GCF IL-1beta profiles in periodontal disease

Orthodontic Attachments and Chlorhexidine-Containing Varnish Effects on Gingival Health

Objective: To compare the severity of clinical inflammation parameters and the level of the inflammatory mediator interleukin (IL)–1β during orthodontic treatment by using brackets and bands. In addition, the effect of a chlorhexidine-containing varnish was investigated.

Materials and Methods: This prospective randomized controlled trial included 40 healthy children who required an orthodontic treatment of mild crowding. Either brackets or bands were randomly allocated to the premolars with a split-mouth design. Twenty of the children received a chlorhexidine-containing varnish during the treatment (0, 12, 24 weeks), while the remaining children served as a control group. Prior and until 24 weeks after the insertion, data were recorded regarding the pocket depth (PD), the gingival appearance (gingival index [GI]), and the plaque accumulation (plaque index [PI]). Gingival crevicular fluid was collected as well. A quantitative enzyme-linked immunoassay technique was used to detect differences in IL-1β.

Results: The PDs and the gingival index of teeth with brackets showed significantly lower values in comparison with teeth treated with bands (P = .0001). The IL-1β levels confirmed these findings. In contrast, the PI showed higher values for the teeth with brackets (P = .0001). The teeth that received a chlorhexidine-containing varnish showed significantly lower values in the follow-ups for most of the evaluated parameters (PDBand, PIBand, PIBracket, GIBand, GIBracket; P < .015).

Conclusion: The clinically observed parameters as well as the IL-1β levels reflected the higher impact of bands on gingival health. These values showed a significant decrease after application of a chlorhexidine-containing varnish. However, the PI showed higher values for the teeth with brackets.

Effect of periodontal treatment on IL-1beta, IL-1ra, and IL-10 levels in gingival crevicular fluid in patients with aggressive periodontitis

AIM

The aim of this study was to examine the effect of phase I periodontal treatment on the levels of interleukin (IL)-1beta, IL-1ra, and IL-10 in gingival crevicular fluid (GCF) in patients with generalized aggressive periodontitis (G-AgP).

MATERIAL AND METHODS

Data were obtained from 15 patients with aggressive periodontitis and 15 healthy controls. GCF was collected from at least four pre-selected sites (one shallow, at least two moderate, or at least one deep pockets) in patients with G-AgP. In the healthy group, GCF samples were collected from one site. The cytokine levels were determined by an enzyme-linked immunosorbent assay. Probing depth, clinical attachment level (CAL), gingival and plaque indices, and bleeding on probing were measured. The GCF sampling and clinical measurements were recorded at baseline and 6 weeks later after periodontal treatment.

RESULTS

IL-1beta levels were significantly higher at the moderate and deep pocket sites compared with the shallow sites (p<0.05). After periodontal therapy, IL-1beta levels were significantly reduced in the moderate and deep pocket sites (p<0.05). IL-1ra levels at baseline of the moderate and deep pocket sites were significantly lower than the control sites (p<0.05). IL-10 levels were similar in all pockets and did not change after periodontal therapy.

CONCLUSIONS

The periodontal treatment improves the clinical parameters in G-AgP, and this improvement is evident in deep pocket sites for pocket depth and CAL values. These results confirm that IL-1beta is effective for evaluating the periodontal inflammation and can thus be used as a laboratory tool for assessing the activity of periodontal disease.

Analysis of gingival crevicular fluid as applied to the diagnosis of oral and systemic diseases

Gingival crevicular fluid (GCF), a serum transudate or inflammatory exudate, can be collected from the gingival crevice surrounding the teeth. As such, the fluid reflects the constituents of serum, the cellular response in the periodontium, and contributions from the gingival crevice. The study of GCF has focused on defining the pathophysiology of periodontal disease, and identification of a potential diagnostic test for active periodontitis. The majority of markers that have been identified as potential candidates for such a test are measures of inflammation (i.e., prostaglandin E2 (PGE2), neutrophil elastase, and the lysosomal enzyme beta-glucuronidase). Further, analysis of inflammatory markers in GCF may assist in defining how certain systemic disorders (e.g., diabetes mellitus) can modify periodontal disease, and how periodontal disease/periodontal inflammation can influence certain systemic disorders (i.e., cardiovascular/cerebrovascular diseases). Methodological concerns related to the collection and analysis of GCF are important factors that need to be considered when studying GCF. Practical concerns argue against the widespread clinical application of GCF as an adjunct to periodontal diagnosis. Rather, analysis of GCF-derived mediators in saliva may serve as a means of rapid screening for periodontal disease.

