Monitoring periodontal disease status in smokers and nonsmokers using a gingival crevicular fluid matrix metalloproteinase-8-specific chair-side test

BACKGROUND AND OBJECTIVE: With current periodontal diagnostic tools it is difficult to identify susceptible individuals or sites at risk. The aim of this study was to evaluate the efficacy of the matrix metalloproteinase (MMP)-8-specific chair-side dip-stick test in longitudinally monitoring the periodontal status of smoking (S) and nonsmoking (NS) patients with chronic periodontitis, using their gingival crevicular fluid (GCF) MMP-8 concentrations. MATERIAL AND METHODS: Clinical parameters, MMP-8 test results and concentrations were monitored in 16 patients after initial treatment and in 15 patients after scaling and root planing (SRP), every other month, over a 12-mo time period. Progressing and stable sites, and sites with exceptionally high MMP-8 concentrations, were analysed in smokers and nonsmokers. RESULTS: SRP reduced the mean GCF MMP-8 levels, test scores, probing depth (PD), attachment loss (AL) and bleeding on probing (BOP). In sites of periodontal disease progression, the distribution of MMP-8 concentrations was broader than in stable sites, indicating a tendency for elevated concentrations in patients with periodontal disease. The mean MMP-8 concentrations in smokers were lower than in nonsmokers, but in smokers' and nonsmokers' sites with progressive disease, MMP-8 concentrations were similar. Sites with exceptionally elevated MMP-8 concentrations were clustered in smokers who also showed a poor response to SRP. In these sites, the MMP-8 concentration did not decrease with SRP and these sites were easily identified by the MMP-8 test. CONCLUSION: Persistently elevated GCF MMP-8 concentrations may indicate sites at risk, as well as patients with poor response to conventional periodontal treatment (e.g. SRP). MMP-8 testing may be useful as an adjunct to traditional periodontal diagnostic methods during the maintenance phase.     

Gingival crevicular fluid collagenase-2 (MMP-8) test stick for chair-side monitoring of periodontitis

BACKGROUND: A rapid chair-side test based on the immunological detection of elevated levels of collagenase-2 (matrix metalloproteinase-8, MMP-8) in gingival crevicular fluid (GCF) was developed to identify and monitor the course and treatment of adult periodontitis. METHODS: MMP-8 was determined in GCF from periodontitis (11 patients, 90 sites), gingivitis (10 patients, 58 sites) and healthy control (8 patients, 59 sites) sites (i) by a test stick incorporating monoclonal antibodies to two epitopes on MMP-8 and (ii) by measuring MMP-8 concentration by a quantitative immunofluorometric assay. Patients with adult periodontitis were treated by scaling and root planing (SRP) and received oral hygiene instructions. GCF MMP-8 testing and clinical measurements were done before and after SRP. RESULTS: MMP-8 GCF levels and chair-side test differentiated periodontitis from gingivitis and healthy control sites. MMP-8 GCF levels > 1 mg/l and positive chair-side test identified especially severe periodontitis sites. A positive and negative test stick result, the outcome of which was rapidly detectable in 5 mins, in GCF correlated well with MMP-8 immunofluorometric assay analysis from the collected GCF samples and the severity of periodontitis. Scaling and root planing reduced the MMP-8 levels in severe periodontitis sites with positive MMP-8 test and gingival probing pocket depth (PD) > 5 mm before treatment. The test stick result and the quantitative assay were discrepant in only 18 of the 207 sites tested, thus agreement was very good (kappa = 0.81). With a threshold of 1 mg/l MMP-8 activity the chair-side test provided a sensitivity of 0.83 and specificity of 0.96 (n = 207). CONCLUSION: The MMP-8 test can be used to differentiate periodontitis from gingivitis and healthy sites as well as to monitor treatment of periodontitis. A reduction in GCF MMP-8 levels and a change in test stick result provide a means to optimize patient control during maintenance of periodontal treatment.     

