Azithromycin as an adjunctive treatment of generalized severe chronic periodontitis: clinical, microbiologic, and biochemical parameters.

BACKGROUND: This study examines the efficacy of azithromycin in combination with non-surgical periodontal therapy on clinical and microbiologic parameters and gingival crevicular fluid (GCF) matrix metalloproteinases-8 (MMP-8) levels over 6 months in patients with severe generalized chronic periodontitis (CP). METHODS: Twenty-eight of 36 patients with severe generalized CP were included in this randomized, double-masked, placebo-controlled, parallel-arm study. They were randomly assigned to azithromycin or placebo groups (500 mg, once daily for 3 days). Probing depth (PD), clinical attachment level, dichotomous presence or absence of supragingival plaque accumulation, and bleeding on probing were recorded. GCF samples were obtained from one single-rooted tooth with PD ≥ 6 mm, whereas microbiologic samples were collected from two single-rooted teeth with PD ≥ 6 mm. Microbiologic parameters were analyzed by quantitative real-time polymerase chain reaction for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, and total bacteria. GCF MMP-8 levels were determined by immunofluorescence assay. RESULTS: Azithromycin and placebo groups demonstrated similar but significant improvements in all clinical parameters (P <0.05). A. actinomycetemcomitans, P. gingivalis, T. forsythia, P. intermedia, and total bacteria significantly decreased over the 6-month period in both groups, whereas F. nucleatum was significantly reduced in all visits in the azithromycin group, with the levels also being lower compared with those of the placebo group (P <0.05). The azithromycin and placebo groups exhibited significant reduction in GCF MMP-8 levels at the post-treatment visit and at 2 weeks (P <0.05). CONCLUSION: On the basis of the present findings, it can be concluded that adjunctive azithromycin provides no additional benefit over non-surgical periodontal treatment on parameters investigated in patients with severe generalized CP.

Expression profile of human gingival fibroblasts induced by interleukin-1beta reveals central role of nuclear factor-kappa B in stabilizing human gingival fibroblasts during inflammation.

BACKGROUND: Interleukin (IL)-1beta is a key cytokine in the pathogenesis of periodontitis, and it induces inflammatory mediators in periodontal diseases. We developed immortalized human gingival fibroblasts (HGFs), investigated the effects of IL-1beta on the gene expression using expression arrays containing approximately 40,000 genes, and tested the role of nuclear factor-kappa B (NF-kappaB) in maintaining an activated HGF population. METHODS: Total RNA was isolated from IL-1beta-induced and mock-induced control cells. Gene expression analyses were performed using expression arrays and confirmed by quantitative real-time polymerase chain reaction. Western blot analysis to show inhibitor of kappa B-alpha (IkappaBalpha) phosphorylation and immunostaining of cells for NF-kappaB nuclear translocation were performed. Apoptosis was confirmed by assay of poly ADP-ribose polymerase (PARP) cleavage. RESULTS: A total of 382 probe sets corresponding to 254 genes were differentially expressed in IL-1beta-induced cells (P <0.001). A total of 215 genes were upregulated, and 39 genes were downregulated. Most notable NF-kappaB pathway members (NFkappaB1, NFkappaB2, IkappaBalpha, IkappaBepsilon, IkappaBzeta, REL, RELB, and TA-NFKBH) were upregulated. IkappaBalpha was phosphorylated, and NF-kappaB accumulated in the nucleus. An IL-1beta-induced set of 27 genes was downregulated by an NF-kappaB inhibitor, leading to a decreased number of viable cells and suggesting an antiapoptotic role for NF-kappaB. CONCLUSIONS: IL-1beta leads to a large number of significant expression changes consistent with a pathologic role in periodontitis, including enhancement of inflammatory cytokines, chemokines, transcription factors, matrix metalloproteinases, adhesion molecules, and especially NF-kappaB-dependent antiapoptotic genes. NF-kappaB activation blocks apoptosis, thereby stabilizing the HGF population in inflammation.

Renin-angiotensin gene polymorphisms in relation to severe chronic periodontitis.

AIM: Evidence suggests that the ultimate product of the renin-angiotensin system (RAS), angiotensin II, exerts inflammatory actions. The present study aimed to evaluate the inter-relation between gene polymorphisms of the RAS components; angiotensin converting enzyme (ACE), angiotensinogen (AGT) and angiotensin II type-I receptor (AT1R), and severe chronic periodontitis (CP). MATERIAL AND METHODS: DNA was obtained from peripheral blood of 90 CP patients and 126 periodontally healthy subjects, and the clinical parameters were recorded. ACE I/D, AGT M235T and AT1R A1166C polymorphisms were genotyped by the PCR-RFLP method. Chi-square, anova and logistic regression methods were used in statistical analyses. RESULTS: The frequency of the ACE D allele was significantly lower in the CP group than the healthy group (p(corr)=0.015). CP subjects exhibited increased C allele carriage and C allele frequency of the AT1R gene (p(corr)=0.03 and p(corr)=0.03, respectively). All clinical parameters of CP patients were found to be similar in variant allele-carrying and non-carrying subjects (p>0.05). CONCLUSIONS: The present findings suggest that ACE I/D and AT1R polymorphisms might be associated with susceptibility to CP but not with disease severity. The D allele of ACE I/D might be associated with decreased, whereas the C variant of AT1R A1166C might be associated with an elevated risk for CP in Turkish population.

