PURPOSE To evaluate the clinical outcome of four to five implants immediately restored with metal-resin screw-retained cross-arch fixed prostheses in edentulous jaws 1 year after loading. MATERIALS AND METHODS In total, 104 consecutive patients received four 11 × 4.5 mm implants with a torque superior to 35 Ncm. If one implant did not reach a torque superior to 35 Ncm a fifth implant was added. If two implants did not reach a torque superior to 35 Ncm, loading was postponed after 3 months. A total of 127 metal-resin screw-retained fixed prostheses (59 mandibular and 68 maxillary) were to be delivered within 3 days. Outcome measures, evaluated by the treating clinician, were: prosthesis and implant failures, as well as complications. RESULTS In total, 549 implants were placed (195 immediate post-extractive implants). Twelve maxillary prostheses were delayed loaded, whereas all others were loaded immediately. One year after loading, six patients dropped out, 12 implants failed in eight patients (two patients lost three implants each), and 87 prostheses were remade in 68 patients, one because of three implant failures and then again in the recall programme (replaced twice), one because of tree implant failures and five prosthesis fractures, 10 because of prostheses fractures and 74 in a recall programme for prosthesis replacement. All patients were wearing the planned fixed prostheses at the end of the first year in function. Ninety-eight complications occurred in 66 patients, but all were successfully solved. CONCLUSIONS Immediately loaded cross-arch prostheses supported by four to five implants are a viable therapeutic option, if prostheses are made with resistant frameworks.
Purpose: To evaluate possible risk factors associated with wound dehiscences following pre-implant alveolar bone augmentation with autologous anterior iliac crest bone grafts covered with resorbable collagen membranes or human demineralised bone laminae. Materials and methods: Data of 161 patients who underwent bone augmentation prior to the insertion of dental implants were analysed. The preoperative dental status, locations of alveolar bone augmentation sites and location of wound dehiscences were recorded. Gender, age, smoking, alcohol exposure, and dental and medical histories were reviewed. Information was also collected on the surgeons, augmentation technique, application of a collagen membrane, fixation screw type and suture material. Univariate logistic regression analysis was used to evaluate pre- and perioperative variables as predictors of dehiscences. Results: A total of 42 (26.1%) of the 161 augmented patients developed a wound dehiscence following surgery. Most commonly affected sites were the anterior maxilla, followed by the anterior mandible. Males developed wound dehiscences with higher probability than females (odds ratio female = 0.444; P = 0.025; 95% CI: 0.214 to 0.903). Furthermore, marginal associations (P < 0.10) are found for smoking and an anterior location of the augmentation. Smokers were found to have higher probability of a wound dehiscence (odds ratio 2.089; P = 0.064; 95% CI: 0.957 to 4.500) compared to non-smokers. A posterior location of the augmentation was associated with lower probability of a wound dehiscence (odds ratio 0.188; P = 0.076; 95% CI: 0.035 to 0.802) compared to an anterior location. Conclusions: Based on this study population, smoking in males seems to be the most important risk factor for the development of wound dehiscences after pre-implant alveolar bone augmentation procedures.
PURPOSE To evaluate whether 5.0 × 5.0 mm dental implants with a novel nanostructured calcium-incorporated titanium surface could be an alternative to implants of at least 10.0 mm long placed in bone augmented with bone substitutes in posterior atrophic jaws. MATERIALS AND METHODS Forty patients with atrophic posterior (premolar and molar areas) mandibles with 5.0 mm to 7.0 mm bone height above the mandibular canal, and 40 patients with atrophic maxillas with 4.0 mm to 6.0 mm below the maxillary sinus, were randomised according to a parallel group design to receive between one and three 5.0 mm implants or one to three at least 10.0 mm-long implants in augmented bone at two centres. All implants had a diameter of 5.0 mm. Mandibles were vertically augmented with interpositional bovine bone blocks covered with 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 cement metal-ceramic or zirconia prostheses were delivered. Patients were followed to 3 years post-loading and the outcome