Immediate implant placement in molar regions: risk factors for early failure

Learn, unlearn, and relearn post-extraction alveolar socket healing: Evolving knowledge and practices

OBJECTIVE

This review was to offer a comprehensive analysis of currently available evidence on post-extraction alveolar socket healing, including i) the histological and molecular events during alveolar socket healing, ii) the dimensional ridge alterations after socket healing and controversies relating to sinus pneumatisation, iii) the patient-specific factors, procedural elements, and site-related variables influencing socket healing, iv) techniques and effectiveness of alveolar ridge preservation (ARP) procedure, and v) the philosophies and cost-effectiveness of ARP in clinical practice.

SOURCES AND STUDY SELECTION

To investigate the dimensional profiles of the alveolar ridge following unassisted healing, an overview of systematic reviews was conducted in February 2024 by two independent reviewers. Four electronic databases were searched in Pubmed, Embase, Web of science and Cochrane Library between 2004 and 2024 to identify all relevant systematic reviews on post-extraction healing. A further manual search of reviews was also conducted. The articles were further reviewed in full text for relevance. The AMSTAR-2 appraisal tool was adopted to assess methodological quality. Current research pertaining to other listed objectives was objectively analysed in narration.

DATA

11 out of 459 retrieved studies were selected and ultimately covered in this review on the dimensional changes of alveolar ridge following natural healing: Seven systematic reviews and four systematic reviews with meta-analyses. The methodological quality of all included reviews was critically low.

CONCLUSION

This review thoroughly examines the healing profiles of post-extraction alveolar sockets and highlights the dynamic process with overlapping phases and the inter-individual variability in outcomes. ARP procedure is a potential strategy for facilitating prosthetic site development, while the current evidence is limited. Herein, an individualised and prosthetically driven approach is crucial. Further well sized and designed trials with novel biomaterials need to be undertaken, and the role of artificial intelligence in predicting healing and assisting clinical decision-making could be explored.

CLINICAL SIGNIFICANCE

By advancing our understanding of alveolar socket healing and its management strategies, clinicians can make more informed decisions regarding patient and site level assessment and selection, surgical techniques, and biomaterial choices, ultimately contributing to the enhanced healing process with reduced complications and improved quality of life for patients undergoing tooth extraction and dental implant treatments.

Analysis of risk factors related to early implant failure: A retrospective study

STATEMENT OF PROBLEM

Factors influencing early implant failure (failure during the healing period) in the rehabilitation and restoration of oral function in partially edentulous patients are unclear.

PURPOSE

The purpose of this clinical study was to investigate several factors that may be associated with early implant failure.

MATERIAL AND METHODS

This retrospective study was conducted on 3247 implants in 2061 patients between 2009 and 2022. Patient-related and surgery-related factors, including smoking; sex; diabetes; bone grafting; implant length, diameter, and design; adjacent teeth; and insertion torque, were manually retrieved and analyzed. Using univariate and multivariate analyses, a generalized estimating equation (GEE) model with chi-squared tests was employed to evaluate factors related to early implant failure (the failure before restoration) (α=.05).

RESULTS

The mean ±standard deviation age of the study patients was 49.2 ±15.0 years (range 18 to 91). Ninety-nine implants (3.05%) failed during the healing period. Three factors were statistically significant regarding early implant failure: smoking (odds ratio [OR]=1.92, P=.008), implant design (tapered implants) (OR=1.84, P=.007), and implant length <10 mm (OR=2.98, P=.011). Factors including diabetes, bone grafting, anatomic location, adjacent teeth (endodontic therapy in the adjacent teeth and the distance between implant and adjacent teeth), healing method, and insertion torque did not exhibit a statistically significant higher early implant failure rate. Ninety-three sites with failed implants received new implants, and 6 of these 93 implants failed during the healing period.

CONCLUSIONS

Within the limitation of sample size, smokers, implant length (<10 mm), and implant design (tapered implant) exhibited higher risk of early implant failure in this retrospective study. Implant insertion torque, healing method, adjacent teeth, and diabetes did not significantly influence the risk of early implant failure.

