Environmental and other modifying factors of the periodontal diseases

Microbial diagnostics in periodontal diseases

Microbial analytical methods have been instrumental in elucidating the complex microbial etiology of periodontal diseases, by shaping our understanding of subgingival community dynamics. Certain pathobionts can orchestrate the establishment of dysbiotic communities that can subvert the host immune system, triggering inflammation and tissue destruction. Yet, diagnosis and management of periodontal conditions still rely on clinical and radiographic examinations, overlooking the well-established microbial etiology. This review summarizes the chronological emergence of periodontal etiological models and the co-evolution with technological advances in microbial detection. We additionally review the microbial analytical approaches currently accessible to clinicians, highlighting their value in broadening the periodontal assessment. The epidemiological importance of obtaining culture-based antimicrobial susceptibility profiles of periodontal taxa for antibiotic resistance surveillance is also underscored, together with clinically relevant analytical approaches to guide antibiotherapy choices, when necessary. Furthermore, the importance of 16S-based community and shotgun metagenomic profiling is discussed in outlining dysbiotic microbial signatures. Because dysbiosis precedes periodontal damage, biomarker identification offers early diagnostic possibilities to forestall disease relapses during maintenance. Altogether, this review highlights the underutilized potential of clinical microbiology in periodontology, spotlighting the clinical areas most conductive to its diagnostic implementation for enhancing prevention, treatment predictability, and addressing global antibiotic resistance.

Is there an association between periodontal disease and root caries? A systematic review and meta-analysis

Some periodontal diseases can be associated with cariogenic bacterial growth due to various oral health imbalances. This fact may be linked to a greater development of root caries. Thus, this systematic review analyzed the evidence on the association between periodontal disease and root caries. An electronic search was performed in five databases (Cochrane Library, LILACS, MedLine via PubMed, Scopus, and Web of Science) and two additional sources (Google Scholar and Open Grey) to partially capture the grey literature. The PECO strategy was used to identify prospective or retrospective observational studies assessing root caries in patients with periodontal disease without language or year publication restrictions. Two reviewers extracted data and evaluated the individual risk of bias in the eligible studies. Random effects meta-analyses were performed to calculate the Odds Ratio (OR). The risk of bias was assessed by the NIH tool, and the certainty of evidence was classified according to the GRADE tool. There were 1,725 studies retrieved, of which four met the eligibility criteria. All of them were evaluated for the control statements for possible confounders, bias consideration, and confounding factors because they had multivariate analysis. Adults with periodontal disease had a greater chance of presenting root caries than adults without, with OR 1.38 [CI 1.25, 1.53]. The certainty of evidence was classified as very low. Within the limits presented in this review, there was an association between periodontal disease and root caries, highlighted in the qualitative synthesis and the meta-analysis results.

Comparative effect of anthocyanin on proliferation and migration of human gingival fibroblasts in the absence or presence of nicotine

Background

Oral fibroblast malfunction can result in periodontal diseases. Nicotine can prolong the healing process as an irritant of oral tissues. Anthocyanins have been demonstrated to have potential benefits in preventing or treating smoking-related periodontal diseases. Cyanidin chloride's (CC's) potential in oral wound healing and the viability, proliferation, and migration of human gingival fibroblasts (HGFs) were examined in the presence and absence of nicotine by an in vitro study.

Methods

The effects of different nicotine concentrations (1, 2, 3, 4, and 5 mM) on the viability and proliferation of HGF cells were evaluated in the presence and absence of different CC concentrations (5, 10, 25, and 50 μM) using the quantitative MTT assay. The scratch test was performed to evaluate the migration of CC-treated cells in the presence of 2.5-mM nicotine.

Results

No cytotoxicity was observed at 1‒100 μM CC concentrations after 24, 48, and 72 hours of exposure to HGF cells. However, a concentration of 200 μM significantly reduced cell viability by about 20% at all the three-time intervals (P<0.05). Also, 3‒5-mM concentrations of nicotine significantly reduced cell viability in a dose- and time-dependent manner. Moreover, the understudied CC concentrations decreased nicotine's adverse effects on cell migration to some extent.

Conclusion

Although the understudied CC concentrations could not significantly reduce the adverse effects of understudied nicotine concentrations on the viability and proliferation of HGF cells, they were able to reduce the detrimental effects of nicotine on cell migration significantly.

Expression of Interleukin 17A and 17B in Gingival Tissue in Patients with Periodontitis

Periodontitis (PD) is a chronic inflammatory disease that is initiated by oral microorganisms. The pathogens induce the production of cytokines, such as interleukin (IL)-17, which enhances the inflammatory response and progression of the disease. The aim of this study was to examine the expression and localization in gingival tissue of IL-17A and IL-17B in patients with periodontitis. This study included 14 patients with periodontal disease and 14 healthy subjects without periodontal disease as a control group. There were no statistically significant differences in the expression of IL-17A mRNA between patients with periodontitis and control subjects. The expression of IL-17B mRNA was statistically significantly lower in patients with periodontitis in comparison with healthy subjects (p < 0.048). The expression of IL-17A correlated significantly with the approximal plaque index. The IL-17B expression in gingival tissue correlated with the clinical attachment level. This correlation reached borderline statistical significance (p = 0.06). In immunohistochemical analysis, we have shown the highest expression of IL-17 protein in inflamed connective tissue, epithelium, and granulation tissue from gingival biopsy specimens from patients with periodontitis. In biopsy specimens from healthy individuals, no IL-17 was found in the epithelium, while an expression of IL-17 was found in the connective tissue. The results of our study confirm the involvement of IL-17 in the pathogenesis of periodontitis. Our results suggest that an increase in IL-17 protein expression in the gingival tissue of patients with periodontitis occurs at the post-translational stage.

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.

Exposure to domestic abuse and the subsequent risk of developing periodontal disease

Aims

Periodontal disease and domestic abuse (DA) are significant public health problems. Previous cross-sectional evidence indicates an association between DA exposure and development of periodontal disease. There have been no large-scale cohort studies exploring this relationship in a UK-setting. Our aim was to conduct a population-based retrospective open cohort study to explore the association between DA exposure and the subsequent development of general practitioner (GP)-coded periodontal disease.

Materials and methods

We undertook a retrospective open-cohort study using the IQVIA Medical Research Database (IMRD) UK database between the 1^st January 1995 to 31^st January 2021. Women (aged 18 years and over) exposed to DA were matched by age, deprivation, and smoking status to up to 4 unexposed women, all of whom had no pre-existing record of periodontal disease. Cox regression analysis was used to calculate crude and adjusted hazard ratios (HRs) to describe the risk of developing periodontal disease in the exposed group.

Results

23429 exposed patients were matched to 69815 unexposed patients. During the study period, 78 exposed patients had developed GP-recorded periodontal disease compared to 154 in the unexposed group, translating to an IR of 94.18 per 100,000 person years (py) and 54.67 per 100,000 py respectively. Following adjustment for key covariates, this translated to an aHR of 1.74 (95% CI 1.31-2.32), which was robust during our sensitivity analysis.

Conclusions

Our results provide further evidence that DA exposure is associated with increased risk of developing periodontal disease. There is a need for swift implementation of public health policies to improve surveillance, reporting, and prevention of DA.

Pathogenic associations between oral and gastrointestinal diseases

Both periodontitis and inflammatory bowel disease (IBD) are complex chronic conditions characterized by aberrant host immune response and dysregulated microbiota. Emerging data show an association between periodontitis and IBD, including direct and indirect mechanistic links between oral and intestinal inflammation. Direct pathways include translocation of proinflammatory microbes from the oral cavity to the gut and immune priming. Indirect pathways involve systemic immune activation with possible nonspecific effects on the gut. There are limited data on the effects of periodontal disease treatment on IBD course and vice versa, but early reports suggest that treatment of periodontitis decreases systemic immune activation and that treatment of IBD is associated with periodontitis healing, underscoring the importance of recognizing and treating both conditions.

