RESUMEN
PURPOSE: To retrospectively investigate the one-year clinical outcome following a standardized treatment protocol for immediate loading. The protocol mandates predefined requirements for implant stability. If fulfilled, immediate loading of the implants is performed with a simplified prosthetic protocol which includes one-time impression at the time of surgery and definitive restoration within eight weeks. METHODS: Twenty-five patients were treated with 48 Neoss ProActive Tapered implants. Minimum primary stability was established before subjecting the implants to immediate nonfunctional load. Definitive prostheses were delivered six to eight weeks from implant placement. Insertion torque (IT), resonance frequency analysis (RFA), intraoral radiographs, and impressions of implant positions were registered at implant placement. During clinical follow-up, RFA was measured at two, four, and six to eight weeks and six months from implant placement to monitor continued implant stability. Marginal bone level measurements were performed at implant placement, six-month, and one-year follow-up visits. RESULTS: IT was over 40 N·cm for 46 implants. Two implants with IT <30 N·cm were both splinted to another implant with IT >50 N·cm, tightening the retention screw with low forces. No implants were lost during the observation period. Mean RFA measurements remained stable without any decrease during the initial six-month healing phase. Mean marginal bone remodeling was -0.47 ± 0.38 mm from implant placement to 1 year. No significant difference was found for marginal bone remodeling between implants placed in the healed bone or fresh extraction sockets. CONCLUSION: Within the limits of this study, it is concluded that using a simplified immediate loading protocol can be predictably applied to reduce the overall treatment time and the number of clinical sessions.
RESUMEN
PURPOSE: To study the clinical/radiographic outcomes and stability of a tapered implant design with a hydrophilic surface when placed in the maxilla using various protocols and followed for one year. METHODS: Ninety-seven consecutive patients treated as part of daily routine in two clinics with 163 tapered implants in healed sites, in extraction sockets and together with bone augmentation procedures in the maxilla were evaluated after one year in function. Individual healing periods varying from 0 to 6 months had been used. Insertion torque (IT) and resonance frequency analysis (RFA) measurements were made at baseline. Follow-up RFA registrations were made after 6 and 12 months of loading. The marginal bone levels were measured in intraoral radiographs from baseline and after 12 months. A reference group consisting of 163 consecutive straight maxillary implants was used for the comparison of baseline IT and RFA measurements. RESULTS: Five implants failed before loading, giving an implant survival rate of 96.9% and a prosthesis survival rate of 99.4% after one year. The mean marginal bone loss after one year was 0.5 mm (SD 0.4). The mean IT was statistically significantly higher for tapered than for straight reference implants (41.3 ± 12.0 Ncm vs 33.6 ± 12.5 Ncm, p < 0.001). The tapered implants showed a statistically insignificantly higher mean ISQ value than the straight references implants (73.7 ± 6.4 ISQ vs 72.2 ± 8.0 ISQ, p=0.119). There was no correlation between IT and marginal bone loss. There was a correlation between IT and RFA measurements (p < 0.001). CONCLUSION: The tapered implant showed a high survival rate and minimal marginal bone loss after one year in function when using various protocols for placement. The tapered implant showed significantly higher insertion torque values than straight reference implants.