Antero-Posterior Mandibular Excursion in Obstructive Sleep Apnea Patients Treated with Mandibular Advancement Device: A Retrospective Cohort Study.

Since obstructive sleep apnea (OSA) management with a mandibular advancement device (MAD) is likely to be life-long, potential changes in mandibular movements during therapy should be investigated. The purpose of this study was to use a method that has already been shown to be reliable in order to determine whether the range of antero-posterior mandibular excursion, the procedure upon which MAD titration is based, varies between baseline (T0) and at least 1 year of treatment (T1). The distance between maximal voluntary protrusion and maximal voluntary retrusion determined using the millimetric scale of the George Gauge was retrospectively collected from the medical records of 59 OSA patients treated with the MAD and compared between T0 and T1. A regression analysis was performed to evaluate the influence of treatment time, MAD therapeutic advancement and the patient's initial characteristics in excursion range variation. A statistically significant increase of 0.80 ± 1.52 mm (mean ± standard deviation, p < 0.001) was found for antero-posterior mandibular excursion. The longer the treatment time (p = 0.044) and the smaller the patient's mandibular excursion at T0 (p = 0.002), the greater the increase was. These findings could be explained by a muscle-tendon unit adaptation to the forward mandibular repositioning induced by the MAD. During MAD therapy, patients can develop a wider range of antero-posterior mandibular excursion, especially those with a smaller initial excursion capacity.

Maximum voluntary retrusion or habitual bite position for mandibular advancement assessment in the treatment of obstructive sleep apnoea patients.

BACKGROUND: There is no consensus on whether the range of mandibular advancement for the construction of mandibular advancement devices in obstructive sleep apnoea (OSA) patients should be measured from a starting position of maximum voluntary retrusion or habitual bite position. OBJECTIVE: The purposes of this study were to investigate the differences in mandibular advancement registrations starting from maximum voluntary retrusion or from habitual bite position and to evaluate the reliability of these assessments. METHODS: A retrospective cohort analysis of 126 patients with OSA was performed. All patients had their mandibular range of motion evaluated twice (starting from maximum voluntary retrusion and from habitual bite position) through the George Gauge before undergoing drug-induced sleep endoscopy. The Dahlberg formula and paired t test were used to calculate random and systematic errors of dental positions assessment. Test-retest reliability was quantified using the intra-class correlation coefficient (ICC). RESULTS: The mean mandibular range starting from maximum voluntary retrusion and from habitual bite position were 12.49 ± 2.19 mm and 7.68 ± 2.29 mm, respectively, with a mean distance between the two starting positions of 4.81 ± 1.75 mm. No systematic error was found (P > .05), and random errors ranged from 0.30 to 0.95 mm. ICC values were excellent for maximum voluntary protrusion (ICC = 0.986) and maximum voluntary retrusion (ICC = 0.956), whereas habitual bite position showed a good value (ICC = 0.818). CONCLUSION: The difference between maximum voluntary retrusion and habitual bite position is potentially relevant. Maximum retrusion is advisable as starting point of the mandibular advancement registration since it provides a more reliable measure.

Posterior atrophic jaws rehabilitated with prostheses supported by 5 × 5 mm implants with a nanostructured calcium-incorporated titanium surface or by longer implants in augmented bone. Five-year results from a randomised controlled trial.