牙周非手术治疗对龈沟液MMP-8及其抑制剂TIMP-1水平的影响

目的: 比较慢性牙周炎患者非手术治疗前、后龈沟液MMP-8、TIMP-1水平的变化。方法: 选择慢性中重度牙周炎30例, 治疗前、后临床检查牙龈出血指数(SBI)、菌斑指数(PLI)、探诊深度(PD), 采集龈沟液, 采用双抗体夹心ABC-ELISA法检测MMP-8、TIMP-1的含量。采用SSPS 19.0软件包对数据进行配对样本t检验和多元相关分析。结果: 治疗后MMP-8、TIMP-1水平显著下降, MMP-8/TIMP-1 比率治疗前、后无显著差异。多元相关分析各变量间相关性, 发现MMP-8和龈沟液重量呈正相关关系。结论: 牙周非手术治疗能显著降低龈沟液MMP-8、TIMP-1水平, 从而减轻牙周组织损伤。     

MMP-8 analysis in gingival crevicular fluid using ELISA and novel chair-side test

AIM: To validate accuracy of a novel chair-side test for matrix metalloproteinase (MMP)-8 as compared to enzyme-linked immunosorbent assay (ELISA) in Periodontal health and disease. METHODS: Gingival crevicular fluid was collected from 150 subjects, Group 1 (healthy) - 50 subjects, Group 2 (gingivitis) - 50 subjects and Group 3 (chronic periodontitis) - 50 subjects. A chair-side test strip was indigenously prepared using polyclonal antibodies (principle of immunochromatography) to detect the MMP-8 levels. The detection accuracy (sensitivity and specificity) of the MMP-8 levels by chair-side test kit were compared with ELISA at baseline and 3 mo after scaling and root planing among the study population. RESULTS: The novel chair side test detected MMP-8 levels in accordance with ELISA which at baseline were higher in Group 2 and Group 3 as compared to controls (P < 0.05), and these enzyme levels decreased after therapy (P < 0.05). The chair-side test could differentiate healthy, gingivitis and periodontitis. The detection accuracy of the chair-side test strip were on par with ELISA (sensitivity 92.9% and specificity of 100%) which were statistically significant (P < 0.05). A desire to arouse interest about periodontal health and maintenance in the Indian population provided a strong rationale for us to develop our chair-side test strips to suit our economy. Moreover, this was the first ever effort to develop and validate a chair-side test strip to detect MMP-8 levels in the Indian population. This test can be used on a large scale in private dental practice for the early detection of disease, tapping the sites at risk for disease, alongside helps in patient education and motivation for maintenance. CONCLUSION: This study shows that the novel chair side test kit detects MMP-8 levels a biomarker of periodontal disease progression accurately making it a good chair side diagnostic tool. Further, it is cost effective and time saving which can make it applicable in private dental practice on a large scale for the early detection of periodontal disease.     

Interleukin-1 alpha, interleukin-8 and interferon-alpha levels in gingival crevicular fluid

Cytokines play an important role in the pathology associated with chronic inflammatory diseases. We measured the total amounts [picograms (pg)] and concentrations (pg/μl) of interleukin-1 alpha (IL-lα), interleukin-8 (IL-8) and interferonalpha (IFN-α) in 20 s gingival crevicular fluid (GCF) samples obtained from 2 diseased and 2 healthy sites in 20 subjects with periodontitis, and from 2 healthy sites in 20 subjects without disease. Both the mean amount and concentration of IL-lα were significantly higher (p < 0.001) in diseased sites compared to healthy sites in subjects with disease. The results for IL-8 and IFN-α differed depending on the method of reporting. Whereas the amount of IL-8 was significantly higher (p < 0.01) in diseased sites, the mean concentration of IL-8 was lower compared to healthy sites. The mean amount of IFN-α was similar in health and disease; however, the concentration of IFN-alpha was significantly lower in diseased sites (p < 0.001) corresponding to the significant increase in crevicular fluid volume (p < 0.001). There were no significant differences in the amount or concentrations of the 3 cytokines between healthy sites from subjects with disease and healthy sites from healthy controls. The total amounts of both IFN-α and IL-8 were correlated between healthy and diseased sites in subjects. These data suggest that, while the disease status of a site is the major determinant of the levels of these cytokines locally, subjects with high levels of IL-8 and IFN-α in healthy sites also tend to have high levels of these cytokines in diseased sites. Finally, both the concentrations and total amounts of IL-8 and IFN-α were significantly correlated in diseased sites, suggesting that levels of these two cytokines rise or fall in tandem. The combination of decreased IL-8 and decreased IFN-α concentrations at diseased sites may reflect the reduced anti-bacterial host defense activity at that site.     

