A scanning electronic microscopy study of the action of different desensitizing agents on bovine dentin

This study sought to use scanning electronic microscopy (SEM) to evaluate the dentinal tubule occlusion potential of different desensitizing agents. Ten slices of bovine dentin were divided into six fragments, cleaned (using ultrasound), and etched for 15 seconds with a 35% phosphoric acid solution. All but one of the groups received a different desensitizing agent; the sixth group served as a control and received no additional treatment. After the agents were applied, the dentin specimens were analyzed by SEM and scores were assigned based on the extent of tubular obliteration. Only three agents demonstrated tubular sealing that was significantly different from that of the control group.

Influence of desensitizing agents on the microshear bond strength of adhesive systems to dentin.

The aim of this study was to evaluate the effect of desensitizing agents on the micro-shear bond strength of adhesive systems to dentin. Forty bovine teeth were divided into 8 groups (n=5): G1--Single Bond (SB); G2--GH.F + SB; G3-- Desensibilize + SB; G4--essensiv + SB; G5 --ingle Bond 2 (SB2); G6--H.E + SB2; G7--esensibilize + SB2; G8--Dessensiv + SB2. In all of the groups, the desensitizing agents were applied after phosphoric acid etching and before the dentin adhesive application. Z250 composite resin tubes were bonded on the treated surface. After 24 hours, the teeth were tested in a universal machine. Data were submitted to ANOVA and Tukey's test (5%). The results showed that the groups where Desensibilize and Dessensiv were applied exhibited smaller bond strength values.

Lesões Cervicais Não Cariosas

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

Effects of cement-curing mode and light-curing unit on the bond durability of ceramic cemented to dentin

The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid/60s and silanized. The dentin was treated with37% phosphoric acid/15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement/RC curing type(dual-and photocured), light-curing unit (halogen light/QTH and LED), and storage conditions (dry and storage/150 days + 12,000 cycles/thermocycling). All blocks were stored in distilled water (37°C/24h) and sectioned (n = 10): G1-QTH + RC Photo, G2-QTH + RC Dual, G3-LED + RC Photo, G4-LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC), and data were statistically analyzed by ANOVA and Tukey's test (5%). The bond strength values (MPa) were: G1-12.95 (6.40)ab; G2-12.02 (4.59)ab; G3-13.09 (5.62)ab; G4-15.96 (6.32)a; G5-6.22 (5.90)c; G6-9.48 (5.99)bc; G7-12.78 (11.30)ab; and G8-8.34 (5.98)bc. The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength betweenceramic cemented to dentin when the photocured cement was used, and only after aging (LED>QTH). There was no difference between the effects of dual-and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.

Permeabilidade dentinária e erosão dentário: Avaliação de diferentes substâncias ácidas e agentes dessensibilizantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hipersensibilidade dentinária cervical: em busca de um tratamento eficaz

The knowledge of the etiology of any disease or condition is paramount to a safe and effective treatment. This literature review aims to show some options to treat dentine hypersensitivity (HSDC). The loss of cervical enamel and cementum exposure of tubules leads to a painful condition and patient discomfort, called HSDC. This loss of tooth structure occurs due to formation of cervical lesions in cases of gingival recession, abrasion, erosion, or abfraction by the association of two or more factors. Some treatments are not effective, but there are effective therapies, such as: application of ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, solutions of calcium phosphate, adhesives and Bonding procedures. Therefore, the identification and removal of etiological factors is essential to successful treatment of HSDC normally associated to tubules obliterate and consequent reduction of fluid motion within the dentin.

In Situ Effect of Dentifrices Associated to CO2 Laser in the Permeability of Eroded Root Dentin

Objective: The aim of this study was to evaluate, through a crossover 2 x 2 in situ trial, the effect of a desensitizing dentifrice associated with CO2 laser irradiation to control the permeability of eroded root dentin. Background data: Facing the increased prevalence of erosive lesion and the need for preventive means to control painful symptoms related to them. Methods: Eighty slabs of bovine root dentin were subjected to initial erosive challenge (citric acid 0.3%, 2 h), followed by a remineralizing period in artificial saliva (24 h). Specimens were then divided according to dentin treatment: desensitizing dentifrice, desensitizing dentifrice + CO2 laser, fluoride anticavity dentifrice. and fluoride anticavity dentifrice + CO2 laser. After a 2-day lead-in period, 10 volunteers wore an intraoral palatal appliance containing four root dentin slabs, in two phases of 5 days each. During the intraoral phase, one side of the appliance was immersed in 0.3% citric acid, and the opposite side was immersed in deionized water, four times a day. One hour after the immersions, all specimens were brushed with dentifrice slurry provided by the researcher. After a 7-day washout period, volunteers were crossed over on the different dentifrice group. Each phase having been completed, the specimens were evaluated for permeability through an optical microscope. Results: Data were analyzed using ANOVA and no significant difference (p = 0.272) was found between the surface treatments performed on bovine root dentin. Conclusions: It can be concluded that fluoride anticavity or desensitizing dentifrice, regardless of the association with the CO2 laser irradiation, was able to control the permeability of eroded root dentin.