Differences in implant stability associated with various methods of preparation of the implant bed: An in vitro study

Statement of problem It is difficult to achieve the primary stability necessary for immediate loading in the posterior maxilla because of thin cortical bone, low density trabecular bone, and inadequate bone height due to the presence of the maxillary sinus. Purpose The purpose of this study was to examine the primary stability of dental implants placed by using different methods of preparation for in vitro monocortical and bicortical models of the posterior maxilla. Material and methods Sixty screw-shaped implants (4.0 × 10 mm) were inserted into solid rigid polyurethane blocks. The implants were divided into 6 groups (n=10) to test 2 variables: 1) location (monocortical or bicortical block) and 2) preparation method (standard preparation, underpreparation, or the osteotome technique). The insertion and removal torques were measured and resonance frequency analysis (RFA) was performed to determine the primary stability of each implant. Insertion and removal torque data were analyzed by 2-way ANOVA, followed by the post hoc Tukey HSD multiple comparison test. RFA data were analyzed by 2-way and 1-way ANOVAs and the Tukey HSD multiple comparison test (α=.05). The Pearson correlation analysis was also performed to examine correlations among the values. Results The preparation method had a significant effect on insertion torque, RFA value, and removal torque; however location had a significant effect only on the removal torque ( P