ABSTRACT
BACKGROUND: The prophylactic extraction of third molars is a common practice in dental offices, but divergent opinions are found in the literature regarding the indication of this procedure. The aim of the present study was to determine the prevalence of pathological changes associated with the pericoronal tissue of asymptomatic impacted third molars that could justify prophylactic extraction. MATERIALS AND METHODS: A cross-sectional observational study was conducted in which 109 pericoronal tissues with no radiographic evidence of pathology were histopathologically analyzed. The specimens were fixed in 10% formalin, embedded in paraffin, stained with hematoxylin and eosin and analyzed individually by two pathologists. RESULT: The frequency of inflammatory infiltrate in the dental follicle of patients older than 20 years of age was significantly higher than that of younger patients (p = 0.004), demonstrating an association between inflammation in the dental follicle and patient age. The occurrence of squamous metaplasia was also greater in patients older than 20 years (p = 0.042), demonstrating that the prevalence of squamous metaplasia increases with age. A significant association was also found between inflammation and squamous metaplasia (p < 0.001). CONCLUSION: Pathological changes may be present in the dental follicle of impacted third molars even in the absence of clinical or radiographic signs of disease.
ABSTRACT
Objetivo: O objetivo deste estudo foi avaliar o efeito do condicionamento com diferentes concentrações de ácido fluorídrico (AF) na resistência de união ao cisalhamento entre cerâmica feldspática glazeada e bráquetes metálicos. Material e Métodos: Setenta e cinco blocos de cerâmica feldspática glazeada foram produzidos e distribuídos aleatoriamente em 5 grupos: Ctrl- silano; HF1- AF 1% + silano; HF3- AF 3% + silano; HF5- AF 5% + silano; HF10- AF 10% + silano (procedimento padrão: condicionamento por 1 min + lavagem + secagem + silanização). Bráquetes metálicos de incisivo central superior (Edgewise Standard) foram colados sobre a superfície da cerâmica com o uso de um sistema adesivo e resina composta fotopolimerizável (Transbond TM XT, 3M). Os espécimes foram envelhecidos por 60 dias (termociclagem: 10000x a 5-55°C; estocados em água destilada a 37°C). O teste de cisalhamento foi realizado e espécimes foram classificados quanto ao seu Índice de Remanescente Adesivo (IRA). Inspeção topográfica e análise do ângulo de contato da superfície da cerâmica condicionada foram realizados. Dados de resistência adesiva foram analisados estatisticamente usando o teste de Kruskal-Wallis, enquanto os dados de ângulo de contato foram analisados com ANOVA 1-fator e teste de Tukey (p<0.05). Resultados: Nenhuma diferença significativa foi detectada para a resistência de união entre os grupos; mas o condicionamento da superfície teve uma influência significativa sobre os resultados de ângulo de contato (p<0.00001). O grupo controle apresentou a mais alta média de ângulo de contato (61,8± 17,2°). Todos os espécimes apresentaram falhas adesivas na interface cerâmica-resina. Conclusão: As concentrações de AF testadas não influenciaram significativamente a resistência de união de bráquetes metálicos aderidos na superfície de cerâmica feldspática glazeada
Objective: The aim of this study was evaluate the effect of etching with different hydrofluoric acid (HF) concentrations on the shear bond strength between glazed feldspathic ceramic and metal brackets. Material and Methods: Seventyfive blocks of glazed feldspathic ceramic were produced and randomly allocated to 5 groups: Ctrl- silane application only; HF1- HF1%+silane; HF3- HF3%+silane; HF5- HF5%+silane; HF10 HF10%+silane (standard procedures: etching for 1 min + washing + drying + silanization). Metal brackets for upper central incisors (Edgewise Standard) were bonded on the ceramic surface with the use of an adhesive system and light-cured composite resin (TransbondTM XT, 3M). The specimens were aged for 60 days (thermocycling: 10000x at 5-55 °C; stored in distilled water at 37°C). Shear testing was performed, and specimens were classified for their AdhesiveRemnant-Index (ARI). Topographical inspectionand contact angle analysis of the etched ceramic surfaces were performed. Data were statistically analyzed using the non-parametric Kruskal-Wallis test. One-way ANOVA and post-hoc Tukeys tests were applied to the contact angle data (p<0.05). Results: No significant difference was detected between the shear bond strength of the groups; but surface etching had a significant influence on the contact angle results (p<0.00001). The control group presented the highest mean contact angle (61.8±17.2°). All specimens showed adhesive failure at the resin ceramic interface. Conclusion The tested HF concentrations did not significantly influence the obtained shear bond strength of metal brackets adhered to glazed feldspathic ceramic surfaces.
