Severe Periodontitis Group Research Articles

The clinical study of IgA nephropathy with severe chronic periodontitis and aggressive periodontitis

To explore the clinical characteristics of IgA nephropathy (IgAN) with severe chronic periodontitis and aggressive periodontitis. A total of 436 hospitalized patients who underwent renal needle biopsy in the department of nephrology of China-Japan Friendship Hospital from November 2013 to December 2014 were recruited in the study and blindly had periodontal examination. The patients were divided into IgAN group and non-IgAN group according to the renal pathology. The patients with IgAN were further categorized as non-periodontitis, chronic periodontitis and aggressive peridontitis group by Haas classification. The chronic periodontitis group was continually divided into mild, moderate and severe periodontitis group. The levels of interleukin (IL)-1β and IL-6 in gingival crevicular fluid were analyzed by enzyme-linked immunosorbent assays. The prevalence of periodontitis in the study was 88.3% (385/436). The prevalence of chronic periodontitis and aggressive periodontitis were higher in patients with IgAN than those with non-IgAN (P<0.05). Degree of chronic periodontitis was correlated with pathologic grading of IgAN (r=0.48, P<0.001). Compared with IgAN patients with other types of periodontitis, those with severe chronic and aggressive periodontitis had more severe pathology, more frequent recurrent gross hematuria, higher levels of 24 h proteinuria, serum triglyceride and uric acid, higher periodontal probing depth and clinical attatchment level, as well as higer levels of IL-1β and IL-6, but had lower creatinine clearance rate (all P<0.05). The prevalence of severe chronic and aggressive periodontitis was higher in patients with IgAN. Chronic periodontitis is correlated with the onset and development of IgAN. Patients with IgAN have worse condition with the aggravation of periodontitis.

Comparative evaluation of probing depth and clinical attachment level using a manual probe and Florida probe.

Background:To compare and evaluate the intra- and inter-examiner efficacy and reproducibility of the first-generation manual (Williams) probe and the third-generation Florida probe in terms of measuring pocket probing depth (PD) and clinical attachment level (CAL).Materials and Methods:Forty subjects/4000 sites were included in this comparative, cross-sectional study. Group- and site-wise categorizations were done. Based on gingival index, PD, and CAL, patients were divided into four groups, i.e., periodontally healthy, gingivitis, mild to moderate periodontitis, and severe periodontitis. Further, based on these parameters, a total of 4000 sites, with 1000 sites in each category randomly selected from these 40 patients, were taken. Full mouth PD and CAL measurements were recorded with two probes, by Examiner 1 and on Ramfjord teeth by Examiner 2.Results:Full mouth and Ramfjord teeth group- and site-wise PD obtained with the manual probe by both the examiners were statistically significantly deeper than that obtained with the Florida probe. The full mouth and Ramfjord teeth mean CAL measurement by Florida probe was higher as compared to manual probe in mild to moderate periodontitis group and sites, whereas in severe periodontitis group and sites, manual probe recorded higher CAL as compared to Florida probe.Conclusion:Mean PD and CAL measurements were deeper with the manual probe as compared to the Florida probe in all the groups and sites, except for the mild-moderate periodontitis group and sites where the CAL measurements with the manual probe were less than the Florida probe. Manual probe was more reproducible and showed less interexaminer variability as compared to the Florida probe.

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.

Clinical implication of blood glucose monitoring in general dental offices: the Ehime Dental Diabetes Study

ObjectiveWe examined whether general dentists can contribute to the detection of patients with undiagnosed diabetes and prediabetes by monitoring blood glucose in dental clinics.Research design and methodsA total of 716...

Periodontitis and retinal microcirculation in the Atherosclerosis Risk in Communities study.

The aim of this cross-sectional study is to explore if periodontitis is associated with alterations of the retinal microcirculation, a predictive marker of cardiovascular events. Of 457 subjects aged 52years and more from the ARIC cohort were included. Retinal vascular diameters were measured and summarized as central retinal arteriolar/venular equivalents (CRAE/CRVE). Periodontitis was determined by using the CDC/AAP definition. Multivariable linear regression models were used to estimate the relationships between CRAE, CRVE and periodontitis. No association was found between CRAE and periodontal status. However, CRVE and severe periodontitis were positively and significantly associated. Mean CRVE (±SD) was 187.0±17.2μm in the health-gingivitis group, and, respectively, 188.5±16.3μm (p=0.39) and 191.6±16.8μm (p=0.04) in moderate and severe periodontitis groups, after adjustment for a propensity score based on confounders. Results were consistent when analyses were restricted to participants with diabetes mellitus (n=66), but not diabetes-free subjects. Severe periodontitis is associated with larger retinal venular diameter in patients with type 2 diabetes. Further studies are needed to explore the impact of diabetes mellitus on the association between periodontitis and retinal microcirculation.

