Neutrophil Elastase and its Inhibitors in Human Gingival Crevicular Fluid during Experimental Gingivitis

The relative concentrations and absolute amounts of neutrophil elastase and its two inhibitors, α2-macroglobulin (α2-M) and alantitrypsin (α1-AT), were determined in gingival crevicular fluid (GCF) collected from six dental students who refrained from brushing the upper left or right quadrant during three weeks. Plaque and gingival indices and flow of GCF were measured before, during, and after the three weeks of no brushing. Functional elastase, representing the enzyme complexed with a2-M, was measured by use of a low-molecular-weight fluorogenic substrate. Elastolytic activity in GCF was also assayed by use of elastin as substrate. Antigenic elastase, representing the enzyme complexed with a 1-AT, as well as the inhibitors a2-M and al-AT were measured by ELISA. After three weeks of plaque accumulation, the concentrations of both functional and antigenic elastase increased by a factor of about 3, whereas the concentrations of the inhibitors increased in a much higher proportion. No free elastase could be detected in GCF, as evidenced by the Sephadex G-75 elution profile of GCF, by the negative results obtained when elastin was used as substrate, and by the demonstration that pure enzyme kept its activity against the low-molecular-weight substrate after being saturated by a2-M.

Association of thalassemia major and gingival inflammation: A pilot study

OBJECTIVES

This cross-sectional study aimed to investigate the relationship between thalassemia major (TM) and gingival inflammation through the salivary, serum, and gingival crevicular fluid (GCF) levels of matrix metalloproteinase (MMP)-8, MMP-9 and tissue inhibitor of MMP (TIMP)-1.

METHODS

Biofluid samples and full-mouth clinical periodontal recordings were obtained from 29 otherwise healthy patients with TM and 25 systemically healthy (SH) individuals. Biofluid samples were evaluated by immunofluorometric assay (IFMA) and enzyme-linked immunoassays (ELISAs). Data were tested statistically by Kolmogorov Simirnov, Mann-Whitney U tests, Spearman correlation analysis.

RESULTS

Age, smoking status, bleeding on probing, plaque index were similar in the study groups, but probing depth, gender data exhibited significant differences (p=0.037 for both). Salivary MMP-8, MMP-9, TIMP-1 concentrations were significantly higher in the TM than SH group (p=0.014; p<0.001; p=0.042, respectively). Serum TIMP-1 concentrations were significantly higher; MMP-8/TIMP-1, MMP-9/TIMP-1 molar ratios were significantly lower in the TM than SH group (p<0.001; p=0.005; p=0.022, respectively). Very few GCF samples revealed biochemical data above the detection limits. Numerous correlations were found between clinical periodontal parameters and biochemical data.

CONCLUSIONS

It may be suggested that TM may exacerbate the local inflammatory response as manifested in salivary MMP-8, MMP-9, TIMP-1 levels.

[Granulocyte elastase levels in saliva and gingival crevicular fluid of subjects with various periodontal conditions]

OBJECTIVE

To compare the granulocyte elastase (EA) levels in saliva and/or gingival crevicular fluid (GCF) of subjects with various periodontal conditions and analyze the relation between EA levels in GCF and in saliva.

METHODS

GCF and salivary samples were collected from 17 subjects with healthy periodontium, 14 with gingivitis, 24 with chronic periodontitis (CP) and 24 with aggressive periodontitis (AgP). The EA levels in GCF and saliva were analyzed.

RESULTS

The GCF-EA level in AgP were significantly higher than that in CP (0.485 3 ± 0.225 0 vs. 0.288 4 ± 0.193 1, P<0.01); the levels of EA in saliva of periodontitis patients (AgP and CP) were higher than those of healthy and gingivitis subjects (0.844 5 ± 0.660 6, 0.637 3 ± 0.648 9 vs. 0.031 6 ± 0.020 6, 0.012 2 ± 0.005 8, P<0.001). A positive correlation was found between EA levels in saliva and those in GCF (r=0.660).

CONCLUSION

GCF-EA level may serve as a marker for clinical assessment of periodontal conditions. The measurement of EA levels in saliva may facilitate to overall screen periodontitis patients in epidemiological study or to monitor periodontal conditions in clinical practice.

Localized reduction of gingival inflammation using site-specific therapy with a topical gingival patch

METHODS

Sites of inflammation were identified on subjects with moderate-to-severe chronic periodontitis, and were allocated to either patch placement or untreated controls, both for 24 hours. Conventional treatment with scaling and root planing was postponed during the study period. Inflammation was evaluated measuring neutrophilic activity using gingival crevicular fluid (GCF) beta-glucuronidase (b-glu) levels, and clinical response was evaluated using the gingival index (GI).

RESULTS

A total of 26 patients were recruited and 36 sites examined, with 22 sites on which the patch was placed and 14 controls. GCF b-glu levels at 24 hours were reduced following patch placement, significantly more so than with controls (17/22 vs. 3/14 sites, respectively; p = 0.002). The patch placement resulted in a significant reduction in mean b-glu levels (-2.52 +/- 1.62), with a reduction from baseline of 29.7%. This compared to untreated controls, for whom the mean b-glu levels and percent change from baseline increased (2.14 +/- 0.89 and 33%, respectively). At 24 hours, GI response rate for treated sites was better than for control sites (18/21 vs. 7/14; p = 0.053). No adverse events were reported in either group.

CONCLUSION

This pilot study indicates that a topical gingival patch promotes reduction of gingival inflammation. Further clinical testing of this novel treatment of gingival inflammation is warranted.

Analysis of cathepsin-K levels in biologic fluids from healthy or diseased natural teeth and dental implants

PURPOSE

Cathepsin-K is an enzyme involved in bone metabolism. This feature may make it important both for natural teeth and dental implants. The aims of the present study were to comparatively analyze cathepsin-K levels in gingival crevicular fluid (GCF) and peri-implant sulcus fluid (PISF) and to determine whether GCF and PISF cathepsin-K profiles reflect the clinical periodontal/peri-implant status.

MATERIALS AND METHODS

Clinical parameters (probing depth, Gingival Index, Plaque Index, and bleeding on probing) were recorded, and GCF/PISF samples were obtained from natural teeth (group T) and dental implants (group I), which were divided into groups based on health (clinically healthy, gingivitis/peri-implant mucositis, and periodontitis/peri-implantitis). Cathepsin-K activity was determined with a commercially available cathepsin-K activity assay kit (BioVision).

RESULTS

Sixty natural teeth and 68 dental implants were examined. Teeth with periodontitis (group T-3) showed significantly higher total cathepsin-K activity (10.39 units) than teeth with gingivitis (group T-2, 1.71 units) and healthy teeth (group T-1, 1.90 units). The difference in cathepsin-K activity between groups T-2 and T-1 was not significant. Implants with peri-implantitis (group I-3) had higher total enzyme activity (10.26 units) than healthy implants (group I-1) (3.44 units). Although the difference between clinical parameters was not significant, group I-3 had higher cathepsin-K levels than group I-2 (4.74 units). When natural teeth (T-1, T-2, T-3) were compared to implants (I-1, I-2, I-3), no significant differences were observed for cathepsin-K levels.

CONCLUSION

More cathepsin-K activity was clearly observed with inflammatory periodontal and peri-implant destruction. The highest cathepsin-K levels detected in GCF and PISF samples, obtained from sites with periodontitis and peri-implantitis, suggests the potential involvement of cathespin-K in increased bone metabolism around natural teeth and dental implants.

The effect of Parodontax® on the MMP-8 concentration in gingivitis patients

The aim of the study was to evaluate the efficacy of Parodontax® (GlaxoSmith-Kline, Bühl, Germany) on the signs gingival inflammation and the enzyme activity of matrix metalloproteinase-8 (aMMP-8) in the gingival crevicular fluid. After approval by the ethics commission, a total of 50 volunteers participated in the study; group 1 (n = 25, age: 43 ± 12 years) with moderate gingivitis (BOP +) and group 2 (n = 25, age: 29 ± 11 years) with clinically healthy gingival conditions (BOP -). After obtaining anamnestic data, the dental examination included assessment of oral hygiene (Quigley & Hein 1962), gingival inflammation (Saxer & Mühlemann 1975), probing pocket depth and clinical attachment level. Gingival crevicular fluid was collected from both groups. A quantitative assessment of aMMP-8 in the gingival crevicular fluid samples was performed (DentoAnalyzer, Dentognostics GmbH, Jena, Germany). Study participants were instructed to use only Parodontax®. After three weeks, all parameters were measured again. The aMMP-8 values of group 1 were significantly reduced after the use of Parodontax® toothpaste and mouthwash (p < 0.001; baseline median 41.25 ± 38.16 ng/ml, final post-treatment median 7.73 ± 7.58 ng/ml aMMP-8 eluate; group 2: baseline median 3.75 ± 3.16 ng/ml, final post-treatment median 3.73 ± 1.54 ng/ml aMMP-8 eluate). Gingival inflammation and plaque accumulation were reduced. It was shown that Parodontax® was effective in reducing the enzymatic activity of inflammation.

