Antibacterial effect and biocompatibility evaluation of glow discharge plasma treatment on titanium surface: in vitro and in situ study

Abstract

The titanium surface treatment with glow-discharge plasma has been used for surface cleaning, reduction of corrosion and changes on the adjacent bone tissue. However, its antibacterial effect, as well as its biocompatibility with gingival tissue cells, has not been previously evaluated, especially considering the abutments. Therefore, the objective of this study is to evaluate the antibacterial effect and biocompatibility of glow-discharge plasma treatment on titanium surface, using in vitro and in situ models. Commercially pure titanium discs (cpTi) will have their surface characterized and subjected to the following treatments: negative control group (use of cpTi discs without surface treatment); and experimental group (cpTi discs with surface treatment by glow-discharge plasma. Three experiments will be conducted. 1) in vitro, blind study, for assessing the biofilm adhesion and formation on cpTi discs. The formation of biofilm (7 days) will be performed considering as inoculum saliva of volunteers. 2) in situ, double blind study, where the volunteers will use during 7 days a palatal appliance containing 4 discs of cpTi (2 treated with control group and 2 experimental group), covered by a plastic mesh to allow the accumulation of biofilm. The biofilm formed will be collected for analysis of total amount of microorganisms via Real Time PCR and characterization of biofilm using confocal laser microscope and scanning electron microscope (Experiment 1 and 2). 3) in vitro study of the culture of fibroblast cells on cpTi discs. After an incubation period, the cell viability and morphology, gene and collagen expression will be evaluated. Groups will be statistically compared using appropriate tests. (AU)