Reintegration success of osseotite implants after intentional countertorque liberation in the endentulous human mandible.
OBJECTIVE
Implants that rotate during abutment screw tightening may not necessarily constitute implant failure. This prospective study was designed to determine to what degree integrated implants could gain a state of reintegration after intentional countertorque to liberation from the bone.


METHODS
There were 11 patients with fully edentulous mandibles restored with 2 "clinical" implants (3.75 x 10 mm) placed in the canine sites and an additional nonused "test" implant (3.75 x 10 mm) placed at the symphysis of the anterior mandible. At second-stage surgery, the test implant was countertorqued (T1) using a torque-metering wrench until it detached from the bone. The implant was returned to its original position and allowed to heal for a period until a second countertorque test (T2) was performed. In group A, patients (n = 5) received the countertorque T1 at 3 months and T2 at 5 months. In group B (n = 6) T1 was at 1.5 months, and T2 was at 3.5 months. After completion of T2, the group A test implants were removed with a 5-mm trephine for histologic examination.


RESULTS
For both groups, peak forces, all higher than 37.4 Ncm at T1, indicate that all implants were integrated. At T2, torque values were higher than T1 values for most of the test implants. The clinical implants were restored with "patrix" abutments and an overdenture. Histology staining showed distinction between old and new bone, which formed during the remodeling process.


CONCLUSIONS
The increase in peak forces needed to detach implants at T2 may be explained by bone-to-bone healing or the additional bone contact promoted by bleeding that occurred during the T1 procedure.


CONCLUSIONS
The results suggest that all implants were reintegrated after being intentionally countertorqued to liberation and resumed healing in the original osteotomy position.
Lucente
Jose
J
Galante
Jorge
J
Trisi
Paolo
P
Kenealy
James N
JN
D000368:Aged; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000601:surgery*; D008297:Male; D008334:Mandible / Q000601:surgery*; D008875:Middle Aged; D011446:Prospective Studies; D012399:Rotation; D019415:Torque
D015921:Dental Implants