Lysozyme and microbiota in relation to gingivitis and periodontitis

BACKGROUND

The aim of this study was to investigate associations between the immune component of the oral cavity, lysozyme, in gingival crevicular fluid and unstimulated saliva, and colonization dynamics of periodontopathogenic bacteria from supra- and subgingival plaque samples in patients with gingivitis or periodontitis.

MATERIAL/METHODS

Lysozyme in crevicular fluid and unstimulated saliva, and bacteria in supra- and subgingival plaque samples were assessed in 84 samples from 28 patients with gingivitis, 96 samples from 32 patients with periodontitis, and 72 samples from 24 donors with intact periodontium and free of internal disease. Lysozyme activity was determined spectrophotometrically. The micro-IDent plus assay was used to detect 6 periodontopathogenic bacteria plaque samples.

RESULTS

Lysozyme activity in crevicular fluid in the gingivitis and periodontitis groups was significantly greater than that in the donor group, but lysozyme activity in unstimulated saliva was less than that in the donor group. Peptostreptococcus micros, Fusobacterium periodontium and Campylobacter rectus were predominant in subgingival plaque samples in the periodontitis group compared to the donor group (P<0.001), and Eubacterium nodatum and Eikenella corrodens were predominant in the gingivitis group compared to the donor group (P<0.001).

CONCLUSIONS

Lysozyme activity in crevicular fluid and in unstimulated saliva correlated with periodontal pocket depth in donors and in patients with gingivitis or periodontitis (specificity and sensitivity were both 100%). These findings indicate that infection with P. micros, F. periodontium, E. nodatum, E. corrodens, and C. rectus may be an important indicator of inflammatory periodontal disease development.

Altered gene expression levels of matrix metalloproteinases and their inhibitors in periodontitis-affected gingival tissue

BACKGROUND

The balance between the degradation and synthesis of extracellular matrix determines periodontal attachment levels and alveolar bone matrix concentration in periodontal diseases. Matrix metalloproteinases (MMPs) are known to degrade periodontal ligamental attachment and bone matrix proteins. The purpose of this study was to examine the effect of different expression levels of MMPs and their inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), in periodontitis.

METHODS

Sixteen inflamed gingival tissue samples from subjects with generalized chronic periodontitis and 14 control tissue samples from systemically and periodontally healthy subjects were evaluated. The total RNA was extracted, and the transcript levels for MMP-1, -3, -9, and -13 and TIMP-1, -2, -3, and -4 relative to beta-actin were determined by quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

Gene transcript levels for MMP-1 and TIMP-4 were significantly higher in periodontitis-affected gingival tissues (P <0.05). MMP-3, -9, and -13 and TIMP-1 mRNAs also were elevated in periodontitis; however, the difference was not statistically significant. TIMP-2 and -3 mRNA levels were similar in healthy and diseased gingivae. The ratios of MMP-1/TIMP-2 (P <0.01), MMP-3/TIMP-2 (P <0.05), MMP-9/TIMP-2 (P <0.05), and MMP-1/TIMP-3 (P <0.01) from periodontitis lesions were significantly higher than those in the control tissues.

CONCLUSIONS

Upregulated MMP expression and an increased MMP/TIMP ratio indicate that a potential imbalance between degradation and synthesis of extracellular matrix persists in periodontitis-affected gingival tissues. This process may be responsible for increased tissue breakdown in periodontitis.

The effect of age on prostaglandin-synthesizing enzymes in the development of gingivitis

BACKGROUND AND OBJECTIVE

The aim of this study was to identify the expression of cyclooxygenase-1, cyclooxygenase-2, cyclooxygenase-3, and microsomal prostaglandin E synthase-1 in young and elderly subjects.

MATERIAL AND METHODS

Periodontally healthy subjects were divided into young (18-30 years, n = 7) and elderly (46-77 years, n = 7). A gingival biopsy was taken at baseline. After experimental gingivitis, clinical examination was repeated and a second biopsy was taken. The expression of cyclooxygenase-1, cyclooxygenase-2, cyclooxygenase-3, and microsomal prostaglandin E synthase-1 was analyzed by means of immunohistochemistry.

RESULTS

In both healthy age groups, cyclooxygenase-1 and microsomal prostaglandin E synthase-1 were expressed in epithelial cells, endothelial cells and fibroblast-like connective tissue cells. Cyclooxygenase-1 was found in Langerhans' cells of the epithelium. Cyclooxygenase-2 expression was observed in cells exhibiting the morphology of epithelial mitosis cells, and the expression of cyclooxygenase-2 in periodontally healthy elderly subjects was significantly lower (p < or = 0.05). Following experimental gingivitis, cyclooxygenase-1 and microsomal prostaglandin E synthase-1 expression did not change. However, the expression of cyclooxygenase-2 was significantly increased in both age groups (p < or = 0.05). Cyclooxygenase-3 was not detected in any group investigated.

CONCLUSION

Cyclooxygenase-1 and microsomal prostaglandin E synthase-1 were expressed constitutively in gingival tissue, and expression was unaffected by age or inflammation states. In contrast, the expression of cyclooxygenase-2 was weaker in elderly subjects. In the course of experimental gingivitis, cyclooxygenase-2 was induced in both age groups.

Expression of peroxiredoxin I in plasma cells of oral inflammatory diseases

The participation of reactive oxygen species (ROS) in the immune response, both as pathogen killers and as mediators of signaling pathways, is well established. However, little is known about the enzymes responsible for ROS elimination in immune cells. Peroxiredoxin I (PrdxI) is a multifunctional enzyme that exhibits thioredoxin-dependent peroxidase activity. It has been described as a major hydrogen peroxide (H(2)O(2))-inducible protein in mouse peritoneal macrophages. In order to characterize its participation in the antioxidant defense of inflammatory/immune cells in greater detail, we evaluated its expression at sites of the oral cavity affected by inflammatory disorders induced by different agents (infectious, chemical, mechanical or tumor). In this study we demonstrated, by immunohistochemistry, that PrdxI is expressed in plasma cells, but not in B lymphocytes, regardless of the inflammation-inducing agent. We suggest that PrdxI induction could be considered a crucial part of the cellular adaptive response to the B-cell differentiation process to cope with the additional H(2)O(2) associated with massive disulfide bond formation during immunoglobulin folding in the endoplasmic reticulum of plasma cells. PrdxI could diminish the tissue damage that accompanies inflammation.

Levels of metalloproteinase-2 and -9 and tissue inhibitor of matrix metalloproteinase-1 in gingival crevicular fluid of patients with periodontitis, gingivitis, and healthy gingiva

OBJECTIVE

To compare the levels of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in patients with gingivitis and periodontitis and in healthy controls.

METHODS

Levels of MMP-2, MMP-9, and TIMP-1 were determined by ELISA in patients with healthy gingiva (n = 16), gingivitis (n = 18), and periodontitis (n = 25). The subjects with periodontitis were examined before and 1 month after basic periodontal therapy.

RESULTS

Slightly higher concentrations of MMP-9 were observed in patients with periodontitis but without statistical significance. MMP-2 was found to be slightly diminished in these patients. The lowest concentrations of MMP inhibitor (TIMP-1) were observed in patients with periodontitis, in whom the concentrations increased after periodontal treatment.

CONCLUSION

The reduction in TIMP-1 concentrations in disease situations suggests a breakdown of the balance between the amount of MMPs and their inhibitor.

[Clinical association of gingipain K-caspase like subdomain expression of Porphyromonas gingivalis with puberty gingivitis]

OBJECTIVE

To detect and compare the activity and intensity of gingipain K (Kgp)-caspase like subdomain in culture medium and cell extract of Porphyromonas gingivalis (Pg) isolates in puberty gingivitis and to reveal the possible association of Kgp with puberty gingivitis.

METHODS

Thirty-six children of 14 to 17 years old were enrolled in this study. Clinical parameters including gingival index (GI), sulcus bleeding index (SBI) and probing depth (PD) were evaluated. Subgingival plaque samples were collected and Pg isolates were obtained. 16S rRNA PCR was used to confirm Pg clinical isolates. Bacteria were grown in batches of BHI base and harvested at the end of log-phase growth. Culture fractions (culture medium and cell extract) of 10 Pg isolates were performed with SDS-PAGE and Western blot technique using primary antibody against specific Kgp-caspase like subdomain. Activity of Kgp in both samples was detected as well. The data were statistically analyzed using SPSS 11.5 software. The relationship between the Kgp intensity/activity of Kgp and the clinical parameters was statistically analyzed using Spearman correlation coefficient.

RESULTS

There was positive correlation between the intensity/activity of Kgp and the clinical parameters (P < 0.05).

CONCLUSIONS

The Kgp in clinical isolates of Pg from puberty gingivitis is in complicated forms. Caspase-like molecules with low molecular weight may exist as intracellular functional protein molecules which can affect the interaction between Pg and host. Kgp was contributes in certain degree to the pathogenesis of puberty gingivitis.