Angiotensin-converting enzyme (ACE), angiotensinogen (AGT), and angiotensin II type 1 receptor (AT1R) gene polymorphisms in generalized aggressive periodontitis.

AIM: Host response to periodontopathic microorganisms can be modulated by genetic factors. Accumulated evidence highlighted the role of renin-angiotensin system (RAS) in inflammatory response thus potential implication of this molecular system in the pathogenesis of periodontitis can be suggested. The present study investigated common genetic variants of molecules within the RAS family namely angiotensin-converting enzyme (ACE), angiotensinogen (AGT) and angiotensin II type 1 receptor (AT1R) in relation to generalized aggressive periodontitis (G-AgP). METHODS: DNA was obtained from peripheral blood of 103 G-AgP patients and 100 periodontally healthy subjects. ACE I/D, AGT M235T and AT1R A1166C polymorphisms were genotyped by polymerase chain reaction and restriction fragment length polymorphism method. Chi-square, ANOVA and logistic regression were used in statistical analyses. RESULTS: Both ACE I/D and AT1R polymorphisms were similar in G-AgP and healthy groups (p>0.05). G-AgP subjects exhibited decreased AGT TT genotype and T allele frequency as compared to healthy subjects (p<0.05). The same trend was also observed in the nonsmoker subgroup regarding investigated RAS polymorphisms. CONCLUSIONS: Present findings suggest that AGT M235T TT genotype and T allele might be associated with decreased risk for G-AgP in Turkish population.

The effects of selective COX-2 inhibitor/celecoxib and omega-3 fatty acid on matrix metalloproteinases, TIMP-1, and laminin-5gamma2-chain immunolocalization in experimental periodontitis.

BACKGROUND: Matrix metalloproteinases (MMPs) play important roles in tissue-destruction mechanisms-associated periodontitis. MMP-8 and -13 are the predominant collagenases that are important in the extracellular matrix degradation in periodontal tissues. MMP-14 is a membrane-type MMP, whereas laminin-5 indicates basal membrane modification and epithelial induction. The purpose of the present study was to evaluate the effects of celecoxib and omega-3 fatty acid administration on the gingival tissue expression of MMP-8, -13, and -14, tissue inhibitor of MMP (TIMP)-1, and laminin (Ln)-5gamma2-chain in rat experimental periodontitis induced by Escherichia coli endotoxin (lipopolysaccharide [LPS]). METHODS: Experimental periodontitis was induced in rats by repeated LPS injection. Fifty-one adult male Sprague-Dawley rats were divided into six study groups: saline control, LPS, LPS + celecoxib, LPS + therapeutic omega-3 (TO3), prophylactic omega-3 + LPS + omega-3 (P+TO3), and LPS + celecoxib + omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given as a single agent or as combination therapy for 14 days. On day 15, all rats were sacrificed, and gingival tissues were analyzed immunohistochemically for the expression of MMP-8, -13, and -14, TIMP-1, and Ln-5gamma2-chain. Alveolar bone loss was evaluated morphometrically under a stereomicroscope. Data were tested statistically by Kruskal-Wallis and Mann-Whitney tests and Spearman correlation analysis. RESULTS: Alveolar bone loss was significantly higher in all study groups compared to the saline control group (all P <0.01). MMP-8 expression was significantly higher in the LPS group than in the saline group (P = 0.001). Very low expression of MMP-8 was found in the celecoxib, P+TO3, and combination groups. TO3 increased TIMP-1 expression significantly compared to the LPS group (P <0.05). Individual celecoxib and P+TO3 administration increased MMP-14 significantly compared to saline control and LPS groups (P <0.05). No significant differences were found among the study groups with regard to Ln-5gamma2-chain and MMP-13 expressions (P >0.05). CONCLUSIONS: Selective cyclooxygenase-2 inhibitor, prophylactic omega-3 fatty acid, and a combination of these two agents can inhibit gingival tissue MMP-8 expression. Moreover, the individual administration of therapeutic omega-3 may increase gingival TIMP-1 expression in contrast to no effect on MMP-8, -13, and -14 expressions in experimental periodontitis. These experimental findings in a rat model of LPS-induced periodontitis need to be verified by clinical human studies.

Toll-like receptor 2 and 4 gene polymorphisms in generalized aggressive periodontitis.

BACKGROUND: Toll-like receptors (TLRs) recognize exogenous ligands such as lipopolysaccharide and bacterial lipoprotein during the immune responses to pathogens. The aim of the present study was to investigate whether TLR2 and TLR4 gene polymorphisms are related to susceptibility to generalized aggressive periodontitis (GAgP). METHODS: A total of 245 subjects were included in the present study. Genomic DNA was obtained from the peripheral blood of 90 patients with GAgP and 155 periodontally healthy subjects. Probing depth, clinical attachment loss, plaque accumulation, and bleeding on probing were recorded. The TLR2 gene Arg753Gln and Arg677Trp polymorphisms and TLR4 gene Asp299Gly and Thr399Ile polymorphisms were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. The data were analyzed by chi2 and Mann-Whitney U tests and logistic regression analysis. RESULTS: There was no significant difference in the distribution of TLR2 and TLR4 genotypes and allele frequencies between GAgP patients and healthy subjects (P > 0.05). The TLR2 753Gln allele was found in 3.9% of the GAgP patients compared to 6.1% in the healthy group. The GAgP patients and healthy subjects did not show homozygosity for the TLR2 mutant alleles. The TLR2 677Trp mutant allele was not found in any of the subjects; 2.2% of the GAgP patients and 2.9% of the periodontally healthy subjects were identified as having the TLR4 299Gly polymorphic allele. With regard to the TLR4 399Ile polymorphic allele, 1.1% of the GAgP patients and 2.3% of the periodontally healthy subjects had this allele. CONCLUSIONS: The present study failed to find any significant association between the TLR polymorphisms and GAgP, potentially because of the small sample size. To the best of our knowledge, this was the first study to examine the prevalence of these polymorphisms in a Turkish population with aggressive periodontitis.

