Immediate loading of three (fixed-on-3) vs four (fixed-on-4) implants supporting cross-arch fixed prostheses: 1-year results from a multicentre randomised controlled trial.

PURPOSE: To evaluate the outcome of three (fixed-on-3 = Fo3) vs four (fixed-on-4 = Fo4) implants immediately restored with metal-resin screw-retained cross-arch prostheses in fully edentulous jaws. MATERIALS AND METHODS: Forty-eight edentulous or to be rendered edentulous patients were randomised in six centres (eight patients per centre) to the Fo3 group (24 patients: 12 maxillae and 12 mandibles) and to the Fo4 group (24 patients: 12 maxillae and 12 mandibles) according to a parallel group design. To be immediately loaded, implants had to be inserted with a minimum torque of 40 Ncm. Outcome measures were prosthesis and implant failures, complications and peri-implant marginal bone level changes evaluated up to 1 year post-loading. RESULTS: One maxillary prosthesis per group was delayed loaded because implants could not be placed with a torque of at least 40 Ncm. Ten patients in the Fo3 group and four in the Fo4 group had implants placed flapless. One year after loading no drop out occurred. One patient of the Fo3 group lost three implants vs three patients of the Fo4 group who lost four implants, the difference being no statistically significant (risk difference = -0.08; 95% CI: -0.27 to 0.10; Fisher's exact test P = 0.609). One mandibular Fo3 and one maxillary Fo4 prosthesis failed. Six Fo3 patients were affected by complications vs three Fo4 patients (risk difference = 0.12; 95% CI: -0.10 to 0.34; Fisher's exact test; P = 0.461). Both groups lost marginal bone in a statistically significant way (0.22 ± 0.20 mm for Fo3 patients and 0.40 ± 0.21 mm for Fo4 patients), with Fo3 group showing less marginal peri-implant bone loss than Fo4 group (estimate of the difference = -0.18 (standard error: 0.06) mm; 95% CI: -0.30 to -0.06; P = 0.005). There were no differences in clinical outcomes between the six operators. CONCLUSIONS: These preliminary results suggest that immediately loaded cross-arch prostheses of both jaws can be supported by only three dental implants at least up to 1 year post-loading, though longer follow-ups are definitively needed.

Immediate vs early loading of 6.6 mm flapless-placed single implants: 9 years after-loading report of a split-mouth randomised controlled trial.

PURPOSE: To evaluate the long-term effectiveness of 6.6 mm long flapless-placed single implants loaded immediately or early loaded at 6 weeks. MATERIALS AND METHODS: Thirty patients each received two single Nanotite External Hex Biomet 3i implants, which were then randomly allocated to be either immediately or early loaded, according to a split-mouth design. Implants had to be inserted with a torque superior to 40 Ncm. Provisional crowns were put in slight occlusal contact and replaced by definitive crowns 3 months after loading. Patients were followed for 9 years after loading. Outcome measures were implant failures, biological and biomechanical complications, peri-implant marginal bone level changes and patient preference. RESULTS: A total of 29 implants were immediately loaded, while 31 were early loaded. Nine years after loading, three patients dropped out. One implant failed in each group within 2 months after loading. One patient asked for the immediately loaded crown to be remade for aesthetic reasons and then again to have both metal-ceramic crowns replaced by full ceramic crowns. Another patient had his immediately loaded crown remade after repeated debonding. Six patients from each group experienced complications, the difference being not statistically significant (difference of proportions = 0.00; 95% CI -0.20 to 0.20, P = 1.000). Peri-implant bone loss was 0.60 mm for patients with immediately loaded implants and 0.46 mm for early loaded ones, which was not significantly different (mean difference = 0.14 mm, 95% CI -0.13 to 0.41, P = 0.283). All but one patient had no preference for either procedure after 9 years. CONCLUSIONS: Flapless-placed 6.6 mm long single implants can be immediately loaded and remain successful up to 9 years after loading. Conflict-of-interest statement:

Immediate loading of two flapless placed mandibular implants supporting cross-arch fixed prostheses: A 5-year follow-up prospective single cohort study.

