The relationship between the interleukin-1 periodontal genotype and implant loss. Initial data

The role of cigarette smoking in periodontal disease and treatment outcomes of dental implant therapy

Tobacco smoking has been implicated in periodontal pathology through various mechanisms, including perturbations of the inflammatory and host responses to putative periodontal pathogens, alterations in the subgingival microbial communities, and a compromised healing potential of the tissues leading to imbalance of tissue homeostasis. This review provides the evidence for the relationship between cigarette smoking and periodontal disease in an attempt to explain possible mechanisms of how tobacco smoking may exert its negative effects on the periodontal tissues via systemic and localized pathways. Early and more recent studies explore cigarette smoking-induced changes in periodontal clinical indices; in subgingival microbial flora by employing traditional detection methods for selected microorganisms, in addition to modern techniques such as deep sequencing and bioinformatics analyses that are able to fully characterize the microbial communities; and in inflammatory and immune responses critically appraising study limitations and differences in study protocol designs. Periodontal treatment outcomes and implant therapy outcomes are reviewed in an attempt to shed light on possible mechanisms for the inferior treatment outcome noted in smokers. The potential harmful effects of passive smoking are also reviewed, providing evidence for the advantages of smoking cessation. Quitting cigarette smoking should be recommended by the dentist, and effort should be made to inform smokers about the negative effects of smoking on the periodontal status and implant therapy outcomes.

Association between Interleukin-1 Polymorphisms and Susceptibility to Dental Peri-Implant Disease: A Meta-Analysis

Background and objective: Interleukins (ILs), as important biochemical mediators, control the host response to inflammation and are associated with bone resorption. In the present meta-analysis, we investigated the association between IL−1 polymorphisms and susceptibility to dental peri-implant disease (PID). Materials and methods: We searched Web of Science, Cochrane Library, Scopus, and PubMed/Medline databases for studies published until 9 September2021, without any restrictions. We calculated the crude OR and 95% confidence intervals (CI) to estimate the associations between IL−1 polymorphisms and PID risk in the five genetic models. We further performed the subgroup analysis, sensitivity analysis, meta-regression, trial sequential analysis, and calculated the publication bias. Results: Out of 212 retrieved records, sixteen articles were used in the meta-analysis. There was no association between IL−1A (–889), IL−1B (−511), IL−1B (+3953), and IL−1RN (VNTR) polymorphisms and the risk of dental PIDs, but there was an increased risk of IL−1B (+3954) in the patients with PIDs. In addition, an association of the composite genotype of IL−1A (−889)/IL−1B (+3953) was observed with the risk of PIDs, but not for the composite genotype of IL−1A (−889)/IL−1B (+3954). The publication year, the ethnicity, sample size, and the outcome were significantly influenced pooled estimates of some genetic models. Trial sequential analysis showed the lack of sufficient sample sizes in the studies. Conclusions: Among IL−1 polymorphisms evaluated in the meta-analysis, the composite genotype of IL−1A (−889)/IL−1B (+3953) and IL−1B (+3954) were the only polymorphisms associated with the risk of PID. The T allele and CT genotype of IL−1B (+3954) polymorphism were also associated with an elevated risk of PID.

Association of interleukin-1 gene polymorphism and early crestal bone loss around submerged dental implants: A systematic review and meta-analysis

Aim:

Early crestal bone loss (ECBL) has been observed regardless of the absence of possible etiologic factors for bone loss during the healing phase and before the second-stage implant surgery. The purpose of this systematic review and meta-analysis was to correlate the possible association of interleukin-1 (IL-1) gene polymorphisms and ECBL (bone loss before the second-stage surgery) around dental implants.

Settings and Design:

Systematic review and meta-analysis following PRISMA guidelines.

Materials and Methods:

Considering the inclusion criteria, an electronic search by using specific keywords of three databases PubMed [(“Dental” OR “oral”) AND (“Implants*”) AND (“gene polymorphism” OR “genotype” AND (“IL-1” OR “interleukins”)], Cochrane library [implant AND (biomarker or cytokine), interleukin-1 or IL-1 AND implants], and EMBASE [(“gene polymorphisms”/de OR “interleukins”/cytokine exp OR “biomarker”:ti,ab,kw) AND (“dental implantation”/de OR “oral implant”)] and manual search from 1995 till March 2020 was made by 2 independently calibrated reviewers. ACROBAT-NRSI, Version 1.0.0 and Review Manager, Version 5.3, computer software were used for the risk of bias assessment and to conduct the meta-analysis respectively.

Statistical Analysis Used:

Cochran's Q test and I² statistics.

Results:

Of 38 articles which were found eligible for full-text screening, two articles fulfilled the inclusion criteria and hence were included in the meta-analysis. The I² statistic and Q-test values of the included studies revealed acceptable homogeneity for studied three IL-1 gene polymorphisms (IL-1A−889: I² =0%, IL-1B − 511: I² = 0%, IL-1B+3954: I² = 24%). Forest plot of association between IL-1B−511 gene and ECBL revealed a significant association between 2/2 genotype of IL-1B−511 gene and an increased risk of ECBL (OR = 0.23, 95% CI = 0.09–0.58, P_{heterogeneity}= 0.68, I² = 0%, and P = 0.002). Results of the IL-1A−889 and IL-1B+3954 gene revealed no significant associations between any genotype of these genes with risk of ECBL.

Conclusions:

There is an evidence of the association of IL-1B−511 (2/2) genetic polymorphisms and increased ECBL in the individuals of Asian ethnicity (OR = 0.23, P = 0.002).

