positive correlations with food choice frequency (rS = 0.15) (p < 0.05). CONCLUSIONS Dental students reported perceived changes in stress levels, dietary habits, oral hygiene, health conditions, parafunctional habits, and social behavior. Moreover, the results showed poor correlations, as students with higher stress levels tended to have the lowest household income, feel pressured to contribute financially in the household, and present a high meal intake frequency.

Abstract The objective of this study was to compare the protein profile of the acquired enamel pellicle (AEP) formed in vivo in patients with or without gastroesophageal reflux disease (GERD), and with or without erosive tooth wear (ETW). Twenty-four volunteers were divided into 3 groups: 1) GERD and ETW; 2) GERD without ETW; and 3) control (without GERD). The AEP formed 120 min after prophylaxis was collected from the lingual/palatal surfaces. The samples were subjected to mass spectrometry (nLC-ESI-MS/MS) and label-free quantification by Protein Lynx Global Service software. A total of 213 proteins were identified, or 119, 92 and 106 from each group, respectively. Group 2 showed a high number of phosphorylated and calcium-binding proteins. Twenty-three proteins were found in all the groups, including 14-3-3 protein zeta/delta and 1-phosphatidylinositol. Several intracellular proteins that join saliva after the exfoliation of oral mucosa cells might have the potential to bind hydroxyapatite, or participate in forming supramolecular aggregates that bind to precursor proteins in the AEP. Proteins might play a central role in protecting the dental surface against acid dissolution.

Abstract To analyze the biocompatibility of the scaffold produced from a natural polymer derived from castor oil through hemolytic activity and antimicrobial activity, to enable the clinical application. Three in vitro tests were performed: Hemolytic activity test - Polymer partially dissolved in contact with blood agar; Hemolytic activity test in sheep's blood - Polymer extract with red blood cells solution; Antimicrobial activity test - Solid polymer in direct contact with E. Coli and S. Aureus. For hemolytic tests, none of the samples showed hemolysis. Negative hemolytic activity is a good indicator, as the maintenance of the blood clot in the area of the lesion is essential for the formation of new tissue. For the antimicrobial activity test, no significant activity was observed against the bacteria used. The polymer is not toxic to red blood cells, being viable for clinical application as a matrix for tissue regeneration.

Abstract This study evaluated the influence of non-thermal argon plasma applied to dentin on the shear strength of two adhesive systems. Ninety tooth fragments were embedded in epoxy resin and distributed into experimental groups (n=15): G1 and G4 - adhesive systems applied according to the manufacturers’ instructions; G2 and G5 - dentin treated with non-thermal argon plasma for 30 seconds before hybridization; G3 and G6 - dentin treated with non-thermal argon plasma for 30 seconds after hybridization. Cylinders were made with composite resin in the adhesive area, and the specimens were submitted to the shear strength test. Higher values were observed when applying the plasma treatment after hybridization (G1: 26.51 MPa, G2: 29.22 MPa, G3: 30.27 MPa, G4: 22.66 MPa, G5: 28.33 MPa, G6: 29.32 MPa). The treatment with non-thermal argon plasma significantly increased the shear strength values regardless of the application time.

Abstract To analyze the surface topography and mechanical properties of a polyurethane derived from castor oil reinforced with hydroxyapatite (PU–HA) for bone fixation. The surface analysis was performed by Scanning Electron Microscopy (SEM) and the mechanical properties by Vickers microhardness and tensile tests. The SEM images showed that the PU surface presented important characteristics for materials intended for bone fixation, such as an irregular and porous surface. The analysis showed a surface with alternating areas with depressions and elevations of approximately 80±100 µm, presence of pores of 12 µm in size. The microhardness analysis showed values of 0.42±1.01 HV for PU–HA plates, lower in relation to the poly lactic-co-glycolic acid (PLGA) plate (control group). The elastic modulus and ultimate tensile strength of 317.4 MPa, and 35.57 MPa for PLGA sample, 1.187 MPa, and 0.29 MPa for PU–HA sample. The PU produced showed good surface properties, however demands better mechanical properties.