PURPOSE: To evaluate the clinical outcome of two implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses 5 years after loading. MATERIALS AND METHODS: Eighty consecutive patients were recruited. To be immediately loaded, implants had to be inserted with a minimum torque of 80 Ncm. Forty-six laser-welded titanium and 34 cast silver-palladium frameworks with resin teeth were initially delivered within 8 and 48 h, respectively. Outcome measures, evaluated by two independent assessors included prosthesis and implant failures, complications, marginal bone level changes, implant stability quotient (ISQ) values and patient satisfaction. RESULTS: Five years after loading one patient did not return to the control and 10 prostheses were remade. Two implants failed early in two patients, but they were successfully replaced. Thirty-six complications occurred in 28 patients but were all successfully treated. After 5 years, mean marginal bone loss was 0.69 mm, mean ISQ values decreased from 75.4 to 73.8, and all patients were fully satisfied with the therapy. A post-hoc comparison between the outcome of laser-welded and cast frameworks showed that laser-welded frameworks were affected by significantly more complications (19 patients out of 46 and 6 patients out of 34, respectively; difference in proportion = 0.23, 95% CI: 0.03 to 0.43; Pearson's chi-square test, P = 0.032), therefore such a framework construction should be considered as a long-term temporary prosthesis and not a definitive prosthesis. CONCLUSIONS: Immediately loaded mandibular cross-arch prostheses can be supported by only two implants up to 5 years, if made with a robust cast framework. Longer follow-ups (around 10 years) are still needed to know the prognosis of this treatment modality.

Machined versus roughened immediately loaded and finally restored single implants inserted flapless: Preliminary 6-month data from a split- mouth randomised controlled trial.

PURPOSE: To compare the outcome of immediately loaded single implants with a machined or a roughened surface. MATERIALS AND METHODS: Fifty patients had two implant sites randomly allocated to receive flaplessplaced single Syra implants (Sweden & Martina), one with a machined and one with a roughened surface (sand-blasted with zirconia powder and acid etched), according to a split-mouth design. To be loaded immediately, implants had to be inserted with a torque superior to 50 Ncm. Implants were restored with definitive crowns in direct occlusal contact within 48 h. Patients were followed for 6 months after loading. Outcome measures were prosthetic and implant failures and complications. RESULTS: Two machined implants and four roughened implants were not loaded immediately. Six months after loading no dropout occurred. One implant loaded late, which had a rough implant surface, failed 20 days after loading (P (McNemar test) = 0.625; difference in proportions = -0.04; 95% CI: -0.15 to 0.07). Three crowns had to be remade on machined implants and four on roughened implants (P (McNemar test) = 1.000; difference in proportions = -0.02; 95% CI: -0.12 to 0.08). Three machined and five roughened implants experienced complications (P (McNemar test) = 0.625; difference in proportions = -0.04; 95% CI: -0.15 to 0.07). There were no statistically significant differences between groups for crown and implant losses as well as complications. CONCLUSIONS: Up to 6 months after loading both machined and roughened flapless-placed and immediately loaded single implants provided good and similar results, however, longer follow-ups are needed to evaluate the long-term prognosis of implants with different surfaces.

Immediate loading of two flapless placed mandibular implants supporting cross-arch fixed prostheses: a 3-year follow-up prospective single cohort study.