Clinical outcomes of 3-5 years follow-up of immediate implant placement in posterior teeth: a prospective study

BACKGROUND

Immediate implant placement in posterior teeth has become popular in recent years. However, only a few studies focused on evaluating the long-term success of immediate implant placement.

PURPOSE

To analyze the clinical outcomes of immediate implant placement in the posterior region with conventional loading with 3-5 years follow-up following the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference.

METHOD

The study was done in 25 bone-level implants (Straumann® SLActive® bone level tapered implant, Straumann®, Basel, Switzerland) in 19 patients who underwent immediate implant placement in a posterior tooth with conventional loading with 3-5 years follow-up. The overall success and survival of these placements were evaluated following the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference using chart records, clinical examination, radiographic evaluation, and outcomes measurement. Patient satisfaction was evaluated by using a numeric rating scale. The biological and technical status, modified Pink Esthetic Score (mPES), complications, and marginal bone change were also evaluated. The analysis was done using SPSS version 21 (SPSS Inc., Chicago, IL, USA). The data were analyzed using a paired samples t-test.

RESULTS

It was found that 24 out of the 25 (96%) dental implants survived for an average of 57 ± 8.07 months. All of the 24 surviving dental implants were considered an operational success. The average mPES was 9.75 ± 0.44. The major prosthetic complications seen were: (1) proximal contact loss (41.67%), (2) loosening of the screw (8.33%), and (3) cement debonding (4.17%).

CONCLUSIONS

Immediate implant placement in a posterior tooth with conventional loading yields a predictable result with some complications. The most prominent complications were proximal contact loss, followed by loosening of the screw and cement debonding. The implant survival rate was 96% at a mean time follow-up of 4 years and 9 months.

Efficacy of Alveolar Ridge Preservation in Periodontally Compromised Molar Extraction Sites: A Systematic Review and Meta-Analysis

AIM

To investigate the efficacy of alveolar ridge preservation (ARP) in periodontally compromised molar extraction sites.

METHODS

An electronic search was performed on 10th November 2023 across five databases, seeking randomised/non-randomised controlled trials (RCTs/NCTs) that included a minimum follow-up duration of four months. The RoB2 and Robins-I tools assessed the risk of bias for the included studies. Data on alveolar ridge dimensional and volumetric changes, keratinized mucosal width, and need for additional bone augmentation for implant placement were collected. Subsequently, a meta-analysis was carried out to derive the pooled estimates.

RESULTS

Six studies were incorporated in the present review, and a total of 135 molar extraction sockets in 130 subjects were included in the meta-analysis. ARP was undertaken in 68 sites, and 67 sites healed spontaneously. The follow-up time ranged from 4 to 6 months. The meta-analysis of both RCTs and NCTs showed significant differences in mid-buccal ridge width changes at 1 mm level below ridge crest with a mean difference (MD) of 3.80 (95% CI: 1.67-5.94), mid-buccal ridge height changes (MD: 2.18; 95% CI: 1.25-3.12) and volumetric changes (MD: 263.59; 95% CI: 138.44-388.74) in favour of ARP, while the certainty of evidence is graded low to very low. Moreover, ARP appeared to reduce the need for additional sinus and bone augmentation procedures at implant placement with low certainty of evidence.

CONCLUSIONS

Within the limitations of this study, alveolar ridge preservation in periodontally compromised extraction sites may, to some extent, preserve the ridge vertically and horizontally with reference to spontaneous healing. However, it could not eliminate the need for additional augmentation for implant placement. Further, longitudinal studies with large sample sizes and refined protocols are needed.

Five-year outcomes of immediate implant placement for mandibular molars with and without chronic apical periodontitis: A retrospective study

BACKGROUND

Most physicians consider molars with chronic apical periodontitis (CAP) lesions as contraindications for immediate implant placement. At the patient’s request, we perform immediate implant placement of the mandibular molars with CAP in clinical practice.

AIM

To retrospectively analyze and compare the 5-year outcomes of immediate implant placement of the mandibular molars with CAP and those without obvious inflammation.

