Occurrence Of Peri-implantitis Research Articles

Stabilized oral lichen planus does not compromise dental implants survival: A systematic review and meta-analysis.

This study aimed to evaluate the incidence of implant failure in patients with oral lichen planus (OLP) and investigate the potential association between OLP and peri-implant diseases. Embase, Web of Science, PubMed, and Scopus databases were searched for studies with no time restrictions. Meta-analysis was performed calculating pooled proportion of peri-implantitis (PI), peri-implant mucositis (PIM), and bleeding on probing (BOP) prevalence using fixed-effects model. Odds ratio and corresponding 95% CI were calculated to assess the potential risk of PI, PIM, and BOP in dental implant patients with OLP compared to healthy controls. Implant failure rate was 4.38% at the patient level and 4.37% at the implant level. Six patients (3.92%) from five studies were diagnosed with oral cancer after receiving implant. The prevalence of PI, PIM, and BOP at the implant level were 14.00%, 20.00%, and 40.00%, respectively. There was no significant difference in the occurrence of PI and PIM between OLP patients and healthy controls. Stabilized OLP is not considered a significant risk factor for peri-implant diseases. It is advised against placing implants or prostheses during the acute phase of the disease. Histopathological investigation to differentiate OLP from oral lichenoid dysplasia is crucial.

Analysis of the Association of IL-1A, IL-1B and IL-1RN Polymorphisms with Peri-implantitis in a Portuguese Population.

The aim of this study was to investigate whether genetic variations in cytokine genes involved in the pathogenesis of peri-implantitis, could be associated with its occurrence, an issue that remains controversial and may vary according to the population evaluated. A cross-sectional analytical study was carried out on 102 Portuguese Caucasian individuals divided into two groups: 43 individuals with peri-implantitis and 59 individuals with peri-implant health. Samples from the buccal mucosa were obtained and genetic analysis was performed using the real-time polymerase chain reaction (PCR) technique for IL-1A and IL-1B and using PCR and restriction fragment length polymorphism analysis for IL-1RN. The IL-1A -889 C/T polymorphism showed a higher prevalence of the less common allele (T allele) in cases of peri-implantitis than in healthy cases (27.9% vs 16.9%, respectively), but without statistical significance (p = 0.060). For the IL-1B +3954 C/T and IL-1RN (variable number of tandem repeats) polymorphisms, the analysis revealed that the allele and genotype frequencies did not differ significantly between groups. There was a significant association between a history of periodontitis and peri-implantitis (p = 0.020). The genetic polymorphisms evaluated had no influence on the occurrence of periimplantitis in the population studied. Further research into genetic variations in different populations is needed to elucidate the role of genetic factors in the onset and progression of periimplant disease.

The Influence of Genetic Polymorphisms on the Expression of Interleukin-1beta, Prostaglandin E2 and Tumor Necrosis Factor Alpha in Peri-Implant Crevicular Fluid: A Cross-Sectional Study.

The aim of this study was to evaluate the possible relationships between polymorphisms in the interleukin-1 (IL-1) A, IL-1B, and IL-1RN genes and concentrations of the inflammatory mediators IL-1β, tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2) in peri-implant crevicular fluid (PICF). A cross-sectional analytical study was conducted on 51 patients with dental implants. Samples from the buccal mucosa were obtained, and genetic analysis was performed using the real-time polymerase chain reaction (PCR) technique for IL-1A and IL-1B and PCR and restriction fragment length polymorphism analysis for IL-1RN. For the biochemical analysis, the concentrations of IL-1β and TNF-α were analyzed using multiplexed fluorescent sphere immunoassays, and PGE2 by enzyme-linked immunosorbent assay. In patients with detected IL-1RN polymorphism, there was an increase in the concentration of the three mediators with statistically significant differences in the mean values of TNF-α and PGE2, regardless of peri-implant health status (p = 0.002 and p = 0.049, respectively). The concentrations of all three mediators were positively and significantly correlated (IL-1β vs. TNF-α Rho = 0.480, p < 0.001; IL-1β vs. PGE2 Rho = 0.382, p = 0.006; and TNF-α vs. PGE2 Rho = 0.528, p < 0.001). We can conclude that the IL-1RN polymorphism exerts an influence on the PICF immune response, which may explain the influence of this genetic polymorphism on the occurrence of peri-implantitis.