Gingival crevicular fluid matrix metalloproteinase-13 levels and molecular forms in various types of periodontal diseases

BACKGROUND

The purpose of this study was to evaluate the levels, molecular forms and activation degree of matrix metalloproteinase-13 (MMP-13) in the gingival crevicular fluid (GCF) of patients with periodontal diseases and to correlate these findings with periodontal clinical parameters.

METHODS

Sixty one subjects participated in this study as healthy (n = 18), gingivitis (n = 17), aggressive periodontitis (AgP; n = 15) and chronic periodontitis (CP; n = 11) groups. Clinical measurements and GCF samples were obtained from each subject. The molecular forms of MMP-13 in GCF samples were analyzed by Western immunoblotting method. Differences among the groups were assessed using non-parametric statistical analysis.

RESULTS

In the CP group, levels of 29-30 kDa fragment of MMP-13, total MMP-13, and activated form of MMP-13 were significantly higher than in the healthy, gingivitis and AgP groups. GCF levels of all molecular forms of MMP-13 in AgP group were similar to those of healthy and gingivitis groups. Total and activated MMP-13 levels were positively correlated with all clinical parameters. 29-30 kDa fragment levels of MMP-13 were also positively correlated with papillary bleeding index and plaque index.

CONCLUSION

These results indicate that elevated GCF MMP-13 levels may play an important role in the pathogenesis of CP. These data demonstrate, for the first time, pathologically activated and elevated MMP-13 in GCF.

Increased transglutaminase activity was associated with IL-6 release in cultured human gingival fibroblasts exposed to dental cast alloys

Molecular mechanisms underlying gingival and periodontal inflammation caused by dental alloys are still poorly understood. Recently, it has been demonstrated that tissue transglutaminase can be involved in inflammatory cell response. The aim of this study was to evaluate effects of exposure to orthodontic materials on transglutaminase in cultured human gingival fibroblasts. The incubation with Ni-Ti heat-activated (T3) or Ni-Ti super-elastic (T4), and with Ni-Cr-Co (T2) alloys produced respectively 2.5-fold and 8-fold increases in IL-6 release compared with control cultures. Transglutaminase activity was significantly increased in cells exposed to T3 and T4 alloys (about 170% of control; p < 0.05), where it was mainly localized close to inner part of cell membrane. The exposure to T3 and T4 specimens significantly up-regulated also tTG expression compared with control cultures. These data first show an association between IL-6 release and tissue transglutaminase increases, suggesting that TGase-mediated reactions may play a major role in periodontal inflammation.

Gingival Crevicular Fluid Matrix Metalloproteinase-25 and -26 Levels in Periodontal Disease

BACKGROUND

Tissue destruction associated with the progression of periodontal disease is caused by a cascade of host and microbial proteolytic enzymes. Host-derived matrix metalloproteinases (MMPs) play an important role in the degradation of the extracellular matrix. Leukolysin/membrane-type 6 (MT-6)/MMP-25, the latest member of the MT-MMP subgroup of the MMP family, is primarily expressed by neutrophils and involved in extracellular matrix turnover. Matrilysin-2/MMP-26 (endometase), a novel member of the matrilysin subgroup of the MMP family, can degrade the extracellular matrix, alpha1-antitrypsin, and activate pro-MMP-9. Our study aimed to examine the levels, molecular forms, and degrees of activation of MMP-25 and MMP-26 in gingival crevicular fluid (GCF) from patients with different periodontal diseases.

METHODS

A total of 105 subjects, 35 with generalized aggressive periodontitis (GAgP), 29 with chronic periodontitis (CP), 20 with gingivitis, and 21 periodontally healthy subjects, were included in this study. Periodontal status was evaluated by measuring probing depth, clinical attachment loss, presence of bleeding on probing, and plaque. GCF MMP-25 and MMP-26 levels were analyzed by computer-quantitated Western immunoblotting using specific antibodies.

RESULTS

The 57-kDa soluble pro-MMP-25 and 45- to 47-kDa active form of MMP-25 were detected by Western immunoblots in CP and GAgP GCF, and lesser levels of these soluble MMP-25 immunoreactive bands were detected in gingivitis GCF. An enhanced and similar degree of MMP-25 activation was found in GAgP, CP, and gingivitis groups. There were no detectable MMP-25 immunoreactivities in the healthy subjects' GCF. GAgP and CP groups had elevated GCF MMP-26 levels and degrees of activation compared to the gingivitis and healthy groups (P <0.008). The gingivitis group had higher GCF MMP-26 levels and degree of activation compared to the healthy group (P <0.008).

CONCLUSIONS

The present study demonstrated the presence of soluble or shed forms of MMP-25 and MMP-26 in GCF of patients with different periodontal diseases. Increased levels and activation of MMP-25 and MMP-26 in GCF are associated with an enhanced severity of periodontal inflammation, suggesting that these novel MMPs can participate in the progression of periodontal diseases. They may prove to be diagnostically useful and could be targets of medication in the future.

Inhibition of Experimental Gingivitis in Beagle Dogs With Topical Mercaptoalkylguanidines

BACKGROUND

Nitric oxide is a free radical produced in host tissues by constitutive and inducible forms of the enzyme nitric oxide synthase. Nitric oxide plays physiological roles, but it is also involved in the pathophysiology of several inflammatory conditions, including arthritis, ulcerative colitis, and circulatory shock. Local increases in inducible nitric oxide synthase (iNOS) and reactive nitrogen products have also been demonstrated in humans and animals with periodontal disease. This masked, randomized, placebo-controlled preclinical investigation examined the effect of two mercaptoalkylguanidines, mercaptoethylguanidine (MEG) and guanidinoethyldisulfide (GED), which are iNOS inhibitors and reactive nitrogen scavenging compounds, on the development of experimental gingivitis in beagle dogs.

METHODS

Fifteen female, 1-year-old beagles first completed a 2-week dose-escalation experiment during which a maximum tolerated dose was determined for MEG and GED gels. Thereafter, all animals were brought to optimal gingival health by mechanical scaling, followed by rigorous daily toothbrushing over a 4-week washout period. Experimental gingivitis was then induced, with cessation of plaque control and institution of a soft diet over 8 weeks. Beagles randomly received 0.3% MEG, 0.3% GED, or placebo (vehicle) gels, topically applied twice daily to premolar teeth. Gingival inflammation, bleeding tendency, and supragingival plaque were clinically measured at baseline and at 2, 3, 4, 6, and 8 weeks. Comparisons among groups and between group pairs (active versus placebo) were made using Kruskal-Wallis tests.

RESULTS

From baseline to day 7, all groups expressed similar indices. Thereafter, significant and time-dependent increases in the plaque index (PI), gingival index (GI), and percentage of bleeding on probing (%BOP) were observed in placebo-treated beagles. Mean GI scores for beagles treated with GED or MEG gels remained at or below baseline levels for the entire treatment period. At weeks 2, 3, 4, and 8, GI scores were significantly lower for MEG and GED groups compared to the placebo group (P<0.05). In addition, MEG and GED gels significantly reduced gingival bleeding responses by 8 weeks (P<0.05). Although placebo-treated beagles demonstrated %BOP scores of 43% at week 8, GED- and MEG-treated beagles exhibited %BOP scores of 21% and 26%, respectively. Since no statistical difference among PI scores was noted for any of the time points, neither mercaptoalkylguanidine appeared to affect supragingival plaque levels.

CONCLUSION

The data from this preclinical study indicate that mercaptoalkylguanidines, topically administered, may significantly reduce experimental gingivitis in the beagle dog.

Relationship between gelatinases and bone turnover in the healing bone defect

PURPOSE

The aim of this pilot study was to determine the relationship between gelatinase (MMP-9 and MMP-2) markers of soft tissue inflammation/turnover at the bone/soft tissue interface and bone turnover (osteocalcin [OC], pyridinoline cross-linked carboxyl-terminal telopeptide of type 1 collagen [ICTP], and bone fill) during healing of an alveolar bone defect.

MATERIALS AND METHODS

Ten subjects undergoing oral surgery had a 5 x 5-mm trephine defect created on an edentulous ridge and were sampled at the bone/soft tissue interface at baseline (prior to flap reflection), 2 weeks and 12 weeks postsurgery, using a novel bone wash device. Recovered irrigants were analyzed for MMP-9 and MMP-2 by gelatin zymography, OC and ICTP with radioimmunoassays, and albumin (ALB; to normalize markers for blood content) with a sandwich enzyme-linked immunosorbent assay. Bone fill at 12 weeks was analyzed by radiographic absorptiometry.