METHODS

The clinical data of patients with immediate implant placement of the mandibular molars in the Department of Oral and Maxillofacial Surgery, the Affiliated Hospital of Qingdao University, from June 2015 to June 2017 were collected. The patients were divided into CAP (n = 52) and no-CAP (n = 45) groups. Changes in bone mineral density and bone mass around implants were analyzed 5 years after implant restoration.

RESULTS

At 5 years after implantation, the peri-implant bone mineral density was 528.2 ± 78.8 Hounsfield unit (HU) in the CAP group and 562.6 ± 82.9 HU in the no-CAP group (P = 0.126). Marginal bone resorption around implants did not differ significantly between the two groups, including buccal (P = 0.268) or lingual (P = 0.526) resorption in the vertical direction or buccal (P = 0.428) or lingual (P = 0.560) resorption in the horizontal direction. Changes in the peri-implant jump space did not differ significantly between the two groups, including the buccal (P = 0.247) or lingual (P = 0.604) space in the vertical direction or buccal (P = 0.527) or lingual (P = 0.707) space in the horizontal direction. The gray value of cone-beam computed tomography measured using Image J software can reflect the bone mineral density. In the CAP area, the gray values of the bone tissue immediately and 5 years after implant placement differed significantly from those of the surrounding bone tissue (P < 0.01).

CONCLUSION

The results of this study suggest that immediate implant placement of the mandibular molars with CAP can achieve satisfactory 5-year clinical results, without significant differences in the complications, survival rate, or bone tissue condition from the no-CAP mandibular molars.

Five-year outcomes of immediate implant placement for mandibular molars with and without chronic apical periodontitis: A retrospective study

BACKGROUND

Most physicians consider molars with chronic apical periodontitis (CAP) lesions as contraindications for immediate implant placement. At the patient's request, we perform immediate implant placement of the mandibular molars with CAP in clinical practice.

AIM

To retrospectively analyze and compare the 5-year outcomes of immediate implant placement of the mandibular molars with CAP and those without obvious inflammation.

METHODS

The clinical data of patients with immediate implant placement of the mandibular molars in the Department of Oral and Maxillofacial Surgery, the Affiliated Hospital of Qingdao University, from June 2015 to June 2017 were collected. The patients were divided into CAP (n = 52) and no-CAP (n = 45) groups. Changes in bone mineral density and bone mass around implants were analyzed 5 years after implant restoration.

RESULTS

At 5 years after implantation, the peri-implant bone mineral density was 528.2 ± 78.8 Hounsfield unit (HU) in the CAP group and 562.6 ± 82.9 HU in the no-CAP group (P = 0.126). Marginal bone resorption around implants did not differ significantly between the two groups, including buccal (P = 0.268) or lingual (P = 0.526) resorption in the vertical direction or buccal (P = 0.428) or lingual (P = 0.560) resorption in the horizontal direction. Changes in the peri-implant jump space did not differ significantly between the two groups, including the buccal (P = 0.247) or lingual (P = 0.604) space in the vertical direction or buccal (P = 0.527) or lingual (P = 0.707) space in the horizontal direction. The gray value of cone-beam computed tomography measured using Image J software can reflect the bone mineral density. In the CAP area, the gray values of the bone tissue immediately and 5 years after implant placement differed significantly from those of the surrounding bone tissue (P < 0.01).

CONCLUSION

The results of this study suggest that immediate implant placement of the mandibular molars with CAP can achieve satisfactory 5-year clinical results, without significant differences in the complications, survival rate, or bone tissue condition from the no-CAP mandibular molars.

Influence of Smoking on Periodontal and Implant Therapy: A Narrative Review

BACKGROUND

smoking is considered the most modifiable risk factor for periodontal disease.

OBJECTIVE

the aim of this narrative review is to emphasize the effect of smoking on periodontal and implant therapy.

METHODS

The authors reviewed the literature reporting the clinical outcomes of smoking on periodontal surgical and nonsurgical treatment. The impact of smoking on implant therapy and sinus lifting procedures were also reviewed.