Influence of factors of systemic inflammation and endothelial dysfunction in somatic pathologies on the success of dental implantation (literature review)

In the presented literature review, the issue of the influence of general somatic factors associated with diseases of the cardiovascular and endocrine systems on the success of dental implantation was studied. The issues of the relationship of systemic inflammatory processes and periodontal status with the dental health of patients with background pathologies associated with an imbalance of pro- and anti-inflammatory cytokines, insulin and glucose in the blood in diabetes mellitus and obesity, factors of endothelial dysfunction in atherosclerosis, hypertension and coronary heart disease are highlighted. Based on the analyzed information, it was confirmed that poor-quality history taking, the lack of a thorough diagnostic examination (biochemical blood test, coagulogram, reaction to the presence of specific infections and viral diseases), ignoring the need to correct existing local and systemic inflammatory phenomena before dental implantation can lead to a violation the process of osseointegration, the occurrence of peri-implantitis, implant rejection reactions. In this regard, it can be concluded that when planning complex dental treatment, attention should be paid not only to local dental symptoms, but also to the general history and laboratory data, which will improve the quality of dental implantation.

Rough Implants in Vertically Augmented Bone: A Retrospective Study with 4 to 15 Years of Follow-up

Although vertical guided bone regeneration (v-GBR) is a popular technique for treating alveolar bone deficiency, there are no long-term studies analyzing the longevity and success of the results. This retrospective study analyzes the clinical and radiographic outcomes of oxidized implants placed after v-GBR, with a follow-up period of 4 to 15 years. The study considers 41 v-GBR patients receiving one or more dental implants between 2001 and 2013 (115 implants total). Clinical and radiographic outcomes were recorded during follow-up visits. A multiple logistic regression model was used to analyze the correlation between peri-implantitis and demographic, surgical, and clinical variables, as well as the length of the follow-up period. The cumulative survival rate of the implants over the mean follow-up period of 9.6 ± 3.4 years was 95.7%, with peri-implantitis observed in 26.1% of the implants. The variables that correlated with the occurrence of peri-implantitis were smoking (OR = 8.5, 95% CI = 1.6 to 44.5, P < .01), posterior mandible implant position (OR = 2.1, 95% CI = 1.2 to 3.9, P < .01), and the length of the follow-up period (OR = 1.5, 95% CI = 1.1 to 2.2, P < .01). In this study, smoking, time since the surgery, and the implant position were associated with peri-implantitis developing on rough surface implants. Along with with previous long-term follow-up studies, this suggests that oxidized surface implants have a higher risk of peri-implantitis than machined ones.

Is one-stage lateral sinus lift and implantation safe in severely atrophic maxillae? Results of a comparative pilot study

PurposeThe aim of this retrospective comparative study was to evaluate the survival of dental implants placed in the posterior maxilla with a residual bone height less than 3 mm using a one-stage lateral sinus lifting approach. The research question was whether in very severely atrophied maxillary bones (residual height < 3 mm), a sinus lift with simultaneous implant placement would be associated with a higher complication rate compared to single-stage sinus lifts at average residual alveolar process heights.MethodsComplications of 63 implants, where the residual bone height was below 3 mm, were compared to a reference group of 40 implants, which were inserted using a one-stage lateral sinus lift in maxillae with at least 3 mm residual bone height. Implant survival, bleeding-on-probing, the presence of peri-implant mucositis and the occurrence of peri-implantitis were documented.ResultsThe mean follow-up time for implant survival was 80.3 ± 25.9 months. One implant out of 63 was lost in the severely atrophic maxilla group and two implants out of 40 were lost in the reference group. There were no differences in the occurrence of implant loss (p = 0.558), bleeding-on-probing (p = 0.087), peri-implantitis (p = 0.999) and peri-implant mucositis (p = 0.797) between the severely atrophic alveolar ridge group and the reference group.ConclusionsEven in severely atrophic maxillae with < 3 mm residual bone height, a one-stage maxillary sinus lift and immediate implant placement can be carried out safely.Graphical

Association between implant surface roughness, smoking habits and implant site location on the occurrence of peri-implantitis: a pooled retrospective cohort study

Background: Peri-implantitis is a multi-factorial disease that affects dental implants surrounding tissues. The identification of risk factors and risk indicators could contribute to explain the heterogeneity of the disease onset and progression. The aim of the present study is to investigate the influence of implant surface roughness and other initial conditions on the future development of peri-implantitis disease by means of a pooled individual data.