Association of IL-10 and TNF-α Polymorphisms with Dental Peri-Implant Disease Risk: A Meta-Analysis, Meta-Regression, and Trial Sequential Analysis

Genetic susceptibility has been reported to be an important risk factor for peri-implant disease (PID). The aim of this meta-analysis was to assess the association between TNF-α and IL-10 polymorphisms and PID susceptibility. The Web of Science, Cochrane Library, Scopus, and PubMed/Medline databases were searched for studies published until 12 April 2021. RevMan 5.3, CMA 2.0, SPSS 22.0, and trial sequential analysis software were used. Twelve studies were included in our analysis. The pooled ORs for the association of TNF-α (−308 G > A), IL-10 (−1082 A > G), IL-10 (−819 C > T), and IL-10 (−592 A > C) polymorphisms were 1.12, 0.93, 1.35, and 0.77 for allelic; 1.42, 0.95, 3.41, and 0.34 for homozygous; 1.19, 1.88, 1.23, and 0.49 for heterozygous, 1.53, 1.12, 1.41, and 0.39 for recessive; and 1.16, 1.87, 2.65, and 0.75 for dominant models, respectively, with all the estimates being insignificant. The results showed an association between TNF-α (−308 G > A) polymorphism and the risk of PID in patients of Asian ethnicity (OR = 1.59; p = 0.03). The present meta-analysis illustrated that TNF-α (−308 G > A), IL-10 (−1082 A > G), IL-10 (−819 C > T), and IL-10 (−592 A > C) polymorphisms were not associated with the risk of PID, whereas TNF-α (−308 G > A) polymorphism was associated with an elevated risk of PID in Asian patients.

Weighted gene co-expression network analysis (WGCNA) to explore genes responsive to Streptococcus oralis biofilm and immune infiltration analysis in human gingival fibroblasts cells

The correlation between oral bacteria and dental implants failure has been reported. However, the effect and mechanism of bacteria during dental implants is unclear. In this study, we explored key genes and candidate gene clusters in human gingival fibroblasts (HGF) cells in response to Streptococcus oralis biofilm through weighted gene co-expression network analysis (WGCNA) and differential genes analysis using gene expression matrix, GSE134481, downloaded from the Gene Expression Omnibus (GEO) database. We obtained 325 genes in the module significantly associated with S. oralis infection and 113 differentially expressed genes (DEGs) in the S. oralis biofilm; 62 DEGs indicated significant correlation with S. oralis injury. Multiple immune pathways, such as the tumor necrosis factor (TNF) signaling pathway, were considerably enriched. We obtained a candidate genes cluster containing 12 genes – IL6, JUN, FOS, CSF2, HBEGF, EDN1, CCL2, MYC, NGF, SOCS3, CXCL1, and CXCL2; we observed 5 candidate hub genes associated with S. oralis infection – JUN, IL6, FOS, MYC, and CCL2. The fraction of macrophage M0 cells was significantly increased in biofilm treatment compared with control; expression of FOS and MYC was significantly positively correlated with macrophage M0 cells. Our findings present a fierce inflammation changes in the transcript level of HGF in response to S. oralis.

Genetic Involvement in Dental Implant Failure: Association With Polymorphisms of Genes Modulating Inflammatory Responses and Bone Metabolism

Implant loss is the most serious complication of dental implants. Although the problems and causes behind the implant failure are clearly defined today, determination of the underlying causes of failure varies by the case. The clusterization phenomenon of implant loss (multiple implant failures) implies the existence of genetic risk factors. Inflammation has a critical effect on osseointegration and implant success. Peri-implantitis is an inflammatory disease of tissue supporting the tooth or implant. Inflammation leads to loss of support tissue, particularly bone, resulting in failure of implants. A single nucleotide polymorphism (SNP) of pro-inflammatory mediator genes may affect their expression levels or amino acid sequence, and, consequently, the host inflammatory response. Since the end of the past century, many studies have been conducted to investigate the association of SNP with implant failure and related conditions. Involvement of several groups of genes-including interleukins, tumor necrosis factor-α, matrix metalloproteinases, and growth factors involved in immune regulation, inflammatory response, and bone metabolism-has been explored. Some have been found to be associated with implant loss and considered potential genetic risk factors for implant failure. In this review, we summarize results of recent studies of impact of genetic factors on dental implant failure.

Analysis of the association of IL4 polymorphisms with orthodontic mini-implant loss

The aim of this study was to investigate the association of clinical characteristics and IL4 tag single nucleotide polymorphisms (SNPs; rs2227284 and rs2243268) with orthodontic mini-implant (MI) failure. The sample included 135 subjects of both sexes, mean age 48.7±10years (range 20-76years): 104 in the control group (patients without any MI loss) and 31 in the study group (patients presenting ≥1 MI loss). Genotypes were determined by real-time PCR. Bivariate and multivariate analyses were performed (P<0.05). No association was found between the selected tag SNPs and MI loss. The C allele of the IL4 rs2243268 polymorphism in the recessive model was more frequent in patients who had fewer MIs installed (≤2 vs. >2; P=0.043, odds ratio 0.65, 95% confidence interval 0.58-0.74). On multivariate analysis, smoking habit was significantly associated with the group with multiple MIs installed (P=0.036), however the significance of the association with rs2243268 was not maintained. No association was found between the socio-demographic, smoking, or genetic factors studied and MI loss. This study supports the interaction between host and environmental factors and its influence on susceptibility to orthodontic MI failure.

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 role of IL-1 gene polymorphisms (IL1A, IL1B, and IL1RN) as a risk factor in unsuccessful implants retaining overdentures

PURPOSE

Implant-supported overdentures are an alternative predictable rehabilitation method that has a high impact on improving the patient's quality of life. However, some biological complications may interfere with the maintenance and survival of these overdenture implants. The goal of this article was to assess the factors that affect peri-implant success, through a hypothetical prediction model for biological complications of implant overdentures.

METHODS

A retrospective observational, prevalence study was conducted in 58 edentulous Caucasian patients rehabilitated with implant overdentures. A total of 229 implants were included in the study. Anamnestic, clinical, and implant-related parameters were collected and recorded in a single database. "Patient" was chosen as the unit of analysis, and a complete screening protocol was established. The data analytical study included assessing the odds ratio, concerning the presence or absence of a particular risk factor, by using binary logistic regression modeling. Probability values (p values) inferior to 0.05 were considered as representing statistically significant evidence.

RESULTS

The performed prediction model included the following variables: mean probing depth, metal exposure, IL1B_allele2, maxillary edentulousness, and Fusobacterium nucleatum. The F. nucleatum showed significant association with the outcome. Introducing a negative coefficient appeared to prevent complications or even boost the biological defense when associated with other factors.

CONCLUSIONS

The prediction model developed in this study could serve as a basis for further improved models that would assist clinicians in the daily diagnosis and treatment planning practice of oral rehabilitation with implant overdentures.

