Adhesive Interface and Chemical Composition of Nanoparticulate Composite Universal Injectable

Objectives: Determine the adhesion-adaptation interface and chemical composition of composite nanoparticulate universal injectable in Class 1 occlusal cavity.
Methods: 14 human third molars with class 1 occlusal cavity in deep dentin with a contour of 3.5x3.5x3.5mm standardized were used. After, in each cavity, G-Bond adhesive (GB), applied 10 seconds, evaporated the solvent and photopolimerized. G-ænial Universal Injectable (UG), in thicknesses 2.0 mm, were applied. The GB and UG was photopolymerized for 20 seconds from the occlusal surface in each of the layers with LED lamp with an intensity of 1400 mW/cm2. Teeth were cut in a bucco-lingual direction in serial plates and a fine polishing with diamond paste with 0.5μm particles. Confocal Laser Scanning Microscope was used and level of the interfaces, of pulp and lateral walls, were quantified. These values were subjected to statistical analysis of variance (ANOVA). For the chemical quantification of the biomaterial, an Emission Scanning Electron Microscope with detector of X-ray Microanalysis was used. The samples were subjected to critical point drying and metallized with a 0.02nm gold layer.
Results: a) interfaces were measured on the pulp wall with values of 0.03µm, while in the buccal and lingual walls, the values were zero or nulls; however, the differences were not statistically significant with p<0.05. b) UG presented a composition in Wt% of C: 35.07; O: 30.01; Si: (Si0₂) 16.98; Al: (Al₂0₃) 3.33; Ba: (BaF₂) 14.61; c) The structure of UG presented ultrafine inorganic particles with silane of total coverage, with a value of 72.43% of Wt%, values that influence decrease interfaces.
Conclusions: 1) The adhesive interfaces with enamel and dentin had zero or nulls values on the laterals walls and minimal on the pulp walls. 2) It is important that the thickness of its layer does not exceed in its intracavitary, layer thicknesses greater than 2.0mm.