International Journal of Oral Implantology, 02/2010

Purpose: To assess the beneficial or harmful effects of systemic prophylactic antibiotics at dental implant placement versus no antibiotic/placebo administration and, if antibiotics are of benefit, to find which type, dosage and duration is the most effective. 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 2 June 2010 for randomised controlled clinical trials (RCTs) with a follow-up of at least 3 months comparing the administration of various prophylactic antibiotic regimens versus no antibiotics to patients undergoing dental implant placement. Outcome measures were prosthesis failures, implant failures, postoperative infections and adverse events (gastrointestinal, hypersensitivity, 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. Meta-analyses were conducted. Results: Four RCTs were identified: three comparing 2 g of preoperative amoxicillin versus placebo (927 patients) and the other comparing 1 g of preoperative amoxicillin plus 500 mg four times a day for 2 days versus no antibiotics (80 patients). The meta-analyses of the four trials showed a statistically significantly higher number of patients experiencing implant failures in the group not receiving antibiotics: risk ratio = 0.40 (95% confidence interval (CI) 0.19 to 0.84). The number needed to treat (NNT) to prevent one patient having an implant failure is 33 (95% CI 17-100), based on a patient implant failure rate of 5% in patients not receiving antibiotics. The other outcomes were not statistically significant, and only two minor adverse events were recorded, one in the placebo group. Conclusions: There is some evidence suggesting that 2 g of amoxicillin given orally 1 h preoperatively significantly reduce failures of dental implants placed in ordinary conditions. No significant adverse events were reported. It might be sensible to suggest the use of a single dose of 2 g prophylactic amoxicillin prior to dental implant placement. It is still unknown whether post-operative antibiotics are beneficial, and which is the most effective antibiotic. Keywords: antibiotics, dental implants, prophylaxis, randomised controlled clinical trial, systematic review Conflict-of-interest statement: Marco Esposito is the first author of two of the included studies; however, he was not involved in the quality assessment of these trials. This review is based on a Cochrane systematic review entitled 'Interventions for replacing missing teeth: antibiotics at dental implant placement to prevent complications' published in The Cochrane Library (see http://www.cochrane.org for more 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 whether immediate non-occlusal loading of single zirconia implants could reduce early failures when compared to immediate occlusal loading. Materials and methods: Forty partially edentulous patients who received one single zirconia implant (Z-Systems) at least 10 mm long and 3.25 mm wide inserted with a torque of at least 35 Ncm were randomised to immediate occlusal or non-occlusal loading groups. All patients received provisional acrylic crowns the same day of implant placement. Provisional crowns were replaced after 4 to 5 months by definitive full ceramic crowns. Outcome measures were implant success, any complications and peri-implant marginal bone levels. Results: One year after loading, no patients had dropped out. Five implants (12.5%) failed early: three occlusally loaded and two non-occlusally loaded. Three complications occurred, all after delivery of the definitive crowns: one crown fractured (occlusal loading), one had to be remade after debridement because of hyperplastic tissues (occlusal loading), and one crown decemented (nonocclusal loading). These differences were not statistically significant. Both groups gradually lost periimplant bone in a highly statistically significant way. One year after loading, patients subjected to non-occlusal loading lost an average of 0.7 mm of peri-implant bone versus 0.9 mm in the occlusal group. This difference in bone loss between groups was not statistically significant. There was an association between immediate post-extractive implants and implant failures (P = 0.01). Four of the 10 immediate post-extractive implants (40%) failed versus one out of 30 delayed implants (3%). Conclusions: The results of this study do not provide a conclusive answer to whether immediate non-occlusal loading may decrease implant failures. Immediately loaded zirconia implants placed in post-extractive sites had high failure rates. Keywords: immediate loading, non-occlusal loading, single implant, zirconia

