Short (≤6 mm) compared with ≥10-mm dental implants in different clinical scenarios: A systematic review of randomized clinical trials with meta-analysis, trial sequential analysis and quality of evidence grading.

AIM: To systematically identify, synthesize and critically summarize the available scientific evidence from randomized controlled trials (RCTs) regarding whether short (≤6 mm) perform as well as long (≥10 mm) implants regarding implant survival, marginal bone loss, and biologic and prosthetic complications in different clinical scenarios. MATERIALS AND METHODS: Cochrane Collaboration's risk of bias tool and the GRADE approach were applied. Results were synthesized using random-effects meta-analyses assessed by trial sequential analyses. RESULTS: Forty reports on 19 RCTs comprising 2214 (1097 short; 1117 long) implants were included. Moderate/high certainty/quality evidence demonstrated similar 5-year survival rates for ≤6-mm and ≥10-mm implants in non-augmented bone and full-mouth rehabilitation in either jaw, and for 6-mm implants in the maxilla instead of sinus lift. Nevertheless, the evidence for 5-year survival rates remains inconclusive or insufficient for the remaining combinations of implant lengths and clinical scenarios. They include 4-mm and 5-mm implants as alternatives to sinus lift as well as placing all implant lengths ≤6 mm instead of vertical ridge augmentation with long implants. Marginal bone level and short- and long-term biologic or prosthetic complications were similar. CONCLUSIONS: Based on moderate/high certainty/quality evidence from 5-year RCTs, implants ≤6 mm may be viable alternatives to ≥10-mm implants in either jaw in native bone and full-arch rehabilitation, and 6-mm implants may be used as an alternative to sinus lift. TRIAL REGISTRATION: PROSPERO ID: CRD42021254365.

Short versus Longer Implants in Sites without the Need for Bone Augmentation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: The present systematic review and meta-analysis aims to analyse the clinical performance of short compared to longer implants inserted in sites without the need for bone augmentation. METHODS: The protocol of the present PRISMA-driven meta-analysis was registered on PROSPERO (CRD42021264781). Electronic and manual searches were performed up to January 2022. All Randomized Controlled Trials (RCTs) comparing short (≤6 mm) to longer (≥8.5 mm) implants placed in non-atrophic and non-augmented sites were included. The quality of the included studies was assessed using the Cochrane risk of bias tool for randomized clinical trials (RoB 2) and the quality of evidence was determined with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. A meta-analysis was performed on implant survival rate, marginal bone level change (MBLc), and technical and biological complications at the available follow-up time points. The power of the meta-analytic findings was determined by trial sequential analysis (TSA). RESULTS: From 1485 initial records, 13 articles were finally included. No significant difference was found in the survival rate between short and long implant at any follow-up (moderate quality of evidence). Significantly more bone loss for long implants at 1 and 5 years from implant placement and more technical complications with short implants at 10 years were found. No other significant inter-group differences in terms of MBLc and biological complications were detected. CONCLUSIONS: Moderate evidence exists suggesting that short implants perform as well as longer ones in the rehabilitation of edentulous sites without the need for bone augmentation. Further long-term, well-designed RCTs, however, are still needed to provide specific evidence-based clinical recommendations for an extended use of short implants in non-atrophic sites.

A Systematic Critical Appraisal of the Methodological Quality of Systematic Reviews on the Effect of Autologous Platelet Concentrates in the Treatment of Periodontal Intraosseous Defects.

The present study aimed to perform a systematic critical appraisal of the methodological quality of systematic reviews (SRs) on the effect of autologous platelet concentrates (APCs) in the treatment of periodontal intraosseous defects and to provide a synthesis of the main clinical findings available. An electronic and hand search was performed up to February 2020; 14 systematic reviews of randomized controlled trials (RCTs), of which 11 were meta-analyses, were included. Only one SR fully satisfied all 11 items of the AMSTAR ("A Measurement Tool to Assess Systematic Reviews") checklist for methodological quality evaluation, 3 SRs were classified of high quality, 8 of medium quality, and 2 of low quality. There is some evidence on the beneficial additive effect of APCs in the surgical treatment of intraosseous defects when used alone or in combination with bone grafts. APCs did not show any advantage when used together with guided tissue regeneration (GTR) or enamel matrix derivative (EMD). Undertaking SRs which adhere to rigorous standards and protocols is strongly recommended. There are increasing data on the positive adjunctive effect of APCs in the surgical treatment of intraosseous defects but, due to the heterogeneity of the available primary studies, the quality of evidence remains rather low and further long-term well-designed RCTs are encouraged.

Periodontitis, Low-Grade Inflammation and Systemic Health: A Scoping Review.

Background and objectives: Periodontitis is a multifactorial chronic inflammatory infectious disease in which an infection is necessary, but not sufficient, for development of the condition. Individual susceptibility strictly linked to the immune and inflammatory response of the organism must also be present. Low-grade inflammation (LGI) is a systemic status of chronic sub-clinical production of inflammatory factors. This condition represents a risk factor for many chronic diseases including diabetes, cardiovascular disease, cerebrovascular disease, neurodegenerative disease and cancer. This scoping review aims to clarify, summarize and disseminate current knowledge on the possible link between periodontitis, LGI and systemic health. Materials and Methods: PRISMA Extension for Scoping Reviews guidelines were followed. An ad-hoc created keyword string was used to search the electronic databases of PubMed/Medline, Embase, The Cochrane Library and ClinicalTrials.gov. A hand search of specialized journals and their reference lists was also performed. Results: 14 studies that respected eligibility criteria were selected and analyzed. There is emerging evidence of strong links between periodontitis, LGI and systemic health. On the one hand, periodontitis influences the systemic status of LGI and on the other hand, the systemic production of inflammatory factors affects periodontitis with a bidirectional connection. Conclusions: LGI and the subsequent onset of a systemic inflammatory phenotype can be considered the common substrate of many chronic inflammatory diseases including periodontitis, with multiple mutual connections between them. Understanding of the biological principles and mechanisms underlying such a complex interrelationship could lead to significant improvements in the field of personalized diagnostics and therapeutic protocols.

