Dentine microhardness after different methods for detection and removal of carious dentine tissue

There are several methods for identifying carious dentinal tissue aiming to avoid removal of healthy dentinal tissue. OBJECTIVES: The purpose of this study was to test different methods for the detection of carious dentinal tissue regarding the amount of carious tissue removed and the remaining dentin microhardness after caries removal. MATERIAL AND METHODS: The dentin surfaces of 20 bovine teeth were exposed and half of the surface was protected with nail polish. Cariogenic challenge was performed by immersion in a demineralizing solution for 14 days. After transverse cross-section of the crown, the specimens were divided into four groups (n=10), according to the method used to identify and remove the carious tissue: "Papacárie", Caries-detector dye, DIAGNOdent and Tactile method. After caries removal, the cross-sectional surface was included in acrylic resin and polished. In a microhardness tester, the removed dentin thickness and the Vickers microhardness of the following regions were evaluated: remaining dentin after caries removal and superficial and deep healthy dentin. RESULTS: ANOVA and Tukey's test (α=0.05) were performed, except for DIAGNOdent, which did not detect the presence of caries. Results for removed dentin thickness were: "Papacárie" (424.7±105.0; a), Caries-detector dye (370.5±78.3; ab), Tactile method (322.8±51.5; bc). Results for the remaining dentin microhardness were: "Papacárie" (42.2±10.5; bc), Caries-detector dye (44.6±11.8; abc), Tactile method (24.3±9.0; d). CONCLUSIONS: DIAGNOdent did not detect the presence of carious tissue; Tactile method and "Papacárie" resulted in the least and the most dentinal thickness removal, respectively; Tactile method differed significantly from "Papacárie" and Caries-detector dye in terms of the remaining dentin microhardness, and Tactile method was the one which presented the lowest microhardness values

Interaction effect of Nd:YAG laser and universal adhesive system for dentin sealing

To evaluate the influence of the association of the universal adhesive system to different energy densities of the Nd:YAG laser on the hydraulic conductance of dentin. Fifty bovine dentin discs were made. The samples were stratified into four groups (

The Multiple Origins of Roe Deer Populations in Western Iberia and Their Relevance for Conservation

The roe deer (Capreolus capreolus) is native and widespread in Europe and its phylogeography has been clarified in the last decades. Southern peninsulas are considered as reservoirs of genetic diversity and the source for the recolonization of Europe after the last glacial maximum. Even though roe deer populations have been genetically characterized, there is a major knowledge gap about the populations at the western edge of its distribution. To fill this caveat, and based on mitochondrial and nuclear DNA data, we aim to: (i) characterize the genetic diversity and structure of roe deer in western Iberia; (ii) clarify the origins and phylogeographical affinities of these populations, namely the relict population from Peneda Gerês National Park (PNPG, Portugal) and the likely allochthonous populations from central and south (CS) Portugal; (iii) discuss the implications of our findings for the management and conservation of the roe deer. Three major genetic clusters were inferred based on nuclear genotypes and were structured in a similar way as the three major mtDNA clades present in Iberia. Patterns inferred with nuclear markers confirmed PNPG as a relict population. Roe deer from CS Portugal share haplotypes with Central Europe rather than with other western Iberian populations, confirming its mainly allochthonous origin. Our results highlight western Iberia as a diversity hotspot for roe deer. We highlight the role of intraspecific genetic diversity as a source of resilience against ongoing global changes; the need for transboundary management and the importance of genetic data to inform management and conservation. When considered, repopulation or translocation measures should follow the IUCN Law of Reintroductions and meticulously conducted in order to preserve the genetic heritage of the species

Shear Bond Strength of Orthodontic Brackets Fixed with Remineralizing Adhesive Systems after Simulating One Year of Orthodontic Treatment

The objective of this study is to assess, in vitro, the shear bond strength of orthodontic brackets fixed with remineralizing adhesive systems submitted to thermomechanical cycling, simulating one year of orthodontic treatment. Sixty-four bovine incisor teeth were randomly divided into 4 experimental groups (n=16): XT: Transbond XT, QC: Quick Cure, OL: Ortholite Color, and SEP: Transbond Plus Self-Etching Primer. The samples were submitted to thermomechanical cycling simulating one year of orthodontic treatment. Shear bond strength tests were carried out using a universal testing machine with a load cell of 50 KgF at 0.5 mm/minute. The samples were examined with a stereomicroscope and a scanning electron microscope (SEM) in order to analyze enamel surface and Adhesive Remnant Index (ARI). Kruskal-Wallis and Mann-Whitney (with Bonferroni correction) tests showed a significant difference between the studied groups (p<0.05). Groups XT, QC, and SEP presented the highest values of adhesive resistance and no statistical differences were found between them. The highest frequency of failures between enamel and adhesive was observed in groups XT, QC, and OL. Quick Cure (QC) remineralizing adhesive system presented average adhesive resistance values similar to conventional (XT) and self-etching (SEP) adhesives, while remineralizing system (OL) provided the lowest values of adhesive resistance