牙周炎患者龈沟液中IL—1活性检测

目的：通过对牙周炎龈沟液（ｇｉｎｇｉｖａｌｃｒｅｖｉｃｕｌａｒｆｌｕｉｄ，ＧＣＦ）中ＩＬ－１活性进行检测，初步探讨ＩＬ－１在牙周炎症中的作用。方法：以成人牙周炎为研究对象，通过细胞检测法对患牙ＧＣＦ中ＩＬ－１活性进行检测。结果：在患牙ＧＣＦ中可测到具有较高活性的ＩＬ－１，而在健康ＧＣＦ中未能测到。结论：牙周炎时局部有活性ＩＬ－１渗出，ＩＬ－１是参与牙周炎症反应的重要细胞因子。     

牙周炎患者龈沟液中乳酸脱氢酶水平分析

目的：探讨龈沟液中乳酸脱氢酶（ＬＤＨ）水平对于慢性成人牙周炎患者诊断及预后观察的意义。方法：酶动力学方法。结果：患病部位和健康部位龈沟液中ＬＤＨ水平有非常显著差异（Ｐ〈０．００１）。探诊深度和龈沟液中ＬＤＨ水平呈正相关（Ｐ〈０．０５）。附着丧失水平和龈沟液中ＬＤＨ水平呈正相关（Ｐ〈０．０５）。结论：龈沟液中ＬＤＨ水平对于慢性成人牙周炎的诊断和疗效监测具有一定的临床意义。     

Protease activity in gingival crevicular fluid

Abstract. Our aim was to study protease activity in GCF from inflamed sites with or without tissue destruction. 19 patients with both periodontitis and gingivitis sites and 12 patients having gingivitis alone participated in the study. GCF samples were collected by an intracrevicular washing method. The protease activity was measured as degradation of FITC-conjugated casein. To obtain a semiquantitative estimate of the harvested GCF volume, we measured the transferrin concentration in the wash-fluid. The protease activity was significantly higher in the deep pockets in periodontitis patients than in shallow pockets in the same patients. This difference was still higher when the ratio of protease activity to the amount of transferrin in the sample was plotted. Although protease activity was lower in samples from gingivitis patients than in the deep pockets in periodontitis patients, the difference was not significant. About 90% of the activity could be inhibited by the addition of an excess amount of α-1-antitrypsin (A1AT). This study shows that protease activity is higher in inflamed sites with tissue destruction than in inflamed sites without. Most of this activity could be inhibited by A1AT, which suggests that the activity is due to an imbalance between protease and antiprotease rather than to proteases insensitive to A1AT.     

Interleukin-8 and anti-interleukin-8 autoantibodies in gingival crevicular fluid from patients with periodontitis

Interleukin-8 (IL-8) is believed to play an important role in the pathogenesis of various forms of periodontitis. In addition, the anti-IL-8 autoantibody has been recently recognized as a potent modulator of IL-8 function. In the current study, the concentrations of IL-8 and its autoantibody in gingival crevicular fluid from patients with chronic generalized periodontitis were compared to those in gingival crevicular fluid from patients with refractory chronic periodontitis. Gingival crevicular fluids were collected from patients treated in a private periodontal clinic. Nine patients who were identified as having chronic generalized periodontitis and four with refractory chronic periodontitis were selected for the study. Patients included in the latter group had undergone supportive periodontal therapy for more than 10 years, and during that time had experienced many episodes of periodontal destruction. The gingival crevicular fluid concentrations of total protein, IL-8, free anti-IL-8 autoantibody and IL-8 bound to the autoantibody (anti-IL-8:IL-8 complexes) were examined. There were no differences in concentration of total protein, but significantly higher levels of IL-8 were detected in patients with chronic generalized periodontitis in comparison to patients with refractory chronic periodontitis (P < 0.05). In addition, anti-IL-8:IL-8 complexes were present in 90% of patients with chronic generalized periodontitis, but in only 50% of patients with refractory chronic periodontitis. The results suggest that elevated concentrations of free and complexed IL-8 can differentiate patients with chronic generalized periodontitis from patients with refractory chronic periodontitis.     

