A high frequency of consumption of added sugars is associated with periodontal disease, independent of traditional risk factors, suggesting that this consumption pattern may contribute to the systemic inflammation observed in periodontal disease and associated noncommunicable diseases.

Since viable bacteria can persist in tooth cavities regardless of the technique used for caries removal, the objective of the present randomized clinical trial was to examine the microflora of primary teeth treated by complete or partial removal of carious dentin. Deciduous molars with acute carious lesions in the inner half of dentin and vital pulp were randomly divided into two groups of 16: complete removal, in which the carious dentin was completely removed with the help of a caries detector dye, and partial removal, in which the carious dentin was completely removed from the dentinoenamel junction and lateral walls, while the necrotic carious dentin from the cavity floor was only removed superficially. Dentin samples were obtained with a sterile No. 3 bur after caries removal and 3–6 months after protection with calcium hydroxide cement and restoration of the cavities with resin composite. The samples were stored in thioglycolate. Decimal dilutions were then prepared and seeded for the enumeration of Streptococcus spp., mutans streptococci, Lactobacillus spp. and total microorganisms. Before sealing, a larger number of microorganisms was detected in teeth submitted to partial caries removal compared to the complete removal group. However, after sealing the level of colonization was similar in the two groups for all microorganisms studied. The results suggest that persistence of bacteria does not seem to be a reason for reopening of cavities in deciduous teeth after partial caries removal.

The relationship between clinical characteristics of carious dentin and bacterial colonization after partial caries removal is not completely understood. The aim of this study was to compare microbial counts between categories of carious dentin color, consistency and humidity, and to evaluate the correlation between these characteristics and the presence of cariogenic microorganisms in deep cavities (2/3 or more of the dentin thickness) submitted to partial caries removal. Sixteen primary teeth were submitted to the removal of all carious tissue from the lateral walls of the cavity, whereas carious tissue of the pulp wall was removed superficially. Dentin in the pulp wall was classified according to color, consistency and humidity immediately after cavity preparation and 3–6 months after cavity sealing and a tissue sample was collected on the same occasion for microbiological evaluation. Before sealing, Streptococcus mutans (p = 0.033) and Lactobacillus spp. (p = 0.048) counts were higher in cavities with humid dentin compared to cavities with dry dentin. A negative correlation was observed between carious dentin consistency and S. mutans count during this phase (r_s = –0.571; p = 0.020). Arrest of dentinal caries lesions was observed after sealing, which was characterized by a reduction of bacterial counts and changes in dentin color, consistency and humidity, irrespectively of baseline dentin characteristics. The clinical characteristics of carious dentin change after the period of cavity sealing and cannot be applied as absolute indicators to limit the excavation of carious dentin when minimally invasive techniques are used.

No abstract

This in vitro study aimed to evaluate the volume of polymerization shrinkage (VS), gap (VG), and void (VV) using computerized microtomography (μCT) in bulk fill resin composites and conventional class I restorations, and to establish a correlation between these factors. Class I cavities (4 x 5 x 4 mm), C-factor = 4.2, were performed on caries-free human third molars and randomly divided into five groups (n = 6): FSI (Filtek Supreme XTE incremental insertion); FSS [(Filtek Supreme XTE single insertion(SI)]; TBF [(Tetric Bulk Fill: SI and manual filling (MF)]; SFM (Sonic Fill: SI/MF); and SFS (SonicFill: SI and sonic filling). The teeth were scanned and analyzed by μCT at T0, after filling the cavity with resin, and at T1, after polymerization for VG and VV, and for VS (T1-T0). There was statistically significant difference in VS in μCT for the FSI and FSS groups and between SFS and FSS as well as some difference in VV for FSI and bulk fill resin composites and no difference in VG between the conventional technique and bulk fill composites. Bulk fill resin composites presented similar VS and gap formation to those of incrementally inserted conventional resin composites. There is a moderate and weak positive correlation between polymerization shrinkage and gap formation and void, respectively. The final gap formation was more dependent on the initial gap than on polymerization shrinkage or void volume.

