To immediately load, expose, or submerge in partial edentulism: a study of primary stability and treatment outcome.

PURPOSE: This study was undertaken to assess the predictive usefulness of preoperative bone density, as measured by computed tomography (CT), and the intraoperative implant stability measures of insertion torque (IT), Periotest values (PTV), and resonance frequency analysis (ie, implant stability quotient [ISQ]) toward developing an algorithm for successful immediate loading, one-step exposure, or submergence of dental implants. MATERIALS AND METHODS: Consecutively presenting patients requesting immediate loading in areas other than the anterior mandible were analyzed retrospectively. The implants were either immediately loaded, left exposed, or submerged on the basis of preoperative CT bone density and intraoperative primary stability measures. All implants surviving the traditional healing period were verified for osseointegration. RESULTS: Eighteen patients were analyzed retrospectively, and they received 58 implants. Seven implants failed, for a survival rate of 88%. Primary stability measurements at insertion were correlated with one another and with preoperative CT bone density. Preoperative mean bone density for surviving implants was greatest for immediately loaded implants (983 ± 83), lower for exposed implants (803 ± 29), and lowest (480 ± 23) for submerged implants. Bone density was significantly different between submerged implants that failed and those that survived. Mean IT for successful implants was higher than for those that failed. Mean PTVs were lower (ie, better) for successful versus failed implants, although this difference was significant only for submerged implants. CONCLUSIONS: In this group of patients, objective measures of bone density by CT, IT, PTV, and ISQ correlated with each other and therefore may provide a useful algorithm for making clinical implant loading decisions. Of the technologies applied in this group of patients, PTV was the most reliable predictor at implant placement of failure to osseointegrate.

Peri-implant soft-tissue health surrounding cement- and screw-retained implant restorations: a multi-center, 3-year prospective study.

OBJECTIVE: The purpose of this prospective clinical study was to evaluate peri-implant soft-tissue conditions and esthetic fulfillment during a 3-year follow-up period following prosthetic rehabilitation. MATERIAL AND METHODS: As part of a prospective multi-center study, 152 ITI dental implants were placed in 80 patients in the maxillary anterior region. Fifty-nine crowns (38.82%) were cement retained, while 93 (61.18%) crowns were screw retained. At loading and 3, 6, 12 and 36 months post-loading, modified plaque index (MPI), sulcus bleeding index (SBI), keratinized mucosa (KM), gingival level (GL), and esthetic fulfillment were recorded. RESULTS: All patients completed the study and no complications were reported. While statistically not significant at all time points, cement-retained crowns seemed to present a worsening trend in MPI and SBI scores. Interestingly, screw-retained crowns seemed to present an opposite picture, their MPI and SBI scores improved over time. While plaque accumulation, prophylaxis and depth of crown margin significantly affected levels of sulcus bleeding, prophylaxis alone played a key role in reducing plaque accumulation. No soft tissue recession was observed in either cement- or screw-retained crowns up to 3 years post-loading. Esthetic fulfillment survey revealed that patients did not have a preference for crown types; however, dentists favored cement-retained over screw-retained crowns. CONCLUSIONS: Peri-implant soft tissues responded more favorably to screw-retained crowns when compared with cement-retained crowns. However, no soft-tissue recession was observed in either type of crowns. Cement-retained crowns were preferred by dentists, while patients were equally satisfied with either type of crowns they received.