Factors affecting periodontal healing of the adjacent second molar after lower third molar surgery: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aim to evaluate the effect modifiers which may influence the periodontal healing of the adjacent second molar after lower third molar surgery.

MATERIALS AND METHODS

Prospective studies including patients with third molars requiring removal, with at least 6 months follow-up were considered. Outcomes were periodontal probing depth (PPD) reduction, final PPD, clinical attachment level (CAL) change, final CAL, alveolar bone defect (ABD) reduction, and final ABD depth. Meta-regression was performed to identify factors.

RESULTS

Fourteen studies were included in the quantitative synthesis. At 6 months, the PPD reduction was 1.06 mm (95% CI, 0.72 to 1.39 mm) and the remaining PPD was 3.81 mm (95% CI, 3.00 to 4.62 mm). Baseline PPD was strongly correlated with the remaining PPD at 6 months (p < 0.001, adjusted R² = 70.05%).

CONCLUSIONS

Lower third molar surgery results in a modest reduction in PPD, CAL, and ABD; however, periodontal defects still remain at 6 months and beyond. Baseline PPD is strongly correlated with final PPD. While age is not shown to have effect on most of the periodontal parameters, a larger baseline PPD is more likely to manifest with increasing age and third molar surgery should be done before severe periodontitis occurs to avoid persistent periodontal defects.

CLINICAL RELEVANCE

This study shows that lower third molar surgery results in modest improvement in periodontal parameters on adjacent second molars and identified factors such as baseline PPD which may affect the healing, which may guide the pre-, peri-, and post-operative management of lower third molar surgery.

İDİYOPATİK KIRMIZI LEZYON:OLGU SERİSİ

Periodontal hastalıkların tedavisinde ilk basamak, periodontal hastalıkların etiyolojisinde rol oynayan bakteri plağı ve diştaşlarının mekanik olarak uzaklaştırılması ve oral hijyenin sağlanmasıdır. Bazı oral hastalık durumlarında mekanik tedaviye ek olarak, çeşitli sebeplerle bazı ilaç ve kimyasal ajanlar kullanılabilmektedir. Kortikostreoidler; birçok hastalığın tedavisinde güçlü antiinflamatuar, antialerjik ve immünosupresif etkileri nedeniyle oral mukokütonoz hastalıklarda sıklıkla kullanılmaktadır. Kortikosteroidlerin farklı kullanım şekilleri olsa da oral mukozal hastalıklarla ilişkili ağız lezyonlarının tedavisinde sıklıkla topikal formu tercih edilmektedir. Bu olgu serisinin amacı, konvansiyonel periodontal tedaviyi takiben iyileşmeyen dişetindeki kırmızı lezyonlara topikal kortikosteroid uygulamasının etkisini değerlendirmektir

Periodontal damage after thermal inhalation injury - The impact of high temperature inhalation injury on long term periodontal health

PURPOSE

Thermal inhalation injury is a common, life-threatening problem in burned patients. Whether or not this single event of damage to the oral integrity causes long term health problems is yet to be examined.

MATERIAL AND METHODS

All consecutive burn patients between 2014 and 2017 of Marienhospital Stuttgart (MHS), Germany, with at least 10% of burned skin surface were included and compared. The Periodontal Screening Index as well as Vitamin D levels were examined. Vitamin D has been suspected to contribute to the genesis of periodontitis. Risk factors and subjective oral life quality were prompted.

RESULTS

We included a total of 32 patients, 15 of which had an inhalation injury in their medical history. Risk factors were examined via Renatus' questionnaire. While risk factors were equally distributed in both groups we saw a remarkable difference in periodontal integrity, with the Periodontal Screening Index (PSI) per sextant differing drastically (with inhalation injury: 2.40, without inhalation injury: 1.10, p < 0.001). Patients with an inhalation injury had a mean of 5.2 out of 6 possible sextants with a pathologic PSI (with the median being 6/6), while patients without an inhalation injury had a mean of 1.83 out of 6 (median: 1/6), p < 0.001. The oral health impact profile showed a difference as well, albeit without statistical significance (with inhalation injury: median = 11, without: median = 3.5, p = 0.414). A correlation between Serum Vitamin D levels and periodontal integrity could not be seen in this group.

CONCLUSION

Inhalation injury is a possible cause for periodontitis and hence impacts the quality of life of burned patients.

Association between tooth loss, chronic conditions and common risk factors - results from the 2019 brazilian health survey

BACKGROUND

The aim of this study was to evaluate the association between systemic non-communicable diseases (NCDs; including lung, kidney, mental and cardiovascular diseases, rheumatoid arthritis, cancer and spinal problems), common risk factors, and tooth loss (TL), as an endpoint of prevalent oral NCDs (periodontitis and caries).

METHODS

A total of 60,271 noninstitutionalized adults (≥30 years) were evaluated, using data from the 2019 Brazilian National Health Survey. Negative binomial regressions were performed, adjusting for sex, age, ethnicity, educational attainment, oral hygiene, risk factors for periodontitis and caries (diabetes, smoking and a cariogenic diet). The dependent variable was TL expressed as a numerical value.

RESULTS

Diabetes, current smoking and a frequent cariogenic diet were significantly associated with TL - Incidence Rate Ratio [IRR(95%CI)]: 1.11(1.08-1.14), 1.28(1.25-1.31) and 0.97(0.94-0.99), respectively. Significant associations were observed for TL and all assessed NCDs, except for kidney diseases, cancer and musculoskeletal diseases related to work, with IRR ranging from 1.06 for hypertension and asthma to 1.16 for rheumatoid arthritis. Regular consumption (4-7 days/week) of vegetables, fruits and beef; alcohol up to 8 doses/week; and physical exercise were associated with a lower IRR for TL (p<0.05). Obesity, but not overweight, was associated with increased TL [1.05(1.03-1.07)]. Smoking, hypertension, arthritis, other mental diseases and spinal problems further increased the IRR for TL in individuals with diabetes (p<0.05).

CONCLUSION

We conclude that certain chronic systemic conditions are associated with TL in Brazilian adults. This is likely due to shared risk factors; however causal associations cannot be examined in this cross-sectional dataset. This article is protected by copyright. All rights reserved.

Co-pathogens in Periodontitis and Inflammatory Bowel Disease

Localized inflammatory lesions in one area of the body may affect other distant organs through various modes of transmission thus initiating secondary inflammatory infections. Periodontal disease (PD) and inflammatory bowel disease (IBD) have been shown to coexist. Periodontitis is a multifactorial inflammatory disease, and dental plaque is considered to be the initial risk factor. Individuals with genetic susceptibility are more likely to develop periodontitis when exposed to external stimuli. IBD is affected by host genetics, immunoregulation, daily diet, and the gut microbiota, and its risk factors appear to be shared with those of PD. However, the key etiologies of both diseases remain unclear, thus hindering the exploration of possible links between IBD and PD. Recent studies and systematic reviews have focused on evidence-based statistics of the prevalence and clinical manifestations of both diseases, but discussions of the microbial etiological correlation between periodontitis and intestinal inflammation are scarce. Here, we summarize the potential common pathogenic microorganisms that may serve as bridges between the two diseases. Studies have shown that invasive microorganisms such as Porphyromonas gingivalis, Fusobacterium nucleatum, Klebsiella spp. and Campylobacter spp. play key roles in the comorbidity of PD and IBD.