Polymorphisms in the CD14 and IL-6 genes associated with periodontal disease

AIM

To compare the frequencies of cytokine and receptor molecule genotypes in patients with chronic periodontitis with the corresponding frequencies in a reference population and to study the relationship between periodontal disease severity and polymorphisms in the studied genes.

SUBJECTS AND METHODS

CD14, IL-6, TNF-alpha, IL-10, IL-1alpha, IL-1beta, and TLR-4 polymorphisms of 51 periodontitis patients were studied using polymerase chain reaction. The genotype frequencies in the periodontitis patients and a reference population (n=178) were compared. Probing pocket depth (PD), periodontal attachment level (AL), and alveolar bone level (BL) were related to the genotypes.

RESULTS

No statistically significant differences could be found between the frequencies of the cytokine genotypes in the periodontitis patients and in the reference group. The extent of periodontal disease was higher in subjects with the T-containing genotype of CD14(-260) and the GG genotype of IL-6(-174) when compared with the extent in the rest of the group. Subjects carrying the composite genotype of the above two were most severely affected by periodontal disease.

CONCLUSION

According to the present results, an evident association exists between the carriage of the T-containing genotype of CD14(-260) and the GG genotype of IL-6(-174) and the extent periodontal disease.

The association of the composite IL-1 genotype with periodontitis progression and/or treatment outcomes: a systematic review

BACKGROUND

Genetically transmitted traits such as cytokine gene polymorphisms may accentuate the host inflammatory response to the bacterial challenge and influence susceptibility to periodontitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A-889 and in IL-1B +3953, and periodontitis progression and/or treatment outcomes.

MATERIAL AND METHODS

Based on the focused question, a search was conducted for longitudinal clinical trials comparing progression of periodontitis and/or treatment outcomes in IL-1 genotype-positive (carrying allele 2) and IL-1 genotype-negative (not carrying allele 2) subjects. A search in the National Library of Medicine computerized bibliographic database MEDLINE and a manual search were performed. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 122 titles of which 11 longitudinal publications were included. The heterogeneity of the data prevented the performance of a meta-analysis. While findings from some publications rejected a possible role of IL-1 composite genotype on progression of periodontitis after various therapies, other reported a prognostic value for disease progression of the positive IL-1 genotype status. When assessed on a multivariate risk assessment model, several publications concluded that the assessment of the IL-1 composite genotype in conjunction with other covariates (e.g. smoking and presence of specific bacteria) may provide additional information on disease progression. The small sample size of the available publications, however, requires caution in the interpretation of the results.

CONCLUSION

Based on these findings, (i) there is insufficient evidence to establish if a positive IL-1 genotype status contributes to progression of periodontitis and/or treatment outcomes. Therefore, (ii) results obtained with commercially available tests should be interpreted with caution.

Gingival crevicular fluid interleukin-1?, prostaglandin E2and periodontal status in a community population

AIM

Interleukin-1 beta (IL-1beta) and prostaglandin E(2) (PGE(2)) are key inflammatory mediators involved in periodontal disease. The purposes of this molecular cross-sectional epidemiological study were to investigate relationships in a community sample between mean concentrations of IL-1beta and PGE(2) in gingival crevicular fluid (GCF) and (1) clinical periodontal signs and (2) risk factors of host inflammatory response and/or periodontal disease.

MATERIAL AND METHODS

The sample comprised 6277 community-dwelling adults aged 52-74 years enrolled in the Atherosclerosis Risk in Communities (ARIC) study. IL-1beta and PGE(2) concentrations were measured using enzyme-linked immunosorbent assay. Person-level summary variables were computed for maximum pocket depth (MaxPD), maximum clinical attachment level (MaxCAL) and presence/absence of bleeding on probing (BOP). Mean GCF IL-1beta and PGE(2) concentrations were dependent variables in multiple linear regression models with periodontal measures and covariates as explanatory variables.

RESULTS

Both GCF IL-1beta and PGE(2) were positively related to MaxPD and BOP in multiple regression models (p<0.01). Increased levels of IL-1beta and PGE(2) were associated with body mass index >or=30 kg/m(2).

CONCLUSION

Higher levels of GCF IL-1beta and PGE(2) were significantly associated with clinical signs of periodontal disease and independently related to patient-based anthropomorphic measures, behaviours and exposures in community-dwelling adults.