Currently, there are no studies in the literature evaluating salivary fluoride retention after small amounts of fluoride gel are applied to children's teeth. Therefore, the objective of the present study was to compare salivary retention after gel application using a toothbrush or by traditional application with trays. In this crossover study, children with active caries (n = 10) were randomized into one of the following treatment groups: a) application of fluoride gel using a tray (control), or b) application of fluoride gel with a toothbrush (treatment). After a 7-day washout period, the treatments were inverted. Unstimulated saliva samples were collected at baseline and 0.5, 5, 15, 30, 60 and 120 minutes after acidulated phosphate fluoride (APF) gel application in order to analyze fluoride retention in saliva. The area under the curve (AUC) was also calculated. There were no differences in fluoride retention after application of small amounts of APF with a toothbrush compared to traditional gel application using trays at all time points studied, and no differences in AUC were observed (Student t-test, p > 0.05). These results suggest that application of fluoride gel in children using a toothbrush can be utilized as an option rather than traditional trays, since the same salivary retention of fluoride is obtained using a lower dose.

The present study aimed to evaluates polymerization shrinkage (PS) using microcomputed tomography (μCT) and microtensile bond strength (μTBS) in bulk fill composites (BFC) and conventional class I restorations as well as the correlation between these factors. Class I cavities (4 x 5 x 4 mm), factor-C = 4.2, were created in third molars that were free of caries, which were randomly divided in 4 groups (n = 6): XTI (Filtek Supreme XTE: incremental technique); XTB (Filtek Supreme XTE: single fill technique); TBF (Tetric Bulk Fill); and SF (SonicFill). Each tooth was scanned twice in μCT: T0 was after filling the cavity with composite, and T1 was after light curing. The data were analyzed by subtracting the composite volume for each time (T1 - T0). After 1 week, the teeth were sectioned crosswise in the buccolingual and mesiodistal directions to obtain specimens with approximately 1 mm² thickness and fixed in a universal testing machine to perform μTBS. The Kruskal-Wallis and Dunn tests showed a statistically significant difference for shrinkage in µCT among the XTI and XTB and between the SF and XTB. Regarding the μTBS, all the groups differed from XTB. Bulk fill composites type presents a PS similar to that of the conventional nanoparticulate composite inserted using the incremental technique, but the bond strength was higher for the incremental group, which presented a lower number of pre-test failures when compared to BFC. No correlation was observed between the polymerization shrinkage and bond strength in the studied composites.

RESUMOO objetivo deste estudo foi realizar uma revisão crítica da literatura sobre os fatores que podem interferir nos resultados do teste de microtração de sistemas adesivos ao esmalte ou dentina. Foram utilizados trabalhos publicados nas bases de dados eletrônicas MEDLINE e BBO, em inglês, espanhol ou português, entre julho de 1994 e setembro de 2009, referências destes artigos, além de dissertações e teses disponíveis em bancos de dados eletrônicos de universidades brasileiras enfocando o estudo das variáveis que podem influenciar cada fase da execução do ensaio de microtração. A estratégia de busca incluiu os termos: microtração e teste; microtração e ensaio; microtensile e test e parameters; microtensile e test e factors; microtensile e specimen; microtracción e espécimen. Os 25 artigos selecionados demonstraram que mesmo após a padronização de parâmetros do ensaio, as alterações encontradas na dentina podem ser responsáveis pela variação do resultado. Uma maneira de reduzir esta influência seria utilizar os valores de resistência coesiva da dentina adjacente à interface adesiva como padrão de comparação, porém mais estudos são necessários. Aspectos relativos à análise dos dados devem ser levados em consideração quando se compara os estudos.Termos de indexação: Materiais dentários. Adesivos dentinários. Teste de materiais. Resistência à tração.