TLR2 Arg753Gly, TLR4 Asp299Gly and Thr399Ile gene polymorphisms are not associated with chronic periodontitis in a Turkish population.

AIM: Toll-like receptor (TLR) gene polymorphisms could affect the host's ability to respond to microbial pathogens. In this case-control study, the association of TLR2 and TLR4 gene polymorphisms with chronic periodontitis (CP) was investigated. MATERIALS AND METHODS: Genomic DNA was obtained from the peripheral blood of 83 patients with CP and 106 periodontally healthy subjects. The TLR2 Arg753Gly, Arg677Trp and TLR4 Asp299Gly, Thr399Ile gene polymorphisms were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. The data were analysed by a chi2 test, logistic regression analysis and the Mann-Whitney U test. RESULTS: The 753Gln allele was found in 6.1% of the CP patients as compared with 6.6% in the control group (p>0.05). The frequency of the 299Gly and 399Ile allele was 2.4% and 1.8% in CP patients. For the healthy subjects, the frequency was 2.8% for the 299Gly and 2.5% for the 399Ile allele (p>0.05). None of the CP patients or healthy subjects showed homozygosity for the TLR2 and TLR4 alleles. Percentage of sites with bleeding on probing and plaque were significantly higher in 299Gly-positive patients compared with 299Gly-negative patients (p<0.05). CONCLUSION: These results showed that the TLR2 and TLR4 gene polymorphisms studied are not associated with susceptibility to CP in Turkish patients.

Dietary supplementation of omega-3 fatty acid and circulating levels of interleukin-1beta, osteocalcin, and C-reactive protein in rats.

BACKGROUND: In this study, we evaluated the effects of two different regimes of dietary supplementation of omega-3 fatty acid on serum levels of interleukin-1 beta (IL-1beta), osteocalcin (OC), and C-reactive protein (CRP) in experimental periodontitis. METHODS: Experimental periodontitis was induced by repeated injections of Escherichia coli lipopolysaccharide (LPS). Thirty-nine adult male Sprague-Dawley rats were divided into four study groups as follows: an LPS positive control group; a saline (negative) control group; and two different groups with omega-3 fatty acid dietary supplementation, one in which we gave the supplement subsequent to disease induction (TO3) and the other in which the agent was started prior to and continued subsequent to LPS injections (P + TO3). In the TO3 group, omega-3 fatty acid administration was performed for 14 days following induction of experimental periodontitis. In the P + TO3 group, omega-3 fatty acid was given for 14 days prior to the start of LPS injections and was continued for another 14 days subsequent to the induction of experimental periodontitis. On day 15 of the first LPS injection, serum samples were obtained and rats were sacrificed. Serum samples were analyzed for IL-1beta, OC, and CRP concentrations by enzyme-linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non-parametric tests. RESULTS: LPS injection resulted in statistically significantly more bone loss compared to the saline control group (P <0.05). None of the omega-3 fatty acid administration groups showed evidence that this fatty acid was effective in preventing LPS-induced alveolar bone loss. TO3 and P + TO3 groups revealed significantly higher IL-1beta and OC levels than the LPS group (P <0.05). The study groups exhibited no significant differences in the serum CRP levels. CONCLUSIONS: Omega-3 fatty acid administration does not seem to influence circulating levels of CRP. The significantly increased serum OC level observed in both omega-3 fatty acid regimes is curious and could have an effect on bone turnover, as could the further significant increase in serum IL-1beta, which could counteract any osteoblastic induction by OC through promotion of osteoclast activity. The lack of a therapeutic benefit of omega-3 fatty acid in this study, despite the effects on OC and IL-1beta, is difficult to explain, and further studies are required to more fully assess the potential role of this fatty acid in periodontal treatment.

Effects of selective cyclooxygenase-2 inhibitor and omega-3 fatty acid on serum interleukin-1beta, osteocalcin, and C-reactive protein levels in rats.