Association of interleukin 4 gene polymorphisms with dental implant loss

PURPOSE

The purpose of this study was to investigate the association between interleukin 4 (IL4) polymorphisms/haplotypes and dental implant loss.

MATERIALS AND METHODS

Two hundred and seventy eight (n = 278) unrelated patients were divided into 2 groups: (1) control group (C) composed of 186 individuals presenting at least 1 osseointegrated implant and (2) study group (S) composed of 94 individuals presenting at least 1 implant loss. After DNA collection, IL4 polymorphisms were investigated by polymerase chain reaction (PCR)-restriction fragment length polymorphism and for the variable number of tandem repeat (VNTR) only by PCR.

RESULTS

No association between alleles/genotypes of -590 (C/T) (P = 0.9704/P = 0.5992) and VNTR (P = 0.7155/P = 0.8789) polymorphisms and implant loss were found between the groups. Regarding +33 (C/T) polymorphism, no difference was found in genotype frequency (P = 0.1288), but the C allele was associated with implant loss (P = 0.0236, odds ratio = 1.61, 95% confidence interval = 1.1-2.4). Haplotype analysis showed no statistical differences between the groups.

CONCLUSION

The C allele of the +33 (C/T) polymorphism in the IL4 gene was associated with susceptibility to dental implant loss in Brazilians in the studied population.

Treatment of Orally Handicapped Edentulous Older Adults Using Dental Implants

The oral handicap of complete edentulism is the terminal outcome of a multifactorial process involving biological factors and patient-related factors. Fully edentulous orally handicapped older adults have been neglected because removable acrylic dentures have been the classic therapy for complete edentulism but are only rehabilitative, not therapeutic. Not replacing missing teeth with stable dentures could prevent adequate food intake. Osseointegrated endosseous implants used as a therapeutic adjunct can reduce the problem of long-term bone resorption to less than 0.1 mm per year. Implant-borne prostheses substantially increase the overall health and quality of life of orally handicapped fully edentulous older adults.

Indications and contraindications of dental implants in medically compromised patients: update

The aim of this study was to review the current scientific literature in order to analyse the indications and contraindications of dental implants in medically compromised patients. A reference research was carried out on PubMed using the key words “implant” AND (oral OR dental) AND (systemic disease OR medically compromised), in articles published between 1993 and 2013. The inclusion criteria were the following: clinical studies in which, at least, 10 patients were treated, consensus articles, reviewed articles and meta-analysis performed in humans treated with dental implants, and which included the disease diagnosis. A total of 64 articles were found, from which 16 met the inclusion criteria. Cardiac systemic diseases, diabetic endocrine pathologies or controlled metabolic disorders do not seem to be a total or partial contraindication to the placement of dental implants. Tobacco addiction, and head and neck radiotherapy are correlated to a higher loss of dental implants. Patients suffering from osteoporosis undergoing biphosphonates therapy show an increased risk of developing bone necrosis after an oral surgery, especially if the drugs are administered intravenously or they are associated to certain concomitant medication.

Key words:Dental implants, medically compromised patient, systemic diseases.

IL1 gene polymorphisms and unsuccessful dental implants

OBJECTIVES

This study aimed to analyse the association between polymorphisms in the IL1 gene cluster and failure of dental implants in a Portuguese population.

MATERIAL AND METHODS

A total of 155 Caucasian Portuguese subjects were divided into two groups: 100 with successful dental implants and 55 with unsuccessful dental implants. DNA was obtained through an oral mucosa scraping. PCR was used to identify the polymorphisms: single nucleotide changes in positions -889 of IL1A gene and +3953 of IL1B gene.

RESULTS

The prevalence of the polymorphisms -889IL1A gene and +3953IL1B gene, determined by the positive result of TGP (Genetic Test for Periodontitis; CGC, Genetics, Portugal), in the studied population rehabilitated with dental implants was of 33.50%. Allele 1 of the IL1B gene was the most prevalent (62.20%), followed by allele 1 of the IL1A gene (54.80%) and the least frequent was allele 2 of IL1B gene (37.40%). Success of dental implants was mainly associated with a negative TGP result, whereas no success was found to be related to a positive result. There were no statistically significant differences between the alleles 1 and 2 of the genes IL1A and IL1B and the tobacco and alcohol consumption for the success or no success of the dental implants.

CONCLUSIONS

The alleles 1 and 2 of IL1A gene and the alleles 1 and 2 of IL1B gene were statistically associated with the success or no success of the dental implants. Tobacco habit and alcohol consumption showed no statistically significant association with success or no success of the dental implants.

The effect of smoking on early bone remodeling on surface modified Southern Implants®

INTRODUCTION

Smoking affects the survival of turned titanium implants. Although smoking has less impact on the failure rate of rough surface implants, the effect on bone loss on rough surface implants has not been studied yet and may be an important factor in biological stability.

AIM

To determine the effect of smoking on early implant failures and bone remodeling around moderately rough implants (Southern Implants®, Southern Implants, Irene, South Africa).

MATERIALS AND METHODS

Three hundred twenty-nine patient records, containing information on 712 installed implants, were scrutinized retrospectively and periapical radiographs were analyzed for interproximal bone level. Mann-Whitney U-test and Fisher's exact test were performed to compare bone level and implant survival in smokers and nonsmokers. Only implants with at least 6 months of function time were analyzed for bone level changes.

RESULTS

The overall survival rate was 98.3%. Implants in smokers had a threefold higher failure rate compared with nonsmokers (5/104 = 4.8% vs 7/608 = 1.2%). This was statistically significant on implant level (p = .007) but not on patient level (1/41 vs 7/288, p = .997). Readable radiographs from 363 implants in 169 patients were available with a mean follow-up of 12 months (SD 5.11; range 6-28). The mean interproximal bone level was 1.36 mm (n = 363; SD 0.41; range 0.48-3.70). Bone levels were independent of jaw location. Sixty implants from 21 smokers lost statistically significantly (p = .001) more bone (mean 1.56; SD 0.53; range 0.75-3.22) than the 303 implants in 148 nonsmokers (mean 1.32 mm; SD 0.38; range 0.48-3.7). The maxilla is especially prone to bone loss compared with the mandible (1.70 mm vs 1.26 mm, p < .001).

