One-Year Multicenter Randomised Controlled Trial Comparing OT Equator® and Locator Attachments to Retain an Early Loaded Implant Overdenture on Two Implants.

This investigation aimed to compare the effectiveness of the OT Equator® (Rhein, Bologna, Italy) and the Locator attachment systems used to retain early loaded implant-retained overdentures. This study was designed as a multicenter randomised controlled trial of parallel groups. After implant placement, the patients were randomised to receive OT Equator® attachments in the test group or Locator attachments in the control group. The outcome measures were implant and prosthetic success and survival rates, any biological and technical complication, marginal bone loss, patients' satisfaction, and periodontal parameters. Overall, 42 patients were consecutively enrolled and treated. One implant was lost in the control group, while no implants were lost in the test group. No prostheses failed in both groups. Only a few complications were experienced in both groups. The main was represented by loss of retention of the attachments (retentive caps). The OT Equator® attachment showed statistically lower periodontal parameters. In conclusion, both attachment systems were suitable for overdenture implant retention.

Five-Year Prospective Study on Implant Failure and Marginal Bone Remodeling Expected Using Bone Level Implants with Sandblasted/Acid-Etched Surface and Conical Connection.

OBJECTIVE: The purpose of the present prospective, case-series study was to report implant survival rate and marginal bone remodeling expected 5 years after loading using dental implants placed in daily practice. MATERIALS AND METHODS: This research was designed as an open-cohort, prospective, case-series evaluation. Any partially or completely edentulous patient, scheduled to receive at least one bone level implant, was considered eligible for this study. Primary outcome measurements were: implant and prosthetic cumulative survival rate and any complications experienced up to the 5-year follow-up. Secondary outcome measures were: thickness of gingival biotype, implant insertion torque, implant stability quotient, and marginal bone loss (MBL). RESULTS: Ninety consecutive patients (34 males and 56 females, aged between 24 and 81 years old [mean: 53.2 ± 15.4]) with 243 inserted implants were followed for at least 5 years after loading (mean: 65.4 ± 3.1 months; range from 60 to 72). At the 1-year follow-up, no drop-outs were recorded, but 17 patients (18.9%) with 18 restorations (12.6%) delivered on 34 implants (14%) were lost at the 5-year examination. At the 5-year follow-up examination, six implants lost osseointegration (97.5%). In the same period, four prostheses failed (97.2%). Five complications were reported in five different patients (prosthetic success rate was 96.5%, at patient level). Five years after loading, the mean MBL was 0.41 ± 0.30 mm. The difference from the 1-year data was 0.04 ± 0.19 mm. A statistically significant higher MBL was found for smokers, and patients with thin gingival biotype. The mean implant insertion torque was 42.9 ± 4.8 Ncm (range from 15 to 45 Ncm). Two-hundred and three implants (83.5%) were inserted with an insertion torque ≥35 and ≤45 Ncm. CONCLUSIONS: High implant survival and success rate could be expected with stable marginal bone remodeling up to 5 years after loading. Smoking and thin tissue biotype were the most important variabilities associated with higher MBL. Further research studies are needed to confirm these results.

New Generation of Fixture-Abutment Connection Combining Soft Tissue Design and Vertical Screw-Retained Restoration: 1-Year Clinical, Aesthetics and Radiographic Preliminary Evaluation.

Implant design factors and the abutment connection are correlated with crestal bone stability. The aim of the present study was to evaluate a new type of screw-retained prostheses delivered on tissue-level implants with conical external vertical seal and internal hexagon connection. Implants 4.25 mm in diameter and 10 mm in length (Prama, Sweden and Martina) were placed in partially edentulous patients needing at least one implant in the healed site, having sufficient bone volume. The implant neck was positioned above the bone crest. A healing abutment was placed according to a one-stage approach. Outcome measures were implant and prosthesis survival rate, any complications, marginal bone loss (MBL), periodontal parameters, and pink esthetic score (PES). Overall, 13 patients (4 women and 9 men; mean age 50 ± 22 years) with the same number of implants were treated and followed for one year after loading. At the 12-month follow up, no implant and no prosthesis failed, and no complications were experienced. The mean MBL experienced at the one year follow-up was 0.65 ± 0.48 mm. One year after loading, 2 out of 13 implants present bleeding on probing (15.4%), 4 out of 13 patients presented with plaque at the one year of follow-up (30.8%) and the PES was 10.5 ± 2.3 mm. Within the limitations of the present study, the analyzed implants seem to be a viable treatment option for the rehabilitation of a single tooth gap.

1-Year Evaluation of OT Bridge Abutments for Immediately Loaded Maxillary Fixed Restorations: A Multicenter Study.