Ageing-Associated Transcriptomic Alterations in Peri-Implantitis Pathology: A Bioinformatic Study.

Background Ageing is associated with increased incidence of peri-implantitis but the roles of ageing-associated biological mechanisms in the occurrence of peri-implantitis are not known. This study is aimed at performing integrative bioinformatic analysis of publically available datasets to uncover molecular mechanisms related to ageing and peri-implantitis. Methods Gene expression datasets related to ageing and peri-implantitis (PI) were sought, and differentially expressed genes (DEGs) were analysed. Ageing-related genes were also identified from the “Aging Atlas” database. Using intersection analysis, an age-related-PI gene set was identified. Functional enrichment analysis for enriched GO biological process and KEGG pathways, protein-protein interaction (PPI) network analysis, correlation analysis, and immune cell infiltration analysis to determine high-abundance immune cells were performed. Least absolute shrinkage and selection operator (LASSO) logistic regression identified key age-related-PI genes. Transcription factor-gene and drug-gene interactions and enriched KEGG pathways for the key age-related-PI genes were determined. Results A total of 52 genes were identified as age-related-PI genes and found enriched in several inflammation-associated processes including myeloid leukocyte activation, acute inflammatory response, mononuclear cell differentiation, B cell activation, NF-kappa B signalling, IL-17 signalling, and TNF signalling. LYN, CDKN2A, MAPT, BTK, and PRKCB were hub genes in the PPI network. Immune cell infiltration analysis showed activated dendritic cells, central memory CD4 T cells, immature dendritic cells, and plasmacytoid dendritic cells were highly abundant in PI and ageing. 7 key age-related PI genes including ALOX5AP, EAF2, FAM46C, GZMK, MAPT, RGS1, and SOSTDC1 were identified using LASSO with high predictive values and found to be enriched in multiple neurodegeneration-associated pathways, MAPK signalling, and Fc epsilon RI signalling. MAPT and ALOX5AP were associated with multiple drugs and transcription factors and interacted with other age-related genes to regulate multiple biological pathways. Conclusion A suite of bioinformatics analysis identified a 7-signature gene set highly relevant to cooccurrence of ageing and peri-implantitis and highlighted the role of neurodegeneration, autoimmune, and inflammation related pathways. MAPT and ALOX5AP were identified as key candidate target genes for clinical translation.

Does implant location influence the risk of peri-implantitis?

Peri-implantitis is characterized by nonreversible and progressive loss of supporting bone and is associated with bleeding and/or suppuration on probing. Peri-implant disease is considered as the main etiologic factor related to implant failure. Peri-implant disease has a pathogenesis similar to that of periodontal disease, both being triggered by an inflammatory response to the biofilm accumulation. Although the prevalence of peri-implantitis has been evaluated by several clinical studies with different follow-ups, there are currently little data on the impact of implant location and the prevalence of peri-implantitis. The aim of this review, therefore, was to summarize the evidence concerning the prevalence of peri-implantitis in relation to implant location and associated risk predictors. Even though most studies evaluating the prevalence of peri-implantitis in relation to implant location are cross-sectional or retrospective, they suggest that the occurrence of peri-implantitis is most prevalent in the anterior regions of the maxilla and mandible. Moreover, it seems that there is a higher prevalence of peri-implantitis in the maxilla than in the mandible.

The effect of the use of proton pump inhibitors, serotonin uptake inhibitors, antihypertensive, and anti-inflammatory drugs on clinical outcomes of functional dental implants: Aretrospective study.

ObjectiveThe present retrospective study investigated the effect of chronic intake of proton pump inhibitors, selective serotonin uptake inhibitors, anti‐inflammatory, and antihypertensive drugs on the survival of dental implants and on the occurrence of peri‐implantitis.Materials and methodsSurvival analyses for implant failure and peri‐implantitis were performed patient level for each drug subcategory and for risk factors. The HR for each drug was calculated with adjusted models as compared with a control group made of subjects not assuming the specific drug. Multilevel logistic regression was used to explore the influence of implant‐level and patient‐level variables on the outcomes.ResultsA total of 270 subjects receiving 1118 dental implants were included, with a mean follow‐up time of 5.19 ± 4.22 years. After 10 years, the survival rate was 86.9% (patient level), and according to survival analysis, 61.3% of subjects were free from peri‐implantitis. The use of anti‐inflammatory medicines produced a significant effect (p = .04) on peri‐implantitis as compared to subjects not using the drug, with a 2.7‐year drop in the mean survival time. The HR was slightly above the level of significance in a semiadjusted model (p = .058). The multilevel analysis found a significant effect on the entire sample and not when considering only subjects with implants with more than 1‐year follow‐up.ConclusionsWe found a possible relationship between anti‐inflammatory drug use and the occurrence of peri‐implantitis in the examined cohort of patients, and no correlation for the other drugs.