CONCLUSION

The Southern Implants® system demonstrated a high absolute survival rate. Although smokers are not more prone to implant loss, more pronounced peri-implant bone loss was observed, especially in the maxilla. Whether this affects future biological complications remains to be investigated in prospective long-term studies.

Association of the composite IL-1 genotype with peri-implantitis: a systematic review

OBJECTIVE

Cytokine gene polymorphisms may modulate the host response to the bacterial challenge and influence susceptibility to peri-implantitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A (-889) and in IL-1B (+3953), and peri-implantitis.

MATERIAL AND METHODS

An electronic search in the National Library of Medicine-computerized bibliographic database MEDLINE and a manual search were performed. The search was conducted for longitudinal clinical trials comparing progression of peri-implantitis in IL-1 genotype positive (carrying allele 2) with IL-1 genotype negative (not carrying allele 2) subjects. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 44 titles of which two longitudinal publications were included.

CONCLUSION

Based on the findings from this study, there is not enough evidence to support or refute an association between the IL-1 genotype status and peri-implantitis. Systematic genetic testing for the assessment of the risk of peri-implantitis cannot be recommended as a standard of care at this time.

5-year clinical experience with BTI dental implants: risk factors for implant failure

OBJECTIVES

The aims of this study were to identify with appropriate statistical tests the risk factors associated with implant failure and to evaluate the long-term survival of dental implants using implant loss as an outcome variable and performing an implant-, surgery- and patient-based analysis of failures.

MATERIAL AND METHODS

A retrospective cohort study design was used. One thousand sixty patients received 5787 BTI implants during the years of 2001-2005 in Vitoria, Spain. The potential influence of demographic items, clinical items, surgery-dependent items and prosthetic variables on implant survival was studied. Implant survival was analysed using a life-table analysis. Cox proportional hazards regression was used to identify risk factors related to implant failure.

RESULTS

Smoking habits, implant position, implant staging (two-stage implants) and the implementation of special techniques were statistically correlated with lower implant survival rates. Two risk factors associated with implant failure were detected in this study: implant staging (two-stage implants) and the use of special techniques. Additionally, the overall survival rates of BTI implants were 99.2%, 96.4% and 96% for the implant-, surgery- and patient-based analysis, respectively. Totally, 28 out from 5787 implants (0.48%) were lost during the observation period. Most of the patients with implant failure (69.6%) presented chronic or aggressive periodontitis.

CONCLUSIONS

Implant staging and the use of special techniques are risk factors for implant failure.

A comprehensive and critical review of dental implant prognosis in periodontally compromised partially edentulous patients

OBJECTIVES

The outcome of implant treatment in periodontally compromised partially edentulous patients has not been completely clarified. Therefore, the aim of the present study was to perform, applying a systematic methodology, a comprehensive and critical review of the prospective studies published in English up to and including August 2006, regarding the short-term (<5 years) and long-term (>or=5 years) prognosis of osseointegrated implants placed in periodontally compromised partially edentulous patients.

MATERIAL AND METHODS

Using The National Library Of Medicine and Cochrane Oral Health Group databases, a literature search for articles published up to and including August 2006 was performed. At the first phase of selection the titles and abstracts and at the second phase full papers were screened independently and in duplicate by the three reviewers (I. K. K., S. K., I. F.).

RESULTS

The search provided 2987 potentially relevant titles and abstracts. At the first phase of evaluation, 2956 publications were rejected based on title and abstract. At the second phase, the full text of the remaining 31 publications was retrieved for more detailed evaluation. Finally, 15 prospective studies were selected, including seven short-term and eight long-term studies. Because of considerable discrepancies among these studies, meta-analysis was not performed.

CONCLUSIONS

No statistically significant differences in both short-term and long-term implant survival exist between patients with a history of chronic periodontitis and periodontally healthy individuals. Patients with a history of chronic periodontitis may exhibit significantly greater long-term probing pocket depth, peri-implant marginal bone loss and incidence of peri-implantitis compared with periodontally healthy subjects. Even though the short-term implant prognosis for patients treated for aggressive periodontitis is acceptable, on a long-term basis the matter is open to question. Alterations in clinical parameters around implants and teeth in aggressive periodontitis patients may not follow the same pattern, in contrast to what has been reported for chronic periodontitis patients. However, as only three studies comprising patients treated for aggressive periodontitis were selected, more studies, specially designed, are required to evaluate implant prognosis in this subtype of periodontitis. As the selected publications exhibited considerable discrepancies, more studies, uniformly designed, preferably longitudinal, prospective and controlled, would be important.

Smoking interferes with the prognosis of dental implant treatment: a systematic review and meta-analysis

AIM

This systematic literature review was performed to investigate if smoking interferes with the prognosis of implants with and without accompanying augmentation procedures compared with non-smokers.

METHODS

A systematic electronic and handsearch (articles published between 1989 and 2005; English and German language; search terms "dental or oral implants and smoking"; "dental or oral implants and tobacco") was performed to identify publications providing numbers of failed implants, related to the numbers of smokers and non-smokers for meta-analysis. Publications providing statistically examined data of implant failures or biologic complications among smokers compared with non-smokers were included for systematic review.

RESULTS

Of 139 publications identified, 29 were considered for meta-analysis and 35 for systematic review. Meta-analysis revealed a significantly enhanced risk for implant failure among smokers [implant-related odds ratio (OR) 2.25, confidence interval (CI(95%)) 1.96-2.59; patient-related OR 2.64; CI(95%) 1.70-4.09] compared with non-smokers, and for smokers receiving implants with accompanying augmentation procedures (OR 3.61; CI(95%) 2.26-5.77, implant related). The systematic review indicated significantly enhanced risks of biologic complications among smokers. Five studies revealed no significant impact of smoking on prognosis of implants with particle-blasted, acid-etched or anodic oxidized surfaces.

CONCLUSION

Smoking is a significant risk factor for dental implant therapy and augmentation procedures accompanying implantations.

The association of the composite IL-1 genotype with periodontitis progression and/or treatment outcomes: a systematic review

BACKGROUND

Genetically transmitted traits such as cytokine gene polymorphisms may accentuate the host inflammatory response to the bacterial challenge and influence susceptibility to periodontitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A-889 and in IL-1B +3953, and periodontitis progression and/or treatment outcomes.

