EFEITOS DA BENZOFENONA NAS PROPRIEDADES FÍSICO-QUÍMICAS DE RESINAS COMPOSTAS EXPERIMENTAIS COM DIFERENTES FOTOINICIADORES

O objetivo foi avaliar o potencial da benzofenona como fotoiniciador alternativo no grau de conversão (GC), densidade de ligações cruzadas (DLC), sorção de água (Ws) e solubilidade (S) de resinas compostas experimentais. Para isso, foram elaboradas quatro resinas com as mesmas concentrações de BisGMA, TEGDMA e partículas de carga, diferenciando apenas os fotoiniciadores: CQ/EDAB - 0,5% Canforoquinona + 1% EDAB (etil-dimetialmino benzoato, amina terciária), PPD- 2% PPD (1-fenil-1,2-propanodiona), PPD/EDAB – 2% de PPF e 4% EDAB, e BENZ - 1% de benzofenona (n,n-dietilamino) + 2% EDAB. Amostras cilíndricas foram preparadas e fotopolimerizadas com luz halógena (450 mW/cm2) por 40 segundos e foi avaliado o GC (n=3) com espectroscopia Micro Raman através dos picos 1608/1637 cm-1. A DLC (n=5) foi testada por microdureza antes e após imersão em etanol absoluto por 48h. Ws (n=5) e S (n=5) avaliado de acordo com a ISO 4049. Os resultados foram analisados com ANOVA e teste de Tukey (

In Vitro and In Vivo Efficacy of New Composite for Direct Pulp Capping.

Objectives To investigate physicochemical properties, dentin bonding, cytotoxicity, and in vivo pulp response of experimental self-adhesive composites tailored to direct pulp capping. Materials and Methods Experimental composites were prepared with beta-tricalcium phosphate and hydroxyapatite nanoparticles adsorbed with simvastatin and glutathione added at 0% (control resin), 1 wt% (Res 1%), and 10 wt% (Res 10%). A commercial light-curable calcium hydroxide (Ca(OH)2) (Ultra-Blend Plus) was used as control material. The physicochemical properties investigated were flexural strength and modulus, calcium release, and degree of conversion. Dentin bonding was assessed by the push-out test. Proliferation and cell counting assays were performed to evaluate in vitro cytotoxicity using fluorescence microscopy. In vivo pulp capping was performed on molars of Wistar rats, which were euthanized after 14 days and evaluated by histological analysis. Results No statistical difference was observed in flexural strength and cell viability (p > 0.05). Res 10% presented higher modulus than control resin and Ca(OH)2. Also, Res 10% attained statistically higher degree of conversion when compared to other experimental composites. Ca(OH)2 showed higher calcium release after 28 and 45 days of storage, with no statistical difference at 45 days to Res 10%. All experimental composites achieved significantly higher bond strength when compared to Ca(OH)2. While no significant difference was observed in the cell proliferation rates, resins at lower concentrations showed higher cell viability. In vivo evaluation of pulp response demonstrated no pulp damage with experimental composites. Conclusions The experimental composite investigated in this study achieved adequate physicochemical properties with minor in vivo pulpal inflammation and proved to be a valuable alternative for direct pulp capping