PURPOSE: To evaluate whether 5 × 5 mm dental implants with a novel nanostructured calcium-incorporated titanium surface could be an alternative to implants at least 10-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 having 5- to 7-mm bone height above the mandibular canal, and 40 patients with atrophic maxillae having 4- to 6-mm bone height 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 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 cemented metal-ceramic or zirconia prostheses were delivered. Patients were followed to 5 years post-loading and the outcome measures were: prosthesis and implant failures, any complication and peri-implant marginal bone level changes. RESULTS: Sixteen patients dropped out before the 5-year evaluation (four short mandibles, three short maxillae, six augmented mandibles and three augmented maxillae). In mandibles, two grafted patients were not prosthetically rehabilitated because of multiple complications, and three implants failed in the same patient (one was a replacement implant) versus one patient who lost his short implant and crown 2 years after loading. In maxillae one short implant failed with its provisional crown 3 months post-loading. There were no statistically significant differences in prostheses (difference in proportion = -0.003; 95% CI: -0.14 to 0.13; P = 1.000) and implant failures (difference in proportion = -0.03; 95% CI: -0.17 to 0.09; P = 0.609) up to 5 years after loading. Significantly more complications occurred at mandibular grafted sites: 17 augmented patients were affected by complications versus nine patients treated with short implants in mandibles (difference in proportion = 0.39; 95% CI: 0.10 to 0.62; P = 0.013). In the maxilla seven sinus-elevated patients versus two patients treated with short implants were affected by complications, the difference not being statistically significant (difference in proportion = 0.25; 95% CI: -0.04 to 0.49; P = 0.128). Patients with mandibular short implants lost on average 1.22 mm of peri-implant bone at 5 years and patients with 10-mm or longer mandibular implants lost 1.70 mm. Patients with maxillary short implants lost on average 1.25 mm of peri-implant bone at 5 years and patients with 10-mm or longer maxillary implants lost 1.73 mm. Longer implants showed a greater bone loss up to 5 years after loading than short implants both in maxillae (mean difference: -0.48 mm; 95% CI: -0.89 to -0.07 mm; P = 0.024) and in mandibles (mean difference: -0.48 mm; 95% CI: -0.79 to -0.18 mm; P = 0.004). CONCLUSIONS: Five years after loading, 5 × 5 mm implants achieved similar results 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, 10-year post-loading data are necessary before making reliable recommendations.

Five-year results from a randomised controlled trial comparing prostheses supported by 5-mm long implants or by longer implants in augmented bone in posterior atrophic edentulous jaws.

PURPOSE: 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. MATERIALS AND METHODS: Fifteen patients with bilateral atrophic mandibles (5 to 7 mm bone height above the mandibular canal) and 15 patients with bilateral atrophic maxillae (4 to 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 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: In five augmented mandibles the planned 10-mm long implants could not be placed and shorter implants (7.0 and 8.5 mm) had to be used instead. Five years after loading, six patients, five treated in the mandible and one in the maxilla, dropped out. Three prostheses (one mandibular and two maxillary) failed in the short-implant group versus none in the long-implant group. In mandibles one long implant failed versus two short implants in one patient. In maxillae one long implant failed versus three short implants in two patients. There were no statistically significant differences in implant (n = 26; P = 1.00, difference = 3.85%, 95% CI: -12.95% to 20.64%) and prosthetic (n = 26; P = 0.250, difference = 11.54%, 95% CI: -0.74% to 23.82%) failures. Eleven patients had 16 complications at short implants (one patient accounted for six complications) and 12 patients had 14 complications at long implants. There were no statistically significant differences in complications (n = 28; P = 1.00, difference = -3.57%, 95% CI: -30.65% to 23.51%). Five years after loading, patients with mandibular implants lost on average 1.72 mm at short implants and 2.10 mm at long implants of peri-implant marginal bone. This difference was statistically significant (difference = 0.37 ± 0.43 mm; 95% CI: 0.07 to 0.68 mm; P = 0.022). In maxillae, patients lost on average 1.31 mm at short implants and 1.79 mm at long implants. This difference was statistically significant (difference = 0.48 ± 0.43 mm; 95% CI: 0.22 to 0.74 mm; P = 0.002). CONCLUSIONS: Five years after loading, 5-mm short implants achieved similar results to longer implants in augmented bone. The choice of short implants might be preferable to vertical bone augmentation, especially in mandibles, since the treatment is faster and cheaper.

Immediate loading of one (fixed-on-1) versus two (fixed-on-2) implants placed flapless supporting mandibular screw-retained cross-arch fixed prostheses: 10-month results from an explanatory randomised controlled trial.