Microbiome and oral squamous cell carcinoma: a possible interplay on iron metabolism and its impact on tumor microenvironment

There is increasing evidence showing positive association between changes in oral microbiome and the occurrence of oral squamous cell carcinoma (OSCC). Alcohol- and nicotine-related products can induce microbial changes but are still unknown if these changes are related to cancerous lesion sites. In an attempt to understand how these changes can influence the OSCC development and maintenance, the aim of this study was to investigate the oral microbiome linked with OSCC as well as to identify functional signatures and associate them with healthy or precancerous and cancerous sites. Our group used data of oral microbiomes available in public repositories. The analysis included data of oral microbiomes from electronic cigarette users, alcohol consumers, and precancerous and OSCC samples. An R-based pipeline was used for taxonomic and functional prediction analysis. The Streptococcus spp. genus was the main class identified in the healthy group. Haemophilus spp. predominated in precancerous lesions. OSCC samples revealed a higher relative abundance compared with the other groups, represented by an increased proportion of Fusobacterium spp., Prevotella spp., Haemophilus spp., and Campylobacter spp. Venn diagram analysis showed 52 genera exclusive of OSCC samples. Both precancerous and OSCC samples seemed to present a specific associated functional pattern. They were menaquinone-dependent protoporphyrinogen oxidase pattern enhanced in the former and both 3',5'-cyclic-nucleotide phosphodiesterase (purine metabolism) and iron(III) transport system ATP-binding protein enhanced in the latter. We conclude that although precancerous and OSCC samples present some differences on microbial profile, both microbiomes act as "iron chelators-like" potentially contributing to tumor growth.

Long-term exposure to cigarette smoke influences characteristics in human gingival fibroblasts

BACKGROUND

Periodontal disease is a chronic inflammatory disease caused by periodontopathic bacteria accumulated in the gingival sulcus and periodontal pocket. Cigarette smoking is a well-established risk factor for periodontal disease, and periodontal tissues in smokers are chronically exposed to cigarette smoke on a long-term basis.

OBJECTIVE

In this study, we investigated the effects of long-term exposure to nicotine or cigarette smoke condensate (CSC) on cellular functions of human gingival fibroblasts (HGFs).

METHODS

In vitro-maintained HGFs were divided into two groups. The HGFs of the short-term and the long-term culture groups were cultured for 4 and 25 days, respectively, in the presence or absence of nicotine, which is one of the main components of cigarette smoke, or CSC. The cellular proliferation and migration capacities of HGFs exposed to nicotine or CSC were evaluated by WST-1 and wound healing assays. The effects of exposure to nicotine or CSC on the expression of various extracellular matrix (ECM) components, inflammatory cytokines, and senescence-related genes were examined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The cellular senescence of HGFs exposed to nicotine or CSC was detected by the senescence-associated β-galactosidase (SA-β-gal) assay. To explore the senescence-associated microRNA (miRNA), we extracted miRNA from the HGFs and the expression profiles were examined by miRNA array.

RESULTS

In short-term culture, no significant changes were observed. Long-term exposure of HGFs to nicotine or CSC significantly suppressed their cellular proliferation and migration and upregulated type Ⅰ collagen, type Ⅲ collagen, interleukin (IL)-6, IL-8, p16, p21, and p53 mRNA expression, and IL-6 and IL-8 protein expression. Furthermore, long-term nicotine or CSC exposure significantly increased the percentage of SA-β-gal-positive HGFs. In addition, long-term nicotine or CSC exposure reduced miR-29b and miR-199a expression to less than 50% of that in the unstimulated HGFs.

CONCLUSION

These data suggest that long-term smoking habits may reduce wound healing ability, modulate ECM protein homeostasis, stimulate the inflammatory response, and accelerate cellular senescence in HGFs, and consequently accelerate the progression of periodontal diseases.

Current advances of epigenetics in periodontology from ENCODE project: a review and future perspectives

BACKGROUND

The Encyclopedia of DNA Elements (ENCODE) project has advanced our knowledge of the functional elements in the genome and epigenome. The aim of this article was to provide the comprehension about current research trends from ENCODE project and establish the link between epigenetics and periodontal diseases based on epigenome studies and seek the future direction.

MAIN BODY

Global epigenome research projects have emphasized the importance of epigenetic research for understanding human health and disease, and current international consortia show an improved interest in the importance of oral health with systemic health. The epigenetic studies in dental field have been mainly conducted in periodontology and have focused on DNA methylation analysis. Advances in sequencing technology have broadened the target for epigenetic studies from specific genes to genome-wide analyses.

CONCLUSIONS

In line with global research trends, further extended and advanced epigenetic studies would provide crucial information for the realization of comprehensive dental medicine and expand the scope of ongoing large-scale research projects.

IL-17F Gene rs763780 and IL-17A rs2275913 Polymorphisms in Patients with Periodontitis

Background: Periodontitis (PD) is a chronic inflammatory disease that can eventually lead to tooth loss. Genetic and environmental factors such as smoking are involved in the pathogenesis of PD. The development of PD is potentiated by various pathogens that induce an immune response leading to the production of cytokines, such as interleukin (IL)-17. The synthesis of IL-17 is influenced genetically. The polymorphisms in IL-17 gene may affect the synthesis of IL-17. The aim of this study was to examine the association between the IL-17F rs763780 and IL-17A rs2275913 polymorphisms and PD in non-smoking and smoking patients to check if these polymorphisms could be a risk factor for PD. Methods: The study enrolled 200 patients with PD (130 non-smokers and 70 smokers) and 160 control subjects (126 non-smokers and 34 smokers). Periodontitis was diagnosed on the basis of 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. All samples were genotyped using allelic discrimination assays with TaqMan^® probes on a Real-Time PCR Detection System. Results: There were no statistically significant differences in the distribution of the IL-17F rs763780 and IL-17A rs2275913 genotypes and alleles between patients with PD and control subjects, between smoking patients with PD and smoking control subjects, and between non-smoking patients with PD and non-smoking control subjects. Conclusions: The results of this study suggest a lack of statistically significant associations between IL-17F rs763780 and IL-17A rs2275913 polymorphisms and PD in Polish population.

Diagnosis of Papillon-Lefèvre syndrome: review of the literature and a case report

Papillon-Lefëvre syndrome (PLS), classified as ectodermal dysplasia, is an autosomal recessive condition related to the cathepsin C (CTSC) gene mutation. The first clinical symptoms, occurring most commonly between the ages of 1 and 4, are palmoplantar hyperkeratosis and also periodontitis resulting in the loss of most or all teeth in the same sequence in which they erupted. Most often the redness of palms and soles precede the occurrence of keratoderma. Moreover, excessive sweating, moderate mental retardation, the tendency to purulent skin and internal organs infection may occur. Lack of cathepsin seems to have a crucial role in the intensity of symptoms. In most of the patients, there can be observed impairment of phagocytosis and chemotaxis of neutrophils, granulocytes, leukocytes and cytotoxic lesion of fibroblasts and macrophages. Also, functional impairment of lymphocytes, neutrophils, and monocytes is observed. The study, using flow cytometry, showed a decreased percentage of T cells CD8+ and increased CD4:CD8 ratio.

DEFB4A Promoter Polymorphism Is Associated with Chronic Periodontitis: A Case-Control Study

Background: Human β-defensin-2 is an antimicrobial peptide with antibiotic properties secreted by the oral cavity to protect the host against microbial attack. The inter-individual differences in defensin expression profiles due to genetic variation might be partly responsible for differences in disease susceptibility. Aims: The objective of this study was to examine whether variation in the human β-defensin-2 gene (DEFB4A) is associated with chronic periodontitis (CP). Materials and Methods: This case-control study used Sanger sequencing to analyze two promoter polymorphisms of the DEFB4A gene with potential functional consequences using DNA samples collected from 200 unrelated individuals. Results: The DEFB4A rs1339258595 promoter polymorphism is associated with CP risk and clinical attachment level (CAL) but the rs3762040 polymorphism is not. Carriers of the T allele (rs1339258595) were approximately three times less likely to develop periodontitis compared with noncarriers (p = 0.0004, odds ratio = 0.35). Consistent with a protective role, the carriers of T allele had a lower CAL compared with the wild-type (G) allele. Moreover, the wild-type diplotype (GGGG) had a significantly higher risk of tooth loss compared with other diplotypes (p = 0.016). Conclusion: This study demonstrates that genetic variation in the promoter region of DEFB4A likely affects resistance to periodontal infection and might be a potential marker for CP risk and severity.

