Low prevalence of a periodontitis-associated interleukin-1 composite genotype in individuals of Chinese heritage

The effect of antimicrobial photodynamic therapy adjunct to non-surgical periodontal therapy on the treatment of periodontitis in individuals with type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

The purpose of the present systematic review and meta-analysis was to assess the impact of antimicrobial photodynamic therapy adjunct to non-surgical periodontal treatment on individuals with type 2 diabetes mellitus.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses statement was followed. Searches were carried out in six databases without restriction regarding publication year. Studies comparing periodontal clinical parameters among individuals submitted to non-surgical periodontal therapy associated with antimicrobial photodynamic therapy and a control group of individuals submitted to only non-surgical periodontal treatment were included. Study selection, data extraction, and risk of bias assessment (RoB 2.0) were performed by two review authors. Meta-analysis was performed. Mean difference (MD) and 95% confidence interval (CI) were provided.

RESULTS

Two hundred and five studies were identified and 11 studies were included. The meta-analysis demonstrated that antimicrobial photodynamic therapy adjunctive to periodontal therapy, in individuals with diabetes, resulted in a greater reduction of bleeding on probing at 6 months and in probing depth at 3 and 6 months in comparison to periodontal treatment alone (p<0.05). The included studies exhibited low risk of bias.

CONCLUSION

Antimicrobial photodynamic therapy adjunct to periodontal therapy contributes to the improvement of periodontal clinical parameter bleeding on probing and probing depth in individuals with type 2 diabetes mellitus.

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.

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).

Association between Interleukin-1β Gene Polymorphism and Chronic Periodontitis

Objectives Periodontitis is a pathological condition of the oral cavity, originating from multiple factors, including microbial, environmental and genetic factors. The vulnerability to several pathologies has been studied with the relationship to genetic polymorphisms, and one of the most prominent is the single nucleotide polymorphisms throughout the genome. The study aimed to find out the association of single nucleotide polymorphism (SNP) of interleukin-1β +3954 gene with chronic periodontitis (CP) in Pakistan

Materials and Methods This case–control study was conducted at Dow University of Health Sciences. DNA was extracted from the blood and amplified by using conventional polymerase chain reaction of respective genes followed by sequencing. Mann–Whitney test accessed the difference of clinical parameters between cases and controls, and Fisher’s exact test was applied to access the association of alleles between subjects. Data entered and analyzed using SPSS 21.

Results Significant differences were observed in clinical parameters in cases and controls ( p < 0.001). In the IL-1β +3954 gene, T alleles were significantly higher in cases as compared with controls ( p < 0.001). Genotype CC was significantly dominant in the controls and genotype CT and TT in patients (Chi-square = 19.83, p < 0.001).

Conclusion Within the study’s limits, IL-1β +3954 gene polymorphism is associated with periodontitis and is expected to be among the several causes of respective pathology in Pakistan’s population.

Oral Microbial Diversity Formed and Maintained through Decomposition Product Feedback Regulation and Delayed Responses

Oral microbial diversity plays an important role on oral health maintenance. However, there are only few kinds of substrates available for the microbial flora in oral cavity, and it still remains unclear why oral microbial diversity can be formed and sustained without obvious competitive exclusion. Based on experimental phenomena and data, a new hypothesis was proposed, namely, the decomposition product negative feedback regulation on microbial population size and microbial delay responses including reproductive, reaction, interspecific competition, and substrate decomposition delay responses induced by oral immunity. According to hypothesis and its cellular automata (CA) model, the CA simulation results sufficiently proved that the decomposition product negative feedback regulation and four microbial delay responses could significantly alleviate the interspecific competitions and inhibit the emergence of dominant species, causing the formation and sustenance of oral microbial diversity. This study could also offer effective guidance of prevention and treatment of oral cavity diseases.

Effect of compliance during periodontal maintenance therapy on c-reactive protein levels: a 6-year follow-up

AIMS

To longitudinally evaluate the effects of compliance during periodontal maintenance therapy (PMT) on C-reactive protein (CRP) levels and its relation to periodontal status.

MATERIALS AND METHODS

A subsample comprising of 30 matched pairs was taken from a previous 6-year longitudinal study under PMT. Pairs were composed of one regular (RC) and one irregular (IC) compliers, matched by age and sex. Periodontal parameters and plasma samples were collected at 3 times: T1[prior to active periodontal therapy (APT)], T2(after APT), and T3(after 6 years). CRP plasma levels were quantified using ELISA.

RESULTS

RC presented better clinical periodontal status, lower recurrence of periodontitis (sites with PD ≥4 mm and CAL ≥3 mm, together with the persistence and/or presence of BOP and/or suppuration, during any of the subsequent recall evaluations) and significant reductions in CRP levels over time [(T1: RC = 3.64 ± 2.13 and IC = 3.92 ± 2.02 mg/L) and (T3: RC = 2.12 ± 1.39 mg/L and IC = 3.71 ± 1.82 mg/L)]. Logistic regression analysis demonstrated that individuals with periodontitis recurrence presented 2.19 higher chances of presenting altered CRP levels (values ≥3 mg/L- T2 to T3) than those without periodontitis recurrence (95%CI:1.16-3.27; p = 0.017).

CONCLUSIONS

Higher CRP plasma levels were associated with higher recurrence of periodontitis and worse clinical periodontal parameters among IC when compared to RC.

Detection of association between periodontitis and polymorphisms of IL-1β + 3954 and TNF-α -863 in the Korean population after controlling for confounding risk factors

Background and Objective

Interleukin (IL)‐1 and tumor necrosis factor (TNF)‐α are inflammatory cytokines that play an important role in periodontitis, and their genetic variations have been suggested to be associated with increased risk of periodontitis. Focusing on three single nucleotide polymorphisms (SNPs) of IL‐1α + 4845, IL‐1β + 3954, and TNF‐α −863, we aimed to investigate the relationship between periodontitis risk and the polymorphisms of IL‐1 α/β and TNF‐α in Koreans.