RESULTS

Periodontal and implant therapy outcomes are adversely affected by smoking. Smokers respond less favorably to periodontal therapy and periodontal flap procedures as compared to nonsmokers. Clinical outcomes for smokers are 50-75% worse than for nonsmokers. Studies reveal that smokers experience a significantly lower reduction in pocket depth compared to nonsmokers as well as less bone growth after treating infra-bony defects with guided tissue regeneration. The relative risk of implant failure is significantly higher in patients who smoke 20 cigarettes or more per day compared to nonsmokers. Additionally, smoking has also been shown to increase postoperative wound dehiscence and infection rates following sinus floor elevation. Longitudinal studies on smoke cessation have shown a reduction in bone loss and probing depths for periodontitis patients after cessation compared to those who smoke.

CONCLUSION

Smoking cessation can reduce probing depths and improve clinical attachment after nonsurgical periodontal therapy. There is insufficient evidence regarding the effect of smoking on peri-implantitis, as well as the loss of implants in the long-term.

Single-rooted extraction socket classification: A systematic review and proposal of a new classification system based on morphologic and patient-related factors

Taxonomy and classification of a disease contributes to facilitating the diagnosis and treatment planning process and simplifies communication between clinicians. The aim of this study was to provide a critical appraisal based on a systematic review of the single-rooted extraction socket (ES) classifications and subsequently, introduce a new classification system combining the cornerstones of the previously proposed systems and based on the latest consensus in implant dentistry. Following the systematic search process in PubMed, EMBASE, and SCOPUS databases 13 ES classifications were detected. The most repeated hard and soft tissue factors in the previous classifications were buccal bone dehiscence, interproximal bone, gingival recession, and soft tissue phenotype. However, there was minimal attention to patient-related factors such as systemic conditions and smoking. Therefore, a new classification system based on the combination of patient-related factors, clinical and radiographical parameters was proposed. This divides an ES into three types. Class I and II sockets are candidates for receiving immediate implant placement and conversely, a class III socket includes a compromised condition that requires multiple-stage reconstruction mostly suitable for standard delayed implant placement with alveolar ridge preservation. Within the limitations of this study, the new classification system not only provides comprehensive inclusion of various crucial parameters in implant placement (such as prediction of future implant position and osteotomy difficulty, etc.) but also, in contrast to the previously introduced systems, is able to classify the ES prior to extraction and also, takes into the account the patient-related factors as the class modifiers following the extraction.

Effects of Magnetic Stimulation on Dental Implant Osseointegration: A Scoping Review

This PRISMA-ScR driven scoping review aims to evaluate the influence of magnetic field stimulation on dental implant osseointegration. Seven databases were screened adopting ad-hoc strings. All clinical and preclinical studies analyzing the effects of magnetic fields on dental implant osseointegration were included. From 3124 initial items, on the basis of the eligibility criteria, 33 articles, regarding both Pulsed ElectroMagnetic Fields (PEMF) and Static magnetic Fields from permanent Magnets (SFM) were finally included and critically analyzed. In vitro studies showed a positive effect of PEMF, but contrasting effects of SFM on bone cell proliferation, whereas cell adhesion and osteogenic differentiation were induced by both types of stimulation. In vivo studies showed an increased bone-to-implant contact rate in different animal models and clinical studies revealed positive effects on implant stability, under magnetic stimulation. In conclusion, although positive effects of magnetic exposure on osteogenesis activity and osseointegration emerged, this scoping review highlighted the need for further preclinical and clinical studies. More standardized designs, accurate choice of stimulation parameters, adequate methods of evaluation of the outcomes, greater sample size and longer follow-ups are needed to clearly assess the effect of magnetic fields on dental implant osseointegration.

Etiology, occurrence, and consequences of implant loss

Implant therapy aims at providing the patient with a functional and esthetically pleasing rehabilitation in a long‐term perspective. The loss of an implant constitutes a major complication, which may have an impact on the treatment plan and/or jeopardize the longevity of the restoration. Implant loss may occur during the phase of osseointegration (early) or at a later time when the previously achieved osseointegration is lost (late). The present work evaluates the evidence on the occurrence of both events and discusses etiology, risk factors, and consequences.