OBJECTIVE: Preliminary data on survival and success rates of immediately loaded, maxillary, screw-retained, implant-supported, fixed restorations delivered on narrow and low-profile OT Equator abutments (OT Bridge, Rhein'83) were evaluated. MATERIALS AND METHODS: This retrospective study evaluated data collected from patients rehabilitated with OT Bridge prosthetic concept between November 2017 and February 2019 in six different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. RESULTS: A total of 76 implants were inserted in 14 patients. Patients were followed for a mean period of 15.8 months (range = 12-24). All the patients receive OT Equator (Rhein'83) as intermediate abutments. One year after loading, one implant failed (1.3%). None of the prosthesis failed. One prosthetic complication was experienced in one patient. Three out of 76 implants were connected to the prosthetic framework using only the Seeger system, without screw. Difference in OHIP values was statistically significant (71.9 ± 8.5; p = 0.000). One year after loading, MBL was 0.21 ± 0.11 mm and p-value was 0.000. One year after loading, 8.7% of the examined implant sites present positive bleeding on probing, while 6.4% of the implant sites presented plaque. CONCLUSION: The OT Equator abutments (Rhein'83) showed successful results when used to support maxillary fixed dental prosthesis delivered on four to six implants. High implant and prosthetic survival rates, very low complications, high patient satisfaction, and good biological parameters, including only 0.2 mm of bone remodeling were experienced one year after function. Further studies are needed to confirm these preliminary results.

Histological and Histomorphometric Evaluation of Post-Extractive Sites Filled with a New Bone Substitute with or without Autologous Plate Concentrates: One-Year Randomized Controlled Trial.

The purpose of the present study was to evaluate the histological and histomorphometric characteristics of post-extraction sites grafted with decellularized bovine compact bone from bovine femur, mixed and unmixed with leukocyte- and platelet-rich fibrin after four months of healing. This study was designed as a randomized controlled trial of parallel groups. Patients in need of a single, implant-supported restoration to replace a hopeless tooth were recruited for tooth extraction and implant placement four months after socket preservation procedure. After tooth extraction, patients were randomly allocated to receive decellularized bovine compact bone from bovine femur, mixed and unmixed with leukocyte- and platelet-rich fibrin. After four months of healing, tapered implants were inserted with an insertion torque between 35 and 45 Ncm. Two months later, implants were loaded with screw-retained definitive crowns. Outcome measures were implant (ISR) and prosthesis (PSR) survival rates, complications, histological and histomorphometric analyses, radiographic marginal bone-level changes, and patients' satisfaction. Clinical data were collected up to one year after tooth extraction and socket preservation procedures. Thirty patients were consecutively enrolled in the trial (15 in each group). Unfortunately, due to the COVID-19 pandemic, bone samples were collected only in 19 patients. Two implants failed before definitive prosthesis delivery (ISR 93.3%). No prosthesis failed (PSR 100%). Three complications were experienced in the control group. The mean bone percentage was 40.64 ± 18.76 in the test group and 33.40 ± 22.38 in the control group. The difference was not statistically significant (p = 0.4846). The mean soft tissue percentage was 32.55 ± 19.45 in the test group and 55.23 ± 17.64 in the control group. The difference was statistically significant (p = 0.0235). The mean residual graft was 24.59 ± 18.39 in the test group and 11.37 ± 12.12 in the control group. The difference was not statistically significant (p = 0.0992). Mean marginal bone loss, as well as patient satisfaction, showed no differences between groups. With the limitations of the present study, socket preservation with L-PRF mixed with decellularized bovine compact bone demonstrated favorable results, comparing with decellularized bovine compact bone from bovine femur alone. Further studies with larger sample size and longer follow-up are needed to confirm these preliminary results.

Role of New Hydrophilic Surfaces on Early Success Rate and Implant Stability: 1-Year Post-loading Results of a Multicenter, Split-Mouth, Randomized Controlled Trial.

OBJECTIVE: To compare early implant failure and implant stability of one-stage Hiossen ET III implants with its new hydrophilic (NH) surface, compared with Hiossen ET III implants with the sandblasted and acid-etched (SA) surface at 1-year follow-up. MATERIALS AND METHODS: This study was designed as a split-mouth, multicenter randomized controlled trial aimed to compare SA surface implants (SA group) and NH surface, (NH group). Outcomes were implant and prosthetic survival rates, complications, the insertion torque at implant placement, and implant stability quotient (ISQ) values. RESULTS: Twenty-nine patients (mean age 59.9 ± 11.3 years) were treated and followed up to 1 year after loading. No patient dropped out. Fifty-eight implants (29 SA group and 29 NH group) were placed. No implants or prostheses failed and no complications were experienced during follow-up. The mean insertion torque was 40.5 ± 3.23 (38.17-41.83) Ncm in the SA group and 40.48 ± 3.49 (38.02-41.98) Ncm in the NH group (p = 0.981). There was a statistically significant difference at the second week (T2) with higher values in the NH group (p = 0.041). Similar results were found in the maxilla (p = 0.045), but not in the mandible (p = 0.362). A positive correlation was found between initial insertion torque and ISQ with higher value in the NH group (0.73 vs. 0.66). CONCLUSIONS: NH implants are a viable alternative to SA surface, as they seem to avoid the ISQ drop during the bone remodeling phase.