Comparison of clinical, radiographic and immunological parameters of teeth and different dental implant platforms

A comparison between host response in teeth and dental implants was not made. Likewise, the association between host response and periodontal parameters has never been explored. The purpose of this study was to compare periodontal health around natural teeth and dental implants with different restorative platforms. Twenty-seven partially edentulous patients with dental implants, either external hex butt joint (n=28) or tapered Morse (n=45), were included in this study. Implants were in function for 1-6 years (mean 2.9). Plaque index (PI), gingival index (GI), probing depth (PD); and clinical attachment level (CAL), were recorded at final examination; alveolar bone loss (ABL) was measured at baseline and final examination using panoramic radiographs. Gingival crevicular fluid samples were obtained from the Ramfjord index teeth and all implants and assayed using enzyme-linked immunosorbent assay for prostaglandin E(2) (PGE(2)), interleukin-1 (IL-1) and tumour necrosis factor alpha (TNFalpha). Differences between teeth and implants and between the two implant platforms were compared using Student's t-test. Correlations between cytokines, ABL and clinical parameters were analyzed using Pearson's co-efficient test. PI and GI were significantly higher in teeth than dental implants (1.2+/-0.5 vs. 0.8+/-0.5, P=0.0018; 1.2+/-0.3 vs. 1.1+/-0.3, P=0.048). Conversely, PD was deeper in implants (2.66+/-0.6 vs. 3.66+/-0.9, P=0.001). GI and PD around teeth and implants were positively associated (R=0.561, P=0.0023; R=0.39, P=0.0452). Greater ABL was observed around dental implants (1.62+/-2.2 mm) compared with teeth (0.49+/-0.3 mm). A positive correlation was found between both IL-1 (R=0.73, P=0.0064; R=0.52, P=0.0081) and TNFalpha (R=0.64, P=0.0246; R=0.46, P=0.091) and ABL in teeth and implants. Both implant platforms were similar clinically and radiographically; however, TNFalpha (2.49+/-0.3 vs. 4.79+/-0.5, P=0.004) and IL-1 (24.52+/-7.3 vs. 45.41+/-9.9, P=0.095) were higher for the non-submerged implants. In conclusion, IL-1 and TNFalpha are sensitive markers of ABL around teeth and implants. The two dental implant platforms showed a similar clinical and radiographic response; however, the greater host response in the non-submerged implants might suggest future bone loss.

Plasma levels of tumour necrosis factor-alpha in patients with chronic periodontitis and type 2 diabetes

OBJECTIVES

Studies suggest that elevated circulating tumour necrosis factor-alpha (TNF-alpha) may contribute to insulin resistance in patients with type 2 diabetes. The source of plasma TNF has been thought to be adipocytes associated with obesity, but inflammation and infection result in TNF-alpha production as well.

METHODS

We studied 46 patients with type 2 diabetes and chronic periodontitis to determine the relationship between plasma TNF-alpha levels and clinical measures of periodontitis, gingival crevicular fluid (GCF) interleukin-1beta (IL-1beta), plasma endotoxin, serum glucose, and glycated haemoglobin (HbA1c). TNF-alpha levels were measured using a high sensitivity enzyme-linked immunosorbent assay.

RESULTS

TNF-alpha showed a significant positive correlation with attachment loss (r=0.40, p=0.009), plasma endotoxin (r=0.33, p=0.03), and GCF IL-1beta (r=0.33, p=0.035), but not probing depth (r=0.28, p=0.07), bleeding on probing (r=0.30, p=0.053), plaque index (r=0.22, p=0.17), serum glucose, HbA1c (r=0.10, p=0.50), or body mass index (r=0.077, p=0.62). A dose-response relationship was observed between periodontitis severity and TNF-alpha (p=0.012).

CONCLUSION

The finding that chronic periodontitis is associated with plasma TNF-alpha levels in subjects with type 2 diabetes supports the hypothesis that periodontal infection and inflammation may contribute to insulin resistance.