The long-term impact of alveolar ridge preservation with xenograft bone mineral on peri-implant health after 5 years in function: A retrospective cohort study of 108 patients assessed clinically and radiologically.

ObjectivesWhen teeth are lost, dental implants contribute to improved oral function and quality of life. Limitations in dental implant placement arising from poor bone anatomy may be circumvented via alveolar ridge preservation (ARP). The aim is to evaluate the long‐term impact of ARP on peri‐implant health and the relationship with common risk indicators such as smoking and history of periodontitis.Materials and MethodsOne hundred and eight patients were enrolled in this retrospective cohort study with 308 implants. Of these, ∼41% were placed in bone sites that had previously received ARP with deproteinized bovine bone mineral xenograft. Association between baseline variables: ARP, age, gender, number of implants per patient, anatomical site, smoking, and previous history of grade III/IV periodontitis, and outcome variables: mucositis, peri‐implantitis, implant loss, full‐mouth plaque score (FMPS), full‐mouth bleeding score, and marginal bone loss (MBL) was evaluated using both univariate and multivariate models.ResultsAfter 5 years, the overall survival rate was 93.7%. The occurrence of peri‐implantitis was 21.3% and the extent of MBL was ~2.2 mm. Both peri‐implantitis occurrence and MBL were comparable between ARP+ and ARP−. Smoking is associated with higher FMPS and MBL.ConclusionsThe findings indicate that peri‐implant health can be maintained around dental implants for up to 5 years in ARP+ sites using Bio‐Oss®. Smoking is a major risk indicator for peri‐implantitis, whereas the association between history of periodontitis and the risk of peri‐implantitis, based on this specific, well‐maintained cohort and the specific implants used, remains inconclusive.

Peri-Implantitis: A New Definition Proposal Based on Unnatural Spatial Arrangement and Late Mechanical Coupling between Two Cortical Bone Layers during Osseointegration Phase: Part I

Scientists have been speculating for three decades about the reasons for the occurrence of peri-implantitis around dental implants. Many theories have been proposed since the beginning of 1990. Since then, the dental profession has been exposed to a vast number of peri-implantitis cases, whereas the “disease” had been unknown before this time. However, the situation has not improved because we focus more on how to treat the problem instead of trying to understand it completely. The aim of this paper is to present a purely bone-based explanation for the beginning of the “bone loss” process around already “osseointegrated” implants. Conclusion: There are a number of possible chain reactions of physiological bone response to dental implants which may explain the occurrence of peri-implantitis. Bacteria and “immunological reactions” may not be the main causes of this disease. In the first part, the authors present the principles of bone biology and physiology based on the theories of Donath, Jansen and Frost and transfer them to the field of implantology. They describe the stages of “osseointegration”, explaining the subsequent changes in the bone at the implant–bone interface.

Association between cumulative smoking exposure, span since smoking cessation, and peri-implantitis: a cross-sectional study.

To investigate the association of cumulative smoking exposure and span since smoking cessation with the occurrence of peri-implantitis. A sample of 350 individuals aged ≥ 35years, with the presence of at least one osseointegrated implant functioning for > 5years, were enrolled in the study. According to smoking habits, participants were categorized into 3 groups: non-smokers (NS; n = 212), former smokers (FC; n = 66), and current smokers (CS; n = 72). Complete peri-implant and periodontal examinations were evaluated. Associations between the occurrence of peri-implantitis and smoking habits, as well as potential confounders, were evaluated through univariate and multivariate analyses. The occurrence of peri-implantitis in the NS, FS, and CS groups was 18.2%, 19.7%, and 30.5%, respectively. A high prevalence of the overall number of cases with periodontitis (54.2%) was observed in the CS group when compared to the FS and NS groups. After adjusting for confounders, the odds ratio (OR) for the occurrence of peri-implantitis was 2.63 (1.39-6.77; p < 0.001) for CS compared to NS. There was a significant dose-response relationship between pack/year of smoking and the occurrence of peri-implantitis, as well as a significant decrease in the risk as the years of smoking cessation increased. The occurrence of peri-implantitis among CS was high. The cumulative smoking exposure in an incremental manner and the shorter smoking cessation span was directly associated with a higher risk for peri-implantitis. Educational and preventive strategies in general health services must attempt to reduce the adverse effects of cumulative smoking exposure and to explore the beneficial effects of smoking cessation on peri-implant status.