PURPOSE: To evaluate the outcome of one (fixed-on-1, Fo1) versus two (fixed-on-2, Fo2) implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses. MATERIALS AND METHODS: Twenty patients with edentulous or to be rendered edentulous mandibles were randomised to the Fo1 group (10 patients who received three intraforaminal implants but only the mesial implant was actually loaded) and to the Fo2 group (10 patients who received two intraforaminal implants) according to a parallel-group design. To be immediately loaded implants had to be inserted with a minimum torque of 60 Ncm. Outcome measures were prosthesis and implant failures, complications and patient satisfaction for function and aesthetics evaluated up to 10 months post-loading. RESULTS: Flaps were raised in three patients of the Fo1 group and one of the Fo2 group. Two prostheses in each group were delayed loaded at 2 and 3 months, because implants could not be inserted with a torque superior to 60 Ncm. Patients of the Fo2 group received prostheses with 12 teeth whereas Fo1 patients with 8 or 10 teeth. Ten months after loading no drop-out or implant failure occurred, but one Fo2 prosthesis had to be remade because the patient complained it was too short (risk difference = 0.1; 95% CI: -0.19 to 0.40; Fisher's exact test P = 1.000). Three patients were affected by complications in each group (risk difference = 0.0; 95% CI: -0.359 to 0.359; Fisher's exact test; P = 1.000). There were no statistically significant differences for prosthetic failures and complications between groups. Four months after loading, patients of the Fo1 group were less satisfied for function than those of the Fo2 group (difference between the medians [Hodges-Lehmann estimation] = 1; 95% CI: 0 to 2; P = 0.043). No differences were observed for aesthetics (difference between the medians [Hodges-Lehmann estimation] = 0; 95% CI: -1 to 0; P = 0.481), and two Fo1 patients would not undergo the same procedure again (difference in proportions: 0.2; 95% CI: -0.11 to 0.51; P = 0.474). CONCLUSIONS: Preliminary results suggest that immediately loaded cross-arch screw-retained fixed prostheses with 8 to 10 teeth can be supported by only one dental implant at least up to 10 months post-loading; however, the clinical application and usefulness of such a procedure remains questionable.

Natural or palatal positioning of immediate post-extractive implants in the aesthetic zone? Three-year results of a multicentre randomised controlled trial.

PURPOSE: To evaluate whether there is a difference in aesthetic outcomes positioning immediate post-extractive implants in the natural position (where the tooth should have been in relation to adjacent teeth/implants) or approximately 3 mm more palatally. MATERIALS AND METHODS: Just after tooth extraction, 20 patients requiring one single immediate maxillary post-extractive implant, from second premolar to second premolar, were randomly allocated to receive either an implant positioned in the natural 'central' position where the tooth should have been (central group; 10 patients) or approximately 3 mm more palatally (palatal group; 10 patients) according to a parallel-group design at two different centres. When needed, sites were reconstructed and bone-to-implant gaps were filled with granules of anorganic bovine bone, covered by resorbable collagen barriers. Implants were left submerged for 4 months and rehabilitated with provisional crowns, replaced after 4 months by metal-ceramic definitive crowns. Patients were followed to 3 years after loading. Outcome measures were: crown and implant failures, complications, aesthetics assessed using the pink aesthetic score (PES), peri-implant marginal bone level changes and patient satisfaction, recorded by blinded assessors. RESULTS: Three patients from each group dropped out up to 3 years after loading. One implant failed in each group (14%), the difference being not statistically significant (difference in proportion = 0.00; 95% CI: -0.39 to 0.39; P = 1.000). Two palatal group patients and one natural position patient had a complication each, the difference being not statistically significant (difference in proportion = 0.14; 95% CI: -0.28 to 0.52; P = 1.000). Three years after loading, the median PES was 12.5 (interquartile range [IQR] 5.0) for the central and 10.0 (IQR 10.0) for the palatal group, the difference being not statistically significant (median difference = -1.5; 95% CI: -10.0 to 5.0; P = 0.476). Three years after loading, patients of the central group lost 0.25 (IQR 0.40) mm of peri-implant marginal bone and those of the palatal group 0.20 (IQR 0.88) mm, the difference being not statistically significant (median difference = 0.15 mm; P [Mann-Whitney U test] = 0.486). Patients of both groups were equally satisfied at 3 years after loading for both function and aesthetics (both P = 0.699). CONCLUSIONS: These preliminary results suggest that positioning of immediate post-extractive implants 3 mm more palatally may not improve aesthetics; however, the sample size of the present study was very limited, thus larger trials are needed to confirm or reject the present findings. Conflict of interest statement: Mozo-Grau, Valladolid, Spain, the manufacturer of the implants used in this investigation, donated the implants and partially supported this trial; however, data belonged to the authors and by no means did the sponsor interfere with the conduct of the trial or the publication of its results.