Three-Year Retrospective Comparative Study between Implants with Same Body-Design but Different Crest Module Configurations.

Crest module can be defined as the portion of a two-piece implant designed to retain the prosthetic components and to allows the maintenance of the peri-implant tissues in the transition zone. AIM: To evaluate the three-year after loading clinical and radiographic data, collected from patients that received a prosthetic rehabilitation on conical connection implants with partial machined collar (PMC; CC Group) and same body-designed implants, with flat-to-flat connection and groovy neck design (FC Group). MATERIALS AND METHODS: A retrospective chart review of previously collected data, including documents, radiographs, and pictures of patients who received at least one implant-supported restoration on NobelReplace CC PMC or NobelReplace Tapered Groovy implants was performed. Patients with at least three years of follow-up after final loading were considered for this study. Outcomes measures were implant and prosthesis failures, any biological or technical complications, marginal bone loss. RESULTS: Eight-two patients (44 women, 38 men; average age 55.6) with 152 implants were selected and divided in two groups with 77 (CC group) and 75 (FC group), respectively. Three years after final loading, one implant in CC group failed (98.7% survival rate), while no implants failed in FC group (100% survival rate). One restoration failed in CC group (98.7% survival rate) with no restoration failing in the FC one (100% survival rate). Differences were not statistically significant (p = 1.0). Three years after final loading, mean marginal bone loss was 0.22 ± 0.06 mm (95% CI 0.2-0.24) in CC group and 0.62 ± 0.30 mm (95% CI 0.52-0.72) in FC group. The difference was statistically significant (0.40 ± 0.13 mm; 95% CI 0.3-0.5; p = 0.003). CONCLUSION: with the limitation of this retrospective comparative study, implants with conical connection and partial machined collar seem to achieve a trend of superior outcomes if compared with implants with flat connection and groovy collar design.

Errors in Implant Positioning Due to Lack of Planning: A Clinical Case Report of New Prosthetic Materials and Solutions.

The achievement of the optimal implant position is a critical consideration in implant surgery, as it can facilitate the ideal prosthesis design and allow adequate oral hygiene maintenance. The switch from bone-driven to prosthetic-driven implant placement, through a comprehensive diagnosis and adequate treatment plan, is a prerequisite for long-term successful implant-based therapy. The aim of the present case report is to describe a step-by-step prosthetic retreatment of a patient with primary treatment failure due to incorrect dental implant placement. Although dental implants achieve high survival rates, the success of implant prosthetic therapy significantly relies on an appropriate implant position. Malpositioned implants can cause damage to vital structures, like nerves or vessels. Moreover, improper implant positioning can result in esthetic, biological, and technical complications and can, in extreme situations, render the desired prosthetic rehabilitation impossible to achieve.

Effectiveness of Ball Attachment Systems in Implant Retained- and Supported-Overdentures: A Three- to Five-Year Retrospective Examination.

PURPOSE: To evaluate implant and prosthetic survival rates, complications, patient satisfaction, and biological outcomes of patients rehabilitated with a ball attachment system for implant retained- and supported-overdentures (IOV), which was in function for 3 to 5 years. METHODS: This retrospective study evaluated data collected from patients treated between April 2001 and May 2018 with IOV on splinted and non-splinted implants and a ball attachment system. Patients were followed for 36 to 206 months (mean follow-up was 128.1 ± 51.9 months). Data were collected at the 3- and 5-year follow-up examination. Outcome measures were implant and prosthetic survival rates, technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), and periodontal parameters (bleeding on probing and plaque index). RESULTS: A total of 46 patients (16 males and 30 females) with 124 implants were included in this study. Twenty-five implant-retained overdentures were delivered on 53 unsplinted implants, while the other 21 patients received an implant-supported overdentures and the implants were splinted. At the five-year follow-up examination, one implant and one prosthesis failed in the unsplinted group, resulting in a cumulative survival rate of 97.8% at the patient level. Two minor technical complications were experienced. CONCLUSIONS: Implant overdenture retained or supported by ball attachment systems showed high implant and prosthetic survival and success rates. A low number of complications, high patient satisfaction, and successful biological parameters were experienced in the mid-term follow-up. Data need to be confirmed by further randomized trials.