Purpose: To investigate the effect of platelet-rich plasma (PRP) on the healing of hard and soft tissues of extraction sockets with a pilot study. Material and methods: Patients undergoing tooth extraction under intravenous sedation were asked to participate in the trial. Autologous platelet concentrates were prepared from the patients' blood and autologous thrombin was produced. Outcome measures were: pain level, analgesic consumption, oral function (ability to eat food, swallowing, mouth opening and speech), general activity, swelling, bruising, bleeding, bad taste or halitosis, food stagnation, patient satisfaction, healing complications, soft tissue healing, trabecular pattern of newly formed bone in extraction sockets, trabecular bone volume, trabecular separation, trabecular length, trabecular width, and trabecular number. Patients were followed up to 3 months post-extraction. Results: Twelve patients (15 sockets) were randomly allocated to the PRP group and 11 patients (14 sockets) to the control group. Two patients from the control group did not attend any of the scheduled appointments following tooth extraction, and were considered dropouts. Additionally, one more patient from the control group and four patients from the PRP group did not attend their 3-month radiographic assessment appointments. Statistically significantly more pain was recorded in the control group for the first (P = 0.02), second (P = 0.02) and third (P = 0.04) post-operative days for Visual Analogue Scale scores, whereas no differences were observed for the fourth (P = 0.17), fifth (P = 0.38), sixth (P = 0.75) and seventh (P = 0.75) post-operative days. There was a statistically significantly higher analgesic consumption for the first (P = 0.03) and second (P = 0.02) post-operative days in the control group and no differences thereafter. Differences in patients' responses in the health-related quality of life questionnaire were statistically significant in favour of PRP treatment only for the presence of bad taste or bad smell in the mouth (P = 0.03), and food stagnation in the operation area (P = 0.03). The difference between groups was not statistically significant for patient satisfaction with the treatment (P = 0.31). Regarding complications, two dry sockets and one acutely inflamed alveolus occurred in patients of the control group, which determined a borderline statistically significant difference in favour of the PRP group (P = 0.06). Soft tissue healing was significantly better in patients treated with PRP (P = 0.03). Radiographic evaluation carried out by the two blinded examiners revealed a statistically significant difference (P = 0.01) for sockets with dense homogeneous trabecular pattern, a borderline statistically significant difference in the trabecular pattern for bone volume (P = 0.06) favouring PRP use, and no significant differences for trabecular separation (P = 0.66), trabecular length (P = 0.16), trabecular width (P = 0.16) and trabecular number (P = 0.38). Conclusions: PRP may have some benefits in reducing complications such as alveolar osteitis and improving healing of soft tissue of extraction sockets. There were insufficient data to support the use of PRP to promote bone healing or to enhance the quality of life of patients following tooth extraction, although the sample size was too small to detect statistically significant differences. Keywords: extraction socket, healing, platelet-rich plasma, quality of life, radiographs

Purpose: To evaluate the efficacy of prophylactic antibiotics for dental implant placement. Materials and methods: Thirteen dentists working in private practices agreed to participate in this trial, each centre providing 50 patients. One hour prior to implant placement, patients were randomised to take orally 2 g amoxicillin or identical placebo tablets. Patients needing bone augmentation at implant placement were not included. Outcome measures were prosthesis and implant failures, adverse events and post-operative complications. Patients were seen 1 week, 2 weeks and 4 months post-operatively. Results: Two centres did not deliver any data, two centres did not manage to include the agreed quota of patients and three patients had to be excluded. Two-hundred and fifty-two patients were evaluated in the antibiotic group and 254 in the placebo group, and none dropped out at 4 months. Four prostheses and seven implants (in five patients) failed in the antibiotics group versus 10 prostheses and 13 implants (in 12 patients) in the placebo group. Eleven complications were reported in the antibiotic group versus 13 (in 12 patients) in the placebo group. No side effects were reported. There were no statistically significant differences for prosthesis failures, implant losses and complications. Patients receiving immediate post-extractive implants had an increased failure risk compared with patients receiving delayed implants (9% versus 2%). Conclusions: No statistically significant differences were observed, although trends clearly favoured the antibiotic group. Immediate post-extractive implants were more likely to fail. Keywords: amoxicillin, antibiotic prophylaxis, dental implants, immediate post-extractive implants, multicentre randomised placebo-controlled clinical trial