Resumo Introdução Com o intuito de se evitar as tensões geradas durante a contração de polimerização das resinas compostas, foram desenvolvidas as resinas compostas de baixa contração de polimerização. Objetivo Avaliar a resistência à microtração em cavidades classe I restauradas com tratamento ácido do ângulo cavo superficial e resina composta indicada para dentes posteriores. Material e método Foram selecionados 48 molares hígidos que foram divididos em 6 grupos (n=8), sendo que 3 desses tiveram o esmalte cavo superficial condicionado com ácido fosfórico a 35%. Os dentes foram restaurados com o sistema adesivo Clearfil SE Bond e as resinas compostas Filtek Z350 XT, Empress Direct e Charisma Diamond, fotoativadas por 40 segundos. Após 24 horas, os dentes foram levados para máquina de corte, na qual foram realizados cortes no sentido vestíbulo-lingual e no sentido mésio-distal obtendo – se palitos de 0,9×0,9 mm que foram levadas para a máquina de ensaio universal para a realização do teste de microtração. Para análise estatística foi realizado análise de variância e teste de Tuckey (p < 0,05). Resultado Não houve diferença estatística significante entre os grupos avaliados. Conclusão O condicionamento ácido do ângulo cavo superficial não influenciou no desempenho das restaurações provavelmente devido ao sistema adesivo utilizado.

Abstract Introduction To prevent the shrinkage stresses produced during polymerization, composite resins of low polymerization shrinkage were developed. Objective To evaluate the microtensile bond strength in class I cavities restored by acid-etching the cavosurface angle and with composite resins indicated for posterior teeth. Material and method 48 healthy molars were selected and divided into six groups (n = 8), considering that the cavosurface enamel of three groups was etched with 35% phosphoric acid. The teeth were restored with the Clearfil SE Bond adhesive system and Filtek Z350 XT, Empress Direct, and Charisma Diamond composite resins, which were light-cured for 40 seconds. After 24 hours, the teeth were taken to a cutting machine, which produced sections in the buccolingual and mesiodistal directions. This resulted in toothpicks of 0.9×0.9 mm that were taken to the universal testing machine for the microtensile bond strength test. Statistical analysis was performed with ANOVA and Tukey’s test (p < 0.05). Result There was no statistically significant difference between the groups evaluated. Conclusion Acid-etching the cavosurface angle did not affect the performance of restorations, probably due to the adhesive system used.

Resumo Introdução Com o aumento da procura por procedimentos estéticos, dúvidas surgem quanto à manutenção e regressão de cor, especialmente, no que tange a necessidade de restrição quanto à alimentos escuros durante o procedimento clareador ou a sua influência quanto à estabilidade e eficácia do tratamento. Objetivo Avaliar a influência de agentes pigmentantes sobre o esmalte dental durante o tratamento clareador imediato com peróxido de hidrogênio a 35%. Material e método 60 dentes bovinos foram divididos em 6 grupos (G) (n=10): G1: água destilada (controle), G2: café, G3: refrigerante à base de cola, G4: vinho, G5: chá-mate, e G6: açaí industrializado. As amostras foram submetidas ao clareamento imediato utilizando peróxido de hidrogênio a 35% durante 21 dias (3 aplicações de 15 minutos por sessão a cada 7 dias) e submetidas à imersão dos pigmentos entre cada sessão durante 15 minutos. A avaliação da cor foi realizada antes do inicio do clareamento e após 21 dias, mediante o uso do espectrofotômetro. Os dados obtidos foram submetidos ao ANOVA one-way e análise de heterocedasticidade pelos testes de Welch e Brown-Forsythe. O teste de Tamhane foi utilizado para a comparação entre os grupos. Resultado Houve alteração de cor visível ao olho nu, uma vez que a média de ΔE em todos os grupos testados foi maior que 3,7. Contudo, não houve diferença estatística entre o grupo controle em relação aos grupos avaliados. Conclusão O contato de agentes pigmentantes no esmalte dental bovino não influenciou o resultado final do clareamento dental imediato.