BACKGROUND: The aim of this study was to evaluate the effects of selective cyclooxygenase-2 inhibitor, celecoxib, and omega-3 fatty acid on serum levels of interleukin 1-beta (IL-1beta), osteocalcin (OC), and C-reactive protein (CRP) in experimental periodontitis. METHODS: Experimental periodontitis in rats was induced by repeated injection of purified lipopolysaccharide (LPS) derived from Escherichia coli endotoxin. Forty-seven adult male Sprague-Dawley rats were divided into five study groups as follows: saline control, LPS, LPS + celecoxib, LPS + omega-3 fatty acid, and LPS + celecoxib + omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given alone or in combination during 14 days of the experimental study period. At the end of the 2-week protocol, serum samples were obtained, and the rats were sacrificed. Serum samples were analyzed for IL-1beta, OC, and CRP concentrations by enzyme-linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non-parametric tests. RESULTS: According to the morphometric measurements, the LPS and drug treatment groups showed significantly higher bone loss than the saline control group (P <0.05). Omega-3 fatty acid, both alone and in combination with celecoxib, revealed significantly higher IL-1beta levels than LPS and celecoxib groups (P <0.05). Individual and combined administration of celecoxib and omega-3 fatty acid significantly increased OC levels compared to the LPS group (P <0.05). There were no significant differences in serum CRP levels. CONCLUSIONS: Celecoxib and/or omega-3 fatty acid administration does not significantly influence circulating levels of CRP. The significantly increased serum OC level observed after individual and combination administration suggests that celecoxib and omega-3 fatty acid may influence bone remodeling and thereby inhibit the progression of alveolar bone resorption. However, the failure to observe any significant inhibition of bone loss in celecoxib- and/or omega-3 fatty acid-treated rats compared to the LPS group suggests that their therapeutic effect may be reduced by other factors, such as increases in serum IL-1beta promoting osteoclast activity.

Effects of Selective Cyclooxygenase-2 Inhibitor and Omega-3 Fatty Acid on Serum Interleukin-1ß, Osteocalcin, and C-Reactive Protein Levels in Rats.

BACKGROUND: The aim of this study was to evaluate the effects of selective cyclooxygenase-2 inhibitor, celecoxib, and omega-3 fatty acid on serum levels of interleukin 1-beta (IL-1ß), osteocalcin (OC), and C-reactive protein (CRP) in experimental periodontitis. METHODS: Experimental periodontitis in rats was induced by repeated injection of purified lipopolysaccharide (LPS) derived from Escherichia coli endotoxin. Forty-seven adult male Sprague-Dawley rats were divided into five study groups as follows: saline control, LPS, LPS + celecoxib, LPS + omega-3 fatty acid, and LPS + celecoxib + omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given alone or in combination during 14 days of the experimental study period. At the end of the 2-week protocol, serum samples were obtained, and the rats were sacrificed. Serum samples were analyzed for IL-1ß, OC, and CRP concentrations by enzyme-linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non-parametric tests. RESULTS: According to the morphometric measurements, the LPS and drug treatment groups showed significantly higher bone loss than the saline control group (P <0.05). Omega-3 fatty acid, both alone and in combination with celecoxib, revealed significantly higher IL-1ß levels than LPS and celecoxib groups (P <0.05). Individual and combined administration of celecoxib and omega-3 fatty acid significantly increased OC levels compared to the LPS group (P <0.05). There were no significant differences in serum CRP levels. CONCLUSIONS: Celecoxib and/or omega-3 fatty acid administration does not significantly influence circulating levels of CRP. The significantly increased serum OC level observed after individual and combination administration suggests that celecoxib and omega-3 fatty acid may influence bone remodeling and thereby inhibit the progression of alveolar bone resorption. However, the failure to observe any significant inhibition of bone loss in celecoxib- and/or omega-3 fatty acid-treated rats compared to the LPS group suggests that their therapeutic effect may be reduced by other factors, such as increases in serum IL-1ß promoting osteoclast activity.

Dietary Supplementation of Omega-3 Fatty Acid and Circulating Levels of Interleukin-1ß, Osteocalcin, and C-Reactive Protein in Rats.

BACKGROUND: In this study, we evaluated the effects of two different regimes of dietary supplementation of omega-3 fatty acid on serum levels of interleukin-1 beta (IL-1ß), osteocalcin (OC), and C-reactive protein (CRP) in experimental periodontitis. METHODS: Experimental periodontitis was induced by repeated injections of Escherichia coli lipopolysaccharide (LPS). Thirty-nine adult male Sprague-Dawley rats were divided into four study groups as follows: an LPS positive control group; a saline (negative) control group; and two different groups with omega-3 fatty acid dietary supplementation, one in which we gave the supplement subsequent to disease induction (TO3) and the other in which the agent was started prior to and continued subsequent to LPS injections (P + TO3). In the TO3 group, omega-3 fatty acid administration was performed for 14 days following induction of experimental periodontitis. In the P + TO3 group, omega-3 fatty acid was given for 14 days prior to the start of LPS injections and was continued for another 14 days subsequent to the induction of experimental periodontitis. On day 15 of the first LPS injection, serum samples were obtained and rats were sacrificed. Serum samples were analyzed for IL-1ß, OC, and CRP concentrations by enzyme-linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non-parametric tests. RESULTS: LPS injection resulted in statistically significantly more bone loss compared to the saline control group (P <0.05). None of the omega-3 fatty acid administration groups showed evidence that this fatty acid was effective in preventing LPS-induced alveolar bone loss. TO3 and P + TO3 groups revealed significantly higher IL-1ß and OC levels than the LPS group (P <0.05). The study groups exhibited no significant differences in the serum CRP levels. CONCLUSIONS: Omega-3 fatty acid administration does not seem to influence circulating levels of CRP. The significantly increased serum OC level observed in both omega-3 fatty acid regimes is curious and could have an effect on bone turnover, as could the further significant increase in serum IL-1ß, which could counteract any osteoblastic induction by OC through promotion of osteoclast activity. The lack of a therapeutic benefit of omega-3 fatty acid in this study, despite the effects on OC and IL-1ß, is difficult to explain, and further studies are required to more fully assess the potential role of this fatty acid in periodontal treatment.