measures were: prosthesis and implant failures, any complication, and peri-implant marginal bone level changes. RESULTS Seven patients dropped out before the 3-year evaluation (two short mandibles, one short maxilla, two augmented mandibles and two augmented maxillae). In mandibles, two grafted patients were not prosthetically rehabilitated because of multiple complications and two implants failed in the same patient (the second was a replacement implant) vs one patient who lost a short implant and crown 2 years after loading. In maxillas one short implant failed with its provisional crown 3 months post-loading. There were no statistically significant differences in prostheses (difference in proportion = 0.001; 95% CI: -0.12 to 0.13; P = 1.000) and implant failures (difference in proportion = 0.00; 95% CI: -0.13 to 0.13; P = 1.000) up to 3 years after loading. Significantly, more complications occurred at mandibular grafted sites: 17 augmented patients were affected by complications vs eight patients treated with short implants in mandibles (difference in proportion = 0.43; 95% CI: 0.13 to 0.64; P = 0.008). In the maxilla, six sinus-lifted patients vs two patients treated with short implants were affected by complications; the difference not being statistically significant (difference in proportion = 0.21; 95% CI: -0.05 to 0.45; P = 0.232). Patients with mandibular short implants lost on average 1.10 mm of peri-implant bone at 3 years and patients with 10.0 mm or longer mandibular implants lost 1.39 mm. Patients with maxillary short implants lost on average 1.04 mm of peri-implant bone at 3 years and patients with 10 mm or longer maxillary implants lost 1.43 mm. Longer implants showed a greater bone loss up to 3 years after loading than short implants both in maxillae (mean difference: -0.39 mm; 95% CI: -0.70 to -0.07 mm; P = 0.017) and in mandibles (mean difference: -0.29 mm; 95% CI: -0.53 to -0.05 mm; P = 0.020). CONCLUSIONS Three years after loading, 5.0 mm × 5.0 mm implants achieved similar 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, 5- to 10-year post-loading data are necessary before making reliable recommendations.
PURPOSE:The aim of this study was to compare survival and success rates of 6 mm-long and 10 mm-long implants in partially edentulous posterior areas.MATERIALS AND METHODS:Twenty-four patients with a partially edentulous area were included in the study. Patients were randomly allocated according to a parallel group design to receive 6 mm or 10 mm-long implants. A total of 54 implants were placed (26 × 6 mm implants). Patients were followed for 10 years after prosthetic loading. Outcome measures were prosthesis and implant survival, marginal bone level changes and complications.RESULTS:After 10 years, 17 patients (eight with 6 mm implants and nine with 10 mm implants) were available: three 6 mm and four 10 mm patients were lost to follow-up. One 6 mm implant failed during the healing period and its related prosthesis could not be placed. No implants were lost after loading. Nine patients in the 6 mm group registered a total of 15 complications: two mucositis, six decementations and seven chippings. Ten patients in the 10 mm group registered a total of 13 complications: five mucositis, two decementations and six chippings. Overall the difference for complications between the two groups was not statistically significant (P = 0.22; difference in proportion = -0.02; 95% CI: -0.31 to 0.27). Decementations in the 6 mm group were statistically significant higher than the 10 mm group (P = 0.04; difference in proportion = 0.39; 95% CI: 0.03 to 0.74). Marginal bone loss at 10 years was 0.84 and 0.37 mm with the 6 mm and 10 mm groups, respectively (difference between the two groups 0.49 mm; 95% CI -0.31; 1.29; not statistically significant: t test P = 0.22).CONCLUSIONS:Rehabilitations supported by 6 mm or 10 mm-long implants showed similar clinical outcomes in terms of survival and success rates, although 6 mm implants had more decementations.
Semantics is a term coined by Michel Breal (1832 to 1915) a Jewish German-French linguist referring to the Greek semantikos (= meaning) in his 1897 book, "Essai de semantique". He was a very gifted man: for example, he was the one who suggested to Pierre de Coubertin to include the marathon in the Olympic Games and who also, with the help of a Francophile American dental practitioner, Thomas William Evans, created the "Doctorat d'Universite", finally allowing American students to pursue their doctorate at a French university.
