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Odontogenic keratocysts are significant cysts of the jaw that are characterized by aggressive behavior and a high tendency to recur. The treatments of choice may be radical or conservative, and in the literature a debate is still open about the gold standard in the treatment of OKCs.This report describes a wide multilocular OKC extended in the right mandibular ramus and illustrates atypical behavior of a cystic lobe after marsupialization, not found to our knowledge in the previous literature. Moreover, an orthognathic procedure, consisting of sagittal osteotomy was chosen for the excision of the cyst to preserve as much bone as possible and the integrity of the inferior alveolar nerve.

PURPOSE: To present a case of a woman referred for the management of displacement of one implant in her right posterior mandible that had occurred three days previously. MATERIALS AND METHODS: After implant placement, the practitioner was no longer able to detect the implant and inserted a second one at the same site without taking a control radiograph. At the end of surgery, when a radiograph was finally taken, the first implant appeared displaced into the mandible body. The patient suffered total paresthesia on the right lower lip and chin. A flap was raised and bone osteotomies were performed on the lateral side of the mandible to create a rectangular cortical bone window that was removed. The implant was stuck by the second implant placed coronally, and only after unscrewing this second implant was it possible to remove the first one. RESULTS: After 18 months, the patient recovered full sensitivity. CONCLUSIONS: In cases of implant displacement, it is always recommended that appropriate radiographs are performed to visualise where the implants could have been displaced in order to avoid more serious consequences.

International audience; Purpose To evaluate whether 4.0 mm short dental implants could be an alternative to augmentation with xenographs in the maxilla and placement of at least 10.0 mm long implants in posterior atrophic jaws. Materials and methods A group of 40 patients with atrophic posterior (premolar and molar areas) mandibles with 5.0 mm to 6.0 mm bone height above the mandibular canal and 40 patients with atrophic maxillas having 4.0 mm to 5.0 mm below the maxillary sinus, were randomised according to a parallel group design to receive between one and three 4.0 mm long implants or one to three implants of at least 10.0 mm long in augmented bone, at two centres. All implants had a diameter of 4.0 mm or 4.5 mm. Mandibles were vertically augmented with inter-positional equine bone blocks and resorbable barriers. Implants were placed 4 months after the inter-positional grafting. Maxillary sinuses were augmented with particulated porcine bone via a lateral window covered with resorbable barriers, and implants were placed simultaneously. Implants were not submerged and were loaded after 4 months with provisional screw-retained reinforced acrylic restorations replaced after another 4 months by definitive screw-retained metal-composite prostheses. Patients were followed up to 1 year post-loading. Outcome measures were prosthesis and implant failures, any complication, and peri-implant marginal bone level changes. Results Three patients dropped out; one from the maxillary augmented group, one from the mandibular augmented group, and one from the maxillary short implant group. In six augmented mandibles (30%) it was not possible to place implants of at least 10.0 mm, so shorter implants were placed instead. In mandibles, one implant from the augmented group failed vs two 4.0 mm implants in two patients from the short implant group. In maxillae, three short implants failed in two patients vs seven long implants in four patients (two long implants and one short implant dropped into the maxillary sinus). Two prostheses on short implants (one mandibular and one maxillary) were placed at a later stage because of implant failures, vs six prostheses (one mandibular and five maxillary) at augmented sites (one mandibular prosthesis not delivered, three maxillary prostheses delivered with delays, one not delivered, and one failed) at augmented sites. In particular, three patients in the augmented group (one mandible and two maxillae) were not wearing a prosthesis. There were no statistically significant differences in implant failures (P (chi-square test) = 0.693; difference in proportion = 0.03; CI 95% -0.11 to 0.17) or prostheses failures (P (chi-square test) = 0.126; difference in proportion = 0.10; CI 95% -0.03 to 0.24). At mandibular sites, nine augmented patients were affected by complications vs two patients treated with short implants (P (chi-square test) = 0.01; difference in proportion = 0.37; CI 95% 0.11 to 0.63), the difference being statistically significant. No significant differences were found for maxillae nine sinus-lifted patients vs four short implant patients were affected by complications (P (chi-square test) = 0.091; difference in proportion = 0.25; CI 95% -0.03 to 0.53). At 1-year post-loading, average peri-implant bone loss was 0.51 mm at 4 mm long mandibular implants, 0.77 mm at 10 mm or longer mandibular implants, 0.63 mm at short maxillary implants and 0.72 mm at long maxillary implants. The difference was statistically significant in mandibles (mean difference -0.26 mm, 95% CI -0.39 to -0.13, P (ANCOVA) < 0.001), but not in maxillae (mean difference -0.09 mm, 95% CI -0.24 to 0.05, P (ANCOVA) = 0.196). Conclusions One year after loading 4.0 mm long implants achieved similar results, if not better, than longer implants in augmented jaws, but were affected by fewer complications. Short implants might be a preferable choice over bone augmentation, especially in mandibles, since the treatment is less invasive, faster, cheaper, and associated with less morbidity. However, 5 to 10 years post-loading data are necessary before making reliable recommendations. © 2002-2018 Quintessence Publishing Group.

PURPOSE: To evaluate whether short (5.0 to 8.5 mm) dental implants could be a suitable alternative to longer (at least 11.5 mm-long) implants placed in atrophic maxillae augmented with autogenous bone for supporting dental prostheses. MATERIALS AND METHODS: Twenty-eight patients with fully edentulous atrophic maxillae, whom had 5 to 9 mm of residual crestal bone height which was at least 5 mm thick, measured using computerised tomography (CT) scans, were randomised into two groups either to receive 4 to 8 short (5.0 to 8.5 mm) implants (15 patients) or autogenous bone from the iliac crest to allow the placement of at least 11.5 mm-long implants (13 patients). Bone blocks and the windows at the maxillary sinuses were covered with rigid resorbable barriers. Grafts were left to heal for 4 months before placing implants which were submerged. After 4 months, provisional reinforced acrylic prostheses or bar retained overdentures were delivered. Provisional prostheses were replaced, after 4 months, by definitive screw-retained metal-resin cross-arch restorations. Outcome measures were prosthesis and implant failures, any complications, peri-implant marginal bone level changes and patient satisfaction. Patients were followed up to 1 year after loading. RESULTS: All patients were rehabilitated with implant-supported prostheses but two patients dropped out from the augmented group. One bilateral sinus lift procedure failed for infection, although short implants could be placed. One implant failed in the augmented group versus two short implants in two patients (Fishers exact test P = 1.00; difference in proportions = 0.06; 95% CI -0.28 to 0.17). All failures occurred before loading. Significantly more complications occurred in augmented patients: eight complications occurred in 5 augmented patients (all of them complained of pain 1 month after bone harvesting from the iliac crest) versus no complications in the short implant (Fisher's exact test P = 0.013; difference in proportions = 0.38; 95% CI 0.11 to 0.65). Both groups presented a significant peri-implant marginal bone loss at 1 year after loading (P < 0.0001); -1.05 (0.20) mm for short implants and -1.01 (0.16) mm for the augmented group, respectively, with no statistically significant differences between the two groups (mean difference -0.04 mm; 95% CI -0.22 to 0.14; P = 0.59). All patients were fully satisfied with the treatment and would have it again. CONCLUSIONS: This pilot study suggests that short implants may be a suitable, cheaper and faster alternative to longer implants placed in bone augmented with autogenous bone for rehabilitating edentulous atrophic maxillae, however, these preliminary results need to be confirmed by larger trials with follow-ups of at least 5 years.

PURPOSE: To evaluate whether 4.0 x 4.0 mm dental implants could be an alternative to implants at least 8.5 mm long, which were placed in posterior jaws in the presence of adequate bone volumes. MATERIALS AND METHODS: One hundred and fifty patients with posterior (premolar and molar areas) mandibles having at least 12.5 mm bone height above the mandibular canal or 11.5 mm bone height below the maxillary sinus, were randomised according to a parallel group design, in order to receive one to three 4.0 mm-long implants or one to three implants which were at least 8.5 mm long, at three centres. All implants had a diameter of 4.0 mm. Implants were loaded after 4 months with definitive screw-retained prostheses. Patients were followed up to 4-month post-loading and outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone level changes. RESULTS: No patients dropped-out before the 4-month evaluation. Three patients experienced the early failures of one 4.0 mm-long implant each, in comparison to two patients who lost one long implant each (difference in proportion = 0.01; 95% CI -0.06 to 0.09; P = 0.50). Consequently, two prostheses in each group could not be delivered as planned (difference in proportion = 0; 95% CI -0.07 to 0.07; P = 0.69), and one patient from each group is still waiting to have their prostheses delivered. Three short implant patients experienced three complications versus two long implant patients (difference in proportion = 0.01; 95% CI -0.06 to 0.09; P = 0.50). There were no statistically significant differences in prosthesis failures, implant failures and complications. Patients with short implants lost on average 0.38 mm of peri-implant bone at 4 months and patients with long mandibular implants lost 0.42 mm. There were no statistically significant differences in bone level changes up to 4 months between short and long implants (mean difference = 0.04 mm; 95% CI: -0.041 to 0.117; P = 0.274). CONCLUSIONS: Four months after loading, 4.0 x 4.0 mm implants achieved similar results as 8.5 x 4.0 mm-long or longer implants in posterior jaws, however 5 to 10 years post-loading data are necessary before reliable recommendations can be made.