RESULTS

All markers of enzymatic activity and bone turnover varied significantly across time (P < or = .03), with bone turnover markers OC and ICTP decreasing between baseline and 2 weeks, and MMP-9 and MMP-2 increased. Measures generally returned to near baseline levels after 12 weeks. MMP-9 versus MMP-2 (r = 0.97, P < .0001) and OC versus ICTP (r = 0.38, P = .048) were correlated with each other, while MMP-9 and MMP-2 were negatively correlated with ICTP (r = -0.48, P = .011 and r = -0.62, P = .006, respectively). MMP-9 was negatively correlated with subsequent bone fill (r = -0.63, P = .07).

CONCLUSIONS

Bone wash sampling showed that gelatinase activity at 2 weeks following creation of an alveolar defect appeared to decrease bone turnover and eventual bone fill, suggesting benefits for anti-MMP therapy during wound healing.

Lupinus albus, a novel vegetable extract with metalloproteinase inhibitory properties: a potential periodontal therapy

BACKGROUND

In this study we examine the properties of a vegetable extract from seeds of Lupinus albus (LU 105). In previous works we demonstrated that LU 105 reduced the expression, by gingival fibroblasts, of both matrix metalloproteinase (MMP)-2 and MMP-9. We decided to study the impact of LU 105 on cell proliferation and morphology. Using organ culture media we also studied the MMP and tissue inhibitors of metalloproteinases (timp) expression AND THE cytokines secretion.

METHODS

Healthy and inflamed gingival biopsies were placed in appendage culture with or without LU 105. The organ culture media were analyzed using Western blottings (MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, MMP-13, TIMP-1, and TIMP-2) and gelatine zymography. A reverse transcription polymerase chain reaction (RT-PCR) was also performed on healthy and inflamed gingival biopsies, which were maintained in culture with or without LU 105 0.1%. Then, we decided to determine the amount of cytokines present in the organ culture media such as interleukin (IL)-1 beta, IL-4, IL-6, transforming growth factor (TGF)-beta, and tumor necrosis factor (TNF)-alpha.

RESULTS

When gingival biopsies derived from inflamed tissues were cultured with LU 105 0.1% in the culture media, the MMP and TIMP expression and activity decreased significantly when compared to cultures without LU 105. Moreover, we did not note any statistical difference in the cell proliferation compared with human gingival fibroblast cultures without LU 105. Furthermore, IL-1 beta, IL-6, TGF-beta, and TNF-alpha amounts in the culture media decreased significantly, whereas IL-4 increased significantly when LU 105 0.1% was added to the culture media.

CONCLUSION

LU 105, a novel metalloproteinase inhibitor with few consequences on cell proliferation and morphology, is a vegetable extract with potential clinical capacity.

Plasminogen activator system in smokers and non-smokers with and without periodontal disease

BACKGROUND

The present study assessed levels of plasminogen activator (PA) system proteins in gingival crevicular fluid (GCF) and serum of chronic gingivitis, chronic periodontitis patients and periodontally healthy subjects and evaluated how smoking influenced these levels.

METHODS

Twenty chronic gingivitis; 20 chronic periodontitis patients and 20 periodontally healthy volunteers were consecutively recruited according to the inclusion criteria so that exactly half of the subjects in each category were smokers. GCF samples from four sites together with serum samples were obtained from each subject. GCF levels of tissue type PA (t-PA), urokinase type PA (u-PA), PA inhibitor-1 (PAI-1) and PA inhibitor-2 (PAI-2) and serum concentrations of cotinine, u-PA and PAI-1 were analysed by enzyme-linked immunosorbent assay.

RESULTS

The only statistically significant difference between smokers and non-smokers was a lower GCF PAI-2 concentrations in healthy smokers compared with healthy non-smokers (p<0.01). Gingivitis and periodontitis patients had higher GCF concentrations of PAI-2 than healthy subjects (p<0.002 and p<0.02 respectively). The ratio of u-PA:PAI-1 and t-PA:PAI-1 were significantly higher in GCF of smokers with periodontitis compared with "healthy" smokers, whereas the ratio of t-PA:PAI-2 was significantly lower in smokers with periodontal disease (p<0.05).

CONCLUSIONS

GCF levels of the PA system proteins are increased in chronic gingivitis and periodontitis compared with healthy gingiva. Smoking had only subtle effects on the GCF PA system proteins with the exception of PAI-2, and the balance of activators and inhibitors. These findings suggest one mechanism whereby smoking may exert detrimental effects on the periodontal tissues.

Secretory function of neutrophilic leukocytes of the patients with periodontal diseases

Aim of study was to examine periodontal status among 20 44 year old patients and to study the secretory function of peripheral venous blood neutrophilic leukocytes (NL) exposed to various antigens and alkaline phosphatase (AP) activity in gingival crevicular fluid (GCF) in patients suffering from gingivitis and periodontitis. Clinically were determined Russell's periodontal index (PI). Secretory function of NL affected by opsonized zymosane, non-opsonized E. coli was examined in 77 patients with gingivitis and periodontitis, and in 35 donors, free of internal diseases, by means of beta-glucuronidase (beta-GD), lysozyme (LZ). NL secreted higher levels of beta-GD in incubation medium in patients with periodontitis (p < or = 0.001) subject to degree of periodontal lesion. NL affected by various antigens secreted higher levels of LZ into non-cellular matrix in patients with gingivitis and periodontitis comparing to control environment in analogous groups. Data obtained from this study suggest that in patients with periodontitis response of NL to bacterial stimuli is specific and subject to the degree of periodontal lesion. Our study showed a significant difference of AP activity in GCF subject to pocket depth and degree of periodontal lesion. Once NL are exposed to corpuscules prone to phagocytosis, an increase in secretion of beta-GD and LZ can be explained by overall increase in secretion of NL lysosomic enzymes, thus disclosing the mechanism of inflammatory periodontal tissue damage.

Correlation of peri-implant health and myeloperoxidase levels: a cross-sectional clinical study

OBJECTIVES

At present, there are no diagnostic tools that permit early detection of peri-implantitis. The purpose of this cross-sectional study was to evaluate the correlation of myeloperoxidase (MPO) levels with traditional periodontal clinical parameters around dental implants including peri-implant pocket probing depth (PPD), gingival index (GI) and bleeding on probing (BOP), since MPO has been associated with destruction of periodontal tissues.

MATERIAL AND METHODS

Twenty-four healthy adult volunteers (9 men and 15 women) with 64 Ankylos Biofunctional implants (DentsplyFriadent, Mannheim, Germany) were recruited from Tallinn Dental Clinic. Biochemical and clinical parameters evaluated were the following ones: the level of MPO in the peri-implant sulcus fluid (PISF) (an analog for gingival crevicular fluid in natural teeth), PPD (mm), GI (0,1,2 or 3), and BOP (0 or 1).

RESULTS AND CONCLUSION

In comparison to the clinically healthy implants, total amounts of MPO were significantly higher in PISF collected around implants with inflammatory lesions. In addition, the levels of MPO were correlated with the clinical parameters. The results confirm the similarity of the inflammatory response of tissues surrounding implants and natural teeth, and suggest that MPO could be promising marker of inflammation around dental implants.

The short-term effectiveness of non-surgical treatment in reducing protease activity in gingival crevicular fluid from chronic periodontitis patients

OBJECTIVES

The aim of this study was to evaluate the short-term effect of non-surgical periodontal treatment on protease activity in gingival crevicular fluid (GCF) of patients with chronic periodontitis.

MATERIAL AND METHODS

After clinical examination, in which pocket probing depth, probing attachment level, plaque and bleeding indices were recorded, gingival fluid samples from 21 chronic periodontitis patients were collected from gingivitis (GP) and periodontitis (PP) sites with an intracrevicular washing method. Samples were taken in the same way from a group of patients with gingivitis alone (GG). The periodontitis patients received non-surgical periodontal treatment and were re-evaluated 30 days later. We compared elastase and collagenase activities before and after treatment. The former activity was measured with a low-weight substrate (S-2484) and inhibited by alpha-1-antitrypsin. Matrix-metalloproteinase-8 (MMP-8) was measured with an ELISA and collagenolytic activity with fluorescein-conjugated collagen type I as substrate.

RESULTS

All clinical parameters showed a significant improvement after treatment (p<0.05) which was accompanied by a significant reduction in the values of total elastase activity, free elastase, MPP-8 and collagenolytic activity in both GP and PP sites (p<0.05). However, the latter sites continued to have higher levels of MMP-8 and collagenolytic activity than the former ones after treatment. The free elastase activity and the proportion of free elastase in GP and PP samples after treatment remained higher than in untreated GG samples.

CONCLUSION

This study shows that the clinical improvements after non-surgical treatment are accompanied by reductions in protease and neutrophil activities.