MATERIAL AND METHODS

Based on the focused question, a search was conducted for longitudinal clinical trials comparing progression of periodontitis and/or treatment outcomes in IL-1 genotype-positive (carrying allele 2) and IL-1 genotype-negative (not carrying allele 2) subjects. A search in the National Library of Medicine computerized bibliographic database MEDLINE and a manual search were performed. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 122 titles of which 11 longitudinal publications were included. The heterogeneity of the data prevented the performance of a meta-analysis. While findings from some publications rejected a possible role of IL-1 composite genotype on progression of periodontitis after various therapies, other reported a prognostic value for disease progression of the positive IL-1 genotype status. When assessed on a multivariate risk assessment model, several publications concluded that the assessment of the IL-1 composite genotype in conjunction with other covariates (e.g. smoking and presence of specific bacteria) may provide additional information on disease progression. The small sample size of the available publications, however, requires caution in the interpretation of the results.

CONCLUSION

Based on these findings, (i) there is insufficient evidence to establish if a positive IL-1 genotype status contributes to progression of periodontitis and/or treatment outcomes. Therefore, (ii) results obtained with commercially available tests should be interpreted with caution.

Effect of Tumor Necrosis Factor-α Gene Polymorphism on Peri-Implant Bone Loss Following Prosthetic Reconstruction

PURPOSE

The present study investigates the association between a specific polymorphism in the tumor necrosis factor (TNF)-alpha gene, consisting of allele 2 of TNF-alpha-308, and peri-implant bone loss following prosthetic reconstruction.

MATERIALS AND METHODS

This case-control study included 36 patients (20 women, 16 men; mean age 46 years) who had used implant-supported prostheses for a minimum of 6 months and a maximum of 31 months. The patients were nonsmoking, white Caucasian Brazilians, in good general health, and were not receiving medication. In the case group, patients exhibited 1 or more implants with a diagnosis of peri-implant bone loss following prosthetic reconstruction; control patients had 1 or more healthy implants.

RESULTS

Polymorphism in the TNF-alpha gene, allele 2 of TNF-alpha, was not associated with an increased risk for peri-implant bone loss following prosthetic reconstruction (P=0.19; chi2=1.71; df=1), although 21.1% of the subjects carried allele in the control group 2, and 41.2% carried allele 2 in the case group.

CONCLUSIONS

Polymorphism in allele 2 of the TNF-alpha-308 gene is not associated with an increased risk for peri-implant bone loss following prosthetic reconstruction. However, further studies based on a greater number of patients are necessary.

Medical Contraindications to Implant Therapy: Part II: Relative Contraindications

Systemic conditions and habits influence dental implant survival to varying degrees. Illnesses that impair the normal healing cascade worsen surgical success. The mere presence of a disease, however, does not necessarily preclude implant therapy or affect significantly long-term outcomes. Certain disorders, when controlled, or other situations allow implant survival rates that match those in health. This paper reviews these relative contraindications, which include adolescence, aging, osteoporosis, smoking, diabetes, positive interleukin-1 genotype, human immunodeficiency virus positivity, cardiovascular disease, and hypothyroidism.

IL-1RN gene polymorphism is associated with peri-implantitis

OBJECTIVES

Interleukin (IL)-1alpha, IL-1beta and their natural specific inhibitor IL-1 receptor antagonist (IL-1ra) play a key role in the regulation of the inflammatory response in periodontal tissues. Polymorphisms in the IL-1 gene cluster have been associated with severe adult periodontitis. We aimed to investigate the IL-1 gene cluster polymorphisms in patients with peri-implantitis.

MATERIAL AND METHODS

The study included 120 North Caucasian individuals. A total of 71 patients (mean age 68 years, 76% smokers) demonstrating peri-implantitis at one or more implants as evidenced by bleeding and/or pus on probing and bone loss amounting to >3 threads on Brånemark implants and 49 controls (mean age 66 years, 45% smokers) with clinical healthy mucosa and no bone loss around the implants were recruited for the study. The titanium implants, ad modum Brånemark, had been in function for at least 2 years. Mouthwash samples were collected and used for genotyping of the bi-allelic polymorphisms IL-1A(-889), IL-1B(+3953), IL-1B(-511) and a variable number of tandem repeat IL-1RN gene polymorphisms using PCR technique.

RESULTS

Significant differences were found in the carriage rate of allele 2 in the IL-1RN gene between peri-implantitis patients and controls (56.5% vs. 33.3%, respectively; odds ratios (OR) 2.6; 95% confidence interval (CI) 1.2-5.6; P=0.015). Logistic regression analysis taking smoking, gender and age into account confirmed the association between the IL-1RN allele 2 carriers and peri-implantitis (OR 3; 95% CI 1.2-7.6; P=0.02).

CONCLUSIONS

Our results provide evidence that IL-1RN gene polymorphism is associated with peri-implantitis and may represent a risk factor for this disease.

Nine- to fourteen-year follow-up of implant treatment. Part I: implant loss and associations to various factors

OBJECTIVES

The aim of the present study was to evaluate the long-term result of implant therapy, using implant loss as outcome variable.

MATERIAL AND METHOD

Two hundred and ninty-four patients had received implant therapy (Brånemark System) during the years of 1988-1992 in Kristianstad County, Sweden. The patients were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 9-14 years after implant placements, the patients were again called in for a complete clinical and radiographic examination.

RESULTS

Two hundred and eighteen patients treated with 1057 implants were examined. Twenty-two patients had lost 46 implants and 12 implants were considered "sleeping implants". The overall survival rate was 95.7%. Implant loss appeared in a cluster in a few patients and early failures were most common. Eight patients lost more than one fixture. A significant relationship was observed between implant loss and periodontal bone loss of the remaining teeth at implant placement. Maxillary, as opposed to mandibulary implants, showed more implant loss if many implants were placed in the jaw. A significant relationship between smoking habits and implant loss was not found.

CONCLUSION

A history of periodontitis seems to be related to implant loss.

Mikrobiologische Untersuchung zur Ermittlung des Erfolges der Sofortimplantation im parodontal geschädigten Gebiss

AIM

The aim of the present study was to investigate the prevalence of periodontal marker organisms and specific interleukin-1 (IL-1) gene polymorphisms (which show a close association with periodontitis) and their effect on the success of immediate implant placement postextraction in the patient with periodontal disease.