IDDM牙周病患者龈沟液IL－6的检测与分析

目的：研究胰岛素依赖性糖尿病（IDDM）牙周病患者、单纯牙周病患者和牙周健康者（对照组）龈沟液（GCF）白细胞介素－6（IL－6）水平及其与糖代谢状况的关系。方法：用ELISA法检测龈沟液IL－6水平,同时检测受试者的糖化血红蛋白（HbA1c）浓度。结果：IDDM牙周病组GCF中IL－6水平明显高于单纯牙周病组及对照组。 GCF中IL－6水平与反映糖代谢控制状况的糖化血红蛋白无相关性。结论：糖尿病可使牙周病患者龈沟液IL－6水平显著增高。检测龈沟液IL－6水平的变化,对探讨牙周病发病机制、预防和指导治疗均有一定的临床价值。     

不同金属烤瓷冠及全瓷冠对龈沟液中炎症介质及 MMP- 8 的影响

目的：探讨镍铬合金、钴铬合金、金合金烤瓷冠及IPSE．max全瓷冠修复前后对前牙龈沟液中炎症介质及基质金属蛋白酶-8表达水平的影响。方法：选择牙体缺损需进行全冠修复的上颌前牙80颗并完全随机分为4组（n=20）,分别以镍铬合金、钴铬合金、金合金烤瓷冠及IPSE．max全瓷冠对患牙进行修复。在修复前及修复后6个月分别采集患牙龈沟液标本,用酶联免疫吸附法（ELISA）测定龈沟液中IL-1β、IL-6、TNF-α和MMP-8的含量。使用单因素方差分析、LSD-t检验和配对t检验对数据进行统计学分析。结果：修复后6个月,镍铬合金组和钻铬合金组各项指标较修复前差异有统计学意义（P〈0．05）。其中,镍铬合金组各项数据显著高于钻铬合金组,后者显著高于金合金组（P〈0．05）,而金合金组与全瓷组差异无统计学意义（P〉0．05）。结论：相对于镍铬合金与钴铬合金烤瓷冠,金合金烤瓷冠与IPSE．max全瓷冠对牙龈炎症介质及MMP-8影响较小,具有较好的生物相容性,更适合用于前牙牙体缺损的修复。     

慢性牙周炎患者唾液中miR-146a的表达及其与龈沟炎症、MMP-8/TIMP-1水平的关系

目的： 探讨慢性牙周炎患者唾液中miR-146a的表达及其与龈沟炎症、基质金属蛋白酶8（MMP-8）、基质金属蛋白酶抑制剂1（TIMP-1）水平的关系。方法： 选择2015年3月—2017年1月间收治的慢性牙周炎患者68例作为慢性牙周炎组,同期在本院进行体检的健康志愿者50例作为正常对照组。检测2组研究对象唾液中miR-146a的表达量,龈沟液中炎症因子、MMP-8/TIMP-1的水平及牙周临床症状指标。采用SPSS24.软件中的Pearson检验评估慢性牙周炎患者唾液中miR-146a的表达量与病情严重程度的相关关系。结果： 慢性牙周炎患者唾液中miR-146a的表达量显著高于正常对照组（P<0.05）,龈沟液中炎症因子（IL-1β、IL-6、IL-35、TNF-α）水平、牙周临床症状指标（PD、AL、PLI、BI）以及龈沟液中MMP-8、TIMP-1的水平显著高于正常对照组（P<0.05）。Pearson检验发现,慢性牙周炎患者唾液中miR-146a表达量与龈沟炎症程度、牙周临床症状严重程度及MMP-8/TIMP-1水平呈正相关。结论： 慢性牙周炎患者唾液中miR-146a表达量异常增高,且与龈沟炎症程度、牙周损伤程度一致。     

The effect of topical doxycycline usage on gingival crevicular fluid MMP-8 levels of chronic and aggressive periodontitis patients: a pilot study

Abstract:  The aim of this study was to evaluate the efficacy of topical subgingival application of doxycycline hyclate (DH) gel adjunctive to non-surgical periodontal therapy on gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 levels in chronic and aggressive periodontitis patients. Forty teeth of 10 chronic periodontitis patients and 32 teeth of eight aggressive periodontitis patients were screened for 6 months. Scaling and root planing (SRP) was applied to the control sites and DH gel adjunctive to SRP was applied to the test sites of each patient simultaneously. GCF MMP-8 levels were analysed at baseline, 7 days; and at 1, 3 and 6 months by Sandwich Elisa Method. At 1, 3 and 6 months, probing depth ( P  < 0.0051) and plaque scores and bleeding on probing values ( P  = 0.000) significantly decreased in each group when compared with the baseline, but there was no statistically significant difference between the test and control sites. GCF MMP-8 levels reduced presenting statistically significant differences on 7 days, 1, 3 and 6 months in four of the groups ( P  < 0.05); however, intergroup differences were not statistically significant. Developing functional and immunological-based chair-side MMP tests might serve as useful adjunctive diagnostic tools when monitoring the effects of DH gel application.     