Periodontal status correlates with anti-citrullinated protein antibodies in first-degree relatives of individuals with rheumatoid arthritis

AIM

To evaluate periodontal status in first-degree relatives of patients with rheumatoid arthritis (FDR-RA) and detect correlation with the presence of anti-citrullinated protein antibodies (ACPAs).

MATERIALS AND METHODS

Rheumatologic status and periodontal status were evaluated in a nested case-control study of FDR-RA with no diagnosis of RA at enrolment. The following parameters were assessed in 34 ACPA-positive (ACPA+) and 65 ACPA-negative (ACPA-) subjects: gingival index (GI), plaque index (PI), probing depth (PD), bleeding on probing (BOP) and clinical attachment level (CAL). We compared the two groups using conditional logistic regression.

RESULTS

In ACPA+ individuals, the mean, PD, BOP, CAL and number of sites per person with PD > 4 mm and BOP were significantly higher compared to the ACPA- group. All ACPA+ subjects had periodontitis: 44.1% presenting moderate and 47.1% severe periodontitis. ACPA- subjects had mainly mild (30.8%) and moderate (27%) periodontitis, differences being significantly different for both moderate periodontitis (p = 0.001) and severe periodontitis (p < 0.001). In multivariable analyses, ACPA status (p = 0.04) and age (p = 0.002) were significantly and independently associated with periodontal conditions.

CONCLUSION

High prevalence and severity of periodontitis in FDR-RA was associated with seropositivity to ACPAs. This further strengthens the hypothesis that periodontitis may be a risk factor in the development of RA.

Targeting epigenetic mechanisms in periodontal diseases

Epigenetic factors are heritable genome modifications that potentially impact gene transcription, contributing to disease states. Epigenetic marks play an important role in chronic inflammatory conditions, as observed in periodontal diseases, by allowing microbial persistence or by permitting microbial insult to play a role in the so-called 'hit-and-run' infectious mechanism, leading to lasting pathogen interference with the host genome. Epigenetics also affects the health sciences by providing a dynamic mechanistic framework to explain the way in which environmental and behavioral factors interact with the genome to alter disease risk. In this article we review current knowledge of epigenome regulation in light of the multifactorial nature of periodontal diseases. We discuss epigenetic tagging in identified genes, and consider the potential implications of epigenetic changes on host-microbiome dynamics in chronic inflammatory states and in response to environmental stressors. The most recent advances in genomic technologies have placed us in a position to analyze interaction effects (eg, between periodontal disease and type 2 diabetes mellitus), which can be investigated through epigenome-wide association analysis. Finally, because of the individualized traits of epigenetic biomarkers, pharmacoepigenomic perspectives are also considered as potentially novel therapeutic approaches for improving periodontal disease status.

Complement Activation as a Helping Hand for Inflammophilic Pathogens and Cancer

The complement system, an evolutionarily ancient component of innate immunity, is capable of protecting hosts from invading pathogens, either directly, by lysis of target cells, or indirectly, by mobilization of host immune mechanisms. However, this potentially cytotoxic cascade must be tightly regulated, since improperly controlled complement can damage healthy cells and tissues. The practical importance of this axis is highlighted when impairment of complement regulators or bacterial mechanisms of complement evasion result in pathogenic conditions. Recognition of complement as a "double-edged sword" is widely acknowledged, but another, currently underappreciated aspect of complement function has emerged as an important player in homeostatic balance-the dual outcome of complement-mediated inflammation. In most cases, the proinflammatory properties of complement are beneficial to the host. However, certain pathogens have developed the ability to utilize local inflammation as a source of nutrients and as a way to establish a niche for further colonization. Such a strategy can be illustrated in the example of periodontitis. Interestingly, certain tumors also seem to benefit from complement activation products, which promote a proangiogenic and immunosuppressive microenvironment.

Comparison of the Clinical Biological Width with the Published Standard Histologic Mean Values

AIMS AND OBJECTIVES

Biologic width (BW) as defined by Cohen is the part of the supracrestal gingival tissues that occupy the space between the base of the gingival crevice and the alveolar crest; it includes the junctional epithelium and the connective tissue element. Interactions between dental crowns and the marginal periodontal tissues analyzed in many review papers concluded that the recognition of the BW, in terms of crown margin placement, is beneficial for periodontal health. Therefore, knowledge of the dimensions of the sum of the junctional epithelium and connective tissue attachment as well as the sulcus depth (SD) is of clinical relevance. The aim of the study is to compare the average SD and BW clinically measured around teeth with the standard application of a mean value of 0.69 mm and 2.04 mm, respectively, found by Gargiulo et al.in a histological study on cadavers.

MATERIALS AND METHODS

Forty-two healthy patients with age ranging from 20 to 50 years presented to the Multidisciplinary Department at the Lebanese University. A total of 504 tooth sites of 126 teeth were selected and measured by two periodontists. All measurements were done on teeth requiring infiltration anesthesia for surgical, restorative, or endodontic procedures on neighboring tooth/teeth, which eliminate any ethical concerns. The SD and the distance from gingival margin to bone crest at four sites per tooth; mesial, midbuccal, distal, and midlingual/palatal were measured. Clinical, BW was calculated by subtracting SD from the distance between gingival margin to bone crest.

STATISTICAL ANALYSIS

Friedman's ANOVA test, independent samples t-tests, and one-sample t-tests were applied. The IBM^® SPSS^® statistics 20.0 statistical package was used to carry out all statistical analyses.

RESULTS

The BW is statistically significantly lower than the value stated by Gargiulo et al. (2.04 mm) with a mean value of 1.13 mm, whereas the SD is statistically significantly greater than the value stated by Gargiulo et al. (0.69 mm) with a mean value of 1.96 mm.

CONCLUSION

It can be concluded that there is a need to create a patient/site-specific distance from the proposed margin of the restoration to the bone crest when restoring subgingivally fractured or carious teeth. This leads to more stable and healthy tissues when performing crown lengthening procedures. Therefore, using the term clinical, BW is more reliable and it should be used to reestablish stability and integrity of periodontal tissues around restored teeth.

In Defense of Flossing: Part II-Can We Agree It's Premature to Claim Flossing Is Ineffective to Help Prevent Periodontal Diseases?

Periodontal diseases are complex, multifactorial disorders. Effective daily plaque control promotes gingival/periodontal health. Recent meta-analyses and other reviews have found inconclusive evidence to support that tooth flossing promotes gingival/periodontal health. Ideally, the claim should have been that, "at present, we do not have high-quality evidence from well-designed randomized clinical trials to determine whether flossing lowers the risk for periodontal diseases." Rather than "not proven to be effective," the lay public may now think that flossing is "almost entirely unhelpful and/or unnecessary." How does the dental community communicate the nuances of this topic? Herein, we examine the key structural issues underlying this area of research. We assert that effective flossing between specific teeth can promote gingival/periodontal health. Furthermore, we explore the nuances for whom this may be true and untrue, why our evidence is lacking, and what can be done to clarify the effectiveness of flossing on clinical outcomes.