Gingival tissue proteoglycan and chondroitin-4-sulphate levels in cyclosporin A-induced gingival overgrowth and the effects of initial periodontal treatment.

OBJECTIVES: Cyclosporin A (CsA) is a potent immunosuppressive drug used in organ transplant patients to prevent graft rejection. CsA-induced gingival overgrowth is one of the side effects of this drug and its pathogenesis is still unclear. The present study was planned to comparatively analyse total proteoglycan (PG) and chondroitin-4-sulphate (C4S) levels in CsA-induced overgrown gingival tissue samples obtained before and after initial periodontal treatment and to compare these findings with the situation in healthy gingiva. MATERIAL AND METHODS: Gingival tissue samples were obtained from nine patients with CsA-induced gingival overgrowth before and 4 weeks after initial periodontal treatment including oral hygiene instruction and scaling and also from 10 healthy control subjects. Total PG and C4S levels were determined by biochemical techniques. PG levels were analysed using modified Bitter and Muir method. C4S assay was carried out using chondroitin sulphate lyase AC and chondroitin-6 sulphate sulphohydrolase enzymes. The results were tested statistically using non-parametric tests. RESULTS: All clinical measurements in the CsA-induced gingival overgrowth group demonstrated significant reductions 4 weeks after initial periodontal treatment (p<0.05). There was no significant difference between the levels of baseline total PG in CsA-induced gingival overgrowth and healthy control groups (p>0.05). The gingival tissue levels of PG in CsA-induced gingival overgrowth group decreased significantly 4 weeks after treatment (p=0.043). Gingival tissue C4S levels in the overgrowth group were significantly higher than the healthy control group at baseline (p=0.000). C4S levels of the overgrowth group were significantly reduced after treatment (p=0.033), but these levels were still significantly higher than the healthy control group (p=0.000). CONCLUSION: The observed prominent increase in gingival tissue C4S levels may be interpreted as a sign of an increase in C4S synthesis in CsA-induced gingival overgrowth. Furthermore, remission of clinical inflammation by means of initial periodontal treatment had a positive effect on tissue levels of these extracellular matrix molecules.

Individual and combined effects of selective cyclooxygenase-2 inhibitor and omega-3 fatty acid on endotoxin-induced periodontitis in rats.

BACKGROUND: The present study was planned to evaluate the individual and combined effects of selective cyclooxygenase-2 (COX-2) inhibitor, celecoxib, and omega-3 fatty acid on the gingival tissue levels of prostaglandin E2 (PGE2), prostaglandin F2alpha (PGF2alpha), leukotriene B4 (LTB4), and platelet activating factor (PAF) in endotoxin-induced periodontitis in rats. METHODS: Experimental periodontitis was induced by repeated injection of Escherichia coli endotoxin (LPS). Forty-four adult male Sprague-Dawley rats were divided into five study groups: saline control, LPS, celecoxib, omega-3 fatty acid, and combination celecoxib and omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given either as a single agent or as a combination therapy during 14 days of the study period. At the end of the 2-week protocol, the rats were sacrificed, the gingival tissues were dissected and extracted, and the extracts were analyzed for PGE2, PGF2alpha, and LTB4 levels by enzyme immunoassay and for PAF levels by radioimmunoassay. The defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by using parametric tests. RESULTS: LPS injection resulted in significantly more bone loss than the saline controls (P<0.05) and significant elevations in the gingival tissue levels of all the analyzed mediators except PGF2alpha. Individual administration of celecoxib revealed significant reductions in PGE2 and PAF levels (P <0.05), while omega-3 fatty acid provided significant reduction in PGE2, PGF2alpha, and LTB4 levels compared to the LPS group (P <0.05). Combined administration of celecoxib and omega-3 fatty acid exhibited significantly lower values than those of the LPS group in all the analyzed membrane phospholipid mediators (P <0.05), which approximated the levels in the saline control group (P>0.05). CONCLUSIONS: The results of the present study indicate that celecoxib and omega-3 fatty acid, when used individually, show a rather partial effect on the control of the analyzed mediators, but when combined they show a synergic effect and provide significant reductions in the gingival tissue levels of PGE2, PGF2alpha, LTB4, and PAF in LPS-induced experimental periodontitis. These findings may pioneer further clinical human studies investigating the possible place of celecoxib and omega-3 fatty acid in periodontal treatment.

Periodontal infections and pre-term low birth weight: a case-control study.

