International Journal of Oral Implantology, 01/2017

Purpose: To compare the clinical outcome of single implants placed immediately after tooth extraction with implants placed 6 weeks after tooth extraction (immediate-delayed placement), and with implants placed after 4-month extraction and socket healing (delayed placement). Materials and methods: Two-hundred and ten (210) patients requiring a single implant-supported crown to replace a tooth to be extracted were randomised to receive immediate post-extractive implants (70 patients), immediate-delayed implants at 6 weeks (70 patients), and delayed implants after 4 months of healing (70 patients) according to a parallel group design. When needed, patients of the immediate and immediate-delayed group had the socket grafted with a bone substitute and covered with a resorbable membrane at implant placement. Sockets randomised to delayed implants were grafted in the same manner if poorly preserved or in the aesthetic areas (from second upper to second upper premolars). Implants inserted with at least 25 Ncm torque were left to heal unloaded for 4 months, whereas those inserted with less than 25 Ncm were left to heal unloaded for 6 months. Temporary crowns were delivered and were to be replaced by definitive ones after 4 months. Outcome measures were crown and implant failures, complications, peri-implant marginal bone level changes, aesthetically assessed using the pink esthetic score (PES), and patient satisfaction recorded by blinded assessors. Patients were followed up to 1 year post-loading. Results: One year after loading, three patients dropped out from the immediate group, five from the immediate-delayed group, and six from the delayed group. Four implants (6%) failed in the immediate, four (6.2%) in the immediate-delayed, and one (1.6%) from the delayed group (P (chi-square test) = 0.369). Apart from the crowns (which failed due to implant losses), no other crown had to be remade. Six immediate, six immediate-delayed and four delayed implants were affected by one complication each (P (chi-square test) = 0.792). Mean peri-implant marginal bone loss after 1 year was -0.25 ± 0.17 mm (CI 95% -0.29; -0.20) at immediate, -0.29 ± 0.14 mm (CI 95% -0.32; -0.25) at immediate-delayed, and -0.31 ± 0.16 mm (CI 95% -0.35; -0.27) at delayed placed implants (P (Kruskal-Wallis test) = 0.015). One year after loading, the mean total aesthetic score was 12.52, 12.49 and 11.78 at the immediate, immediate-delayed and delayed groups, respectively (P (Kruskal-Wallis test) <0.001). All patients were fully satisfied both with function and aesthetics, and would undergo the same procedure again, with four exceptions (one from the immediate, one from the immediate-delayed and two from the delayed group), who were only partially satisfied with aesthetics (P = 0.785). Conclusions: No statistically significant differences for failures, complications and patient satisfaction were observed when placing single implants immediately, 6 weeks or 4 months after tooth extraction; nevertheless, failures were more frequent at immediate and immediate-delayed placed implants. Bone level changes were similar between the different procedures, but aesthetics were better results at immediate and immediate-delayed implants. Keywords: delayed implants, immediate-delayed implants, immediate post-extractive implants, single implants, socket preservation Conflict-of-interest statement: This trial was partially funded by Nobel Biocare Services (code: 2010-894), the manufacturer of the implants evaluated in this investigation; however, 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 whether it is more effective to complete endodontic treatment in a single visit or in two visits with 1-week intracanal calcium hydroxide medication in symptomatic teeth and teeth with periapical lesions. Materials and methods: One hundred and ninety-nine patients, with one symptomatic tooth or a tooth with a periapical lesion, were randomised, according to a parallel group design, to receive a complete endodontic treatment in a single visit (99 patients) or in two visits with 1-week intracanal calcium hydroxide medication (100 patients), at two centres. Patients were followed for up to 1 year post-treatment and the outcome measures were tooth loss, radiographic healing, any complication, post-treatment pain and amount of painkillers used. Results: Seven patients dropped out from the single-visit and ten patients from the two-visit group (all patients from one centre only). One patient lost his tooth from the single-visit and two patients from the two-visit group (difference in proportion = -0.01; 95% CI: -0.05 to 0.03; P = 0.619). Five single-visit patients and nine two-visit patients experienced one complication each (difference in proportion = -0.05; 95% CI: -0.12 to 0.03; P = 0.278). There were no statistically significant differences in tooth loss and complications. One year after treatment, complete radiographic healing was observed in 22 patients of the single-visit group and in 19 patients of the two-visit group; improvement in 43 patients of the single-visit group and in 54 patients of the two-visit group; and no changes/worsening in 24 patients of the single-visit group and in 15 patients of the two-visit group. There were no statistically significant differences in radiographic healing between the two groups (P = 0.509). Pre-treatment pain was reported by 68 single-visit patients and by 68 two-visit patients; 1-week post-treatment pain was reported by 27 single-visit patients and by 46 two-visit patients, and 2-week post-treatment pain was reported by 2 single-visit patients and 11 two-visit patients. For the first week, an average of 0.53 ± 1.23 tablets was taken by single-visit patients and 1.44 ± 3.32 tablets by two-visit patients. For the second week, no single-visit patients needed tablets and in the two-visit group the average was 0.37 ± 1.72 tablets. Patients of the two-visits group had statistically significant more post-treatment pain at 1 (P = 0.002) and 2 weeks (P = 0.011), and took more ibuprofen tablets at 1 (difference = -0.92; 95% CI: -1.62 to -0.21; P = 0.011) and 2 weeks after treatment (difference = -0.37; 95% CI: -0.72 to -0.03; P = 0.033), than in patients treated in a single visit. Conclusions: One year after treatment, both groups achieved similar clinical results; however, patients endodontically treated in a single visit suffered less postoperative pain and took less analgesics than patients treated in two visits, therefore a single-visit treatment should be recommended. Keywords: apical periodontitis, radiographic evaluation, randomised controlled trial, root canal treatment, single visit Conflict-of-interest statement: This trial was self-funded and the authors have no conflict of interests to declare, however, rotary instruments were kindly provided by Sweden & Martina, Due Carrare PD, Italy.