Quantification of tryptase-TIM-3 double-positive mast cells in human chronic periodontitis

ObjectivesMast cells (MCs) are implicated in the pathogenesis of allergic reactions and inflammatory conditions through the release of inflammatory mediators. So far limited attention has been given to the role of MCs in periodontitis. T cell immunoglobulin mucin domain (TIM)-3 is an immunomodulatory molecule and influences MC function. However, whether TIM-3 is expressed on MCs in the process of human periodontal disease has not been reported. Therefore, we identified MCs by toluidine blue staining and examined the expression of TIM-3 on tryptase-positive MCs in different severities of human chronic periodontitis using double-immunofluorescence staining in this study. Material and methodsA total of 83 human periodontal specimens were involved in this study, including healthy control tissues (n=25), chronic moderate periodontitis (n=28), and chronic severe periodontitis (n=30). The gingival specimens were fixed in 10% buffered formalin, stained with haematoxylin and eosin for histopathology, with toluidine blue for MCs, and with double-immunofluorescence for identification of tryptase-TIM-3 double-positive MCs in gingival tissues. ResultsCompared with healthy controls, the score of gingival tissue inflammation was significantly increased in the chronic moderate periodontitis (P=0.013) and chronic severe periodontitis (P<0.0001), and the densities (cells/mm2) of tryptase-TIM-3 double-positive MCs were significantly increased in both the chronic moderate (P=0.011) and severe periodontitis groups (P<0.0001). However, compared with the chronic moderate periodontitis group, both the score of gingival tissue inflammation (P=0.012) and the density of tryptase-TIM-3 double-positive MCs (P=0.011) in gingival tissue were significantly increased in the severe periodontitis groups. ConclusionSignificantly increased number of tryptase-TIM-3 double-positive MCs had the similar tendency as the severity of periodontitis inflammation in human chronic periodontitis. Our data suggest that TIM-3 may have a role on MCs in human chronic periodontitis.

Histological changes within dental pulps in teeth with moderate‐to‐severe chronic periodontitis

To investigate the effect of chronic periodontitis on dental pulps by assessing histological changes in the pulps of teeth with moderate-to-severe periodontitis. A total of 242 teeth from 162 patients with moderate-to-severe periodontitis were collected, and histological changes in pulps were investigated by staining with haematoxylin and eosin. Baseline data were taken from the patients' records before extraction. The morphologic changes observed in the pulp were classified as degree I, degree II, degree III and degree IV. Statistical analysis of the severity of periodontitis and histological changes with the pulps was applied using the Mann-Whitney U rank sum test, whilst the contingency coefficient was used to analyse the inter-relationship between the severity of periodontitis and histological changes in the pulps. The inter-relationship between the severity of periodontitis and histological changes in the pulps was 0.274 (P < 0.001), and significant differences existed between teeth with moderate periodontitis and severe periodontitis group (Z = 4.145, P < 0.001). The inter-relationship between attachment loss and histological changes in the pulps was 0.397 (P < 0.001). There were significant differences in the histological changes amongst teeth with various degrees of attachment loss (χ(2) = 33.023, P < 0.001) and amongst teeth in different locations (χ(2) = 23.163, P < 0.001). There was a positive association between the severity of periodontitis and histological changes within the pulp. More attachment loss was correlated with pathological changes within the dental pulp.

Is the severity of periodontitis related to gingival crevicular fluid and serum high-sensitivity C-reactive protein concentrations?

