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

Apatite-Forming Ability and Visible Light-Enhanced Antibacterial Activity of CuO-Supported TiO2 Formed on Titanium by Chemical and Thermal Treatments

Titanium with apatite-forming ability as well as antibacterial activity is useful as a component of antibacterial dental implants. When Ti was subjected to hydrogen peroxide (H2O2), copper acetate (Cu(OAc)2), and heat (H2O2-Cu(OAc)2-heat) treatments, a network structure of anatase and rutile titanium dioxide (TiO2) and fine copper oxide (CuO) particles was formed on the Ti surface. The resulting samples accumulated a dense and uniform apatite layer on the surface when incubated in simulated body fluid and showed enhanced antibacterial activity against Escherichia coli and Staphylococcus aureus under visible-light irradiation. Electron spin resonance spectra of H2O2-Cu(OAc)2-heat-treated samples showed that hydroxyl radicals (·OH) were generated from the samples, and the concentration of ·OH increased with increasing Cu concentration of the Cu(OAc)2 solution. The enhanced antibacterial activity of these samples under visible-light irradiation may be attributable to the generation of ·OH from samples. These results suggest that Ti implants obtained using H2O2-Cu(OAc)2-heat treatments and subjected to regular or on-demand visible-light irradiation may provide a decreased risk of peri-implantitis.

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.

Small-diameter titanium grade IV and titanium-zirconium implants in edentulous mandibles: Ten-year results from a double-blind, randomised controlled split-mouth core-trial

The goal of this extension study was to compare the 10-year outcome of 3.3 mm diameter titanium-zirconium (TiZr) or grade IV titanium (Ti) implants in mandibular implant-overdentures.

MATERIALS AND METHODS

This study is the 10-year follow-up from a randomised, controlled, double-blind, split-mouth multicentre clinical trial. Patients with edentulous mandibles had received two implants in the interforaminal region (bone-level, diameter 3.3 mm, microrough surface), one of TiZr (test) and one of Ti (control). Implant survival and success, plaque and sulcus bleeding indices, probing pocket depth, gingival margin, clinical attachment level and radiographic crestal bone levels were evaluated.

RESULTS

Fifty of 91 patients with implants were available for the 10-year examination and 36 patients were valid for the intent-to-treat (ITT) analysis. The implant success rate was calculated as 94.6% and 91.9% for the TiZr implants and the Ti implants respectively. Four implants were lost (TiZr = 1; Ti = 3) in the entire study period. Kaplan-Meier survival analyses estimated 10- year implant survival rate for TiZr to 98.9% and Ti 95.8%.The mean of total and functional crestal bone loss was 1.49 mm (±1.37 mm) and 0.82 mm (±1.09 mm) in the TiZr group and 1.56 mm (±1.34 mm) and 0.85 mm (±1.16 mm) in the Ti group.

CONCLUSIONS

This split-mouth design RCT on mandibular implant-overdentures evidenced, bearing in mind its follow-up time-related reduced cohort size, high 10-year implant success- and survival rates. These results confirm TiZr as well-suited implant material for realising small-diameter implants. Registered on www.

CLINICALTRIALS

gov: NCT01878331.

Osseointegration and osteoimmunology in implantology: assessment of the immune sustainability of dental implants using advanced sonographic diagnostics: research and case reports

OBJECTIVE

Bone marrow defects of the jaw (BMDJ) surrounding dental implants, in combination with impaired bone-to-implant contact (BIC), are difficult to detect in X-rays. This study evaluated BMDJ surrounding titanium (Ti-Impl) and ceramic (Cer-Impl) dental implants and incomplete BIC using a new trans-alveolar ultrasonography device (TAU) with numerical scaling for BIC.

METHODS

The titanium stimulation test (Ti-Stim) was used to detect immune overactivation in response to titanium. Bone density surrounding implants was measured using TAU. We also validated osteoimmune dysregulation.

RESULTS

TAU values showed reduced BIC and decreased osseointegration for Ti-Impl. Moreover, TAU values in the Cer-Impl group were more than twice those in the Ti-Impl cohort. The multiplex analysis of C-C motif chemokine 5 (CCL5, also known as RANTES) expression revealed a 20-fold increase in BMDJ surrounding Ti-Impl. Higher levels of CCL5 inflammation were present in the positive Ti-Stim group.

CONCLUSIONS

Our data indicate that Cer-Impl have an osteoimmune advantage over Ti-Impl. The key determinant for osteoimmune sustainability appears to be the absence of inflammation at the implant site. We therefore recommend the use of TAU to assess the implant site prior to implantation.

Limited Evidence Suggests That Increased Frequency Of Daily Cigarette Smoking Might Be Associated With A Minor Increase In The Peri-Implant Bone Loss

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Afshari Z, Yaghini J, Naseri R. Levels Of Smoking and Peri-Implant Marginal Bone Loss: A Systematic Review And Meta-Analysis. J. Evid.-Based Dent. Pract. 2022;22(3):101721.           SOURCE OF FUNDING: None reported.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data (SRM).

