Analysis in vitro of the insertion torque of hybrid tapered implants with different types of instrumentation and two clinical cases report

Aim The aim of this study was to observe the behavior of the hybrid implants, evaluating the insertion test with different drilling protocols and present two case reports of hybrid implant placed in the upper arch. Materials and methods For the in vitro study 50 implants were placed in 2 different types of synthetic bone blocks composed of rigid solid polyurethane (high density, type I, and low density, type IV). The implants were divided into five groups (n=10): Group 1 (Test) hybrid/conical implants of 3.75 mm x 13 mm placed in a high density bone block with oversized instrumentation; Group 2 (Control) cutting/cylindrical of 3.75 mm x 13 mm, placed in a high density bone block with regular instrumentation; Group 3 (Test) hybrid/conical implants of 4.3 mm x 13 mm placed in a low density bone block with undersized instrumentation; Group 4 (Test) hybrid/conical implants of 4.3 mm x 13 mm placed in a low density bone block with regular instrumentation; Group 5 (Control) compact/conical implants of 4.3 mm x 13 mm  placed in a low density bone block with regular instrumentation. Two cases are reported of hybrid implants placed in the maxilla with 12-month follow up. Results No significant difference was observed between hybrid/conical implants and the control group, according to final placement torque in high and low density bone. However, undersized instrumentation showed a significantly increased final torque placement for hybrid/conical implant. Conclusions Implant macrostructure, bone instrumentation technique influence the insertion torque for hybrid/conical implants. At the 12-month follow-up the implants were stable.