The aim of this study was to evaluate the microhardness and surface roughness of composite resins immersed in alcoholic beverages. Three composite resins were used: Durafill (Heraeus Kulzer), Z250 (3M-ESPE) and Z350 XT (3M-ESPE). The inital surface roughness and microhardness were measured. The samples were divided into four groups (n=30): G1-artificial saliva; G2-beer; G3-vodka; G4-whisky. The samples were immersed in the beverages 3× a day for 15 min and 30 days. The surface roughness and microhardness assays were repeated after immersion period. The data were statistically analyzed by two-way ANOVA and Tukey-HSD test (p<0.05). Surface roughness increased for all composite resins immersed in beer and whisky. Microhardness of all groups decreased after immersion in alcoholic beverages. The effect of these beverages on dental composites is depended upon the chemical composition, immersion time, alcohol content and pH of solutions.

The aim of this study was to measure and compare the dimensional accuracy of stone casts of a partially edentulous mandibular arch made by two condensation silicones, two addition silicones and three impression techniques (1-step putty/light-body, 2-step putty/light-body and monophase technique). A partially edentulous standard stainless steel mandibular arch cast was obtained with reference points on the permanent mandibular right and left canines, and permanent mandibular right and left second molars. The anteroposterior distances (between the mandibular left canine and second molar and between the mandibular right canine and second molar) and transverse distances (between the mandibular left and right canines and between the mandibular left and right second molars) of stainless steel cast were measured by a microscope at 30× magnification and 0.5 µm accuracy. All impressions were made with condensation or addition silicones. The 1- and 2-step putty/light-body impressions were accomplished with putty and light-body materials and the monophase impressions with light-body material only. After the impression procedures, accuracy of each material and technique was assessed measuring the stone casts poured (n=5) from the impressions, by the same microscope. The differences between the values of stone cast and stainless steel cast were calculated, presented as percentages and analyzed statistically by two-way ANOVA and the means compared by Tukey's test (α=0.05). All distances measured on stone casts showed altered dimensions with significantly negative linear changes (shrinkage) as compared to those of the stainless steel cast. The stone casts made from the addition silicones were dimensionally more accurate. No differences were found among the impression techniques.

The objective of this study was to evaluate the influence of a cola soft drink (CSD) and coffee on the microhardness and surface roughness of composite resin. Fifty cavities were prepared on the vestibular surface of bovine incisors and restored with nanoparticulate resin. The teeth were divided into five groups (n = 10): group A (control), immersion in artificial saliva (AS) for 14 days; group B, immersion in coffee for 15 min (3×/day) for 7 days followed by immersion in AS for another 7 days; group C, immersion in CSD for 15 min (3×/day) for 7 days followed by immersion in AS for another 7 days; group D, immersion in AS for 7 days, immersion in coffee for 15 min (3×/day) for 7 days; group E, immersion in AS for 7 days, immersion in CSD for 15 min (3×/day) for 7 days. After the immersion periods the specimens were analyzed for their microhardness and surface roughness. The data were subjected to analysis of variance (ANOVA) followed by t-test with 5% significance. Group A presented the highest average microhardness and lowest surface roughness, so it was possible to conclude that the consumption of CSD and coffee alters the microhardness and surface roughness of new restorations.

The type IV dental stone is widely used for the fabrication of dyes and master casts for fixed and removable partial prostheses. It is typically normal to wait at least 24 hours for the casts to dry prior to beginning the laboratory procedures. The waiting time has been shown to be greatly reduced by using microwave drying.ObjectiveThis study evaluated the influence of drying techniques at room temperature and microwave oven on the linear dimensional change, compressive strength and detail reproduction in type IV dental stones. Material and MethodsThree type IV dental stone brands were selected; Elite Rock, Shera Premium and Durone IV. Two different drying protocols were tested in 4 groups (n=10); G1 - room temperature (25±4ºC) dried for 2 hours; G2 - room temperature dried for 24 hours; G3 - room temperature dried for 7 days and G4 - microwave oven dried at 800 W for 5 minutes and after 2 hours at room temperature. After drying, the samples were assayed for dimensional charges. The sample surface was submitted to the ImageTool 3.0 software for compressive strength in a universal testing machine with a cell load of 50 KN at a crosshead speed of 0.5 mm/minutes and the detail reproduction was analyzed with a stereomicroscope at 25x magnification. The statistical analysis of the linear dimensional change and compressive strength data were conducted by the ANOVA test followed by the Tukey test (p<0.05). Detailed reproduction values were reported in percentages. ResultsFor the compressive strength test, Elite Rock and Durone IV did not present significant differences between G2 and G4, while Shera Premium did not present differences between G3 and G4. The best reproduction levels were observed for G3. ConclusionsDental stone microwave oven drying showed a linear dimensional change similar to after room temperature drying for 24 hours and 7 days. The compressive strength of the stone dried in the microwave oven was similar to those dried at room temperature for 24 hours, with the exception of Shera Premium, which had similar results for microwave and room temperature drying for 7 days. For the microwave drying method the detail reproduction levels for samples dried at room temperature for 24 hours and 7 days were similar, except for the Durone IV.