Innate immune signaling and Porphyromonas gingivalis-accelerated atherosclerosis

Periodontal diseases are a group of diseases that lead to erosion of the hard and soft tissues of the periodontium, which, in severe cases, can result in tooth loss. Anecdotal clinical observations have suggested that poor oral health may be associated with poor systemic health; however, only recently have appropriate epidemiological studies been initiated, with defined clinical endpoints of periodontal disease, to address the association of periodontal disease with increased risk for cardiovascular and cerebrovascular disease. Although conflicting reports exist, these epidemiological studies support this connection. Paralleling these epidemiological studies, emerging basic scientific studies also support that infection may represent a risk factor for atherosclerosis. With P. gingivalis as a model pathogen, in vitro studies support that this organism can activate host innate immune responses associated with atherosclerosis, and in vivo studies demonstrate that this organism can accelerate atheroma deposition in animal models. In this review, we focus primarily on the basic scientific studies performed to date which support that infection with bacteria, most notably P. gingivalis, accelerates atherosclerosis. Furthermore, we attempt to bring together these studies to provide an up-to-date framework of emerging theories into the mechanisms underlying periodontal disease and increased risk for atherosclerosis, as well as identify intervention strategies to reduce the incidence of periodontal disease in humans, in an attempt to decrease risk for systemic complications of periodontal disease such as atherosclerotic cardiovascular disease.

Salivary biomarkers of existing periodontal disease: a cross-sectional study

BACKGROUND

The authors conducted a study to determine if salivary biomarkers specific for three aspects of periodontitis--inflammation, collagen degradation and bone turnover--correlate with clinica features of periodontal disease.

METHODS

The relationship between periodontal disease and the levels of interleukin-1 beta (IL-1beta), matrix metalloproteinase (MMP)-8, and osteoprotegerin (OPG) in whole saliva of 57 adults (28 "case" subjects with moderate-to-severe periodontal disease and 29 healthy control subjects) was examined in a case-control trial.

RESULTS

Mean levels of IL-1beta and MMP-8 in saliva were significantly higher in case subjects than in controls. Both analytes correlated with periodontal indexes, whereas, after adjustment for confounders, OPG did not. Elevated salivary levels of MMP-8 or IL-1beta (more than two standard deviations above the mean of the controls) significantly increased the risk of periodontal disease (odds ratios in the 11.3-15.4 range). Combined elevated salivary levels of MMP-8 and IL-1beta increased the risk of experiencing periodontal disease 45-fold, and elevations in all three biomarkers correlated with individual clinical parameters indicative of periodontal disease.

CONCLUSION

Salivary levels of MMP-8 and IL-1beta appear to serve as biomarkers of periodontitis.

CLINICAL IMPLICATIONS

Qualitative changes in the composition of salivary biomarkers could have significance in the diagnosis and treatment of periodontal disease.

Association of the IL-1RN2 allele with periodontal diseases

OBJECTIVES

Interleukin-1 receptor antagonist (IL-1Ra) gene (IL-1RN) polymorphism is associated with disease susceptibility and activity in several inflammatory diseases. The aim of this study was to investigate IL-1RN genotype and its associations with different periodontal diseases in a group of Turkish subjects.

DESIGN AND METHODS

A total of 293 subjects were included in this study. Genomic DNA was obtained from the peripheral blood of 52 patients with generalized aggressive periodontitis (G-AgP), 51 with chronic periodontitis (CP) and 190 reference subjects. A variable number tandem repeat (VNTR) polymorphism in the second intron of the IL-1RN gene was detected by PCR-based methods. Probing pocket depth, clinical attachment loss, plaque accumulation and bleeding on probing (BOP) were recorded. The data were analyzed by the chi(2) test, logistic regression and Mann-Whitney U test.

RESULTS

There were significant differences among the groups in the distribution of IL-1RN genotypes (P = 0.0001) and allele frequencies (P = 0.0001). The frequency of IL-1RN2 allele 2 positivity was higher in the AgP and CP group than the reference group [odds ratio (OR) 6.654, 95% CI: 3.023-16.648; OR 10.327, 95% CI: 4.758-22.412, respectively]. The percentage of sites with BOP was significantly higher in IL-1RN2+ compared to IL-1RN2- CP patients (P = 0.022).

CONCLUSION

These results suggest that IL-1RN2 allele positivity is associated with periodontal disease in a Turkish population.

Hyper-reactive mononuclear cells and neutrophils in chronic periodontitis

OBJECTIVES

Stimulated mono- and polymorphonuclear cells from patients with periodontitis have shown increased release of interleukin-1beta (IL-1beta) and oxygen radicals, respectively. The aim was to study whether this hyper-reactivity could be found both in mono- and polymorphonuclear cells from the same patient, and whether there was a relation to the gene coding for IL-1beta (IL-1beta(+3953)).

MATERIAL AND METHODS

Peripheral mononuclear cells from 14 non-smoking and well-treated patients and pair-matched controls were incubated with opsonized Staphylococcus aureus and lipopolysaccharide (LPS). Released IL-1beta and tumour necrosis factor (TNF)-alpha were determined with ELISA. Generation of oxygen radicals from the Fcgamma-receptor-stimulated neutrophils was measured with chemiluminescence and the polymorphism at IL-1beta(+3953) was measured with polymerase chainreaction.