Induction of CD13 on T-lymphocytes by adhesive interaction with gingival fibroblasts

Lymphocytes in peripheral blood do not express CD13 (aminopeptidase N), a membrane alanyl metallopeptidase. However, it has been demonstrated that locally infiltrated lymphocytes in chronic inflammatory sites can be CD13-positive, and possible involvement of stromal cell adherence in the induction of CD13 has been suggested. In this study, we examined whether T-lymphocyte/gingival-fibroblast interaction can activate T-lymphocytes to express CD13. CD13 expression was induced on PMA-activated T-lymphocytes only when they adhered directly to human gingival fibroblasts (HGF) at 2 hrs after the co-culture began, while an increase in the enzyme activity of CD13 was also confirmed in activated T-lymphocytes that had been co-cultured with HGF. Furthermore, CD13-positive T-lymphocytes were detected in inflamed gingival tissues in vivo. Analysis of these results indicates that direct interaction with HGF is essential for the induction of CD13 expression on T-lymphocytes that was also observed in periodontitis lesions.

Salivary cystatin activity and cystatin C in experimental gingivitis in non-smokers

BACKGROUND

Subjects with natural gingivitis and periodontitis have elevated levels of salivary cystatins compared to periodontally healthy individuals. Experimental gingivitis studies, however, have yielded conflicting results.

AIM

The present study investigated whether experimentally induced gingivitis is associated with changes in salivary cystatin levels.

MATERIAL & METHODS

Plaque scores, bleeding indexes and whole saliva samples of 35 non-smoking young adults were collected at the start and at the end of an experimental gingivitis trial, and 3 weeks after resuming oral hygiene. The saliva samples were assayed for protein concentrations, cystatin activity and cystatin C concentration.

RESULTS

During experimental gingivitis, plaque and bleeding scores increased significantly in all subjects and subsequently decreased significantly after reinstalment of oral hygiene procedures. No significant changes were observed for the protein concentration, cystatin activity and cystatin C concentration. No significant relation could be established between these salivary parameters and bleeding on marginal probing.

CONCLUSION

The present study confirms earlier results from Lie et al. (2001) that no significant changes occur in salivary cystatin activity and cystatin C concentration during and after experimental gingivitis.

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.

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.

Expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in healthy and diseased human gingiva

BACKGROUND

The purpose of this study was to quantify the amount of matrix metalloproteinases such as MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, and MMP-13 and tissue inhibitors of metalloproteinases TIMP-1 and TIMP-2 expressed by human gingival explants in culture media and the area fraction (AA%) of gingival collagen fibers according to the degree of inflammation, to investigate a possible correlation between these enzymes and collagen loss.

METHODS

Gingival tissue specimens from 6 healthy controls (group 1), 17 patients with mild gingival inflammation (group 2), 10 patients with moderate gingival inflammation (group 3), and 9 patients with severe gingival inflammation (group 4) were placed in organ culture for 3 days. The MMPs and TIMPs in the culture media were quantified using zymography, dot blotting, and Western blotting. Paraffin gingival sections were stained with sirius red F3Ba for visualization of collagen fibers, then the area fraction (AA%) occupied by the gingival fibers was determined by automated image analysis.

RESULTS

The AA% occupied by collagen fibers significantly decreased from group 1 (53%) to group 4 (35%). The decrease in collagen fibers was inversely correlated with the significant increase in MMP-1, MMP-9, and MMP-13 (dot blotting analysis), with the increase of the active form of MMP-2, and with the active form and proform of MMP-9 (zymography analysis).

CONCLUSION

The present study showed that metalloproteinases, particularly MMP-2, MMP-9, MMP-1, and MMP-13, are involved in the gingival extracellular matrix degradation during periodontitis.

Granulocyte elastase activity in static and flow gingival crevicular fluid

OBJECTIVES

This study aimed to evaluate the volume of gingival crevicular fluid (GCF) and granulocyte elastase activity in static GCF (sGCF) and flow GCF (fGCF) from subjects with various periodontal conditions.

METHODS

Eleven periodontally healthy, 10 gingivitis and 12 periodontitis subjects were recruited and the sites investigated consisted of healthy sites from healthy subjects (HH); healthy (HG) and gingivitis sites (GG) from gingivitis subjects; and healthy (HP), gingivitis (GP) and periodontitis sites (PP) from periodontitis subjects. fGCF samples were collected either 1 min or 5 min following sGCF collection by paper strip technique. GCF volume was determined by Periotron 6000 and granulocyte elastase activity was assayed with a specific substrate [l-pyroglutamyl-l-prolyl-l-valine-p-nitroanilide(pGluProVal-pNA)].

RESULTS

At baseline, no significant differences existed in clinical and GCF parameters between the two matched sites for subsequent collection of fGCF samples either 1 min or 5 min after sGCF sampling in all subjects. The flow exudate in HG and HP sites quickly replenished to sGCF levels, while a delayed replenishment was found in HH sites, despite the similar sGCF volumes of these sites. The GCF volume and elastase levels in the fGCF at 1 min were higher in GP sites than in GG sites (P < 0.05). Overall, depletion of elastase levels in the fGCF at 1 min was observed in all subjects, whereas elastase levels in the fGCF at 5 min had replenished to sGCF levels in HP, GP, PP sites and GG sites, but had remained at a lower level in HH and HG sites. An overall positive correlation was found between sGCF and fGCF for GCF volume and elastase activity (P < 0.001); however, this correlation varied with GCF parameters and with site conditions of the subjects concerned.

CONCLUSIONS

This study shows that patterns of dynamic changes in GCF flow and elastase activity varied under different periodontal conditions. Assessment of both sGCF and fGCF may allow better insight into the dynamic change of the target components in GCF.

Phenytoin-mediated androgen metabolism in gingival fibroblasts. Effects of the antiandrogen finasteride and the alkaline phosphatase inhibitor levamisole

OBJECTIVES

This investigation attempts to identify the role of the alkaline phosphatase inhibitor levamisole (L) and the antiandrogen finasteride (F) on 5alpha-reductase activity in gingival fibroblasts, to elucidate mechanisms for phenytoin-induced gingival overgrowth.

MATERIAL AND METHODS

Human gingival fibroblasts were incubated with Eagle's MEM and 14C-testosterone/14C-4-androstenedione as substrates; effective concentrations of phenytoin (Ph), levamisole (L) and finasteride (F), alone and in combinations of (Ph + F) (Ph + L) were added to the incubate. After 24 h, the medium was analysed for steroid metabolites and quantified using a radioisotope scanner.

RESULTS

The metabolites isolated were 5alpha-dihydrotestosterone (DHT), 4-androstenedione (4-A) or testosterone (T) from each substrate. With 14C-T as substrate, Ph stimulated DHT synthesis by 1.7-fold, while F and L inhibited this activity by 1.8-fold and 34%, respectively (n = 6; P < 0.001). The combination of Ph + F reduced yields by 2.7-fold compared with Ph alone and Ph + L reduced DHT synthesis by 2.4-fold compared with Ph alone (n = 6; P < 0.001). When 14C-4-androstenedione was used as substrate, similar trends were identified.

CONCLUSION

These results suggest that the alkaline phosphatase inhibitor levamisole and the 5alpha-reductase inhibitor finasteride can substantially decrease the yields of DHT in fibroblasts, stimulated by phenytoin. This could be a potential target for reducing the gingival overgrowth caused by phenytoin.

Nitric oxide synthesis and severity of human periodontal disease

The expression of the inducible nitric oxide synthase enzyme (iNOS) is a response to an inflammatory stimulus and produces a large amount of nitric oxide (NO), which may act as a cytotoxic molecule against the invading microorganism and may be related to both harmful and beneficial effects to tissues.

OBJECTIVE AND MATERIAL AND METHODS

In order to further characterize the presence of NO in human periodontal disease, we undertook a quantitative study of iNOS positive cells in samples of clinically healthy gingival tissues, plaque-induced gingivitis and localized chronic periodontitis using immunohistochemistry.

RESULTS

A significant increase in the number of iNOS+ cells mm-2 was found in the samples of the gingivitis and periodontitis compared with those of the control. In all groups most of the polymorphonuclear cells showed intense immunoreactivity for iNOS independent of the disease stage, and the percentage of iNOS+ polymorphonuclear cells increased significantly in periodontal disease when compared with the control.

CONCLUSION

Our results indicate that iNOS increases in the presence of periodontal disease. In addition, our findings suggest that polymorphonuclear cells present an additional activation pathway in periodontal disease, expressing significant iNOS and probably representing an important source of NO in human periodontal disease that has not been previously reported.

Granulocyte elastase, matrix metalloproteinase-8 and prostaglandin E2 in gingival crevicular fluid in matched clinical sites in smokers and non-smokers with persistent periodontitis

BACKGROUND/AIMS

Smokers with persistent periodontitis may have granulocytes with impaired function. This study aimed to determine the levels of granulocyte elastase, matrix metalloproteinase-8 (MMP-8) and prostaglandin E2 (PGE2) in gingival crevicular fluid (GCF) in smokers and non-smokers with persistent periodontitis.

