International Journal of Oral Implantology, 03/2010

This review is based on a Cochrane systematic review entitled 'Interventions for replacing missing teeth: dental implants in fresh extraction sockets (immediate, immediate-delayed and delayed implants)' published in The Cochrane Library (see http://www.cochrane.org/ for information). Cochrane systematic reviews are regularly updated to include new research, and in response to comments and criticisms from readers. If you wish to comment on this review, please send your comments to the Cochrane website or to Marco Esposito. The Cochrane Library should be consulted for the most recent version of the review. The results of a Cochrane review can be interpreted differently, depending on people's perspectives and circumstances. Please consider the conclusions presented carefully. They are the opinions of the review authors, and are not necessarily shared by the Cochrane Collaboration. Purpose: To evaluate success, complications, aesthetics and patient satisfaction among immediate, immediate-delayed and delayed implants in post-extractive sockets and whether and when augmentation procedures are necessary and which is the most effective augmentation technique. Materials and methods: The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched up to the 2nd of June 2010 for randomised controlled clinical trials (RCTs) with a follow-up of at least 1 year in function comparing immediate, immediate-delayed and delayed implants, or comparing various bone augmentation procedures around the inserted implants. Outcome measures were prosthesis and implant failures, complications, patient satisfaction and preference including aesthetics, aesthetics evaluated by a dentist, peri-implant marginal bone level changes, etc. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. The statistical unit of the analysis was the patient. Results were expressed as fixed effects models using mean differences for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CIs). Results: Fourteen eligible RCTs were identified but only seven trials could be included. Four RCTs evaluated implant placement timing. Two RCTs compared immediate versus delayed implants in 126 patients and found no statistically significant differences. One RCT compared immediate-delayed versus delayed implants in 46 patients. After 2 years, patients in the immediate-delayed group perceived the time to functional loading significantly shorter, were more satisfied and an independent blinded assessor judged the level of the peri-implant marginal mucosa in relation to that of the adjacent teeth as more appropriate (RR = 1.68; 95% CI 1.04 to 2.72). These differences disappeared 5 years after loading, and significantly more complications occurred in the immediatedelayed group (RR = 4.20; 95% CI 1.01 to 17.43). One RCT compared immediate with immediately delayed implants in 16 patients for 2 years and found no differences. Three RCTs evaluated different techniques of bone grafting for implants immediately placed in extraction sockets. No statistically significant differences were observed when evaluating whether autogenous bone is needed in postextractive sites (one trial with 26 patients) or which was the most effective augmentation technique (two trials with 56 patients). Conclusions: There is insufficient evidence to determine the possible advantages or disadvantages of immediate, immediate-delayed or delayed implants, therefore these preliminary conclusions are based on few underpowered trials often judged to be at high risk of bias. There is a suggestion that immediate and immediate-delayed implants may be at a higher risk of implant failure and complications than delayed implants, on the other hand the aesthetic outcome might be better when placing implants just after tooth extraction. There is not enough reliable evidence supporting or refuting the need for augmentation procedures at immediate implants placed in fresh extraction sockets or whether any of the augmentation techniques is superior to the others. Keywords: dental implants, post-extractive implants, randomised controlled clinical trial, systematic review Conflict-of-interest statement: None declared.