RESULTS

The mononuclear cells from the patients released more IL-1beta after incubation with LPS (p<0.001) and with bacteria (p<0.05). The release of TNF-alpha tended to be higher in the patient group. The peripheral neutrophils from the patients generated more oxygen radicals (p<0.06). We found no differences between the study groups regarding the IL-1beta(+3953) polymorphism.

CONCLUSION

The similarity in systemic inflammation between patients and controls suggests that the increased release/generation of IL-1beta and oxygen radicals from peripheral leukocytes in periodontitis patients is of a constitutional nature and of pathogenic relevance.

Effect of genetic variability on the inflammatory response to periodontal infection

AIM

To review the association between genetic variability and the inflammatory response induced by periodontal infection.

MATERIAL AND METHODS

A search of MEDLINE-PubMed was performed from January 2000 up to and including March 2005. The search included all types of publications, published in English without other limitations. The following search terms were used: "cytokine polymorphism", "gene polymorphism", "periodontitis", "gingivitis", "inflammation" and "host-response". The papers resulting from the above search were used as an additional source for relevant articles.

RESULTS

Genetic variability was examined for the correlation to clinical indicators of inflammation such as bleeding on probing (BOP), gingival inflammation, cytokine in gingival crevicular fluid (GCF) and cytokine production by inflammatory cells. According to the current literature, most of the studies found no association between genetic variability and BOP, gingival inflammation or cytokine concentrations in the GCF. These studies were hampered by inappropriate study designs and the use of inflammatory parameters as secondary rather than primary outcome variables. The data suggest that the production of inflammatory mediators by inflammatory cells may be affected by different genetic traits but further studies are needed in order to establish this association.

CONCLUSIONS

To date, there is no clear correlation between any of the gene polymorphisms and clinical indicators of inflammation. The powering of studies to reveal associations between single or multiple nucleotide polymorphisms and inflammatory parameters will need to involve a much larger number of subjects than were used in the past. The available data (including the interleukin-1 composite genotype) do not currently support the utility of such tests in the diagnosis and prognostic assessments of periodontal diseases.

Diagnostic biomarkers for oral and periodontal diseases

This article provides an overview of periodontal disease diagnosis that uses clinical parameters and biomarkers of the disease process.This article discusses the use of biomarkers of disease that can be identified at the tissue, cellular, and molecular levels and that are measurable in oral fluids such as saliva and gingival crevicular fluid. Biomarkers identified from these biologic fluids include microbial, host response, and connective tissue-related molecules that can target specific pathways of local alveolar bone resorption. Future prospects for oral fluid-based diagnostics that use micro-array and microfluidic technologies are presented.

Oral health in women with coronary heart disease

BACKGROUND

Over the last few decades, oral diseases including periodontitis, have been discussed as a possible risk factor for cardiovascular disease. The purpose of this study was to compare the oral health of age-matched women with or without coronary heart disease (CHD).

METHODS

A total of 143 consecutive women, aged 43 to 79 years, with diagnosed CHD underwent a thorough dental examination including a panoramic radiograph and were compared to 50 women, aged 45 to 77 years without CHD.

RESULTS

The number of remaining teeth and pathological periodontal pockets (> or =4 mm) between the groups differed. The women with CHD had 18.9 +/- 8.5 remaining teeth versus 23.4 +/- 6.3 teeth in the control group (P < 0.001). The CHD group had more pathological periodontal pockets compared to the controls, 14.2 +/- 12.4 versus 9.6 +/- 13.3 (P = 0.002), respectively. The mean marginal bone level assessed on radiographs was the same in both groups, while the number of vertical bone defects differed (P = 0.022). Dentures were more frequent in the CHD group than in the controls (27% versus 6%, P = 0.022), as was edentulousness, 10.5% versus 0% (P = 0.017), respectively. Multiple regression analysis adjusted for age, smoking, body mass index (BMI), diabetes, education, and place of birth showed a relation between the number of periodontal pockets and CHD with an odds ratio (OR) of 3.8 (1.68 to 8.74), and a tendency between dentures and CHD, with an OR of 4.6 (0.99 to 21.28).

CONCLUSION

This study indicates that women with CHD have worse oral health than those in a comparable group with no history of CHD.

