A prospective multicenter study using two different surgical approaches in the mandible with turned Brånemark implants: conventional loading using fixed prostheses. One-stage operative procedure using two different implant systems: a prospective study on implant overdentures in the edentulous mandible. Restoration of partially edentulous patients using dental implants with a microtextured surface: a prospective comparison of delayed and immediate full occlusal loading. Vertical bone augmentation versus 7-mm-long implants in posterior atrophic mandibles. Results of a randomised controlled clinical trial of up to 4 months after loading. Immediate nonocclusal versus early loading of dental implants in partially edentulous patients: 1-year results from a multicenter, randomized controlled clinical trial. Submerged or non-submerged healing of endosseous implants to be used in the rehabilitation of partially dentate patients. Early loading of ITI implants supporting a maxillary full-arch prosthesis: 1-year data of a prospective, randomized study. Bone augmentation versus 5-mm dental implants in posterior atrophic jaws. Four-month post-loading results from a randomised controlled clinical trial. Nonsubmerged and submerged implants in the treatment of the partially edentulous maxilla.
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.
                To evaluate the submerged and nonsubmerged surgical techniques when treating mandibular edentulism using a submerged implant system, with regard to implant survival and complications.
                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.
                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.
                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. Evidence-based reports are needed to support the application of a one-stage surgical protocol for unsplinted implants supporting mandibular overdentures.
                To examine the feasibility and success of using two different dental implant systems (originally designed for two-stage operative technique) using a one-stage operative procedure in patients being rehabilitated with implant mandibular overdentures.
                The study sample involved 24 edentulous subjects (aged 55-80 yr) randomly allocated to two different implant systems, one with a machined titanium implant surface (Steri-Oss, Nobel Biocare, Göteborg, Sweden) and the other with a roughened titanium surface (Southern Implants, Ltd., Irene, South Africa). Two unsplinted implants to support implant overdentures were placed in the anterior mandible of all patients, using a standardized one-stage surgical and prosthodontic procedure. Primary stability and bicortical anchorage of the implants was mandatory before healing abutments were connected at the time of implant placement. Implant overdentures and their respective matrices were inserted following a standard 12-week healing period. Data relating to mobility tests, radiographs, and peri-implant parameters were documented at 12, 16, and 52 weeks after surgery.
                A success rate of 95.8% for the Steri-Oss and 100% for the Southern Implants was found, without any statistically significant differences in the marginal bone loss. Significant changes in Periotest values were observed for both types between 12 and 52 weeks (p < .001). Minor changes were observed in the peri-implant parameters evaluated.
                These preliminary findings show a successful application of this one-stage approach for unsplinted implants supporting mandibular overdentures with Steri-Oss and Southern Implant Systems. The aim of this study was to determine the clinical effectiveness of placing dental implants with microtextured surfaces into full occlusal loading at the time of placement in partially edentulous patients.
                Two demographically similar groups of 14 patients each were treated with a total of 92 Spline Twist Implants (Centerpulse Dental, Carlsbad, CA). Test implants were placed into immediate full occlusal loading, and control implants were restored using a conventional delayed loading procedure. Otherwise, both groups of patients received similar therapy from the same treatment team. Radiographs, periodontal indices, and Periotest values were recorded every 6 months during routine clinical follow-up appointments. The mean loading time for all prostheses was 24 months at the time of this report.
                No implants failed in the test group, and 1 implant failed before loading in the control group. Cumulative implant success was 98.9% for all implants placed (test group = 100%; control group = 92.9%). Periodontal measurements indicated no significant clinical differences between implants placed into immediate full occlusal loading and those loaded via a conventional delayed protocol.
                Immediate full occlusal loading of partial prostheses supported by microtextured implants in partially edentulous patients demonstrated excellent clinical results, with no adverse periodontal effects after 24 months of function. Additional follow-up will provide invaluable information on the long-term effects of this technique.