Non-Surgical Therapy and Oral Microbiota Features in Peri-Implant Complications: A Brief Narrative Review

The therapeutic discretion in cases of peri-implantitis should take into account the limits and advantages of specific therapeutic itineraries tailored according to each clinical case and each individual patient. This type of oral pathology emphasizes the complex classification and diagnostic issues coupled with the need for targeted treatments, in light of the oral peri-implant microbiota changes. This review highlights the current indications for the non-surgical treatment of peri-implantitis, describing the specific therapeutic efficacy of different approaches and discussing the more appropriate application of single non-invasive therapies The non-surgical treatment choice with antiseptics or antibiotics (single or combined, local, or systemic) for short courses should be considered on a case-by-case basis to minimize the incidence of side effects and concomitantly avoid disease progression.

On Peri-Implant Bone Loss Theories: Trying To Piece Together the Jigsaw

This review aims to explore the plausibility of new theories on the etiopathogenesis of marginal bone loss (MBL) and peri-implantitis (PI) and to discuss possible underlying pathogenic mechanisms. The former concept of osteointegration of dental implants can now be conceptualized as a foreign body response histologically characterized by a bony demarcation in combination with chronic inflammation. Different risk factors can provoke additional inflammation and, therefore, pro-inflammatory cytokine release in soft tissues and bone, leading to an overpass of the threshold of peri-implant bone defensive and regenerative capacity. Progressive bone loss observed in MBL and PI is ultimately due to a localized imbalance in the receptor activator of nuclear factor kappaB ligand (RANKL)/Receptor activator of nuclear factor κ B (RANK)/osteoprotegerin (OPG) pathway in favor of increased catabolic activity. The genetic background and the severity and duration of the risk factors could explain differences between individuals in the threshold needed to reach an imbalanced scenario. MBL and PI pathogenesis could be better explained by the "inflammation-immunological balance" theory rather than a solely "infectious disease" conception. The link between the effect of biofilm and other risk factors leading to an imbalanced foreign body response lies in osteoclast differentiation and activation pathways (over)stimulation.

IL-1 β gene (+3954 C/T, exon 5, rs1143634) and NOS2 (exon 22) polymorphisms associate with early aseptic loosening of arthroplasties

Aseptic prosthetic loosening (APL) and prosthetic joint infections (PJI) are frequent complications of hip and knee implants. Polymorphisms of cytokines and nitric oxide (NO), key inflammatory molecules in APL and PJI pathogenesis, could explain individual susceptibility to these complications. Three cytokines (IL-1-a, IL-1-β, TNF-α) and two nitric oxide synthase (NOS2, NOS3) genes polymorphisms were genotyped in 77 APL and 117 PJI patients and 145 controls with aseptic hip or knee implants that were implanted for > 16 years. Plasma cytokines and nitrate-nitrite (NOx) levels also were measured. The TT genotype and T allele of (+3954 C/T, exon 5, rs1143634) IL-1β polymorphism were more frequent in APL patients compared to controls (P = 0.03 and P = 0.02, respectively). No genotypic associations in PJI patients were observed. Plasma IL-6, TNF-α and NOx were significantly different between APL and controls (P < 0.0001). Plasma IL-1β and IL-6 were significantly higher in APL T allele carriers vs. non-carriers (P < 0.03). Knee implant (HR 2.488, 95% CI 1.307-4.739, P = 0.005), male gender (HR 2.252, 95% CI 1.121-4.525, P = 0.023), carriages of the TT genotype of the (+3954 C/T) IL-1β polymorphism (HR 3.704, 95% CI 1.274-10.753, P = 0.016) and AA genotype of the (exon 22) NOS2 polymorphism (HR 3.509, 95% CI 1.266-9.709, P = 0.016) were independently associated with a shorter implant survival by Cox regression. No genotypic associations in PJI patients were observed. Genotyping of IL-1β (+3954 C/T, exon 5, rs1143634) and NOS2 (exon 22) polymorphisms could be useful as predictors of early hip or knee APL.

LEVELS OF SMOKING AND PERI‑IMPLANT MARGINAL BONE LOSS: A SYSTEMATIC REVIEW AND META-ANALYSIS

AIM

This systematic review and meta-analysis sought to determine if there was a significantly enhanced risk of peri‑implant marginal bone loss (MBL) due to the increased number of cigarettes smoked per day.

MATERIALS AND METHODS

Six databases, including Medline, Embase, Cochrane Library, Web of Science, Scopus, and ProQuest, were searched until February, 2021. The search terms "dental implant, oral implant, smoking, smoker, non-smoker, marginal bone loss and crestal bone loss" were used in combination to seek the articles providing data for MBL related to the smoking habit. Articles were excluded if the quantity of cigarettes smoked per day was not reported. Random-effects meta-analyses were used to pool the estimates of mean difference (MD) with 95% confidence intervals (CI).

RESULTS

Eight studies were included for qualitative and 5 for quantitative synthesis. The meta-analyses revealed higher levels of MBL in patients who smoked <10 or >10 cigarettes/day than in non-smokers (<10: (MD -0.33, 95% CI -0.69-0.03 and >10: MD -0.58, 95% CI -0.96- -0.19). There was a significant risk of MBL between patients who smoked >10 and <10 cigarettes/day (MD -0.23, 95% CI -0.47-0.01).