Material and Methods

Mouthwash samples from 548 subjects (135 controls without periodontitis, 387 generalized chronic periodontitis patients, and 26 generalized aggressive periodontitis patients) were collected for isolation of genomic DNA. Genotyping of selected SNPs was performed using real‐time PCR. Univariable associations between the polymorphisms and periodontitis were assessed by chi‐squared test or Fisher's exact test. To evaluate the association after controlling for confounding effects of various risk factors, we stratified the subjects according to the presence or absence of self‐reported diseases and employed multiple logistic regression model to adjust for age, smoking status, and oral hygiene indices and behaviors.

Results

Significant association of IL‐1β + 3954 and TNF‐α −863 polymorphisms with periodontitis was observed after adjusting for the confounding risk factors, but not in univariable association analysis. The significant association between genotype CT of IL‐1β + 3954 and increased risk of advanced periodontitis was consistently detected regardless of the status of self‐reported diseases. In the polymorphism of TNF‐α −863, the genotype with minor allele (CA + AA) was significantly associated with periodontitis susceptibility, which was observed only in the subjects with self‐reported diseases.

Conclusion

The results suggest that genetic variations of IL‐1β + 3954 and TNF‐α −863 are associated with increased risk of periodontitis in Koreans. In addition, our findings underscore the importance of controlling for confounding risk factors to detect significant association between genetic factors and risk of periodontitis. A further well‐designed large‐scale study is needed to warrant our results.

Relationship between the polymorphism in the interleukin 1-β and the treatment time of patients subjected to a modified piezocision technique

Aim:

We aimed to evaluate the correlation between the polymorphism of the interleukin 1-Beta (IL1-β, +3954 C>T) and tooth movement, in a group of Colombian patients undergoing surgically accelerated orthodontic tooth movement.

Methods:

The study was nested to a controlled clinical trial. Blood samples were taken from 11 women and 29 healthy Colombian male volunteers between 18 and 40 years old, after 1 year of starting orthodontic treatment. The patients presented malocclusion class I, with grade II or III. To detect the genetic polymorphism of the nucleotide +3954 C to T in the IL-1β gene, we used a real-time PCR assay.

Results:

Eleven individuals presented the allele 2 (T) heterozygous with the allele 1 (T/C) and 19 individuals were homozygous for the allele 1 (C/C). When analyzing the presence of the SNP, no significant differences were found in any of the variables. The best treatment was reflected in Group 3 (selective upper and lower alveolar decortication and 3D collagen matrix) and Group 4 (only selective alveolar decortication in the upper arch, with 3D collagen matrix), with 27% and 35% more speed respectively than in the control group.

Conclusions:

Our analyses indicated that a reduction in the total treatment time can be mostly potentiated by using decortication and collagen matrices and not for the presence of the allele 2 in the IL-1β. Nevertheless, it is important that further studies investigate if the polymorphism could be associated with the speed of tooth movement and analyze the baseline protein levels.

Advanced glycosylated end products restrain the osteogenic differentiation of the periodontal ligament stem cell

Background/purpose

Many studies have confirmed that periodontal disease interacts with diabetes. The aim of this study was to examine whether the advanced glycosylated end products (AGEs), which are generated by diabetics, have important effects on the osteogenic differentiation of periodontal ligament stem cells (PDLSCs).

Materials and methods

In this study PDLSCs were isolated from the periodontal ligaments of extracted third molar teeth. The subjects were divided into two groups, which included the normal control group (N-PDLSCs) and the AGEs-stimulating group (A-PDLSCs). Changes of receptor of AGEs (RAGE) and cumulative ROS in PDLSCs were monitored by western blot and flow cytometry, respectively.

Results

In the study AGEs noticeably inhibited the osteogenic differentiation of PDLSCs, with significant lower calcification nodules detected in A-PDLSCs (P < 0.01). RAGE expression level and ROS accumulation in A-PDLSCs were clearly higher than those in N-PDLSCs (P < 0.01).

Conclusion

Our conclusions were that AGEs may cause the apoptosis of stem cells, which could lead to the disorder of bone differentiation function of PDLSCs.

Quality of methods and reporting in association studies of chronic periodontitis and IL1A -889 and IL1B +3953/4 SNPs: A systematic review

OBJECTIVE

The aim of this systematic review was to evaluate the quality of reporting and methodology in genetic association studies between IL1A -889 and IL1B +3954 polymorphisms and chronic periodontitis.

BACKGROUND

Evidence provided by periodontal research on genetic risk factors is of uttermost importance in clinical practice as a possible diagnostic and prognostic tool for periodontitis. Inadequate reporting of results as well as high risk of bias due to methodological inconsistency hampers the integration of evidence in terms of clinical applicability.

METHODS

This review includes case-control studies in humans published between 1997 and July 2017. Searching was conducted through MEDLINE, EMBASE, and search handing. Specific scoring systems have been developed to evaluate the quality of methods and reporting. Each article was scored according to its adequacy, and then, the total number and the percentage of items positively qualified for both methods and reporting were calculated. The quality of methods in studies scoring 0-6, 7-12, and 13-16 was, respectively, considered poor, moderate, and good. For reporting, scores of 0-9, 10-18, and 19-26 were deemed of poor, moderate, and good quality, respectively. Pearson's correlation coefficient was calculated to explore the correlation between the year of publication and the quality in terms of methods and reporting.

RESULTS

From the 531 screened studies, 52 met the inclusion criteria and were thus included in the study. The quality of methods and reporting of published genetic association papers on IL1 and chronic periodontitis is moderate. On a scale from 0 to 16, the mean score for methods of the reviewed studies was 8.19 ± 1.93. The items more frequently considered inadequate concerned the handling of confounders in statistical analysis, especially oral hygiene habits, socioeconomic status, subgingival colonization of specific periodontal pathogens, and stress. A significant positive correlation was found between the year of publication and the quality scores in terms of method (r = 0.401, P = 0.003). In terms of reporting, the mean score was 14.83 ± 3.04 on a scale from 0 to 26 and it was considered overall moderate. No statistically significant correlation was found between the year of publication and the quality of reporting (P = 0.266).

CONCLUSIONS

The association between IL1A -889 and IL1B +3954 polymorphisms and chronic periodontitis is questionable due to methodological inconsistency. Evidence arising from meta-analysis is unreliable due to high risk of bias and moderate quality in terms of reporting.