Gingival crevicular fluid levels of interleukin-1beta and glycemic control in patients with chronic periodontitis and type 2 diabetes

BACKGROUND

Patients with diabetes have increased incidence and severity of periodontal disease not accounted for by differences in the subgingival microbial infection. Poor glycemic control has been consistently associated with periodontal disease severity. Also, recent evidence suggests that hyperglycemia may induce inflammatory cytokine production. Few studies, however, have examined local biochemical measures of periodontal inflammation in patients with type 2 diabetes. The aim of this study was to determine whether glycemic control was related to gingival crevicular fluid (GCF) levels of interleukin-1beta (IL-1beta).

METHODS

GCF samples were collected from 45 patients with type 2 diabetes and untreated chronic periodontitis. Plaque index (PI), bleeding on probing (BOP), probing depth (PD), and attachment level (AL) were recorded at six sites per tooth. IL-1beta levels were determined from individual GCF samples by enzyme-linked immunoabsorbent assay (ELISA). Individual site and mean patient values were calculated. Glycated hemoglobin (HbA1c) levels were measured from anticoagulated whole blood using an automated affinity chromatography system. Serum glucose was also determined.

RESULTS

Clinical periodontal measures (PD, AL, BOP) and measures of glycemic control (HbA1c, random glucose) were significantly correlated with GCF IL-1beta. Patients with greater than 8% HbA1c had significantly higher mean GCF IL-1beta levels than patients with less than 8% HbA1c. In a multivariate model adjusting for age, gender, PD, AL, BOP, and PI, HbA1c and random glucose were independent predictors of high GCF IL-1beta.

CONCLUSIONS

Poor glycemic control is associated with elevated GCF IL-1beta. These data are consistent with the hypothesis that hyperglycemia contributes to an heightened inflammatory response, and suggests a mechanism to account for the association between poor glycemic control and periodontal destruction.

Effect of periodontal therapy on crevicular fluid interleukin-1beta and interleukin-10 levels in chronic periodontitis

OBJECTIVES

This study aimed to analyse the levels of the proinflammatory cytokine IL-1beta and the anti-inflammatory cytokine IL-10 in gingival crevicular fluid (GCF) of patients with chronic periodontitis prior to, and following, periodontal therapy for a period of 32 weeks.

MATERIAL AND METHODS

GCF samples were obtained from 24 non-diseased and 72 diseased sites of 12 periodontal patients prior to as well as at 6, 16 and 32 weeks post-periodontal therapy. All sites received conventional periodontal treatment and IL-1beta and IL-10 levels (concentration and total amount) were determined by enzyme linked immunosorbent assay (ELISA). Additionally, probing pocket depth (PD), clinical attachment loss (CAL), gingival (GI) and plaque (PII) indices were evaluated pre-and post-therapy.

RESULTS

IL-1beta was detected in 382 out of 384 samples, while IL-10 was detected in 337 out of 384 samples. The total amount of IL-1beta was significantly higher at diseased compared to non-diseased sites (p<0.01). Following therapy, IL-1beta total amounts were reduced, while IL-1beta concentration gradually increased. IL-10 total amounts (per 30 s sample) were similar in diseased and non-diseased sites, and following therapy they remained almost unchanged. By contrast, IL-10 concentration was significantly higher in non-diseased sites (p<0.01) and displayed a significant increase post-therapy. Moreover, IL-1beta concentration and total amount were significantly greater in smokers following therapy, while IL-10 total amount was significantly higher in non-smokers both prior to and following therapy. Total IL-1beta amounts were positively correlated with GI and Pll. A weak negative correlation between IL-1beta and IL-10 levels was noted (p<0.05).

CONCLUSIONS

The data suggest that the total amount rather than the concentration of IL-1beta in GCF seemed to be closely associated with periodontal disease severity. Moreover, smoking status influenced IL-1beta and IL-10 levels. An inverse relationship between IL-1beta and IL-10 was evident.

Bone resorbing activity and cytokine levels in gingival crevicular fluid before and after treatment of periodontal disease

BACKGROUND

The aim of the present study was to investigate bone resorption activity (BRA), interleukin-1 alpha (IL-1 alpha), IL-1 beta and interleukin-1 receptor antagonist (IL-1ra) in gingival crevicular fluid (GCF) in sites with no signs of periodontal disease and in sites with horizontal or angular loss of periodontal bone. These assessments were performed before and after periodontal treatment.