This in vitro study evaluated the marginal gap at the composite tooth/resin interface in class V cavities under the influence of two insertion techniques and a curing system by means of atomic force microscopỹ AFM!. Forty enamel and dentin cavities were prepared on the buccal surface in bovine teeth with quadratic forms measuring 2 mm ϫ 2 mm and depth of 1.5 mm. The teeth were then divided into four groups: group A, 10 cavities were restored in one increment, light cured by halogen light; group B, 10 cavities filled with bulk filling, light cured by the light emitting diodes~LED!; group C, 10 cavities were restored by the incremental technique, light cured by halogen light; group D, 10 cavities were restored by the incremental technique, light cured by the LED. The teeth underwent the polishing procedure and were analyzed by AFM for tooth/ restoration interface evaluation. The data were compared between groups using the nonparametric KruskallWallis and Mann-Whitney tests~p , 0.05!. The results showed a statistically significant difference between groups A and B and groups A and C. It was concluded that no insertion and polymerization technique was able to completely seal the cavity.

This study presents how the tooth whitening affects the bond strength and fracture type of three distinct adhesivesa conventional, a self-etching, and a universal adhesivein enamel. Health bovine incisors were prepared by flattening the labial surface; part of these teeth was submitted to whitening treatment with a peroxide-based product (WhiteGold Office © 35%). The Single Bond © , AdheSE © , or Single Bond Universal © adhesive system were used to adhere a block of restorative resin to the flat surface of the teeth. Sticks measuring 10x1x1 mm were prepared and used in microtensile tests; they were also employed to examine the type of fracture. The results are analyzed with a two-way ANOVA. For both whitened and non-whitened specimens, the adhesive systems did not give statistically different bond strength values. However, the fracture shape (classified into four types) varied from a cohesive enamel type fracture for the whitened samples to a predominantly cohesive resin type fracture for the non-whitened teeth. Therefore, the whitening procedure has exerted a weakening effect on enamel even after 21 days post-treatment.

Objetivo: Esclarecer por meio de uma revisão integrativa se produtos contendo carvão ativados são eficazes e apresentam efeitos adversos. Métodos: Uma busca foi realizada nos bancos de dados PubMed, MEDLINE, Scopus e Scielo, utilizando o operador booleano “AND” com a combinação dos termos MesH: Activated Charcoal, Toothpastes e Mouthwashes, em português Carvão Ativado, Pastas Dentárias e Enxaguatórios Bucais, inserido artigos publicados em língua inglesa e portuguesa até junho de 2021. Resultados: Inicialmente, foram identificados 5.575 artigos, e após aplicação dos critérios de elegibilidade e excluindo comentários, resumos expandidos, enciclopédias, capítulos de livros, conferências, correspondência, discursões, comunicados, estudos repetidos e estudos não disponíveis na íntegra chegou-se a 8 artigos elegíveis para esse estudo. Considerações finais: Os poucos dados clínicos encontrados supõem-se que que os dentifrícios a base de carvão ativado possuem pouco ou nenhum efeito clareador. Em contraparte, vários estudos comprovam os efeitos contra prudentes do uso de carvão ativado na cavidade oral, como, o aumento do risco de danos ao esmalte devido à abrasividade das partículas de carvão, risco de sensibilidade dental e risco de deformidades do periodonto.

Objetivos: Considerando que os dentes decíduos são mais propensos ao desenvolvimento de cárie dentária, este estudo teve como objetivo comparar o efeito de diferentes técnicas de aplicação de selante de fóssulas e fissuras, isoladas ou associadas, na microinfiltração de esmalte em molares de dentes decíduos. Materiais e métodos: dentes molares decíduos foram sele­cionados (n = 8) e receberam os seguintes tratamentos: 1) grupo controle: condicionamento ácido + selante; 2) ar abrasivo + condicionamento ácido + selante; 3) condicionamento ácido + adesivo + selante; 4) ar abrasivo + condicionamento ácido + adesivo + selante. Após o tratamento, os dentes foram imersos em água destilada a 37 °C por sete dias e então submetidos a termociclagem de 350 ciclos de banhos de água fria (5 °C) e quente (55 °C), com 30 segundos cada exposição. Posterior­mente, os dentes foram cobertos com um verniz – deixando exposta apenas a área selada, estendida por 1 mm –, imperme­abilizados com resina epóxica e imersos em solução de azul de metileno por 48 horas a 37 °C. Em seguida, os dentes foram seccionados vestíbulo-lingualmente e avaliados microscopicamente (aumento de 40×). Os resultados foram submetidos aos testes de Kruskal-Wallis e de Mann-Whitney (p < 0,05). Resultados: os grupos que receberam o adesivo antes da apli­cação do selante apresentaram o menor índice de microinfiltração. O grupo que recebeu ar abrasivo mais condicionamento ácido antes do selante mostrou microinfiltração mais extensa. Conclusões: nenhuma das técnicas utilizadas evitou comple­tamente a microinfiltração, entretanto a aplicação de adesivo pode ser a mais indicada.