Impact of compliance during periodontal maintenance therapy on oral health-related quality of life: A 6-year follow-up

OBJECTIVE

To evaluate the effects of compliance during periodontal maintenance therapy (PMT) in the oral impact on daily performance (OIDP) measures, as well as to determine and compare the periodontal condition of acceptable and irregular compliers.

MATERIAL AND METHODS

From a 6-year prospective cohort study with 268 individuals under PMT, 232 individuals had complete periodontal clinical data and OIDP questionnaires completed between T1 (data was recorded after the first PMT appointment) and T2 (final data at the last PMT appointment), were determined to be eligible. Individuals were divided into two groups: 124 acceptable compliers (AC) and 108 irregular compliers (IC). Full-mouth periodontal examination and questionnaires were evaluated in 2 times, at T1 and T2.

RESULTS

At T2, the periodontal status of the AC group was significantly better than the IC group. The IC group also presented with higher OIDP scores (63.31 ± 19.11) compared to the AC group (57.72 ± 15.30, p = 0.005). On analyzing the OIDP dimensions independently, both groups (AC and IC) presented with high scores in the functional, psychological and social performances; however, the impacts were significantly higher in IC group.

CONCLUSION

The AC group presented with better periodontal conditions and lower OIDP, compared to the IC group. The discomfort and dissatisfaction with appearance, showed more influence on these daily impacts.

CLINICAL SIGNIFICANCE

Acceptable compliers showed lower scores of OIDP when compared to erratic ones. Thus, clinicians could take the chance to gain advantage from the positive impacts of acceptable compliance in the OHRQL for subsequent patient-centred motivation during PMT.

Immunomodulatory factors gene polymorphisms in chronic periodontitis: an overview

BACKGROUND

Chronic periodontitis (CP), defines as destruction of the supporting tissues of the teeth and resorption of the alveolar bone. It is widespread in human populations and represent an important problem for public health. CP results from inflammatory mechanisms created by the interaction between environmental and host genetic factors that confer the individual susceptibility to the disease.

AIM

The aim of the current study was to explore and summarize some functional biomarkers that are associated with CP susceptibility.

METHODS

CP is considered to be a multifactorial disease. The pathogenesis of multifactorial diseases is characterized by various biological pathways. The studies revealed that polymorphisms were associated with susceptibility to periodontal diseases. In other word, genetic variations can change the development of CP. However, there are some conflicting results, because there are different variations in frequency of some alleles in any populations. Therefore, we conducted the current review to completely understanding the special biomarkers for CP.

RESULTS

There is some evidence that SNPs in the IL-1α, IL-1β, IL1RN, IL-6, IL-10, TNF-α, TGF-β1, IFN-γ and VDR may be associated with CP susceptibility.

CONCLUSION

In conclusion, numerous studies have reported the host genetic factors associated with CP susceptibility and related traits. Therefore, it is prevail to study the multiple SNPs and their effects to find the useful diagnosis methods. The current study will investigate the relationship between polymorphisms in cytokine genes and the susceptibility to the chronic periodontitis.

Periodontal, metabolic, and cardiovascular disease: Exploring the role of inflammation and mental health

Previous evidence connects periodontal disease, a modifiable condition affecting a majority of Americans, with metabolic and cardiovascular morbidity and mortality. This review focuses on the likely mediation of these associations by immune activation and their potential interactions with mental illness. Future longitudinal, and ideally interventional studies, should focus on reciprocal interactions and cascading effects, as well as points for effective preventative and therapeutic interventions across diagnostic domains to reduce morbidity, mortality and improve quality of life.

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.

GWAS for Interleukin-1β levels in gingival crevicular fluid identifies IL37 variants in periodontal inflammation

There is no agnostic GWAS evidence for the genetic control of IL-1β expression in periodontal disease. Here we report a GWAS for "high" gingival crevicular fluid IL-1β expression among 4910 European-American adults and identify association signals in the IL37 locus. rs3811046 at this locus (p = 3.3 × 10-22) is associated with severe chronic periodontitis (OR = 1.50; 95% CI = 1.12-2.00), 10-year incident tooth loss (≥3 teeth: RR = 1.33; 95% CI = 1.09-1.62) and aggressive periodontitis (OR = 1.12; 95% CI = 1.01-1.26) in an independent sample of 4927 German/Dutch adults. The minor allele at rs3811046 is associated with increased expression of IL-1β in periodontal tissue. In RAW macrophages, PBMCs and transgenic mice, the IL37 variant increases expression of IL-1β and IL-6, inducing more severe periodontal disease, while IL-37 protein production is impaired and shows reduced cleavage by caspase-1. A second variant in the IL37 locus (rs2708943, p = 4.2 × 10-7) associates with attenuated IL37 mRNA expression. Overall, we demonstrate that IL37 variants modulate the inflammatory cascade in periodontal disease.

Comparative evaluation of the use of magnification loupes in supragingival scaling procedures

AIM

The main aim of the present investigation was to evaluate clinical and patient-centered outcomes of supragingival scaling performed with or without the use of 2.5× magnification loupes and illumination.

METHODS

A total of 30 patients, divided into three groups, were treated with 2.5× loupes and 2.5× loupes and illumination, and without any magnification device. Full-mouth plaque score percentage (FMPS%) and full-mouth bleeding score percentage (FMBS%) were registered before and after the treatment. Moreover, perceived pain and quality of the treatment were recorded using a visual analog scale. Appropriate statistical analysis was adopted to analyze between-group differences for the investigated parameters.

RESULTS

All of the patients completed the study protocol. All the groups were homogeneous at baseline. Supragingival scaling caused a significant reduction of FMPS% and FMBS% in all groups without differences among them. Moreover, no differences could be found for patient-centered outcomes. The duration of the treatment was significantly higher in the group in which loupes and illumination was used than in the control group.

CONCLUSIONS

The use of magnification loupes (with or without illumination) did not significantly improve clinical and patient-centered outcomes of supragingival scaling procedures.

Implant maintenance for the prevention of biological complications: Are you ready for the next challenge?