Lipid Nanocarriers-Loaded Nanocomposite as a Suitable Platform to Release Antibacterial and Antioxidant Agents for Immediate Dental Implant Placement Restorative Treatment

Immediate implant placement is a single-stage restorative approach for missing teeth widely used to overcome the ridge remodeling process occurring after dental extractions. The success of this procedure relies on opportune osseointegration in the surrounding tissues. To support this process, a multifunctional nanocomposite, to be applied in the fresh post-extraction socket, was here designed, prepared, and characterized. This formulation consists of quercetin (QRC)-loaded nanostructured lipid carriers (NLCs) entrapped in a chitosan-based solid matrix containing ciprofloxacin (CPX). QRC-NLCs were prepared by homogenization followed by high-frequency sonication, and thereafter this dispersion was trapped in a chitosan-based CPX-loaded gel, obtaining the nanocomposite powder (BioQ-CPX) by lyophilization. BioQ-CPX displayed desirable properties such as high porosity (94.1 ± 0.5%), drug amounts (2.1% QRC and 3.5% CPX). and low swelling index (100%). Moreover, the mechanism of drug release from BioQ-CPX and their ability to be accumulated in the target tissue were in vitro and ex vivo elucidated, also by applying mathematical models. When trapped into the nanocomposite, QRC stressed under UV light exposure (50 W) was shown to maintain its antioxidant power, and CPX and QRC under natural light were stable over nine months. Finally, both the measured antioxidant power and the antimicrobial and antibiofilm properties on Staphylococcus aureus demonstrated that BioQ-CPX could be a promising platform to support the single-stage dental restorative treatment.

Programmed core-shell electrospun nanofibers to sequentially regulate osteogenesis-osteoclastogenesis balance for promoting immediate implant osseointegration

The biology of immediate post-extraction implant osseointegration is mediated by a coordinated cascade of osteoblast-osteoclast interactions. The aim of this study was to develop a dual-delivery system that allowed sequential release of substance P (SP) to promote bone regeneration and alendronate (ALN) to reduce bone resorption, which will improve the implant osseointegration. We used coaxial electrospinning to fabricate the core-shell poly lactic-co-glycolic acid (PLGA)/gelatin nanofibers, which consists of SP in the shell and ALN in the core. This programmed delivery system was shown to release SP and ALN sequentially to match the spatio-temporal specificity of bone healing. The migration assay demonstrated that the SP-ALN dual-delivery system increased bone marrow mesenchymal stem cells (BMSCs) transmigration. Besides, the expression of osteogenic/osteoclastic markers, Alizarin Red staining, tartrate-resistant acid phosphatase (TRAP) staining, F-actin staining and bone resorption experiment showed that the dual-delivery system can render a microenvironment favorable for osteogenic differentiation and adverse to osteoclastogenesis. Using a rat immediate implant model, we validated the promoted osteogenic property and osseointegration around the implants of SP-ALN dual-delivery system by micro-computed tomography (micro-CT) and histological analysis. These findings suggest that the dual-delivery system with time-controlled release of SP and ALN by core-shell nanofibers provides a promising strategy to facilitate immediate implant osseointegration through favorable osteogenesis. STATEMENT OF SIGNIFICANCE: Immediate implant placement is potentially challenged by the difficulties in achieving primary implant stability and early osteogenesis. Initial period of osteointegration is regulated by osteoblastic/osteoclastic cells resulting in a coordinated healing process. To have an efficient bone regeneration, the coaxial electrospinning was used to fabricate a programmed dual-delivery system. The SP released rapidly and favored for BMSCs migration and osteogenic differentiation, while the sustained release of ALN can reduce the bone resorption. The rat immediate implant model indicated that the SP-ALN dual-delivery system could present the promoted peri‑implant osteogenic property and osseointegration through modulating the osteogenesis-osteoclastogenesis balance. This work highlights the sequential dual delivery of SP and ALN has a promising potential of achieving enhanced osseointegration for immediate implant placement.