Short implants versus longer implants in vertically augmented posterior mandibles: result at 8 years after loading from a randomised controlled trial.

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.

Do we need abutments at immediately loaded implants supporting cross-arch fixed prostheses? Results from a 5-year randomised controlled trial.

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.

Immediate loading of fixed cross-arch prostheses supported by flapless-placed 5 mm or 11.5 mm long implants: 5-year results from a randomised controlled trial.

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.

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

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

Clinical Relevance of Bone Density Values from CT Related to Dental Implant Stability: A Retrospective Study.

PURPOSE: The majority of the techniques used to assess the primary implant stability are subjective and empirical and can be used during or after the surgery. The aim of this study is to evaluate the bone density prior to surgery, in order to give recommendations to the clinician about the best surgical technique and the type of implant which is needed. MATERIALS AND METHODS: A surgeon operated on 75 patients for 269 implants over the period 2010-2014. He required a CT to plan the surgery and he documented the type, the diameters, and the lengths of the implants, the insertion torque, and the ISQ values. At a later stage another clinician measured bone density and cortical thickness. We endeavoured to get the most accurate superimposition between the implants placed by the surgeon and those placed by the clinician. RESULTS: In maxilla ISQ showed a significant positive correlation with HU values detected for coronal-buccal (r = 0.302; p = 0.020) and middle-lingual (r = 0.295; p = 0.023). Torque showed a positive correlation with cortical bone thickness at the middle of the ridge (ρ = 0.196; p = 0.032). CONCLUSION: It is important to take into consideration the Hounsfield Units and the cortical thickness as predictive parameters during the preoperative assessment, with regard to the choice of the implant type as well as the surgical technique.

Immediately loaded zygomatic implants vs conventional dental implants in augmented atrophic maxillae: 1-year post-loading results from a multicentre randomised controlled trial.

PURPOSE: To compare the clinical outcome of immediately loaded cross-arch maxillary prostheses supported by zygomatic implants vs conventional implants placed in augmented bone. MATERIALS AND METHODS: In total, 71 edentulous patients with severely atrophic maxillas without sufficient bone volumes for placing dental implants, or when it was possible to place only two implants in the anterior area (minimal diameter 3.5 mm and length of 8 mm) and less than 4 mm of bone height subantrally, were randomised according to a parallel group design to receive zygomatic implants (35 patients) to be loaded immediately vs grafting with a xenograft, followed after 6 months of graft consolidation by placement of six to eight conventional dental implants submerged for 4 months (36 patients). For immediate loading, zygomatic implants had to be inserted with an insertion torque superior to 40 Ncm. Screw-retained metal reinforced acrylic provisional prostheses were provided, to be replaced by definitive Procera Implant Bridge Titanium prostheses (Nobel Biocare, Göteborg, Sweden), with ceramic or acrylic veneer materials 4 months after initial loading. Outcome measures were: prosthesis, implant and augmentation failures, any complications, quality of life (OHIP-14), patients' number of days with total or partial impaired activity, time to function and number of dental visits, assessed by independent assessors. Patients were followed up to 1 year after loading. RESULTS: No augmentation procedure failed. Five patients dropped out from the augmentation group. Six prostheses could not be delivered or failed in the augmentation group vs one prosthesis in the zygomatic group, the difference being statistically significant (difference in proportions = -16.5%; P = 0.045; 95% CI: -0.34 to -0.01). Eight patients lost 35 implants in the augmentation group vs two patients who lost four zygomatic implants, the difference being statistically significant (difference in proportions = -20.1%; P = 0.037; 95% CI: -0.38 to -0.02). A total of 14 augmented patients were affected by 22 complications, vs 28 zygomatic patients (40 complications), the difference being statistically significant (difference in proportions = 34.8%; P = 0.005; 95% CI: 0.12 to 0.54). The 1-year OHIP-14 score was 3.93 ± 5.86 for augmented patients and 3.97 ± 4.32 for zygomatic patients with no statistically significant differences between groups (mean difference = 0.04; 95% CI: -2.56 to 2.65; P = 0.747). Both groups had significantly improved OHIP-14 scores from before rehabilitation (P < 0.001 for both augmented and zygomatic patients). On average, the number of days of total infirmity was 7.42 ± 3.17 for the augmented group and 7.17 ± 1.96 for the zygomatic group, the difference not being statistically significant (mean difference = -0.25; 95% CI: -1.52 to 1.02; P = 0.692). The number of days of partial infirmity were on average 14.24 ± 4.64 for the augmented group and 12.17 ± 3.82 for the zygomatic group, the difference being statistically significant (mean difference = -2.07; 95% CI: -4.12 to -0.02; P = 0.048). The mean number of days that needed to have a functional prosthesis was 444.32 ± 207.86 for augmented patients and 1.34 ± 2.27 for zygomatic patients, the difference being statistically significant (mean difference = -442.98; 95% CI: -513.10 to -372.86; P < 0.001). The average number of dental visits was 19.72 ± 12.22 for augmented patients and 15.12 ± 5.76 for zygomatic patients, the difference not being statistically significant (mean difference = -4.61; 95% CI: -9.31 to 0.92; P = 0.055). CONCLUSIONS: Preliminary 1-year post-loading data suggest that immediately loaded zygomatic implants were associated with statistically significantly fewer prosthetic failures (one vs six patients), implant failures (two vs eight patients) and time needed to functional loading (1.3 days vs 444.3 days) when compared to augmentation procedures and conventionally loaded dental implants. Even if more complications were reported for zygomatic implants, they proved to be a better rehabilitation modality for severely atrophic maxillae. Long-term data are absolutely needed to confirm or dispute these preliminary results.