PURPOSE: To compare the effectiveness of 6.0 to 8.0 mm-wide diameter implants, placed immediately after tooth extraction, with conventional 4.0 or 5.0 mm diameter implants placed in a preserved socket after a 4-month period of healing in the molar region. MATERIALS AND METHODS: Just after extraction of one or two molar teeth, and with no vertical loss of the buccal bone in relation to the palatal wall, 100 patients requiring immediate post-extractive implants were randomly allocated to immediate placement of one or two 6.0 to 8.0 mm-wide diameter implants (immediate group; 50 patients) or for socket preservation using a porcine bone substitute covered by a resorbable collagen barrier (delayed group; 50 patients), according to a parallel group design in one centre. Bone-to-implant gaps were filled with autogenous bone retrieved with a trephine drill used to prepare the implant sites for the immediate wide diameter post-extractive implants. Four months after socket preservation, one to two 4.0 or 5.0 mm-wide delayed implants were placed. Implants were loaded 4 months after placement with fixed provisional restorations in acrylic, and replaced after 4 months by fixed, definitive, metal-ceramic restorations. Patients were followed to 1 year after loading. Outcome measures were: implant failures, complications, aesthetics assessed using the pink esthetic score (PES), peri-implant marginal bone level changes, patient satisfaction, number of appointments and surgical interventions recorded, when possible, by blinded assessors. RESULTS: Three patients dropped out 1 year after loading from the immediate group vs six from the delayed group. Five implants out of 47 failed in the immediate group (10.6%) vs two out 44 (4.6%) in the delayed group, the difference being not statistically significant (difference in proportion = 6.0%, 95% CI: -8.8% to 20.8%, P = 0.436). In the immediate group 10 patients were affected by 10 complications, while in the delayed group four patients were affected by four complications. The difference was not statistically significant (difference in proportion = 12%, 95% CI: -2% to 26%, P = 0.084). At delivery of the definitive prostheses, 4 months after loading, the mean total PES score was 9.65 ± 1.62 and 10.44 ± 1.47 in the immediate and delayed groups, respectively. At 1 year after loading, the mean total PES score was 9.71 ± 2.71 and 10.86 ± 1.37 in the immediate and delayed groups, respectively. The Total PES score was statistically significantly better at delayed implants both at 4 months (mean difference = 0.79; 95% CI: 0.05 to 1.53; P = 0.03) and at 1 year (mean difference = 1.15; 95% CI: 0.13 to 2.17; P = 0.02). Marginal bone levels at implant insertion (after bone grafting) were 0.04 mm for immediate and 0.11 mm for delayed implants, which was statistically significantly different (mean difference = 0.07; 95% CI: 0.02 to 0.12; P < 0.0001). One year after loading, patients in the immediate group lost on average 1.06 mm and those from the delayed group 0.63 mm, the difference being statistically significant (mean difference = 0.43 mm; 95% CI: 0.15 to 0.61; P < 0.0001). All patients were fully or partially satisfied both for function and aesthetics, and would undergo the same procedure again both at 4 months and 1 year after loading. Patients from the immediate group required on average 7.48 ± 1.45 visits to the clinician and 2.14 ± 0.49 surgical interventions and to have their definitive prostheses delivered vs 10.30 ± 0.99 visits and 3.08 ± 0.40 surgical interventions for the delayed group, the difference being statistically significant (P < 0.001 for visits, and P < 0.001 for surgical interventions). CONCLUSIONS: Preliminary 1 year follow-up data suggest that immediate placement of 6.0 to 8.0 mm wide diameter implants in molar extraction sockets yielded inferior aesthetic outcomes than ridge preservation and delayed placement of conventional 4.0 to 5.0 mm diameter implants.

PURPOSE: To evaluate clinical safety and effectiveness of a novel calcium-incorporated titanium implant surface (Xpeed, MegaGen Implant Co., Gyeongbuk, South Korea). MATERIALS AND METHODS: Sixty patients were randomised to receive one to six implants in the maxilla with either calcium-incorporated (Xpeed) or control resorbable blasted media (RBM) surfaces, according to a parallel group design at two centres. Implants were submerged and exposed at three different endpoints in equal groups of 20 patients, each at 12, 10 and 8 weeks, respectively. Within 2 weeks, implants were functionally loaded with provisional or definitive prostheses. Outcome measures were prosthesis failures, implant failures, any complications and peri-implant marginal bone level changes. RESULTS: Thirty patients received 45 calcium-incorporated implants and 30 patients received 42 control titanium implants. Three years after loading four patients dropped-out from the Xpeed group and one from the RBM group. No prosthesis or implant failures occurred. There were no statistically significant differences between the groups for complications (P = 0.91; difference in proportions = 0.79 %; 95% CI -0.71 to 2.29) and mean marginal bone level changes (P = 0.88; mean difference = -0.02 mm; 95% CI -0.26 to 0.22). CONCLUSIONS: Both implant surfaces provided good clinical results and no significant difference was found when comparing titanium implants with a nanostructured calcium-incorporated surface versus implants with RBM surfaces.

To evaluate whether 5 × 5 mm dental implants with a novel nanostructured calciumincorporated titanium surface could be an alternative to implants at least 10 mm long placed in bone augmented with bone substitutes in posterior atrophic jaws.A total of 40 patients with atrophic posterior (premolar and molar areas) mandibles having 5 to 7 mm of bone height above the mandibular canal and 40 patients with atrophic maxillae having 4 to 6 mm below the maxillary sinus, were randomised according to a parallel group design to receive one to three 5 mm implants or one to three at least 10 mm-long implants in augmented bone at two centres. All implants had a diameter of 5 mm. Mandibles were vertically augmented with interpositional bovine bone blocks and resorbable barriers. Implants were placed after 4 months. Maxillary sinuses were augmented with particulated porcine bone via a lateral window covered with resorbable barriers and implants were placed simultaneously. All implants were submerged and loaded after 4 months with provisional prostheses. Four months later, definitive screw-retained or provisionally cemented metal-ceramic or zirconia prostheses were delivered. Patients were followed up to 1 year post-loading and the outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone level changes.One maxillary grafted patient dropped out before the 1-year evaluation. In mandibles, 1 grafted patient did not want to go ahead with the treatment because of multiple complications and graft failure, and another grafted patient did not receive his prostheses due the loss of 2 implants. In maxillae, one 5 × 5 mm implant failed with its provisional crown 3 months post-loading. There were no statistically significant differences in prostheses and implant failures. Significantly more complications occurred at both mandibular and maxillary grafted sites: 17 augmented patients were affected by complications versus 8 patients treated with short implants in the mandible (P = 0.0079; difference in proportion = -0.45; 95% CI -0.67 to -0.15), and 5 sinus-lift patients versus none treated with maxillary short implants (P = 0.047; difference in proportion = -0.25; 95% CI -0.44 to -0.06). Patients with mandibular short implants lost on average 0.94 mm of peri-implant bone at 1 year and patients with 10 mm or longer mandibular implants lost 1.03 mm. Patients with maxillary short implants lost on average 0.87 mm of peri-implant bone at 1 year and patients with 10 mm or longer maxillary implants lost 1.15 mm. There were no statistically significant differences in bone level changes up to 1 year between short and longer implants in maxillae (mean difference -0.28 mm, 95% CI -0.56 to 0.01, P = 0.051) and in mandibles (mean difference -0.09 mm, 95% CI -0.26 to 0.08, P = 0.295).One year after loading, 5 × 5 mm implants achieved similar results compared to longer implants placed in augmented bone. Short implants might be a preferable choice to bone augmentation especially in posterior mandibles since the treatment is faster, cheaper and associated with less morbidity, however 5 to 10 years of post-loading data are necessary before making reliable recommendations.MegaGen partially supported this trial and donated implants and prosthetic components used in this study, whereas Tecnoss donated the biomaterials. The data belonged to the authors and by no means did the manufacturers interfere with the conduct of the trial or the publication of its results.