With increasing knowledge of wound biology and material sciences, the provision of dental implants as a treatment modality has become increasingly predictable and more commonly used to replace missing teeth. However, without appropriate follow up, peri-implant diseases could develop and affect the long-term success of implants. Currently, there is not enough focus on the prevention of peri-implant diseases, as compared to the definition of the disease, its prevalence, and treatment. In the present study, we aim to summarize various factors influencing the successful maintenance of dental implants and highlight current gaps in knowledge. Factors influencing the successful maintenance of dental implants can be divided into three categories: implant-, dentist-, and patient-related factors. Patients with dental implants are often more dentally aware, and this offers an advantage. Compared to gingiva, peri-implant mucosa responds at a different pace to the bacterial challenge. Dental practitioners should be aware of how treatment protocols affect long-term success, and be vigilant in detecting peri-implant diseases at an early stage. Compared to periodontal maintenance, less longitudinal studies on implant maintenance are available, and therefore, there is a tendency to rely heavily on information extrapolated from the periodontal literature. More studies on the significance of implant maintenance care are required.

Multidisciplinary therapy for the treatment of malocclusion in a patient with chronic periodontitis with a five-year follow-up: A case report

Multidisciplinary therapy is essential in dental practice to achieve optimized outcomes. The present case report describes the application of periodontal surgery with a five-year follow-up in a patient with malocclusion and chronic periodontitis. In the presence of periodontal inflammation, orthodontic therapy may result in further periodontal breakdown due to plaque accumulation. In order to prevent this progression, scaling and root planning with a periodontal endoscope was applied, and continuous clinical monitoring and risk assessment was performed every 3 months using a Florida Probe. This combined treatment supports the long-term maintenance of periodontal conditions, functional occlusion and harmony of the facial profile.

Association of cytokines polymorphisms with chronic peridontitis and rheumatoid arthritis in a Mexican population

OBJECTIVE

Historically, it has been shown that rheumatoid arthritis (RA) and periodontitis (PE) share pathophysiological similarities and possibly a genetic background. In order to elucidate the genetic background between both diseases, we evaluated the distributions of five SNPs genotypes and all the possible haplotypes composed in subjects with isolated RA, PE, combined diseases and healthy controls.

MATERIALS AND METHODS

The study population consisted of 280 Mexican subjects. Genomic DNA was isolated from buccal epithelial cells collected by cheek scrapings and analyzed for the determination of the following SNPs: IL-1α + 4845 (rs17561), IL-1α -889 (rs1800587), IL-1β + 3954 (rs1143634), IL-1β -511(rs16944) and TNF-α -308 (rs1800629).

RESULTS

After adjustment for age, sex and smoking status, multiple logistic regression analysis revealed a no significant association in the genotype frequencies of TNF-α -308 and IL-1α + 4845 SNPs. Otherwise a significant association was observed in IL-1β + 3954 and IL-1β -511 (p < 0.05) while IL-1α -889 was of borderline statistical significance (p = 0.054). Also, we found three negative associated haplotypes with PE: IL-1α + 4845 G/IL-1β -511 A, IL-1β + 3954 C/IL-1β -511 A and interestingly IL-1α -889 C/IL-1β -511 A also with a positive association with RA.

CONCLUSIONS

Some genotypes and haplotypes are associated with the diseases. But it seems that the genetic background of the association between RA and PE needs to be explored deeper.

Interleukin 1β (+3954; -511) Genotype Polymorphism and its Association with Severe Chronic Generalized Periodontitis in the Malaysian Population

Introduction:

Single-nucleotide polymorphisms (SNPs) in interleukin 1β (IL-1β) gene have been known to be associated with increased susceptibility to chronic periodontitis among various ethnic populations. SNPs are more commonly observed at loci + 3954 and − 511. The aim of this study was to evaluate the role of IL-1β gene polymorphism at loci +3954 and − 511, and its association with severe chronic generalized periodontitis among the ethnic Malay, Chinese, and Indians within the Malaysian population.

Materials and Methods:

Saliva samples from 120 subjects (60 cases and 60 controls) in the age group of 25–50 years were collected for isolation of genetic material using Norgen technique. Clinical attachment loss of ≥5 mm was considered as severe chronic generalized periodontitis. SNP's at loci +3954 and − 511 were identified and analyzed using Kompetitive Allele Specific Polymerase Chain Reaction Genotyping System (KASP™). Differences in the allele/genotype frequencies were assessed by Chi-square test (P < 0.05).

Results:

On the comparison between cases and controls of IL-1β genotype polymorphism (+3954 and − 511), the difference in the genotype frequencies was statistically insignificant in all the three ethnicities. The genotype frequency in both groups in all three ethnicities of the Malaysian population was similar.

Conclusion:

IL-1β genotype polymorphism at +3954 and − 511 was found to be not associated with severe chronic generalized periodontitis among the three ethnicities in Malaysia. Studies with larger sample size should be done to confirm the findings of this study.

Interaction of IL1B and IL1RN polymorphisms, smoking habit, gender, and ethnicity with aggressive and chronic periodontitis susceptibility

Background:

Although the interleukin-1 (IL-1) plays a critical role in the pathogenesis of periodontitis, associations between IL1 gene cluster polymorphisms and the disease remains unclear.

Aims:

To investigate the importance of IL1B-511C>T (rs16944), IL1B +3954C>T (rs1143634), and IL1RN intron 2 variable number tandem repeat (VNTR) (rs2234663) polymorphisms, individually or in combination, as the risk factors of periodontitis in a Southeastern Brazilian population with a high degree of miscegenation.

Subjects and Methods:

A total of 145 individuals, with aggressive (aggressive periodontitis [AgP], n = 43) and chronic (chronic periodontitis [CP], n = 52) periodontitis, and controls (n = 50) were genotyped by polymerase chain reaction (PCR) (IL1RN intron 2 VNTR) or PCR-restriction fragment length polymorphism (PCR-RFLP) (IL1B-511 C>T and IL1B + 3954C>T) techniques.

Statistical Analysis:

The independent t-test, Chi-square, and Fisher's exact tests were used. The SNPStats program was used for haplotype estimation and multiplicative interaction analyses.