Purpose: To compare peri-implant bone and soft-tissue levels of immediately non-occlusally loaded versus non-submerged early loaded implants in partially edentulous patients 5 years after implant placement. Materials and methods: Fifty-two patients were randomised in five Italian private practices: 25 in the immediately loaded group and 27 in the early loaded group. To be immediately loaded, single implants had to be inserted with a torque of > 30 Ncm, and splinted implants with a torque of > 20 Ncm. Immediately loaded implants were provided with non-occluding temporary restorations within 48 hours. After 2 months, the provisional restorations were put in full occlusion. Implants were early loaded after 2 months. Final restorations were provided 8 months after implant placement. Outcome measures were prosthesis and implant failures as well as biological and prosthetic complications recorded by non-blinded assessors. Blinded assessors evaluated peri-implant bone and soft-tissue levels. Results: Fifty-two implants were immediately loaded and 52 early loaded. One patient of the early loaded group dropped out after the 1-year recall. One single immediately loaded implant failed 2 months after placement. Only one complication (iatrogenic peri-implantitis) occurred in one patient of the early loading group. Both groups gradually lost peri-implant bone in a highly statistically significant way at 2, 8 and 14 months and at 4 and 5 years. After 5 years, patients of both groups had lost an average of 1.2 mm of peri-implant marginal bone. There were no statistically significant differences in peri-implant bone and soft-tissue level changes between the 2 groups. At 5 years, there was a statistically significant recession (0.2 mm) of the vestibular soft tissues from baseline (delivery of the final restorations 8 months after implant placement) only for immediately loaded implants. Conclusions: In well maintained patients, complications are uncommon and healthy and stable periimplant tissues can be maintained for 5 years around immediately and early loaded implants. Keywords: dental implants, early loading, follow-up, immediate loading, partial edentulism Conflict-of-interest statement: This trial was independently designed and initiated by the investigators, however BIOMET 3i provided partial economic support at a later stage.

Purpose: To compare the effectiveness of two different techniques to lift the maxillary sinus via a crestal approach: the Summers versus the Cosci technique. Materials and methods: Fifteen partially edentulous patients missing bilaterally maxillary molars and/ or premolars having 4 to 7 mm of residual crestal height and at least 5 mm thickness below the maxillary sinuses measured on computed tomography scans were randomised to have implants placed in sinuses crestally lifted according to the Cosci or Summers technique with bone substitutes according to a split-mouth design. Implants were left to heal submerged for 6 months. Implants were loaded with acrylic provisional crowns/prostheses. Screw-retained definitive metal-ceramic prostheses were delivered 4 months after provisional loading. Outcome measures were prosthesis and implant failures, any complications, operation time, operator preference, and patient preference assessed 1 month after surgery and 1 month after delivery of the final prostheses by a blinded outcome assessor. All patients were followed up to 5 months after loading (1 year after implant placement). Results: Nineteen study implants were placed according to each technique. No patient dropped out and no implant failed. No discomfort/complications occurred at sites treated with the Cosci technique whereas 12 patients reported discomfort during the augmentation procedure at the side treated with the Summers technique, this was statistically significant, and in one of these patients a perforation of the sinus membrane occurred. Postoperatively, headache was reported by nine patients and swelling occurred in three of these patients at the Summers treated sides. Statistically significantly less time was required to place implants according to the Cosci technique (33 versus 24 minutes, on average). The two operators and 14 out of 15 patients preferred the Cosci technique. Conclusions: Both crestal sinus lift techniques were successful but the Cosci technique required less surgical time, produced less intra- and postoperative morbidity and was preferred by patients. Keywords: bone augmentation, crestal sinus lift, patient morbidity, patient preference, surgical techniques Conflict-of-interest statement: This was an investigator initiated trial, however the trial was partially supported by Zimmer Dental, Vittorio Veneto (TV), Italy. One of the authors (Dr Cosci) who treated eight patients in this study is the inventor of the Cosci technique and was a prerequisite of the sponsor to support the trial.

