The design of the commercially available implant OsseoSpeed (R) (control) was changed to a tapered apex with a smaller apical diameter; OsseoSpeed(R) TX (test). The present study evaluated the clinical outcome of marginal bone level as primary outcome, and cumulative implant survivalrate, primary stability and condition of the peri-implant mucosa as secondary outcomes, one year after loading. 92 subjects (150 implants, ten centres), with partially or totally edentate maxillae were randomised to receive either test or control implants. One to six implants were placed in each subject using a one-stage surgical procedure. Subjects received a permanent prosthesis 10-12 weeks after implant placement and were followed for one year. 47 subjects in the test group received 82 implants and 45 subjects in the control group received 68 implants. Marginal bone level alterations from loading to 1-year follow-up was -0.02 +/- 0.41 mm (mean +/- SD) and -0.03 +/- 0.38 mm (mean +/- SD) for the test and the control group, respectively, indicating no difference between the groups. Non-inferiority was declared as confidence interval for the difference between control and test implants was no worse than 0.5 mm. The CSR was 98.8% in the test group and 100% in the control group, with no statistically significant difference between the groups. Change of the apical design of a commercially available implant showed no significant effect on marginal bone level and CSR compared to the control implant. Missing data and many investigators may have influenced on the result.

The aim of this study was to evaluate the long term outcome of furcation involved molars in a population treated for periodontal disease. Initially, the study sample was 147 referred periodontal patients. Periodontal treatment consisted of oral hygiene instructions, supra- and subgingival scaling and periodontal surgery. After treatment 99 patients participated in a two year study on root caries. The patients got maintenance treatment every third to fourth month during 2 years. At the end of that study the patients were periodontally healthy and were referred back for supportive treatment to the referring dentist. Thirteen to 16 years after periodontal treatment 81 patients were still alive and 64 accepted a re-examination. At the start of the observation period the remaining 64 patients had in total 1537 teeth. During the 13 to 16 year follow up 217 teeth were lost. The number of molars at baseline was 361. The number of furcation involvement with different degrees were; 267 (0), 67 (I), 25 (II) and 2 (III) respectively. Totally 69 molars were lost during follow up. The proportion of molar loss according to the degree of furcation involvements 0 to III at baseline were 15%, 29%, 40% and 100% respectively. It was a significant greater risk of loosing an initially furcation involved molar than a single rooted tooth (pandlt;0.0001). The risk of loosing an initially furcated molar increased with the degree of furcation involvement (degree I; pandlt;0.05, degree II; pandlt;0.01). I N CONCLUSION: During a long term observation period molars with furcation involvements are more frequently lost than not furcation involved molars. However, two thirds are still in function 13 to 16 years after treatment which indicate that molars with furcation involvements might survive long after periodontal treatment.