Do the New Hydrophilic Surface Have Any Influence on Early Success Rate and Implant Stability during Osseointegration Period? Four-Month Preliminary Results from a Split-Mouth, Randomized Controlled Trial.

OBJECTIVE: The objective of this study is to compare the implant stability of Hiossen ET III implants with its new hydrophilic (NH) surface and Hiossen ET III implants with the sandblasted and acid-etched (SA) surface. MATERIALS AND METHODS: Patients required at least two teeth to be rehabilitated with a fixed, implant-supported restoration, consecutively enrolled. Patients randomly received SA surface implants (SA group) or SA implants with a newly developed bioabsorbable apatite nanocoating (NH group). Outcome measures were implant and prosthetic survival rate, complications, insertion torque, and implant stability quotient (ISQ) measured at implant placement and every week up to 8 weeks after implant placement. Comparison between groups was made by unpaired t-test, while the comparison between each follow-up will be made by paired t-tests to detect any change during the follow-up. Complications and failures were compared using Fisher's exact test. RESULTS: A total of 14 patients were treated with 28 implants (14 SA and 14 NH). No implant and prosthesis failed 4 months after implant placement. No complications were experienced. At the 2nd week after implants placement, two implants in the SA group showed discontinuous measurements versus none in the NH group (p = 0.4815). Implants unscrewed during ISQ measurements and were rescrewed. Data recording stopped for 6 weeks. Both implants osseointegrated without any further complication. The NH implants did not show physiological ISQ decrease between 2nd and 4th week after implant placement, showing a more even pattern of ISQ values compared with SA implants (77.1 ± 4.6 vs. 72.9 ± 11.5; difference: 4.2 ± 12.1; p = 0.258). High ISQ values were found in both groups at each time point. CONCLUSIONS: NH implants are a viable alternative to SA surface, as they seem to avoid the ISQ drop during the remodeling phase.

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.

Accuracy of computer-assisted template-based implant placement using conventional impression and scan model or intraoral digital impression: A randomised controlled trial with 1 year of follow-up.

PURPOSE: To compare accuracy and complications of computer-assisted template-based implant placement using conventional impression and scan of a physical stone cast or intraoral scanning to rehabilitate partially edentulous patients. MATERIALS AND METHODS: Any partially edentulous patients with at least five residual teeth, requiring at least one implant to be planned on three-dimensional (3D) cone beam computed tomography (CBCT) scan according to a computer-assisted template-based protocol were enrolled. Patients were randomised according to a parallel-group design into two arms: intraoral digital impression (fully digital group) or conventional impression and scan model (conventional group). Implants were placed flapless or with a minimally invasive flap, and conventionally loaded after 5 months. Outcome measures were implant and prosthetic success, complications, accuracy and peri-implant marginal bone loss. Three deviation parameters (angular, horizontal and vertical) were defined to evaluate the discrepancy between the planned and placed implant positions. Results were compared using a mixed-model repeated-measures analysis of variance (α = 0.05). RESULTS: Twenty patients (11 females and 9 males; mean age 44.6 years old) were randomised to the fully digital group (10 patients with 28 implants) or conventional group (10 patients with 29 implants). No patients dropped out. No implant or prosthesis failed up to 1 year after loading. One implant in the fully digital group was placed freehand due to limited inter-arch space. No biological or mechanical complications were experienced during follow-up. Difference between groups were not statistically significant (P = 0.999). The mean error in angle was 2.25 ± 1.41 degrees (range 0.30 to 5.00 degrees; 95% CI: 1.38 to 3.12 degrees) in the fully digital group and 2.10 ± 1.18 degrees (range 0.30 to 5.80 degrees; 95% CI: 1.37 to 2.83 degrees) in the conventional group. The difference was not statistically significant (-0.15 ± 1.63 degrees; range -3.20 to 2.90 degrees; 95% CI: -0.87 to 0.57 degrees; P = 0.668); in the horizontal plane (mesio-distal), the mean error was 0.52 ± 0.30 mm (range 0.10 to 1.10 mm; 95% CI: 0.33 to 0.70 mm) in the fully digital group and 0.44 ± 0.26 mm (range 0.10 to 0.90 mm; 95% CI: 0.27 to 0.60 mm) in the conventional group. The difference was not statistically significant (-0.08 ± 0.38 degrees; range -1.0 to 0.60 degrees; 95% CI: -0.32 to 0.16 degrees; P = 0.279); in the vertical plane (apico-coronal), the mean error was 0.58 ± 0.44 mm (range 0.00 to 1.60 mm; 95% CI: 0.31 to 0.85) in the fully digital group and 0.46 ± 0.34 mm (range 0.00 to 1.20 mm; 95% CI: 0.25 to 0.67) in the conventional group. The difference was not statistically significant (-0.12 ± 0.59 degrees; range -1.20 to 1.00 degrees; 95% CI: -0.49 to 0.24 degrees; P = 0.250). One year after loading, the mean marginal bone loss was 0.14 ± 0.12 mm (range -0.10 to 0.40 mm; 95% CI: 0.07 to 0.21 mm) in the fully digital group and 0.18 ± 0.13 mm (range -0.10 to 0.60 mm; 95% CI: 0.09 to 0.26 mm). The difference was not statistically significant (-0.04 ± 0.19 mm; range -0.50 to 0.30 mm; 95% CI: -0.16 to 0.08 mm; P = 0.294). CONCLUSIONS: With the limitations of the present trial, implant rehabilitations planned using intraoral digital impressions showed similar results compared to conventional impression and scan model. Digital impression may be a viable option for the rehabilitation of partial edentulous patients when computer-guided template-assisted implant placement is used.

