RESUMEN
OBJECTIVES: To compare the effects of replacing reinforcing barium glass particles by DCPD (dicalcium phosphate dihydrate), as opposed to simply reducing glass filler content, on composite flexural properties and degree of conversion (DC). On a second set of experiments, composites with different "DCPD: glass" ratios were exposed to prolonged water immersion to verify if the presence of DCPD particles increased hydrolytic degradation. METHODS: Two series of composites were prepared: 1) composites with total inorganic content of 50 vol% and "DCPD: glass" ratios ranging from zero (glass only) to 1.0 (DCPD only), in 0.25 increments, and 2) composites containing only silanized glass (from zero to 50 vol%). Disk-shaped specimens were fractured under biaxial flexural loading after 24 h in water. Another set of specimens of composites with different "DCPD: glass" ratios was stored in water for 24 h, 30, 60, 90 and 120 days and tested in flexure. DC was determined using FTIR spectroscopy. Data were analyzed using Kruskal-Wallis/Dunn test (flexural properties) or ANOVA/Tukey test (DC, alpha: 0.05). RESULTS: For glass-only composites, reducing inorganic content caused a linear decrease in strength. The presence of DCPD did not affect composite strength up until a "DCPD: glass" ratio of 0.5. On the other hand, materials with 0.75 and 1.0 DCPD showed significantly lower strength than the glass-only composite with 12.5 vol% filler and the unfilled resin, respectively (p < 0.001). Except for the 0.25 DCPD composite, the presence of DCPD did not contribute to increase flexural modulus. After water storage, composites containing DCPD showed higher percent reductions in properties than the control, but only in a few cases the effect was statistically significant (strength: 0.5 DCPD, modulus: 0.25 and 1.0 DCPD). DC was only marginally affected by DCPD fraction. SIGNIFICANCE: For composites with "DCPD: glass" of 0.25 and 0.5, reductions in strength were related to the lower glass content, and not due to the presence of DCPD. Flexural modulus was primarily defined by glass content. Overall, composites containing DCPD particles presented higher reductions in properties after water storage, but it remained within limits reported for commercial materials.
Asunto(s)
Calcio , Resistencia Flexional , Resinas Compuestas , Vidrio , Ensayo de Materiales , Fosfatos , Docilidad , Propiedades de Superficie , AguaRESUMEN
Objetivo: realizar uma revisão sistemática de literatura para verificar as taxas de sucesso do tratamento de dentes permanentes imaturos com periodontite apical após procedimentos tradicionais de apicificação ou de procedimentos de regeneração/revascularização pulpar. Material e Métodos: uma busca eletrônica de artigos foi executada em bancos de dados PubMed e Cochrane, usando termos médicos específicos, entre janeiro de 2000 a junho de 2015. Outras publicações presentes na seção de referência de cada artigo relavante foi analisada a partir de uma busca manual e foram acrescentadas na lista de artigos selecionados. Resultados: inicialmente, um total de 114 títulos foi identificado. Um estudo adicional foi identificado como relevantes após uma busca das listas de referência. Após o enquadramento nos critérios de inclusão e exclusão, apenas dois artigos foram selecionados. Os estudos incluídos demonstram resolução dos sinais clínicos, sintomas e radiolucência periapical para ambas as formas de tratamento. Em contrapartida os estudos foram divergentes no que diz respeito ao aumento de comprimento e espessura radicular após terapias regenerativas; enquanto um estudo apresentou dados mais favoráveis à terapia regenerativa, o outro não demonstrou diferenças entre as duas terapias testadas. Conclusão: a presente revisão sistemática indica a existência de poucos estudos comparando diretamente as duas técnicas avaliadas. Além disso, os protocolos de revascularização oferecem o potencial para tratar dentes permanentes com rizogênese incompleta, com o consequente desaparecimento dos sinais e sintomas e uma maior possibilidade de continuidade de formação radicular quando comparados aos tradicionais procedimentos de apicificação.
Objective: to perform a systematic literature review to evaluate the success rates of treatment of immature permanent teeth with apical periodontitis after traditional procedures like apexification or regeneration/pulp revascularization. Materials and Methods: an electronic search was executed in the PubMed and Cochrane databases using specific medical terms. Articles published between January 2000 and June 2015 were evaluated. Other publications in the reference section of each relevant article were analyzed in a manual search and were added to the selected articles list. Results: at first, a total of 114 titles and resumes was identified after an electronic search in both electronic databases, using a specific combination of terms and keywords. An additional study was identified as being relevant after a reference list search. After the framing in the inclusion/exclusion criteria, only two articles were selected. The included studies demonstrated resolution of clinical signs, symptoms, and periapical radiolucencies to both treatments. On the other hand, these studies were divergent in relation to increased length and root thickness after regenerative therapy; while one of the studies presented more favorable outcomes to regenerative therapy, the other one showed no differences between the two tested therapies. Conclusion: although there are few studies performing a direct comparison between conventional therapies and regenerative therapies, the present systematic review indicates that revascularization protocols offer the potential to treat permanent teeth with incomplete root formation, leading to the disappearance of the signals, symptoms, and an increased possibility of continuing root formation.
RESUMEN
The term amelogenesis imperfecta is applied to a clinically heterogeneous group of hereditary disorders that interfere with the normal development of dental enamel. These disorders cause a deficiency in the enamel's quantity and/or the quality that may result in poor dental esthetics. The purpose of this paper was to describe a case of hypoplastic amelogenesis imperfecta in an 8-year-old girl whose dissatisfaction with the appearance of her teeth led to impaired social functioning. Since the patient was in the mixed dentition stage, a temporary treatment aiming to improve dental esthetics, preserve oral function, and allow for the recovery of the patient's self-confidence was performed by a multidisciplinary team.