METHODS

We analyzed GCF from 70 matched sites in 29 periodontitis and 6 gingivitis sites in 34 subjects, 17 smokers, and 17 non-smokers. We also analyzed separately GCF from 28 of these subjects, 14 smokers and 14 non-smokers in 14 matched periodontitis sites. The following measurements were made: elastase complexed to alpha1-antitrypsin (EA-alpha1AT) and MMP-8 with ELISA, functional elastase with a chromogenic substrate, and PGE2 with radioimmunoassay (125I RIA). The significance of the findings was determined with Mann-Whitney test.

RESULTS

In the 29 matched periodontitis sites, smokers had significantly more functional elastase (p<0.005) and more EA-alpha1AT (p<0.05) than non-smokers. In the 14 matched periodontitis sites in 14 smokers and 14 non-smokers, the former had significantly more functional elastase than the latter (p<0.001). A significant correlation was found between EA-alpha1AT and MMP-8 in smokers (p<0.05) and non-smokers (p<0.001) and a positive correlation between levels of functional elastase and MMP-8 in non-smokers (r2=0.98; p<0.001).

CONCLUSIONS

Granulocyte function seems to be impaired in smokers with persistent periodontitis. The cells react to the bacterial challenge by releasing serine proteases, which reflect the degradation of connective tissue. The risk of progression of the disease is therefore higher in smokers with persistent periodontitis than in non-smokers.

Relation between alkaline phosphatase in gingigval crevicular fluid of implant teeth and the curing result

OBJECTIVE

To discover the relation between alkaline phosphatase (ALP) in gingival crevicular fluid (GCF) of implant teeth and the curing results.

METHODS

We measured the ALP level in GCF among 56 cases of implant teeth which included 2 failed cases, 5 cases with bad oral hygiene and gingivitis, and compared it with that in the normal group composed of 10 persons.

RESULTS

The ALP levels in normal group and success implant group showed no difference. The ALP levels in normal group and success with gingivitis group showed obvious difference. The ALP levels of the 2 failed cases are the highest of all.

CONCLUSIONS

The ALP level in GCF is an important index in evaluating the curing result of the implant teeth.

Concentration of interleukin-1beta and neutrophil elastase activity in gingival crevicular fluid during experimental gingivitis

BACKGROUND/AIM

The aim of the present study was to measure interleukin-1beta concentrations and neutrophil elastase activity in gingival crevicular fluid (GCF) during experimental gingivitis in humans.

MATERIAL AND METHODS

12 healthy young men participated. After prophylaxis, they performed optimal hygiene to reach plaque and gingivitis indices of or approaching zero. All oral hygiene measures were then ceased for a period of 18 days. The Quigley-Hein plaque index (PLI) and Saxer & Mühlemann papillary bleeding index (PBI) were assessed. GCF samples were taken from the mesiobuccal site of two contralateral teeth in the upper jaw by means of periopapers at baseline and on days 3, 7, 14 and 18. After measuring the gingival crevicular fluid volume (GCFV) with the Periotron 8000, the samples were analyzed in our laboratory for the detection of IL-1beta concentration by ELISA.

RESULTS

PLI and PBI showed a reduction prior to baseline reaching almost zero, both increasing from day 0 to day 18 (PLI=from 0.1 to 2.9, PBI=from 0 to 2.0). IL-1beta concentration increased from 229.25 ng/ml (day 0) to 526.13 ng/ml (day 18). Clinical data and IL-1beta concentrations were correlated with elastase activity (EA). No significant correlation could be demonstrated between the clinical parameters assessed and IL-1beta or EA (Spearman rank correlation coefficient). A correlation between GCFV and PBI from day 0 to day 18 could be demonstrated.

CONCLUSION

Overall, both IL-1beta and EA showed an increase from baseline throughout the whole study.

Neutral proteases in crevicular fluid as an indicator for periodontal treatment intervention

PURPOSE

To longitudinally determine if early therapeutic intervention, based on a positive neutral protease activity (NPA) assay score could effectively arrest the progress of periodontal disease destruction.

MATERIALS AND METHODS

63 periodontal sites which had previously undergone probing attachment loss were identified from among 31 previously treated adult periodontitis patients who were monitored during periodontal maintenance for an average of 3 yrs. Clinical levels of gingival inflammation and attachment levels and NPA assay data were collected at the beginning of each maintenance visit. When a site tested negative with the assay, routine Supportive Periodontal Therapy (SPT) was followed during the same appointment, while sites exhibiting a positive NPA score received more aggressive periodontal treatment.

RESULTS

During the study period, 51 of 63 sites displayed at least one positive NPA score. Our protocol of administering periodontal treatment rendered at the visit showing a positive NPA score revealed that only 1 of the 51 sites lost > or = 1 mm attachment during the study period. The remaining 50 positive assay sites showed an overall gain of > or = 1 mm of probing attachment over the course of the study. 12 of 63 sites consistently tested negative for neutral protease enzyme activity and remained stable, although 9 of these sites exhibited bleeding on probing (BOP) at least once during this study. Initial group mean probing attachment measurements were 5.6 mm for NPA negative and 5.7 mm for NPA positive sites.

Salivary cystatin activity and cystatin C in natural and experimental gingivitis in smokers and non-smokers

BACKGROUND

Recent studies show that subjects with natural gingivitis or periodontitis have elevated levels of salivary cystatins compared to periodontally healthy individuals. Increased glandular output of cystatins in inflammatory conditions suggests an active, most likely protective, rôle for these proteins in inflammatory processes. Furthermore, it has been shown that the development of gingival inflammation is suppressed in smokers during experimental gingivitis.

AIMS

The purpose of the present study was to investigate whether (i) the levels of salivary cystatins in natural gingivitis are related to smoking status, and (ii) to study whether experimentally induced gingivitis is associated with changes in salivary cystatin levels, in both smokers and non-smokers.

MATERIAL AND METHODS

Whole saliva samples were taken in relation to natural gingivitis, gingival health and 14-day experimental gingivitis in 25 non-dental students (14 non-smokers and 11 smokers). The salivary flowrate was determined. Samples were analyzed for levels of protein, cystatin and cystatin-C.

RESULTS

Salivary flow and protein concentrations in cleared human whole saliva samples of non-smokers and smokers were not different from each other at any timepoint during the trial. With regard to cystatins, the results showed that in the state of natural gingivitis cystatin activity is lower in smokers as compared to non-smokers. In smokers, the resolution of natural gingivitis to the state of gingival health did not result in a change of cystatin activity and levels of cystatin C. At the end of the 14-day experimental gingivitis period, smokers showed a decrease in cystatin activity and cystatin C as well as lower outputs of cystatin activity and cystatin C.

CONCLUSION

Smoking is associated with lower cystatin activity and output of cystatin C during gingival inflammation.

Human fibroblasts ubiquitously express glutamic acid decarboxylase 65 (GAD 65): possible effects of connective tissue inflammation on GAD antibody titer

BACKGROUND

Type 1 diabetes is caused by a destruction of pancreatic beta cells due to autoimmunity. Autoantibody against glutamic acid decarboxylase (GAD) 65 expressed in pancreatic beta cells is widely used as a predictive marker for pancreatic destruction. In this study, we hypothesized that if certain cells in periodontal tissues could express GAD, then it may influence GAD antibody titer.

METHODS

We used: 1) reverse transcription-polymerase chain reaction (PCR) analysis to detect GAD 65 mRNA in various cells; 2) nucleotide sequencing analysis to confirm that amplified PCR product is the gene encoding GAD; and 3) Western blotting to determine the expression of GAD 65 protein in human gingival fibroblasts. Immunohistochemical staining of GAD 65 protein in normal and inflamed gingiva was performed to examine the potential influence of periodontal inflammation on GAD 65 expression. GAD antibody titer in sera of periodontal patients as well as healthy subjects was measured to determine if periodontal patients could develop autoantibody against GAD 65.

RESULTS

Cultured human gingival, periodontal, and dermal fibroblasts and mesangial cells expressed GAD mRNA. Nucleotide sequencing analyses confirmed the amplified PCR product as GAD 65. Western immunoblotting analyses and immunohistochemical staining revealed that the GAD 65 protein was expressed in vitro and in vivo. The expression of GAD 65 in inflamed tissue was higher than that in normal tissues. Two of 62 periodontal patients without diabetes showed an increased antibody titer against GAD 65, while none of the systemically healthy subjects showed an increased antibody titer against this antigen.

CONCLUSIONS

We concluded that periodontal inflammation may result in higher levels of GAD and influence GAD antibody titer, and, hence, affect diabetic diagnosis based upon GAD antibody production.