PURPOSE: To compare the effectiveness of immediate post-extractive single implants with delayed implants, placed in preserved sockets after 4 months of healing. Implants that achieved an insertion torque of at least 35 Ncm were immediately non-occlusally loaded. MATERIALS AND METHODS: Just after tooth extraction, and in the presence of less than 4 mm of vertical loss of the buccal bone in relation to the palatal wall, 106 patients requiring a single immediate post-extractive implant in the maxilla from second to second premolar were randomly allocated to immediate implant placement (immediate group; 54 patients) or to socket preservation using anorganic bovine bone covered by a resorbable collagen barrier (delayed group; 52 patients), according to a parallel group design at three different centres. Bone-to-implant gaps were to be filled with anorganic bovine bone, however this was not carried out in 17 patients (corresponding to 40% of those who should have been grafted). Four months after socket preservation, delayed implants were placed. Implants inserted with an insertion torque of at least 35 Ncm were immediately loaded with non-occluding provisional single crowns, then replaced after 4 months by definitive crowns. Patients were followed up to 1 year after loading. Outcome measures were implant failures, complications, aesthetics assessed using the pink esthetic score (PES), peri-implant marginal bone level changes and patient satisfaction recorded by blinded assessors. RESULTS: Nineteen (35%) implants were not immediately loaded in the immediate group versus 39 (75%) implants in the delayed placement group because an insertion torque superior to 35 Ncm could not be obtained. Six patients dropped out 4 months after loading from the delayed group versus none in the immediate group. Two implants failed in the immediate group (6%) versus none in the delayed group, with the difference showing no statistical significance (difference in proportions = 0.04; 95% CI: -0.03 to 0.11; P = 0.187). Eight minor complications occurred in the immediate group and one in the delayed group, and this was statistically significant (difference in proportions = 0.13; 95% CI: 0.03 to 0.23; P = 0.028). At delivery of definitive crowns, 4 months after loading, the mean aesthetic score was 12.8 and 12.6 in the immediate and delayed groups, respectively. At 1 year after loading, the mean aesthetic score was 13.0 and 12.8 in the immediate and delayed groups, respectively. There was no statistically significant difference at 4 months (P = 0.500) and at 1 year (P = 0.615). Marginal bone levels at implant insertion (after bone grafting) were 0.10 mm for immediate implants and 0.02 mm for delayed implants, which did not have a statistically significantly difference (mean difference = 0.08; 95% CI: 0.04 to 0.12; P < 0.001). One year after loading, patients of the immediate group lost on average 0.23 mm and those in the delayed group lost 0.29 mm, the difference being statistically significant (mean difference = -0.06; 95% CI: -0.11 to -0.01; P = 0.036). Patients of both groups were equally satisfied at 4 months as well as at 1 year after loading. CONCLUSIONS: There are more complications with immediate post-extractive implants in comparison to delayed implants. It seems more difficult to obtain an implant insertion torque superior to 35 Ncm in sockets preserved with anorganic bovine bone after a 4-month healing period than with postextractive sites. The aesthetic outcome appears to be similar for both groups.

To evaluate whether 6 mm long by 4 mm wide dental implants could be an alternative to implants at least 10 mm long placed in bone augmented with bone substitutes in posterior atrophic jaws.A total of 20 patients with bilateral atrophic mandibles and 20 patients with bilateral atrophic maxillae, having 5 to 7 mm of bone height above the mandibular canal or below the maxillary sinus, had each side of the jaws randomly allocated according to a split-mouth design. They were allocated to receive one to three 6 mm long and 4 mm wide implants, or implants at least 10 mm long in augmented bone by two different surgeons in different centres. Mandibles were vertically augmented with interpositional equine bone blocks and resorbable barriers, and implants were placed 3 months later. Maxillary sinuses were augmented with particulated porcine bone via a lateral window and implants were placed simultaneously. All implants were submerged and loaded, after 4 months, with provisional prostheses. Four months later, definitive metal-ceramic prostheses were delivered. Outcome measures were prosthesis and implant failures, any complication and radiographic peri-implant marginal bone level changes.One patient treated in the mandible dropped out before the 1-year post-loading follow-up. All maxillary implants and prostheses were successful, whereas 2 mandibular prostheses could not be placed on implants at least 10 mm long due to graft failures; one was associated with the loss of 3 implants because of infection. There were no statistically significant differences in implant and prosthesis failures, though significantly more complications occurred at grafted sites in mandibles (P = 0.0078), but not in maxillae (P = 0.1250). In total, 14 complications occurred in 12 patients at augmented sites versus none at 6 mm-long implants. All failures and complications occurred before loading. Patients with mandibular 6 mm-long implants lost an average of 1.05 mm of peri-implant bone at 1 year and patients with mandibular implants at least 10 mm long lost 1.07 mm. These differences were statistically significant (P0.001). Patients with maxillary 6 mm-long implants lost an average of 1.02 mm of peri-implant bone at 1 year and patients with maxillary implants at least 10 mm long lost 1.09 mm. These differences were statistically significant (P0.001). There were no statistically significant differences in bone level changes up to 1 year between 6 mm and at least 10 mm-long implants in both jaws (mandibles n = 18, mean difference -0.02 mm, 95% CI -0.16 to 0.12, P = 0.7384; maxillae n = 20, mean difference -0.07 mm, 95% CI -0.18 to 0.05, P = 0.2547).Short-term data (1 year after loading) indicate that 6 mm-long implants with a conventional diameter of 4 mm achieved similar if not better results than longer implants placed in augmented bone. Short implants might be a preferable choice to bone augmentation, especially in posterior mandibles since the treatment is faster, cheaper and associated with less morbidity. However, data obtained 5 to 10 years after loading are necessary before making reliable recommendations. CONFLICT OF INTEREST STATEMENT: Tecnoss and Southern Implants partially supported this trial and donated biomaterials, implants and prosthetic components used in this study. However, the data belonged to the authors and by no means did the manufacturers interfere with the conduct of the trial or the publication of its results.

PURPOSE: To compare the clinical effectiveness of two implant systems: Way Milano and Kentron (Geass, Pozzuolo del Friuli, UD, Italy). MATERIALS AND METHODS: A total of 64 patients requiring at least two single crowns or partial fixed dental prostheses supported by a maximum of three implants had their sites randomised according to a split-mouth design to receive both implant systems at six centres. Patients were followed up for 1 year after initial loading. Outcome measures were: prosthesis/implant failures; any complication; peri-implant marginal bone level changes; and clinician preference. RESULTS: In total 71 Way Milano and 73 Kentron implants were placed. Six patients dropped-out before the 1-year follow-up, but all remaining patients were followed up to 1 year post-loading. No Way Milano implant failed, whereas three Kentron implants failed before loading. Two complications were reported, one for each implant type. There were no statistically significant differences for prosthesis/implant failures (difference in proportions = 0.05, P = 0.25; 95% CI -0.02 to 0.13) and complications (difference in proportions = 0, P = 1.0, 95% CI -0.07 to 0.07) between the implant systems. Three operators preferred Way Milano implants whereas the other three had no preference. At implant placement (baseline) bone levels were higher for Way Milano implants (0.27 mm) than for Kentron implants (0.41 mm). Both groups gradually lost statistically significant amounts of periimplant marginal bone at 4 months after loading and at 1 year after loading. One year after loading, Way Milano implants lost an average of 0.73 mm peri-implant bone compared with 0.84 mm of Kentron implants. Marginal bone level changes were not statistically significant different for Way Milano compared to Kentron implants at 4 months (-0.16 mm, 95% CI -0.30, 0.01; P = 0.0606) and 1 year (-0.09 mm, 95% CI -0.26, 0.09; P = 0.3407) after loading. CONCLUSIONS: No statistically significant differences were observed between the two implant types, although three Kentron implants failed versus none of the Way Milano type. Longer follow-up of wider patient populations are needed to better understand whether there is an effective advantage with one of the two implant designs. Conflict of interest statement: This trial was partially funded by Geass (Pozzuolo del Friuli, UD, Italy), the manufacturer of the implants evaluated in this investigation. However, the data belonged to the authors and by no means did the manufacturer interfere with the conduct of the trial or the publication of the results.

