In vitro effect of anodization on surface roughness and bacterial adhesion to titanium abutments.

Statement of problem: Titanium abutments are considered the criterion standard for dental implants, yet the gray color poses esthetic concerns. Anodization has been proposed to enhance esthetics, but its effects on surface roughness and bacterial adhesion are unclear.

Purpose: The purpose of this in vitro study was to assess the effect of anodization on surface roughness and bacterial adhesion to titanium abutments.

Material and methods: Sixteen titanium abutments were divided into test (anodized) and control (nonanodized) groups (n=8). Anodization used 63 V from seven 9 V batteries and an electrolyte of 250 mL distilled water with 1 g trisodium phosphate. Surface roughness was measured with a profilometer at 4 mN force and 0.5 mm/second, assessing 3 supragingival points per specimen. In addition, 1 specimen from each group was selected for field-emission scanning electron microscopy (FE-SEM). Sterilized abutments were exposed to a Staphylococcus aureus suspension (10⁵ CFUs/mL) and then placed in phosphate-buffered saline (PBS), sonicated, vortexed, diluted, and cultured on agar. Bacterial adhesion was assessed after incubating 144 microplates at 37 °C for 24 hours. Colony counts were calculated using a dilution factor and serial dilution, and log 10 of CFUs/mL plotted. Data analysis used the Student t test for bacterial adhesion and the Mann-Whitney U test for surface roughness (α=.05).

Results: The test and control groups showed no significant difference in surface roughness (P>.05). However, bacterial adhesion to anodized abutments was significantly lower than that to control abutments (P<.001).

Conclusions: Anodization of titanium abutments significantly decreased bacterial adhesion and had no significant effect on surface roughness.