Periodontal diseases

Periodontal diseases comprise a wide range of inflammatory conditions that affect the supporting structures of the teeth (the gingiva, bone and periodontal ligament), which could lead to tooth loss and contribute to systemic inflammation. Chronic periodontitis predominantly affects adults, but aggressive periodontitis may occasionally occur in children. Periodontal disease initiation and propagation is through a dysbiosis of the commensal oral microbiota (dental plaque), which then interacts with the immune defences of the host, leading to inflammation and disease. This pathophysiological situation persists through bouts of activity and quiescence, until the affected tooth is extracted or the microbial biofilm is therapeutically removed and the inflammation subsides. The severity of the periodontal disease depends on environmental and host risk factors, both modifiable (for example, smoking) and non-modifiable (for example, genetic susceptibility). Prevention is achieved with daily self-performed oral hygiene and professional removal of the microbial biofilm on a quarterly or bi-annual basis. New treatment modalities that are actively explored include antimicrobial therapy, host modulation therapy, laser therapy and tissue engineering for tissue repair and regeneration.

A Study of Diabetes Associated Oral Manifestations

Aim:

The aim of this work was to determine the frequency of oral changes in diabetic patients and to study the relationship between periodontal disease and diabetes mellitus.

Materials and Methods:

The study sample consisted of 440 known diabetic patients between the age group of 20–80 years, of which 212 were males and 228 were females. One hundred and six patients were below 40 years, 138 patients between 41 and 50 years, 97 in 51–60 years, and 99 above 60 years of age. Data were statistically analyzed by Student's t-test.

Results:

Nearly 57% of the patients showed a Russell's Periodontal Index score of 2–4.9, which suggested an established periodontal disease. Risk factors for the people above the age of 40 years to develop diabetes were 76%.

Conclusion:

The frequency of oral manifestations in diabetic patients was significantly high, hence showing a relationship of gingival and periodontal diseases with diabetes mellitus.

A Fast Method for DEFB1 - 44C/G SNP Genotyping in Brazilian Patients with Periodontitis

AIM

Defensins are cationic antimicrobial peptides expressed in epithelial cells. Such peptides exhibit antibacterial, antifungal and antiviral properties, and are a component of the innate immune response. It has been suggested that they have a protective role in the oral cavity. This study evaluated the DEFB1 polymorphism in diabetic patients with or without periodontitis in comparison to healthy controls.

MATERIAL AND METHODS

We used Hairpin-Shaped Primer (HP) assay to study the distribution of the -44 C/G SNP (rs1800972) in 119 human DNAs obtained from diabetic patients and healthy control patients.

RESULTS

The results indicate that there are no differences in distribution between groups and that in diabetic periodontitis patients the homozygous mutant could be found more frequently.

CONCLUSION

Further studies are necessary in order to investigate the role of DEFB1 polymorphisms in diabetic periodontitis patients and the influence of the peptide in periodontal pathogens.

Orthodontic management of a periodontally compromised dentition

Malocclusion superimposed with severe periodontitis may present a great challenge to clinicians while providing orthodontic treatment due the episodic and site-specific nature of the disease with risk of rapid tissue breakdown. However, orthodontic treatment in such situation may contribute significantly to the overall rehabilitation both functionally and esthetically. In this article, a case report outlines a combined periodontic-orthodontic management of compromised dentition. A 37-year-old female patient with significant medical history was treated for Class II Division 1 type of malocclusion associated with spaced upper and lower anterior teeth, deep overbite, and increased overjet, superimposed with chronic generalized periodontitis and bone loss. Treatment was completed using temporary anchorage devices assisted strategically applied force and modified tandem retraction biomechanics amidst management of acute inflammatory episodes during and mucogingival complication after treatment. Affected areas healed very well after post-orthodontic periodontal treatment with minimal pocket depth, and bleeding on probing, and a healthy zone of attached gingiva at the follow up visits. The orthodontic results lead to improvement in patient’s facial profile, lip posture, and correction of protrusion which addressed her main concern. One year follow-up shows good orthodontic and periodontic stability. The report highlights the importance of identifying “at risk” individuals and continuous monitoring of disease status during treatment. Despite all precautionary measures, a flare-up during the treatment can be anticipated.

HLA Haplotypes and Genotypes Frequencies in Brazilian Chronic Periodontitis Patients

Human leukocyte antigens (HLA) have a pivotal role in immune response and may be involved in antigen recognition of periodontal pathogens. However, the associations of HLA with chronic periodontitis (CP) have not been previously studied in the Brazilian population. In an attempt to clarify the issue of genetic predisposition to CP, we examined the distribution of HLA alleles, genotypes, and haplotypes in patients from Southern Brazil. One hundred and eight CP patients and 151 healthy and unrelated controls with age-, gender-, and ethnicity-matched were HLA investigated by polymerase chain reaction with sequence specific oligonucleotides. To exclude smoking as a predisposing factor, statistical analyses were performed in the total sample and in nonsmoking individuals. The significant results showed a positive association of the A∗ 02/HLA-B∗ 40 haplotype with CP (total samples: 4.2% versus 0%, Pc = 0.03; nonsmokers: 4.3% versus 0%, Pc = 0.23) and a lower frequency of HLA-B∗ 15/HLA-DRB1∗ 11 haplotype in CP compared to controls (total samples: 0.0% versus 4.3%, Pc = 0.04; nonsmokers: 0 versus 5.1%, P = 1.0). In conclusion, the HLA-A∗ 02/B∗ 40 haplotype may contribute to the development of CP, while HLA-B∗ 15/DRB1∗ 11 haplotype might indicate resistance to disease among Brazilians.

Prevalence of periodontitis in an adult population from an urban area in North Italy: findings from a cross-sectional population-based epidemiological survey

AIM

There is a paucity of up-to-date data regarding prevalence and risk indicators of periodontitis in Italy. Therefore, the aim of this study was to evaluate the prevalence of periodontitis and its risk indicators among adults from an urban area in North Italy.

MATERIAL AND METHODS

This cross-sectional survey used a stratified two-stage probability sampling method to draw a representative sample of the adult population of the city of Turin. About 1600 individuals, 20-75 years old, were randomly selected and 736 subjects agreed to participate (47% of the sampled subjects). Clinical parameters were assessed using a full-mouth protocol. Logistic models were applied to assess associations between periodontitis and its putative risk indicators. Age was included as restricted cubic spline.

RESULTS

Based on CDC/AAP case definition, the prevalence estimates of severe and moderate periodontitis were 34.94% (95% CI: 31.23-38.74) and 40.78% (95% CI: 36.89-44.79). The probability of periodontitis increased in smokers (adjusted OR 2.06, 95% IC: 1.26-3.37, p = 0.004) and with age but leveled off in the 50+ year-old group (p < 0.001).

CONCLUSION

Periodontitis was highly prevalent in the Turin population. The present data will enable development of appropriate public health programs and allocation of resources.

Towards understanding oral health

During the last century, dental research has focused on unraveling the mechanisms behind various oral pathologies, while oral health was typically described as the mere absence of oral diseases. The term 'oral microbial homeostasis' is used to describe the capacity of the oral ecosystem to maintain microbial community stability in health. However, the oral ecosystem itself is not stable: throughout life an individual undergoes multiple physiological changes while progressing through infancy, childhood, adolescence, adulthood and old age. Recent discussions on the definition of general health have led to the proposal that health is the ability of the individual to adapt to physiological changes, a condition known as allostasis. In this paper the allostasis principle is applied to the oral ecosystem. The multidimensionality of the host factors contributing to allostasis in the oral cavity is illustrated with an example on changes occurring in puberty. The complex phenomenon of oral health and the processes that prevent the ecosystem from collapsing during allostatic changes in the entire body are far from being understood. As yet individual components (e.g. hard tissues, microbiome, saliva, host response) have been investigated, while only by consolidating these and assessing their multidimensional interactions should we be able to obtain a comprehensive understanding of the ecosystem, which in turn could serve to develop rational schemes to maintain health. Adapting such a 'system approach' comes with major practical challenges for the entire research field and will require vast resources and large-scale multidisciplinary collaborations.