OBJECTIVE: Pre-term delivery of low-birth-weight infants [pre-term low birth weight (PLBW)] remains a significant public health issue and a major cause of neonatal death and long-term health problems. There is a growing consensus that infections remote from fetal-placental unit may influence PLBW infants. Recent studies have suggested that maternal periodontal disease may be an independent risk factor for PLBW. The purpose of the present study was to evaluate the possible link between periodontal infections and PLBW by means of clinical and microbiological data in post-partum women with low socioeconomic level. METHODS: Clinical periodontal recordings comprising dental plaque, bleeding on probing, probing pocket depth and gingival recession were performed (six sites/tooth) in a total number of 181 women (53 cases and 128 controls) within 3 days post-partum. Subgingival plaque samples from mesio-or disto-buccal aspect of randomly selected one first molar and one incisor tooth have been obtained by paperpoints and were analysed by checkerboard DNA-DNA hybridization with respect to 12 bacterial species. In all analyses, the individual subject was the computational unit. Thus, mean values for all clinical parameters were calculated and bacterial scores from each individual sample were averaged. Statistical methods included Student's t-test, Fisher's exact test/chi(2) test, and multiple logistic regression analysis. RESULTS: The cases have gained significantly less weight during the pregnancy than did the controls (p<0.05). There were no statistically significant differences between the cases and controls with regard to the dental and periodontal parameters and the values of clinical periodontal recordings were found to be very similar (p>0.05). Mean and median scores (bacterial loads) of Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Actinobacillus actinomycetemcomitans, and Streptococcus intermedius in the subgingival plaque sampling sites were significantly higher in the controls than in the cases (p<0.05). The occurrence rates of P. intermedia, Fusobacterium nucleatum, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Selenomonas noxia and S. intermedius were higher in the cases compared with the controls, but the differences were not statistically significant (p>0.05). According to the model created by the multiple logistic regression analysis, P. micros and C. rectus were found to significantly increase the risk of PLBW (p<0.01 and p<0.05 respectively), while P. nigrescens and A. actinomycetemcomitans decreased this risk (p<0.01). CONCLUSION: The present findings indicated that when subgingival bacteria were evaluated together, P. micros and C. rectus may have a role in increasing the risk for PLBW, although no single bacteria exhibited any relation with the risk of PLBW. Further studies are required to better clarify the possible relationship between periodontal diseases and PLBW.

Evaluation of the relationship between smoking during pregnancy and subgingival microbiota.

BACKGROUND: Numerous studies have shown that smoking negatively affects periodontal health. Hormonal changes, which occur during pregnancy have also been reported to have adverse effects on the periodontal tissues or indirectly through alterations in the subgingival bacterial flora. At present, no knowledge exists concerning possible effects of smoking on the composition of subgingival plaque in pregnancy. The purpose of the present study was to evaluate the effects of smoking during pregnancy on the subgingival plaque bacteria most commonly associated with periodontal disease. METHODS: A total number of 181 women were examined within 72 h post-partum. Smoking status was recorded by means of a self-reported questionnaire and the study population was divided into three groups; non-smokers, light smokers, and heavy smokers. In each woman, two subgingival plaque samples were obtained from mesio- or disto-buccal aspect of randomly selected one molar and one incisor tooth by sterile paperpoints. Clinical periodontal recordings comprising presence of dental plaque, bleeding on probing (BOP), and probing pocket depth (PPD) were performed at six sites per each tooth at all teeth. Plaque samples were analysed by checkerboard DNA-DNA hybridization with respect to 12 bacterial species. In all analyses, the individual subject was the computational unit. Thus, mean values for all clinical parameters were calculated and bacterial scores from each individual sample were averaged. Statistical methods included chi2 test, Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: Mean ages were similar in the study groups. Plaque, BOP and PPD recordings were lower in the heavy-smoker group, but the differences were not statistically significant (p>0.05). The detection rates and bacterial loads of the specific subgingival bacteria exhibited no significant differences between the groups. No correlation could be found between smoking status and detection rates and bacterial loads of various bacterial species. CONCLUSION: The present findings suggest that smoking during pregnancy does not have a significant effect on the composition of subgingival plaque bacteria.

Effectiveness of adjunctive low-dose doxycycline therapy on clinical parameters and gingival crevicular fluid laminin-5 gamma2 chain levels in chronic periodontitis.

BACKGROUND: Laminin-5 (Ln-5) is involved in the apical migration of epithelial cells during the development of periodontal pockets. Low-dose doxycycline (LDD) can therapeutically modulate the host response with its non-antimicrobial properties. In the present randomized, double-blind, placebo-controlled, parallel arm study, the effectiveness of LDD in combination with non-surgical periodontal therapy on gingival crevicular fluid (GCF) Ln-5 gamma2 chain fragment levels and clinical parameters in patients with chronic periodontitis was examined over a 12-month period. METHODS: GCF samples were collected and clinical parameters including probing depth (PD), clinical attachment level, gingival index (GI), and plaque index were recorded. Thirty chronic periodontitis patients were randomized either to low-dose doxcycline or placebo groups. LDD group received doxycycline (20 mg, b.i.d.) for 3 months plus scaling and root planing (SRP), while placebo group was given placebo capsules b.i.d. for 3 months plus SRP. The patients were evaluated every 3 months during the 12-month study period. All clinical parameters and GCF sampling were repeated at each visit. GCF Ln-5 gamma2 chain fragment levels were determined by Western immunoblotting using specific antibody and quantitated by computerized image analysis. Friedman test was used for intragroup comparisons followed by Wilcoxon signed rank test to analyze significance of changes over time. The Mann-Whitney test was used to determine differences between both LDD and placebo groups. RESULTS: Both groups revealed significant improvements in all clinical parameters over the 12-month period (P < 0.0125). LDD group showed a significantly greater reduction in the mean PD scores at 9 and 12 months and in the mean GI scores at all time points than the placebo group (P < 0.05). In the LDD group, GCF Ln-5 gamma2 chain fragment levels were significantly reduced at 3 months (P < 0.0125) and then slightly increased during the rest of the study period. In the placebo group, GCF 45 and 70 kDa Ln-5 gamma2 chain fragments tended to decrease at 3 months compared to baseline, but did not reach significance; these levels continued to increase throughout the remainder of the study period. GCF Ln-5 gamma2 chain fragment levels in LDD group were significantly lower than those of the placebo group during the study period (P < 0.05). CONCLUSIONS: The present data indicate that LDD therapy in combination with SRP therapy can reduce GCF Ln-5 gamma2 chain fragment levels and improve clinical periodontal parameters in patients with chronic periodontitis. Since matrix metalloproteinases (MMP)-mediated fragmentation of laminin-5 can contribute to pocket formation by stimulating epithelial cell migration, the reduction of Ln-5 gamma2 chain fragment levels could provide a new mechanism by which LDD, adjunctive to SRP, inhibits periodontal disease more effectively than SRP alone. Thus, these results provide extended and additional information about the effectiveness of the LDD therapy as an adjunct to non-surgical periodontal therapy in the long-term management of periodontal disease.