PURPOSE:To evaluate the effect of sub-mucosal mechanical instrumentation following supra-mucosal plaque removal in the treatment of peri-implant mucositis.MATERIALS AND METHODS:A total of 44 patients, 27 from a specialist clinic in Sweden, and 17 from a Japanese one, were included. The 44 patients had a total of 175 implants of which 84 (48%) had clinical signs of mucositis (bleeding on probing [BoP]) and no radiographic bone loss. At baseline, the 44 patients received professional supra-mucosal plaque removal and oral hygiene instruction and motivation. Following the 1-month examination, sub-mucosal instrumentation was initiated using ultrasonic and hand instruments. Patients were then examined at 4 and 7 months. Presence of plaque, marginal bleeding, BoP and probing pocket depth (PPD) changes were recorded at each examination in an unblinded manner.RESULTS:One month following supra-mucosal plaque removal, the number of treated implants with BoP was reduced from 84 to 44 (48% reduction) with a concomitant decrease of the mean PPD of 0.6 mm (95% CI: -0.5 to -0.7), from 4.4 ± 1.0 mm (mean ± SD) to 3.8 ± 1.0 mm, P < 0.0001. Following sub-mucosal instrumentation, a further reduction of 9% (from 44% to 36%) of BoP was recorded, with a concomitant reduction of the mean PPD of 0.3 mm (95% CI: -0.1 to -0.4) at the 7-month examination.CONCLUSIONS:The improvement of the clinical condition (absence of marginal bleeding, BoP and PPD reduction at treated implants) following non-surgical treatment of mucositis appeared to be in great part because of supra-mucosal plaque removal, while the sub-mucosal instrumentation seemed to have only a minor additional effect. Deep implant position compared to neighbouring teeth/implant was associated with persisting mucositis following treatment. The presence of deep pockets following treatment was associated with BoP, screw-retained prostheses without abutment and sub-mucosal crown margins.
PURPOSE 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 computed tomography scans above the mandibular canal were randomly allocated according to a parallel-group design either to receive one to three 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 fixed with titanium plates and covered with resorbable barriers. Grafts were left to heal for 5 months before implant placement. Four months after implant placement, provisional acrylic prostheses were delivered, 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. Patients were followed up to 8 years after loading. RESULTS Eight years after loading 12 patients dropped out, five from the short implant group and seven from the augmented group. The augmentation procedure failed in two patients and only 6.6-mm long implants could be inserted. There were no statistically significant differences for prosthesis and implant failures. Four prostheses failed in three patients of the short implant group versus three prostheses in three patients of the augmented group (Fisher exact test P = 1.000; difference in proportions = 0.01; 95% CI: -0.19 to 0.22). Five short implants failed in three patients versus three long implants in three patients (Fisher exact test P = 1.000; difference in proportions = 0.01; 95% CI: -0.19 to 0.22). There were statistically more complications in augmented patients (27 complications in 22 augmented patients versus 9 complications in 8 patients of the short implant group) (Fisher exact test P < 0.001; difference in proportions = 0.64; 95% CI: 0.38 to 0.79). Both groups gradually lost peri-implant bone in a statistically significant way. Eight years after loading, short implant group patients lost an average of 1.58 mm of peri-implant bone compared with 2.46 mm in the augmented group. Short implants experienced statistically significantly less bone loss (0.88 mm, 95% CI: 0.50 to 1.26 mm) than long implants. CONCLUSIONS When residual bone height over the mandibular canal is between 7 and 8 mm, 6.6-mm short implants are an interesting alternative to vertical augmentation in posterior atrophic mandibles since the treatment is faster, cheaper and associated with less morbidity.
Purpose: To ascertain whether in the presence of a previously endodontically treated tooth with periapical pathology and/or symptoms and an uncertain prognosis, it is better to endodontically retreat it or to replace the tooth with a single-implant-supported crown. Materials and methods: Twenty patients requiring the treatment of a previously endodontically treated tooth, with periapical pathology and/or symptoms of endodontic origin and an uncertain prognosis, as judged by the recruiting investigator, were randomly allocated to endodontic retreatment (Endo group, 10 patients) or tooth extraction and replacement with an implant-supported crown (Implant group, 10 patients) according to a parallel-group design at a single centre. Patients were followed to 3 years after completion of the treatment. Outcome measures were: failure of the procedure, complications, marginal bone level changes at both teeth and implants, endodontic