                Immediate full occlusal loading of partial prostheses supported by microtextured implants can be successfully achieved for 24 months in highly motivated patients with excellent oral hygiene. To evaluate whether 7-mm-long implants could be a suitable alternative to longer implants placed in vertically augmented bone for the treatment of atrophic posterior mandibles.
                Sixty partially edentulous patients having 7 to 8 mm of residual crestal height and at least 5.5 mm thickness measured on a computed tomography scan above the mandibular canal were randomised to receive either two to three submerged 7-mm-long NanoTite External Hex implants (Biomet 3i) or 10-mm or longer implants (30 patients per group) placed in vertically augmented bone. Bone was augmented with anorganic bovine bone blocks (Bio-Oss) using a sandwich technique and resorbable barriers. The grafts were left healing for 5 months before placing the implants, which were submerged. Four months after implant placement, provisional acrylic prostheses were delivered. Definitive screw-retained metal-ceramic prostheses were delivered 4 months later. Outcome measures were: prosthesis and implant failures, any complications, and time needed to fully recover mental nerve sensitivity. All patients were followed up to the delivery of the final restorations (4 months after loading).
                No patient dropped out. In two patients of the augmented group, there was not enough space to place 10-mm or longer implants as planned and 7-mm-long implants were used instead. The most likely reason for this is that the Bio-Oss blocks fractured in many pieces at placement. One prosthesis could not be placed when planned in the 7-mm group versus three prostheses in the augmented group, because of failure of one implant in each patient. The difference was not statistically significant. All implants were successfully replaced and final prostheses delivered. Four complications (wound dehiscence) occurred during graft healing in the augmented group (one possibly associated with the failure of one implant) versus none in the 7-mm-long implant group. The difference was not statistically significant. No patient suffered from permanent paraesthesia of the alveolar inferior nerve; however, sensitivity was recovered significantly faster in the short implant group.
                The early results of this study suggest that, when the residual bone height over the mandibular canal is between 7 and 8 mm, 7-mm short implants might be a preferable choice since the treatment is faster, cheaper and associated with less morbidity than vertical bone augmentation. These preliminary results must be confirmed by follow-ups of 5 years or more in order to monitor the performance of short implants over time. To compare the efficacy of immediate nonocclusal loading (test group) versus early loading (control group) in partially edentulous patients.
                Fifty-two patients in 5 Italian private practices were randomized to 1 of the treatments: 25 to the immediately loaded group and 27 to the early loaded group. To be immediately loaded, single implants had to be inserted with a torque of > 30 Ncm, and splinted implants had to be inserted with a torque of > 20 Ncm. Implants in the immediately loaded group were provided with full acrylic resin nonoccluding temporary restorations within 48 hours after placement. After 2 months, full occluding provisional restorations were provided. Implants in the early loading group were not submerged and were loaded after 2 months. At 8 months, provisional restorations were replaced with definitive metal-ceramic prostheses. Outcome measures were prosthesis and implant failures as well as biologic and prosthetic complications recorded by nonblinded assessors. The Fisher exact test was used to compare the proportion of implant failures.
                Fifty-two implants were placed in the immediately loaded group and 52 in the early loaded group. No dropouts or complications occurred up to 14 months postinsertion. One single implant failed in the immediately loaded group 2 months after placement. There was no statistically difference for the tested outcome measures between the 2 procedures (P > .99).
                The results of this randomized controlled clinical trial with 25 patients rehabilitated with immediately restored nonocclusally loaded implant-supported prostheses compared to 27 patients restored 2 months following placement suggest that there are no major clinical differences in implant survival between these 2 protocols. No biologic or prosthetic complications occurred. To evaluate bone-level alterations that occurred at implants of the Astra Tech(R) System that were placed in the load carrying, posterior parts of the dentition using either a submerged (two-stage) or a non-submerged (one-stage) installation protocol.
