Removal torque values of titanium implants in the maxilla of miniature pigs.

The purpose of this study was to compare side-by-side two different titanium screw-type implants in the maxillae of miniature pigs. The test implants had a machined and acid-etched surface (Osseotite) whereas the control implants were sandblasted and acid-etched (SLA). After 4, 8, and 12 weeks of healing, removal torque testing was performed to evaluate the shear strength of the bone-implant interface for both implant types. The results demonstrated significant differences between both implant types (P < .01). Osseotite implants revealed mean removal torque values (RTV) of 62.5 Ncm at 4 weeks, 87.6 Ncm at 8 weeks, and 95.7 Ncm at 12 weeks of healing. In contrast, the SLA implants demonstrated mean RTV of 109.6 Ncm, 196.7 Ncm, and 186.8 Ncm at corresponding healing periods. The mean RTV for SLA implants was 75% to 125% higher than for Osseotite implants up to 3 months of healing.

Localized ridge augmentation using guided bone regeneration. 1. Surgical procedure in the maxilla.

A new surgical technique for localized ridge augmentation prior to the placement of dental implants has been developed. The technique is based on the principle of guided bone regeneration utilizing barrier membranes. In the present article, the currently used surgical procedure is presented through two case reports. In addition, the different aspects of the surgical technique needed to achieve a predictable success are discussed.

Localized ridge augmentation using guided bone regeneration. II. Surgical procedure in the mandible.

The principle of guided bone regeneration can be applied for localized ridge augmentation in a staged approach. The surgical procedure for the mandible is presented through three case reports. Incision technique and flap design, utilization of autogenous bone grafts as a membrane-supporting device and osteoconductive scaffold, proper placement of barrier membranes and their stabilization with miniscrews, and wound closure are all emphasized. Furthermore, factors essential for achieving predictable results with barrier membranes for localized ridge augmentation and the benefits of combining barrier membranes with autogenous bone grafts are discussed.

Lateral ridge augmentation using autografts and barrier membranes: a clinical study with 40 partially edentulous patients.

PURPOSE: This study evaluated predictability and treatment outcome of the combined application of autografts and expanded-polytetrafluoroethylene (e-PTFE) membranes for lateral ridge augmentation in partially edentulous patients using a staged approach. MATERIALS AND METHODS: Forty partially edentulous patients were consecutively treated. Emphasis was given to a lateral incision technique, perforation of the cortex to open the marrow cavity, stable placement of corticocancellous autografts and bone chips, precise adaptation of the e-PTFE membranes and stabilization with miniscrews, and a tension-free primary soft tissue closure. After 7 to 13 months, the sites were reopened for membrane removal and implant placement. RESULTS: All but one patient showed complication-free soft tissue healing. After reopening, 38 patients exhibited excellent ridge augmentation, whereas two had compromised results, with soft tissue encapsulation of some bone chips. None of the applied block grafts showed clinical signs of resorption. Preaugmentation and postaugmentation measurements showed an enlargement of the crest width from a mean of 3.5 mm to 7.1 mm. This allowed the placement of nonsubmerged titanium implants in all 40 patients. CONCLUSIONS: The current study demonstrates that the combined application of autografts and e-PTFE membranes is a predictable surgical procedure for lateral ridge augmentation that results in an enlargement of the alveolar crest in partially edentulous patients. The autografts support the membrane and activate bone formation with their osteoconductive and osteoinductive properties. The membrane acts as a physical barrier to nonosteogenic soft tissue cells, and protects the autografts against resorption during healing.

Long-term evaluation of non-submerged ITI implants. Part 1: 8-year life table analysis of a prospective multi-center study with 2359 implants.

In the present multi-center study, non-submerged ITI implants were prospectively followed to evaluate their long-term prognosis in fully and partially edentulous patients. In a total of 1003 patients, 2359 implants were consecutively inserted. Following a healing period of 3-6 months, the successfully integrated implants were restored with 393 removable and 758 fixed restorations. Subsequently, all consecutive implants were documented annually up to 8 years. At each examination, the clinical status of all implants was evaluated according to predefined criteria of success. Therefore, the data base allowed the evaluation of 8-year cumulative survival and success rates for 2359 implants. In addition, cumulative success rates were calculated for implant subgroups divided per implant type, implant length, and implant location. Furthermore, the actual 5-year survival and success rates could be determined for 488 implants. During the healing period, 13 implants did not successfully integrate, whereas 2346 implants fulfilled the predefined criteria of success. This corresponds with an early failure rate of 0.55%. During follow-up, 19 implants were classified as failures due to several reasons. In addition, 17 implants (approximately 0.8%) demonstrated at the last annual examination a suppurative periimplant infection. Including 127 drop out implants (= 5.4% drop out rate) into the calculation, the 8-year cumulative survival and success rates resulted in 96.7% and 93.3%, respectively. The analysis of implant subgroups showed slightly more favorable cumulative success rates for screw type implants (> 95%) compared to hollow-cylinder implants (91.3%), and clearly better success rates for mandibular implants (approximately 95%) when compared to maxillary implants (approximately 87%). The actual 5-year survival and success rates of 488 implants with 98.2% and 97.3%, respectively, were slightly better than the estimated 5-year cumulative survival and success rates of 2359 implants indicating that the applied life table analysis is a reliable statistical method to evaluate the long-term prognosis of dental implants. It can be concluded that non-submerged ITI implants maintain success rates well above 90% in different clinical centers for observation periods up to 8 years.

Interface shear strength of titanium implants with a sandblasted and acid-etched surface: a biomechanical study in the maxilla of miniature pigs.

The purpose of the present study was to evaluate the interface shear strength of unloaded titanium implants with a sandblasted and acid-etched (SLA) surface in the maxilla of miniature pigs. The two best documented surfaces in implant dentistry, the machined and the titanium plasma-sprayed (TPS) surfaces served as controls. After 4, 8, and 12 weeks of healing, removal torque testing was performed to evaluate the interface shear strength of each implant type. The results revealed statistically significant differences between the machined and the two rough titanium surfaces (p <.00001). The machined surface demonstrated mean removal torque values (RTV) between 0.13 and 0.26 Nm, whereas the RTV of the two rough surfaces ranged between 1.14 and 1.56 Nm. At 4 weeks of healing, the SLA implants yielded a higher mean RTV than the TPS implants (1.39 vs. 1. 14 Nm) without reaching statistical significance. At 8 and 12 weeks of healing, the two rough surfaces showed similar mean RTVs. The implant position also had a significant influence on removal torques for each implant type primarily owing to differences in density in the periimplant bone structure. It can be concluded that the interface shear strength of titanium implants is significantly influenced by their surface characteristics, since the machined titanium surface demonstrated significantly lower RTV in the maxilla of miniature pigs compared with the TPS and SLA surfaces.