Purpose: To evaluate the safety and clinical efficacy of a novel surface treatment (SurfLink, Nano Bridging Molecules, Gland, Switzerland) on titanium dental implants. SurfLink consists of a monolayer of permanently bound multiphosphonic acid molecules, which mimics the surface of naturally occurring hydroxyapatite. Materials and methods: Twenty-three patients requiring at least two single dental implants had their sites randomised according to a split-mouth design to receive one titanium grade 4 implant treated with SurfLink and one untreated control implant. Additional SurfLink-treated implants were placed if needed. Implants were submerged for 3 months in mandibles and 6 months in maxillae, then loaded with definitive metal-ceramic crowns and followed for 3 years after loading. Outcome measures were crown/implant failures, any complication, radiographic peri-implant marginal bone level changes and marginal bleeding. Results: Three patients dropped out but all remaining patients were followed up to 3-years post-loading. No implant failed. Complications were reported for three patients, affecting both types of implant in two patients and only SurfLink implant in one patient. No differences for complications between the two implant types was observed (McNemar test, P = 1, difference in proportions = -0.04, 95% CI: -0.22 to 0.14). No bleeding was observed when a periodontal probe was run in the peri-implant soft tissues around any of the implants, with the exception of three implants affected by peri-implantitis. There were no statistically significant differences in marginal bone level changes between the two groups (at 3 years post-loading P = 0.86, mean difference = -0.05; SD = 1.15; 95% CI: -0.56 to 0.47). Conclusions: Medium-term data (3-years post-loading) of implants with a biomimetic monolayer of permanently bound multiphosphonic acid molecules (SurfLink surface treatment) presented no safety issues. Clinical healing in both control and SurfLink-treated implant groups was uneventful and did not differ significantly. More challenging clinical situations need to be investigated to evaluate the real effectiveness of this surface treatment. Keywords: biomimetic, dental implant, efficacy, multiphosphonic acid surface treatment, safety Conflict-of-interest statement: Marco Esposito and Ivan Dojcinovic declare that they have no conflict of interest, and they acted as consultants for Nano Bridging Molecules (NBM). Sabrina Buchini, Péter Péchy and Björn-Owe Aronsson are employed at NBM. NBM, the manufacturer of the SurfLink surface treatment, supported and carefully monitored this trial without interfering with the presentation of its results.