                Eighty-four patients that required 115 fixed partial dentures (FPDs or cases) entered the prospective study. All subjects were assigned one patient and > or =one case numbers. For the randomization of cases, a custom-made program based on balanced random permuted blocks was utilized. The cases were assigned to two treatment groups, namely one-stage installation procedure, non-submerged technique (group A) and two-stage installation procedure, submerged technique (group B). Several subjects contributed with cases to both groups A and B. Periodontal, endodontal and open caries lesions were treated prior to implant installation. All patients received careful oral hygiene instruction and training in self-performed plaque control measures. The surgical technique used for fixture installation followed the outline described in the manual for the Astra Tech System. The FPDs were placed 3 months (mandible) and 6 months (maxilla) following implant installation. Immediately following FPD placement, a baseline examination was performed that included assessment of plaque, soft-tissue inflammation and bone level. Clinicians who were otherwise not involved in the study performed the radiographic measurements. Clinical and radiographical examinations were repeated once a year after the baseline examination.
                The primary outcome variable was the change in the bone level at the implants from the time of placement of the bridge (FPD) to the 1- and 2-year reexaminations. Fisher's permutation test was used to test if differences existed between groups A and B, and between patients (men/women, smokers/non-smokers, age), sites (maxilla/mandible) and implants (length, diameter). Pitman's test was used to study correlations between bone shape and quality data and different radiographic bone-level data.
                It was demonstrated that tissue healing following implant installation appeared to be independent of the surgical protocol, i.e. whether the marginal portions of the implants during surgery were fully or only partly submerged under the ridge mucosa. Thus, (i) in both treatment groups the number of implants that failed to osseointegrate (early failures) was small (<2%); (ii) at the end of the recommended periods of bone healing prior to loading, - in both groups, maxilla=6 months and mandible=3 months - the level of the marginal bone was close to the coronal rim of the fixture; group A: 1.54+/-0.92 mm, group B: 1.31+/-0.77 mm. The current study also demonstrated that irrespective of surgical protocol (two-stage, one-stage), implants supporting the FPDs exhibited only small amount of radiographic bone loss during the first year of function (group A: 0.02+/-038 mm, group B: 0.17+/-0.64 mm). Moreover, during the second year of function, the amount of additional bone loss that occurred in the two treatment groups was close to zero.
                Periimplant bone-level change during function seemed to be unrelated to whether initial soft- and hard-tissue healing following implant installation had occurred under submerged or non-submerged conditions. This prospective, randomized study investigated the safety, feasibility, and reliability of the early loading of implants in edentulous maxillae.
                Twenty-four patients with completely edentulous maxillae were randomized into a test group (n = 16) and a control group (n = 8). All patients received 5 or 6 solid screw-type titanium implants. These were loaded with full-arch prostheses after 9 to 18 days in the test group and after 2.5 to 5.1 months in the control group. Periapical radiographs were taken and routine clinical assessments were made at loading, after 6 months, and after 12 months.
                The implant survival rate 1 year after loading was 100%. Modified Plaque index scores and Sulcus Bleeding index scores were better in the test group than in the control group (P < or = .05). There was a significant difference in peri-implant bone height between the 2 groups (P < .001) and this difference converged with time (P < .001).
                This clinical, prospective, randomized, controlled study fulfilled the criteria for a comparable study. Owing to the small patient sample, the conclusions drawn were based on feasibility analyses of the results. Standard materials and methods were used. Only patients with maxillary bone of sufficient height and width were selected. The use of a single operator in each discipline--maxillofacial surgery, prosthodontics, and dental technology--may have improved the chances of achieving consistent standards and opinions.
                These results indicate that early loading in selected patients was as safe and reliable as delayed loading in this small patient population and may offer a satisfactory alternative to the standard protocol. To evaluate whether short (5 mm) dental implants could be a suitable alternative to augmentation and placement of longer implants (10 mm) in posterior atrophic jaws.