Anti-erosion potential of fluoride solutions associated with aminomethacrylate copolymer: in situ randomized crossover study

The anti-erosion potential of fluoride solutions associated with aminomethacrylate (AMC) was evaluated in the presence of acquired pellicle on enamel and dentin. It is concluded that AMC was able to increase the anti-erosion potential of fluoride solutions in the presence of acquired pellicle

Microdureza de restaurações de resina composta expostas a agentes clareadores e coca cola

The purpose of this study was to evaluate the effect of 3 bleaching agents and a carbonated soft drink on composite resin restorations microhardness.. Forty fresh bovine incisive teeth were used. Next, they were embedded in acrylic resin, exception made to test facial surfaces, where standardized cavity preparations were carried out and restored composite resin ( Palfique Estelite –Toduyama). After samples were divided into 4 groups, baseline microhardness measurements were taken with a microdurometer (Future Tech – FM 700) ,that were used as experimental controls. Group 1: 10% carbamide peroxide (Whiteness Perfect – FGM) Group 2: soft drink Coca-Cola Group 3: 37% carbamide peroxide gel (Whiteness Super – FGM Group 4 35% hydrogen peroxide (Whiteness HP – FGM), Data were submitted to ANOVA and Tukey’s. Conclusions were that bleaching agents and Coca-Cola did not alter composite resin microhardness.O objetivo deste estudo foi avaliar os efeitos de três agentes clareadores e uma bebida carbonatada, à base de cola, sobre a microdureza de restaurações de resina composta. Foram utilizados quarenta dentes incisivos bovinos embutidos em resina acrílica, nas superfícies vestibulares foram realizados preparos cavitários padronizados e restaurados com resina composta (Palfique Estelite – Tokuyama). As amostras foram avaliadas em microdurômetro (Future Tech FM 700) após a divisão em quatro grupos, uma leitura inicial da microdureza serviu como controle do experimento. Grupo 1: peróxido de carbamida a 10% (Whiteness Perfect – FGM) Grupo 2: refrigerante Coca-Cola Grupo 3: peróxido de carbamida a 37% (Whiteness Super – FGM), Grupo 4: peróxido de hidrogênio a 35% (Whiteness HP – FGM). Os dados foram submetidos aos testes estatísticos ANOVA e Tukey. Conclui-se que os agentes clareadores e a Coca Cola não alteraram a microdureza da resina composta durante os 14 dias de desafio químico

EROSÃO DENTAL: INFLUÊNCIA DO FOSFATO DE CÁLCIO, MATERIAIS RESINOSOS E IONOMÉRICOS NA PERMEABILIDADE DENTINÁRIA

Introdução: Com o aumento do consumo de dietas ácidas, desajustes oclusais e envelhecimento da população, há um aumento de lesões dentais não cariosas e hipersensibilidade dental. Objetivo: Avaliar, in vitro, por meio do teste da condutância hidráulica, a influência de fosfato de cálcio, materiais resinosos, resinosos-ionoméricos na permeabilidade dentinária, e seu efeito após desafio erosivo. Métodos: Foram confeccionados 40 discos de dentina bovina com 6mm de diâmetro e 1mm de espessura. A condutância hidráulica inicial foi medida, após a remoção da smear layer e abertura tubular, com o auxílio do aparelho de permeabilidade dentinária (ODEME). Os espécimes foram divididos estratificadamente em 4 grupos experimentais (n=10): Single Bond 2 (3M), Clinpro XT Varnish (3M), Nano P Dessensibilize (FGM), e Controle (sem tratamento). Estes foram imersos em água deionizada (37±1°C) por 24. Mensurações da condutância hidráulica foram realizadas após os tratamentos e após a realização do desafio erosivo. Foram calculadas as variações percentuais (%P) para os valores de permeabilidade póstratamento (%PPT) e pós-desafio erosivo (%PPDE). Os testes ANOVA e pos-hoc Scheffe analisaram (%PPT), e Test-T pareado para as condições (%PPT e %PPDE) (p90%), e o agente dessensibilizante Nano P apresentou significativa redução da permeabilidade quando comparada ao grupo sem tratamento (p<0,001). Os tratamentos realizados foram resistentes ao desafio erosivo. Conclusão: Os sistemas à base de componentes resinosos, ionoméricos e fosfafo de cálcio reduzem a permeabilidade dentinária, e apresentam resistência ao desafio erosivo.Descritores: Permeabilidade da Dentina. Sensibilidade da Dentina. Adesivos Dentinários