Results:

The IL1B +3954T allele represented risk for CP (odds ratio [OR] = 2.84), particularly in smokers (OR = 4.43) and females (OR = 6.00). The minor alleles IL1RN*2 and *3 increased the risk of AgP (OR = 2.18), especially the IL1RN*2*2 genotype among  white Brazilians (OR = 7.80). Individuals with the combinations of the IL1B + 3954T and IL1RN*2 or *3-containing genotypes were at increased risk of developing CP (OR = 4.50). Considering the three polymorphisms (rs16944, rs1143634, and rs2234663), the haplotypes TC2 and CT1 represented risk for AgP (OR = 3.41) and CP (OR = 6.39), respectively.

Conclusions:

Our data suggest that the IL1B +3954C>T and IL1RN intron 2 VNTR polymorphisms are potential candidates for genetic biomarkers of periodontitis, particularly in specific groups of individuals.

Evaluation of anticardiolipin antibodies in tobacco users and non-tobacco users with severe chronic periodontal disease

Aims:

Many studies have proven that b2-glycoprotein-I-dependent anticardiolipin is elevated in periodontal diseases. Systemic lupus erythematosus and antiphospholipid syndrome, which are usually associated with high antiphospholipid antibodies, are more prone to adverse pregnancy outcomes and cardiovascular sequelae. Therefore, the aim of the present study is to evaluate IgG, IgM anticardiolipin antibodies in tobacco users and non-tobacco users with severe chronic periodontal disease.

Materials and Methods:

Based on the Armitage classification, 2000, 40 severe periodontitis (group D) (mean clinical attachment loss greater than 2.5 mm) male patients were selected for the study with the age range of 35–65 years and good general health from the Department of periodontics, SRM Kattankulathur Dental College, Chennai. They were classified as smokers (20 subjects) and non-smokers (20 subjects). Blood samples were collected and IgG, IgM antibodies were semi-quantitatively analyzed by enzyme-linked immunosorbent assay. The data thus collected were statistically analyzed by independent student's t-test.

Results:

Results showed that smokers with severe periodontitis exhibited marked increase in anticardiolipin IgG, IgM compared to non-smokers. They showed a positive correlation and statistical significance (P < 0.0001) between mean clinical attachment loss and IgG and IgM values.

Conclusions:

Results showed a rise in anticardiolipin antibodies in smokers with severe periodontitis, which indicates that these patients are more prone to coronary heart disease.

The mediating role of general self-efficacy in the association between perceived social support and oral health-related quality of life after initial periodontal therapy

BACKGROUND

Although initial periodontal therapy can ease some physical and psychological discomforts from periodontitis and improve patients' oral health-related quality of life (OHRQoL), it is also vital to find positive resources from psychological and social aspects to promote the overall OHRQoL. This study aims to explore the associations of perceived social support (PSS) and general self-efficacy with OHRQoL and the mediating role of general self-efficacy in PSS-OHRQoL association after initial periodontal therapy.

METHODS

A prospective case series study was conducted among consecutive outpatients with chronic periodontitis during the period of July 2014-April 2015. A total of 145 eligible patients responded to OHRQoL questionnaire and periodontal examination at baseline. About 4 to 5 weeks after initial periodontal therapy, 120 patients completed the second OHRQoL measurement and periodontal examination, along with PSS and general self-efficacy measurement. The Wilcoxon matched-pairs signed-rank test was used to determine the difference between baseline and post-treatment OHRQoL scores and periodontal parameters. Hierarchical linear regression analysis was used to explore the associations of PSS and general self-efficacy with post-treatment OHRQoL after adjusting for some demographic and periodontal variables. Asymptotic and resampling strategies were performed to explore the mediating role of general self-efficacy.

RESULTS

Initial periodontal therapy resulted in a significant improvement in the mean total score and all domains of OHRQoL and all periodontal parameters measured. In hierarchical linear regression analysis, clinical attachment loss (CAL) was significantly and positively associated with post-treatment OHRQoL score (β = 0.265, p < 0.01), while PSS (β = -0.303, p < 0.01) and general self-efficacy (β = -0.221, p < 0.01) were significantly and negatively associated with post-treatment OHRQL score, respectively. A significant mediating role of general self-efficacy (a*b = -0.139, BCa 95 % CI: -0.298, -0.011) in the association between PSS and post-treatment OHRQoL was revealed, and the proportion of the mediating role of general self-efficacy was 31.4 %.

CONCLUSIONS

Initial periodontal therapy could significantly improve all aspects of OHRQoL. PSS and general self-efficacy could be the positive resources for improving OHRQoL after initial periodontal therapy among patients with periodontitis. General self-efficacy partly mediated the association between PSS and post-treatment OHRQoL.

Decreased circulating neopterin is associated with increased arterial elasticity: a beneficial role of periodontal treatment

BACKGROUND

The aim of this study was to evaluate the effect of periodontal treatment on arterial elasticity and circulating neopterin in patients with moderate to severe periodontitis in a Chinese population.

METHODS

One hundred and eight patients with moderate to severe periodontitis were eligible to take part in the study and were randomized into two groups. The treatment group received intensive periodontal treatment, while the control group received control periodontal treatment. All parameters, including brachial-ankle pulse wave velocity (baPWV), ankle brachial index (ABI), serum neopterin (NP), high-sensitivity C-reactive protein (hs-CRP), Interleukin-6 (IL-6), were evaluated before treatment and 1 month after treatment.

RESULTS

The parameters including NP, hs-CRP, IL-6 and baPWV decreased significantly after 1 month in the treatment group (p < 0.05 for all comparisons) but not in the control group (p > 0.05). There was no significant difference in the change of ABI between the two groups (p = 0.231). A positive correlation was found between the decreased circulating NP and increased arterial elasticity in the treatment group (r = 0.947, p < 0.001).

CONCLUSIONS

This study demonstrates for the first time that the fall in circulating NP induced by periodontal treatment contributes to increased arterial elasticity in patients with moderate and severe periodontitis.