Accuracy of Computer-Assisted Template-Based Implant Placement Using Two Different Surgical Templates Designed with or without Metallic Sleeves: A Randomized Controlled Trial.

Purpose: To compare virtual planning accuracy of novel computer-assisted, template-based implant placement techniques, which make use of CAD/CAM stereolithographic surgical templates with or without metallic sleeves. Furthermore, to compare open versus closed sleeves for templates without metallic sleeves. Materials and methods: Any partially edentulous patients requiring at least one implant to be placed according to a computer-assisted template-based protocol were enrolled. Patients were randomized according to a parallel group design into two arms: Surgical template with or without metallic sleeves. Three deviation parameters (angular, horizontal, vertical) were defined to evaluate the discrepancy between the planned and placed implant positions. Results: No implants failed, and no complications were experienced. Forty-one implants were placed using surgical templates with metallic sleeves while 49 implants were placed with a surgical template without metallic sleeves. Of these, 16 implants were placed through open sleeves and 33 through closed sleeves. There was a statistically significant difference in angle (p = 0.0212) and in the vertical plan (p = 0.0073) with lower values for implants placed with a surgical template without metallic sleeves. In the test group, close sleeves were more accurate compared with open sleeves in angle (p = 0.0268) and in horizontal plan (p = 0.0477). Conclusion: With the limitations of the present study, surgical templates without metallic sleeves were more accurate in the vertical plan and angle compared to the conventional template with metallic sleeves. Open sleeves should be used with caution in the molar region only in case of reduced interarch space. Further research is needed to confirm these preliminary results.

Multicenter Retrospective Analysis of Implant Overdentures Delivered with Different Design and Attachment Systems: Results Between One and 17 Years of Follow-Up.

PURPOSE: To analyze implant and prosthetic survival rates, complications, patient satisfaction, and biological parameters of patients rehabilitated with implant overdentures (IOV) on splinted and nonsplinted implants and different attachment systems, in function for one to 17 years. METHODS: This retrospective study evaluated data collected from patients rehabilitated with implant overdentures between January 2001 and December 2016 in nine different centers. Outcome measures were implant and prosthetic success rates, mechanical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. RESULTS: A total of 581 implants were installed in 194 patients. Patients were followed for a mean period of 60.6 months (range 6⁻206). Eighty-nine patients received 296 low profile attachment (OT Equator), 62 patients received 124 ball attachments, and 43 patients received 107 Locator attachments. In eighty-three patients the implants were splinted with computer aided design/computer aided manufacturing (CAD/CAM) or casted bar. At the last follow-up, 10 implants failed in eight patients. Statistical significance was found for failed prostheses (P = 0.0723) and complications (P = 0.0165), with better values for splinted implants. No statistically significant differences were found in proportion of implant and prosthetic failure (P > 0.05). At a five-year follow-up, proportion of complications (P = 0.0289) and failed prostheses (P = 0.0069) were statistically higher for IOV on Locator attachments. No difference was founded in MBL at one- and two-year follow-up between different attachment systems (P > 0.05). Statistically significant improvement in all the OHIP categories was reported in all the patients, after one year of function. CONCLUSIONS: Implant overdenture showed high implant and prosthetic survival rates, low complications, high patient satisfaction, and good biological parameters in the long-term follow-up. Splinting the implants may reduce number of mechanical complications. Locator attachments showed higher number of complications. Further studies are needed to confirm these preliminary results.

Survival and Success Rates of Different Shoulder Designs: A Systematic Review of the Literature.