Simvastatin prevents alveolar bone loss in an experimental rat model of periodontitis after ovariectomy

Background

Periodontitis is an inflammatory disease characterized by the loss of connective tissue and alveolar bone. There is an increasing evidence that periodontitis is associated with a number of chronic disease, including osteoporosis. Periodontitis and osteoporosis are both bone destructive diseases and of high prevalence in adult population. Osteoporosis could increase some inflammatory factors that also participate in the progression of periodontitis, so as to facilitate the alveolar bone resorption. Simvastatin, specific inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme reductase, is of pleiotropic effects including anti-catabolic and anabolic effect on bone metabolism. This study aimed to explore the local and systemic effect of simvastatin on maxillary in rats with both osteoporosis and periodontitis.

Methods

Thirty-six 4-month-old female Sprague Dawley rats were randomly assigned to six groups: sham group, ligature group, ovariectomized (OVX) + ligature group, local simvastatin administration to OVX + ligature rats (local simvastatin group), oral simvastatin administration to OVX + ligature rats (oral simvastatin group), local and oral simvastatin administration to OVX + ligature rats (L&O simvastatin group). One month after OVX, ligatures were placed on the maxillary first (M1) and second molars (M2) for 4 weeks on all rats except those in the sham group, followed by simvastatin treatment for 2 months. The maxillae, serum, and femurs were collected for further examination including micro-computed (micro-CT) tomography, hematoxylin and eosin (H&E) staining, tartrate-resistant acid phosphatase (TRAP) staining, enzyme-linked immunosorbent assays (ELISA), and the three-point bending test.

Results

Local simvastatin administration increased alveolar crest height and prevented local alveolar bone loss without alteration of systemic bone loss. Oral administration prevented local and systemic bone loss with no effect on alveolar crest height.

Conclusions

Our results indicate that simvastatin has the potential of promoting bone formation and reducing alveolar bone loss in maxillary following ovariectomy (OVX) and ligature placement in rats.

Pathogenicity of the highly leukotoxic JP2 clone of Aggregatibacter actinomycetemcomitans and its geographic dissemination and role in aggressive periodontitis

For decades, Aggregatibacter actinomycetemcomitans has been associated with aggressive forms of periodontitis in adolescents. In the middle of the 1990s, a specific JP2 clone of A. actinomycetemcomitans, belonging to the cluster of serotype b strains of A. actinomycetemcomitans and having a number of other characteristics, was found to be strongly associated with aggressive forms of periodontitis, particularly in North Africa. Although several longitudinal studies still point to the bacterial species, A. actinomycetemcomitans as a risk factor of aggressive periodontitis, it is now also widely accepted that the highly leukotoxic JP2 clone of A. actinomycetemcomitans is implicated in rapidly progressing forms of aggressive periodontitis. The JP2 clone strains are highly prevalent in human populations living in Northern and Western parts of Africa. These strains are also prevalent in geographically widespread populations that have originated from the Northwest Africa. Only sporadic signs of a dissemination of the JP2 clone strains to non-African populations have been found despite Africans living geographically widespread for hundreds of years. It remains an unanswered question if a particular host tropism exists as a possible explanation for the frequent colonization of the Northwest African population with the JP2 clone. Two exotoxins of A. actinomycetemcomitans are known, leukotoxin (LtxA) and cytolethal distending toxin (Cdt). LtxA is able to kill human immune cells, and Cdt can block cell cycle progression in eukaryotic cells and thus induce cell cycle arrest. Whereas the leukotoxin production is enhanced in JP2 clone strains thus increasing the virulence potential of A. actinomycetemcomitans, it has not been possible so far to demonstrate such a role for Cdt. Lines of evidence have led to the understanding of the highly leukotoxic JP2 clone of A. actinomycetemcomitans as an aetiological factor of aggressive periodontitis. Patients, who are colonized with the JP2 clone, are likely to share this clone with several family members because the clone is transmitted through close contacts. This is a challenge to the clinicians. The patients need intense monitoring of their periodontal status as the risk for developing severely progressing periodontal lesions are relatively high. Furthermore, timely periodontal treatment, in some cases including periodontal surgery supplemented by the use of antibiotics, is warranted. Preferably, periodontal attachment loss should be prevented by early detection of the JP2 clone of A. actinomycetemcomitans by microbial diagnostic testing and/or by preventive means.

Analysis of interleukin-8 gene variants reveals their relative importance as genetic susceptibility factors for chronic periodontitis in the Han population

Interleukin (IL)-8, an important chemokine that regulates the inflammatory response, plays an important role in periodontitis. Previous studies indicate that certain IL-8 gene polymorphisms are associated with periodontitis susceptibility in some populations. However, the literature is somewhat contradictory, and not all IL-8 polymorphisms have been examined, particularly in Han Chinese individuals. The aim of this study was to investigate the association of every IL-8 SNP with chronic periodontitis in Han Chinese individuals. We analyzed 23 SNPs with minor allele frequency (MAF)≥0.01, which were selected from 219 SNPs in the NCBI dbSNP and preliminary HapMap data analyses from a cohort of 400 cases and 750 controls from genetically independent Han Chinese individuals. Single SNP, haplotype and gender-specific associations were performed. We found that rs4073 and rs2227307 were significantly associated with chronic periodontitis. Further haplotype analysis indicated that a haplotype block (rs4073-rs2227307-rs2227306) that spans the promoter and exon1 of IL-8 was highly associated with chronic periodontitis. Additionally, the ATC haplotype in this block was increased 1.5-fold in these cases. However, when analyzing the samples by gender, no significant gender-specific associations in IL-8 were observed, similar to the results of haplotype association analyses in female and male subgroups. Our results provide further evidence that IL-8 is associated with chronic periodontitis in Han Chinese individuals. Furthermore, our results confirm previous reports suggesting the intriguing possibilities that IL-8 plays a role in the pathogenesis of chronic periodontitis and that this gene may be involved in the etiology of this condition.

Isolation and identification of Porphyromonas spp. and other putative pathogens from cats with periodontal disease

The purpose of this study was to evaluate the subgingival microbiota and determine the most prevalent periodontal pathogens implicated in feline periodontal disease and to correlate these findings with the clinical periodontal status. Subgingival microbiological samples were taken under sedation from 50 cats with clinical signs of periodontal disease. Pooled paper point samples from 4 selected subgingival sites were cultured on blood agar and on Dentaid-1 medium. Suspected pathogens were identified, subcultured, and preserved. The association between the microbiological findings and the clinical status was studied using correlation coefficients (CC). In addition, cats were stratified in subgroups according to presence of putative pathogens, and comparisons were carried out using unpaired t-test. Three bacterial species were frequently detected including Porphyromonas gulae (86%), Porphyromonas circumdentaria (70%) and Fusobacterium nucleatum (90%). The mean proportion of total flora was high for P. gulae (32.54%), moderate for P. circundentaria (8.82%), and low for F. nucleatum (3.96%). Among the clinical variables, tooth mobility was correlated (CC > 0.50, p < 0.001) with recession, pocket depth, attachment level, gingival index, and calculus index (CC = 0.29, p = 0.04) as well as with total bacterial counts (CC = 0.38, p = 0.006). Cats with more than 10% of P. gulae showed significantly more mobility (p = 0.014) and recession (p = 0.038), and a tendency for deeper probing pocket depths (p = 0.084) and attachment loss (p = 0.087). The results from this cross-sectional study confirmed that P. gulae is the most relevant pathogen in periodontal disease in cats.