Posterior atrophic jaws rehabilitated with prostheses supported by 6 mm long × 4 mm wide implants or by longer implants in augmented bone. 3-year post-loading results from a randomised controlled trial.

PURPOSE: To evaluate whether 6 mm long × 4 mm wide dental implants could be an alternative to implants of at least 10 mm long placed in bone augmented with bone substitutes in posterior atrophic jaws. MATERIALS AND METHODS: A total of 20 patients with bilateral atrophic mandibles, and 20 patients with bilateral atrophic maxillae, having 5 mm to 7 mm of bone height below the maxillary sinus or 6 mm to 8 mm above the mandibular canal, had their side of the jaws randomly allocated according to a split-mouth design. They were allocated to receive one to three 6 mm long × 4 mm wide implants, or implants of at least 10 mm long in augmented bone by two different surgeons at 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. After 4 months, all implants were submerged and loaded with provisional prostheses. Four months later, definitive prostheses were delivered. Outcome measures were prosthesis and implant failures, any complication and radiographic peri-implant marginal bone level changes. RESULTS: Five patients (three treated in mandibles and two in maxillae) dropped out before the 3-year post-loading follow-up. Two short maxillary implants affected by peri-implantitis failed together with their prosthesis vs three mandibular prostheses that could not be placed on implants at least 10 mm long due to graft failures; one was associated with the loss of three implants because of infection. There were no statistically significant differences in implant (difference in proportions = 0.000; 95% CI: -0.140 to 0.140; P = 1.000) and prosthesis failures (difference in proportions = 0.057; 95% CI: -0.094 to 0.216; P = 0.625). In total, 18 complications occurred in 13 patients at augmented sites vs four complications in three patients with 6 mm long implants. Significantly more complications occurred at grafted sites in mandibles (difference in proportions = 0.353; 95% CI: 0.005 to 0.616; P = 0.031), but not in maxillae (difference in proportions = 0.222; 95% CI: -0.071 to 0.486; P = 0.219). In mandibles, patients with 6 mm long implants lost an average of 1.25 mm of peri-implant bone at 3 years vs 1.54 mm in patients with implants of at least 10 mm long. The difference was statistically significant (mean difference = 0.29 mm; 95% CI: 0.08 to 0.51 mm; P = 0.010). In maxillas, patients with 6 mm-long implants lost an average of 1.28 mm of peri-implant bone at 3 years vs 1.50 mm in patients with implants of at least 10 mm long. The difference was statistically significant (mean difference = 0.22 mm; 95% CI: 0.08 to 0.35 mm; P = 0.003). CONCLUSIONS: Results at 3 years 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.

Immediately loaded zygomatic implants vs conventional dental implants in augmented atrophic maxillae: 4 months post-loading results from a multicentre randomised controlled trial.