Purpose: To evaluate the outcome of two vs four implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses. Materials and Methods: A total of 60 patients from two different centres were randomised: 30 to the fixed-on-2 group and 30 to the fixed-on-4 group according to a parallel group design. To be immediately loaded implants had to be inserted with a minimum torque of 40 Newton/cm (Ncm). Outcome measures were prosthesis and implant failures, complications, and marginal bone level changes. Results: Flaps were raised in 18 patients. Two implants in two patients did not reach the planned insertion torque and were replaced immediately by larger diameter ones. Three years after loading, two patients dropped out from the fixed-on-2 group and one from the fixed-on-4 group. No implant failure or prosthetic failure occurred. A total of 12 fixed-on-2 patients were affected by one complication each vs 13 fixed-on-4 patients. There were no statistically significant differences for complications between groups (difference in proportion = -0.03; 95% CI -29 to 0.22; P [Fisher's exact test] =1.000). There were no statistically significant differences for marginal peri-implant bone loss between the two groups (mean difference = 0.14; CI 95% -0.17 to 0.45; P [ANCOVA] = 0.356), with both groups losing marginal bone in a statistically significant way (1.70 mm for fixed-on-2 implants and 1.56 mm for fixed-on-4 implants). There were statistically significant differences between the two centres, with more bone being lost for the Bologna centre (2.18 vs 1.13 mm; P (ANCOVA) < 0.001). Conclusions: Up to 3 years after loading, these preliminary results suggest that immediately loaded mandibular cross-arch fixed prostheses can be supported by only two dental implants. Longer followups (about 10 years) are needed to properly evaluate this therapeutic option.

PURPOSE: To compare the clinical outcome of fixed prostheses supported by 4- to 8-mm-long implants with prostheses supported by longer implants placed in vertically augmented atrophic mandibles after a follow-up of 5 years in function. MATERIALS AND METHODS: The Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE were searched up to 1st September 2018 for randomised controlled trials (RCTs) with a follow-up of at least 5 years in function comparing fixed prostheses supported by 4- to 8-mm-long implants with prostheses supported by longer implants placed in vertically augmented atrophic mandibles. Outcome measures were prosthesis failure, implant failures, augmentation procedure failures, complications, and peri-implant marginal bone level changes. Screening of eligible studies, assessment of the risk of bias and data extraction were conducted in duplicate and independently by two review authors. The statistical unit of the analysis was the prosthesis. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CIs). RESULTS: Four eligible RCTs that included originally 135 patients were included. Two RCTs had a parallel-group design and two a split-mouth design. Short implants were 5.0 to 6.6 mm long and were compared with longer implants placed in posterior mandibles augmented with interpositional blocks of bone substitutes. All trials were judged at unclear risk of bias. Twelve (14%) bone augmentation procedures failed to achieve the planned bone height to allow placement of implants with the planned length. Five years after loading, 28 patients (21%) had dropped out from the four RCTs. There were no differences for patients having prosthesis (RR = 1.46; 95% CI: 0.52 to 4.09; P = 0.47; I2 = 0%) or implant (RR = 1.00; 95% CI: 0.31 to 3.21; P = 1.00; I2 = 0%) failures between the two interventions, but there were more patients experiencing complications (RR = 4.72; 95% CI: 2.43 to 9.17; P < 0.00001; I2 = 0%) and peri-implant marginal bone loss (mean difference = 0.60 mm; 95% CI: 0.36 to 0.83; P < 0.00001; I2 = 45%) at longer implants in augmented bone. CONCLUSIONS: Five years after loading, prosthetic and implant failures were similar between the two interventions, but complications and peri-implant marginal bone loss were higher and more severe at longer implants placed in vertically augmented mandibles. Larger trials and longer follow-ups up to 10 years after loading are needed to confirm or reject the present preliminary findings. However in the meantime short implants could be the preferable option.

This case report describes the minimally invasive full fixed rehabilitation of a totally edentulous severely atrophic mandible. The patient refused to undergo any other treatment, from the reconstructive surgery to the removable prosthesis, and asked for a fixed minimally invasive solution in the shortest possible time. Considering that the posterior mandibular bone was inadequate in height and that the interforaminal bone was only 4.3 to 5 mm in height, the patient received four 4-mm-ultrashort implants in the interforaminal area that were immediately loaded. Within all the limitations of this case report this procedure in this specific case appears successful through 2 years of loading.

Background: Short implants (up to 5-mm long) have shown good results when compared to longer implants placed in augmented bone. Purpose: To evaluate if 4-mm ultrashort implants could also be an alternative to bone augmentation in the severely atrophic posterior jaws. The primary aim of the study was to compare implant survival rates between study groups. Materials and Methods: Eighty partially edentulous patients with posterior atrophic jaws (5–6 mm of bone above the mandibular canal and 4–5 mm below the maxillary sinus) were included: 40 patients in the maxilla and 40 in mandible. The patients were randomized to receive one to three 4-mm ultrashort implants or one to three implants at least 10-mm long in augmented bone. Results are reported 5 years after loading with the following outcome measures: implant and prosthetic failures, complications and peri-implant marginal bone level changes. Results: Thirty-two complications were reported for the control group in 18 patients versus 13 complications in 10 patients in the test group, the difference being not statistically significant (p= 0.103). In the augmented group, 12 implants failed in 6 patients versus 7 short implants in 6 cases, and 9 prostheses failed in the control group while 4 in the test one, without statistically significant differences (p= 1.000 and 0.363, respectively). At 5 years after loading, short implants lost on average 0.58 ± 0.40 mm of peri-implant marginal bone and long implants 0.99 ± 0.58 mm, the difference was statistically significant (p= 0.006). Conclusion: Four-millimeter ultrashort implants showed similar if not better results when compared to longer implants placed in augmented jaws 5 years after loading. For this reason, their use could be in specific cases preferable to bone augmentation since the treatment is less invasive, faster, cheaper and associated with less morbidity. However, longer follow-ups and larger trials are needed.

Human body dissection was a ubiquitous practice in the past, to better understand anatomy and to develop medicine. Today, its role could still be important to answer everyday clinical queries and help surgeons. The example of the possible lack of anesthesia during symphysis surgeries can emphasize the usefulness of dissection. The mandibular symphysis usually receives innervation from inferior alveolar nerve terminations, but, in some rare cases, a particular anastomosis involves the lingual nerve and the nerve to the mylohyoid. The anatomical knowledge resulting from body dissections could help oral surgeons to understand the reason why the patient could feel pain during the surgery, and ensure performance of the right lingual nerve block to obtain complete anesthesia. This clinical situation shows the educational role of an ancient, yet still valid, practice, human dissection, and the importance of anatomical studies to improve surgical skills, to provide better treatment for the patient.

Featured Application: The proposed protocol, starting from a careful prediction of the final result with the ideal relationship between the prosthesis and soft tissues, aims to improve the GBR approach, particularly for critical atrophies. Background: Treating extended alveolar defects is challenging for their irregular shape and lack of hard and soft tissues. Virtual planned guided bone regeneration (GBR) with customized meshes aims to optimize the treatment by reducing the risk of dehiscence. The mucosa characteristics are crucial in preserving the bone graft covering and vitality. Methods: Two three-dimensional and extended defects, a mandibular posterior and anterior maxillary atrophy were reconstructed with a particulate graft and a digitally customized scaffold. The workflow entailed merging the pre-operatory clinical related data from intra-oral scanning with the radiologic ones from cone beam-CT. A final ideal prediction of the soft tissue relationship with the implant-borne prosthesis was virtually elaborated, conditioning the design of the titanium membrane fitting the bone defects. Results: A good matching between the scaffold and the bone surface was intra-operatory noted; no complications were registered in the first months of healing with complete integrity of the soft tissues above the graft. Conclusions: A careful evaluation of the soft tissues and a forecast of their final relationship with the implant and prosthesis can improve digital mesh/membrane manufacturing with a suitable healing process up to implant placement and loading, favoring peri-implant tissue stability over time.

This case report describes an alternative minimally invasive fixed rehabilitation to approach an impacted maxillary canine (IMC) and the residual deciduous teeth. The patient refused any orthodontic treatment or surgical extraction of the IMC, asking for a fixed and fast option. Considering the available bone was about 5 mm in height, an immediately provisionalized postextractive 4-mm super-short implant was placed. Healing was uneventful. Two years after loading, the result was stable and the patient was fully satisfied. Within all the limitations of this case report, this approach could reduce rehabilitative times, possible complications, and costs.

