Clinical and Radiological Outcomes of Two Implants with Different Prosthetic Interfaces and Neck Configurations: Randomized,Controlled, Split‐Mouth Clinical Trial

Background: Peri‐implant bone loss seems to occur following implant placement/loading regardless of all the efforts to eliminate it. Several factors, including surgical trauma, biologic width establishment, lack of passive fit of the superstructures, implant‐abutment microgap, and occlusal overloading, may increase peri‐implant bone loss. Over the years, new interface designs were introduced and clinical studies suggest that internal conical connection and platform shifting may be advantageous for marginal bone preservation. Purpose: To compare clinical and radiological outcomes of two implant designs with different prosthetic interfaces and neck configurations in a randomized, controlled, split‐mouth clinical trial. Materials and Methods: Thirty‐four partially edentate patients randomly received at least one internal conical connection with back‐tapered collar and platform shifting design or external‐hexagon implants with flat‐to‐flat implant‐abutment interface. Primary end point was peri‐implant bone level changes at different time points, failures of implants and/or prosthesis, any complications, implant stability quotient (ISQ) values, and periodontal parameters. Results: No dropout occurred. Marginal bone changes were statistically significantly different with better results for the internal conical connection. No implants and prosthesis failures have been observed, yielding a cumulative survival rate of 100%. A high ISQ value was found for both implants, and no statistically significant difference was found for ISQ mean values between interventions at each time point (p > .05). All implants showed no bleeding on probing and a very slight amount of plaque at the 1‐year‐in‐function visit. Conclusions: Both implant designs investigated performed similarly in terms of failure rates, providing successful results up to 1 year after loading. The back‐tapered neck configuration with conical connection and built‐in platform shifting showed statistically lower marginal bone loss than straight neck configuration with flat‐to‐flat implant‐abutment interface and external‐hexagonal connection.     

Comparison of Peri‐Implant Soft Tissue Parameters and Crestal Bone Loss Around Immediately Loaded and Delayed Loaded Implants in Smokers and Non‐Smokers: 5‐Year Follow‐Up Results

Background: The aim of this study is to compare peri‐implant soft tissue parameters (plaque index [PI], bleeding on probing [BOP], and probing depth [PD] ≥4 mm) and crestal bone loss (CBL) around immediately loaded (IL) and delayed loaded (DL) implants in smokers and non‐smokers. Methods: Thirty‐one patients with IL implants (16 smokers and 15 non‐smokers) and 30 patients with DL implants (17 smokers and 13 non‐smokers) were included. Personal data regarding age, sex, and duration and daily frequency of smoking were gathered using a questionnaire. Peri‐implant PI, BOP, and PD ≥4 mm were recorded, and mesial and distal CBL was measured on standardized digital radiographs. Multiple group comparisons were performed using the Bonferroni post hoc test (P <0.05). Results: All implants replaced mandibular premolars or molars. Mean scores of PI (P <0.05) and PD ≥4 mm (P <0.05) were statistically significantly higher in smokers compared with non‐smokers in patients with IL and DL dental implants. The mean score of BOP (P <0.05) was statistically significantly higher in non‐smokers compared with smokers in both groups. CBL (P <0.05) was statistically significantly higher in smokers compared with non‐smokers in both groups. There was no statistically significant difference in PI, BOP, PD ≥4 mm, and total CBL among smokers with IL and DL implants. Conclusions: Tobacco smoking enhances peri‐implant soft tissue inflammation and CBL around IL and DL implants. Loading protocol did not show a significant effect on peri‐implant hard and soft tissue status in healthy smokers and non‐smokers.     

Evaluation of Clinical Outcomes and Bone Loss around Titanium Implants with Oxidized Surface: Six‐Year Follow‐Up Results from a Prospective Case Series Study

Purpose: The aim of this prospective study was to assess long‐term clinical outcomes and peri‐implant bone level changes around oxidized implants supporting partial fixed rehabilitations. Materials and Methods: Twenty‐two partially edentulous patients were included in the study. A total of 33 fixed rehabilitations were placed, supported by 54 titanium implants with oxidized microtextured surface. Prostheses were delivered after 3 and 6 months of implant placement in the mandible and maxilla, respectively. Patients were scheduled for follow‐up at 6 and 12 months and then yearly. At each follow‐up, plaque level and bleeding scores were assessed and periapical radiographs were taken. The main outcomes were prosthesis success, implant survival, implant success, and marginal bone level change. Results: Three patients were excluded from the study because they did not attend the 1‐year follow‐up. Nineteen patients, accounting for 49 implants, were followed for at least 6 years after prosthesis delivery. The mean follow‐up duration was 81.8 months (range 75–96 months). One mandibular single‐tooth implant failed after 1 year in a smoker woman. Cumulative implant survival and success at 6 years were 98.0% and 95.9%, respectively. Prosthesis success was 96.7%. The mean peri‐implant bone loss at 6 years was 0.76 ± 0.47 mm. Not significantly (p = .75) greater bone loss was found in the maxilla (0.78 ± 0.14 mm, n = 19) as compared with the mandible (0.74 ± 0.59 mm, n = 30). In the maxilla, bone loss was significantly greater around implants supporting partial prostheses as compared with single‐tooth implants (p = .03). Full patient satisfaction was reported. Conclusion: Implants with oxidized microtextured surface may achieve excellent long‐term clinical outcomes in the rehabilitation of partial edentulism.     

Implant Abutment Cleaning by Plasma of Argon: 5‐Year Follow‐Up of a Randomized Controlled Trial

Background: Contamination of implant abutments could potentially influence the peri‐implant tissue inflammatory response. The aim of the present study is to assess the radiographic bone changes around customized, platform‐switched abutments placed according to the “one‐abutment‐one‐time” protocol, with and without plasma of argon cleaning treatment. Methods: Thirty healthy patients with thin gingival biotype (<1 mm) and history of periodontal disease received one maxillary implant each. Immediately before abutment connection, patients were randomly assigned to control group (cleaning protocol by steaming) or test group (plasma of argon treatment). Outcome measures were: 1) success rate of implants and prostheses; 2) biologic and prosthetic complications; 3) peri‐implant marginal bone loss (MBL); 4) esthetic and periodontal parameters; and 5) patient satisfaction. Results: Neither implants nor prostheses were lost in either group at the 5‐year follow‐up examination. Overall, both groups showed a slight amount of peri‐implant bone loss from baseline to 5 years. A statistically higher mean MBL was found in the control group compared with the test group at 6, 24, and 60 months after crown connection. Nevertheless, during the entire follow‐up period, intragroup comparison demonstrated statistically significant mean MBL in the control group, but not in the test group. The test group showed a higher mean gain at the soft tissue margin, but not for the papilla. All implants showed good periodontal parameters, with no significant differences between groups. Conclusion: Plasma of argon could be used to disinfect implant abutments before insertion to minimize future peri‐implant bone resorption.