CONCLUSION

It seems the risk of MBL is steadily increasing as daily smoking increases.

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 IL-1A and IL-1B gene polymorphisms with peri-implantitis in a Portuguese population-a pilot study

Background

Scientific evidence indicates that biological complications in dental implants tend to be concentrated in a subset of individuals, which seems to imply that the host response may play a determining role in implant success. Over the last few decades, several polymorphisms have been studied. Polymorphisms in the interleukin (IL) 1 gene cluster have been associated with periodontitis. There are some similar features in the sequence of immunopathological events in peri-implant and periodontal infections. We aimed to investigate if individuals carrying the genetic single nucleotide polymorphism (SNP) in the IL-1A (rs1800587) and IL-1B (rs1143634) genes are more susceptible to develop peri-implantitis.

Methods

A cross-sectional analytic pilot study was conducted in 20 Caucasian Portuguese subjects divided into two groups: 10 subjects with peri-implantitis and 10 subjects with peri-implant health (control group). Samples containing cells from the buccal mucosa were stored at -20 °C and later submitted to the DNA extraction process. Genetic analysis was performed using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Data were analyzed by using descriptive and inferential statistical methodologies.

Results

For the IL-1A (-889) gene polymorphism, it was observed that the mutated allele was present in a higher percentage in the peri-implantitis group compared to the control group (30% vs 15% respectively, Fisher's exact test, p = 0.45). For the IL-1B (+3954) gene polymorphism, it was also observed that the altered allele was present in a higher percentage in the disease group compared to the control group (35% vs 10% respectively, Fisher's exact test, p = 0.13). The positive genotype (at least one allele with nucleotide sequence changed in both genes) was detected in six patients, five belonging to the disease group and one to the health group.

Conclusions

Regarding IL-1 gene polymorphisms, there was no statistically significant difference between the health and disease group, however a trend should be highlighted, showing a potential link between the IL-1 genotype and peri-implantitis. More studies are needed to clarify the role of genetic polymorphisms in the development of peri-implantitis.

Diagnostic tests for titanium hypersensitivity in implant dentistry: a systematic review of the literature

PURPOSE

There are rising concerns about titanium hypersensitivity reaction regarding dental endosseous implants. This review aims to summarize and compare the validity and reliability of the available dermatological and laboratory diagnostic tests regarding titanium hypersensitivity. The following PICO design was used: In Patients with titanium dental implants (P) does epicutaneous testing (ECT) (I), compared to lymphocyte transformation test (LTT) or Memory Lymphocyte Immunostimulation Assay (MELISA) (C) detect hypersensitivity reactions (O)? A literature search was performed including all studies dealing with this topic. Studies regarding orthopedic implants were excluded.

METHODS

Three databases (MEDLINE PubMed, Cochrane Library, SciELO) were screened for suitable studies and an additional manual search was also performed. Literature regarding hypersensitivity reactions in orthopedic implants, hypersensitivity reactions regarding implants not related to dental or maxillofacial surgery, animal studies and in vitro studies were excluded. A quality assessment of all selected full-text articles was performed. Randomized, controlled trials were evaluated with the Cochrane Risk of Bias Tool I. Cohort studies were assessed according to the New Castle-Ottawa Scale and case series according to Moga et al. (Development of a quality appraisal tool for case series studies using a modified Delphi technique. 2012).

RESULTS

10 studies were included in the quantitative synthesis and available for the endpoint diagnostics of intolerance reactions to titanium dental implants: 2 clinical studies, 7 cohort studies and 1 case series. The potential for bias (internal validity) for these studies was overall rated as high.

CONCLUSIONS

The study of the available literature regarding ECT and MELISA or LTT in patients with suspected titanium hypersensitivity showed inconsistent results in terms of reliability and validity and thus, those tests should be regarded cautiously. There is strong evidence that titanium hypersensitivity in dental implants is associated with innate immunity: unspecific pro-inflammatory responses due to particle induced hyperreactivity of macrophages or toxicological responses especially towards nanoparticles rather than activation of the adaptive immune system. Therefore, tests detecting allergies do not seem expedient and inflammatory clinical signs should be regarded as leading parameters.

Association between IL-1A, IL-1B and IL-1RN Polymorphisms and Peri-Implantitis: A Systematic Review and Meta-Analysis

Recent studies report that individuals with polymorphisms in the genes that encode for interleukin (IL)-1α and IL-1β (IL-1A and IL1B, respectively) and for IL-1 receptor antagonist (IL-1RN) may be more susceptible in developing peri-implantitis. Therefore, the current systematic review evaluates what is reported about the role of genetics, more specifically of single nucleotide polymorphisms (SNP) on IL-1 and variable number of tandem repeats (VNTR) on IL-1RN, in the development of peri-implantitis. This systematic review was carried out by screening PubMed, B-on, Cochrane and Scopus databases, for articles English, Spanish, and Portuguese, with no limit regarding the publication year. Eight articles were selected for systematic review and four for meta-analytic syntheses. Our results show that although there is a lack of consensus in the literature, there seems to be an association between IL-1A, IL-1B, and IL-1RN polymorphisms with peri-implantitis. The results of the meta-analysis showed that patients who have the polymorphic allele at position +3954 of the IL-1B gene have on average almost twice the risk of developing peri-implantitis (odds ratio = 1.986, 95% confidence interval).

