Essential oils and zirconia dental implant materials.

PURPOSE: This study was conducted to evaluate the effectiveness of natural antimicrobial agents in reducing biofilm development on different titanium and zirconia dental implant materials in vitro using a constant depth film fermentor (CDFF). MATERIALS AND METHODS: Contact angles and surface free energy were determined for all surfaces. Biofilms were grown on disks of polished partially stabilized zirconia, titanium blasted with zirconia, titanium blasted with zirconia and acid-etched, and polished titanium using a CDFF to simulate oral cavity conditions. Antimicrobials (cinnamon oil, clove oil, chlorhexidine gluconate, or 0.5% Tween 80) were pulsed twice daily to the biofilm to mimic application in the oral cavity. Samples were taken after 6, 24, and 48 hours. Serial dilutions were made and plated onto agar. Bacterial colonies were counted to determine colony-forming units/mL. RESULTS: Treatment of different implant material surfaces with the various antimicrobial agents led to significant increases in wettability and free energy on all surfaces. All surfaces showed a remarkable decrease in bacterial adhesion in the first 2 days in a relatively similar manner, with significant reduction in most of them, particularly after 48 hours. CONCLUSIONS: Functionalization of different dental implant material surfaces with essential oils resulted in immediate and ongoing antibacterial and antiplaque activities, and this antibacterial effect was enhanced with increased plaque age. Differences in the type of material seemed to have little effect on bacterial adhesion after treatment with antimicrobial agents. Expansion of this work with in vivo studies and clinical trials would be valuable.

Surface properties of titanium and zirconia dental implant materials and their effect on bacterial adhesion.

OBJECTIVES: Zirconia ceramic material has been widely used in implant dentistry. In this in vitro study the physiochemical properties of titanium and zirconia materials were investigated and the affinity of different bacteria to different materials was compared. METHODS: Disc samples with different surface states were used: polished partially stabilized zirconia (PZ), titanium blasted with zirconia (TBZ), titanium blasted with zirconia then acid etched (TBZA), and polished titanium (PT) as a control. Surface topography was examined using scanning electron microscopy and profilometry. Contact angle, surface free energy (SFE), surface microhardness and chemical composition were determined. Disc samples were separately incubated with Streptococcus mitis and Prevotella nigrescens, either with or without pre-coating with human saliva, for 6h and the surface area covered by bacteria was calculated from fluorescence microscope images. RESULTS: PZ and TBZ exhibited lower surface free energy and lesser surface wettability than PT. Also, PZ and TBZ surfaces showed lower percentage of bacterial adhesion compared with control PT surface. CONCLUSIONS: The zirconia material and titanium blasted with zirconia surface (TBZ surface) showed superior effect to titanium material in reducing the adhesion of the experimented bacteria especially after coating with saliva pellicle. Modifying titanium with zirconia lead to have the same surface properties of pure zirconia material in reducing bacterial adhesion. SFE appears to be the most important factors that determine initial bacterial adhesion to smooth surface.