RESUMEN
BACKGROUND: To evaluate the effect of undersized drilling on the primary and secondary stability of immediate implants placed in the anterior maxilla. MATERIAL AND METHODS: A comparative randomized clinical trial was carried out in 30 healthy adults. Thirty tapered implants, 16 involving conventional drilling and 14 undersized drilling, were placed immediately after anterior maxillary tooth removal. Insertion torque and implant stability assessed by resonance frequency analysis (RFA) were evaluated at three different timepoints: at implant placement and 6 and 12 weeks post-implantation. The results were compared using parametric statistical tests. RESULTS: All implants showed adequate stability during follow-up. At implant placement, the undersized drilling group exhibited greater insertion torque values than the conventional drilling group, but stability assessed by RFA showed greater mean values in the conventional group. After 6 and 12 weeks of follow-up, both groups showed improved stability, though the RFA values remained comparatively higher in the conventional group. The differences were not statistically significant. CONCLUSIONS: Based on the results obtained, undersized drilling does not appear to afford significantly improved stability of immediate implants placed in the anterior zone of the maxilla during the osseointegration period.
Asunto(s)
Implantes Dentales , Maxilar , Adulto , Densidad Ósea , Implantación Dental Endoósea , Humanos , Maxilar/cirugía , Oseointegración , Análisis de Frecuencia de Resonancia , TorqueRESUMEN
PURPOSE: This study evaluated autogenous nerve grafts and expanded polytetrafluoroethylene (e-PTFE) and collagen tubes as conduits for the repair of continuity defects in the facial nerve of rabbits. MATERIALS AND METHODS: The buccal division of 24 facial nerves was isolated, transected, and separated 10 mm. The gap between the 2 nerve ends was then repaired with an autologous nerve graft or an e-PTFE or collagen conduit. Fifteen days and 1, 2, and 4 months after the procedure, the animals were subjected to electrophysiologic tests, killed, and the nerves were removed for histologic examination. RESULTS: At 15 days postsurgery, no regeneration was observed through the e-PTFE and collagen tubes or across the autologous nerve grafts at the midpoint of the specimens. However, regeneration across the chambers and autologous nerve grafts was seen in the following 4 months, although the number of axons regenerated was small. CONCLUSIONS: The results of the study indicate that e-PTFE and collagen tubing may be effective in the repair of continuity defects in peripheral nerves. However, further research will be necessary for generalization of this procedure.