Association of susceptible genotypes to periodontal disease with the clinical outcome and tooth survival after non-surgical periodontal therapy: A systematic review and meta-analysis

Background

The real clinical utility of genetic testing is the prognostic value of genetic factors in the clinical outcome of periodontal treatment and the tooth survival. A meta-analysis was undertaken to estimate the effect of a susceptible genotype to periodontitis on the clinical outcomes of non-surgical periodontal therapy and the tooth survival.

Material and Methods

A systematic search of MEDLINE-Pubmed, Cochrane Library and Scopus was performed. Additionally, a hand search was done in three journals. No specific language restriction was applied. Two reviewers screened independently titles and abstracts or full text copies. Quality assessment of all the included studies was held.

Results

Initial screening of electronic databases resulted in 283 articles. Ten studies met the inclusion criteria, nine of them examined the clinical outcome, while the other one investigated the tooth survival in susceptible individuals after non-surgical periodontal therapy. Eight of included studies were selected for the meta-analysis. IL-1 positive genotypes increase the risk of tooth loss, while no association found between the bleeding on probing (BOP), clinical attachment loss (CAL) and plaque index (PI) with the genotype status. Probing pocket depth (PPD) reduction in the first three months and in long-term results found to have a significant association with the genotype.

Conclusions

There is no difference in the clinical measurements after non-surgical periodontal treatment, apart from PPD. More publications are needed to identify a cause-effect relationship.

Key words:Periodontal disease, periodontitis, periodontal therapy, clinical outcome, tooth loss, susceptibility, polymorphism, genotype, meta-analysis, systematic review.

Polymorphic regions in the interleukin-1 gene and susceptibility to chronic periodontitis: a genetic association study

OBJECTIVE

The objectives of this study were to determine the association between single nucleotide polymorphisms (SNPs) in IL1B (-511, +3954), IL1A (-889, +4845), and the variable number of tandem repeats (VNTRs) polymorphism in the IL-1RN gene with chronic periodontitis susceptibility and to analyze gene-gene interactions in a hospital-based sample population from South India.

SUBJECTS AND METHODS

A total of 400 individuals were recruited for this study; 200 individuals with healthy gingiva and 200 chronic periodontitis patients. Genomic DNA was isolated from peripheral blood samples and genotyping was performed for the above-mentioned single nucleotide and VNTR polymorphisms by polymerase chain reaction, DNA sequencing, and agarose gel electrophoresis.

RESULTS

A higher proportion of the variant alleles were observed in the chronic periodontitis group for all the SNPs examined. The SNP at +3954 (C>T) in the IL1B gene was found to be significantly associated with chronic periodontitis (p=0.007). VNTR genotypes (χ(2) value: 5.163, df=1, p=0.023) and alleles (χ(2) value: 6.818, df=1, p=0.009) were found to have a significant association with chronic periodontitis susceptibility.

CONCLUSION

In the study population examined, the SNP in the IL1B gene (+3954) and VNTR polymorphisms in the IL1RN gene were found to have a significant association with chronic periodontitis susceptibility.

Association between vitamin D receptor gene polymorphisms and chronic periodontitis among Libyans

BACKGROUND

Chronic periodontitis (CP) is a common oral disease characterized by inflammation in the supporting tissue of the teeth 'the periodontium', periodontal attachment loss, and alveolar bone loss. The disease has a microbial etiology; however, recent findings suggest that the genetic factors, such as vitamin D receptor (VDR) gene polymorphisms, have also been included.

AIM

Investigation of the relationship between VDR gene polymorphisms and CP among Libyans.

MATERIALS AND METHODS

In this study, we examined 196 unrelated Libyans between the ages of 25 and 65 years, including 99 patients and 97 controls. An oral examination based on Ramfjord Index was performed at different dental clinics in Tripoli and information were collected using a self-reported questionnaire. DNA was extracted from buccal swabs; the VDR ApaI, BsmI, and FokI polymorphisms were genotyped using polymerase chain reaction and were sequenced using Sanger Method.

RESULTS

A significant difference in the newly detected ApaI SNP C/T rs#731236 was found (p=0.022), whereas no significant differences were found in ApaI SNP G/T rs#7975232, BsmI SNP A/G rs#1544410, and FokI SNP A/G rs#2228570 between patients and controls (p=0.939, 0.466, 0.239), respectively.

CONCLUSION

VDR ApaI SNP C/T rs#731236 may be related to the risk of CP in the Libyan population.

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.

Cytokine gene polymorphisms associate with microbiogical agents in periodontal disease: our experience

Periodontics has evolved from a simplistic model to a more complex interplay between infection and host response. Genetic factors have been a new addition to the list of risk factors for periodontal diseases. The processes leading to destruction and regeneration of the destroyed tissues are of great interest to both researchers and clinicians. The selective susceptibility of subjects for periodontitis has remained an enigma and wide varieties of risk factors have been implicated for the manifestation and progression of periodontitis. Emerging pathway models suggest that gene-environment interactions are etiologically important in disease pathogenesis. The current practical utility of genetic knowledge in periodontitis is limited. Allelic variants at multiple gene loci probably influence periodontitis susceptibility. The pro-inflammatory cytokine interleukin-1 (IL-1) is a key modulator of host responses to microbial infection and a major modulator of extracellular matrix catabolism and bone resorption, and polymorphisms in the IL-1 gene cluster have been associated with an increased risk of developing severe adult periodontitis. The aim of this study was to test if polymorphisms of genes of IL-1α(+4845) and IL-1β(+3954) were linked with periodontitis, in a case-control study population, delimited to a specific geographic area, in association with microbiological findings. The polymorphisms observed in IL-1α(+4845) and IL-1β(+3954) single nucleotide polymorphisms (SNPs), was significantly different among the study groups (healthy controls, mild, moderate and severe periodontitis with p<0.05, d.f.=1. We found a significant correlation between the severe form of periodontitis and the presence of composite genotype (p < 0.05, d.f.=1, calculated among healthy vs. severe). Furthermore a statistically significant association between the presence of bacteria and periodontitis was detected (p<0.05, d.f.=1). In the current investigation findings were concordant with literature observations.

Correlation between the severity of periodontitis and coronary artery stenosis in a Chinese population

BACKGROUND

The aim of this study was to evaluate the relationship between the severity of periodontitis and the extent and degree of coronary artery stenosis in a Chinese population.