Periodontitis is a chronic multifactorial inflammatory disease caused by microorganisms and characterized by progressive destruction of the tooth supporting tissues leading to tooth loss. Periodontal diseases are associated with an increase in CRP (C-reactive protein) levels. Release of the cytokines such as prostaglandin-E2 (PGE2), and interleukin-1-beta (IL-1β) from the periodontal lesion, stimulate hepatocytes and circulating leukocytes to produce CRP. The purpose of this cross-sectional study was to evaluate serum levels of hs-CRP (high sensitive C-reactive protein) and gingival crevicular fluid (GCF) levels of hs-CRP, PGE2, and IL-1β in patients with varying degrees of periodontal disease. A total of 60 (30 mild and 30 severe) chronic periodontitis patients were included in this study. GCF and serum samples were collected and whole-mouth clinical periodontal measurements were recorded. GCF levels of hs-CRP, PGE2, IL-1β, and serum levels of hs-CRP were measured by Enzyme-Linked Immunosorbent Assay (ELISA). Serum hs-CRP levels were measured by latex-enhanced immunoturbidimetric assay. Correlation analyses were performed between the sampled site PD, CAL, and the biomarkers. The groups were similar with regard to age, gender, and number of teeth. All periodontal clinical parameters were increased in the severe periodontitis group. GCF IL-1β and PGE2 levels were significantly higher in the severe periodontitis group than in the mild periodontitis group (p = 0.04). Serum and GCF levels of hs-CRP were not significantly different between severe and mild cases. There was no significant correlation between serum and GCF levels of CRP. GCF IL-1β levels were positively correlated with the PD of the sampled site (r = 0.52, p = 0.003). IL-1β in GCF could be a marker of disease severity and activity. Neither serum nor GCF levels of hs-CRP differed with disease severity. Serum hs-CRP levels did not reflect GCF levels in periodontitis patients. Local and systemic involvement of CRP in periodontal disease remains to be determined.

Evaluation of Nonsurgical Treatment Effects on Salivary Melatonin Level in Periodontal Disease: A Radioimmunoassay Study

ABSTRACT Introduction Periodontitis is a chronic inflammatory infection in which tissue destruction is associated with an imbalance between oxidant-antioxidant systems. Melatonin is an antioxidant biomarker that has an antioxidant action. Nonsurgical treatment is one periodontal treatment method that affects etiologic factors. This study investigated salivary melatonin concentration and its changes following nonsurgical treatment in periodontal disease. Materials and methods This study is a case control one where the study groups included 45 patients with periodontal disease and 15 healthy subjects selected as controls. Unstimulated saliva was collected before and after scaling and root planing. Sample was evaluated by radioimmunoassay (RIA) method. In order to analyze the data t-test, ANOVA was used. The p &lt; 0.05 was considered significant. Results Melatonin was detected in study group before nonsurgical treatment. Salivary melatonin levels in the severe periodontitis group were significantly lower than the other groups (p &lt; 0.05). The melatonin changes were statistically significant between the groups of patients after intervention. The significant correlation between salivary melatonin with the clinical parameter was observed (p &lt; 0.05). Conclusion Nonsurgical treatments improve clinical parameters. Salivary melatonin level has correlation with changes in clinical parameters. The melatonin production after nonsurgical treatment had correlation with severity of disease. How to cite this article Hagh LG, Yousefimanesh H, Mohammadi F, Ahangarpour A. Evaluation of Nonsurgical Treatment Effects on Salivary Melatonin Level in Periodontal Disease: A Radioimmunoassay Study. World J Dent 2013;4(4):217-223.

Salivary biomarkers of oral health – a cross‐sectional study

Saliva is a useful diagnostic fluid for oral-related diseases. Monitoring salivary biomarkers for oral and systemic diseases could become an important complement to clinical examinations in epidemiological surveys. Recent findings indicate that it is possible to detect biomarkers for oral diseases within saliva samples. The aim of this study was to investigate if known salivary biomarkers could be used for epidemiological studies for detection of periodontitis. A randomly selected sample of adults (20-89years) living in Southern Sweden were invited to participate. Four hundred and fifty-one individuals were examined clinically using standard examination procedures. Stimulated saliva samples were collected and analysed for concentrations of IL-1β, -6, -8, lysozyme, matrix metalloproteinases (MMP)-8 and tissue inhibitor of metalloproteinase (TIMP)-1 using ELISA, immunofluorometric assay or Luminex assays. Patients with severe periodontitis presented with elevated salivary concentrations of IL-1β (p<0.001) and MMP-8 (p<0.001). In addition, the MMP-8/TIMP-1 ratio was significantly higher in the severe periodontitis group (p<0.001). Smokers compared with non-smokers showed slightly lower concentrations of IL-8 (p<0.05) and MMP-8 (p=0.052). This investigation shows that IL-1β, MMP-8 and the ratio of MMP-8/TIMP-1 could be used as markers of periodontal disease in larger patient populations.

