Effects of an air-powder abrasive system on plasma-sprayed titanium implant surfaces: an in vitro evaluation

The purpose of this study was to conduct an in vitro evaluation of the effects of an air-powder abrasive system, commonly used in clinical dentistry for periodontal maintenance, on the surfaces of plasma-sprayed titanium dental implants. Twenty-eight plasma-coated titanium implant specimens were divided into a sterile water-treated control group and an air-powder-abrasive-treated test group. All specimens were subjected to three different in vitro testing conditions and post-treatment evaluations by scanning electron microscopy (SEM): (1) Topographical features of implant surfaces were studied before and after direct exposure to the abrasive; (2) biocompatibility of treated implant surfaces was evaluated and compared with those of control specimens via in vitro fibroblast attachment studies; and (3) the attachment of a common oral microbe to the implant surface and its subsequent removal by exposure to the air-powder abrasive were also evaluated. Results indicate that exposure of implant specimens to the air-powder abrasive for various periods resulted in only slight changes in surface topography, i.e., rounding of angles and edges of the plasma-spray coating and occasional surface pitting. Examination by SEM and a statistical comparison of the difference between the mean numbers of attached fibroblasts between control and test groups revealed no statistical significance. In both specimen groups, fibroblasts exhibited uniform attachment over the entire implant surface. A comparison of test and control groups demonstrated 100% removal of bacteria from the surfaces of test specimens exposed to the air-powder abrasive and approximately a 75% removal from control specimens exposed to sterile water.