PURPOSE: To evaluate the clinical outcome of two implants placed flapless in fully edentulous mandibles and immediately restored with a metal-resin screw-retained cross-arch prostheses 3 years after loading. MATERIALS AND METHODS: Eighty consecutively patients were recruited. Implants for immediate loading had to be inserted with a minimum torque of 80 Ncm. Outcome measures, evaluated by two independent assessors, were: prosthesis and implant failures, complications, marginal bone level changes, implant stability quotient (ISQ) values and patient satisfaction. RESULTS: Three years after loading, all prostheses were in function although one patient did not come back for the 1- and 3-year follow-ups. Two implants failed early in two patients, but were successfully replaced and their prostheses remade. Twelve complications occurred in 10 patients but were all successfully treated. After 3 years, mean marginal bone loss was 0.43 mm, mean ISQ values decreased from 75.4 to 75.3, and all but four patients were fully satisfied with the therapy. Four patients were partially satisfied because, lacking molars, they could not chew as they wished. CONCLUSION: Immediately loaded mandibular cross-arch partial dentures can be supported by only two dental implants up to 3 years. Longer follow-ups (around 10 years) are needed to know the prognosis of this treatment modality.

Immediate loading of 2(all-on-2) versus 4 (all-on-4) implants placed with a flapless technique supporting mandibular cross-arch fixed prostheses: 1-year results from a pilot randomised controlled trial.

PURPOSE: To evaluate the outcome of 2 versus 4 implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses. MATERIALS AND METHODS: Sixty patients from two different centres were randomised: 30 to the allon- 2 group and 30 to the all-on-4 group according to a parallel group design. To be immediately loaded, implants had to be inserted with a minimum torque of 40 Ncm. Outcome measures were prosthesis and implant failures, complications, and marginal bone level changes. RESULTS: Flaps were raised in 18 patients. A total of 2 implants in 2 patients did not reach the planned insertion torque and were immediately replaced by larger diameter ones. One year after loading, no drop-out or implant failure occurred. Eight biomechanical complications occurred in the all-on-2 group versus 8 complications in the all-on-4 group. There were no statistically significant differences for complications between groups. There were no statistically significant differences for marginal peri-implant bone levels between the two groups (estimate of the difference = -0.16; 95%CI -0.40 to 0.08; P (ANCOVA) = 0.074), with both groups losing a statistically significant amount of marginal bone (0.74 mm for all-on-2 implants and 0.58 mm for all-on-4 implants). There were statistically significant differences between the two centres, with more bone being lost for the Bologna centre (0.26 mm versus 1.07 mm). CONCLUSIONS: These preliminary results, up to 1 year after loading, suggest that immediately loaded mandibular cross-arch fixed prostheses can be supported by only 2 dental implants. Longer followups (approximately 10 years) are needed to properly evaluate this therapeutic option.

Immediate loading of 2 (all-on-2) flapless-placed mandibular implants supporting cross-arch fixed prostheses: interim data from a 1-year follow-up prospective single cohort study.

PURPOSE: To evaluate the clinical outcome of 2 implants placed flapless in fully edentulous mandibles and immediately restored with a metal-resin screw-retained cross-arch prosthesis 1 year after loading. MATERIALS AND METHODS: Eighty consecutive patients were recruited. To be immediately loaded, implants had to be inserted with a minimum torque of 80 Ncm. Outcome measures, evaluated by two independent assessors, were prosthesis and implant failures, complications, marginal bone level changes, implant stability quotient (ISQ) values and patient satisfaction. RESULTS: Flaps were raised in 7 patients. Twelve implants in 7 patients did not reach the planned insertion torque. Four implants in 3 patients were immediately replaced by larger diameter implants and achieved the desired torque, whereas the remaining implants were immediately loaded anyway. Two implants failed early in 2 patients, but were successfully replaced and their prostheses remade. One month after loading, 72 (90%) patients declared to be completely satisfied with the therapy, 7 (9%) partially satisfied and 1 (1%) unsatisfied. One year after loading, all prostheses were in function, though one patient did not attend the 1-year control. Eight (10%) complications occurred, all successfully treated. After 1 year, the mean marginal bone loss was 0.3 mm and mean ISQ values decreased from 75.4 to 72.4. CONCLUSIONS: These short-term results at 1 year after loading suggest that immediately loaded mandibular cross-arch fixed prostheses can be supported by only 2 dental implants. Longer follow-ups (around 10 years) are needed to know the prognosis of this treatment modality.