Epidemiological survey on the prevalence of periodontitis and diabetes mellitus in Uyghur adults from rural Hotan area in Xinjiang.

Background and Aims. This study was designed to explore the relationship between periodontitis and diabetes mellitus (DM) in Uygur adults from Xinjiang. Methods and Results. Data were obtained using questionnaire and oral examination. Participants (48.87 ±13.72 yr) were categorized into periodontitis and non-periodontitis groups in accordance with the chronic periodontitis diagnostic criteria. Based on gum inflammation, bleeding on probing, periodontal pocket depth and attachment loss, patients were further divided into mild, moderate and severe periodontitis groups. Among 962 subjects, 453 (47.1%) suffered from chronic periodontitis with a prevalence of type 2 DM and impaired fasting glucose of 9.5% and 11.4%, respectively. In the periodontitis group, the prevalence of type 2 DM was 75.6% compared with 22.4% in the non-periodontitis group. Likewise, the prevalence of impaired fasting glucose was 71.3% and 28.7% in periodontitis and non-periodontitis groups, respectively. The univariate logistic regression analysis revealed moderate and severe periodontitis as risk factors for DM (OR = 3.4, OR = 2.9). Multivariate logistic regression analysis showed that moderate periodontitis is independently associated with DM (OR = 4). Conclusions. Our data revealed that prevalence of DM is overtly higher in periodontitis patients than in individuals without periodontitis. Furthermore, moderate periodontitis is considered an independent risk factor for type 2 DM.

Periodontal disease as a risk for dental implant failure over time: A long-term historical cohort study

To evaluate the long-term survival rates of dental implants according to the patient's periodontal status, as well as to estimate if the effect of periodontal status regarding implant failure is constant throughout the long-term follow-up. This was a historical prospective cohort study design of all consecutive patients operated from 1996 to 2006 at a periodontal clinic. The cohort consisted of 736 patients, with a total of 2336 dental implants. An extended Cox proportional hazards model, which includes interaction terms between survival time and variables of interest, was used. Patients' mean (SD) age was 51.13 (12.35). The follow-up time was up to 144 months, with a mean (SD) of 54.4 (35.6) months. The overall implant raw survival rate was 95.9%. The Kaplan-Meier estimates for the cumulative survival rate (CSR) at 108 months were 0.96 and 0.95 for implants inserted into healthy and moderate chronic periodontal patients, respectively. The CSR declined to 0.88 at 108 months for the severe periodontitis group. The extended Cox model revealed that severe chronic status turned out to be a significant risk factor for implant failure after 50 months of follow-up [hazard ratio (HR)=8.06; p<0.01]. The extended Cox model for smoking indicates a near-significant effect after 50 months (HR=2.76; p=0.061). Periodontal status and smoking are significant risk factors for late implant failures. The HR for periodontal and smoking status are not constant throughout the follow-up period.

Severe Periodontitis Is Associated With Diastolic Blood Pressure Elevation in Individuals With Heterozygous Familial Hypercholesterolemia: A Pilot Study

This pilot study evaluates the association of severe periodontitis with pulse wave velocity (PWV), carotid artery intima-medial thickness (IMT), and clinical, metabolic, and atherogenic inflammatory markers in 79 subjects with heterozygous familial hypercholesterolemia (hFH). All subjects were free of previous vascular disease manifestations. The body mass index (in kilograms per square meter), plasma lipids, glucose, C-reactive protein, and white blood cell counts were evaluated. After full-mouth periodontal examinations, patients were categorized into the severe periodontitis group (SPG) or non-severe periodontitis group (NSPG). The SPG showed significantly higher values of cholesterol-year scores, triglycerides, glucose, PWV, IMT, and diastolic blood pressure (DBP) (P ≤0.05) than the NSPG. After adjustment for traditional risk factors for atherosclerosis, only the association between severe periodontitis and DBP (odds ratio: 3.1; 95% CI: 1.1 to 8.5; P = 0.03) was confirmed. In individuals with hFH, severe periodontitis was associated with a higher DBP, which suggests that severe periodontitis, itself, may contribute to the increased cardiovascular risk profile in this population.