Purpose: The aim of this randomised, controlled, parallel-group clinical trial was to evaluate the clinical effect of platelet-rich plasma (PRP) on bone graft healing and implant integration in iliac crest grafted maxillae. Materials and methods: Twenty-two consenting patients were randomised to PRP (13 patients) and control (9 patients) groups. Both groups received onlays and 16 patients had their maxillary sinus grafted with particulate bone (lateral window approach) with iliac crest bone grafts. Autologous platelet concentrates were prepared from the patients' blood and autologous thrombin was produced. PRP was mixed with the test group bone grafts. Outcome measures were implant integration, implant stability, soft tissue healing, graft resorption, and donor and recipient site complications. Implant stability measurements were recorded at placement and exposure using a resonance frequency analysis device. Patients were followed up to abutment connection. Multiple linear regression analyses using robust standard error were performed, taking the patient as the unit of measurement. The t test was also used where appropriate. Results: One bone graft failed in the PRP group and regrafting was required. No statistically significant differences were observed for soft tissue healing indices (P = 0.4) and mean graft resorption (P = 0.5) between groups. All implants were found clinically integrated at time of exposure. No statistically significant differences in implant stability were observed between groups at implant placement (P = 0.059) and exposure (P = 0.1). Using a post-hoc analysis, posterior implants in the PRP group showed statistically significantly higher stability values (61 ± 2.6) than anterior implants (60 ± 2.4) at implant placement (mean difference -0.95, P = 0.04). However, this difference was not clinically significant. Conclusion: No appreciable clinical effect could be observed when using PRP with autologous iliac crest bone graft in the maxilla. Keywords: bone graft, iliac crest, implant stability, maxilla, platelet-rich plasma Conflict-of-interest statement: There is no financial conflict of interest.

Aims: To evaluate the clinical outcome of fully edentulous patients in the maxilla, who were treated with immediately loaded implant-supported cross-arch bridges using computer-aided implant surgery. Materials and methods: The clinical outcome of 15 consecutive patients (5 males and 10 females) with a mean age of 52 years (range 40 to 70), with edentulous arches and treated with implantsupported cross-arch bridges was evaluated. Two computed tomography scans were performed, the first with the patient wearing the denture/radiographic guide and the radiographic index, and the second of the denture alone. The guided flapless surgical procedure was performed under local anaesthesia. Ninety implants were placed. The implant length ranged from 10 to 13 mm and the implant diameter was either 4.3 or 5 mm. All implants were immediately loaded with screw-retained provisional acrylic prostheses prepared in advance and delivered immediately after surgery. Clinical and radiographic follow-up visits were scheduled at 6, 12 and 18 months from surgery; implant survival rate, marginal bone levels, patient satisfaction and any complications were recorded. Results: After the follow-up period of 18 months, two patients each lost one implant. After 18 months, patients lost, on average, 1.6 mm of peri-implant marginal bone. A patient satisfaction questionnaire at 18 months revealed a very high level of satisfaction with the treatment. Conclusion: Although limited by the number of patients, it can be concluded that software- and computed tomography-guided surgical planning for completely edentulous arches provides reliable results with high success rates. Keywords: computed tomography-guided implant surgery, immediate loading, software planning

Purpose: The purpose of the present case report was to document a maxillary sinus floor augmentation procedure involving ligation of a blood vessel with a nearly 3-mm diameter in the lateral wall of the maxillary sinus. Materials and methods: A bilateral maxillary sinus floor augmentation procedure was performed in a 51-year-old healthy man. The preoperative computed tomography scan revealed a bony canal within the lateral maxillary sinus wall of the right as well as the left side close to the alveolar ridge. Results: A vessel with a diameter of nearly 3 mm was identified during the sinus floor augmentation on the left side. The vessel was exposed and ligated. A vessel with a diameter of approximately 1 mm was identified on the right side and the sinus floor augmentation was performed without ligation. No complications were observed and the postoperative healing was uneventful. Conclusions: Although accidental laceration of vessels with an unusually large diameter during maxillary sinus floor augmentation is not life-threatening, impaired visualisation may compromise the augmentation procedure, including the elevation of the Schneiderian membrane. Moreover, postoperative bleeding and formation of a haematoma may occur. Therefore, ligation of vessels with an unusually large diameter is recommended during maxillary sinus floor augmentation to minimise intra- and postoperative complications. Keywords: alveolar ridge augmentation, complications, dental implants, maxillary sinus, oral implants, sinus floor augmentation, vascularisation Conflict-of-interest statement: The authors state that they do not have any financial or personal relationships with people or organisations that could inappropriately influence the present paper.