Arg-gingipain is responsible for the degradation of cell adhesion molecules of human gingival fibroblasts and their death induced by Porphyromonas gingivalis

Arg-gingipain (Rgp) and Lys-gingipain (Kgp) are two major cysteine proteinases produced by the oral anaerobic bacterium Porphyromonas gingivalis, which has been shown to act as major pathogen in the development and progression of periodontal diseases. These enzymes are also important for this organism to proliferate and survive in periodontal pockets. Here we show that Rgp is responsible for the disruption of fibronectin-integrin interactions in human gingival fibroblasts by P. gingivalis. Fibroblasts incubated with the culture supernatant of P. gingivalis showed a time-dependent loss of the adhesion activity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting revealed that fibronectin and integrin subunits alpha2, beta1 and beta3 in the fibroblast culture largely disappeared with the treatment. The detached cells became committed to death by disruption of contacts between adhesion molecules. In contrast, the culture supernatants from the Rgp-deficient mutants produced no significant changes in either cell adhesion or viability. Prior treatment of the culture supernatant of P. gingivalis with an Rgp inhibitor, but not a Kgp inhibitor, strongly inhibited the detachment of fibroblasts followed by cell death. These results suggest that Rgp disrupts the integrin-fibronectin interactions in fibroblasts, thereby contributing to the damage of periodontal tissues in periodontal diseases caused by P. gingivalis.

Expression of cytokines and inducible nitric oxide synthase in inflamed gingival tissue

BACKGROUND

Periodontopathic bacteria induce inflammation of periodontal tissues. The cytokines and nitric oxide released in periodontal lesions have been reported to play a protective role in bacterial infection and to relate to the process of inflammation. To clarify the relationship between colonization of periodontopathic bacteria and cytokines, we evaluated profiles of inflammatory cytokines, chemokine, anti-inflammatory cytokines, and inducible nitric oxide synthase (iNOS) and colonization by Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans, which are major pathogens of periodontitis.

METHODS

mRNA expression of cytokines and iNOS in inflamed and healthy gingival tissue was determined using reverse transcription-polymerase chain reaction (RT-PCR), and the relationship between their profiles and the detection of specific bacteria was analyzed.

RESULTS

The relative expression of interleukin (IL)-6 and iNOS mRNAs in periodontal lesions was significantly higher than those in healthy individuals. IL-6 mRNA expression was also significantly higher at bleeding on probing (BOP)-positive sites than at BOP-negative sites. The expressions of IL-1alpha and IL-8 increased, but IL-10 expression decreased at sites where A. actinomycetemcomitans was detected. We found no correlation between the expression of cytokine and iNOS mRNA and infection by P. gingivalis.

CONCLUSIONS

The expression of IL-6 may reflect inflammation in gingival tissue, and iNOS may be involved in the inflammatory process in periodontitis. The presence of A. actinomycetemcomitans or P. gingivalis might relate to the different cytokine profiles of IL-1alpha, IL-8, and IL-10.

Cyclooxygenase-2 is upregulated in inflamed gingival tissues

BACKGROUND

Increased release of prostaglandins (PG) within periodontal tissues is considered to play a pathogenetic role during periodontal disease progression. The rate-limiting step in the formation of PG from arachidonic acid is catalyzed by cyclooxygenase (COX). Currently there are 2 known isoforms of the enzyme. COX-1 is constitutively expressed in various tissues whereas COX-2 is an inducible enzyme believed to be responsible for PG synthesis at sites of inflammation. The purpose of this study was to compare COX-2 expression in inflamed and healthy human gingiva and further explore some of the pathogenetic mechanisms which may lead to elevated COX-2 expression in vivo.

METHODS

Thirty-two gingival biopsies were obtained during routine oral surgical procedures and were processed histologically using hematoxylin and eosin to determine the degree of inflammation. Of these biopsies, 7 with low and 7 with high histological levels of inflammation were further processed immunohistochemically in order to assess the levels of COX-2 expression in situ. To explore some potential mechanisms of COX-2 upregulation, gingival connective tissue primary cell cultures were established and challenged with periodontal bacteria or proinflammatory cytokines in vitro. The levels of COX-2 expression were analyzed by Western blot of cell lysates. COX-2 activity was assessed by quantifying prostaglandin E2 (PGE2) levels in culture supernatants by competitive EIA.

RESULTS

We have shown by immunohistochemistry that COX-2 expression was significantly higher (P < 0.01) in tissues with higher levels of inflammatory infiltrates. Expression of COX-2 was detected in gingival epithelium, endothelial cells as well as cells with fibroblast morphology. In vitro studies indicated that gingival fibroblasts (GF) did not express COX-2 constitutively. However, when these cells were challenged with interleukin (IL)-1 beta or bacterial cells (A. actinomycetemcomitans JP2 or B. forsythus ATCC 43037), COX-2 expression as well as COX-2 activity were upregulated. COX-2 expression was upregulated as early as 2 hours post IL-1 beta challenge and was accompanied by a sustained PGE2 release in the culture supernatants. Cyclosporin A (CsA) did not inhibit COX-2 expression induced by bacterial challenge. In contrast, NS-398, a selective inhibitor of COX-2 activity, almost completely abolished PGE2 synthesis by these cells in response to bacterial or cytokine challenge.

CONCLUSIONS

We conclude that COX-2 expression is significantly upregulated in inflamed periodontal tissues. Both inflammatory cytokines such as IL-1 beta and bacterial constituents may be responsible for the enhanced COX-2 expression and PGE2 synthesis in vivo.

Longitudinal evaluation of GCF MMP-3 and TIMP-1 levels as prognostic factors for progression of periodontitis

BACKGROUND

To determine whether matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in gingival crevicular fluid (GCF) could serve as prognostic factors for the progression of periodontitis, we monitored GCF MMP-3 and TIMP-1 and periodontal status of selected sites in 40 medically healthy subjects over a 6-month period.

METHOD

Clinical measurements including gingival index (GI), plaque index, bleeding on probing, suppuration, probing depth (PD), attachment loss (AL), and GCF samples were taken from 2 healthy sites (including sites with gingival recession, GI=0 PD < or =3 mm; AL < or =2 mm) and 2 periodontitis sites (GI > or =1; PD > or =5 mm; AL > or =3 mm) of each patient at baseline, 3-month and 6-month visits by means of sterile paper strips. GCF levels of MMP-3 and TIMP-1 were determined by sandwich ELISA assays.

RESULTS

The mean amounts of MMP-3 and TIMP-1 in diseased sites were significantly higher than in healthy sites (p<0.0001). Significantly higher GCF levels of MMP-3 and TIMP-1 were found at progressing sites than in nonprogressing periodontitis sites (0.001<p<0.01). A progressing site was defined as a site which had > or =2 mm loss of attachment during 6- month study period. GCF levels of MMP-3 were highly correlated with clinical measurements taken at baseline, 3-month and 6-month visits (p<0.001). TIMP-1 levels were only moderately correlated with probing depth and attachment level (p<0.01). Step-wise multiple regression analysis was performed to construct models for the prediction of probing depth and attachment loss increases. The most parsimonious regression models which had the best R2 values included the following variables and accounted for the indicated % of variability. The regression model for the prediction of probing depth increase included MMP-3, smoking pack-years, TIMP-1 and accounted for 53% of the variability. The best model for the prediction of attachment loss increase included MMP-3, smoking pack-years, age, TIMP-1 and explained 59% of the variability.

CONCLUSION

These data indicate that sites with high GCF levels of MMP-3 and TIMP-1 are at significantly greater risk for progression of periodontitis.

Matrix metalloproteinases (MMP-8 and -9) and neutrophil elastase in gingival crevicular fluid of cyclosporin-treated patients

BACKGROUND

Gingival overgrowth (GO) is one of the most important side effects of cyclosporin A (CsA) medication, but its pathogenesis is not completely understood. The aim of this study was to identify and compare collagenase-2 (MMP-8), gelatinase-B (MMP-9), and neutrophil (PMN)-elastase levels in gingival crevicular fluid (GCF) from 15 renal transplant patients receiving CsA therapy and exhibiting CsA GO, 14 patients with gingivitis, and 10 periodontally healthy subjects.

METHODS

Clinical data were obtained on plaque index, papilla bleeding index, and hyperplastic index from each site studied. GCF samples and clinical data were collected from: 2 sites exhibiting CsA GO (CsA GO+) and 2 sites not exhibiting CsA GO (CsA GO-) in each CsA-treated patient; 2 diseased sites in each patient with gingivitis; and 2 healthy sites in each subject with clinically healthy periodontium. CsA GO+ and CsA GO- sites were divided into 2 subgroups as clinically not inflamed (PBI = 0) and inflamed (PBI > or =1). GCF MMP-8, MMP-9, and PMN-elastase levels were analyzed by immunofluorometric assay.

RESULTS

GCF MMP-8 and -9 levels and clinical degrees of gingival inflammation in CsA GO+ sites were similar to those in diseased sites. However, GCF elastase levels were significantly lower in CsA GO+ sites compared to those in diseased sites. GCF MMP-8, -9 and PMN-elastase levels were not different between CsA GO- sites and healthy sites. Additionally, GCF MMP-8 and -9 levels in inflamed CsA GO+ sites were higher but not statistically significantly than those in diseased sites. In contrast, GCF PMN-elastase levels in inflamed CsA GO+ sites were significantly lower than the levels in diseased sites.

