Surface characteristics and optical properties of plasma deposited films on indirect aesthetic restorative dental materials

Abstract

The aim of this study was to develop and characterize wettability, morphology, chemical composition and color of plasma-deposited thin films on the surface of dental materials. A porcelain (VM9, VITA (PC)) and two indirect composite discs (Enamic, VITA (EN) and Lava Ultimate, 3M ESPE (LU)) were used. Different methodologies of film deposition were established: plasma-enhanced chemical vapor deposition (PECVD) with HMDSO/Ar (PAr); PECVD with HMDSO/O-2 (PO2); plasma immersion ion implantation and deposition using HMDSO/Ar (PII). Surface roughness and film thickness were determined by profilometry. Contact angles were measured with a goniometer. Morphological analysis was evaluated using SEM and chemical composition was investigated by FTIR and XPS. Color differences (Delta E) were verified by a spectrophotometer. The films' thicknesses were 620 nm (PAr), 540 nm (PO2) and 70 nm (PII). Surface roughness was not changed for most of the groups. An increase in contact angles for all film groups was detected, except for LU-PII group. In PO2 films, granular structures covered the entire surface and their presence decreased in PAr and PII. Color differences maintained below 3.0. PO2 showed a silica-like and PII silicon oxycarbide-like structure and PAr presented an organic behavior. Plasma deposited thin films were developed and altered surface characteristics of restorative materials, maintaining the materials color and adequate surface roughness potentially working as a protective barrier.