The aim of this retrospective study was to evaluate clinical and radiographic outcomes of guided bone regeneration (GBR) procedures in the rehabilitation of partially edentulous atrophic arches. A total of 58 patients were included with a follow-up of 3 to 7 years after loading. Data seem to indicate that GBR with nonresorbable membranes can be a good clinical choice and suggest that it could be used to vertically reconstruct no more than 6 mm of bone in the posterior mandible. However, this technique remains difficult and requires expert surgeons.

A 56-year-old female patient with vertical atrophy of the right posterior mandible was treated adopting an interpositional bone block approach using a cancellous heterologous bone block. Osteotomies of the patient’s mandible were performed with the help of dynamic computer-assisted surgery using virtual anatomical patient information obtained from a cone beam computed tomography (CBCT). The use of the dynamic computer-assisted surgery allowed authors to perform the horizontal osteotomy line as planned preoperatively on the CBCT virtual reconstruction, trying to minimize the risks of the inlay technique. No neurological complications were observed after surgery. The inlay technique could benefit from the aid of dynamic navigation technologies in posterior atrophic mandibles, increasing the reproducibility of the technique. A likely safer method for performing osteotomies with the “sandwich” technique in the posterior atrophic mandible is reported.

Prevention of peri-implantitis involves the early diagnosis of peri-implant mucositis. This article presents a protocol of hygienic maintenance in different implant prosthetic scenarios: single crown, fixed partial prosthesis, fixed full-arch, and overdentures. Others clinical conditions have to be taken into consideration: patient compliance; history of periodontitis; implants placed in augmented bone; short, zygomatic, pterygoid, and tilted implants; and complex prosthesis with false gingiva. Two levels of implant maintenance are described: ordinary, performed by dental hygienist, and extraordinary, carried out by both dentist and hygienist. Extraordinary maintenance also involves the removal and decontamination of the prosthetic structure. To obtain an effective prevention of peri-implantitis, one must plan ordinary and extraordinary hygiene in relation to the type of rehabilitation and clinical parameters.

This case report describes an alternative minimally invasive treatment option using 4-mm-long ultrashort implants placed to rehabilitate a severely atrophic edentulous maxilla. The patient, coming from a full removable denture, asked for an implant prosthesis avoiding reconstructive surgeries and expensive procedures. Considering that the mean available bone was about 4.8 mm in height on Cone Beam Computed Tomography (CBCT) scans, 6 implants were placed where bone volumes were sufficient to receive 4-mm-ultrashort implants. Six months after implant placement an implant-supported bar-retained overdenture prosthesis was delivered. The healing process was uneventful and 1 year after loading the result appears clinically and radiographically stable and the patient is fully satisfied. The described approach, despite some prosthetic compromises, within all the limitations of this case report, might be applied in selected cases, reducing rehabilitative times, possible complications and costs. However, longer follow-ups on large number of patients coming from Randomised Controlled clinical Trials (RCTs) are necessary before making more reliable recommendations.

Novel one-piece implants with concave smooth neck have been introduced to promote the formation of a thick mucosal layer and preserve marginal bone. A retrospective study on 70 patients with 1- to 6-year follow-up was carried out. Cumulative survival rates were assessed. Variations of marginal bone level were measured on periapical radiographs as distance of the implant-abutment junction from the bone crest. Influence of different variables on treatment outcome was evaluated. Cumulative success rate after 6 years was 99.4 % at implant level and 98.6 % at patient level. Marginal bone level changed in a significant way over time. After 4 months, an increase of radiographic bone level of 0.173 ± 1.088 mm at implant level and 0.18 ± 1.019 mm at patient level was recorded. Mean marginal bone loss after 5 years was 0.573 ± 0.966 mm at implant level and 0.783 ± 1.213 mm at patient level. Age, sex, smoking habits, implant sites, implant lengths and diameters, prosthetic retentions, and timing of loading did not influence marginal bone remodeling in a statistically significant way. At 4-year follow-up partial restorations lost a mean of 0.96 mm of more marginal bone compared with single restorations. This difference was statistically significant.

This case report describes a successful implant-prosthetic rehabilitation of an atrophic posterior mandible with 4-mm-long implants. The patient refused to undergo any reconstructive surgery, and because the available bone up to the inferior alveolar nerve was only 5 mm or less, the patient received four implants of 4-mm length. Four months after implant placement, a provisional prosthesis was put in place; after another 4 months, this was then in turn replaced with a definitive prosthesis. The use of such short implants allows a fixed prosthetic solution without the need for vertically augmenting the mandibular bone. This procedure considerably reduces intra- and postoperative patient discomfort compared with reconstructive surgery for the placement of longer implants. The follow-up time was 1 year after implant loading.

BACKGROUND: The fixed rehabilitation of patients with severely atrophic maxillae is challenging because of the insufficient bone volumes. The number of complications and failures with bone augmentation procedures is still quite high and sometimes an invasive bone harvesting is required. One solution may be to use zygomatic implants. Prospective studies have shown that zygomatic implants can be used successfully for the rehabilitation of patients with an extreme maxillary atrophy, also with immediate loading. However, the placement of zygomatic implants requires experienced surgeons and it is not risk-free because delicate anatomical structures, such as the orbita and brain, may be involved especially during implant site preparation with drills. Ultrasonic osteotomy allows precise and effective bone cutting without damaging adjacent soft tissues, increasing visibility. Thus, ultrasonic devices may be useful in zygomatic implant surgery, to reduce surgical risks, complications, and morbidity. AIM/HYPOTHESIS: To compare the outcomes of zygomatic implant sites prepared using conventional rotary drills or ultrasonic inserts, for placing 2 zygomatic implants per zygoma according to a split-mouth randomised controlled trial design. MATERIAL AND METHODS: Twenty patients with atrophic fully edentulous maxillae having not sufficient bone volumes (no more than 4 mm of bone height sub-antrally) for placing dental implants at all, were randomised according to a split-mouth design to have 2 zygomatic implant sites prepare with ultrasonic inserts (test side), and 2 zygomatic implant sites prepared with drills (control side), at 2 centres. All zygomatic implants (Southern Implants, Irene, South Africa) had a diameter of 4.3 mm. Implants were immediately loaded (within 24 hours). Patients were followed up to 4 months after loading and outcome measures were: time for site preparation, insertion torque, presence of haematoma, prosthesis and implant failures and any complication. Descriptive statistics were used to summarize the data. Wilcoxon signed rank test compared preparation time, complications, prosthesis and implant failures between the two sides, while McNemar test was used for insertion torque comparison between the tested groups. A Chi-Square Goodness of Fit Test investigated the distribution of haematoma presence and patient preference. All statistical comparisons were conducted at the 0.05 level of significance. RESULTS: Forty treated sides (20 patients) were randomly allocated to each group and 80 zygomatic implants were finally placed; up to 4 months post-loading one patient dropped out; 3 complications occurred in 3 patients at drill sides, while 1 occurred at a ultrasonic side. One patient lost 2 implants at drill side, while no implant was lost in the ultrasonic group (P = 0.317); no prosthetic failures were recorded. Ultrasonic treated sides required a longer preparation time (23.50 minutes) than drills (14.35 minutes) with a statistically significant difference (P = 0.000). Only 1 implant (ultrasonic group) was inserted with a torque

BACKGROUND: Bone augmentation procedures can be associated with significant patient morbidity, can be more expensive and may requires longer times (up to 1 year) before patients are rehabilitated with implant-supported prostheses. Moreover complications, especially for vertical augmentation techniques, are common. AIM/HYPOTHESIS: The aim of this retrospective study was to evaluate whether short (4 mm) dental implants could be a suitable alternative in the failure of reconstructive surgery in the atrophic posterior mandible. MATERIAL AND METHODS: Patients experienced failure in the reconstructive surgery of the atrophic posterior mandible were enrolled. The type of reconstructive surgery, surgical complications, data related to the timing of failure and ways of resolution were collected. For their rehabilitation, super short (4 mm) implants (Twin-Kone"Universal System, Global D, France) with a mean diameter of 4.09 mm were placed. After 4 months, provisional reinforced acrylic prostheses were delivered. Provisional prostheses were replaced, after 4 months, by definitive screw-retained metal-resin restoration. Outcome measures were prostheses and implant failures, any complications, peri-implant marginal bone level changes and patient satisfaction. Patients were followed up to an average of 2.37 years after loading. RESULTS: 24 patients (5 Males and 19 Females; mean age: 60.5 year old) were enrolled in this study. They were treated with inlay technique, onlay technique, alveolar distraction osteogenesis and Guided Bone Regeneration (GBR). Complications were dehiscence/graft exposition, necrosis, periimplantitis, paresthesia, non integrated graft and graft infection; they occurred on average 6.5 weeks after surgery. Significantly more complications occurred in the GBR group than the onlay and the distraction group (Kruskal Wallis test; P = 0.001). 58 super short (4 mm) implants were placed in the posterior mandible after the resolution of the complications. Up to a mean period of 2.37 years after loading, only two patients experienced short implant and/or prosthesis failures. The resolution way of reconstructive complications did not influence the number of short implant complications. There were no statistically significant differences between marginal bone level changes at implant placement and at 1, 2, 3 years follow-up. The marginal bone level at 3 years follow-up was 0.62 mm. All patients were fully satisfied with the implant treatment. CONCLUSIONS AND CLINICAL IMPLICATIONS: This study suggests that super short (4 mm) dental implants could be a suitable, faster, cheaper and easier rehabilitation option in the failure of the reconstructive surgery of the atrophic posterior mandible. These results need to be confirmed by trials with follow-ups of at least 5 years.