METHODS

Patients (n = 853) with coronary artery stenosis confirmed by coronary angiography were eligible to take part in the study. Only subjects that were ≥60 years old, had ≥50% stenosis in at least one coronary artery, and did not have diabetes or a history of smoking were included (n = 115). After periodontal examination, including bleeding index, probing depth calculus index, plaque index and periodontal attachment loss, four groups were defined based on the severity of periodontitis: no periodontitis/gingivitis (M0, n = 19); mild periodontitis (M1, n = 27); moderate periodontitis (M2, n = 31); and severe periodontitis (M3, n = 38). The extent and degree of coronary artery stenosis was obtained by calculating the Gensini score (GS).

RESULTS

The GS was significantly greater in the M3 group compared with the M0 group. Multiple linear regression analysis revealed that probing depth and plaque index were significantly correlated with the GS.

CONCLUSIONS

The extent and severity of coronary artery stenosis in Chinese patients ≥60 years old is positively correlated with the severity of periodontitis.

Intracellular adhesion molecule-1 is regulated by porphyromonas gingivalis through nucleotide binding oligomerization domain-containing proteins 1 and 2 molecules in periodontal fibroblasts

BACKGROUND

The mechanism by which Porphyromonas gingivalis regulates intracellular adhesion molecule 1 (ICAM-1) expression in human periodontal ligament cells (hPDLCs) and human gingival fibroblasts (hGFs) is unknown. The aim of this study is to investigate whether nucleotide binding oligomerization domain-containing protein (NOD) 1 and NOD2 are involved in this process and the clinical significance of ICAM-1 in periodontitis.

METHODS

hPDLCs and hGFs were treated with P. gingivalis, l-Ala-γ-d-glutamyl-mesodiaminopimelic acid (an agonist for NOD1), and muramyl dipeptide (an agonist for NOD2). Alternatively, cells transfected with small interfering RNA targeting NOD1and NOD2 were treated with P. gingivalis. ICAM-1, NOD1, and NOD2 were detected at mRNA and protein levels. In addition, clinical examinations were performed in 30 healthy controls and 40 patients with chronic periodontitis (CP) before and after treatment, and serum-soluble ICAM-1 (sICAM-1) levels in these individuals were detected by enzyme-linked immunosorbent assay.

RESULTS

This study shows that P. gingivalis caused an increase in ICAM-1, NOD1, and NOD2 expression in periodontal fibroblasts. There was a linear correlation between ICAM-1 and NOD1 and NOD2 levels. Activation of NOD1 and NOD2 by the specific agonist led to the upregulation of ICAM-1, whereas knocking down NOD1 and NOD2 caused a reduction in P. gingivalis-induced ICAM-1 production. Furthermore, sICAM-1 levels were higher in patients with CP than in healthy controls and were positively related to the clinical periodontal parameters. After periodontal treatment, sICAM-1 levels decreased significantly.

CONCLUSIONS

The present results indicate that sICAM-1 levels are correlated to the severity of periodontitis. NOD1 and NOD2 mediate P. gingivalis-induced ICAM-1 production in periodontal fibroblasts. NOD1 and NOD2 could be considered potential targets for periodontal therapy.

The Role of Interleukin-1 Genotype in the Association between Coronary Heart Disease and Periodontitis in a Syrian Population

Objective. To determine whether differences exist between periodontitis subjects with and without Coronary Heart Disease (CHD) in a Syrian population in the distribution of IL-1 alleles at positions IL-1α+4845, IL-1β+3954, IL-1β−511, and IL-1RN VNTR. Background. The role of Interleukin-1 genes in the association between periodontitis and CHD has been demonstrated in previous studies. No study has been carried out on the Syrian population to asses for such a role. Methods. 200 Syrian Arab periodontitis patients (184 males, 16 females; mean age 52.61) were divided into two groups: cases group 100 subjects with CHD (92 males, 8 females; mean age 52.06); controls group 100 subjects without CHD (92 males, 8 females; mean age 53.16). Probing depth (PD), clinical attachment loss (CAL), and alveolar bone loss (ABL) were performed for patients. Blood samples were collected for genotyping analysis of IL-1α+4845, IL-1β+3954, and IL-1β−511 using PCR-RFLP technique and IL-1RN VNTR using normal PCR. Results. An association between both (CAL and ABL) and CHD was shown after adjustment for other confounders (OR: 7.659, P = 0.001; OR: 3.645, P = 0.006, resp.). Also, an association between allele 2 of IL-1α+4845, IL-1β+3954, and IL-1β−511 and ABL was shown. Allele 2 of IL-1α+4845 and IL-1β−511 was associated with ABL among individuals with and without CHD. But after adjustment for other confounders, the association remained only between allele 2 of IL-11α+4845 and both CHD and severe ABL (OR: 0.189, P < 0.001). Conclusion. Allele 2 of IL-11α+4845 may be considered a risk indicator for having both CHD and severe ABL in the investigated Syrian population.

Evaluation of interleukin -1B (+3954) gene polymorphism in patients with chronic and aggressive periodontitis: A genetic association study

BACKGROUND

IL-1 cytokines have central roles in the pathogenesis of periodontal disease. Polymorphism in the locus +3954 (C/T) of the human IL-1B gene has been shown to affect the levels of this cytokine.

AIM

The aim of the present study was to investigate the association between the IL-1 B (+3954) gene polymorphism and the occurrence of different clinical forms of periodontitis.

MATERIALS AND METHODS

Genomic DNA was obtained from 90 individuals and amplified using the PCR with specific primers flanking the locus +3954 of IL-1B. PCR products were submitted to restriction endonuclease digestion and analyzed by gel electrophoresis, allowing for the determination of the genotypes and detection of the polymorphism.

STATISTICAL ANALYSIS

Fisher's exact test was used for comparing the frequency of genotype distributions between groups.

RESULTS

The chronic periodontitis group displayed a higher percentage of T alleles (38%) when compared to the aggressive periodontitis group (20%) and to the control group (19%).

