Stability of 6-mm Implants Placed Crestally and Supracrestally by Surgeons of Varying Experience In Vitro

Purpose: To evaluate the importance of clinical expertise on implant stability (IS) of 6-mm implants placed in vitro. Materials and Methods: A total of 480 implants (Tapered Short Implants, BioHorizons) (6-mm length and diameters of 4.6 mm and 5.8 mm) were used in this study. All implants were placed by three clinicians with different surgical experience levels: one master clinician (G.E.R.), one third-year resident with experience with nearly 100 implants (A.Z.), and one resident without implant surgical experience (N.E.E.). Each clinician placed 40 implants of each diameter (4.6 mm and 5.8 mm) in type 1 bone (dense) and 40 implants of each diameter in type 4 bone (soft; Sawbones), resulting in a total of 160 implants per clinician. Additionally, within each bone type, half of the implants (20 per diameter) were placed at bone level (crestal level), while the other half were placed 1 mm above the bone crest (supracrestal). The IS was evaluated using an Osstell device. Comparison of IS between all three clinicians for all implant groups was performed using one-way analysis of variance (ANOVA) and Bonferroni correction for multiple comparisons regarding the significance level, which was set at P < .05. Results: Implants placed supracrestally showed differences between the experienced and inexperienced clinicians but not between the master clinician and third-year resident. A similar trend can be observed with implants placed at crestal levels. In type 1 bone, greater stability was achieved for the experienced clinicians when compared to the inexperienced one (P < .0001); however, in type 4 bone, the comparison of stability showed a P value < .0001 for all groups, with greater IS values for the master clinician over both residents. Conclusions: Overall, both the master and moderately experienced surgeons presented increased stability on 6-mm implants compared to the inexperienced resident.