METHODS

GCFs were collected from 10 individuals with filter strips from two healthy sites and four sites with deep pathological periodontal pockets, two of which showed horizontal bone loss and two with angular bone loss. All diseased pockets were treated with flap surgery and systemic Doxyferm. Twelve months later GCF was collected again and treatment outcome evaluated. BRA in GCFs was assessed in a bone organ culture system by following the release of (45)Ca from neonatal mouse calvariae. The amounts of IL-1 alpha, IL-1 beta and IL-1ra in GCFs were quantified by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Treatment resulted in reduction of pocket depths with 3.5+/-0.5 mm in sites with angular bone loss and 2.8+/-0.3 mm in sites with horizontal bone loss. Initially, BRA, IL-1 alpha, IL-1 beta and IL-1ra were significantly higher in GCFs from diseased sites compared with healthy sites. No differences in BRA and cytokine levels were seen between GCFs from pockets with horizontal and angular bone losses. The levels of IL-1 alpha, IL-1 beta and IL-1ra were significantly reduced after treatment of diseased pockets. Pocket depths were significantly correlated to BRA only in pre-treatment sites with angular bone loss. BRA was correlated to Il-1 alpha, IL-1 beta, but not to IL-1ra, in diseased sites with angular bone loss, before and after treatment. The reductions of BRA in the individual sites, seen after treatment, were not correlated to the reductions of Il-1 alpha, IL-1 beta or IL-1ra.

CONCLUSIONS

These data show that BRA and cytokine levels are increased in GCFs from sites with periodontal disease and that periodontal treatment results in reduction of the cytokines. Our findings further indicate that IL-1 alpha and IL-1 beta play important roles for the BRA present in GCFs, but that other factors also contribute to this activity.

Effects of continuous and interrupted orthodontic force on interleukin-1beta and prostaglandin E2 production in gingival crevicular fluid

The purpose of this study was to evaluate the effects of a light continuous force and an interrupted force with weekly reactivation on interleukin-1beta (IL-1beta) and prostaglandin E(2) (PGE(2)); possible interactions between these 2 potent mediators of the bone resorption process were assessed in vivo. Ten healthy young adults (mean age 20.6 years, 2 men, 8 women) with 4 premolars extracted were assessed. In each subject, 1 maxillary canine (E1) received continuous force with a nickel-titanium coil spring. The opposite canine (E2) received an interrupted force with a screw-attached retractor; the force was reactivated weekly by 2 turns of the screw. An antagonistic canine was used as a control. Gingival crevicular fluid was collected from the distal side of each tooth, 10 times in 3 weeks, and IL-1beta and PGE(2) levels were measured. For E1, the IL-1beta level showed a significant elevation at 24 hours and then decreased and maintained an insignificant but high mean concentration, compared with the control site. The PGE(2) level showed a significant elevation at 24 hours and then decreased. For E2, a significant elevation of IL-1beta level was observed at 24 hours and a greater significant elevation at 24 hours after the first reactivation, compared with the control sites. The PGE(2) level increased significantly at 24 hours and remained high for 1 week. The synergistic up-regulation of PGE(2) by appliance reactivation and secreted IL-1beta was not evident with either type of force after 1 week. Both experimental sites showed significant tooth movement compared with the control sites at 3 weeks; however, there was no significant difference between the 2 experimental sites. A well-controlled mechanical stress with timely reactivation can effectively upregulate IL-1beta secretion, but there might be limitations in increasing the mediator levels, because of the feedback mechanisms in vivo. In addition, the analysis of crevicular fluid is a useful method for assessing cellular response to orthodontic force in vivo.

Distribution of Interleukin-1β+3954and IL-1α–889Genetic Variations in a Thai Population Group

BACKGROUND

The severe form of chronic periodontitis (CP) has been reported to be strongly associated with the presence of allele 2 of composite IL-1beta(+3954) and IL-1alpha(-889) genetic polymorphisms (genotype positive). However, other studies have reported conflicting findings, not only on the association between the composite IL-1 gene polymorphisms and CP, but also the link between IL-1 gene polymorphisms and aggressive periodontitis (AgP). These might have resulted from differences in ethnic background and disease entities. The aim of this study was to determine the distribution of IL-1beta(+3954) and IL-1alpha(-889) genetic polymorphisms in a group of Thai subjects based on their periodontal status, including CP, AgP, and healthy groups.

METHODS

A total of 123 Thai subjects were clinically and radiographically assessed for their periodontal status. Blood samples were collected by fingerstick and adsorbed onto filter paper. The IL-1beta(+3954) and IL-1alpha(-889) genotypes were performed by polymerase chain reaction, digested with restriction enzymes, and separated by gel electrophoresis.