PATIENTS AND METHODS

A group of 59 patients (22 men and 37 women aged 20-81 years, median age 55 years, 18 smokers) with chronic adult periodontitis participated in the study which included a 1-year observation period postoperatively. Prior to tooth extraction two DNA samples were obtained for the microbiological diagnosis of five anaerobic gram-negative pathogens (Haemophilus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia sensu stricto, Treponema denticola) and to identify the IL-1 gene polymorphisms. Patients were treated with a total of 95 immediate dental implants (26 Ankylos/Friadent and 69 Camlog Root-Line/Camlog Biotechnologies) placed into extraction sites, 78 of which were loaded immediately. After 1 year four failures were observed; all of these patients were smokers.

RESULTS

None of these patients showed a positive IL-1 genotype; periodontal marker organisms were only found in one patient. No significant difference was seen in the microbiological pathogens between smokers and nonsmokers. Of 59 patients, 23 (39%) tested positive for IL-1 genotype polymorphism. Smoking was shown to increase the risk of implant failure. No association was observed between failures and the IL-1 gene polymorphisms or pathogens.

CONCLUSION

In conclusion, our study shows that periodontally infected sites do not seem to be a contraindication for immediate implantation.

Early colonization of non-submerged dental implants in patients with a history of advanced aggressive periodontitis

The aim of the study was to evaluate the early colonization of non-submerged implants over a 6-month period in partially edentulous patients treated for advanced aggressive periodontal disease. In 22 patients treated for advanced aggressive periodontitis and in a supportive maintenance program for a period between 12 and 240 months at implant surgery, a total of 68 non-submerged dental implants were installed. Patients had a plaque score below 20%, and less than 20% of the pockets around the teeth were bleeding on probing (BOP). Using DNA-probes (micro-IDent), the presence and concentration of five periodontal pathogens (Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythensis (Tf) and Treponema denticola (Td)) were determined in the five deepest pockets of the rest dentition pre-operatively and after 6 months as well as five places around each implant 10 days, 1 month, 3 months and 6 months after surgery. In each patient, a test to determine the genotype interleukin-1 (IL-1) was performed (PST - micro-IDent). After 6 months, no difference in microbial composition as compared with baseline was found around the teeth in five patients, in 12 minute differences and in five patients important differences were observed. Ten days after surgery, three patients had a complete similar bacterial composition between teeth and implants. In 14 patients, the composition was fairly similar, while large differences in composition and concentration occurred in five patients. This microbiota around the implants remained almost unchanged over a 6-month period and did not hamper the clinical and radiographic osseointegration and did not lead to peri-implantitis, mucositis or initiation of bone destruction.

Evaluation of the relationship between interleukin-1 gene cluster polymorphisms and early implant failure in non-smoking patients

OBJECTIVE

The aim of the present study was to investigate the relationship between specific polymorphisms of the interleukin-1 gene cluster and the early failure of osseointegrated implants.

MATERIAL AND METHODS

The subject population was composed by a test group comprising 28 non-smoking patients (mean age 52.7) that had suffered one or more early implant failures and by a control group consisting of 34 individuals (mean age 43.3) with one or more healthy implants. Genomic DNA from buccal mucosa was amplified by the polymerase chain reaction (PCR), followed by restriction fragment length polymorphism (RFLP) and submitted to polyacrylamide gel electrophoresis to distinguish the alleles of the interleukin-1A (-889), interleukin-1B (+3953), interleukin-1B (-511) and interleukin-RN (intron 2) gene polymorphisms. Differences in the allele and genotype frequencies between control and test groups were assessed by chi(2) test or by Monte Carlo simulations (P<0.05). Haplotype frequencies, linkage disequilibrium and Hardy-Weinberg equilibrium were also estimated.

RESULTS

No statistically significant differences were found in the genotype distribution or allelic frequencies of the polymorphisms. No differences were observed between control and test groups when different interleukin-1 gene cluster haplotypes were compared. Nevertheless, the interleukin-1A (-889) and interleukin-1B (+3953) polymorphic sites were in strong linkage disequilibrium (P=0.00014 for control group and P=0.0238 for the test group).

CONCLUSION

This study suggests that polymorphisms in the interleukin-1 gene cluster are not associated with early implant failure in a non-smoking Brazilian population.

Implant therapy in partially edentulous, periodontally compromised patients: a review

AIM

The purpose of the present study was to perform a review using a systematic approach to evaluate the long-term (>/=5 years) success of implants placed in partially edentulous patients with a history of periodontitis as evidenced by loss of supporting bone and implant loss.

MATERIAL & METHODS

An electronic search of the National Library of Medicine, Washington DC (Medline-PubMed) was performed using specific search terms to identify studies assessing, in periodontitis patients, the success of implants with regard to bone level outcomes. Search was performed on abstracts registered up to October 2003.

RESULTS

The searches identified 877 abstracts. Titles and abstracts were independently screened by two reviewers (G.A.W. & K.M.B.) to identify publications that met the inclusion criteria. Review of these abstracts resulted in 13 publications for detailed review. These papers were reviewed by the three authors. Finally four papers which met the criteria of eligibility were independently selected by the three reviewers.

CONCLUSION

Based on the limited data, it seems justified to conclude that the outcome of implant therapy in periodontitis patients may be different compared to individuals without such a history as evidenced by loss of supporting bone and implant loss.

Association of interleukin-1 polymorphisms with aggressive periodontitis

BACKGROUND

Genetic polymorphisms for interleukin (IL)-1alpha and -1beta have been proposed as potential genetic markers for periodontal diseases. Since the prevalence of these polymorphisms could be race-related, and no data exist about the frequency of these polymorphisms in the Chilean population, the aim of the current study was to investigate the association of the interleukin-1 gene polymorphisms with aggressive periodontitis (AgP).

METHODS

Thirty-six patients with AgP, 75 healthy controls, and 75 subjects of unknown periodontal status (reference population) were genotyped for the IL-1A -889 and IL-1B +3954 loci, by polymerase chain reaction (PCR) amplification followed by restriction enzyme digestion and gel electrophoresis. Data were analyzed using the chi-square test, calculating odds ratios (OR) and confidence intervals (CI).

