Immediate positioning of definitive abutments versus repeated abutment replacements in immediately loaded implants: effects on bone healing at the 1-year follow-up of a multicentre randomised controlled trial.

PURPOSE: To compare bone resorption around implants immediately loaded and restored using definitive abutments versus provisional abutments later replaced by custom-made abutments up to 12 months after implant placement. MATERIALS AND METHODS: 28 patients with partial edentulism were selected for a two-implant supported immediate restoration and randomised to provisional abutment (PA) and definitive abutment (DA) groups (14 patients for each group). In the PA group, implants were immediately restored using a platform-switched provisional titanium abutment. In the DA group, definitive platform-switched titanium abutments were tightened. In both groups, a provisional restoration was adapted, avoiding occlusal contacts. All implants were definitively restored after 3 months. In the PA group, patients underwent the standard prosthetic protocol: the abutments were removed and impressions were made directly on the implant platform. In the DA group, patients underwent the 'one abutment at one time' protocol: impressions were made of the abutments using a retraction cord. Peri-implant marginal bone levels were assessed immediately after surgery, and at 6- and 12-month follow-up examinations. RESULTS: At the 12-month follow-up no implant failed. In the PA group, peri-implant bone resorption was 0.359 mm after 6 months and 0.435 mm after 12 months. In the DA group, peri-implant bone resorption was 0.065 mm after 6 months and 0.094 mm after 12 months. There were statistically significant differences between the two groups for peri-implant bone level changes at the 6-month (P < 0.001) and the 12-month (P < 0.001) follow-up: 0.294 mm (CI 95% 0.276; 0.312) and 0.341 mm (CI 95% 0.322; 0.36), respectively. CONCLUSIONS: Within the limits of this study, it can be suggested that the non-removal of abutments placed at the time of surgery results in a statistically significant reduction of the crestal bone resorption around the immediately restored implants in cases of partial edentulism, however a difference of 0.3 mm may not have a clinical impact.

Immediate loading of two unsplinted implants retaining the existing complete mandibular denture in elderly edentulous patients: 1-year results from a multicentre prospective cohort study.

PURPOSE: To evaluate the outcome of two freestanding implants immediately loaded retaining an existing mandibular complete denture in elderly edentulous patients up to 1 year after loading. MATERIALS AND METHODS: 42 patients with a mean age of 76.5 years (range 71 to 89) were selected for stabilising their mandibular complete denture with two implants placed mesial to the mandibular canine position bilaterally. Individual ball abutments were connected and torqued at 30 Ncm and the existing complete denture was immediately attached. No postoperative limitations to chewing function were given. The patients were evaluated clinically and radiographically at implant placement and at 6- and 12-month follow-up examinations. RESULTS: At the 12-month follow-up no implant failed. Peri-implant bone resorption was 0.203 mm (CI 95% 0.322; 0.086) after 6 months and 0.298 mm (CI 95% 0.425; 0.173) after 12 months. Of the 42 cases, 3 had major prosthetic complications and 5 patients required minor extra maintenance appointments. CONCLUSIONS: Within the limits of this study, it can be suggested that the immediate loading of two unsplinted implants retaining the existing complete mandibular denture in elderly patients can result in favourable implant survival and peri-implant bone healing, however larger and longer follow-ups of 5 years or more are needed.

Immediate loading of single post-extractive implants in the anterior maxilla: 12-month results from a multicenter clinical study.

The purpose of the study was to evaluate survival and peri-implant bone levels of single, immediately loaded post-extractive implants in the anterior maxilla 12 months after implant placement. Thirty-six consecutive patients from 3 study centers were included in the study. The concerned sites were upper premolars, canines, and incisors. For each patient the following data were recorded: reason for tooth extraction, bone quality, implant size, and final insertion torque. Implants were placed using a flapless technique and immediately loaded with a nonoccluding temporary restoration. Final restorations were provided 4 months later. Peri-implant bone resorption was evaluated radiographically after 6 and 12 months. The average final insertion torque was 70.55 Ncm. One implant inserted in D3 quality bone with a 35-Ncm seating torque was lost. All other implants had a final insertion torque ranging between 50 and 80 Ncm. The average peri-implant bone loss was 0.437 and 0.507 mm at 6 and 12 months, respectively. All the sites maintained excellent papillae and peri-implant soft-tissue conditions. The resulting 1-year success rate was 97.2%. Immediate nonfunctional loading of single post-extractive implants in the anterior maxilla is a predictable treatment. And it seems that achieving high insertion torques by placing self-tapping/self-condensing implants in an underprepared osteotomy is favorable.

Survival and success rates of immediately and early loaded implants: 12-month results from a multicentric randomized clinical study.

Our objective was to compare survival and peri-implant bone levels of immediately nonocclusally vs early loaded implants in partially edentulous patients up to 12 months after implant placement. Eighty patients (inclusion criteria: general good health, good oral hygiene, 30-65 years old; exclusion criteria: head and neck irradiation/cancer, pregnancy, uncontrolled diabetes, substance abuse, bruxism, lack of opposing occluding dentition, smokers >10 cigarettes/day, need for bone augmentation procedures) were selected in 5 Italian study centers and randomized into 2 groups: 40 patients in the immediately loaded group (minimal insertion torque 30 Ncm) and 40 patients in the early loaded group. Immediately loaded implants were provided with nonoccluding temporary restorations. Final restorations were provided 2 months later. Early loaded implants were provided with a definitive restoration after 2 months. Peri-implant bone resorption was evaluated radiographically with software (ImageJ 1.42). No dropout occurred. Both groups gradually lost peri-implant bone. After 12 months, patients of both groups lost an average of 0.4 mm of peri-implant bone. There were no statistically significant differences (evaluated with t test) between the 2 loading strategies for peri-implant bone level changes at 2 (P = .6730), 6 (P = .6613) and 12 (P = .5957) months or for survival rates (100% in both groups). If adequate primary stability is achieved, immediate loading of dental implants can provide similar success rates, survival rates, and peri-implant bone resorption as compared with early loading, as evaluated in the present study.