RESULTS

The distribution of allele 1 homozygous genotype was 97.6% and 84.6% for IL-1beta(+3954) and IL-1alpha(-889), respectively. No allele 2 homozygous genotype was detected in either of these two gene loci. Only 1.6% (2 out of 123) of the subjects were genotype positive, which was too low to determine the association between the composite genotype of IL-1beta(+3954) and IL-1alpha(-889) and severe forms of periodontal disease.

CONCLUSION

Genetic polymorphism of IL-1 genes in these two loci may not be useful in predicting the severity of periodontal disease in the Thai ethnic group.

The role of acquired immunity and periodontal disease progression

Our understanding of the pathogenesis in human periodontal diseases is limited by the lack of specific and sensitive tools or models to study the complex microbial challenges and their interactions with the host's immune system. Recent advances in cellular and molecular biology research have demonstrated the importance of the acquired immune system not only in fighting the virulent periodontal pathogens but also in protecting the host from developing further devastating conditions in periodontal infections. The use of genetic knockout and immunodeficient mouse strains has shown that the acquired immune response-in particular, CD4+ T-cells-plays a pivotal role in controlling the ongoing infection, the immune/inflammatory responses, and the subsequent host's tissue destruction. In particular, studies of the pathogen-specific CD4+ T-cell-mediated immunity have clarified the roles of: (i) the relative diverse immune repertoire involved in periodontal pathogenesis, (ii) the contribution of pathogen-associated Th1-Th2 cytokine expressions in periodontal disease progression, and (iii) micro-organism-triggered periodontal CD4+ T-cell-mediated osteoclastogenic factor, 'RANK-L', which is linked to the induction of alveolar bone destruction in situ. The present review will focus on some recent advances in the acquired immune responses involving B-cells, CD8+ T-cells, and CD4+ T-cells in the context of periodontal disease progression. New approaches will further facilitate our understanding of their underlying molecular mechanisms that may lead to the development of new treatment modalities for periodontal diseases and their associated complications.

Analysis of multiple 2x2 tables with site-specific periodontal data

Periodontal data typically consist of observations made at multiple sites within each patient. Observations within a patient tend to be positively correlated; hence, standard statistical techniques that assume independence are invalid. Regression techniques for correlated data have been proposed; communicating results from these models, however, is difficult, due to their inherent complexity. Simpler statistical approaches have also been proposed, but many of these methods can be applied only when covariates are specific to the subject, and do not vary from site to site within a subject. In this paper, we present two methods for the analysis of multiple 2x2 tables containing site-specific periodontal data. The methods presented are modifications of the well-known Mantel-Haenszel methods. We illustrate these methods using a subset of data from a clinical trial examining the effects of scaling and root planing on levels of interleukin-1 beta.

The overexpression of cyclo-oxygenase-2 in chronic periodontitis

BACKGROUND

The objective of this prospective cross-sectional study was to determine if cyclo-oxygenase-2, or COX-2, is overexpressed in the inflamed gingival tissue of patients diagnosed as having moderate-to-severe chronic periodontitis, or CP.

METHODS

The authors evaluated clinical measures, crevicular fluid and gingival biopsy specimens from patients with moderate or severe CP (n = 16) and from healthy volunteers (n = 8). Patients were diagnosed as having CP based on clinical attachment loss, or CAL, of at least 5 millimeters at two sites in each quadrant and on evidence of alveolar bone loss as assessed from standard periapical or bite-wing radiographs. Healthy patients exhibited no sites with CAL of more than 2 mm and no evidence of alveolar bone loss. The authors used standard techniques to perform biochemical measures.

RESULTS

Levels of interleukin-1 beta, or IL-1beta, in crevicular fluid were more than doubled in the CP group (P < .05). The amounts of COX-2 mRNA and protein also were elevated in gingival tissues from subjects with CP compared with those from healthy subjects. To gain further mechanistic insights, the authors conducted in vitro studies. The results showed that lipopolysaccharide and tumor necrosis factor alpha, or TNF-alpha, induced COX-2 in macrophages, while IL-1beta and TNF-alpha induced COX-2 in oral epithelial cells.

CONCLUSIONS

Taken together, these results suggest that levels of COX-2 in gingivae reflect clinical measures of periodontitis and gingival inflammation.

CLINICAL IMPLICATIONS

The discovery of increased levels of COX-2 in inflamed gingival tissue suggests that COX-2 represents a pharmacological target for the prevention or treatment of CP.