radio-graphic success (teeth only), number of patients' visits and days to complete the treatment, patients' chair time, costs, aesthetics assessed using the pink aesthetic score (PES) for the soft tissues and the white aesthetic score (WES) for the tooth/crown recorded by independent assessors. Results: No patient dropped out. One endodontically retreated tooth fractured and another had a crown loosening. There were no statistically significant differences for treatment failure or complications (difference in proportions = 0.10; 95% CI: -0.09 to 0.29; P (Fisher exact test) = 1.000). The mean marginal bone levels at endodontic retreatment/implant insertion were 2.10 +/- 0.66 mm for the Endo group and 0.05 +/- 0.15 mm for the Implant group. Three years after completion of the treatment, teeth lost on average 0.23 +/- 0.82 mm and implants 0.62 +/- 0.68 mm, the difference not being statistically significant (mean difference = -0.39 mm; 95% confidence interval [CI]: -1.12 to 0.33; P (t test) = 0.267). Three years after completion of the endodontic retreatment, of the four teeth that originally had a periapical radiolucency, one was lost, two showed complete healing, and one showed radiographic improvement. There were no statistically significant differences for the number of patients' visits (Endo = 6.67 +/- 0.71; Implant = 6.10 +/- 0.74; mean difference = 0.57; 95% CI: -0.14 to 1.27; P (t test) = 0.106). It took significantly more days to complete the implant rehabilitation (Endo = 61 +/- 12.97; Implant = 191.40 +/- 75.04; mean difference = -130.40; 95% CI: -184.45 to -76.35; P (t test) < 0.001) but less patients' chair time (Endo = 629.44 +/- 43.62 min; Implant = 326 +/- 196.99 min; mean difference = 303.44; 95% CI: 160.87 to 446.02; P (t test) = 0.001). Implant treatment was significantly more expensive (Endo = (sic)1,588.89 +/- 300.81; Implant = (sic)2,095 +/- 158.90; mean difference = (sic)-506.11; 95% CI: -735.41 to -276.82; P (t test) <0.001). Three years after treatment completion, mean PES were 11.11 +/- 1.97 and 6.50 +/- 2.46 and mean WES were 7.78 +/- 1.30 and 6.80 +/- 2.39 in the Endo group and Implant group, respectively. Soft tissues aesthetics (PES) were significantly better at endodontically retreated teeth (mean difference 4.61; 95% CI: 2.44 to 6.78; P (t test) < 0.001) whereas no significant differences were observed for tooth aesthetics (WES) (mean difference 0.98; 95% CI: -0.89 2.85; P (t test) = 0.281) between treatments. Conclusions: The present preliminary results suggest that both endodontic retreatment and replacement of previously endodontically treated teeth with persisting pathology and a dubious endodontic prognosis provided similar short-term success rates. Aesthetics of the soft tissues and time needed to complete treatment were in favour of endodontic retreatment whereas implant rehabilitation required half of the chair time than endodontic retreatment, but was significantly more expensive. Much larger patient populations and longer follow-ups are needed to fully answer this question; however, in this scenario the less invasive endodontic retreatment could be the first therapeutic option to be considered.
The aim of this histologic, double-blind, parallel, randomized controlled trial was to compare anorganic bone mineral-collagen membranes (BB) and beta-tricalcium phosphate-pericardium collagen membranes (CJ) in a one-stage procedure for horizontal bone augmentation. A biopsy was performed in the regenerated area at abutment connection 6 months after surgery. Five patients were assigned and treated with the BB combination and five patients were treated with the CJ combination. At abutment connection, 6 months after grafting, no significant differences were evident in the histomorphometric comparisons, even if the percentage of residual graft, using the marrow spaces and soft tissue as a reference, tended to be greater in the CJ group (P = .0759).
PURPOSE To present a rare clinical case of migration of a displaced implant fragment from the maxillary sinus to the stomach. MATERIALS AND METHODS A 66-year-old man was referred from a local dental clinic to remove a displaced implant apical fragment in the left maxillary sinus. After 15 days from the displacement, no foreign body was seen in the maxillary sinus or in any other craniofacial cavity. Thoracic and abdominal radiographs were taken, and a 3 × 3 mm radiopaque object, which corresponded to the piece of implant fragment, was detected within the patient's stomach. RESULTS Follow-up radiographs were taken to monitor the progress after 1 week, and it was found that the radiopaque object had disappeared. CONCLUSIONS A displaced dental implant fragment in the maxillary sinus can migrate and exit from the maxillary sinus within a few days. Since it presents a potential risk for swallowing or aspiration, displaced implants or other objects in the maxillary sinus should be removed immediately. Before removal, additional radiographs are recommended to confirm the current position of the implant.
