Supra- and subgingival biofilm formation on implant abutments with different surface characteristics.

PURPOSE: The aim of the present study was to establish a noninvasive method for quantitative analysis of supra- and subgingival biofilm formation on dental implants considering different surface modifications. MATERIALS AND METHODS: Patients of both sexes were included. They had to be in generally good health, partially edentulous, and the recipient of at least 1 screw-type implant with an abutment possessing supra- and subgingival areas. Healing abutments were inserted for 14 days. The abutment surfaces were divided into quadrants that were sandblasted, ground, acid-etched, and untreated (with the latter surface as a control). Biofilm formation on the healing abutments was analyzed using scanning electron microscopy, including secondary-electron and Rutherford backscattering-detection methods. Calculation of biofilm-covered surfaces was performed depending on grey-values, considering supra- and subgingival areas. After calculating absolute and relative biofilm-covered surfaces depending on localization, the influence of surface modification on biofilm formation was analyzed. RESULTS: Fifteen healing abutments were inserted in 11 patients. In all surface properties plaque adhesion in supragingival areas was significantly higher (17.3% +/- 23.1%) than in subgingival areas (0.8% +/- 1.0%). Biofilm accumulation in supragingival areas was significantly increasing by higher surface roughness, whereas this influence was not detected in subgingival areas. CONCLUSION: The described method is valuable for investigation of supra- and subgingival biofilm adhesion on surface-modified implant abutments. There was a significant influence of surface localization (supra- and subgingival) as well as surface modification on biofilm formation.

Comparative analysis of biofilm formation on dental implant abutments with respect to supra- and subgingival areas: polytetrafluoroethylene versus titanium.

The aim of the present in vivo study was to examine the effect of polytetrafluoroethylene (PTFE) surfaces on biofilm formation on dental implant abutments in comparison to titanium surfaces. Fifteen modified abutments with incorporated PTFE plates were inserted in 10 patients for 14 days. Scanning electron microscopy techniques were used to examine biofilm formation on different surfaces and to determine the percentage of surface coverage. Significantly less biofilm was detected on PTFE surfaces than on titanium surfaces. The results of this study reveal that PTFE surfaces reduce biofilm formation to a minimum on dental implant abutments. Int J Prosthodont 2011;24:373-375.

Comparative analysis of long-term biofilm formation on metal and ceramic brackets.

OBJECTIVE: To test the null hypothesis that stainless steel and ceramic brackets show no differences in biofilm adhesion. MATERIALS AND METHODS: Twenty adolescents (6 boys, 14 girls) who had received fixed orthodontic therapy for 18.9 ± 3.2 months were divided into a metal and a ceramic bracket group. Thirty brackets per group were taken from central incisors, canines, and second premolars and quantitatively analyzed for biofilm coverage with the Rutherford backscattering detection method. Five micrographs were obtained per bracket with views from the buccal, mesial, distal, gingival, and occlusal aspects, resulting in a total of 300 images. Biofilm formation between groups was compared using the Mann-Whitney U-test (α = .05). RESULTS: Total biofilm formation was 12.5% ± 5.7% (3.3 ± 1.6 mm(2)) of the surface on metal and 5.6% ± 2.4% (1.5 ± 0.6 mm(2)) on ceramic brackets. Differences between groups were statistically significant (P < .05). A pairwise comparison of biofilm formation revealed significantly lower biofilm formation on ceramic brackets with respect to intraoral location (central incisor, canine, second premolar) and bracket surface (buccal, mesial, distal). CONCLUSIONS: The hypothesis was rejected. The results indicate that ceramic brackets exhibit less long-term biofilm accumulation than metal brackets.