PURPOSE: To compare the clinical outcome of immediately loaded cross-arch maxillary prostheses supported by zygomatic implants vs conventional implants placed in augmented bone. MATERIALS AND METHODS: A total of 71 edentulous patients with severely atrophic maxillas, who did not have sufficient bone volume to place dental implants or when it was possible to place only two implants in the front area (minimal diameter 3.5 mm and length of 8 mm) and less than 4.0 mm of bone height subantrally, were randomised according to a parallel group design. They (35 patients) received zygomatic implants to be loaded immediately vs grafting with a xenograft, followed, after 6 months of graft consolidation, by the placement of six to eight conventional dental implants, submerged for 4 months (36 patients). To be loaded immediately, zygomatic implants had to be inserted with an insertion torque superior to 40 Ncm. Screw-retained, metal-reinforced, acrylic provisional prostheses were provided to be replaced by definitive Procera Implant Bridge Titanium prostheses (Nobel Biocare, Göteborg, Sweden) with ceramic or acrylic veneer materials 4 months after initial loading. Outcome measures were: prosthesis, implant and augmentation failures, any complications, quality of life (OHIP-14), the number of days that patients experienced total or partial impaired activity, time to function, and number of dental visits, assessed by independent assessors. Patients were followed up to 4 months after loading. RESULTS: No augmentation procedure failed. Three patients dropped out from the augmentation group. Six prostheses could not be delivered or failed in the augmentation group vs one prosthesis in the zygomatic group, the difference being statistically significant (difference in proportions = 15.32%; P = 0.04; 95% CI: 0.23 to 31.7). Eight patients lost 35 implants in the augmentation group vs three implants in one patient from the zygomatic group, the difference being statistically significant (difference in proportions = 21.38%; P = 0.001; 95% CI: 3.53 to 39.61). In total, 14 augmented patients were affected by 20 complications vs 26 zygomatic patients (35 complications), the difference being statistically significant (difference in proportions = 31.87%; P = 0.008; 95% CI: 6.48 to 53.37). The OHIP-14 score was 3.68 ± 5.41 for augmented patients and 4.97 ± 5.79 for zygomatic patients, with no statistically significant differences between groups (mean difference = 1.29; 95%CI -1.60 to 4.18; P = 0.439). Both groups had significantly improved OHIP-14 scores from before rehabilitation (P < 0.001 for both augmented and zygomatic patients). The number of days of total infirmity was, on average, 7.42 ± 3.17 for the augmented group and 7.17 ± 1.96 for the zygomatic group, the difference not being statistically significant (mean difference = -0.25; 95% CI: -1.52 to 1.02; P = 0.692). Days of partial infirmity were on average 14.24 ± 4.64 for the augmented group and 12.17 ± 3.82 for the zygomatic group, the difference being statistically significant (mean difference = -2.07; 95% CI: -4.12 to -0.02; P = 0.048). The mean number of days to have a functional prosthesis was 444.32 ± 207.86 for augmented patients and 1.34 ± 2.27 for zygomatic patients, the difference being statistically significant (mean difference = -442.9; 95% CI: -513.10 to -372.86; P < 0.001). The average number of dental visits was 16.79 ± 10.88 for augmented patients and 12.58 ± 5.21 for zygomatic patients, the difference not being statistically significant (mean difference = -4.21; 95% CI -8.48 to 0.06; P = 0.053). CONCLUSIONS: Preliminary 4-months post-loading data suggest zygomatic implants were associated with statistically significantly less prosthetic (one vs six patients) and implant failures (one patient lost three implants versus 35 implants in eight patients) as well as time needed to functional loading (1.3 days vs 444.3 days) when compared with augmentation procedures and conventionally loaded dental implants. Even if more complications were reported for zygomatic implants, which were solved spontaneously or could be handled, zygomatic implants proved to be a better rehabilitation modality for severely atrophic maxillae. Long-term data are essential to confirm or dispute these preliminary results. Conflict of interest statement: This study was originally supported by Nobel Biocare, the manufacturer of the implants, and the provisional and definitive prosthetic components used in this study, which were provided free for the patients. However, before any results were known, Nobel Biocare withdrew the financial support and recruitment had to be stopped. Tecnoss (Giaveno, Torino, Italy) kindly donated the bone substitutes and the membranes, whereas Global D (Brignais, France) donated the osteosynthesis screws. Data property belonged to the authors and by no means did the manufacturers interfere with the publication of the results.