Protein carbonyl levels in serum,saliva and gingival crevicular fluid in patients with chronic and aggressive periodontitis

Objective

This study aims at evaluating the degree of protein carbonyl (PC) levels in serum, gingival crevicular fluid (GCF) and saliva in patients who suffer from chronic periodontitis (CP) and generalized aggressive periodontitis (GAP).

The subgingival microflora and gingival crevicular fluid cytokines in refractory periodontitis

Abstract Refractory periodontitis manifests as a rapid, unrelenting, progressive loss of attachment despite the type and frequency of therapy. This study examined possible relationships between cytokine levels in gingival crevicular fluid (GCF), occurrence of specific periodontopathic microflora. and disease activity in patients with refractory periodontitis. Refractory periodontitis patients (7 male and 3 female) were selected on the basis of history and longitudinal clinical observations. In each patient. 2 teeth with pocket depths greater than 6 mm were selected and individual acrylic stents were fabricated with reference grooves for each site. The sites were examined at both baseline and 3 months later. The pattern and amount of alveolar bone resorption were assayed by quantitative digital subtraction radiography. Pocket depth and attachment loss were measured with a Florida Probe. The gingival index was measured at 4 sites around each sample tooth. Sites were divided into active sites (2.1 mm loss of attachment in 3 months) or inactive sites (2.0 mm loss of attachment in 3 months). The distribution and prevalence of the predominant microflora in active and inactive sites were compared using anaerobic culture and indirect immunofluorescence. Interleukin-1β, 2, 4, 6 and tumor necrosis factor-α (TNF-α) levels in gingival crevicular fluid (GCF) were quantified by ELISA. Prevotella intermedia and Eikenella corrodens significantly decreased in inactive sites but remained the same in active sites after 3 months. The active sites revealed significantly higher GCF levels of IL-2 and IL-6 than inactive sites at both baseline and at 3 months. IL-1β was also significantly greater in active sites than in inactive sites at 3 months. Alveolar bone loss in active sites correlated with increased GCF levels of IL-1β and 1L-β. These results suggest that GCF levels of IL-1β, IL-2 and IL-6 and P. intermedia and E. corrodens in subgingival plaque may serve as possible indicators of disease activity in refractory periodontitis.     

Elastase and lactoferrin in gingival crevicular fluid: possible indicators of a granulocyte-associated specific host response

Periodontitis affects a limited number of susceptible humans. The aim of this study was to determine whether there is a difference in the inflammatory reaction between patients with gingivitis and those with periodontitis. For this purpose the levels of elastase and lactoferrin were measured in gingival crevicular fluid (GCF) from three types of sites: i) inflamed sites in patients with gingivitis alone, inflamed sites both ii) with and iii) without tissue destruction in patients with periodontitis. Elastase activity, measured with a chromogenic substrate was significantly higher in the two types of sites in periodontitis patients. Lactoferrin levels, measured with ELISA were the same in the three types of sites. in vitro activation of granulocytes from healthy volunteers with Fc-receptor stimulation showed that the entire release of lactoferrin occurred immediately. In contrast, elastase release was time-dependent and continued throughout the experiment. Thus, the degranulation of the specific (lactoferrin) and azurophil granule (elastase) are under separate control and the two parameters can be combined in a ratio in order to characterize the granulocytes of a given patient. Assuming an immediate release of lactoferrin from the activated granulocytes in vivo , similar amounts of lactoferrin in the three types of sites can be regarded as reflecting similar numbers of granulocytes in the three types of sites. Consequently, a higher elastase activity in GCF from patients with periodontitis indicates a higher rate of release from the cells per se and a granulocyte-associated specific host response.     