Association between liver cirrhosis and peri-implant diseases: a case-control study on implant- and patient-related risk factors.

The objective of this study was to evaluate the potential association between liver cirrhosis and peri-implant diseases, as well as the influence of different risk indicators on this association. This case-control study included 64 cases with liver cirrhosis and 128 controls without liver diseases that presented the same socio-demographic and economic profile. The specific inclusion criteria were the following: aged group of 35-55 years and presenting at least one osseointegrated implant functioning for >5 years. A full-mouth peri-implant and periodontal examination was performed and risk variables were recorded. The association between risk variables and the occurrence of peri-implant diseases was tested through univariate analysis and multivariate logistic regression, stratified by alcohol status. Additionally, a mediation analysis was performed to examine the mediating effect of age with peri-implantitis. A high prevalence of peri-implantitis (29.7%) was observed among cases when compared to controls (18.0%). Individuals with cirrhosis presented ~2.5 higher chance of having peri-implantitis than controls (p<0.001). Significant variables associated with the occurrence of peri-implantitis in the final logistic model were the following: cirrhosis, alcohol use, age (>55 years), male sex, smoking, periodontitis, and number of ≤14. An important risk association between liver cirrhosis and peri-implantitis was reported. Future studies with a larger sample size controlling for the patient- and implant-related confounders are needed to better understand the link between peri-implantitis and liver cirrhosis. Cirrhosis individuals, age, and periodontitis, as well as alcohol use and smoking interaction, should be considered as potential risk indicators for peri-implantitis.

Medium- and Long-Term Survival Rates of Implant-Supported Single and Partial Restorations at a Maximum Follow-up of 12 Years: A Retrospective Study.

To present medium- and long-term biologic outcomes of implant-supported single-tooth restorations and fixed partial dentures and to analyze their correlations with prosthesis and patient characteristics. The records of patients treated with implant-supported fixed restorations between 2004 and 2019 reporting the presence or absence of peri-implantitis and/or implant failure were analyzed. The cumulative survival rate (%) over time was calculated, as well as the cumulative prevalence of units free of peri-implantitis. A total of 344 implants in 112 patients were included, with a mean follow-up period of 5.3 ± 4.0 years after loading. The cumulative survival rates for implants supporting single crowns and fixed partial dentures were 98.11% and 100% after 5 years, respectively, and 97.43% and 98.96% after 10 years, with an overall survival rate of 91.69% after 12 years. At the patient level, the implant survival rates were 95.42%, 92.73%, and 85.31% at 5, 10, and 12 years, respectively. The cumulative rate of implants free from peri-implantitis was 87.46% at the implant level and 72.39% at the patient level. Implant and prosthesis characteristics did not affect the long-term occurrence of implant failure or peri-implantitis. The development of peri-implantitis was statistically correlated with patient smoking habits, but not with history of periodontitis or with diabetes mellitus. Implants supporting single crowns and fixed partial dentures showed relatively high medium- and long-term survival rates that were not influenced by the implant or prosthesis characteristics, including the retention method. As for patient characteristics, only smoking was correlated with the occurrence of peri-implantitis.

Factors influencing the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses: A multicenter cross-sectional study.

