International Journal of Oral Implantology, 02/2020

Aims: To evaluate whether piezoelectric bone surgery (PBS) for lateral maxillary sinus floor elevation reduces risk of intraoperative complications, requires prolonged surgical time and improves the survival rate of dental implants in comparison with conventional rotary instruments. Materials and methods: This meta-analysis followed PRISMA guidelines and was registered in the PROSPERO database (CRD42019122972). The PubMed, Embase, Scopus and Open Grey databases were screened for articles published from 1 January 1990 to 31 December 2018. The selection criteria included randomised controlled trials (RCTs) and case-control studies (CCTs) comparing PBS with rotary instruments in lateral sinus augmentation and reporting intraoperative and postoperative outcomes (e.g. sinus membrane perforations, surgical time and implant failure rate). The risk of bias assessment was performed using the Cochrane Collaboration's tool for RCTs. A meta-analysis was performed, and the power of the meta-analytic findings was assessed via trial sequential analysis (TSA). Results: Four RCTs met the inclusion criteria and were included in the review. The meta-analysis showed that, although a lower incidence of membrane tearing occurred when using PBS, the difference between the two groups was not significant. However, the power of evidence for this outcome, as determined by the TSA, was weak. Moreover, there was moderate evidence suggesting that PBS prolongs the surgery duration (mean difference of 3.43 minutes), whilst insufficient data was present to assess if PBS improves the survival rate of implants inserted in augmented sinuses. Conclusions: The power of the evidence was too weak to confirm the above-mentioned findings and further well-designed randomised clinical trials are needed to draw definitive conclusions. Keywords: intraoperative complications, membrane perforation, piezosurgery, sinus floor elevation Conflict-of-interest statement: The authors report no conflicts of interest related to this study. This study received no external funding.

Purpose: To assess the effectiveness of different nonsurgical protocols for the treatment of peri-implant mucositis. Materials and methods: The identification of randomised clinical trials (RCTs) was systematically performed in three databases and supplemented by a thorough manual search of the literature in periodontics/implantology-related journals. Studies investigating the effect of mechanical and/or chemical plaque control agents aimed at preventing the development of peri-implant mucositis were excluded. When comparable trials were found, a meta-analysis was performed. Results: Fourteen studies were included in the systematic review and three in the meta-analysis. None of the selected studies reported a complete resolution of the peri-implant mucositis lesions. A nonsurgical therapy alone showed an average reduction of: 0.57 mm (95% CI [0.30 to 0.83]) in probing pocket depth (PPD); 22.41% (95% CI [12.74 to 32.08]) in bleeding on probing (BOP); 17.28% (95% CI [3.99 to 30.58]) in the plaque index (PI); and 13.41% (95% CI [3.50 to 23.31]) in the bleeding index (BI). The meta-analysis failed to demonstrate significant improvements with the adjunct use of chlorhexidine disinfectant to nonsurgical mechanical debridement for PPD reduction (–0.07 mm; 95% CI [–0.33 to 1.15], P = 0.62), and relative attachment level (RAL) gain (–0.13 mm; 95% CI [–0.6 to 0.35]), P = 0.6). Conclusion: Conventional nonsurgical mechanical therapy alone may be considered the standard treatment for peri-implant mucositis as there is still a lack of evidence supporting the use of additional chemical/mechanical agents for clinical and/or microbiological improvement. Keywords: chlorhexidine, dental implants, mechanical therapy, nonsurgical treatment, probiotics, triclosan Conflict-of-interest statement: The authors declare no financial interest, either directly or indirectly, in the products or information listed in the manuscript. The work was partially supported by the University of Michigan Periodontal Graduate Student Research Fund.

Purpose: To evaluate whether the use of piezoelectric bone surgery (PBS) for implant site preparation reduces surgical time, improves implant stability, preserves marginal bone level and improves the survival rate of oral implants compared with conventional drilling techniques. Materials and methods: This meta-analysis followed the PRISMA (preferred reporting items for systematic review and meta-analysis) guidelines and was registered in the PROSPERO (international prospective register of systematic reviews) database (CRD42019142749). The PubMed, Embase, Scopus and Open Grey databases were screened for articles published from 1 January 1990 to 31 December 2018. The selection criteria included randomised controlled trials (RCTs) and case-control studies (CCTs) comparing the PBS with conventional rotary instruments for implant site preparation, and reporting any of the selected clinical outcomes (surgical time, implant stability, marginal bone variations and implant failure rate) for both groups. The risk of bias assessment was performed using the Cochrane Collaboration tool for RCTs and the Newcastle-Ottawa scale (NOS) for CCTs. A meta-analysis was performed, and the power of the meta-analytic findings was assessed by trial sequential analysis (TSA). Results: Eight RCTs and one CCT met the inclusion criteria and were included in the review. The meta-analysis and the TSA showed moderate evidence suggesting that the PBS prolongs surgery duration and improves secondary stability 12 weeks after implant placement compared with conventional drilling techniques. Insufficient data are available in literature to assess if the PBS reduces marginal bone loss and/or improves the implant survival rate compared with conventional drilling techniques. Conclusions: Adequately powered randomised clinical trials are needed to confirm the PBS positive effect on the secondary stability and to draw conclusions about the influence of PBS on marginal bone stability and implant survival. Keywords: implant site preparation, implant stability, piezosurgery, trial sequential analysis Conflict-of-interest statement: The authors report no conflicts of interest related to this study. The present study received no external funding.

