A 4- to 5-year retrospective clinical and radiographic study of Neoss implants placed with or without GBR procedures.

BACKGROUND: New dental implant systems are continuously introduced to the market. It is important that clinicians report their experiences with these implants when used in different situations. AIM: The study aims to report the outcomes from a retrospective study on Neoss implants when used with or without guided bone regeneration (GBR) procedures. MATERIALS AND METHODS: The study group comprised of 50 consecutive patients previously treated with 183 Neoss implants (Neoss Ltd., Harrogate, UK) in 53 sites because of single, partial, or total tooth loss. Implants were placed in healed bone in 23 sites, while a GBR procedure was used in 30 sites in conjunction with implant placement. A healing period of 3 to 6 months was utilized in 45 sites and in 8 sites a crown/bridge was fitted within a few days for immediate/early function. The number of failures, withdrawn and dropout implants was analyzed in a life-table. All available intraoral radiographs from baseline and annual check-ups were analyzed with regard to marginal bone level and bone loss. RESULTS: A cumulative survival rate (CSR) of 98.2% was found for the non-GBR group and 93.5% for the GBR group with an overall CSR of 95.0% after up to 5 years of loading. In spite of the failures, all patients received and maintained their prostheses. Based on all available radiographs, the bone level was situated 1.3±0.8mm (n=159) below the top of the collar at baseline and 1.7±0.8mm (n=60) after 5 years of follow-up. Based on paired baseline and 1-year (n=70) and 5-year radiographs (n=59), the bone loss was found to be 0.4±0.9 and 0.4±0.9mm, respectively. There were no statistically significant differences between GBR and non-GBR sites with regard to implant survival or bone loss. CONCLUSIONS: The Neoss implant system showed good clinical and radiographic results after up to 5 years in function.

A prospective multicenter study using two different surgical approaches in the mandible with turned Brånemark implants: conventional loading using fixed prostheses.

BACKGROUND: The use of a submerged implant system in a nonsubmerged surgical procedure has been reported to have promising results. At the time this study was initiated, no prospective, comparative studies with randomization between submerged and nonsubmerged surgical techniques had been published. PURPOSE: To evaluate the submerged and nonsubmerged surgical techniques when treating mandibular edentulism using a submerged implant system, with regard to implant survival and complications. MATERIALS AND METHODS: A total of 77 patients were included and treated at nine clinics in Sweden and Norway. In total, 404 Brånemark System implants (standard and MkII implants) were inserted in the edentulous mandible; 198 implants according to the nonsubmerged protocol and 206 implants according to the traditional submerged procedure. The follow-up period was up to 36 months after prosthesis insertion. RESULTS: In the nonsubmerged group, 17 implants out of 198 implants (8.6%) were lost and in the submerged group, 5 out of 206 implants (2.4%) were lost. All implant failures occurred before the delivery of the final prosthesis. No major complications were reported during the implant surgery. However, at the clinical check-up postoperatively and at the abutment connection surgery, 6 patients in the nonsubmerged group complained of pain at the implant sites, whereas there were no complaints of pain in the submerged group. CONCLUSIONS: The results of this study suggest that a turned Brånemark implant designed for a submerged implant placement procedure can be used in a nonsubmerged procedure and may be as predictable as the conventional submerged approach.

One-year results of a prospective multicenter study on Brånemark System implants with a TiUnite surface.