PURPOSE To compare the clinical outcome (in particular of marginal peri-implant bone level changes) between immediately loaded straight implants which had definitive abutments placed at implant placement and never removed versus implants which had no intermediate abutments. MATERIALS AND METHODS Thirty-two edentulous patients had one of their jaws rehabilitated with a provisional screw-retained resin reinforced cross-arch fixed prosthesis supported by four immediately loaded implants: two central straight implants and two either tilted or straight distal implants. The two central straight implants were randomly allocated in two equal groups to receive or not an intermediate abutment (Multi-Unit Abutment, MUA) according to a parallel group design. To be immediately loaded implants had to be inserted with a minimum torque of 30 Ncm, which was achieved by all implants. After 4 months, definitive screw-retained metal-ceramic prostheses were delivered and patients were followed-up to 5 years after loading. Prostheses were removed every 8 months to facilitate professionally delivered maintenance. Outcome measures were prosthesis and implant failures, complications, peri-implant marginal bone level changes and bleeding on probing (BoP). RESULTS Five-years after loading one patient dropped out from each group. No implant or prosthetic failure occurred. Three patients of the abutment group versus one of the no-abutment group were affected by complications (risk difference = 0.125; 95% CI: -0.13 to 0.37; Fisher exact test, P = 0.600). At 5 years, both groups lost marginal bone in a statistically significant way (0.32 ± 0.40 mm for patients of the abutment group and 0.35 ± 0.29 mm for patients of the no-abutment group), with no difference in bone loss between groups at patient levels (difference = 0.03 mm; 95% CI: -0.23 to 0.29 mm; P = 0.809). At 5 years, BoP was significantly higher in the no-abutment group than in the abutment group (difference between medians = 25%; 95% CI: 12.5% to 25%; P < 0.001). By considering only the average of the two central study implants per patient with and without intermediate abutments, there were no differences in bone loss (difference: -0.05 mm; 95% CI: -0.41 to 0.31 mm; P = 0.763), while marginal bleeding was significantly higher in the no-abutment group (difference between medians = 25%; 95% CI: 0% to 50%; P = 0.004). CONCLUSIONS The present results suggest that intermediate abutments may not be needed at immediately loaded cross-arch screw-retained prostheses, unless there is the necessity to correct implant angulation.
PURPOSE:To compare outcomes of immediate non-occlusal loading with delayed implant loading in the bilateral replacement of mandibular first molars.MATERIALS AND METHODS:This study was designed as a split-mouth, randomised controlled trial. Twenty patients with bilaterally missing mandibular first molars randomly received immediately or conventionally loaded single implants. One molar was restored with a non-occlusal temporary crown within 24 hours after implant placement (immediate loading group, IL) while the contralateral molar was restored with a definitive crown 4 to 5 months later (delayed loading group, DL). A total of 40 implants were installed. All implants were inserted in healed bone with an insertion torque between 35 and 45 Ncm. Outcome measures were implant failure, complications, radiographic marginal bone level changes, probing pocket depths (PPDs) and bleeding on probing (BOP). Clinical data were collected at implant placement, and after 6, 12 and 60 months.RESULTS:No patients dropped out and no implant failed. Only minor prosthetic complications were observed (two provisional acrylic crown fractures in the IL group and four ceramic chipping in the DL group). Two patients had bilateral peri-implant mucosal inflammation with BOP after 6 months. The differences between groups were not statistically significant (OR = 0.500; 95% CI: 0.045 to 3.489; P = 0.6831). At the 1-year follow-up examination, the mean marginal bone level was 0.83 ± 0.16 mm (95% CI: 0.75 to 0.91) in the IL group and 0.86 ± 0.16 mm (95% CI: 0.78 to 0.94) in the DL group, with no statistically significant differences between groups (difference = 0.03 ± 0.15 mm; 95% CI: -0.07 to 0.07; P = 0.53). After 5 years, mean marginal bone level was 1.06 ± 0.38 mm (95% CI: 0.97 to 1.15) in the IL group and 1.07 ± 0.32 mm (95% CI: 0.95 to 1.16) in the DL group, with no statistically significant differences between groups (difference = 0.01 ± 0.22 mm; 95% CI: -0.10 to 0.10; P = 0.96). The mean marginal bone loss after 5 years was 0.62 ± 0.45 mm in the IL group and 0.69 ± 0.33 mm in the DL group (difference = 0.07 ± 0.32 mm; 95% CI: -0.10 to 0.18; P = 0.567). At the 5-year follow-up the mean PPD and BOP values were 2.82 ± 0.65 mm and 1.17 ± 0.92 in the IL group, and 2.85 ± 0.53 mm and 1.17 ± 0.86 in the DL group, respectively. No significant differences were found (difference = 0.03 ± 0.15 mm; 95% CI: -0.15 to 0.21; P = 0.990; and 0.01 ± 0.07; 95% CI: -0.06 to 0.08; P = 1.000, respectively).CONCLUSIONS:Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of immediate versus delayed loading of implants in mandibular fist molar sites is comparable.