Purpose: To describe implant survival at least 1 year after the surgical treatment of early apical peri-implantitis (EAP) and explore potential risk factors of failure of such treatment. Materials and methods: An ambispective cohort study was conducted, involving all patients in whom EAP was detected and surgically treated between 1996 and 2016. Reporting followed the STROBE guidelines. The time from implant placement (IP) to EAP surgery (EAPS), the diagnostic stage and intraoperative variables (location, apical lesion in the tooth being replaced, mesial and distal tooth-implant distance measured at the apex, periapical surgery of the adjacent tooth, guided bone regeneration, implant resection, explantation) were recorded to determine their impact upon treatment outcome. Results: The initial sample consisted of 58 implants in 46 patients. The mean time from IP to EAPS was 21.7 ± 10.1 days. At the time of surgery, eight implants presented mobility and were explanted. The final sample consisted of 50 implants in 39 patients evaluated for implant survival after surgical treatment. A cumulative survival rate of 78.3% was recorded. The mean survival time of the EAP treated implants was 85.4 months (standard deviation [SD] 5.94). The diagnostic stage (P 0.001) and the existence of a previous periapical lesion in the tooth being replaced (P = 0.022) had a significant influence upon implant survival. Conclusions: The cumulative survival rate was 78.3%, with a mean survival time of 85.4 months. The diagnostic stage of EAP and the presence of a lesion in the tooth being replaced significantly influenced the survival of implants with EAP subjected to surgical treatment. Keywords: early peri-implantitis, follow-up, implant failure, implant periapical lesion, retrograde peri-implantitis, treatment survival Conflict-of-interest statement: The authors declare no conflicts of interest related to this study. *First and second authors claim equal authorship.

Purpose: This long-term cohort study investigated the prevalence of mucositis, peri-implantitis, bone loss and survival of turned surface implants in partially edentulous patients treated for periodontitis. Materials and methods: 19 patients treated for generalised chronic periodontitis (GCP) and 20 patients treated for generalised aggressive periodontitis (GAP) were orally rehabilitated with a total of 126 dental implants. Examinations were performed before implant insertion, at the time of superstructure insertion, and in the subsequent years during a 3-month recall schedule over a 10- to 20-year period. At every session, clinical parameters were recorded. Intraoral radiographs were taken after insertion of superstructures and 1, 3, 5, 10, 15 and 20 years later. Results: In total, nine implants were lost during the 20-year observation period. The implant survival rate was 92.1% (GCP patients) and 90.1% (GAP patients). After 10 years, mucositis was present in 21.9% and 21.2% of implants in GCP and GAP patients, respectively. The risk of mucositis was significantly lower in patients with a removable superstructure (OR = 0.061 with P = 0.001). Peri-implantitis was present in 12.2% implants (GCP patients) and 14.1% implants (GAP patients). Implants inserted in bone quality grade 3 showed a significantly higher risk of peri-implantitis (OR = 5.658 with P = 0.003). After 10 years, implants in GAP patients did not show a significant higher bone loss (1.87 ± 1.40 mm) compared with implants in GCP patients (1.50 ± 1.30 mm). After 20 years, the total mean peri-implant bone loss was 1.98 ± 1.64 mm, almost every fifth implant revealed a bone loss > 3 mm. Conclusions: The implant survival rate in both patient groups was > 90%, and implants showed a moderate mucositis ( 30%) and peri-implantitis ( 25%) rate. Bone quality and type of superstructure seem to have had an influence on peri-implant health. These results suggest that patients with a history of periodontitis treated in a tight recall schedule can be successfully rehabilitated with turned surface implants for a follow-up period of 10 to 20 years. Keywords: bone loss, long-term cohort study, mucositis, patients with periodontitis, peri-implantitis, survival, turned surface implants Conflict-of-interest statement: The authors declare that they have no conflicts of interest.