Peri-implantitis is widely recognized as a major cause of late implant failure, both in pristine and regenerated bone. The present study aims to evaluate the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses and to analyze possible risk factors. A cross-sectional study was conducted in four centers including patients who underwent lateral or transcrestal sinus augmentation and received dental implants. Clinical and anamnestic data were collected using a standardized form. Univariate and multivariate logistic regression analyses have been performed for both implant-level and patient-level variables. Subsequently, a multilevel logistic mixed-effect model was built to analyze variables correlated with the occurrence of peri-implantitis. A total of 156 patients (61 males and 95 females; mean age: 60.9 ± 11.6 years) with 315 implants inserted into augmented maxillary sinuses with a follow-up ranging from 1 to 18 years were evaluated. Seven implants in seven patients were previously lost for peri-implantitis (2.2% and 4.5% at implant- and patient-level, respectively); 250 implants showed no signs of peri-implant diseases (79.4%), 34 implants presented mucositis (10.8%), and 24 implants exhibited peri-implantitis (7.6%). Corresponding data evaluated at patient-level were 125 (80.1%), 17 (10.9%), and 14 (9.0%), respectively. At the multilevel analysis, history of periodontitis, sinus elevation with lateral approach, and one-stage sinus floor elevation significantly correlated with the occurrence of peri-implantitis (P<0.001). History of periodontitis confirmed its well-known role as a risk factor for peri-implant pathologies. In addition, both lateral window technique and one-stage sinus floor elevation seemed to represent significant risk factors for peri-implantitis.

Soft Tissue Management: A Critical Part of Implant Rehabilitation After Vascularized Free-Flap Reconstruction

Implant rehabilitation after jaw reconstruction is challenging, and postoperative peri-implantitis is common. Our aim was to present our management protocol for implant rehabilitation after vascularized free-flap reconstruction and report the outcomes of soft tissue management. This retrospective cohort study included patients who received vascularized free-flap reconstruction, implant rehabilitation, apical reposition flaps (ARFs), and free gingival grafts (FGGs) at Peking University School and Hospital of Stomatology from January 1, 2009 to January 1, 2020. We assessed the association of age, gender, primary disease, flap choice, number and position of implants, timing of ARFs and FGGs, fixation stent use, and restoration type with the occurrence of peri-implantitis. Probing pocket depth, bleeding on probing, and marginal bone loss of the implants were measured as well. The data were analyzed by descriptive statistics, Kaplan-Meier statistics, and Cox regression analysis. In total, 19 patients with 65 implants were included. The implants were placed immediately or 7 to 44months after reconstruction of the jaw with fibular (n=17) or iliac flaps (n=2). ARFs and FGGs were performed 0 to 11months later. No implants were lost. The mean probing pocket depth, bleeding on probing, and marginal bone loss at 26.6±16.8months were 3.5±0.9 mm, 70.4±35.1%, and 0.6±0.4 mm, respectively. The incidence of peri-implantitis was 32.3%, showing no significant associations with the gender, age, primary disease, flap choice, number and position of implants, timing of ARFs and FGGs, use of a fixation stent, and type of restoration based on the adjusted multivariate model (P>.05). Soft tissue management helps generate firmly attached keratinized mucosa around the implants, leads to a more precise impression, and reduces peri-implant bone loss. It should be considered as a critical part of implant rehabilitation after vascularized free-flap reconstruction.

Influence of vertical soft tissue thickness on occurrence of peri-implantitis in patients with periodontitis: a prospective cohort study.

The influence of vertical soft tissue thickness on health of peri-implant tissue has been addressed in few studies; thus, further research is needed. To evaluate the influence of vertical soft tissue thickness on the risk of peri-implantitis and peri-implant condition in patients with a history of periodontitis. A total of 92 patients with a history of periodontitis were included in this study. During the implant placement, the distance from palatal soft tissue edge to the alveolar crest, which was defined as vertical soft tissue thickness, was measured. The characteristics of patients and implants were recorded at baseline (T1). After more than 2 years follow-up period, 65 patients with 159 implants finally came back for T2 evaluation, and parameters of peri-implant tissue were recorded. The associations of vertical soft tissue thickness with peri-implant parameter and occurrence of peri-implantitis were analyzed using the generalized estimating equation accompanying linear regression and logistic regression. In addition to conventional multivariate analysis, a propensity score for adjustment was used to reduce confounding bias. At follow-up examination (T2), survival rate at implant-level was 98.8%. The peri-implant parameters, including peri-implant probing depth and marginal bone loss, increased significantly with the increasing of soft tissue thickness (P < 0.05) after adjusting for a propensity score. In multivariate analysis adjusted for different confounding factors and propensity score, the odd ratios were all approximately 2.5, which meant that the risk of peri-implantitis increased 1.5 times for 1 mm increase of soft tissue thickness. The excessive vertical soft tissue thickness around implants in patients with history of periodontitis has an adverse influence on health of the peri-implant tissue. This observation raises an important question on the association between vertical soft tissue thickness during implant surgery and history of periodontitis. Effective approaches to prevent the adverse effect of excessive soft tissue thickness on peri-implant tissue are necessary to be further investigated.