Total proteoglycan and chondroitin-4-sulfate levels in gingiva of patients with various types of periodontitis.

BACKGROUND: The aim of the present study was to investigate the total proteoglycan (PG) and chondroitin-4-sulfate (C4S) levels in gingival tissue samples obtained from patients with aggressive periodontitis (AgP) and chronic periodontitis (CP) before therapy (baseline) and 1 month after completion of non-surgical periodontal therapy. METHODS: Gingival tissue samples were obtained from 10 AgP and 10 CP patients before initiation of treatment (baseline) and 1 month after non-surgical periodontal treatment. The control group comprised 10 systemically and periodontally healthy subjects. Total PG and C4S levels were determined by biochemical techniques. PG levels were analyzed using a modified Bitter and Muir method. C4S assay was carried out using chondroitin sulphate lyase AC and chondroitin-6 sulphate sulphohydrolase enzymes. The results were tested statistically using parametric tests. RESULTS: The clinical periodontal parameters demonstrated significant decreases in the periodontitis groups (P<0.05) after treatment, and there was no significant difference between AgP and CP groups at baseline and after treatment (P>0.05). At baseline, total PG and C4S levels in both of the periodontitis groups were significantly lower than that of the control group (P<0.05). One month after the non-surgical periodontal treatment, total PG levels in the periodontitis groups were comparable to the control group (P>0.05), whereas C4S levels in the AgP group were significantly lower than the other study groups (P<0.05). In the CP group, total PG and C4S levels increased significantly (P = 0.001 and P = 0.006, respectively) after non-surgical periodontal treatment, but they did not increase in the AgP group (P>0.05). CONCLUSION: The significant increases observed in total proteoglycan and chondroitin-4-sulfate levels after non-surgical periodontal treatment in the CP group but not in the AgP group may suggest that healing patterns differ between the two periodontitis types in terms of PG and C4S composition of extracellular matrix.

The effect of adjunctive low-dose doxycycline therapy on clinical parameters and gingival crevicular fluid matrix metalloproteinase-8 levels in chronic periodontitis.

BACKGROUND: Low-dose doxycycline (LDD) is recognized to have non-antimicrobial properties that can therapeutically modulate the host response. The aim of the present randomized, double-blind, placebo-controlled, parallel-arm study was to examine the effectiveness of LDD in combination with non-surgical periodontal therapy, compared to non-surgical periodontal therapy alone, on gingival crevicular fluid (GCF) matrix metalloproteinase-8 (MMP-8) levels and clinical parameters over a 12-month period in patients with chronic periodontitis. METHODS: GCF samples were collected, and clinical parameters including probing depth (PD), clinical attachment level, gingival index (GI), and plaque index were recorded. Thirty chronic periodontitis patients were randomized either to a low-dose doxycycline (LDD) or placebo group. The LDD group received low-dose doxycycline (20 mg) b.i.d. for 3 months plus scaling and root planing (SRP), while the placebo group was given placebo capsules b.i.d. for 3 months plus SRP. The patients were evaluated every 3 months during the 12-month study period. At each visit, all clinical measurements and GCF sampling were repeated. GCF MMP-8 levels were determined by a time-resolved immunofluorescence assay. Intragroup comparisons were tested by the Friedman test followed by Wilcoxon signed-rank test to analyze significance of changes over time. The Mann-Whitney test was used to determine differences between the LDD and placebo groups. RESULTS: Significant improvements were observed in all clinical parameters in both groups over the 12-month period (P < 0.0125). The LDD group showed a significantly greater reduction in mean PD scores at 9 and 12 months and in mean GI scores at all time points than the placebo group (P < 0.05). From baseline to 12 months, GCF MMP-8 levels were significantly reduced in both groups (P < 0.0125). The GCF MMP-8 level in the LDD group was significantly lower than that of the placebo group at 6 months (P < 0.05). CONCLUSIONS: The present results indicate that low-dose doxycycline therapy in combination with scaling and root planing can reduce GCF MMP-8 levels and improve clinical periodontal parameters in patients with chronic periodontitis. These results provide additional information about the usefulness of low-dose doxycycline therapy as an adjunct to non-surgical periodontal therapy in the long-term management of periodontal disease. The effectiveness and course of low-dose doxycycline therapy can be monitored conveniently by assessing GCF MMP-8 levels.