Intracytoplasmic enzymes in gingival crevicular fluid of patients with aggressive periodontitis

Biochemical parameters of crevicular fluid could provide evidence of periodontal tissue disease. The aim of this study was to analyze enzymes in crevicular fluid in aggressive localized and generalized periodontitis. One hundred and twenty-four subjects were classified as having localized (n = 36) or generalized aggressive periodontitis (n = 38) and subclassified into moderate and severe groups. Controls were 50 periodontitis-free subjects. Activities of the enzymes lactate dehydrogenase, neutrophil elastase, alkaline phosphatase and aspartate aminotransferase were determined. Data were analyzed using one-way ANOVA and Tukey's test. Among the subjects with localized aggressive periodontitis, values of lactate dehydrogenase and alkaline phosphatase increased notably in moderate and severe periodontitis compared with control subjects. Values for aspartate aminotransferase increased with the severity of the disease, and neutrophil elastase was increased in the moderate and severe states. In generalized aggressive periodontitis, lactate dehydrogenase showed higher values than in control subjects in both periodontal subgroups. Alkaline phosphatase and neutrophil elastase showed higher significant differences between moderate and severe periodontitis compared with the control group. Aspartate aminotransferase showed differences between the severe and moderate periodontitis groups compared with the control group. Of all the enzymes analyzed, only lactate dehydrogenase showed higher values in localized than in generalized aggressive periodontitis. Lactate dehydrogenase may distinguish localized and generalized aggressive periodontitis. Alkaline phosphatase increases from moderate to severe states in both types of periodontitis. Aspartate aminotransferase and neutrophil elastase only increase with strong evidence of periodontal destruction.

Relationship between transforming growth factor beta-1 gene-509C/T polymorphism and severe chronic periodontitis

To investigate the relationship between transforming growth factor beta-1 (TGF-β(1)) gene-509C/T polymorphism and severe chronic periodontitis in Chinese Hans population. TGF-β(1)-509C/T genotype polymorphism was analyzed in 102 patients with severe chronic periodontitis (periodontitis group) and 102 healthy controls (control group) by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. The distributions of TGF-β(1)-509C/T genotype and allele were significantly different between severe chronic periodontitis group and control group (P < 0.05). TGF-β(1)-509CC, CT and TT genotype frequency were 44.1% (45/102), 47.1% (48/102), 8.8% (9/102) in periodontitis group and 29.4% (30/102), 51.0% (52/102), 19.6% (20/102) in control group, respectively. The relative risk analysis found that C allele carriers had higher risk of suffering from severe chronic periodontitis compared with T allele carriers (OR = 1.718, 95%CI: 1.148-2.569). TGF-β(1)-509C/T polymorphism is associated with severe chronic periodontitis in Chinese Hans population, and C allele may be an important genetic susceptibility gene for severe chronic periodontitis.

Enzymatic Profile of Gingival Crevicular Fluid in Association With Periodontal Status

The diagnosis of periodontal disease can be monitored through the concentration of chemical substances in the gingival crevicular fluid. The objective was to analyze enzymes of the crevicular fluid (neutrophil elastase, alkaline phosphatase, intracytoplasmic lactate dehydrogenase, and aspartate aminotransferase) that could contribute to the clinical diagnosis of different states of gingival-periodontal disease. 115 adults with gingival-periodontal disease and 29 control patients were included. Diagnosis was determined through clinical and radiographic criteria. Samples were obtained from 6 to 8 sites per patient. Elastase in all periodontal groups as compared with the control group, and phosphatase and lactate dehydrogenase as compared to the gingivitis and control groups, increased significantly. Aminotransferase values increased in the severe periodontitis group as compared with the gingivitis and control groups. Quantification of enzymatic biomarkers of periodontal tissue destruction can constitute an appropriate group of parameters for use in clinical practice to distinguish clinical states of gingival-periodontal disease. Elastase could distinguish between the control and gingivitis groups, while alkaline phosphatase and lactate dehydrogenase would change at mild, moderate, and severe periodontitis. Aminotransferase could be evidence of severe periodontitis.

Mannose Binding Lectin Gene Polymorphism and the Severity of Chronic Periodontitis

Mannose binding lectin (MBL) is a key molecule in first line defense against various microorganisms. Polymorphism of the MBL gene greatly affects serum MBL concentration, and is known to be associated with occurrence of infectious diseases. We aimed to determine whether there is a relationship between occurrence or severity of chronic periodontitis (CP) and polymorphism of the MBL gene. Ninety-eight CP patients and 63 healthy subjects with no periodontitis were typed for the codon 54 polymorphism of the MBL gene by PCR-restriction fragment length polymorphism method. Genotype frequencies of the codon 54 polymorphism were similar between patients and control subjects. When patients were categorized to mild, moderate and severe periodontitis groups, possession of the low serum MBL concentration allele was a risk factor for having severe CP, as assessed by logistic regression analysis. Patients with MBL genotypes that cause lower serum MBL concentration may be at risk of having severe periodontitis. MBL gene typing may become useful to predict the prognosis of CP.