WITHDRAWN: Interventions for replacing missing teeth: different types of dental implants.

Dental implants are available in different materials, shapes and with different surface characteristics. In particular, numerous implant designs and surface modifications have been developed for improving clinical outcome. This is an update of a Cochrane review first published in 2002, and previously updated in 2003, 2005 and 2007. Primary: to compare the clinical effects of different root-formed osseointegrated dental implant types for replacing missing teeth for the following specific comparisons: implants with different surface preparations, but having similar shape and material; implants with different shapes, but having similar surface preparation and material; implants made of different materials, but having similar surface preparation and shape; different implant types differing in surface preparation, shape, material or a combination of these.Secondary: to compare turned and roughened dental implants for occurrence of early implant failure (before prosthetic loading) and occurrence of peri-implantitis. We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 17 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 12), MEDLINE via OVID (1946 to 17 January 2014) and EMBASE via OVID (1980 to 17 January 2014). We placed no restrictions on the language or date of publication when searching the electronic databases. We included any randomised controlled trial (RCT) comparing osseointegrated dental implants of different materials, shapes and surface properties having a follow-up in function of at least one year. Outcome measures were success of the implants, radiographic peri-implant marginal bone levels changes and incidence of peri-implantitis. At least two review authors independently conducted screening, risk of bias assessment and data extraction of eligible trials in duplicate. We expressed results using fixed-effect models (if up to three studies were present in a meta-analysis) or random-effects models (when there were more than three studies) using mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI). We reported the following endpoints: one, three, five and 10 years after functional loading. We identified 81 different RCTs. We included 27 of these RCTs, reporting results from 1512 participants and 3230 implants in the review. We compared 38 different implant types with a follow-up ranging from one to 10 years. All implants were made of commercially pure titanium or its alloys, and had different shapes and surface preparations. We judged two trials to be at low risk of bias, 10 to be at unclear risk of bias and 15 to be at high risk of bias. On a 'per participant' rather than 'per implant' basis, we found no significant differences between various implant types for implant failures. The only observed statistically significant difference for the primary objective regarded more peri-implant bone loss at Nobel Speedy Groovy implants when compared with NobelActive implants (MD -0.59 mm; 95% CI -0.74 to -0.44, different implant shapes). The only observed statistically significant difference for the secondary objective was that implants with turned (smoother) surfaces had a 20% reduction in risk to be affected by peri-implantitis than implants with rough surfaces three years after loading (RR 0.80; 95% CI 0.67 to 0.96). There was a tendency for implants with turned surfaces to fail early more often than implants with roughened surfaces. Based on the results of the included RCTs, we found no evidence showing that any particular type of dental implant had superior long-term success. There was limited evidence showing that implants with relatively smooth (turned) surfaces were less prone to lose bone due to chronic infection (peri-implantitis) than implants with much rougher surfaces (titanium-plasma-sprayed). These findings were based on several RCTs, often at high risk of bias, with few participants and relatively short follow-up periods.

Implant-based factor as possible risk for peri-implantitis

Peri-implantitis is currently a topic of major interest in implantology. Considered one of the main reasons of late implant failure, there is an emerged concern whether implant characteristics could trigger inflammatory lesion and loss of supporting bone. The purpose of this narrative review is to provide an evidence based overview on the influence of implant-based factors in the occurrence of peri-implantitis. A literature review was conducted addressing the following topics: implant surface topography; implant location; occlusal overload; time in function; prosthesis-associated factors (rehabilitation extension, excess of cement and implant-abutment connection); and metal particle release. Although existing data suggests that some implant-based factors may increase the risk of peri-implantitis, the evidence is still limited to consider them a true risk factor for peri-implantitis. In conclusion, further evidences are required to a better understanding of the influence of implant-based factors in the occurrence of peri-implantitis. Large population-based studies including concomitant analyses of implant- and patient-based factors are required to provide strong evidence of a possible association with peri-implantitis in a higher probability. The identification of these factors is essential for the establishment of strategies to prevent peri-implantitis.