Role of proinflammatory mutations in peri-implantitis: systematic review and meta-analysis

Purpose

To perform a systematic review and meta-analysis on the presence of inflammatory polymorphisms in patients with peri-implantitis (PI). PI is the main complication associated to dental implant therapy. Although its main risk factors are history of periodontitis, poor plaque control and lack of regular maintenance, genetic susceptibility could also be a determinant factor for its appearance. Single nucleotide polymorphisms (SNP) are small mutations of the DNA that alter the osseointegration of implants. Inflammatory proteins participate in both destruction of the extracellular matrix and reabsorption of the alveolar bone.

Methods

A bibliographical research was made in PubMed, Scopus and Web of Science (keywords: “single nucleotide polymorphism”, “polymorphism”, “periimplantitis”, “SNP” and “implant failure”).

Results

There is a statistically significant association of peri-implant bone loss with the homozygotic model of IL-1β (− 511) (OR: 2.255; IC: 1.040–4.889).

Conclusions

Associations between inflammatory polymorphisms and PI must be taken with caution due to the heterogeneous methodological design, sample size and diagnostic criteria of the studies. Thus, more well-designed studies are needed that analyze the relationship between these and more SNP and PI.

Prevalence of peri-implantitis in a sample of HIV-positive patients

OBJECTIVES

This study aimed to assess the prevalence of peri-implantitis in human immunodeficiency virus (HIV)-positive patients and the presence of a possible correlation between the immunological profile and serological values, of peri-implantitis, and of possible differences between all-on-4 and single crown/bridge prostheses.

SUBJECTS AND METHODS

This retrospective study included 58 adult HIV-positive patients (222 implants) with either all-in-4 prostheses or single crowns/bridges on at least one dental implant loaded for more than a year who were followed for 3 year (mean follow-up). Data pertaining to the probing pocket depth (PPD), bleeding on probing, and immunological and systemic profile were collected.

RESULTS

Patients with single crown/bridge implant rehabilitation showed higher prevalence of peri-implantitis (34%) than patients with all-on-4 rehabilitation (0%) (p = 0.012). Patients with all-on-4 rehabilitation were significantly older than those with single crowns/bridges (p = 0.004). Patients with peri-implantitis had implants for a significantly longer duration than those without (p = 0.001), implying that the probability of peri-implantitis increases as the age of implant increases.

CONCLUSIONS

The prevalence of peri-implantitis was 26% in the HIV-positive patients population. No correlation was found between patients' immunological and serological factors and peri-implantitis. The most important risk factor for peri-implantitis and mucositis was implant age.

Association between common polymorphisms in IL-1 and TNFα and risk of peri-implant disease: A meta-analysis

Background

Pro-inflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor α (TNFα) play important roles in host immune response and bone metabolism during dental implant osseointegration. Whether the functional polymorphisms in IL-1α, IL-1β and TNFα were associated with peri-implant disease was unclear, and we performed the present meta-analysis for this purpose.

Methods

Eligible studies investigating IL-1α C-889T, IL-1β C+3954T and C-511T, TNFα G-308A, composite genotype of IL-1α C-889T and IL-1β C+3954T for association with peri-implant disease, including peri-implantitis (PI), marginal bone loss (MBL) and implant failure/loss (IF/IL), were searched on several literature databases prior to April 30, 2021. Odds ratio (OR) and corresponding 95% confidence interval (CI) were calculated for each polymorphism in different genetic models and for composite genotype comparing carriers to non-carriers.

Results

Twenty-seven studies (1324 cases with peri-implant disease and 1808 controls with healthy implants) were included. There was significant correlation between IL-1α C-889T and peri-implant disease in all genetic models. IL-1β C+3954T was associated with peri-implant disease risk in allelic (OR = 1.66, 95%CI 1.17–2.35, p = 0.004) and dominant model (OR = 1.74, 95%CI 1.19–2.53, p = 0.004), and in subgroups of Asians, Caucasians, non-smokers, IF/IL and PI. TT genotype of IL-1β C-511T increased the risk of peri-implant disease (OR = 1.68, 95%CI 1.15–2.43, p = 0.007) and MBL (OR = 4.33, 95%CI 1.72–10.9, p = 0.002) compared to CC+CT genotypes. We did not observed a significant association between TNFα G-308A and peri-implant diseases in overall or subgroups analysis. Carriers of positive composite genotype of IL-1α C-889T and IL-1β C+3954T had 1.95-fold (95%CI 1.35–2.80, p<0.001) risk of peri-implant disease and 1.76-fold (95%CI 1.05–2.95, p = 0.032) risk of IF/IL than non-carriers.