Therapeutic versus prophylactic plus therapeutic administration of omega-3 fatty acid on endotoxin-induced periodontitis in rats.

BACKGROUND: The aim of the present study was 1) to evaluate the possible effects of therapeutic usage of omega-3 fatty acid on the gingival tissue levels of prostaglandin E2 (PGE2), prostaglandin F2alpha (PGF2alpha), platelet activating factor (PAF), and leukotriene B4 (LTB4) in endotoxin-induced periodontitis in rats and 2) to investigate whether prophylactic usage provides any additional benefits to therapeutic doses of omega-3 fatty acid. METHODS: Experimental periodontitis was induced by repeated injection of Escherichia coli lipopolysaccharide (LPS). Thirty-six adult male Sprague-Dawley rats were divided into four study groups: 1) saline controls; 2) LPS; 3) therapeutic omega-3 fatty acid (TO3); and 4) prophylactic plus therapeutic omega-3 fatty acid (P + TO3) groups. In TO3 group, omega-3 fatty acid was given for 15 days following induction of experimental periodontitis. In P + TO3 group, omega-3 fatty acid was started 15 days before baseline, and then periodontitis was induced at baseline and omega-3 fatty acid was continued for 15 days after baseline. On day 15 after baseline, all rats were anesthetized and sacrificed. PGE2, PGF2alpha, and LTB4 levels in gingival tissue samples were analyzed by enzyme immunoassay and PAF levels were analyzed by radioimmonoassay. Data were evaluated statistically by using parametric tests. RESULTS: LPS injection resulted in significant amount of bone loss (P<0.05). Neither therapeutic nor prophylactic plus therapeutic administration of omega-3 fatty acid with the doses and duration of therapy used in the present study was effective in preventing endotoxin-induced alveolar bone loss. TO3 group exhibited significant decreases in the gingival tissue levels of PGE2, PGF2alpha, LTB4, and PAF compared to the LPS group (P<0.05). PGE2 and PGF2alpha levels in TO3 group were similar to those of the saline group (P>0.05), while LTB4 and PAF levels were statistically higher than the saline group (P<0.05). Prophylactic plus therapeutic usage of omega-3 fatty acid provided similar levels of all these mediators to those of the saline controls (P>0.05). CONCLUSIONS: Therapeutic omega-3 fatty acid significantly reduced the gingival tissue levels of PGE2, PGF2alpha, LTB4, and PAF in experimental periodontitis. Furthermore, prophylactic usage of omega-3 fatty acid provided additional beneficial effects to the therapeutic administration by decreasing the gingival tissue levels of these mediators to levels of healthy tissue. These findings should be verified by longitudinal clinical trials investigating clinical and biochemical periodontal parameters to better define the possible role of omega-3 fatty acids in periodontal treatment.

Effects of selective cyclooxygenase-2 inhibition on gingival tissue levels of prostaglandin E2 and prostaglandin F2alpha and clinical parameters of chronic periodontitis.

BACKGROUND: The purpose of the present study was to evaluate the effect of a relatively selective cyclooxygenase (COX)-2 inhibitor (nimesulide) and non-selective COX-1/COX-2 inhibitor (naproxen) used as an adjunct to non-surgical (scaling and root planing [SRP]) periodontal therapy in chronic periodontitis patients on the gingival tissue (GT) levels of prostaglandin (PG)E2 and PGF2alpha. METHODS: Thirty patients with chronic periodontitis were divided into 3 groups of 10 each. One group received 100 mg of nimesulide; one received 275 mg of naproxen sodium; and the third group received placebo tablets in a 2 x 1 regimen for 10 days as an adjunct to SRP. GT samples were obtained before drug intake and on day 10. Plaque index (PI) and papillary bleeding index (PBI) scores were recorded at baseline, day 10, and at 3 months; probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and at 3 months. The levels of PGE2 were detected using an enzyme immunoassay (EIA), and the levels of PGF2alpha were analyzed by radioimmunoassay (RIA). Differences among and within the groups were assessed using non-parametric statistical analysis. Ten periodontally healthy individuals served as controls. RESULTS: All 3 groups showed statistically significant reductions in PBI and PI on day 10 and at 3 months (P < 0.02), and in PD and CAL at 3 months (P < 0.02, P < 0.05, respectively). In the naproxen group, GT PGE2 levels exhibited a significant decrease (P < 0.05). However, the decrease of GT PGE2 levels in the nimesulide group was insignificant (P > 0.05), while a significant increase was observed in the placebo group (P < 0.05) on day 10. Both the nimesulide and naproxen groups showed a significant decrease (P<0.05) in PGF2alpha level, while the placebo group showed a significant increase (P<0.05). CONCLUSIONS: Nimesulides, relatively selective COX-2 inhibitors, may have additional inhibitory effects on GT PGF2alpha levels in the first week following non-surgical periodontal treatment. However, nimesulide has an insignificant effect on reducing PGE2 levels in gingival tissue. The determination of GT levels of COX-1 and COX-2 enzymes as well as PGE2 and PGF2alpha in long-term studies may provide further support for the adjunctive use of selective COX-2 inhibitors in treatment of chronic periodontitis.