RESULTS

The prevalence of the positive composite IL-1 genotype was higher in patients (25%) than in healthy controls (12%), but the difference was not significant (P= 0.14). The IL-1B +3954 homozygous for allele 1 frequency was higher in controls than in patients suggesting a protective factor for AgP. The heterozygous for allele 2 of the IL- 1B showed a significant association with AgP (OR = 2.86, 95% CI 1.06 to 7.71, P= 0.030). No association was observed in localized AgP and generalized AgP between the extent of disease and the presence of the composite positive genotype. Because the number of smokers was too small in patients and in controls, no other analyses were performed.

CONCLUSION

The results of the present study support a positive association between AgP and the presence of the IL-1B +3954 allele 2 polymorphism.

Association of Interleukin-1 Polymorphisms With Periodontal Disease

BACKGROUND

Several studies have investigated genetic polymorphisms for cytokines as potential genetic markers for periodontitis. Some studies have found that interleukin (IL)-1A and IL-1B polymorphisms are associated with a higher severity of periodontitis, while others found no association. The aims of this study were to determine the prevalence of the IL-1A-889 and IL-1B+3954 (previously described as +3953) polymorphisms in Chileans and their association with periodontitis.

METHODS

Subjects aged 20 to 48 were selected from people requesting dental treatment at a public health center in Santiago, Chile. A case-control study of 330 cases of periodontitis patients and 101 healthy controls was performed. A full-mouth periodontal examination was performed on each subject and a structured questionnaire was conducted to determine smoking habits. Cases were categorized as having initial, moderate, or severe periodontitis according to the percentage of sites with clinical attachment loss > or =3 mm. Genomic DNA was analyzed for polymorphism in the IL-1A gene at site -889 and IL-1B gene at site +3954 by polymerase chain reaction (PCR) amplification followed by restriction enzyme digestion and gel electrophoresis. Data were analyzed by chi square test, analysis of variance (ANOVA), and by calculating odds ratio (OR) and 95% confidence intervals (CI).

RESULTS

Demographic and socio-economic characteristics of subjects were similar in cases and in controls. A higher frequency of heterozygous of the IL-1A-889 was found in cases than in controls, but the difference was not significant. The heterozygous of the IL-1B+3954 was significantly higher in cases than in controls and was associated with periodontitis (OR 3.12, 95% CI 1.59 to 6.09, P = 0.001). The homozygous for allele 1 of the IL-1B+3954 was a protective factor for periodontitis (OR 0.35, 95% CI 0.19 to 0.66, P = 0.001). The prevalence of positive genotype (at least one allele 2 present at each locus) was significantly higher in cases (26.06%) than in controls (9.9%) and was significantly associated with periodontitis (OR 3.21, 95% CI 1.60 to 6.44, P = 0.001), irrespective of the smoking status and periodontitis severity. Sensitivity of positive genotype was 26%, the specificity 90%, and the positive predictive value 89%.

CONCLUSION

Within the limits of this study, the results show that individuals carrying the positive genotype have significantly greater risk for developing periodontitis.

Clinical Consequences of IL-1 Genotype on Early Implant Failures in Patients under Periodontal Maintenance

BACKGROUND

Implant failure and biologic complications such as periimplantitis are not completely avoidable. Are there any genetic and microbiologic parameters that could be used to identify patients at risk for implant failure, preferably prior to treatment? This would result in improvement of the diagnostics, treatment decision, and risk assessment.

PURPOSE

The aims of this retrospective study were to describe (1) the absolute failure rate of Brånemark System implants (Nobel Biocare AB, Göteborg, Sweden) consecutively installed over a 10-year period in partially edentulous patients treated for periodontal disease prior to implant treatment and under regular professional maintenance, (2) the rate of interleukin-1 (IL-1) polymorphism in those patients who experienced at least one implant failure during the first year of function, and (3) the prevalence of periodontal pathogens in dental and periimplant sites with and without signs of inflammation.

MATERIAL AND METHODS

Of 766 patients, 81 encountered at least one implant failure; 22 patients were clinically examined and were tested genetically for IL-1 genotypes. The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella nigrescens was analyzed.

RESULTS

The absolute implant survival rate for the whole population was 95.32%; 10.57% of the patients encountered an implant loss. Implant loss in the examined group (n = 22) was 32 of 106 (30.1%); 10 (45%) of the 22 patients were smokers, and 6 (27%) of the 22 patients were IL-1 genotype positive. Patients positive for IL-1 genotype were not more prone to implant loss; however, a significant synergistic effect with smoking was demonstrated. Between patients who were IL-1 genotype positive and those who were IL-1 genotype negative, the differences in regard to bleeding on probing or periodontal pathogens did not reach statistical significance.

CONCLUSION

The overall implant failure rate in a population treated and maintained for periodontal disease is similar to that of healthy subjects. A synergistic effect found between smoking and a positive IL-1 genotype resulted in a significantly higher implant loss. This indicates that further research with a larger patient group should focus on multifactorial analysis for adequate risk assessment.

Analysis of the transforming growth factor-beta 1 gene promoter polymorphisms in early osseointegrated implant failure

Transforming growth factor-beta 1 is a multifunctional cytokine involved in extracellular matrix deposition, reduction of inflammation, and promotion of wound healing. Single nucleotide polymorphisms in the promoter region of human transforming growth factor-beta 1 gene, C-509T and G-800A, have been shown to increase the transcriptional activity of this cytokine and have been associated with a variety of diseases. The objective of this study was to investigate the possible association between these single nucleotide polymorphisms and the early implant failure. A sample of 68 nonsmoking patients was divided into two groups: a test group comprising 28 patients with one or more early failed implants and a control group consisting of 40 individuals with one or more healthy implants. Genomic DNA from oral mucosa was amplified by polymerase chain reaction and analyzed by restriction fragment length polymorphism. The significance of the differences in observed frequencies of single nucleotide polymorphisms was assessed using the chi square test and Fisher's exact test. The cited single nucleotide polymorphisms in transforming growth factor-beta 1 were analyzed in combination as haplotype using the computer program ARLEQUIN. The authors did not observe significant differences in the allele and genotypes to both single nucleotide polymorphisms of transforming growth factor-beta 1 gene (C-509T and G-800A) between control and early implant failure groups. The distribution of the haplotypes arranged as allele and genotypes were similar between control and test groups. These results indicate that C-509T and G-800A polymorphisms in the transforming growth factor-beta 1 gene are not associated separately or in haplotype combinations with early implant failure, suggesting that the presence of those single nucleotide polymorphisms alone do not constitute a genetic risk factor for early implant failure in the Brazilian population.