Do Dietary Supplements and Nutraceuticals Have Effects on Dental Implant Osseointegration? A Scoping Review.

Several factors affect dental implant osseointegration, including surgical issues, bone quality and quantity, and host-related factors, such as patients' nutritional status. Many micronutrients might play a key role in dental implant osseointegration by influencing some alveolar bone parameters, such as healing of the alveolus after tooth extraction. This scoping review aims to summarize the role of dietary supplements in optimizing osseointegration after implant insertion surgery. A technical expert panel (TEP) of 11 medical specialists with expertise in oral surgery, bone metabolism, nutrition, and orthopedic surgery performed the review following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) model. The TEP identified micronutrients from the "European Union (EU) Register of nutrition and health claims made on foods" that have a relationship with bone and tooth health, and planned a PubMed search, selecting micronutrients previously identified as MeSH (Medical Subject Headings) terms and adding to each of them the words "dental implants" and "osseointegration". The TEP identified 19 studies concerning vitamin D, magnesium, resveratrol, vitamin C, a mixture of calcium, magnesium, zinc, and vitamin D, and synthetic bone mineral. However, several micronutrients are non-authorized by the "EU Register on nutrition and health claims" for improving bone and/or tooth health. Our scoping review suggests a limited role of nutraceuticals in promoting osseointegration of dental implants, although, in some cases, such as for vitamin D deficiency, there is a clear link among their deficit, reduced osseointegration, and early implant failure, thus requiring an adequate supplementation.

Enamel Matrix Derivative and Autogenous Bone Graft for Periodontal Regeneration of Intrabony Defects in Humans: A Systematic Review and Meta-Analysis.

The combination of enamel matrix derivative (EMD) with an autogenous bone graft in periodontal regeneration has been proposed to improve clinical outcomes, especially in case of deep non-contained periodontal defects, with variable results. The aim of the present systematic review and meta-analysis was to assess the efficacy of EMD in combination with autogenous bone graft compared with the use of EMD alone for the regeneration of periodontal intrabony defects. A literature search in PubMed and in the Cochrane Central Register of Controlled Trials was carried out on February 2019 using an ad-hoc search string created by two independent and calibrated reviewers. All randomized controlled trials (RCTs) comparing a combination of EMD and autogenous bone graft with EMD alone for the treatment of periodontal intrabony defects were included. Studies involving other graft materials were excluded. The requested follow-up was at least 6 months. There was no restriction on age or number of patients. Standard difference in means between test and control groups as well as relative forest plots were calculated for clinical attachment level gain (CALgain), probing depth reduction (PDred), and gingival recession increase (RECinc). Three RCTs reporting on 79 patients and 98 intrabony defects were selected for the analysis. Statistical heterogeneity was detected as significantly high in the analysis of PDred and RECinc (I2 = 85.28%, p = 0.001; I2 = 73.95%, p = 0.022, respectively), but not in the analysis of CALgain (I2 = 59.30%, p = 0.086). Standard difference in means (SDM) for CALgain between test and control groups amounted to -0.34 mm (95% CI -0.77 to 0.09; p = 0.12). SDM for PDred amounted to -0.43 mm (95% CI -0.86 to 0.01; p = 0.06). SDM for RECinc amounted to 0.12 mm (95% CI -0.30 to 0.55. p = 0.57). Within their limits, the obtained results indicate that the combination of enamel matrix derivative and autogenous bone graft may result in non-significant additional clinical improvements in terms of CALgain, PDred, and RECinc compared with those obtained with EMD alone. Several factors, including the surgical protocol used (e.g. supracrestal soft tissue preservation techniques) could have masked the potential additional benefit of the combined approach. Further well-designed randomized controlled trials, with well-defined selection criteria and operative protocols, are needed to draw more definite conclusions.

The Use of Poly-d,l-lactic Acid (PDLLA) Devices for Bone Augmentation Techniques: A Systematic Review.

Poly-d,l-lactic acid (PDLLA) has been proposed in dentistry for regenerative procedures in the form of membranes, screws, and pins. The aim of this review was to evaluate the efficacy of bone augmentation techniques using PDLLA devices. A literature search was carried out by two independent and calibrated reviewers. All interventional and observational studies assessing the efficacy of bone augmentation techniques using PDLLA devices were included. Six studies were included. The relevant variability of design and methods impeded any qualitative or quantitative comparison. Ease of handling, absence of a re-entry phase, moldability of foils, and good soft-tissue response were appreciated characteristics of PDLLA devices. Some drawbacks such as the risk of membrane exposition, a prolonged adsorbability, and a tendency to a fibrous encapsulation of the PDLLA devices have been described, although the clinical significance of these findings is unclear. Clinical data about PDLLA devices for bone regeneration are very scarce and heterogenous. Well-designed randomized controlled trials comparing the use of PDLLA foils and pins with conventional membranes for bone regeneration are strongly encouraged in order to understand the real clinical benefits/drawbacks of this technique.