Conclusion

Functional polymorphisms of IL-1α (C-889T), IL-1β (C+3954T, C-511T) and composite genotype of IL-1 can be used as predictive markers for peri-implant disease, whereas TNFα G-308A polymorphism was not associated with peri-implant disease.

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).

Peri-implantitis

OBJECTIVES

This narrative review provides an evidence-based overview on peri-implantitis for the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

METHODS

A literature review was conducted addressing the following topics: 1) definition of peri-implantitis; 2) conversion from peri-implant mucositis to peri-implantitis, 3) onset and pattern of disease progression, 4) characteristics of peri-implantitis, 5) risk factors/indicators for peri-implantitis, and 6) progressive crestal bone loss in the absence of soft tissue inflammation.

CONCLUSIONS

1)Peri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. 2)The histopathologic and clinical conditions leading to the conversion from peri-implant mucositis to peri-implantitis are not completely understood. 3)The onset of peri-implantitis may occur early during follow-up and the disease progresses in a non-linear and accelerating pattern. 4a)Peri-implantitis sites exhibit clinical signs of inflammation and increased probing depths compared to baseline measurements. 4b)At the histologic level, compared to periodontitis sites, peri-implantitis sites often have larger inflammatory lesions. 4c)Surgical entry at peri-implantitis sites often reveals a circumferential pattern of bone loss. 5a)There is strong evidence that there is an increased risk of developing peri-implantitis in patients who have a history of chronic periodontitis, poor plaque control skills, and no regular maintenance care after implant therapy. Data identifying "smoking" and "diabetes" as potential risk factors/indicators for peri-implantitis are inconclusive. 5b)There is some limited evidence linking peri-implantitis to other factors such as: post-restorative presence of submucosal cement, lack of peri-implant keratinized mucosa and positioning of implants that make it difficult to perform oral hygiene and maintenance. 6)Evidence suggests that progressive crestal bone loss around implants in the absence of clinical signs of soft tissue inflammation is a rare event.

Peri-implantitis

OBJECTIVES

This narrative review provides an evidence-based overview on peri-implantitis for the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

METHODS

A literature review was conducted addressing the following topics: 1) definition of peri-implantitis; 2) conversion from peri-implant mucositis to peri-implantitis, 3) onset and pattern of disease progression, 4) characteristics of peri-implantitis, 5) risk factors/indicators for peri-implantitis, and 6) progressive crestal bone loss in the absence of soft tissue inflammation.

CONCLUSIONS

1)Peri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. 2)The histopathologic and clinical conditions leading to the conversion from peri-implant mucositis to peri-implantitis are not completely understood. 3)The onset of peri-implantitis may occur early during follow-up and the disease progresses in a non-linear and accelerating pattern. 4a)Peri-implantitis sites exhibit clinical signs of inflammation and increased probing depths compared to baseline measurements. 4b)At the histologic level, compared to periodontitis sites, peri-implantitis sites often have larger inflammatory lesions. 4c)Surgical entry at peri-implantitis sites often reveals a circumferential pattern of bone loss. 5a)There is strong evidence that there is an increased risk of developing peri-implantitis in patients who have a history of chronic periodontitis, poor plaque control skills, and no regular maintenance care after implant therapy. Data identifying "smoking" and "diabetes" as potential risk factors/indicators for peri-implantitis are inconclusive. 5b)There is some limited evidence linking peri-implantitis to other factors such as: post-restorative presence of submucosal cement, lack of peri-implant keratinized mucosa and positioning of implants that make it difficult to perform oral hygiene and maintenance. 6)Evidence suggests that progressive crestal bone loss around implants in the absence of clinical signs of soft tissue inflammation is a rare event.

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.

Current understanding of genetic polymorphisms as biomarkers for risk of biological complications in implantology

Background

In the last decade, multiple studies have been published that analyze the relationship between the risk of experiencing biological complications with implants and the presence of certain types of genetic polymorphisms. In the present report, we analyze the controversies that have arisen from this important area of investigation and synthesize the most prominent aspects of knowledge related to this possible etiopathogenic relationship.

Material and Methods

For this review, the biomedical databases PubMed-Medline, SciELO, and DOAJ were used. Different search strategies were employed, from which 298 articles initially emerged. After refinement of the search, 55 articles published between 2002 and 2018 were finally selected based on relevance.

Results

In certain population groups, there is evidence to support that about a dozen polymorphisms could in some way be related to biological complications in implantology. Indeed, the results may vary according to the ethnic origin of the population studied. Most of the published investigations are initial studies reporting small sample sizes and utilizing different study group homogenization methods. We are still at a preliminary stage of our understanding and development with regard to these types of biomarkers. The interesting results identified indicate that new investigations will be necessary to eliminate the biases observed in some studies and to homogenize the research groups. In order to clarify the controversies surrounding the current knowledge in this field, we believe that it will be necessary to employ larger study groups and search for possible synergistic effects between different polymorphisms.

Key words:Polymorphism, genetic markers, peri-implantitis, biological complication, dental implant.