BACKGROUND: To compare the outcome of preparation of zygomatic implant sites using a conventional preparation with rotary drills or piezosurgery for placing 2 zygomatic implants per zygoma according to a split-mouth design. METHODS: This study was performed at two centres. Each centre recruited 10 patients with atrophic fully edentulous maxilla not having sufficient bone volumes for placing dental implants. The patients had their right side of the mouth randomised to receive either 2 zygomatic implants following conventional site preparation with rotary instruments or piezosurgery. All implants had a diameter of 4.3 mm. Implants were immediately loaded with provisional prostheses which, 6 moths later, were replaced with definitive screw-retained prostheses. Patients were followed to 4 months post-loading and preliminary outcome measures were prosthesis and implant failures, complications, presence or absence of haematoma, time of site preparation. RESULTS: Ten patients were randomly allocated to each centre. One patient dropped out after surgery. Up to 4 months post-loading, 2 implants failed on the drill side while none of the implants failed on the other side (p= 0,317). One complication occurred on the piezo side while two complication occured on the drill side (p= 0,414). There were no statisti cally significant differences in prosthesis failures, implant failures and complications. Post operative haematoma looks larger at the drill side in 13 patients, it looks similar in extension at both side in 7 patients (p= 0,180). Tunnel preparation through piezoelectric inserts was 23.50±2.26 minutes while it was 14.35±1.76 minutes through traditional osteotomic rotary drills (p= 0,000). CONCLUSIONS: Zygomatic implants tunnel preparation with piezoelectric inserts and with drills produces comparable clinical results. Piezoelectric inserts allow for smaller haematoma at surgical sites even if with a longer preparation site.

BACKGROUND: Nowadays the majority of dental implants sold on the market are characterised by surfaces which have been roughened using different technologies, in order to increase the bone-to-implant contact area, with the aim of higher success rates, however there is not yet any reliable clinical evidence to substantiate this, although trends of early success rates are in favour of implants with roughened surfaces. On the contrary, data suggests that after 3 years in function, implants with a very rough surface have a 20% increased risk of being affected by peri-implantitis. The difficulties in the treatment of peri-implantitis and the uncertainty of the long-term prognosis of implants affected by peri-implantitis cast some doubts on the long-term outcome of implants, especially of implants with very roughened surfaces, making the use of implants with machined surfaces interesting once again, although with a more aggressive design aimed at achieving higher insertion torques. AIM/HYPOTHESIS: The aim of this randomised controlled trial of parallel group design was to compare the effectiveness of implant-supported total prostheses supported by four to eight immediately loaded dental implants with a rough surface versus implants with a machined/turned surface. The test hypothesis was that there were no differences between implants with machined and roughened surfaces against the alternative hypothesis of a difference. MATERIAL AND METHODS: Fifty edentulous or to-be-rendered edentulous patients requiring an implant-supported cross-arch prosthesis, were randomised either to receive four to eight implants (iRES SAGL, Lugano, Switzerland) with a roughened surface (25 patients) or with a machined/turned surface (25 patients). Provisional metal-reinforced acrylic prostheses were delivered 48 h after implant placement. Provisional prostheses were replaced after 4 months, by definitive screw-retained metal-resin cross-arch restorations. Outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone level changes. Patients were followed up to 1 year after loading. All data analysis was carried out according to a pre-established analysis plan. The patient was the statistical unit of the analyses. Differences in the proportion of patients with prosthesis failures, implant failures and complications were compared between groups using the Fisher’s exact probability test. Paired t-tests were used to compare the mean radiographic values at implant placement, and 1-year after loading. Sample t-tests were used to com- pare mean radiographic marginal bone level changes between groups. All statistical comparisons were conducted at the 0.05 level of significance. RESULTS: One year after loading no patient dropped out. No prosthesis failed, but two machined implants were found to be mobile at definitive impression taking in 1 patient (Fisher’s exact test: P = 0.312; difference in proportions = 4%; 95% Cl: 10 to 18). No complications occurred. Both groups presented a significant peri-implant marginal bone loss at 1 year after loading (P < 0.0001), 0.64 mm for rough implants and 0.68 mm for turned implants, respectively, with no statistically significant differences between the two groups (P = 0.482; mean difference = 0.04 mm; 95% Cl: 0.17 to 0.25). CONCLUSIONS AND CLINICAL IMPLICATIONS: Up to 1 year after immediate loading, both implant surfaces provided good and similar results, however, the only two implants which early failed in the same patient had a machined surface. However, these preliminary results must be confirmed by larger trials with longer follow-ups.

OBIETTIVO: Confrontare l’efficacia di impianti singoli post-estrattivi immediati con impianti dilazionati a 4 mesi posizionati in alveoli preservati. Gli impianti con un torque di inserimento di almeno 35 Ncm sono stati sottoposti a carico immediato non occlusale. MATERIALI E METODI: Immediatamente dopo l’estrazione dentale, e in presenza di meno di 4 mm di perdita di osso verticale buccale in relazione alla parete palatale, 106 pazienti che necessitavano di un impianto singolo post-estrattivo immediato nel mascellare superiore dal secondo al secondo premolare, sono stati randomizzati al gruppo degli impianti immediati (gruppo impianti immediati; 54 pazienti) o al gruppo sottoposto alla preservazione dell’alveolo mediante osso bovino anorganico coperto da barriera di collagene riassorbibile (gruppo impianti dilazionati; 52 pazienti), secondo uno studio a gruppi paralleli presso tre centri. Il protocollo prevedeva di riempire lo spazio osso-impianto con osso di bovino anorganico, tuttavia questo non è stato fatto per 17 dei pazienti (ovvero il 40% di coloro che avrebbero dovuto ricevere l’innesto). 4 mesi dopo la procedura di preservazione dell’alveolo, sono stati posizionati gli impianti dilazionati. Gli impianti con un torque di inserimento di almeno 35 Ncm sono stati caricati immediatamente con corone provvisorie singole non in occlusione, sostituite dopo 4 mesi con corone definitive. I pazienti sono stati seguiti per 1 anno dopo il carico. I parametri di valutazione presi in considerazione sono stati: fallimenti implantari, complicazioni, valutazione estetica realizzata mediante PES (pink esthetic score, punteggio di valutazione dell’estetica della gengiva), livelli ossei marginali peri-implantari e soddisfazione del paziente, registrati da valutatori in cieco. RISULTATI: 19 impianti (35%) non sono stati caricati immediatamente nel gruppo degli impianti immediati verso 39 (75%) nel gruppo a posizionamento dilazionato perché non era stato possibile raggiungere un torque superiore a 35 Ncm. Sei pazienti hanno lasciato lo studio dopo 4 mesi dal carico nel gruppo degli impianti dilazionati verso nessuno nel gruppo degli impianti immediati. Ci sono stati 2 fallimenti implantari nel gruppo degli impianti immediati (3,7%) verso nessuno nel gruppo dilazionato, ma la differenza non è statisticamente significativa (differenza delle proporzioni = 0,04; 95% IC da -0,03 a 0,11; P = 0,187). Si sono verificate 8 complicazioni minori nel gruppo degli impianti immediati e una nel gruppo degli impianti dilazionati e la differenza è statisticamente significativa (differenza delle proporzioni = 0,13; IC 95% da -0,03 a 0,23; P= 0,028). Alla consegna delle corone definitive, 4 mesi dopo il carico, la media del punteggio relativo all’estetica era di 12,8 e 12,6, rispettivamente nel gruppo degli impianti immediati e dilazionati. A 1 anno dal carico, la media del punteggio relativo all’estetica era di 13,0 e 12,8, rispettivamente per il gruppo degli impianti immediati e dilazionati. Le differenze a 4 mesi e a 1 anno non erano statisticamente significative, rispettivamente P = 0,500 e P = 0,615. I livelli ossei marginali all’inserimento degli impianti (dopo l’innesto osseo) erano di 0,10 mm per gli impianti immediati e 0,02 mm per gli impianti dilazionati, ma ciò non comporta una differenza staticamente significativa (differenza media = 0,08; IC 95%: da 0,04 a 0,12; P < 0,001). Un anno dopo il carico, i pazienti del gruppo degli impianti immediati hanno perso in media 0,23 mm verso 0,29 mm per quelli del gruppo degli impianti dilazionati, per una differenza statisticamente significativa (differenza media = -0,06; IC 95%: da -0,11 a -0,01; P = 0,036). I pazienti di entrambi i gruppi si sono dimostrati soddisfatti allo stesso modo,sia a 4 mesi che a 1anno dal carico. CONCLUSIONI: Si riscontra un maggior numero di complicazioni per gli impianti post-estrattivi immediati rispetto a quelli dilazionati. Sembra che sia più difficile ottenere un torque di inserimento superiore a 35 Ncm negli alveoli preservati con osso bovino anorganico dopo 4 mesi di guarigione rispetto ai siti post-estrattivi. Il risultato estetico è simile per entrambi i gruppi.