A review of selected dental literature on evidence-based treatment planning for dental implants: Report of the Committee on Research in Fixed Prosthodontics of the Academy of Fixed Prosthodontics

This literature review summarizes research with the aim of providing dentists with evidence-based guidelines to apply when planning treatment with osseointegrated implants. Peer-reviewed literature published in the English language between 1969 and 2003 was reviewed using Medline and hand searches. Topics reviewed include systemic host factors such as age, gender, various medical conditions, and patient habits, local host factors involving the quantity and quality of bone and soft tissue, presence of present or past infection and occlusion, prosthetic design factors, including the number and arrangement of implants, size and coatings of implants, cantilevers and connections to natural teeth, and methods to improve outcomes of implant treatment in each category. The review demonstrated that there is no systemic factor or habit that is an absolute contraindication to the placement of osseointegrated implants in the adult patient, although cessation of smoking can improve outcome significantly. The most important local patient factor for successful treatment is the quality and quantity of bone available at the implant site. Specific design criteria are provided, including guidelines for spacing of implants, size, materials, occlusion, and fit. Limitations in the current body of knowledge are identified, and directions for future research are suggested.

Impact of IL-1 genotype and smoking status on the prognosis of osseointegrated implants

AIM

This study evaluated the impact of the IL-1 genotype and smoking status on the prognosis and development of complications of osseointegrated implants.

MATERIAL AND METHODS

The clinical charts of 180 consecutively admitted patients were analyzed with respect to the occurrence of biological complications in conjunction with oral implants. Biologic complications were defined as clinical conditions with suppuration from the peri-implant sulcus, development of a fistula or peri-implantitis with radiologic bone loss. All patients had received one or more ITI dental implants, which had been in function for at least 8 (range: 8-15) years. This patient population had received 292 implants. From these, 51 implants in 34 patients showed late (infectious) biologic complications, and 241 implants had survived without any biologic complications at all.

RESULTS

Of the 180 patients, 53 were smokers, who were subdivided in a series of classes according to their intensity of smoking and 127 were never smokers. Sixty-four of 180 (36%) patients tested positive for the IL-1 genotype polymorphism. This prevalence corresponds to previous reports for the prevalence of European descent populations. The results for the non-smoking group indicated no significant correlation between implant complications and a positive IL-1 genotype. However, there was a clear association for heavy smokers between a positive IL-1 genotype and implant complications. 6 of 12 or half of the heavy smokers and IL-1 genotype-positive patients had either an implant failure, i.e. loss of implant, or a biologic complication during the follow-up period.

CONCLUSIONS

These findings have led to the conclusion that there is a synergistic effect between a positive IL-1 genotype and smoking that puts dental implants at a significantly higher risk of developing biologic complications during function.

Early Failure of Dental Implants and TNF-?? (G-308A) Gene Polymorphism

Tumor necrosis factor-alpha (TNF-alpha) is a potent inflammatory mediator with bone resorption activity. Polymorphisms in the promoter region of the human TNF-alpha gene have been shown to affect the levels of this cytokine and have been associated with a variety of diseases. The aim of this study was to investigate the possible relationship between early implant failure and a single nucleotide polymorphism (SNP) in the -308 promoter region of the TNF-alpha gene. A sample of 66 nonsmokers was divided into 2 groups: a test group comprising 28 patients (mean age, 52.7 years) with one or more early failed implants and a control group consisting of 38 individuals (mean age, 43.2 years) with one or more healthy implants. Genomic DNA from buccal mucosa was amplified by the polymerase chain reaction (PCR), analyzed by restriction fragment length polymorphism (RFLP), and submitted to polyacrylamide gel electrophoresis to distinguish allele G and allele A of the TNF-alpha (-308) gene polymorphism. Differences in the allele and genotype frequencies between control and test groups were assessed by chi-squared test (P <0.05). No significant difference was observed in the allele (P = 0.4635) and genotype (P = 0.4445) distribution of the polymorphism when control and failure groups were compared. The results indicate that the TNF-alpha (G-308A) gene polymorphism is not associated with early implant failure, suggesting that its presence alone does not constitute a genetic risk factor for implant loss in the Brazilian population.

Long-term implant prognosis in patients with and without a history of chronic periodontitis: a 10-year prospective cohort study of the ITI Dental Implant System

AIM

The aim of this 10-year study was to compare the failure, success and complication rates between patients having lost their teeth due to periodontitis or other reasons.

MATERIAL AND METHODS

Fifty-three patients who received 112 hollow screw implants (HS) of the ITI Dental Implant System were divided into two groups: group A - eight patients with 21 implants having lost their teeth due to chronic periodontitis; group B - forty five patients with 91 implants without a history of periodontitis. One and 10 years after surgical placement, clinical and radiographic parameters were assessed. The incidences of peri-implantitis were noticed over the 10 years of regular supportive periodontal therapy.

RESULTS

Success criteria at 10 years were set at: pocket probing depth (PPD) <or=5 mm, bleeding on probing (BoP-, bone loss <0.2 mm annually. The survival rate for the group with a past history of chronic periodontitis (group A) was 90.5%, while for the group with no past history of periodontitis (group B) it was 96.5%. Group A had a significantly higher incidence of peri-implantitis than group B (28.6% vs. 5.8%). With the success criteria set, 52.4% in group A and 79.1% of the implants in group B were successful. With a threshold set at PPD <or=6 mm, BoP- and bone loss <0.2 mm annually, the success rates were elevated to 62% and 81.3% for groups A and B, respectively. Relying purely on clinical parameters of PPD <or=5 mm and BoP-, the success rates were at 71.4% and 94.5%, and with a threshold set at PPD <or=6 mm and BoP-, these proportions were elevated to 81% and 96.7% for groups A and B, respectively.

CONCLUSIONS

Patients with implants replacing teeth lost due to chronic periodontitis demonstrated lower survival rates and more biological complications than patients with implants replacing teeth lost due to reasons other than periodontitis during a 10-year maintenance period. Furthermore, setting of thresholds for success criteria is crucial to the reporting of success rates.