Survival rate and potential risk indicators of implant loss in non-smokers and systemically healthy periodontitis patients: An up to 9-year retrospective study

BACKGROUND

An increasing number of patients with chronic periodontitis (CP) have received implant restoration. However, very few studies have evaluated the probable risk indicators of implant loss in patients with CP.

OBJECTIVE

The aim of this study is to evaluate implant long-term survival rates in patients with CP. The results are analyzed to discern potential risk indicators of implant loss.

METHODS

A total of 1549 implants were inserted in 827 non-smokers and systemically healthy CP patients between March 2011 and March 2019. Clinical variables (age; sex; implant location; implant diameter; implant length; implant type; bone quality; bone graft, periodontal disease status, and insertion torque) were recorded. Kaplan-Meier survival curves illustrated the cumulative survival rate. The relationship between variables and implant loss was discerned by univariate analysis. Further multivariate Cox proportional hazard regression analysis was carried out for the variables with P < 0.2.

RESULTS

The cumulative survival rates were 98.8% after 3 months, 97.9% after 6 months, 97.7% after 1 year, and 97.4% after 2 to 9 years. After adjusting possible confounders, the multivariable Cox regression model revealed statistically significant influences of implant location, history of bone graft, and insertion torque on implant loss. Implants with history of bone graft were more likely to loss. Implants inserted in the anterior area had a higher implant loss risk; insertion torque of <15 Newton-centimeter (Ncm) showed a relatively high risk of being lost.

CONCLUSIONS

The study represented public hospital insight into long-term implant results of patients with CP. Under the premise of strict periodontal control, patients with the history of CP exhibited relatively high implant survival rate. Anterior implant location, history of bone graft, and insertion torque <15 Ncm are associated with a lower implant survival rate and could be considered at a higher risk of implant failure in patients with CP.

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.

Survival of dental implants at sites after implant failure: A systematic review

STATEMENT OF PROBLEM

Despite an overall high survival rate for dental implants, the effectiveness of implant retreatment remains unclear.

PURPOSE

The purpose of this systematic review was to examine the survival rate of implants placed at sites which had an implant failure and to investigate factors that might affect outcomes after retreatment.

MATERIAL AND METHODS

A search of electronic databases limited to English language articles was conducted using the following MeSH terms: "dental implants," "dental implantation," or "dental restoration failure," combined with "retreatment," "replacement," or "reoperation." A hand search of selected journals was also performed. Of the retrieved 668 publications, 8 retrospective clinical studies met the inclusion criteria, providing the survival outcome for 673 implants in 557 patients after retreatment. Implant- and patient-related characteristics related to implant failures were assessed.

RESULTS

The weighted mean survival rate for implants after retreatment was 86.3%, with follow-up ranging from less than 1 year to over 5 years. The survival rates of smooth-surfaced and rough-surfaced implants were compared in 217 retreated implants, revealing a significantly higher survival rate for rough-surfaced implants than for smooth-surfaced implants (90% versus 68.7%). Insufficient data were available to evaluate the effect of patient- or treatment-related characteristics on the survival of implants after retreatment.

CONCLUSIONS

The survival rate of retreated implants is lower than that generally reported after initial implant placement. Higher survival rates were reported with rough-surfaced implants than with smooth-surfaced implants in retreatment. An overall implant survival rate of 86.3% after retreatment suggests that most initial implant failures are likely attributable to modifiable risk factors, such as implant architecture, anatomic site, infection, and occlusal overload.

Novel Use of Silicone Sheets for Immediate Implant Placement in Fresh Molar Extraction Sockets

In the recent years, the immediate placement of dental implants into fresh extraction sites has become an acceptable treatment approach. However, immediate molar implant placement presents specific challenges because of the anatomical and physiologic limitations. Such implant surgeries commonly require procedures that use a barrier membrane to generate bone and soft tissue or one that seals the molar extraction socket through a coronally advanced flap. Here, as an alternative, we report a method for treating molar extraction socket wounds in the hard and soft tissues after immediate placement of an implant using a silicone sheet.