BACKGROUND: In many clinical situations it is not possible to place dental implants of ‘adequate length’ because there is less than 8 mm of residual vertical bone height. Clinicians are faced with the dilemma of whether to augment the bone or to place short implants having an intrabony length of 8 mm or less. Augmentation procedures are more technically demanding and therefore require skilful operators, as they can be associated with significant postoperative morbidity and complications, and can be more expensive and may require longer times. Short implants could be a simpler, cheaper and faster alternative if they could provide similar clinical outcomes to longer implants placed in augmented bone. AIM/HYPOTHESIS: To evaluate whether 5-mm short dental implants could be an alternative to augmentation with anorganic bovine bone and placement of at least 10-mm long implants in posterior atrophic jaws. MATERIAL AND METHODS: Fifteen patients with bilateral atrophic mandibles (5–7 mm bone height above the mandibular canal) and 15 patients with bilateral atrophic maxillae (4–6 mm bone height below the maxillary sinus), and bone thickness of at least 8 mm, were randomised according to a split-mouth design to receive one to three 5-mm short implants or at least 10-mm long implants (MegaGen Implant, Gyeongbuk, South Korea) in augmented bone. Mandibles were vertically augmented with interpositional bone blocks and maxillary sinuses with particulated bone via a lateral window. Implants were placed after 4 months, submerged and loaded, after another 4 months, with provisional prostheses. Four months later, definitive provisionally cemented prostheses were delivered. Outcome measures were: prosthesis and implant failures; any complication and peri-implant marginal bone level changes. RESULTS: Three years after loading 2 patients dropped out. Three prostheses failed in the short implant group vs. none in the long implant group. In mandibles, 1 long implant failed vs. 2 short implants in 1 patient. In maxillae, 1 long implant failed vs. 3 short implants in 2 patients. There were no statistically significant differences in the failures. Eight patients had 13 complications at short implants and 11 patients had 13 complications at long implants. There were no statistically significant differences in complications (P = 0.63, difference = 0.10, 95% CI from 0.22 to 0.42). Three years after loading in patients with mandibular implants the difference in terms of peri-implant marginal bone loss was not statistically significant (difference = 0.24 mm; 95% CI 0.01, 0.49 P = 0.059). In maxillae, patients lost on average 1.02 mm at short implants and 1.54 mm at long implants. This difference was statistically significant (difference = 0.41 mm; 95% CI 0.21, 0.60, P = 0.001). CONCLUSIONS AND CLINICAL IMPLICATIONS: Three years after loading, 5-mm short implants achieved similar results as longer implants in augmented bone. Short implants might be a preferable choice to vertical bone augmentation, especially in mandibles, since the treatment is faster and cheaper, however there are still insufficient data on the long-term prognosis of short implants.

BACKGROUND: While it has been shown that it is possible to vertically augment bone with different procedures, these techniques are associated with significant postoperative morbidity and complications, can be expensive and technique sensitive, and require long treatment periods. Short implants could be a simpler, cheaper and faster alternative to vertical bone augmentation, if they will provide similar success rates. While it is common sense to use longer implants when bone heights allow it, it remains unclear how to proceed in the presence of residual mandibular bone height ranging from between 5 mm to 8 mm. AIM/HYPOTHESIS: To evaluate whether 6.6 mm long implants could be a suitable alternative to longer implants placed in vertically augmented atrophic posterior mandibles. MATERIAL AND METHODS: Sixty partially edentulous patients having 7 to 8 mm of residual crestal height and at least 5.5 mm thickness measured on CT scans above the mandibular canal were randomised according to a parallel group design. They were either to receive 1 to 3 submerged 6.6-mm long implants (Nanotite, External Hex, Biomet 3i, Palm Beach, FL, USA) or 9.6 mm or longer implants of the same type (30 patients per group) placed in vertically augmented bone. Bone was augmented with interpositional anorganic bovine bone blocks covered by resorbable barriers. Grafts were left to heal for 5 months before implant placement. Four months after provisional acrylic prostheses were delivered, they were replaced, after 4 months, by definitive metal-ceramic prostheses. Outcome measures were: prosthesis and implant failures; complications; and radiographic peri-implant marginal bone level changes. All patients were followed up to 5 years after loading. RESULTS: Five years after loading, eight patients dropped out. The augmentation procedure failed in two patients. There were no statistically significant differences for prosthesis and implant failures. Five prostheses failed in four patients of the short implant group vs. five prostheses in five patients in the augmented group (Fishers exact test P = 1.0; difference in proportions = 0.07; 95% CI 0.29 to 0.43). Five short implants failed in three patients vs. three long implants in three patients (Fishers exact test P = 1.00 difference in proportions = 0.00; 95% CI 0.43 to 0.43). There were statistically more complications in augmented patients (25 complications in 21 augmented patients vs. six complications in six patients of the short implant group) (Fishers exact test P < 0.0001; difference in proportions = 0.60; 95% CI 0.38, 0.82). Five years after loading short implants experienced statistically significantly less bone loss (0.82 mm, 95% CI 0.48; 1.16, P < 0.0001) than long implants. CONCLUSIONS AND CLINICAL IMPLICATIONS: When residual bone height over the mandibular canal is between 7 to 8 mm, 6.6 mm short implants could be an interesting alternative to vertical augmentation in posterior atrophic mandibles since the treatment is faster, cheaper and associated with less morbidity. Longer follow-ups may still be needed to confirm these results, however the medium-term prognosis (5 years after loading) of short implants is at least as good as those of longer implants placed vertically in augmented mandibles.

AIM: We describe a successful implant-prosthetic rehabilitation of an atrophic posterior mandible with 4 mm long implants. MATERIAL AND METHODS: The patient refused to undergo any reconstructive surgery and, because the available bone up to the inferior alveolar nerve was only 4.5 and 5 mm, the patient received 4 implants of 4 mm length. RESULTS: Four months after implant positioning, a temporary prosthesis was put in place which was then replaced by a permanent prosthesis after another four months. The follow-up time is at three years after implants loading. CONCLUSION: With the limits of this case report the use of such short implants can allow a fixed prosthetic solution without the need for vertically augmenting of the mandibular bone. This procedure considerably reduces intra and postoperative patient discomfort compared to reconstructive surgery for the placing of longer implants.

