In vitro preliminary evaluation of bacterial attachment on grooved and smooth healing abutments

This in vitro preliminary study investigated the attachment of Fusobacterium nucleatum and Porphyromonas gingivalis on titanium alloy healing abutments, which differed in their surface macro-morphology: one was groove-marked while the other was completely smooth. Altogether, twenty implant-healing abutments, ten of each macro-morphology, were evaluated with a single type of bacterial strain. Accordingly, four groups of five abutments each were created. The sterilized healing abutments with the cultured bacteria were placed under anaerobic conditions for 48 h at 37 °C. Afterwards, the abutments were examined with a scanning electron microscope, at a 2500x magnification. Attached bacteria were quantified in the four vertical quarters within the grooved abutments and in the two most coronal millimeters of the smooth abutments. The results were analyzed by applying two-way ANOVA, with square root transformation for a normal distribution. The bacterial attachment of both strains was statistically significantly larger in the grooved abutment areas than on the smooth surfaces (p ≤ 0.0001), twenty times so for Porphyromonas gingivalis and a hundred times so for Fusobacterium nucleatum.