Polymorphisms of Il-10 (-1082) and RANKL (-438) Genes and the Failure of Dental Implants

Background. Genetic polymorphisms in certain cytokines and chemokines have been investigated to understand why some individuals display implant flaws despite having few risk factors at the time of implant. Purpose. To investigate the association of genetic polymorphisms in interleukin- (IL-) 10 [-1082 region (A/G)] and RANKL [-438 region (A/G)] with the failure of dental implants. Materials and Methods. This study included 90 partially edentulous male and female patients who were rehabilitated with a total of 245 Straumann dental implants. An implant was considered a failure if any of the following occurred: mobility, persistent subjective complaint, recurrent peri-implant infection with suppuration, continuous radiolucency around the implant, probing depth ≥ 5 mm, and bleeding on probing. Buccal mucosal cells were collected for analysis of RANKL438 and IL-10. Results. The implant success rate in this population was 34.4%. The mutant allele (G) in RANKL had an incidence of 52.3% and mutant allele (A) in IL-10 was observed in 37.8%. No statistically significant difference was detected between the failure of the implant and the genotypes and allelic frequencies. Conclusion. No association was detected between the genetic polymorphisms of RANKL (-438) and IL-10 (-1082) and the failure of dental implants in the population studied.

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.

Retrospective long-term evaluation of dental implants in totally and partially edentulous patients. Part I: survival and marginal bone loss

PURPOSE

This retrospective longitudinal study aims to assess long-term outcomes of osseointegrated dental implants in partially and totally edentulous patients.

MATERIALS AND METHODS

Patients willing to sign the informed consent and attend a check-up were included. Implant failures were recorded, and marginal bone level and bone loss were evaluated on intraoral radiographs. Univariate and multivariate statistical analyses were conducted to determine the influence of various factors. Complications and patient satisfaction were recorded.

RESULTS

One hundred five patients who received 342 implants were included. Mean follow-up was 13.19 ± 3.70 years. 9.4% of implants were lost, and 78.1% of patients retained all implants placed. Mean marginal bone loss was 0.77 ± 1.10 mm, being greater than 3 mm in 2.5% of analyzed implants. Factors with possible influence on implant survival and marginal bone loss were smoking, osteopenia or osteoporosis, check-up frequency, implant surface, length and position, and type of prosthesis. 24.8% of patients remained free of complications. Patient satisfaction was high.

CONCLUSIONS

In our sample, which included both totally and partially edentulous patients, long-term implant survival was more than 90% with a mean marginal bone loss of 0.77 mm and an implant survival at patient level of 78%; patient satisfaction was high despite the fact that complications were frequent.

A Classification Proposal for Peri-Implant Mucositis and Peri-Implantitis: A Critical Update

Definitions of peri-implant mucositis and peri-implantitis vary in the literature, and no clear criteria have been established for the diagnosis and treatment of such disorders. This study proposes a classification for peri-implant mucositis and peri-implantitis based on the severity of the disease, using a combination of peri-implant clinical and radiological parameters to classify severity into several stages (Stage 0A and 0B = peri-implant mucositis, and Stage I to IV = periimplantitis). Following a review of the literature on the subject and justification of the proposed peri-implant disease classification, the latter aims to facilitate professional communication and data collection for research and community health studies.

Clinical significance of interleukin-1 genotype in smoking patients as a predictor of peri-implantitis: A case-control study

Background

Interleukin-1 (IL-1) is a proinflammatory cytokine that plays an important role in the pathogenesis of periodontitis, and so it might be useful to detect high-risk cases of peri-implantitis. It has been reported that IL-1 polymorphisms and smoking habit have a synergic effect, increasing the incidence of peri-implantitis. The aim of the present study was to evaluate the relationship between IL-1 gene polymorphisms and peri-implantitis in smoking patients.

Material and Methods

A case-control study was performed in 27 patients with peri-implantitis and 27 patients with healthy implants. All patients included were smokers. IL-1A-C889T, IL-1B+C3953T and IL-1RN+T2018C were identified by polymerase chain reaction (PCR) amplification in order to establish a relation between these variables and the presence of peri-implantitis. A bivariate analysis was performed and odds-ratio (OR) were calculated.

Results

The incidence of peri-implantitis was significantly higher in patients with previous history of periodontitis (p=0.024; OR=10.9). Both groups were similar regarding IL-1A-C889T, IL-1B+C3953T and IL-1RN+T2018C genotypes. No increased risk in heavy smokers with IL-1 polymorphism was found.

Conclusions

IL-1 genotypes do not seem to be good predictors of peri-implantitis in the great majority of smoking patients. Furthermore, no synergic effect was found between IL-1 genotypes and heavy smokers. Patients with a previous history of periodontitis were more prone to peri-implantitis.

Key words:Peri-implantitis, interleukin-1 genotype positive, case-control study, smoking.

Small-diameter titanium grade IV and titanium-zirconium implants in edentulous mandibles: five-year results from a double-blind, randomized controlled trial

BACKGROUND

The aim of this study was to compare the 5-year survival and success rates of 3.3 mm dental implants either made from titanium-zirconium (TiZr) alloy or from Grade IV titanium (Ti Grade IV) in mandibular implant-based removable overdentures.