PURPOSE:To compare the outcome of cross-arch prostheses supported either by 5 mm long or 11.5 mm long implants placed flapless and immediately restored with a metal-resin screw-retained cross-arch prostheses. MATERIALS AND METHODS:Thirty patients with edentulous or to-be- rendered edentulous mandibles, and 30 with edentulous maxillas, having sufficient bone to allow the placement of four and six implants respectively, of at least 11.5 mm long, were randomised according to a parallel group design into two equal groups and received either 5 mm or 11.5 mm long implants at one centre. Implants had a diameter of 5 mm, were to be placed flapless, and with an insertion torque of at least 50 Ncm. Mandibles received four implants between the mental foramina. Implants were to be immediately loaded with metal-resin definitive prostheses the same day as implant placement. Patients were followed to 5 years post-loading and the outcome measures were: prosthesis and implant failures, complications, and peri-implant marginal bone level changes. RESULTS:Four patients per group dropped out. Two prostheses were remade, one on short maxillary implants and one on long mandibular implants (difference in proportions = 0; 95% CI: -0.15 to 0.15; P = 1.000). Three patients lost six short implants vs three patients who lost four long implants (difference in proportions = 0; 95% CI: -0.19 to 0.19; P = 1.000). Four short implant patients were affected by complications vs five patients with long implants (difference in proportions = 0.04; 95% CI: -0.17 to 0.25; P = 1.000). There were no statistically significant differences for prostheses failures, implant failures and complications. Patients with mandibular short implants lost on average 0.22 mm of peri-implant bone at 5 years while patients with long mandibular implants lost 0.83 mm. Patients with maxillary short implants lost on average 0.30 mm of peri-implant bone at 5 years and patients with long maxillary implants lost 0.89 mm. Short implants showed less bone loss when compared with long implants and the differences up to 5 years were statistically significant both in maxillae (mean difference = 0.59 mm, 95% CI: 0.33 to 0.86 mm, P < .0001) and in mandibles (mean difference = 0.61 mm, 95% CI: 0.36 to 0.86 mm, P < 0.0001). CONCLUSIONS:Flapless-placed 5 mm long implants achieved similar results as 11.5 mm long implants when supporting immediately loaded cross-arch prostheses both in maxillae and mandibles up to 5 years after loading. These results must be confirmed by other trials, and 10 years post-loading data is necessary before making reliable recommendations.
Purpose: To compare the outcome of immediately loaded and one-stage conventionally loaded variable-thread tapered implants in the posterior maxilla. Materials and methods: This study was designed as a split-mouth randomised controlled trial. Twenty-six patients missing teeth bilaterally in the posterior maxilla received three to four implants in each of the posterior sextants. Bone quality was recorded based on Misch criteria (D1-D4) and insertion torque values were measured using a manual wrench. The implants on one side were immediately loaded with a temporary resin fixed partial denture on definitive multi-unit abutments. The implants in the contralateral side received definitive multi-unit abutments according to the one-stage unloaded protocol. Three to 3.5 months following implant placement, the implants were restored with metal-ceramic fixed prostheses. Outcome measures were implant and prosthesis failure rates, complications, and peri-implant bone level changes at 1 year following delivery of the definitive prostheses. Results: Two patients dropped out prior to the delivery of definitive prostheses. Four implants supporting a four-unit immediately loaded prosthesis failed in one patient, 3 months following delivery of the definitive prostheses. None of the conventionally loaded implants or prostheses failed. There were no significant differences in the proportions of implant and prosthesis failures (difference = 4.2%; 95% CI -4.2 to 12.6%; P = 0.999). In the immediately loaded group, four early prosthetic complications occurred during the provisionalization phase (three small resin chippings and one prosthetic screw loosening). No other complications were reported. The difference in the rate of complications between the two interventions was not statistically significant (difference = 16.7%; 95% CI -1.2% to 35.6%; P = 0.125). The 1-year peri-implant marginal bone level changes were evaluated in 23 patients (77 immediately loaded and 76 conventionally loaded implants). On average, patients lost 0.42 mm at the immediately loaded and 0.46 mm at the conventionally loaded implants, the difference being statistically not significant (difference = 0.044 mm; 95% CI -0.27 to 0.18 mm; P = 0.701). Conclusions: Immediate loading of 3- to 4-unit fixed partial prostheses supported by variable-thread implants in the posterior maxilla can yield good and similar 1-year results to one-stage conventionally loaded implants.