Abstract Introduction Considering the increased search for esthetic procedures, questions emerge about the maintenance and regression of color, especially regarding the need to restrict dark foods during bleaching procedures or their influence on the stability and effectiveness of the treatment. Objective To assess the influence of staining agents on tooth enamel during immediate bleaching treatment with 35% hydrogen peroxide. Material and method Sixty bovine teeth were divided into six groups (G) (n=10): G1: distilled water (control); G2: coffee; G3: cola soft drink; G4: wine; G5: mate tea; and G6: industrialized açaí. The samples were subjected to immediate bleaching using 35% hydrogen peroxide for 21 days (three applications of 15 minutes per session, every seven days) and pigment immersion between each session for 15 minutes. The color was assessed before starting bleaching and after 21 days, using a spectrophotometer. The data obtained were subjected to one-way ANOVA and heteroscedasticity analysis by the Welch and Brown-Forsythe tests. The Tamhane test was used for group comparison. Result The color change was visible to the naked eye, considering the mean ΔE in all groups tested was higher than 3.7. However, there was no statistical difference between the control group and the groups assessed. Conclusion The contact of staining agents on bovine tooth enamel did not affect the final result of the immediate tooth bleaching.

Abstract Objective This in vitro study evaluated the effect of commercial whitening dentifrices on erosive tooth wear (ETW) of bovine enamel samples, in comparison with commercial regular dentifrices. Methodology Sixty bovine crowns were embedded in acrylic resin, polished and then had their baseline profile determined. They were randomly assigned to 5 groups (n=12/group), according to the type of commercial dentifrice to be tested: GI – Crest Anti-cavity Regular; GII – Crest 3D White; GIII – Colgate Total 12 Clean Mint; GIV – Colgate Optic White; GV – Placebo (negative control, fluoride-free dentifrice). The samples were submitted to daily erosive and abrasive challenges for 3 days. The erosive challenges were performed 3 times a day by immersing the specimens in 0.1% citric acid solution (pH 2.5) for 90 s. Each day after the first and last erosive challenges, the specimens were subjected to the abrasive challenge for 15 s, using a toothbrushing machine (Biopdi, São Carlos, SP, Brazil), soft toothbrushes and slurry (1:3 g/ml) of the tested toothpastes (1.5 N). The specimens were kept in artificial saliva between the challenges. The final profile was obtained and the ETW (µm) was calculated. Data were analyzed by Kruskal-Wallis and Dunn’s tests (p<0.05). Results All dentifrices tested significantly reduced the enamel wear in comparison with the Placebo, except GIII. The median (95% CI) ETW was 1.35 (1.25-1.46)bc for GI, 1.17 (1.01-1.34)cd for GII, 1.36 (1.28-1.45)ab for GIII, 1.08 (1.04-1.14)d for GIV and 2.28 (2.18-2.39)a for GV. Conclusion When dentifrices from the same manufacturer were compared, the whitening dentifrices led to similar or less wear than the regular ones.