Purpose: To evaluate the influence of at least three abutment changes in conventionally loaded implants against placement of a definitive abutment in immediately non-occlusal loaded implants on hard and soft tissue changes. Materials and methods: Eighty patients requiring one single crown or one fixed partial prosthesis supported by a maximum of three implants were randomised, after implants were placed with more than 35 Ncm, according to a parallel group design to receive definitive abutments which were loaded immediately (definitive abutment or immediate loading group) or transmucosal abutments. These were delayed loaded after 3 months and were removed at least three times: 1) at impression taking (3 months after implant placement); 2) when checking the zirconium core on titanium abutments at single crowns or the fitting the metal structure at prostheses supported by multiple implants; 3) at delivery of the definitive prostheses (repeated disconnection or conventional loading group). Patients were treated in four centres and each patient contributed to the study with only one prosthesis followed for 1 year after initial loading. Outcome measures were: prosthesis failures, implant failures, complications, pink esthetic score (PES), buccal recessions, patient satisfaction, peri-implant marginal bone level changes and height of the keratinised mucosa. Results: Forty patients were randomly allocated to each group according to a parallel group design. Two patients dropped out from the definitive abutment group but no implant failed. Four provisional and one definitive single crowns had to be remade (due of misfitting) and one definitive crown (due to ceramic fracture) in the repeated disconnection group versus one provisional prosthesis of the immediate loading group due to frequent debondings (difference = 12%; CI95%: 0%, 25%; P = 0.109). Eight patients were affected by complications: four patients from each group (difference = 1%; CI95%: -13%, 14%; P = 1). PES scores assessed at 1 year post-loading were 11.4 (1.5) mm for the definitive abutment group and 11.0 (2.0) mm for the repeated abutment changes group (difference = 0.4; CI95%: -0.4, 1.2; P = 0.289). Buccal recessions at 1 year post-loading amounted to 0.07 (0.35) mm for the definitive abutment group and 0.12 (0.65) mm for the repeated abutment changes group (actually it was a soft tissue gain; difference = 0.05 CI 95%: -0.19, 0.29; P = 0.659). All patients declared to be very satisfied or satisfied with the function and aesthetics of the prostheses and would undergo the same procedure again. Mean peri-implant marginal bone loss at 1 year after loading was 0.06 (0.12) mm for the definitive abutment group and 0.23 (0.49) mm for the repeated abutment changes group (difference = -0.16; CI95%: -0.33,-0.00; P = 0.046). The height of the keratinised mucosa at 1 year post-loading was 2.8 (1.5) mm for the definitive abutment group and 2.8 (1.7) mm for the repeated abutment changes group (difference = -0.0; CI 95%: -0.8, 0.7); P = 0.966. Up to 1 year after initial loading, there were no statistically significant differences between the two procedures, with the exception of 0.16 mm more marginal bone loss at implants subjected to three abutment removals. Conclusions: One-year post-loading data showed that repeated abutment changes significantly increased bone loss of 0.16, but this difference cannot be considered clinically relevant, therefore clinicians can use the procedure they find more convenient for their specific patient. In addition, immediately non-occlusally loaded dental implants are a viable alternative to conventional loading. Keywords: dental implant, immediate loading, peri-implant marginal bone levels, repeated abutment changes Conflict-of-interest statement: This trial was partially funded by Dentsply Sirona Implants, the manufacturer of the implants and other products evaluated in this investigation. However, 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 with exception of rejecting the proposal of changing the protocol, after the trial was started, allowing the use of indexed abutments.

Purpose: To evaluate whether there are some clinical benefits by placing single dental implants either 0.5 or 1.5 mm subcrestally in healed bone crests. Materials and methods: Sixty partially edentulous patients requiring two single implant-supported crowns had both sites randomly allocated either to 0.5 mm or 1.5 mm subcrestal implant placement according to a split-mouth design at six centres. Implants were submerged in aesthetic areas or non-submerged in non-aesthetic areas for 3 months. Provisional acrylic crowns were delivered and were replaced after 2 months by definitive metal-ceramic crowns. Patients were followed to 1 year after loading. Outcome measures were: crown and implant failures; complications; aesthetics assessed using the pink esthetic score (PES); peri-implant marginal bone level changes; and patient preference, recorded by blinded assessors. Results: One patient dropped out. One patient lost both implants to infection at impression taking. Three complications affected three patients of the 0.5 mm group and two complications affected two patients of the 1.5 mm subcrestally placed implants. One patient had complications at both implants. There were no statistically significant differences for complications between group (difference of proportion = 0.02; 95% CI -0.06 to 0.09; P (McNemar test) = 1.000). At delivery of definitive crowns, 2 months after loading, the mean aesthetic score was 11.22 ± 1.91 and 11.12 ± 1.59 for the 0.5 and 1.5 mm group, respectively. At 1 year after loading, the mean aesthetic score was 12.09 ± 1.66 and 12.10 ± 1.52 for the 0.5 and 1.5 mm group, respectively. There were no statistically significant differences between the two groups at 2 months (P (paired t test) = 0.626) or at 1 year (P (paired t test) = 0.920). One year after loading, patients of the 0.5 mm lost on average 0.21 ± 0.51 mm and those of the 1.5 mm group 0.11 ± 0.36 mm, the difference being not statistically significant (difference = 0.10; 95% CI -0.01 to 0.20; P (paired t test) = 0.078). Patients did not prefer any depth of the implant placement over the other. There were no differences in outcomes between centres. Conclusions: No statistical or clinical differences were noticed when placing implants 0.5 mm or 1.5 mm subcrestally, therefore clinicians can do as they prefer. Keywords: dental implant, subcrestal placement, aesthetics, bone levels Conflict-of-interest statement: Anthogyr (Sallanches, France), the manufacturer of the implants used in this investigation, partially funded this trial and donated the implants and the prosthetic components, 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.

