Early plaque colonization on polished- and glazed-zirconium ceramic surface: Preliminary results

AIM: The purpose of this study was to evaluate the effect of ceramic surface polishing procedure on the early dental biofilm formation on zirconium ceramics. METHODS: Twenty samples (discs shape) of tetragonal zirconium polycrystal stabilized with yttrium ceramics (Y-TZP) for LAVA system were fabricated (5 mm diameter and 1.5 mm thickness). Two patients with high level of dental hygiene were selected for this study. Oral devices covering the crowns of the upper premolars and molars were fabricated for each participant. Glazed and polished samples of Y-TZP ceramics were fixed on the vestibular and palatal zones of the devices. After 20 min (8 samples) and 1 h (8 samples) in the oral environment, the samples were removed and analyzed in a scanning electron microscope. The surface topographies of 4 ceramic samples (2 glazed and 2 polished) were analyzed (control group: without exposition in oral environment). RESULTS: The glazed samples showed a more irregular surface than polished samples. Deposition of granular aggregates was verified on all the samples in the two times of the study analyzed. This granular material coated more intensely on irregular areas, and its thickness increased after 1 h. No difference was observed as to bacterial morphology in any time of the study. Cocci and rods-shaped prevailed. CONCLUSIONS: Glazed surfaces presented larger tendency to dental biofilm accumulation.