Monte Carlo simulation of reasons for early failure of implants: effects of two risk factors

We have estimated the joint effects of two important risk factors on early failure of implants and then ranked all quoted risks by importance. We made a systematic search of published papers listed in PubMed, Web of Knowledge, Scopus, and Cochrane Central up to March 2018, and identified a total of 437 records. Eight studies met the inclusion criteria, in which seven significant risk factors for early failure were selected and used to build a conceptual simulation model. Selected risk factors were: "male sex", "smoking", "quality of bone", "short implants", "wide implants", "adjacent teeth", and "periodontitis". Based on these risk factors, all two-factor combinations that accounted for a total of 21 areas of greatest risk were created. We made a Monte Carlo simulation with 10 000 iterations and a sensitivity analysis to evaluate the estimates of these risks and to identify those that had the most influence on the model of early failure. The outcomes of the Monte Carlo simulation model showed that the SRS values of the combinations of these risks had different ranges of effects and probabilities of the early risk of failure. As a result, the most sensitive areas of greatest risk were "smoking and periodontitis", the second "short implants and periodontitis", and the third "smoking and short implants". The least sensitive combination of risks for early failure was "wide implants and male sex". This is to our knowledge the first study that has illustrated the contributions of various combinations of risk factors to early failure of implants. "Smoking and periodontitis" was thought to be associated with the greatest risk of early failure.

Augmentation versus No Augmentation for Immediate Postextraction Implants

Purpose

To assess the effects of augmentation versus no augmentation in patients restored with immediate postextraction single-tooth implants on implant failure and patient satisfaction.

Materials and methods

We searched the Cochrane Oral Health Group Trial Register, Cochrane Central Register of Controlled Trials, MEDLINE, and the WHO International Clinical Trial Registry Platform (22 March 2017). Two reviewers independently assessed trials for inclusion and risk of bias, extracted data, and checked for accuracy. We have expressed results as risk ratio or mean differences, together with their 95% confidence intervals.

Results

We included six studies (287 participants). Two trials compared no augmentation versus bone graft augmentation and reported no implant failures in both groups after a follow-up period of 6 months (20 implants) and 1 year (34 implants). One trial compared bone graft augmentation versus membrane augmentation and reported no difference in implant failure between both groups after 6 months (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.06 to 15.31) or 1 year of follow-up (RR 0.33, 95% CI 0.01 to 7.86), and no implants were lost after 3 years. Three trials compared membrane augmentation versus combined bone graft and membrane augmentation, and there was no difference between the groups after six months of follow-up in implant failure (RR 5.13, 95% CI 0.63 to 41.93) or after 1 year (RR 0.38, 95% CI 0.02 to 9.05). There was insufficient evidence regarding patient satisfaction in all the included trials.

Conclusions

In patients restored with immediate postextraction single-tooth implants, there is insufficient evidence to recommend simultaneous augmentation or a certain augmentation protocol to enhance implant survival and patient satisfaction. This trial is registered with PROSPERO (CRD42017054439).

Contribution of the PDL to Osteotomy Repair and Implant Osseointegration

Our objective was to clarify the fate of the periodontal ligament (PDL) retained in the socket after tooth extraction, then determine if this tissue contributed to the osseointegration of "immediate" implants placed in these fresh extraction sockets. Mice underwent maxillary first molar extraction, the residual PDL was removed by an osteotomy, and titanium implants were placed. The osteotomy was created in such a way that the palatal surface was devoid of PDL remnants while the buccal, mesial, and distal surfaces retained PDL fibers. At multiple time points after surgery, tissues were analyzed using a battery of molecular, cellular, and histomorphometrical assays. We found that PDL remnants mineralized and directly contributed to new bone formation in the extraction site. Compared with regions of an extraction site where the PDL was removed by osteotomy, regions that retained PDL fibers had produced significantly more new bone. Around immediate implants, the retained PDL remnants directly contributed to new bone formation and osseointegration. Thus, we conclude that PDL remnants are inherently osteogenic, and if the tissue is healthy, it is reasonable to conclude that curetting out an extraction socket prior to immediate implant placement should be avoided. This recommendation aligns with contemporary trends toward minimally invasive surgical manipulations of the extraction socket prior to immediate implant placement.