Purpose: To report on the outcome of 7 mm long implants in the rehabilitation of posterior areas of atrophic jaws 3 years after loading. Materials and methods: This prospective study included 127 patients treated with 217 implants supporting 165 fixed prostheses. Final abutments were delivered at surgery stage and in the large majority of patients (n = 116) the implants (n = 199) were loaded after 4 months. Primary outcome measures were implant success and prosthetic success calculated at patient level; secondary outcome measures were complications, and marginal bone level changes calculated at patient level. Results: Thirteen patients with 21 implants dropped out of the study after 3 years. Implant losses occurred in 10 of the 127 patients and 14 of the 217 implants placed failed, giving a cumulative success rate of 93.7% at 3 years, using the patient as unit of analysis. Eight prosthetic failures occurred in six patients, rendering a prosthetic success rate 95.3% at patient level. The average (standard deviation) marginal bone resorption after 3 years of follow-up was 1.46 mm (0.78 mm). Complications occurred in 13 patients (10.2%) and 15 implants (6.9%). Conclusions: Within the limitations of this study, 7 mm long implants in posterior atrophic jaws can be a viable treatment option given the good prosthetic and implant success rates, low marginal bone loss and low incidence of complications. Nevertheless, longer follow-ups are needed to validate the long-term outcome. Keywords: dental prosthesis, implant-supported, humans, follow-up study Conflict-of-interest statement: This study was funded by grant no. 2015-1378 from Nobel Biocare Services. Paulo Maló is currently a consultant for Nobel Biocare. The remaining authors declare no conflicts of interest.

Objective: The aim of this study was to assess whether cone beam computed tomography (CBCT) may be used for clinically reliable alveolar bone quality assessment in comparison to its clinical alternatives, multislice computed tomography and the gold standard (micro-CT). Materials and methods: Six dentate mandibular bone samples were scanned with seven CBCT devices (ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170, Carestream 9300, Scanora 3D, I-CAT Next generation), one micro-CT scanner (SkyScan 1174) and one MSCT machine (Somatom Definition Flash) using two protocols (standard and high-resolution). MSCT and CBCT images were automatically spatially aligned on the micro-CT scan of the corresponding sample. A volume of interest was manually delineated on the micro-CT image and overlaid on the other scanning devices. Alveolar bone structures were automatically extracted using the adaptive thresholding algorithm. Based on the resulting binary images, an automatic 3D morphometric quantification was performed in a CT-Analyser (Bruker, Kontich, Belgium). The reliability and measurement errors were calculated for each modality compared to the gold standard micro-CT. Results: Both MSCT and CBCT were associated with a clinically and statistically (P <0.05) significant measurement error. Bone quantity-related morphometric indices (bone volume fraction 8.41% min to 17.90% max, bone surface density -0.47 mm-1 min to 0.16 mm-1 max and trabecular thickness 0.15 mm min to 0.31 mm max) were significantly (P <0.05) overestimated, resulting in significantly (P <0.05) closer trabecular pores (total porosity percentage -8.41% min to -17.90% max and fractal dimension 0.08 min to 0.17 max) in all scanners compared to micro-CT. However, the structural pattern of the alveolar bone remained similar compared to that of the micro-CT for the ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170 and Carestream 9300. On the other hand, the Scanora 3D, i-CAT Next Generation, standard and high-resolution MSCT displayed an overrated bone quantity and aberrant structural pattern compared to other scanning devices. The calculation of morphometric indices had an overall high reliability (intraclass correlation coefficient [ICC] 0.62 min to 0.99 max), except for the i-CAT Next Generation CBCT (ICC 0.26 min to 0.86 max) and standard resolution MSCT (ICC 0.10 min to 0.62 max). Conclusions: This study demonstrated that most CBCT machines may be able to quantitatively assess alveolar bone quality, with a level of accuracy and reliability that approaches micro-CT. One may therefore propose to extrapolate this to clinical CBCT imaging, certainly when there is a need for implant rehabilitation in dentate jaw bones. Keywords: bone quality, cone beam CT, multislice CT, micro-CT, alveolar bone, presurgical planning Conflict-of-interest statement: There is no conflict of interest to declare. Funding: Fellowship support was received from Research Foundation Flanders (FWO) from the Belgian government and from the Coordination for the Improvement of Higher Education Personnel (CAPES) programme, Science without Borders, from the Brazilian government.

This section presents a brief review of articles on dental implants considered of special interest for the reader, in order to encourage the developing of research, the interest for data analysis and the attention to scientific publications. Your comments are welcome. Please contact Dr Michele Nieri at: michelenieri@gmail.com.