METHODS

The core study had a follow-up period of 36 months and was designed as a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann Bone Level implants (diameter 3.3 mm, SLActive®), one of TiZr (test) and one of Ti Grade IV (control), in the interforaminal region. This follow-up study recruited patients from the core study and evaluated the plaque and sulcus bleeding indices, radiographic crestal bone level, as well as implant survival and success 60 months after implant placement.

RESULTS

Of the 91 patients who initially received implants, 75 completed the 36 month follow-up and 49 were available for the 60 month examination. Two patients were excluded so that a total of 47 patients with an average age of 72 ± 8 years were analysed. The characteristics and 36-month performance of the present study cohort did not differ from the non-included initial participants (p > 0.05). In the period since the 36-month follow-up examination, no implant was lost. The cumulative implant survival rate was 98.9 % for the TiZr group and 97.8 % for the Ti Grade IV group. Crestal bone level changes at 60 months were not different in the test and control group (TiZr -0.60 ± 0.69 mm and Ti Grade IV -0.61 ± 0.83 mm; p = 0.96). The cumulative implant success rate after 60 months was 95.8 and 92.6 % for TiZr and Ti Grade IV, respectively.

CONCLUSIONS

After 60 months, the positive outcomes of the 36 month results for TiZr and Ti Grade IV implants were confirmed, with no significant differences with regard to crestal bone level change, clinical parameters and survival or success rates. TiZr implants performed equally well compared to conventional Ti Grade IV 3.3 mm diameter-reduced implants for mandibular removable overdentures.

TRIAL REGISTRATION

Registered on www.clinicaltrials.gov: NCT01878331.

Key systemic and environmental risk factors for implant failure

Dental implants are an important treatment option for patients interested in replacing lost or missing teeth. Although a robust body of literature has reviewed risk factors for tooth loss, the evidence for risk factors associated with dental implants is less well defined. This article focuses on key systemic risk factors relating to dental implant failure, as well as on perimucositis and peri-implantitis.

Peri-implant diseases: a review of treatment interventions

The ideal management of peri-implant diseases focuses on infection control, detoxification of implant surfaces, regeneration of lost tissues, and plaque-control regimens via mechanical debridement (with or without raising a surgical flap). However, a variety of other therapeutic modalities also have been proposed for the management of peri-implantitis. These treatment strategies encompass use of antiseptics and/or antibiotics, laser therapy, guided bone regeneration, and photodynamic therapy. The aim of this article was to review indexed literature with reference to the various therapeutic interventions proposed for the management of peri-implant diseases.

Definition, etiology, prevention and treatment of peri-implantitis--a review

Peri-implant inflammations represent serious diseases after dental implant treatment, which affect both the surrounding hard and soft tissue. Due to prevalence rates up to 56%, peri-implantitis can lead to the loss of the implant without multilateral prevention and therapy concepts. Specific continuous check-ups with evaluation and elimination of risk factors (e.g. smoking, systemic diseases and periodontitis) are effective precautions. In addition to aspects of osseointegration, type and structure of the implant surface are of importance. For the treatment of peri-implant disease various conservative and surgical approaches are available. Mucositis and moderate forms of peri-implantitis can obviously be treated effectively using conservative methods. These include the utilization of different manual ablations, laser-supported systems as well as photodynamic therapy, which may be extended by local or systemic antibiotics. It is possible to regain osseointegration. In cases with advanced peri-implantitis surgical therapies are more effective than conservative approaches. Depending on the configuration of the defects, resective surgery can be carried out for elimination of peri-implant lesions, whereas regenerative therapies may be applicable for defect filling. The cumulative interceptive supportive therapy (CIST) protocol serves as guidance for the treatment of the peri-implantitis. The aim of this review is to provide an overview about current data and to give advices regarding diagnosis, prevention and treatment of peri-implant disease for practitioners.

Association of interleukin-1 gene variations with moderate to severe chronic periodontitis in multiple ethnicities

Background and Objective

Genetic markers associated with disease are often non-functional and generally tag one or more functional “causative” variants in linkage disequilibrium. Markers may not show tight linkage to the causative variants across multiple ethnicities due to evolutionary divergence, and therefore may not be informative across different population groups. Validated markers of disease suggest causative variants exist in the gene and, if the causative variants can be identified, it is reasonable to hypothesize that such variants will be informative across diverse populations. The aim of this study was to test that hypothesis using functional Interleukin-1 (IL-1) gene variations across multiple ethnic populations to replace the non-functional markers originally associated with chronic adult periodontitis in Caucasians.

Material and Methods

Adult chronic periodontitis cases and controls from four ethnic groups (Caucasians, African Americans, Hispanics and Asians) were recruited in the USA, Chile and China. Genotypes of IL1B gene single nucleotide polymorphisms (SNPs), including three functional SNPs (rs16944, rs1143623, rs4848306) in the promoter and one intronic SNP (rs1143633), were determined using a single base extension method or TaqMan 5′ nuclease assay. Logistic regression and other statistical analyses were used to examine the association between moderate to severe periodontitis and IL1B gene variations, including SNPs, haplotypes and composite genotypes. Genotype patterns associated with disease in the discovery study were then evaluated in independent validation studies.