                Thirty partially edentulous patients with bilateral posterior edentulism were included: 15 patients having 5 to 7 mm of residual crestal height above the mandibular canal, and 15 patients having 4 to 6 mm of residual crestal height below the maxillary sinus and bone thickness of at least 8 mm measured on a CT scan. The patients were randomised either to receive one to three submerged 5-mm-long Rescue implants (Megagen) or 10-mm-long implants placed in augmented bone according to a split-mouth design. Mandibles were augmented with interpositional anorganic bovine bone blocks (Bio-Oss) and maxillae with granular Bio-Oss placed through a lateral window under the lifted sinus membrane. Resorbable barriers were used to cover the grafted sites. Grafts were left to heal for 4 months before placing the implants using a submerged technique. Four months after implant placement, provisional reinforced acrylic prostheses were delivered and replaced 4 months later by definitive screw-retained metal-ceramic prostheses. Outcome measures were: prosthesis and implant failures, any complications, time needed to fully recover mental nerve function (only for mandibular implants) and patient preference assessed 1 month after loading. All patients were followed up to delivery of the final restorations (4 months after loading).
                A systematic deviation from the research protocol occurred: the operator used another implant system (EZ Plus, Megagen) for implants 10 mm or longer with a diameter of 4 mm at the augmented sites. No patients dropped out. In 5 patients of the augmented group (all mandibles), there was not enough height to place 10-mm-long implants as planned and shorter implants (7 and 8.5 mm) were used instead. In each group, one prosthesis could not be placed when planned because an implant was found to be mobile at abutment connection: one 5 mm maxillary implant and one 8.5 mm mandibular implant in the augmented group. Five complications occurred: two in the augmented group (one maxillary sinus perforation and one mandibular wound dehiscence after implant placement possibly associated with the failure of one implant) versus three maxillary sinus perforations in the 5-mm-long implant group. The difference was not statistically significant. No patient suffered from permanent disruption of alveolar inferior nerve function, however, significantly more patients had paraesthesia for up to 3 days in the augmented group. There was no statistically significant difference in patient preference with the majority of patients expressing no preference for which treatment they received, finding both of them acceptable. Dental implants vary in design and surfaces. In addition, different surgical techniques have been used for implant insertion. The ITI Dental Implant System (Straumann AG, Waldenburg, Switzerland) has always required a one-stage technique, whereas the Brånemark System (Nobel Biocare AB, Gothenburg, Sweden) requires a two-stage technique.
                The aim of this study is to compare the outcome of fixed partial bridges in the maxilla supported by both ITI and Brånemark implants in a split-mouth design.
                Twenty-eight patients with a residual anterior dentition in the maxilla were included in this split-mouth study. The Brånemark implants were used on one side and the ITI implants on the other side of the residual dentition according to a randomization procedure. A blocking size of four was used, giving equal probability of placing ITI or Brånemark implants in the right or left side of the jaw. The surgical and prosthetic procedures followed the guidelines given by the manufacturers. The prosthetic treatment with the two-implant systems was performed at the same time, and for that reason the healing period was 6 months for both systems. The observation period for all patients was 1 year after loading.
                Two Brånemark implants (in one patient) were lost before loading, and one ITI implant was lost 1 year after loading. There was no significant difference in survival rate. Radiographic examination of the bone level was performed at the time of delivery of the bridge and after 1 year. The mean marginal bone level at baseline was situated 1.9 mm from the reference point for the Brånemark implants and 1.5 mm for the ITI implants. With regard to the insertion depth used, these bone levels indicate that bone loss had taken place before baseline. However, between baseline and the 1-year examination, there was no significant change of the marginal bone (0.2 +/- 0.08 mm at the Brånemark implants and 0.1 +/- 0.11 mm at the ITI implants). The difference between results with the two implants was not statistically significant. Crater-form bone destructions were seen at some ITI implants, indicating periimplantitis. However, at only two implants were there clinical signs of periimplantitis.
                No significant difference in survival rate or in marginal bone change could be demonstrated between the two systems. At some ITI implants (18%), crater-form bone loss was observed.
The number of patients included in the trials was too small to draw definitive conclusions. The 1-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a 2-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability or when barriers are used for guided tissue regeneration, or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments especially in fully edentulous patients.