Inflammatory bone loss in experimental periodontitis induced by Aggregatibacter actinomycetemcomitans in interleukin-1 receptor antagonist knockout mice

The interleukin-1 receptor antagonist (IL-1Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is not clear whether IL-1Ra plays a protective role in periodontal disease. This study was undertaken to compare experimental periodontitis induced by Aggregatibacter actinomycetemcomitans in IL-1Ra knockout (KO) mice and wild-type (WT) mice. Computed tomography (CT) analysis and hematoxylin-and-eosin (H&E) and tartrate-resistant acid phosphatase (TRAP) staining were performed. In addition, osteoblasts were isolated; the mRNA expression of relevant genes was assessed by real-time quantitative PCR (qPCR); and calcification was detected by Alizarin Red staining. Infected IL-1Ra KO mice exhibited elevated (P, <0.05) levels of antibody against A. actinomycetemcomitans, bone loss in furcation areas, and alveolar fenestrations. Moreover, protein for tumor necrosis factor alpha (TNF-α) and IL-6, mRNA for macrophage colony-stimulating factor (M-CSF), and receptor activator of NF-κB ligand (RANKL) in IL-1Ra KO mouse osteoblasts stimulated with A. actinomycetemcomitans were increased (P, <0.05) compared to in WT mice. Alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN)/bone gla protein (BGP), and runt-related gene 2 (Runx2) mRNA levels were decreased (P, <0.05). IL-1α mRNA expression was increased, and calcification was not observed, in IL-1 Ra KO mouse osteoblasts. In brief, IL-1Ra deficiency promoted the expression of inflammatory cytokines beyond IL-1 and altered the expression of genes involved in bone resorption in A. actinomycetemcomitans-infected osteoblasts. Alterations consistent with rapid bone loss in infected IL-Ra KO mice were also observed for genes expressed in bone formation and calcification. In short, these data suggest that IL-1Ra may serve as a potential therapeutic drug for periodontal disease.

Oral health and menopause: a comprehensive review on current knowledge and associated dental management

The menopause is physiological changes in women that give rise to adaptive changes at both systemic and oral level. As we all begin to reach an older age, dental health and hygiene becomes a major concern. The dentist is often the first person to appreciate numerous changes that are experienced throughout the body during menopause. The teeth and gums are extremely susceptible to any hormonal changes that take place just before menopause and readily decrease body's ability to fight off minor infections or maintain a healthy balance of useful and harmful bacteria within the oral environment. This review aimed to develop better understanding for major oro-dental complications observed in women during menopause, and schematic approach towards the different dental management protocols used during these periods. Various internets based popular search engines were used to explore related data from literature, which includes PubMed, PubMed Central, Cochrane, Google, Medknow, Ebsco, Science Direct, and IndMed. Upon compilation of relevant data, it was observed that periodontal health is most severely affected (up to 60%) followed by dry mouth (25%) and burning mouth (glossodynia; 15%) which, in turn, may increase the occurrence of oral mucosal and dental diseases, such as candidiasis. Though, the usage of hormone replacement therapy is effective but it does not necessarily prevent or help women with oral symptoms. Therefore, well controlled long-term randomized studies are needed to establish more authentic clinical guidelines for successful management of such conditions.

Effect of the menstrual cycle on inflammatory cytokines in the periodontium

BACKGROUND AND OBJECTIVE

The effects of different levels of steroid hormones, as experienced during puberty, pregnancy and menopause, on the periodontium have been demonstrated, but changes in sex hormone levels during the menstrual cycle, and the influence of these changes on the periodontium, remain unresolved. The aim of this study was to investigate the effect of the menstrual cycle on the levels of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in gingival crevicular fluid and on periodontal clinical parameters, including the gingival bleeding index (GBI) and the modified gingival index (MGI), in periodontally healthy women.

MATERIAL AND METHODS

Twenty-seven periodontally healthy women with a regular menstrual cycle were included in the study. Clinical parameters, including the GBI, the MGI and the simplified oral health index, were recorded during menstruation, ovulation and premenstruation phases (e.g. on days 1-2, 12-14 and 22-24, respectively) of the menstrual cycle. Gingival crevicular fluid and unstimulated saliva were collected, at each study phase, for assessment of IL-1β, TNF-α, estrogen and progesterone.

RESULTS

Both the GBI and the MGI increased significantly during the menstrual cycle, and were significantly higher during ovulation than during menstruation or premenstruation (p < 0.001). No significant change in the simplified oral health index was observed during the menstrual cycle ( p = 0.18). The levels of IL-1β and TNF-α increased during the different phases of the menstrual cycle, but only the change in the TNF-α concentration was significant ( p < 0.05).

CONCLUSION

This study indicated that changes occurring during the menstrual cycle influence the periodontium and induce inflammatory conditions.

Preferences of UK-Based Dentists When Undertaking Root Coverage and Regenerative Procedures: A Pilot Questionnaire Study

Objectives. The purpose of the present study was to evaluate the awareness and preferences of registered United Kingdom (UK) dentists specialising or with an interest in periodontics in root coverage and regenerative procedures. Methods. A cross-sectional postal survey of 366 dentists was conducted. The questionnaire was divided in two sections and most of the questions were giving the option of multiple answers. Frequencies and associations between the demographic profiles of the participants with their answers were evaluated. Results. 63% of dentists with an interest in periodontics and 32% of specialists returned the questionnaire. Guided tissue regeneration procedures and the use of enamel matrix derivatives were recommended for the reconstruction of bony defects and both subepithelial connective tissue graft and coronally advanced flap with or without enamel matrix derivatives were the most popular choices for root coverage. Smoking was considered a contraindication by most of the participants and conflicting responses were given regarding the use of antibiotics as part of the care following regenerative procedures. Conclusions. The participants incorporated both traditional and “novel” techniques and products in reconstructive procedures and appeared to be up to date with the evidence from the dental literature. However, it was evident that there was confusion regarding the role of antibiotics in regenerative procedures.

The role of TLR4 896 A>G and 1196 C>T in susceptibility to infections: a review and meta-analysis of genetic association studies

Background

Toll-like receptor 4 plays a role in pathogen recognition, and common polymorphisms may alter host susceptibility to infectious diseases.

Purpose

To review the association of two common polymorphisms (TLR4 896A>G and TLR4 1196C>T) with infectious diseases.

Data Sources

We searched PubMed and EMBASE up to March 2013 for pertinent literature in English, and complemented search with references lists of eligible studies.

Study Selection

We included all studies that: reported an infectious outcome; had a case-control design and reported the TLR4 896A>G and/or TLR4 1196C>T genotype frequencies; 59 studies fulfilled these criteria and were analyzed.

Data Extraction

Two authors independently extracted study data.

Data Synthesis

The generalized odds ratio metric (OR_G) was used to quantify the impact of TLR4 variants on disease susceptibility. A meta-analysis was undertaken for outcomes reported in >1 study. Eleven of 37 distinct outcomes were significant. TLR4 896 A>G increased risk for all parasitic infections (OR_G 1.59; 95%CI 1.05-2.42), malaria (1.31; 95%CI 1.04-1.66), brucellosis (2.66; 95%CI 1.66-4.27), cutaneous leishmaniasis (7.22; 95%CI 1.91-27.29), neurocysticercosis (4.39; 95%CI 2.53-7.61), Streptococcus pyogenes tonsillar disease (2.93; 95%CI 1.24-6.93) , typhoid fever (2.51; 95%CI 1.18-5.34) and adult urinary tract infections (1.98; 95%CI 1.04-3.98), but was protective for leprosy (0.36; 95%CI 0.22-0.60). TLR4 1196 C>T effects were similar to TLR4 896 A>G for brucellosis, cutaneous leishmaniasis, leprosy, typhoid fever and S. pyogenes tonsillar disease, and was protective for bacterial vaginosis in pregnancy (0.55; 95%CI 0.31-0.98) and Haemophilus influenzae tonsillar disease (0.42; 95%CI 0.17-1.00). The majority of significant associations were among predominantly Asian populations and significant associations were rare among European populations.

