Factors influencing marginal bone loss at a hydrophilic implant design placed with or without GBR procedures: A 5-year retrospective study.

BACKGROUND: Ongoing marginal bone loss is a threat to the longevity of implant-supported prostheses. AIM: The aim of the present study was to retrospectively evaluate the survival rate and factors affecting marginal bone levels at a hydrophilic implant design after 5 years in function. MATERIALS AND METHODS: The study group consisted of 51 consecutive patients previously treated with 159 hydrophilic implants (Neoss Straight Proactive implants) and scheduled for annual check-ups with clinical and radiographic examinations during 5 years. Data were compiled for the entire study population as well as for two subgroups: one where guided bone regeneration (GBR) was performed (91 implants) and the other where no GBR procedures (68 implants) were performed. Marginal bone levels were measured from peri-apical radiographs taken at placement and annual follow-ups. Statistical analyses were applied to evaluate the effect of different factors on marginal bone remodeling. RESULTS: Two implant failures, one from each subgroup, occurred during the first year of function resulting in an overall cumulative survival rate (CSR) of 98.7% after 5 years of loading. The mean marginal bone loss amounted to 0.7 ± 0.7 mm after 1 year and 0.8 ± 0.6 mm after 5 years. No implants showed more than 3 mm bone loss after 5 years. Age, gender, implant position, biotype, implant diameter, implant length, indication, surgical/loading protocol, and ISQ at prosthesis delivery were found to affect bone remodeling. No significant differences or correlations were seen for smoking, jaw, bone quantity, bone quality, GBR, sinus lift, and ISQ at implant placement. CONCLUSIONS: The present implant design performed well with few failures and minimal marginal bone loss after 5 years of loading. Marginal bone remodeling at implants is a complex phenomenon, which is affected by many patient-, procedure-, and implant-related factors that need to be further investigated.

Results after wisdom tooth transplantation. A retrospective study.

Wisdom tooth transplants offer youth the possibility of biologically fixed tooth replacement in cases of premolar agenesis or premature loss of a molar. In the present study, 57 transplants of third molars were reviewed and evaluated retrospectively on preoperative findings (root growth stages, extraction sites, indication for transplantation), on postoperative clinical findings (local gingivitis, periodontal probing values, tooth mobility, percussion sound and percussion pain) and on radiological findings (tertiary build-up of dentin, osseous periradicular conditions, progress of root growth). Only the transplants which healed with a vital pulp and in a periodontally healthy state were considered successful. Upper and lower wisdom teeth having 50% to 75% root growth progression were transplanted. The postoperative follow-up observation period averaged 26.4 months. The success of a wisdom tooth transplantation was not influenced by the root growth stage (p = 1), the extraction location of wisdom teeth (p = 0.45), or the feasibility for a transplantation (p = 0.56). Three teeth showed pulpal necrosis with apical periodontitis and were counted as failures. The success rate was rather high with 54 out of 57 transplants (94.7%), therefore wisdom tooth transplantations, with careful selection of a suitable graft and its gentle removal, can be described as a good predictable treatment.

Clinical outcome in periradicular surgery: effect of patient- and tooth-related factors--a multicenter study.

OBJECTIVE: To evaluate the effect of patient- and tooth-related factors on the outcome of apical surgery in a multicenter study. METHOD AND MATERIALS: A total of 281 teeth in 255 patients undergoing periradicular surgery were investigated clinically and radiographically 6 to 12 months postoperatively. RESULTS: The overall success rate was 88.0%. Sex was a significant (P = .024) predictor, with a success rate of 89.8% in females and 84.0% in males. The success rate was significantly higher in patients 31 to 40 years of age. The treatment of premolars resulted in a significantly higher success rate (91.9%) than the treatment of anterior teeth (86.1%, P = .042) and molars (86.4 %, P = .026). The loss of the buccal bone plate and the extension of apical osteolysis to the furcation area in molars resulted in a considerably lower success rate. Lesion size, preoperative pain, tenderness to percussion, fistula, and resurgery were significant factors. CONCLUSION: There are several factors influencing the success rate of apical surgery that must be taken into account when considering apical surgery as a treatment alternative.