A One-year Follow-up Study of a Tapered Hydrophilic Implant Design Using Various Placement Protocols in the Maxilla

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

The radiological evaluation of posterior superior alveolar artery topography by using computed tomography

Background Posterior superior alveolar artery (PSAA) is the most important limiting anatomic structure while lateral approach sinus surgeries. PSAA should be taken into consideration to avoid bleeding during preparation of bony window. Purpose The aim of this article was to inform topography of PSAA and to evaluate measurements of this vital structure. Materials and Methods Three hundred and fifty-four cone-beam computed tomography (CBCT) images of PSAA from 177 patients were evaluated retrospectively. Localization of PSAA, diameter of PSAA, classification of PSAA diameter, distance between PSAA and crest, buccal bone thickness, palatal bone thickness, crest height, and crest width were recorded for each posterior tooth separately. Results The mean age of 177 patients was 54.05 +/- 18.33 years. Although the most frequent localization of PSAA was intraosseous in premolar region, they were below Schneiderian membrane in molars. PSAA diameter was measured frequently less than 1 mm for all posterior teeth. Although palatal bone thickness was higher in premolar region than molars, no statistical relationship was found between tooth region and buccal bone thickness (P > 0.05). The width of residual ridge was measured both wider apically and posteriorly. Positive correlation was observed between buccal bone thickness and PSAA diameter in first molar and premolar regions (P < 0.05). Conclusions Detailed evaluation of patients by CBCT provided us the opportunity to draw topography of PSAA and inform about overall measurements of PSAA in all posterior teeth region