Results

Significant associations were identified in the discovery study, consisting of Caucasians and African Americans, between moderate to severe adult chronic periodontitis and functional variations in the IL1B gene, including a pattern of four IL1B SNPs (OR = 1.87, p < 0.0001). The association between the disease and this IL1B composite genotype pattern was validated in two additional studies consisting of Hispanics (OR = 1.95, p = 0.04) or Asians (OR = 3.27, p = 0.01). A meta-analysis of the three populations supported the association between the IL-1 genotype pattern and moderate to severe periodontitis (OR 1.95; p < 0.001). Our analysis also demonstrated that IL1B gene variations had added value to conventional risk factors in predicting chronic periodontitis.

Conclusion

This study validated the influence of IL-1 genetic factors on the severity of chronic periodontitis in four different ethnicities.

The epidemiology of peri-implantitis

AIM

To review the literature on the prevalence and incidence of peri-implantitis.

METHODS

Out of 322 potentially relevant publications we identified 29 articles concerning 23 studies, with information on the presence of signs of peri-implantitis in populations of at least 20 cases.

RESULTS AND CONCLUSIONS

All studies provided data from convenience samples, typically from patients who were treated in a clinical center during a certain period, and most data were cross-sectional or collected retrospectively. Based on the reviewed papers one may state that the prevalence of peri-implantitis seems to be in the order of 10% implants and 20% patients during 5-10 years after implant placement but the individual reported figures are rather variable, not easily comparable and not suitable for meta-analysis. Factors that should be considered to affect prevalence figures are the disease definition, the differential diagnosis, the chosen thresholds for probing depths and bone loss, differences in treatment methods and aftercare of patients, and dissimilarities in the composition of study populations. Smoking and a history of periodontitis have been associated with a higher prevalence of peri-implantitis.

Does residual cement around implant-supported restorations cause peri-implant disease? A retrospective case analysis

OBJECTIVES

The purpose of this study was to determine the relationship between patients with a history of periodontitis and development of cement-related peri-implant disease.

MATERIALS AND METHODS

Seventy-seven patients with 129 implants for this retrospective analysis were selected from completed implant cases that were scheduled for regular maintenance or had experienced mechanical or biological complications between years 2006 and 2011 in private practice. Implants with extracoronal residual cement and implants without cement remnants were analyzed. The selected cases were further divided into two groups--implants in patients with history of periodontitis (1) and implants in periodontitis-free individuals (2). The selection of these groups was made on the basis of treatment history and orthopantomograph. As a control group, a set of 238 screw-retained implant restorations, delivered to 66 patients during the same period of time was examined. The incidence of peri-implant disease among implants in all groups was calculated.

RESULTS

Peri-implant disease was evident in 62 of 73 implants with cement remnants (85%). All implants in group 1 developed peri-implantitis--4 early and 35 delayed disease cases. In the periodontally healthy group, 20 of 31 implants were diagnosed with peri-implant mucositis, 3 implants had early peri-implantitis, and 11 implants with cement remnants did not develop biological complications. In the group of implants without cement remnants, peri-implant disease was diagnosed in 17 of 56 cases (30%). In contrast, only two occurrences of peri-implant disease were registered in the control group of screw-retained restorations (1.08%).

CONCLUSIONS

Implants with cement remnants in patients with history of periodontitis may be more likely to develop peri-implantitis, compared with patients without history of periodontal infection.

Patient-related risk factors for implant therapy. A critique of pertinent literature

BACKGROUND

Treatment planning for dental implants involves the assessment of patient-related risk factors prior to formulation of a treatment plan. The aim of this review was to assess relevant literature and provide evidence-based information on the successful surgical placement of dental implants.

METHODS

An electronic search of Medline, PubMed and the Cochrane Databases of Systematic Reviews was undertaken using a combination of MeSH terms and keywords. A handsearch was also performed and cross-referenced with articles cited in papers selected. The primary study parameter was implant failure.

RESULTS

Forty-three studies were selected based on specific inclusion criteria. Many studies contain confounding variables, numbers in subcategories are often too small for meaningful statistical analysis, and follow-up times vary and are often short-term.

CONCLUSIONS

There are many risk factors which the clinician is required to know and understand to advise patients, and consider in planning and treatment provision. Consistent evidence exists to show an increased failure rate with smokers, a history of radiotherapy and local bone quality and quantity. Weaker evidence exists to show a higher incidence of peri-implant disease in patients with a history of periodontitis-related tooth loss. Lack of evidence precludes definitive guidelines for patients with autoimmune disorders where expert opinion recommends caution. Osteoporotic patients show acceptable survival rates; however patients on oral bisphosphonates show a small incidence but high morbidity from osteonecrosis of the jaw. Emerging evidence suggests that there is a correlation between genetic traits and disruption of osseointegration.