侵袭性牙周炎治疗前后龈沟液CRP、sICAM-1含量测定

目的：测定侵袭性牙周炎龈沟液中C反应蛋白、可溶性细胞间黏附分子1的含量及牙周非手术治疗对其水平的影响,方法：16例侵袭性牙周炎病例,进行非手术治疗,收集治疗前后龈沟液,用酶联免疫吸附法（ELISA法）测定C反应蛋白（CRP）、可溶性细胞间黏附分子1（sICAM—1）水平,并和正常对照组比较。结果：侵袭性牙周炎患者龈沟液中CRP、sICAM-1水平增高,和对照组比较,p〈0．05;牙周非手术治疗后,牙周临床指标明显改善,龈沟液中CRP、sICAM-1水平下降,且接近牙周正常水平。结论：侵袭性牙周炎龈沟液CRP、sICAM-1的水平升高,牙周非手术治疗能有效降低CRP、siCAM-1在龈沟液中的表达。     

Matrix metalloproteinase-8 levels and elastase activities in gingival crevicular fluid from chronic adult periodontitis patients

AIM: To make an initial assessment of the periodontal diagnostic potential of immunoreactive matrix metalloproteinase-8 (MMP-8) in gingival crevicular fluid (GCF) by comparison with elastase activity which has previously been associated with disease severity and progression. METHODS: GCF was collected from molar and premolar sites of 16 chronic adult periodontitis patients before treatment and 13 of this group 2 weeks after scaling and root planing. Samples were analysed for MMP-8 by immunofluorometric assay and for elastase activity with a fluorogenic substrate. RESULTS: Mean patient clinical parameters and GCF enzyme totals both decreased significantly after treatment. Total MMP-8 levels and elastase activities generally correlated significantly with gingival and bleeding indices. For GCF concentrations, only MMP-8 showed a significant fall after treatment, and some significant correlations with clinical parameters. Amounts of the 2 enzymes correlated significantly with each other. CONCLUSIONS: Similarities between MMP-8 and elastase probably reflect the fact that both enzymes are associated mainly with neutrophils: MMP-8 levels may have fallen more after treatment because the assay, unlike that for elastase, would most likely not have detected much enzyme bound to alpha-macroglobulin. The immunoassay for MMP-8 is more specific and convenient than functional collagenase assays, and might be suitable for monitoring the periodontal condition.     

甲硝唑联合羟氨苄青霉素对侵袭性牙周炎患者龈沟液中 MMP-1、MMP-8和 TIMP-1水平的影响

对40例侵袭性牙周炎（AgP）患者（对照组）只行龈下刮治和根面平整术（SRP）,对38例 AgP 患者（研究组）在行 SRP 基础上给予甲硝唑联合羟氨苄青霉素口服7 d。分别于治疗前、治疗后3个月和6个月用酶联免疫吸附法（ELISA）检测患者龈沟液中基质金属蛋白酶-1和8（MMP-1、MMP-8）及基质金属蛋白酶组织抑制物（TIMP-1）的浓度并计算 TIMP-1／MMP-1和 TIMP-1／MMP-8比值。治疗后3个月和6个月,2组患者龈沟液中 MMP-1、MMP-8浓度水平均下降（P ＜0．05）,TIMP-1无显著变化（P ＞0．05）。治疗后2组患者龈沟液中 TIMP-1／MMP-1比值和 TIMP-1／MMP-8比值均明显升高（P ＜0．05）,3月时研究组高于对照组（P ＜0．05）。     

MMP-13 promoter polymorphisms in patients with chronic periodontitis: effects on GCF MMP-13 levels and outcome of periodontal therapy

Aim: The aims of this study were to investigate (a) the matrix metalloproteinase-13 (MMP-13) promoter polymorphisms in severe, generalized chronic periodontitis (CP), (b) the relationship of periodontal therapy outcome with these genotypes and (c) gingival crevicular fluid (GCF) MMP-13 level–MMP-13 genotype correlation.
Materials and Methods: Genomic DNA was obtained from peripheral blood of 102 patients with severe, generalized CP, and 98 periodontally healthy subjects. MMP-13 −77A/G and 11A/12A polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods, respectively. Fifty-eight CP patients received non-surgical periodontal therapy and were followed for 6 months. Clinical periodontal parameters and GCF samples were collected at baseline and at 6 months. GCF MMP-13 levels were analysed by an enzyme-linked immunosorbent assay.
Results: The distribution of MMP-13 −77AG genotypes and allele frequencies did not differ significantly between study groups ( p >0.05). Study subjects, except 3, had the 11A/11A genotype. MMP-13 −77G allele carriers had similar GCF MMP-13 levels and clinical periodontal parameters compared with AA genotypes after non-surgical periodontal therapy ( p <0.05).
Conclusions: These data suggest that the −77A/G and 11A/12A polymorphisms of MMP-13 gene are not associated with susceptibility to severe, generalized CP in a Turkish population. It seems that −77G allele carriage may not influence the outcome of periodontal therapy.