OBJECTIVES: To identify whether there is a relationship between different implant shoulder positions/orientations/designs and prosthetic and/or implant failures, biological or mechanical complications, radiographic marginal bone loss (MBL), peri-implant buccal recession (RC), aesthetic scores (Papilla Index, PES, and WES), and patient satisfaction after a minimum of 1 year function in the aesthetic zone, compared to the two-piece, conventional implant neck architecture. MATERIALS AND METHODS: The systematic review was written according to the PRISMA guidelines. The search strategy encompassed the English literature from 1967 to September 2016 and was performed online (in the PubMed database of the U.S. National Library of Medicine, Embase, and the Cochrane Library) to identify relevant studies that met the inclusion criteria. The assessment of quality and risk of bias of the selected manuscripts was performed according to the guidelines provided by CONSORT and STROBE statements. RESULTS: A total of 16 articles (7 randomized controlled trials, 4 observational comparative studies, and 5 systematic reviews) were selected to fulfill the inclusion criteria. A trend of higher implant failure and prosthetic complications were experienced in the one-piece group compared to the two-piece group, although no statistically significant differences were found. Higher marginal bone loss was found in the test group (one-piece, scalloped implants) compared to the control group (two-piece, flat implants). No comparative studies reporting data on sloped implants were found that fulfilled the inclusion and exclusion criteria of this systematic review. No differences were experienced between groups regarding aesthetic outcomes and patient satisfaction. CONCLUSIONS: There was sufficient evidence that different implant shoulder positions/orientations/designs (scalloped, sloped, and one piece) offer no benefit when compared to two-piece, conventional flat implants. Current evidence is limited due to the quality of available studies.

Natural or palatal positioning of immediate post-extractive implants in the aesthetic zone? 1-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 about 3 mm more palatally. MATERIALS AND METHODS: Just after tooth extraction, 30 patients requiring one single immediate maxillary post-extractive implant, from second 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; 15 patients) or about 3 mm more palatally (palatal group; 15 patients) according to a parallel group design at three 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 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 satisfaction, recorded by blinded assessors. RESULTS: Two patients from the palatal group dropped-out up to 1 year after loading. One implant failed in each group (6.7%), the difference being not statistically significant (difference in proportion = -0.01; 95% CI -0.20 to 0.18; P (Fisher's exact test) = 1.000). One patient from the central group was affected by one complication, vs two palatal group patients (two complications); the difference being not statistically significant (difference in proportion = -0.09; 95% CI -0.32 to 0.15; P (Fisher's exact test) = 0.583). One year after loading, the mean PES was 9.93 ± 2.67 for the central and 8.75 ± 4.37 for the palatal group; the difference being not statistically significant (mean difference = 1.18; 95% CI: -1.87 to 4.23; P (t test) = 0.427). One year after loading, patients in the central group lost on average 0.23 ± 0.17 mm of peri-implant marginal bone and those of the palatal group 0.24 ± 0.25 mm, the difference being not statistically significant (mean difference = -0.01; 95% CI: -0.23 to 0.21; P (t test) = 0.926). Patients in both groups were equally satisfied at 1 year after loading for both function and aesthetics (P (Mann-Whitney U test) = 0.494 and P (Mann-Whitney U test) = 0.076, respectively). CONCLUSIONS: These preliminary results suggest that positioning of immediate post-extractive implants 3 mm more palatally is not improving aesthetics, however, the sample size of the present study was limited, thus larger trials are needed to confirm of reject the present findings.

Computer-guided vs freehand placement of immediately loaded dental implants: 5-year postloading results of a randomised controlled trial.