BACKGROUND: A moderately rough surface implant (TiUnite, Nobel Biocare AB, Göteborg, Sweden) was introduced in 2000. Laboratory studies and some clinical studies have demonstrated excellent bone response in the early healing phase. PURPOSE: The aim of this prospective multicenter study was to follow a large number of consecutively treated patients using Brånemark System implants with the TiUnite surface. The current report constitutes the 1-year data of a planned 3-year study. MATERIALS AND METHODS: Originally, the study comprised 43 surgeons from 22 centers in Sweden, Norway, and Finland. Five centers were excluded from the study because of poor compliance. Thus, 187 patients treated with 478 TiUnite implants were followed during 1 year of function. The majority of implants were inserted in maxillae (357 implants), and 78 of the implant sites were assigned the quality 4 figure. Radiographic evaluations were performed. RESULTS: Five implants were lost up to and including the 1-year follow-up, revealing implant cumulative survival rates of 98.6% and 100% for maxillae and mandibles, respectively. Three implants failed in quality 4 bone (3.8%). The mean marginal bone resorption at the end of the study period was 1.4 mm. The number of withdrawals of patients during the first year was high (19.3%). CONCLUSION: The present investigation showed a high implant cumulative survival rate of 98.9%. Values of marginal bone resorption were within normal ranges. No adverse effects of the TiUnite surface were reported, and complications during the study period were few and similar to those reported for the turned implant surface. However, the high number of excluded patients and the relatively high number of withdrawals must be observed and considered when interpreting data.

A retrospective clinical study of wide-diameter implants used in posterior edentulous areas.

PURPOSE: The purpose of this study was to examine retrospectively the outcome of wide-diameter dental implants used to retain fixed restorations in the posterior segments of the maxilla and mandible. MATERIALS AND METHODS: Fifty-two patients were consecutively treated between 1997 and 2000 with 78 Wide-Platform (WP) Mk II implants in the posterior regions of the maxilla and/or mandible. All treated patients were called for a retrospective examination between September and November 2001. At the examination, data regarding general health and clinical and radiographic parameters were collected according to a strict protocol. Thirty-four women and 18 men with a mean age of 55 years (range 19 to 81 years) participated. Twenty-three WP implants were placed in the maxilla and 55 in the mandible. The mean time in situ was 33 months (range of 11 to 58 months). RESULTS: Of 78 implants, 8 had been lost by the time of reexamination. Five women lost 1 implant each in the maxilla, and 2 men lost 3 implants in the mandible. The survival rate was 89.8%. DISCUSSION: The results are encouraging because the WP implants were placed in rather unfavorable situations (generally poor bone quality, compromised bone volume, and larger occlusal forces). CONCLUSION: Based on the reported survival rate, wide-diameter implants present an acceptable treatment alternative.

Tapered implants in jaws with soft bone quality: a clinical and radiographic 1-year study of the Brånemark System Mark IV fixture.

BACKGROUND: The survival rate of oral implants in soft-quality bone has been demonstrated to be inferior to that of implants inserted in good-quality bone. A possible way to increase the survival rate in soft-quality bone may be to use a tapered implant. Such an implant has been developed and manufactured by Nobel Biocare AB, Gothenburg, Sweden. So far, there have been only a few publications regarding this implant. PURPOSE: The aim of the study was to compare the outcome of using the tapered Brånemark System Mark IV fixture with the outcome of using earlier Brånemark fixtures in a controlled prospective study. MATERIALS AND METHODS: The study was performed as a multicenter study including seven specialist centers. The material consisted of 40 patients in need of implant-supported bridges in the maxilla. Twenty-five patients belonged to the test group, in which the tapered Mark IV implants were inserted, and 15 patients belonged to the control group, in which Brånemark Standard or Mark II implants were used. The patients were allocated to the test group or the control group according to randomization schedules. The implants were inserted according to the guidelines for Brånemark implants. A two-stage surgical protocol was used, and abutment connection was made 6 months after fixture insertion. The test group comprised 97 Mark IV implants, and the control group made up 92 implants. The prosthetic procedure followed the guidelines for Brånemark implants, and all patients were provided with full fixed maxillary bridges. The patients were followed up with clinical and radiographic records for 1 year after loading. RESULTS: The survival rate was 96.9% for the Mark IV implants and 98.9% for the control implants. There was no significant difference between the two groups. There was a mean marginal bone loss of 0.2 mm during the observation period, and there was no difference between test implants and control implants. CONCLUSIONS: With regard to survival rate and marginal bone level changes, no differences could be demonstrated between the Mark IV tapered implant and the Brånemark implants used earlier. However, compared with earlier results of Brånemark implants in soft-quality bone, the Mark IV implant demonstrated an improved survival rate.