Posterior atrophic jaws rehabilitated with prostheses supported by 5 × 5 mm implants with a nanostructured calcium-incorporated titanium surface or by longer implants in augmented bone. 3-year results from a randomised controlled trial.

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.

Early loading of maxillary titanium implants with a nanostructured calcium-incorporated surface (Xpeed): 5-year results from a multicentre randomised controlled trial.

PURPOSE: To evaluate clinical safety and effectiveness of a novel calcium-incorporated titanium implant (Xpeed, MegaGen Implant Co. Limited, Gyeongbuk, South Korea). MATERIALS AND METHODS: In total, 60 patients were randomised to receive one to six titanium 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 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: A total of 30 patients received 45 calcium-incorporated implants and 30 patients were given 42 control titanium implants. Five years after loading, eight patients dropped-out from the Xpeed group and nine left the RBM group. No prosthesis or implant failures occurred. Two patients were affected by three complications in the Xpeed group vs five patients from the RBM group, who experienced eight complications; the difference between groups being not statistically significant different (P = 0.187; difference in proportions = 14.7%; 95% CI: -10.7% to 39.4%). Five years after loading patients with Xpeed implants lost on average 1.19 ± 0.48 mm of peri-implant marginal bone vs 1.43 ± 0.98 mm of patients with RBM implants, the difference being not statistically significant (P = 0.35; mean difference: -0.23 mm; 95% CI: -0.73 to 0.27 mm). CONCLUSIONS: Both implant surfaces provided good clinical results and no significant difference was found when comparing titanium implants with a nanostructured calcium-incorporated surface with implants with an RBM surface. Conflict-of-interest statement: MegaGen partially supported this trial and donated the implants and prosthetic components. The study design was negotiated with MegaGen Implant Co, Gyeongbuk, South Korea, however, data property belonged to the authors and by no means did MegaGen interfere with the conduct of the trial or the publication of its results.

Interpositional Augmentation Technique in the Treatment of Posterior Mandibular Atrophies: A Retrospective Study Comparing 129 Autogenous and Heterologous Bone Blocks with 2 to 7 Years Follow-Up.

The aim of this retrospective study was to compare clinical and radiographic outcomes of the interpositional (inlay) augmentation technique in atrophic posterior partially edentulous mandibles using three different types of block bone grafts: autogenous bone block harvested from the iliac crest, deproteinized bovine bone mineral block, and collagenated equine bone block. A total of 115 patients were included with a 4.2-year mean after-loading follow-up. Data seem to suggest that heterologous bone blocks are similar in results to autogenous bone blocks, so they might be considered preferable as they avoid invasive harvesting surgeries.

Conventional drills vs piezoelectric surgery preparation for placement of four immediately loaded zygomatic oncology implants in edentulous maxillae: results from 1-year split-mouth randomised controlled trial.