PURPOSE: To compare planning and patient rehabilitation using 3D implant planning software and dedicated surgical templates with conventional freehand implant placement for the rehabilitation of partially or fully edentulous patients using flapless or mini-flap procedures and immediate loading. MATERIALS AND METHODS: Patients requiring at least two implants to be restored with a single prosthesis, having at least 7 mm of bone height and 4 mm in bone width were consecutively enrolled. Patients were randomised according to a parallel group study design into two groups: computerguided group or conventional freehand group. Implants were loaded immediately with a provisional prosthesis, replaced by a definitive prosthesis 4 months later. Outcome measures assessed by a blinded independent assessor were: implant and prosthesis failures, any complications, marginal bone levels, number of treatment sessions, duration of treatment, post-surgical pain and swelling, consumption of pain killers, surgical and prosthetic time, time required to solve complications, and patient satisfaction. Patients were followed up to 5 years after loading. RESULTS: Ten patients (32 implants) were randomised to the computer-guided group and 10 patients (30 implants) were randomised to the freehand group. At the 5-year follow-up examination one patient of the computer-guided group and one of the freehand group dropped-out (both moved to another country). No prostheses failed during the entire follow-up. Two implants failed in the conventional group (6.6%) vs none in the computer-guided group (P = 0.158). Ten patients (five in each group) experienced 11 complications (six in the computer-guided group and five in the freehand group), that were successfully solved. Differences between groups for implant failures and complications were not statistically significant. Five years after loading, the mean marginal bone loss was 0.87 mm ± 0.40 (95% CI: 0.54 to 1.06 mm) in the computer-guided group and 1.29 mm ± 0.31 (95% CI: 1.09 to 1.51 mm) in the freehand group. The difference was statistically significant (difference 0.42 mm ± 0.54; 95% CI: 0.05 to 0.75; P = 0.024). Patient self-reported post-surgical pain (P = 0.037) and swelling (P = 0.007) were found to be statistically significant higher in patients in the freehand group. Number of sessions from patient's recruitment to delivery of the definitive prosthesis, number of days from the initial CBCT scan to implant placement, consumption of painkillers, averaged surgical, prosthetic, and complication times, were not statistically significant different between the groups. At the 5-year followup, all the patients were fully satisfied with the function and aesthetics of their definitive prostheses. CONCLUSIONS: Both approaches achieved successful results over the 5-year follow-up period. Statistically higher post-operative pain and swelling were experienced at sites treated freehand with flap elevation. Less marginal bone loss (0.4 mm) was observed in the computer-guided group, at 5 years follow-up.

Definitive Abutments Placed at Implant Insertion and Never Removed: Is It an Effective Approach? A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PURPOSE: To assess whether repeated abutment disconnections and reconnections have any impact on peri-implant bone resorption and soft tissue healing. MATERIALS AND METHODS: Electronic and manual searches were conducted for English-language articles published up to March 2017 that identified a relation between repeated disconnections of implant abutments (PA group) and prosthetic or implant failures, complications, marginal bone loss (MBL), soft tissue healing, and esthetic evaluation (pink esthetic score [PES]) after at least 1 year of function compared with implants receiving a final abutment at the time of implant placement (DA group). RESULTS: Fourteen articles (535 patients with 994 implants) were selected for qualitative analysis. Six of these were included in the meta-analysis. Five prostheses failed in the PA group and 1 failed in the DA group (P = .1047). Seven biologic complications occurred in the PA group and 6 occurred in the DA group (P = .8121). MBL was significantly less in the DA group (difference, 0.279 mm; P = .000). Greater buccal recession occurred in the PA group (difference, 0.198 mm; P = .0004). The PES evaluation showed no differences between groups (P = .289). CONCLUSIONS: Repeated abutment disconnections and reconnections considerably increased MBL and buccal recession. Further studies are needed to confirm these results.

Sinus lift grafting with anorganic bovine bone vs 50% autologous bone mixed with 50% anorganic bovine bone: 2 years after loading results from a randomised controlled trial.

PURPOSE: To compare the outcome of implants inserted in maxillary sinuses augmented with anorganic bovine bone (ABB) grafts vs mixed 50% ABB and 50% autologous bone graft, using a lateral window approach. MATERIALS AND METHODS: This study was designed as a randomised controlled trial of parallel groups. Patients in need of an implant-supported prosthesis in a maxillary posterior area with a residual alveolar bone height no greater than 4 mm (range 0-4 mm) were recruited for lateral sinus grafting. Patients were randomly allocated to receive 50% ABB and 50% autogenous bone (group A) or 100% ABB (group B). After 7 months, tapered implants were inserted with an insertion torque between 20 and 45 Ncm. After 3 months, implants were loaded with screw-retained temporary crowns. Definitive crowns were delivered 3 months later. Outcome measures were implant survival, complications, radiographic marginal bone-level changes, probing pocket depths (PPD) and bleeding on probing (BOP). Clinical data were collected at definitive prosthesis delivery, 1 and 2 years after loading. RESULTS: Thirty-two consecutive patients were treated with 32 sinus lift procedures (16 group A, 16 group B). A total of 46 implants were installed. No patient dropped out. No crown/implant failed by the end of the study. Three complications (one sinus membrane perforation and two chipping of the ceramic) were observed in three patients in group A, vs none in group B (RR 0.81; 95% CI 0.64 - 1.03 mm; P = 0.225). At the 2-year after final loading follow-up, the mean marginal bone loss was 1.18 ± 0.50 mm (95% CI 0.95 - 1.45 mm) in group A and 1.28 ± 0.48 mm (95% CI 0.97 - 1.43 mm) in group B, with no statistically significant differences between the two groups (difference 0.11 ± 0.22 mm; 95% CI -0.06 - 0.16 mm; P = 0.586). At the same follow-up, the mean PPD value was 2.70 ± 0.39 for group A and 2.54 ± 0.66 for group B, with no statistically significant difference between groups (difference 0.17 ± 0.39 mm; 95% CI 0.06 - 0.32 mm; P = 0.456), while the mean BOP value was 1.21 ± 0.79 for group A and 1.28 ± 0.68 for group B, (difference: 0.06 ± 0.49 mm; 95% CI -0.23 - 0.25 mm; P = 0.297). CONCLUSIONS: Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of implants inserted in sinuses grafted with ABB vs implants inserted in sinuses grafted with mixed 50% ABB and 50% autologous bone are comparable. Conflict-of-interest statement: This study was not supported by any company. All the authors declare no conflict of interest.

