Researches Regarding the Improvment of Different Dental Contemporary Composite Materials Structure

Abstract

The purpose of this study was to test the structural improving that may be acquired by adding hydroxyapatite microparticles bearing or not silver nanoparticles to three different commercial products commonly used in dental practice. The practical part of this study consisted in the preparation of a common protocol of nine samples resulting from the creation of cavities and their filling similarly to the solving of different clinical situations of carious processes, extracted teeth belonging to both the anterior and the posterior area, with different architectures of the loss of dental substance. Before use, both HA and HA/AgNP have been subjected to calcination in an oven at 6000C for three hours in order to eliminate the residual organic matter. The structural changes have been studied on three types of composites known in the medical practice under the tradenames of Ceram X Duo, Swiss Tec and Herculite XRV Ultra. The structural changes materialized at the level of dentinal component are clearly visible in the SEM images recorded for each starting commercial material. Thus, the addition of HA with high polydispersity (within the range of tens of nanometers and several microns) was effective on lowering the surface rugosity and apparent macro-porosity, while enhancing the phase mixing and component cohesion, but only in the case of Ceram X Duo and Swiss Tec materials. For Herculite XRV Ultra these effects seems to be limited or even reversed, phenomenon that could be explained by the fact that this material already contains nano-fillers, and their concentration tends to saturation.