Conclusions

Depending on the type of infection and population, TLR4 polymorphisms are associated with increased, decreased or no difference in infectious disease. This may be due to differential functional expression of TLR4, the co-segregation of TLR4 variants or a favorable inflammatory response.

The relationship between gastroesophageal reflux disease and chronic periodontitis

Background/Aims

The most common cause of chronic periodontitis is poor oral hygiene. Gastroesophageal reflux disease (GERD) enhances the proximal migration of gastric contents and may cause poor oral hygiene. We hypothesized that GERD may increase thse risk of chronic periodontitis and investigated this potential relationship.

Methods

A retrospective cross-sectional study was conducted in outpatients between January 1, 2010, and April 30, 2012. GERD was defined as being present based on at least two of the following criteria: etiologic agent(s), identifiable signs and symptoms, and consistent anatomic alterations. A total of 280 patients with chronic periodontitis and 280 controls were analyzed. Information regarding patient demographics and other potential confounding factors for chronic periodontitis were collected through individual medical records.

Results

GERD was revealed to be independently associated with an increased incidence of chronic periodontitis (odds ratio [OR], 2.883; 95% confidence interval [CI], 1.775 to 4.682). The other three variables of dental caries (OR, 1.531; 95% CI, 1.042 to 2.249), tobacco use (OR, 2.335; 95% CI, 1.461 to 3.730), and history of medication (calcium channel blocker, cyclosporine, or phenytoin) (OR, 2.114; 95% CI, 1.160 to 3.854) were also determined to be independent risk factors.

Conclusions

The present study supported our hypothesis that GERD can be a risk factor for chronic periodontitis.

Effect of Nadir CD4+ T cell count on clinical measures of periodontal disease in HIV+ adults before and during immune reconstitution on HAART

Background

The contribution of HIV-infection to periodontal disease (PD) is poorly understood.  We proposed that immunological markers would be associated with improved clinical measures of PD.

Methods

We performed a longitudinal cohort study of HIV-infected adults who had started highly active antiretroviral therapy (HAART) <2 years. PD was characterized clinically as the percent of teeth with ≥1 site with periodontal probing depth (PPD) ≥5.0mm, recession (REC) >0mm, clinical attachment level (CAL) ≥4.0mm, and bleeding on probing (BOP) at ≥4 sites/tooth and microbiologically as specific periodontopathogen concentration. Linear mixed-effects models were used to assess the associations between immune function and PD.

Results

Forty (40) subjects with median 2.7 months on HAART and median nadir CD4+ T-cell count of 212 cells/μl completed a median 3 visits. Over 24 months, CD4+ T-cell count increased by a mean 173 cells/µl (p<0.001) and HIV RNA decreased by 0.5 log₁₀ copies/ml (p<0.001); concurrently, PPD, CAL and BOP decreased by a mean 11.7%, 12.1%, and 14.7% respectively (all p<0.001). Lower nadir CD4+ T-cell count was associated with worse baseline REC (-6.72%; p=0.04) and CAL (9.06%; p<0.001). Further, lower nadir CD4+ T-cell count was associated with a greater relative longitudinal improvement in PPD in subjects with higher baseline levels of Porphyromonas gingivalis (p=0.027), and BOP in subjects with higher baseline levels of Porphyromonas gingivalis or Treponema denticola (p=0.001 and p=0.006 respectively). Longitudinal changes from baseline in CD4+ T-cell count and level of HIV RNA were not independently associated with longitudinal changes in any clinical markers of PD.

Conclusion

Degree of immunosuppression was associated with baseline gingival recession. After HAART initiation, measures of active PD improved most in those with lower nadir CD4+ T-cell counts and higher baseline levels of specific periodontopathogens. Nadir CD4+ T-cell count differentially influences periodontal disease both before and after HAART in HIV-infected adults.

Microflora and periodontal disease

Background:

Periodontitis is a disease that affects and destroys the tissues that support teeth. Tissue damage results from a prolonged inflammatory response to an ecological shift in the composition of subgingival biofilms. Three bacterial species that constitute the red complex group, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, are considered the main pathogens involved in periodontitis.

Materials and Methods:

In the present study, a real-time polymerase chain reaction bases assay was designed to detect and quantify red complex species, then used to investigate 307 periodontal pocket samples from 127 periodontitis patients and 180 controls.

Results:

Significant higher prevalence of red complex species and increased amount of P. gingivalis and T. denticola were detected in periodontal pocket of periodontitis patients.

Conclusions:

Results demonstrated that the test is a valuable tool to improve diagnosis of periodontal disease.

Lipopolysaccharide of Aggregatibacter actinomycetemcomitans up-regulates inflammatory cytokines, prostaglandin E2 synthesis and osteoclast formation in interleukin-1 receptor antagonist-deficient mice

BACKGROUND AND OBJECTIVE

The interleukin (IL)-1 receptor antagonist (Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is unclear whether the IL-1Ra plays a protective role in periodontal disease. The purpose of this study was to compare IL-1Ra knockout (KO) and wild-type (WT) mice in regard to proinflammatory cytokine production, osteoclast formation and bone resorption in response to periodontal bacterial lipopolysaccharide (LPS).

MATERIAL AND METHODS

Peritoneal macrophages (Mφs) were obtained from 13-wk-old IL-1Ra KO and WT mice. Peritoneal Mφs were cultured with or without 10 μg/mL of Aggregatibacter actinomycetemcomitans LPS for 24 h. The levels of IL-1alpha (IL-1α), IL-1beta (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6 were measured in periotoneal Mφs supernatant fluid (PM-SF) using an ELISA. Bone marrow cells were obtained from the mice and stimulated with PM-SF for 9 d, then stained with TRAP. The frequency of TRAP-positive multinucleated giant cell formation was calculated based on a fusion index. PM-SF-stimulated calvarial bone resorption was analyzed using micro-computed tomography, and calvarial histological analysis was performed using hematoxylin and eosin and TRAP staining. The expression of cyclooxygenase-2 (Cox2), prostanoid receptor EP4 (Ep4) and Rank mRNAs in bone marrow cells were measured using real-time quantitative PCR, while prostaglandin E2 (PGE2 ) production was determined by ELISA.

RESULTS

The levels of IL-1α, IL-1β, TNF-α and IL-6 in IL-1Ra KO mice PM-SF stimulated with A. actinomycetemcomitans LPS were significantly increased by approximately 4- (p < 0.05), 5- (p < 0.05), 1.3- (p < 0.05) and 6- (p < 0.05) fold, respectively, compared with the levels in WT mice. Moreover, osteoclast formation, expression of Rank, Ep4 and Cox2 mRNAs and production of PGE2 were significantly increased by approximately 2- (p < 0.05), 1.6- (p < 0.05), 2.5- (p < 0.05), 1.6- (p < 0.05) and 1.9- (p < 0.05) fold, respectively, in IL-1Ra KO mice stimulated with A. actinomycetemcomitans LPS compared with WT mice.

CONCLUSION

IL-1Ra regulates IL-1 activity and appears to reduce the levels of other inflammatory cytokines, including TNF-α and IL-6, while it also reduces expression of the EP4 receptor related to prostanoid sensitivity and osteoclast formation. These results suggest that IL-1Ra is an important molecule for inhibition of inflammatory periodontal bone resorption.