PURPOSE: To compare the outcome of site preparation for zygomatic oncology implants using conventional preparation with rotary drills or piezoelectric surgery with dedicated inserts for placing two zygomatic implants per zygoma according to a split-mouth design. MATERIALS AND METHODS: Twenty edentulous patients with severely atrophic maxillas not having sufficient bone volume for placing dental implants and less than 4 mm of bone height subantrally had their hemi-maxillas randomised according to a split-mouth design into implant site preparation with conventional rotational drills or piezoelectric surgery. Two zygomatic oncology implants (unthreaded coronal portion) were placed in each hemi-maxilla. Implants that achieved an insertion torque superior to 40 Ncm were immediately loaded with screw-retained metal reinforced acrylic provisional prostheses. Outcome measures were: prosthesis and implant failures, any complications, time to place the implants, presence of post-operative haematoma, and patient's preference by independent assessors. All patients were followed up to 1 year after loading. RESULTS: In two patients drills had also to be used at the piezoelectric surgery side to enable implant sites to be prepared. One implant for the conventional drill group did not achieve an insertion torque superior to 40 Ncm since it fractured the zygoma. No patients dropped out and two distal oncology implants failed in the same patient (one per group), who was not prosthetically rehabilitated. Six complications occurred at drilled sites and three at piezoelectric surgery sites (two patients had bilateral complications), the difference being not statistically significant (P (McNemar's test) = 0.375; odds ratio = 4.00; 95% CI of odds ratio: 0.45 to 35.79). Implant placement with convention drills took on average 14.35 ±â€…1.76 min and with piezoelectric surgery 23.50 ±â€…2.26 min, implant placement time being significantly shorter with conventional drilling (difference = 9.15 ±â€…1.69 min; 95%CI: 8.36 to 9.94 min; P < 0.001). Post-operative haematomas were more frequent at drilled sites (P = 0.001), and 16 patients found both techniques equally acceptable, while four preferred piezoelectric surgery (P = 0.125). CONCLUSIONS: Both drilling techniques achieved similar clinical results, but conventional drilling required 9 min less and could be used in all instances, although it was more aggressive. These results may be system-dependent, therefore they cannot be generalised to other zygomatic systems with confidence. Conflict-of-interest statement: This study was partially supported by Southern Implants (Irene, South Africa), the manufacturer of the zygomatic implants and the conventional drills evaluated in this study. However, data property belonged to the authors and by no means did the manufacturer interfere with the conduct of the trial or the publication of its results. Drs Felice and Pistilli developed the piezoelectric surgery zygomatic insert used in the present study.

Posterior jaws rehabilitated with partial prostheses supported by 4.0 x 4.0 mm or by longer implants: One-year post-loading results from a multicenter randomised controlled trial.

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) jaws 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, 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 1-year post-loading and outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone level changes. RESULTS: Seventy-five patients were randomly allocated to each group. One patient dropped out after the 4-month post-loading evaluation from the long implant group. Up to 1-year post-loading, 3 patients lost one 4.0 mm-long implant each in comparison to 2 patients who lost one long implant each (difference in proportion = 0.013; 95% CI: -0.058 to 0.087; P = 0.506). All failures occurred before loading, the failed implants were replaced and the delivery of two prostheses in each group was delayed for several months (difference in proportion = 0.0004; 95% CI: -0.068 to 0.069; P = 0.685). Three short implant patients experienced three complications versus 2 long implant patients (difference in proportion = 0.013; 95% CI: -0.058 to 0.087; P = 0.506). There were no statistically significant differences in prosthesis failures, implant failures and complications. Patients with short implants lost on average 0.53 mm of peri-implant bone and patients with longer implants lost 0.57 mm. There were no statistically significant differences in bone level changes up to 1 year between short and long implants (mean difference = 0.038 mm; 95% CI: -0.068 to 0.138; P = 0.198). CONCLUSIONS: One year after loading 4.0 mm-long implants achieved similar results as 8.5 mm-long or longer implants in posterior jaws, however 5- to 10-year post-loading data are necessary before reliable recommendations can be made.

Periodontal status after surgical-orthodontic treatment of labially impacted canines with different surgical techniques: A systematic review.

INTRODUCTION: Good periodontal status is essential for a successful treatment outcome of impacted maxillary canines. Whereas the surgical technique used for tooth uncovering has been shown not to affect the final periodontal status of palatally impacted canines, its effect on labially impacted canines is still unclear. METHODS: Searches of electronic databases through January 2015 and reference lists of relevant publications were used to identify studies evaluating the periodontal status of labially impacted canines after combined surgical-orthodontic treatment. Two reviewers independently screened the articles, extracted data, and ascertained the quality of the studies. RESULTS: Ninety-one studies were identified; 3 were included in the review. No included study examined the periodontal outcome of the closed eruption technique. Excisional uncovering was reported to have a detrimental effect on the periodontium (bleeding of the gingival margin, 29% vs 7% in the control group; gingival recession, -0.5 mm [SD, 1.0] vs -1.5 mm [SD, 0.8] in the control group; and width of keratinized gingiva, 2.6 mm [SD, 1.4] vs 4.1 mm [SD, 1.5] in the control group). Impacted canines uncovered with an apically positioned flap had periodontal outcomes comparable with those of untreated teeth. CONCLUSIONS: The current literature is insufficient to determine which surgical procedure is better for periodontal health for uncovering labially impacted canines.