Aim: The aim of this study was to evaluate differences in the inflammatory profile of young (=40 years) systemically healthy periodontal patients comparing chronic (CP) versus aggressive periodontitis (AP) in terms of cytokines, chemokines and C-reactive protein levels. Methods: Systemically healthy subjects affected by severe CP or AP were enrolled in this study. Differential diagnosis was performed according to the criteria suggested by the American Academy of Periodontology. Blood samples for the evaluation of high sensitivity C-reactive protein levels, cytokine levels (IL-1ß, IL-1RA, IL-4, IL-6, IL-10, IL-12, interferon-γ, interferon-γ-inducible protein 10, tumour necrosis factor α) and chemokine levels (IL-8, vascular endothelial growth factor, monocyte chemoattractant protein 1, macrophage inflammatory protein 1α and macrophage inflammatory protein 1ß) were obtained from all patients. Results: A total of 45 systemically healthy patients with severe periodontitis were consecutively selected, 21 with CP (mean age 36.8 ± 3.5; mean clinical attachment level [CAL] 4.72 ± 0.69) and 24 with AP (mean age 35.9 ± 3.8; mean CAL 4.68 ± 0.75). No statistically significant difference between the two groups was detected for periodontal variables and for all the investigated inflammatory markers. Conclusions: The inflammatory profile of severe periodontitis in young patients (=40 years) may be similar for chronic and aggressive types. Differential diagnosis between CP and AP may not be able to detect a different systemic inflammatory profile in young adults. Keywords: aggressive periodontitis, chemokines, chronic periodontitis, cytokines, host response, systemic inflammation

Purpose: To report the outcome of an implant therapy protocol using 4 or 6 implants supporting immediately loaded fixed prostheses following 3D software planning and flapless guided surgery. Materials and methods: A total of 30 patients (24 women, 6 men), mean age of 53 years (range 35-84 years) were treated with 195 immediately loaded implants (97 NobelSpeedy Groovy and 98 Brånemark MKIII Groovy) supporting 25 maxillary and 17 mandibular fixed full-arch acrylic prostheses and followed for 1 year. The Procera Software v1.6 and v2.0 was used to plan implant position and to obtain a surgical template for the guided flapless implant placement. To perform immediate loading, the implants had to be inserted with torque of at least 35 Ncm. Provisional prostheses were made before surgery using software planning and were placed in the same session as the implants. Definitive restorations were delivered 6-12 months after surgery. Outcome measures were failures of the prosthesis and of the implants, marginal bone level changes, complications, clinical time and patient satisfaction. Results: Four patients with full edentulism and 26 with advanced periodontitis were enrolled in this study. A total of 195 implants were immediately loaded (128 implants were placed in the maxilla and 67 implants were placed in the mandible). Four implants out of 195 failed in three patients during the healing period: 2 in the maxilla (1 straight and 1 tilted), and 2 in the mandible (both of them tilted). Three of them were successfully replaced. One year after loading there were no dropouts and no failure of the definitive prosthesis occurred. In three cases, the surgical template fractured during surgery. In one patient, a new impression had to be taken to fit the provisional prosthesis onto the implants. Three patients were subjected to surgery and systemic antibiotics to treat apically infected implants. Conclusions: The 'all-on-four' and 'all-on-six' treatment protocol combined with computer-guided flapless implant surgery could be a viable and predictable treatment. Some complications occurred that were successfully treated. However, this technique could be sensitive to the experience of the surgeon and a learning curve is required. Keywords: computerised tomographic scan, flapless surgery, full edentulism, guided surgery, immediate loading