Pertinent cell population to characterize periodontal disease

The purpose of this in situ study is to quantify the inflammatory cell subsets and the area fraction (AA%) occupied by collagen fibers in human healthy and diseased (four different stages) gingival connective tissue in order to establish a possible correlation between periodontal disease resulting in collagen breakdown and specific inflammatory cell subsets. Paraffin gingival tissue sections from eight healthy controls (group 0), 10 patients with gingivitis (group 1), 10 patients with moderate periodontitis (group 2) and 10 patients with severe periodontitis (group 3) were immunohistochemically investigated using antibodies against CD-45+, CD-3+, CD-8+, CD-20+, CD-68+, and EMA+ (plasma cells). The AA% occupied by gingival collagen fibers significantly decreased from 54.12% in group (0) to 38.58% in group (1), to 31.87% in group (2), and to 25.46% in group (3). In progressive lesions of periodontal disease, CD-3+ and CD-8+ cell numbers were increased in early stages within the connective tissue, while CD-20+ cell numbers were increased only in late stages. On the other hand, EMA+, CD-68+ and CD-45+ cell numbers were progressively increased from group (0) to group (3). We demonstrated that CD-68+ monocyte/macrophages, CD-45+ leukocyte common antigen and notably EMA+ plasma cells are pertinently correlated with the severity of periodontal disease and related collagen breakdown.

Investigation of matrix metalloproteinase‐1 −1607 1G/2G polymorphism in a Turkish population with periodontitis

Matrix metalloproteinase-1 (MMP-1) is a proteolytic enzyme that degrades extracellular matrix and plays a fundamental role during destruction of periodontal tissues. The aim of this study was to examine the association between MMP-1 -1607 1G/2G polymorphism and chronic periodontitis susceptibility in a Turkish population. A total of 180 subjects were enrolled in this study. All the subjects received a periodontal examination including full-mouth clinical attachment loss measurements, probing depths, plaque index scores, gingival index scores and radiographic bone loss ratios. Three groups formed according to periodontal conditions were healthy, moderate periodontitis and severe periodontitis groups. MMP-1 -1607 1G/2G gene promoter polymorphism was genotyped using a polymerase chain reaction-restriction fragment length polymorphism method. Analysis of the polymorphism showed no differences in distribution of the MMP-1 -1607 1G/2G polymorphism among healthy, moderate periodontitis and severe periodontitis groups (p>0.05). When the groups were further stratified by smoking status, we found no significant differences in genotype distributions, allele frequencies and carriage rates among any groups either (p>0.05). On the basis of the results, no significant association is found for the MMP-1 -1607 1G/2G polymorphism with susceptibility to periodontitis. Moreover, smoking status did not seem to affect this result.

Fractal analysis of dental radiographs to detect periodontitis‐induced trabecular changes

The aim was to evaluate fractal analysis as a tool to quantitatively measure the impact of periodontal disease on surrounding bone. The diagnosis of periodontitis is based on information obtained from clinical and radiographic examinations. The current standard use of dental radiographs is visual inspection, often with no quantitative analysis. Fractal analysis can be used to examine trabecular bone patterns among periodontal patients. Patients (n = 108) from the University of Southern California School of Dentistry were classified into three groups: healthy, moderate and severe periodontitis. A region of interest was selected from periapical radiographs. Image processing was applied to correct for lighting irregularity, and the box-counting method was used to calculate a fractal dimension. ANOVA and ANCOVA were used to measure fractal dimension differences between all groups. According to the statistical tests, significant differences in average fractal dimensions were measured between healthy and moderate periodontitis groups (p < 0.01) and between healthy and severe periodontitis groups (p < 0.001). Higher fractal dimensions were measured in healthy periodontal patients. Fractal analysis evidenced significant differences between patients affected and not affected by periodontitis. The box-counting method quantitatively describes the severity of bone disease and can be used to improve current diagnostic techniques.