PURPOSETo summarise systematic reviews that assess the effects of different interventions for implant prosthetic rehabilitation in partially edentulous patients with the presence of bone atrophy.MATERIALS AND METHODSOnly systematic reviews of randomised controlled trials (RCTs) dealing with partially edentulous adult patients presenting bone defects were included. Treatments of interest were bone augmentation procedures, use of short, tilted or zygomatic implants, sinus lift and transposition of the inferior alveolar nerve. Outcome variables considered were: prosthetic and implant failure, complications, radiological and clinical peri-implant bone level variation, aesthetic and functional satisfaction, and vestibular peri-implant soft tissue recession. A search of systematic reviews of RCTs selected from MEDLINE, the Cochrane Database of Systematic Review, and the Prospero register published in the past 5 years (May 2012 - May 2017) was performed. Systematic reviews were also manually searched. Independent data extraction by two authors using predefined data fields, including ROBIS risk of bias, was executed.RESULTSA total of 12 systematic reviews of RCTs were identified for inclusion in the overview. Eight reviews were considered at low risk of bias. Short implants (≤ 8 mm) were associated with a notable decrease in complications compared to long implants with bone augmentation procedures. Many trials compared different sinus lift procedures and different bone augmentation techniques. None of these indicated that one procedure could reduce prosthetic or implant failures when compared to the other. The use of a membrane can contribute to the regeneration of the hard tissue in horizontal augmentation. Different membranes or bone substitutes did not give substantially different results. No data are available regarding comparisons involving zygomatic implants or tilted implants or transposition of the alveolar nerve.CONCLUSIONSOverall, the evidence is not sufficiently robust to determine the best treatment for implant prosthetic rehabilitation in partially edentulous patients presenting bone atrophy. In terms of vertical defects, if the short implants can be used they should be used because the number of complications are reduced compared to longer implants with sinus lift or bone augmentation. Nevertheless, caution should be exercised because long-term follow-up studies were not available. No conclusions can be drawn regarding the comparison between different vertical bone augmentation techniques in atrophic posterior mandible because quantitative meta-analyses were not performed. With regards to horizontal defects, the use of a membrane appears to increase the regeneration of the hard tissue but no differences were detected in prosthesis or implant failures or in complications.
PURPOSE:The present study evaluated the hypothesis that implants inserted at bone level or supracrestally have different outcomes in single tooth replacements against the alternative hypothesis of no difference.MATERIALS AND METHODS:This study was designed as a randomised, split-mouth, controlled pilot trial. Ten patients, each missing two bicuspids or molars, were treated with 20 implants featuring 0.75 mm of machined collar. Each patient randomly received one implant inserted at bone level (BL) and one inserted 0.75 mm to 1 mm above the alveolar crest (SC), measured with a periodontal probe during surgery. All the implants were inserted into healed healthy bone with an insertion torque ranging between 35 Ncm and 45 Ncm. Both implants were loaded with screw-retained acrylic-resin temporary crowns 3 months after implant insertion and 3 months later with screw-retained zirconia-ceramic definitive crowns. Outcome measures were implant/crown failures, biological and prosthetic complications, radiographic marginal bone level changes (MBL), probing pocket depth (PPD) and bleeding on probing (BOP). Clinical data were collected at baseline (implant insertion) and 1 year after implant placement (9 months after initial loading).RESULTS:After 1 year of follow-up, no patients dropped out, no implants failed, and no complications occurred. The mean MBL at the 1-year follow-up was 0.28 ± 0.21 mm in the SC group and 0.93 ± 0.37 mm in the BL group. While the difference in MBL was statistically significant between the two treatment groups (difference 0.65 ± 0.34; 95% CI = 0.59 to 1.01; P = 0.0001), the soft-tissue parameters were not statistically different. The mean PPD was 2.63 ± 2.4 in the SC group and 2.40 ± 0.70 in the BL group (P = 0.419) and mean BOP was 0.50 ± 0.71 in the SC group and 0.40 ± 0.70 in the BL group (P = 0.754).CONCLUSIONS:The smooth-collar implants inserted supracrestally showed 0.7 mm less radiographic marginal bone loss compared with implants inserted at the bone level 9 months after loading.