Crestal sinus lift using an implant with an internal L-shaped channel: 1-year after loading results from a prospective cohort study.

PURPOSE: To evaluate the clinical and radiographic outcomes of a one-stage crestal sinus elevation procedure using a self-tapping endosseous implant system (iRaise, Maxillent, Herzliya, Israel) developed for sinus augmentation, 1 year after loading. MATERIALS AND METHODS: Patients needing restoration in the posterior maxilla with a residual alveolar crest of 3 to 8 mm in height and 5 mm in width distal to the canine as measured on CBCT scan were treated using the iRaise sinus lift system. Outcome measures were: implant and prosthetic failures, any complications, increased bone height (iBH), marginal bone loss (MBL), implant stability quotient (ISQ), radiographic tissue remodelling patterns using the sinus grafting remodelling index (SGRI), volumetric measurements of sinus graft, patient self-reported post-surgical swelling, consumption of pain medication and histological analysis. RESULTS: A total of 30 consecutive participants with a mean age of 54.2 ± 9.4 years underwent a transcrestal elevation of the sinus membrane, insertion of bone graft, and implant placement. A total of 50 implants were placed (30 iRaise system implants and 20 adjunctive iSure implants, Maxillent). The mean follow-up was 15.8 ± 2.1 months after implant loading. One patient dropped out at the 1-year after loading follow-up examination. No implants and no prostheses failed during the entire follow-up. One patient experienced a small membrane tear. Before implant insertion, the mean residual alveolar ridge height was 4.64 ± 0.86 mm (range: 3.4-6.4 mm; 95% CI: 4.39-5.01 mm). One year after loading, the bone height was 16.86 ± 3.13 mm (95% CI 15.83-18.07 mm). At the 1-year after loading follow-up, the mean MBL was 0.19 ± 1.05 mm (95% CI 0.02-0.78 mm). The mean ISQ at implant placement was 65.2 ± 5.4 (95% CI 63.6-67.4) and increased during the healing period reaching the mean value of 73.6 ± 3.7 (95% CI 73.1-75.9; range 62-79). The difference was statistically significant (8.4 ± 5.3; 95% CI 5.9-39.7; P = 0.0000). One year after loading, SGRI score was evaluated in 23 implants. Overall, the mean SGRI value was 2.29 ± 2.41 mm (95% CI 1.22-2.98 mm). Bone volume at implant placement was 2.41 ± 0.25 CC (95% CI 2.22-2.48 CC). During the 6-month, submerged healing period, a slight bone contraction of 11.3% were observed. (2.13 ± 0.24 CC;95% CI 2.02-2.26; difference = 0.27 ± 0.25 CC; 95% CI 0.10-0.36; P = 0.0011). At the first year post-loading period, the bone graft remained stable (2.11 ± 0.22 CC; 95% CI 2.02-2.24). The difference was not statistically significant (0.02 ± 0.07 CC; 95% CI 0.01-0.04; P = 0.2166). From the patient's point of view, the mean pain value was 0.52 ± 0.74 (range 0-3); mean swelling value was 0.27 ± 0.52 (range 0-2); and the mean consumption of analgesic was 0.87 ± 4.94 tablets (range 0-4) 3 days after surgery. Morphological and histomorphometric analyses showed that all the samples had a normal structure without inflammatory infiltrate, six months after healing. The following fractions (%) were found: bone (immature bone + mature bone): 44.07 ± 4.91; residual biomaterial: 23.98 ± 2.64; medullary spaces: 31.95 ± 3.16. CONCLUSIONS: Sinus floor augmentation can be successfully accomplished with a transcrestal approach using a dedicated implant system. A physiologic contraction of 11.3% of the original volume of the bone graft was experienced during the first 6 months of healing; afterwards, no additional graft volume reduction was observed. Long-term clinical studies are needed to confirm these preliminary results.