CONCLUSION

Our study data states that polymorphism in the locus +3954 of IL-1B gene could be a risk factor for chronic periodontitis in a sample of Indian population of Karnataka state.

Interleukin-1 Two-Locus Haplotype Is Strongly Associated with Severe Chronic Periodontitis among Yemenis

Aim. To assess IL-1A C[-889]T and IL-1B C[3954]T genotypes as well as haplotypes in relation to sever chronic periodontitis (SCP) among Yemenis. Materials and Methods. 40 cases with SCP and 40 sex- and age-matched controls were included; all were nonsmokers and free of systemic diseases. Genotyping at each locus was performed using an established PCR-RFLP assay. The Haploview and SimHap software were used to assess data for Hardy-Weinberg's equilibrium (HWE) and linkage disequilibrium (LD) and to obtain subject-level haplotypes. Multiple logistic regression was used to seek for associations in dominant, additive, and recessive models. Results. Mean plaque index (MPI) showed the strongest association with SCP (OR = 16). A significant LD was observed in the cases (D' = 0.80 and r(2) = 0.47). The genotype at each locus showed significant association with SCP in the recessive model (TT versus TC + CC) even after adjustment for MPI (OR = 6.29 & 461, resp.). The C-T haplotype conferred protection against SCP in a dominant manner (OR = 0.16). On the other hand, the T-T haplotype in double dose (recessive model) showed strong association with CP (OR = 15.6). Conclusions. IL-1 two-locus haplotype is associated with SCP in Yemenis. Haplotype-based analysis may be more suited for use in genetic association studies of periodontitis.

Interleukin-1 gene polymorphisms and chronic periodontitis in adult whites: a systematic review and meta-analysis

BACKGROUND

Interleukin-1 (IL-1) gene polymorphisms have been associated with increased levels of inflammatory mediators and several inflammatory diseases. Periodontitis is a bacterially induced chronic inflammatory disease that destroys the connective tissues and bone that support the teeth, affects substantial numbers of adults, and has been implicated as a contributing factor in systemic diseases. IL-1 gene polymorphisms, most prominently IL1A (-889), IL1A (+4845), and IL1B (+3954), have been associated with chronic periodontitis (CP) in whites. Since the first report, ≥125 studies have examined IL-1 gene variation in relation to periodontal disease. These studies have produced mixed findings in diverse periodontal phenotypes and in different ethnic groups. One previous meta-analysis has been published on this topic and supported an association between IL-1 genes and periodontitis, but considerable doubt remains about the patient populations in which the association may be of clinical relevance.

METHODS

A systematic review and meta-analysis was conducted in an attempt to clarify whether IL-1 gene variants were associated with well-defined clinical phenotypes of CP in white patients. Study inclusion criteria focused on the analytic framework originally proposed for the IL-1 genetic effect in which overexpression of inflammatory mediators is hypothesized to result in more severe periodontitis in response to a bacterial challenge.

RESULTS

Twenty-seven studies were included in the qualitative analysis. Nineteen studies yielded significant associations between carriage of the minor IL-1 alleles and periodontitis. The meta-analysis, based on 13 qualifying studies, found significant effects for the two individual gene variations (IL1A odds ratio [OR] = 1.48; IL1B OR = 1.54) and for a composite genotype that combines minor alleles at each locus (OR = 1.51). Statistically significant heterogeneity was found that could not be explained, but there was no indication of publication bias.

CONCLUSION

This review and meta-analysis show that IL1A and IL1B genetic variations are significant contributors to CP in whites.

Genetic polymorphism studies in periodontitis and Fcγ receptors

Periodontitis is a complex chronic subgingival plaque-induced inflammatory disease influenced by multiple factors, including genetics, behavior and the environment. Many genetic association studies have been conducted in periodontology. One of the most extensively investigated gene families is the Fcγ receptor gene family, which plays a key role in regulating host immune responses to bacteria. Unlike other genetic polymorphisms reported in periodontology, most Fcγ receptor polymorphisms reported not only have established biological functions but are reported to associate with other autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. There are, however, few recent reviews summarizing the association of this gene family with periodontitis. This article critically reviews the current understanding of genetic polymorphism studies in periodontitis, then summarizes the research status of Fcγ receptor polymorphisms and periodontitis and also of other genes involved in the regulatory network of Fcγ receptors, with special reference to their anticipated biological roles. Moreover, some possible future research directions in the related area are discussed.

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 Interleukin-1 Allele 2 Genotype (IL-1a−889 and IL-1b+3954) on the Individual's Susceptibility to Peri-Implantitis: Case-Control Study

Individuals bearing the combination of interleukin (IL)-1 allele 2 at IL-1A−889 and IL-1B+3954 are referred to as being genotype positive and are susceptible to increased periodontal tissue destruction. The aim of this study was to assess the possible association of IL-1 allele 2 (IL-1A−889 and IL-B+3954) genotypes with the severity of peri-implantitis progression and the effect of this combination on treatment outcomes. Fifty patients with International Team for Implantology implants were studied; patients ranged in age from 35–55 years, and each patient had 1 implant. According to peri-implant tissue status, patients were divided into 2 groups: group I consisted of 25 patients with peri-implantitis, and group II comprised 25 patients with healthy peri-implant tissue. Clinical parameters were assessed at baseline and after 3 and 6 months. Epithelial cells were collected from the oral mucosa by plastic spatula and were used for IL-1 genotyping by the polymerase chain reaction technique. Group I patients were subjected to a peri-implantitis treatment and maintenance program. In all, 17 patients from group I and 5 patients from group II were genotype positive, with a statistically significant difference noted between the 2 groups. Group I genotype-positive patients presented with higher scores and measurements of clinical parameters with increased suppuration from peri-implant tissues compared with group II; differences were statistically significant (P &lt; .05). In terms of response to treatment, genotype-negative patients demonstrated better response than genotype-positive patients. The combination of IL-1 allele 2 (IL-1A−889 and IL-1B+3954) in patients with inflamed periodontal or peri-implant tissues acts as a risk factor that leads to greater tissue destruction. IL-1 gene polymorphism at IL-1A−889 and IL-1B+3954 may affect outcomes of treatment for peri-implantitis in genotype-positive individuals.