ABSTRACT
The primary stability of implants should be high on insertion into fresh extraction sockets. Torque-fitting and resonance frequency analyses (RFA) are used to assess primary implant anchorage and stability. The torque-fitting and RFA of implants placed in conventional surgical sockets and sockets with controlled coronal bone defects was compared. The possible relation between torque-fitting and RFA was explored. Ø 3.3 mm x 12 mm implants were placed in 16 sockets finalized with Ø 2.8mm surgical pilot drills in the right iliac crests of two fresh cadavers (control). In the test group, implants were placed into sockets prepared by Ø 2.8mm drill followed by Ø 4.2mm twist drills to a depth of 6mm to create circumferential controlled coronal bone defects (50% bone loss). Primary implant stability was assessed using insertion torque values (ITV) followed by RFA. Mean ITV and RFA measurements for test groups (7.83+/-0.91 N cm and 40.88+/-3.57) were significantly lower than controls (14.80+/-1 N cm and 66.31+/-0.9) (P<0.05). Reductions of ITV and RFA measurements in relation to bone defect were 47% and 38%. The existence of controlled bone defects eliminating contact coronally leads to decrease in torque-fitting and primary stability of implants. No relationship was observed between torque-fitting and RFA.