BACKGROUND: Short dental implants are used as an alternative to longer implants in purposely augmented bone to support fixed prostheses in the rehabilitation of patients with atrophic jaws. There are a few randomised controlled trials (RCTs) comparing the effectiveness of dental prostheses supported by short implants with those supported by longer implants placed in augmented bone. Results of these ongoing trials having follow-ups up to 5-year post-loading, suggest that 5 to 8 mm long implants can be a viable, if not a better, alternative to augmentation procedures, especially in posterior mandibles. More recent clinical questions are whether to use short implants also in those situation were longer implants could have been used and how short could be an implant still able to provide a good long-term outcome. AIM/HYPOTHESIS: To evaluate whether 4x4 mm dental implants could be an alternative to implants at least 8.5 mm long placed in posterior jaws in the presence of adequate bone volumes. MATERIAL AND METHODS: One-hundred-fifty patients with posterior (premolar and molar areas) mandibles having at least 12.5 mm bone height above the mandibular canal or 11.5 mm below the maxillary sinus, were randomised according to a parallel group design to receive one to three 4 mm long implants or one to three at least 8.5 mm long implants at 3 centres. All implants (TwinKon Universal SA2, Global D, Lyon, France) had a diameter of 4 mm. Implants were loaded after 4 months with definitive screw-retained prostheses. Patients were followed to 4-month post-loading and outcome measures were: prosthesis and implant failures, any complication and peri-implant marginal bone level changes. All data analysis was carried out according to a pre-established analysis plan. A biostatistician with expertise in dentistry analysed the data, without knowing the group codes. The patient was the statistical unit of the analyses. All statistical comparisons were conducted at the 0.05 level of significance. Results: No patients dropped-out. Three patients experienced the early failures of one 4 mm short implant each vs. two patients who lost one long implant each (difference in proportion = 1; CI 95% 0.034 to 7.2; P = 0.50). Consequently, two prostheses in each group could not be delivered as planned (difference in proportion = 0; CI 95% 0 to 4.8; P = 0.69), and one patient from each group is still waiting to have their prostheses delivered. Three short implant patients experienced three complications vs. two long implant patients (difference in proportion = 1; CI 95% 0.034 to 7.2; P = 0.50). There were no statistically significant differences in prosthesis failures, implant failures and complications. Patients with short implants lost on average 0.378 mm of peri-implant bone at 4-month and patients with longer mandibular implants lost 0.416 mm. There were not statistically significant differences in bone level changes up to 4-month (mean difference 0.038 mm, 95% CI 0.118 to 0.041; P = 0.274). CONCLUSIONS AND CLINICAL IMPLICATIONS: Four-month after loading 4x4 mm implants achieved similar results as 8.5x4 mm long or longer implants in posterior jaws, however 5 to 10 years post-loading data are necessary before making reliable recommendations.

OBJECTIVES: To evaluate whether 6.6-mm long implants could be a suitable alternative to longer implants placed in vertically augmented atrophic posterior mandibles. MATERIALS AND METHODS: Sixty partially edentulous patients having 7 to 8 mm of residual crestal height and at least 5.5 mm thickness measured on CT scans above the mandibular canal were randomised according to a parallel group design. They were either to receive 1 to 3 submerged 6.6-mm long implants or 9.6 mm or longer implants (30 patients per group) placed in vertically augmented bone. Bone was augmented with interpositional anorganic bovine bone blocks covered by resorbable barriers. Grafts were left to heal for 5 months before implant placement. Four months after provisional acrylic prostheses were delivered, they were replaced, after 4 months, by definitive metal-ceramic prostheses. Outcome measures were: prosthesis and implant failures; complications; and radiographic peri-implant marginal bone level changes. All patients were followed up to 5 years after loading. RESULTS: Five years after loading, 8 patients dropped out: 3 from the short implant group and 5 from the augmented group. The augmentation procedure failed in 2 patients and only 6.6-mm long implants could be inserted. There were no statistically significant differences for prosthesis and implant failures. Five prostheses failed in 4 patients of the short implant group versus 5 prostheses in 5 patients in the augmented group (Fishers exact test P = 1.0; difference in proportions = 0.07; 95% CI -0.29 to 0.43). Five short implants failed in 3 patients versus 3 long implants in 3 patients (Fishers exact test P = 1.00 difference in proportions = 0.00; 95% CI -0.43 to 0.43). There were statistically more complications in augmented patients (25 complications in 21 augmented patients versus 6 complications in 6 patients of the short implant group) (Fishers exact test P < 0.0001; difference in proportions = 0.60; 95% CI 0.38, 0.82). Both groups gradually lost peri-implant bone in a statistically significant way. Five years after loading, short implant group patients lost an average of 1.49 mm peri-implant bone compared with 2.34 mm in the augmented group. Short implants experienced statistically significantly less bone loss (0.82 mm, 95% CI 0.48; 1.16, P < 0.0001) than long implants. CONCLUSIONS: When residual bone height over the mandibular canal is between 7 to 8 mm, 6.6 mm short implants could be an interesting alternative to vertical augmentation in posterior atrophic mandibles since the treatment is faster, cheaper and associated with less morbidity. Longer follow-ups may still be needed to confirm these results, however the medium-term prognosis (5 years after loading) of short implants is at least as good as those of longer implants placed vertically in augmented mandibles. Conflict of interest statement: Biomet 3i, manufacturer of the implants used in this investigation, partially supported this trial. However data properties belonged to the authors and by no means did Biomet 3i interfere with the conduct of the trial or the publication of the results.

Purpose: A novel technique to perform safe osteotomies during inlay block regenerative procedures in the posterior atrophic mandible is described. Material and Methods: A 52-year-old male patient with vertical atrophy of the left posterior mandible was treated adopting an inlay block “sandwich” technique using an allogenic cancelous block and a mixture of mineralized and demineralized human bone allograft in putty form as graft. The horizontal osteotomy for the lifting of the osteotomized bone segment was performed using a template prepared from a virtual anatomical replica of the patient's mandible obtained from cone beam computed tomography data. In the second surgical phase, 3 months after the augmentation, 2 implants were easily placed. Results: The horizontal osteotomy was carried out, with no risk, very close to the nerve structures after the precise osteotomy line established preoperatively on the three-dimensional computed tomography (3D-CT) virtual reconstruction. No neurological complications were observed in the first days after the procedure, and no subsequent problems were recorded during the 3-month healing period. Conclusion: Radiographic evaluations and complication-free clinical healing demonstrate the effectiveness of this technique to obtain safe and precise osteotomies.

PURPOSE: To compare the efficacy of 1-stage versus 2-stage lateral maxillary sinus lift procedures. MATERIALS AND METHODS: Sixty partially edentulous patients requiring 1 to 3 implants and having 1 to 3 mm of residual bone height and at least 5 mm bone width below the maxillary sinus, as measured on CT scans were selected. They were randomised according to a parallel group study design into two equal arms to receive either a 1-stage lateral window sinus lift with simultaneous implant placement or a 2-stage procedure with implant placement delayed by 4 months, using a bone substitute in three different centres. Implants were submerged for 4 months, loaded with reinforced provisional prostheses, which were replaced, after 4 months, by definitive prostheses. Outcome measures, assessed by masked assessors, were: augmentation procedure failures; prosthesis failures and implant failures; complications; and marginal peri-implant bone level changes. Patients were followed up to 1 year after loading. Only data of implants placed in 1 to 3 mm of bone height were reported. RESULTS: Two patients dropped out from the 1-stage group and none from the 2-stage group. No sinus lift procedure failed in the 1-stage group but one failed in the 2-stage group, the difference being not statistically significant (P = 1.00). Two prostheses failed or could not be placed in the planned time in the 1-stage group and one in the 2-stage group, the difference being not statistically significant (P = 0.51). Three implants failed in three patients of the 1-stage group, versus one implant in the 2-stage group, the difference being not statistically significant (P = 0.28). Two complications occurred in the 1-stage group and one in the 2-stage group, the difference being not statistically significant (P = 0.61). One year after loading, 1-stage treated patients lost an average of -1.01 mm (SD: 0.56) of peri-implant bone and 2-stage sites about -0.93 mm (SD: 0.40). There were no statistically significant differences in bone level change between groups 1 year after loading (-0.08 mm 95%CI: -0.33 to 0.18 P = 0.56). CONCLUSION: No statistically significant differences were observed between implants placed according to 1- or 2-stage sinus lift procedures. However this study may suggest that in patients having residual bone height between 1 to 3 mm below the maxillary sinus, there might be a slightly higher risk for implant failures when performing a 1-stage lateral sinus lift procedure.

Purpose A new augmentation procedure for bone reconstruction of horizontal defects in a posterior atrophic mandible is described. Materials and methods A 47-year-old male patient with horizontal atrophy of the left posterior mandible was treated using a 2-stage modified "sandwich" osteotomy technique with an interposed mixture of mineralized and demineralized human bone allograft in putty form. Results The osteotomized superior segment was slightly raised and then drawn and rotated in the buccal direction to augment the horizontal width of the crest. The osteotomized segment was kept in this position with a titanium miniplate and miniscrews. No complications were reported during the 3-month healing period. In the second surgical phase, 2 implants were correctly placed. Conclusions Cone beam computed tomography (CBCT) outcomes confirm the effectiveness of this technique in the treatment of horizontal defects. However, further randomized controlled studies are required to confirm the technique's reliability.