Experimental pastes containing niobophosphate and 45S5 bioactive glasses for treatment of dentin hypersensitivity: dentin permeability and tubule obliteration.

OBJECTIVES: This study tested the ability of bioactive pastes containing niobophosphate and 45S5 glasses to reduce dentin permeability and to obliterate dentinal tubules, as a mean of reducing human dentin hypersensitivity. MATERIALS AND METHODS: Experimental pastes with concentrations of 10, 20, and 30 wt% of two bioactive glasses (45S5 or niobophosphate [NbG]) were formulated. A paste without bioactive glass (placebo) and a commercial paste (Nano P, FGM) were used as controls. Forty dentin disc specimens were obtained from caries-free extracted third human molars and divided in 8 groups (n = 5). Percentage of permeability (%Lp) was assessed in a dental permeability machine considering hydraulic conductance, immediately after pastes application and at day 7, day 14, and day 21. The precipitates formed on the surface of the dentin discs (and dentinal tubules) were analyzed by SEM/EDS and micro-Raman spectra. Data of dentin permeability (%) 2-way repeated-measures (ANOVA) and Holm-Sidak post-tests (α = 0.05). Dentinal tubule obliteration was visually (and elemental) evaluated and descriptively reported. RESULTS: The experimental bioactive glass pastes containing NbG and 45S5, regardless of the concentration, reduced dentin permeability in comparison with pastes without bioactive glasses (P < 0.05). The formulated placebo and commercial paste did not reduce permeability over time (P < 0.05). SEM/EDS and micro-Raman analyses showed that both type of bioactive pastes (NbG or 45S5-based) presented mineral precipitates obliterating the dentinal tubules at day 21. NbG seems to offer a better initial effect than 45S5, while at 21 days there is no difference between both glasses. CONCLUSION: Experimental bioactive pastes containing NbG and 45S5 (at concentrations of 10%, 20%, or 30%) have potential to reduce dentin permeability (over time) in comparison with pastes without bioactive glasses; and this occurs on behalf of obliteration of dentinal tubules by microparticle and precipitate formation. CLINICAL RELEVANCE: Bioactive pastes containing NbG and 45S5 may benefit patients presenting dentin hypersensitivity, because these pastes can start acting fast after application and maintain their action up to 21 days.

Clinical performance of a micro invasive treatment based on demineralization-remineralization for dental fluorosis: case report

Introduction: Dental fluorosis manifests clinically as white to brown spots on the enamel teeth that were exposed to excessive fluoride during the formation process. Esthetic treatments were described in the literature to reduce or eliminate the fluorotic stains on the enamel surface. Objective: The aim of this study is to present an alternative treatment for fluorosis-stained teeth. Case report: This case report describes the clinical performance of a treatment of a 12-year-old male patient whose teeth presented moderate fluorosis. This treatment is based on tooth demineralization and remineralization. The material has an acid phase made by hydrochloric acid with tricarboxylic acid, and an alkaline phase made by Calcium Hydroxide. Results: This pain less and fast treatment presented good results. The treatment eliminated the spots during the follow-up and preserved most of the dental structure, improving the appearance of the patient's teeth. Conclusion: The appearance of the treated enamel showed a surface almost completely free of fluorotic stains, demonstrating the satisfactory results of this treatment.

Introdução: A fluorose dentária manifesta-se clinicamente como manchas brancas a marrons no esmalte de dentes expostos ao excesso de flúor durante o processo de formação. Tratamentos estéticos foram descritos na literatura para reduzir ou eliminar as manchas fluoróticas na superfície do esmalte. Objetivo: Apresentar uma alternativa de tratamento para dentes manchados por fluorose dentária. Relato do caso: Este relato de caso descreve o desempenho clínico do tratamento para dentes com fluorose moderada em um paciente de 12 anos. Esse tratamento foi baseado numa técnica de desmineralização e remineralização do dente. O material possui uma fase ácida composta por ácido clorídrico com ácido tricarboxílico, e uma fase alcalina composta por Hidróxido de Cálcio. Resultados: Observou-se que esse tratamento, sem dor e rápido, apresentou resultados satisfatórios, pois eliminou as manchas durante o acompanhamento. Além disso, preservou ao máximo a estrutura dentária, beneficiando o paciente com uma melhor aparência dos seus dentes. Conclusão: O aspecto do esmalte tratado mostrou uma superfície quase sem manchas fluoróticas, demonstrando resultados satisfatórios deste tratamento.