Risk Factors in Early Implant Failure: A Meta-Analysis

BACKGROUND

Clinicians should be able to weigh the role of the main risk factors associated with early implant failure.

PURPOSE

The aim of this meta-analysis was to assess the influence of different patient-related and implant-related risk factors on the occurrence of early implant failure.

MATERIALS AND METHODS

In July, 2014 the main electronic databases were searched for studies reporting on early failures. Relevant papers were selected by 2 independent authors using predefined selection criteria. Three authors independently scored the included studies for quality assessment. The estimated odds ratios of the main risk factors from the selected papers were subjected to meta-analysis.

RESULTS

Nine studies were included. A total of 18,171 implants were meta-analyzed, of which 10,921 were analyzed for smoking, 15,260 for implant diameter, 16,075 for implant length, and 16,711 for implant location (maxilla vs mandible). The main significant risk factors for early implant failures were the smoking habit (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.3, 2.3), implants shorter than 10 mm (OR, 1.6; 95% CI, 1.2, 2.2) and implants placed in the maxilla (OR, 1.3; 95% CI, 1.0, 1.6).

CONCLUSIONS

Clinicians should be aware of the increased risk of early failure in the presence of smokers, implants with reduced length, and implant-supported maxillary rehabilitation.

The efficacy of 0.12% chlorhexidine versus 0.12% chlorhexidine plus hyaluronic acid mouthwash on healing of submerged single implant insertion areas: a short-term randomized controlled clinical trial

OBJECTIVES

The study was performed to evaluate the incidence of post-surgical adverse events at submerged implant sites as well as the antiplaque, antigingivitis and antistaining effects in the entire dentition of patients treated with two mouthwashes.

METHODS

The present randomized controlled clinical study considered 40 patients subjected to dental implant treatment. Two 0.12% chlorhexidine mouthwashes were compared for 15 days: one with 0.1% hyaluronic acid (CHX⊗HYL group) and one without it (CHX group). Surgical outcome variables, and plaque, gingival, and staining indexes were recorded.

RESULTS

Significant differences were found between the two rinses regarding the presence of oedema within 2 days after surgery (20% for the CHX⊗HYL group and 78% for the CHX group). No other significant differences were recorded between the two mouthwashes. No intergroup differences in plaque, staining and gingivitis indexes were registered. The intragroup analysis revealed that for the plaque and gingival indexes, the differences between the baseline values (before surgery) and those at 15 days were all found to be significant just for CHX⊗HYL rinse, with final values ranging from 0.18 to 0.23 for the plaque index and from 0.06 to 0.07 for the gingival index. The staining index increased for both mouthwash types with significant results (with final value of 0.19 and 0.31 for CHX⊗HYL and CHX groups, respectively).

CONCLUSIONS

In the sites of patients subjected to dental implant placement, an additional anti-oedematigenous effect in early healing seemed to be disclosed for 0.12% CHX⊗HYL mouthwash. Regarding antiplaque and antigingivitis activities, HYL seemed to be ineffective.

Survival and success rate of one-piece implant inserted in molar sites

Background:

Recently, the use of one-piece implants (OPI) has become more popular. Since no reports specifically focus on OPIs inserted in molar areas, a retrospective study has been performed.

Materials and Methods:

A series of 36 OPIs (Diamond; BIOIMPLANT, Milan, Italy) were inserted into the molar area of patients admitted at the Dental Clinic, University of Chieti, Italy, for oral rehabilitation between January and December 2010.

Results:

In our series survival rate (SVR) and success rate (SCR) were 91.7% and 97%, respectively. Statistical analysis demonstrated that no studied variable has an impact on survival (i.e., lost implants) as well as on clinical success (i.e., crestal bone resorption).

Conclusion:

OPIs are reliable devices for oral rehabilitation in the molar areas.