Counterclockwise Drilling with Conventional Tapered Drills Produces Soft Bone Densification

Objectives: To evaluate the resultant density of the implant bed cortical and implant bed wall when these are prepared with clockwise Vs. counterclockwise drilling with different tapered drills compared to osseodensification drills
Methods: One hundred and twenty implant beds with a diameter of 4.0mm and 10mm depth were prepared in synthetic bone blocks resembling Type III bone density. Sixty beds were prepared with clockwise drilling and sixty with counterclockwise drilling with irrigation and alternating pumping movement. Three subgroups of twenty each (clockwise and counterclockwise) were prepared with three different drill designs. Design 1 (Osseodensification Versah drills), Design 2 (Tapered drill, Biohorizons), Design 2 (Tapered drill, Straumann). The cortical and the bed wall density were evaluated with optical coherence tomography and digital density radiographic analysis respectively. Nonparametric Tukey test was used for the evaluation of the differences in bone density between groups. Significance was set at p<0.05
Results: Drilling with clockwise direction did not show differences between groups at the density of the cortical area or at the density of the implant bed walls p>0.05. However, when drilling with the counterclockwise direction the density at the cortical and implant bed walls increased in all the groups p<0.05. Subgroup analysis showed that higher density was present at the cortical area and apex compared to the middle section of the walls in all the groups.
Conclusions: Counterclockwise drilling with tapered drills can increase the cortical and apical bone density in Type III bone comparable to the osseodensification technique.