Abstract Objective To clinically assess the effect of desensitizing gels and dentifrices on the reduction in pain sensitivity and color variation during tooth bleaching. Methodology A total of 108 volunteers were randomly separated into the following groups of n=12: GT/S-glycerine and thickener/sucralose; NF/S-potassium nitrate and sodium fluoride/sucralose; NA/S-potassium nitrate and arginine/sucralose; GT/AC-glycerine and thickener/arginine and calcium carbonate; NF/AC-potassium nitrate and sodium fluoride/arginine and calcium carbonate; NA/AC-potassium nitrate and arginine/arginine and calcium carbonate; GT/PN-glycerine and thickener/potassium nitrate; NF/PN-potassium nitrate and sodium fluoride/potassium nitrate; and NA/PN-potassium nitrate and arginine/potassium nitrate. Sensitivity was assessed with the numerical analogue scale, and color variation (ΔE) was measured with a spectrophotometer. The sensitivity values obtained were subjected to a multivariate analysis of variance (MANOVA) and color variation values were subjected to a randomized analysis of variance (p<0.05). Results The NF/AC, NA/AC, NF/PN, and NA/PN groups presented lower sensitivity values and reduced sensitivity compared to those of the other groups throughout the clinical sessions. None of the groups showed sensitivity at the 24-week assessment. Statistically, no significant difference were observed in the color values among the groups four weeks after the beginning of bleaching (p=0.074). Additionally, the color assessment of all groups was statistically similar four weeks (p=0.084) and 24 weeks (p=0.118) after the beginning. Conclusion Our results indicate that adding NF/S, NA/S, NF/AC, and NA/AC desensitizers to tooth bleaching protocols reduces pain sensitivity without affecting its effectiveness.

Resumo Introdução A obtenção do resultado esperado durante o clareamento dental exige um diagnóstico correto do tipo de coloração apresentado. As causas da coloração dos dentes diferem dependendo do fator etiológico. Objetivo Avaliar a mudança de cor causada pela imersão dos dentes bovinos na solução de café durante o clareamento dentário caseiro, utilizando gel de peróxido de carbamida a 16%. Material e método Trinta e três dentes bovinos hígidos foram distribuídos em três grupos de onze dentes cada: 1 - Dentes clareados quatro horas por dia durante 21 dias; 2 – Dentes clareados quatro horas por dia durante 21 dias e imerso em solução de café imediatamente após o clareamento dentário; 3 – Dentes clareados quatro horas por dia durante 21 dias e imerso em solução de café quatro horas após o término do clareamento dentário. Imersão em café foi realizada durante 15 minutos e a cor dos dentes foi avaliada antes do início do procedimento do clareamento e após 21 dias com um espectrofotômetro intraoral. O teste Shapiro-Wilk foi utilizado para avaliar a homocedasticidade e os dados foram submetidos à análise de variância de um fator (ANOVA) e ao teste de Tukey (p <0,05). Resultado A mudança de cor observada no grupo 1 (5,76 ± 2,74)A não foi estatisticamente diferente do grupo 2 (8,83 ± 5,11)A, imerso em solução de café imediatamente após o clareamento dentário, e do grupo 3, imerso em café quatro horas após o clareamento dental (8,20 ± 3,71). Conclusão O café não interferiu nos resultados do clareamento dental, independentemente do tempo após o procedimento. Portanto, restrições alimentares não são necessárias durante o clareamento dental.

Abstract Introduction Obtaining the result expected during tooth bleaching requires a correct diagnosis of the type of staining presented. The causes of tooth staining differ depending on the etiological factor. Objective To assess the color change caused by the immersion of bovine teeth in coffee solution during at-home tooth bleaching using a 16% carbamide peroxide gel. Material and method Thirty-three sound bovine teeth were assigned to three groups of eleven teeth each: 1 – Teeth bleached (TB) four hours per day for 21 days; 2 – TB four hours per day for 21 days and immersed in coffee solution immediately after tooth bleaching; 3 – TB four hours per day for 21 days and immersed in coffee solution four hours after the end of tooth bleaching. Immersed in coffee was performed for 15 minutes and tooth color was assessed before the start of the bleaching procedure and after 21 days with an intraoral spectrophotometer. Test Shapiro-Wilk was used to assess homoscedasticity and data were submitted to one-factor Analysis of Variance (ANOVA) and Tukey’s test (p <0.05). Result The color change observed in group 1 (5.76 ± 2.74)A was not statistically different from group 2 (8.83 ±5.11)A, which was immersed in coffee solution immediately after tooth bleaching, and from group 3, which was immersed in coffee solution four hours after tooth bleaching (8.20 ±3.71)A. Conclusion Coffee did not interfere with the tooth bleaching results, regardless of the time after the procedure. Hence, diet restrictions are not necessary during tooth bleaching.