CONCLUSIONS

These results show that CsA therapy does not have a significant effect on GCF MMP-8 and MMP-9 levels, but the gingival inflammation seems to be the main reason for their elevations. However, low GCF PMN-elastase levels can be an important factor in the pathogenesis of CsA-induced gingival overgrowth. CsA therapy does not eliminate the potential use of GCF MMP-8 and -9 as future diagnostic markers of gingival inflammation.

Microassay for the detection of elastase activity in the gingival crevice

BACKGROUND, AIMS

A new microassay for the detection of elastase activity (EA) in gingival crevicular fluid (GCF) has been established. GCF was collected with Periopaper strips and quantified in a Periotron.

METHODS

Enzyme activity was measured in a microtiter plate reader, using a fluorometric assay. To ensure quality and precision of the assay, recovery rates were determined at different activities with a recovery of >90%. In a 2nd step, stability of the enzyme was investigated during storage at room temperature, +4 degrees C, -22 degrees C, -88 degrees C. GCF samples retained elastase activity of almost 100% after a storage of 3 days at -22 degrees C. In a group of 12 healthy volunteers, elastase activity was assayed throughout an 18 day experimental gingivitis protocol.

RESULTS

Median activity increased from 481 microU/microl at baseline to 1444 microU/microl at day 18, which was accompanied by the development of the signs of gingivitis. The increase of EA during the experimental phase of the study was highly significant (p<0.001) and correlated well with the increasing severity of gingivitis.

CONCLUSION

The data suggest that elastase activity in GCF is an excellent quantitative measure of gingival inflammation.

Relationship between crevicular aspartate aminotransferase levels and periodontal disease progression

BACKGROUND

Aspartate aminotransferase (AST), an enzyme released from necrotic cells, has been identified in gingival crevicular fluid (GCF), and elevated levels are associated with periodontal tissue destruction. The aim of this study was to examine the relationship between elevated GCF levels of AST and periodontal disease progression.

METHODS

Over a 12-month period, 8 to 10 interproximal sites in 41 periodontitis subjects (PS) and 15 healthy subjects (HS) were monitored. Clinical measurements included relative attachment level (RAL), probing depth, and bleeding on probing (BOP). Semiquantitative levels of GCF AST (< 800 microIU, > or = 800 microIU, and > or = 1,200 microIU) were determined using a chairside assay. At the 6- and 12-month visits, scaling and root planing and prophylaxis were performed in the PS and HS, respectively. Sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) were calculated for 2 diagnostic criteria (AST > or = 800 microIU, AST > or = 1,200 microIU) utilizing 4 thresholds of disease progression as determined by 2 methods (absolute change in relative attachment level and cumulative sum [CUSUM]).

RESULTS

The percentage of sites exhibiting AST > or = 800 microIU, AST > or = 1,200 microIU, and BOP in the PS was significantly (P<0.02) lower at 6 and 12 months compared to baseline. The use of crevicular AST activity to monitor periodontal disease progression was associated with many false-positive results. Overall, low specificities, PPV, and odds ratios were demonstrated by the assay when using 2 diagnostic criteria and 4 thresholds of disease progression. The high NPV suggest that a negative AST test result was indicative of a periodontally stable site.

CONCLUSIONS

These results demonstrate that elevated levels of AST were present at sites that did not subsequently exhibit disease progression. The high prevalence of AST-positive sites due to gingival inflammation diminished the test's ability to discriminate between progressive and stable, but inflamed, sites.

Use of a fluorogenic septapeptide matrix metalloproteinase assay to assess responses to periodontal treatment

BACKGROUND

Quantification of gingival crevicular fluid matrix metalloproteinase activity may provide improved assessment of periodontal disease status and response to treatment. A fluorogenic matrix metalloproteinase substrate assay (FSA) has been developed using a methoxycoumarin-containing septapeptide analog of the alpha2(I) collagen cleavage site. This substrate exhibits increased fluorescence following cleavage by many matrix metalloproteinases, and the enzyme activity can be readily estimated with a fluorimeter. Here we compared this assay with classical methods of periodontal assessment including bleeding on probing, crevicular fluid flow, and probing depth to assess its utility as an indicator of changes in periodontal status and treatment response.

METHODS

Complete measurements of probing depth were obtained for Ramfjord teeth on subjects who had been previously treated for periodontitis. Subjects were subsequently divided into groups based on existing periodontal disease severity: gingivitis (n = 21), stable periodontitis (n = 41), and severe periodontitis (n = 50). Crevicular fluid volume, bleeding on probing, and FSA were measured at each Ramfjord tooth or substitute. After baseline measurements, subjects received subgingival scaling and prophylaxis; 3 months later, they were reassessed.

RESULTS

FSA measurements were positively associated with severity of disease at baseline. After treatment there were substantial reductions of FSA in gingivitis (approximately 51%; P <0.01) and severe periodontitis (approximately 45%; P <0.001), but not in stable periodontitis (13%; P >0.2). All groups showed a positive association between FSA measurements and higher bleeding scores at individual sites. FSA measurements were also positively associated with crevicular fluid flow at baseline, but after treatment there was a approximately 67% decrease (P <0.01) in the highest crevicular fluid flow class. There were significant reductions of FSA at follow-up for sites with probing depths between 0 to 3 mm (23%; P <0.05) and 4 to 6 mm (31%; P <0.05). However, the largest reduction was for sites with probing depth between 7 to 9 mm (49%; P <0.001).

CONCLUSIONS

These results indicate that monitoring patients by measurement of matrix metalloproteinase levels in gingival crevicular fluid with the quenched fluorescent substrate assay provides estimates of inflammatory status, periodontal destruction, and response to treatment, especially in more severe periodontitis lesions.

Relationship of the substance P to indicators of host response in human gingival crevicular fluid

BACKGROUND

The substance P (SP) level in human gingival crevicular fluid (GCF) was studied in relation to clinical periodontal variables and to various indicators of host response in the GCF.

METHODS

GCF was collected from periodontal sites with gingival inflammation and shallow or moderately deep pocket in 48 subjects. The total amount of SP and the substances based on host response factors in a 30-s sample were determined by ELISA and enzymatic methods.

RESULTS

Significant correlation was found between SP and probing depth (r= 0.637, p<0.001), while correlation was weak between SP and either gingival (r= 0.177, p=0.23) or plaque index (r=0.008, p=0.96). SP also showed significant correlation with the indicators of host response: prostaglandin E2, aspartate aminotransferase, alkaline phosphatase, myeloperoxidase, interleukin-1beta, tumor necrosis factor-alpha, interleukin-8 and monocyte chemoattractant protein-1 (r=0.434-0.867, p<0.01-0.001).

CONCLUSION

These results indicate that neuropeptide SP in GCF may have a potential as an indicator of periodontal inflammation and the host response.

Inhibition of human gingival gelatinases (MMP-2 and MMP-9) by metal salts

OBJECTIVES

The interaction between metal ions and the oral environment is a major subject matter in dental research. Matrix metalloproteinases (MMPs) have been implicated in several pathologic oral processes such as periodontal tissue destruction, root caries, tumour invasion and temporomandibular joint disorders. The aim of this work was to test the effect of Zn, Cu, Sn and Hg ions on the activity of the major gingival gelatinolytic MMPs.

METHODS

Gingival explants were cultured overnight in DMEM and the activity of secreted enzymes was analyzed by gelatin zymography in buffers containing different metal ion concentrations. The major gelatinolytic proteinases present in the conditioned media were characterized as MMP-2 and MMP-9 by immunoprecipitation with specific antibodies. The eletrophoretic bands were scanned and the transmittance values were analyzed with the Sigmagel software (Sigma).

RESULTS

ZnSO4 was a strong inhibitor of MMP-2 (I50 = 15 microM) and MMP-9 (I50 = 40 microM), whereas CuSO4, HgSO4 and SnCl2 showed less efficient inhibition potential.

SIGNIFICANCE

Our findings show that the activity of oral tissue MMPs may be modulated by metal ions present in the oral environment. Therefore, the accumulation of metals in connective tissue may interfere with the formation and resorption of the extracellular matrix components.

Increased interleukin-1beta concentration in gingival crevicular fluid as a characteristic of periodontitis

BACKGROUND

The levels of interleukin-1beta (IL-1beta) have been reported to be higher in sites with periodontitis than in healthy controls. This may be the result of a more severe inflammation and/or constitutional differences in IL-1beta production. Our aim was to test the hypothesis that the level of IL-1beta in gingival crevicular fluid (GCF) is a characteristic trait of periodontitis, regardless of the degree of tissue destruction. As a secondary aim, we investigated the correlation between IL-1beta and neutrophil elastase. An untreated population was used.

METHODS

GCF samples from inflamed sites in 13 patients with gingivitis (GG), and from inflamed sites with shallow (GP) and deep (PP) pockets in 18 patients with periodontitis were collected. Interleukin-1beta, elastase-alpha-1-antitrypsin complex (E-A1AT), alpha-1-antitrypsin (A1AT), and alpha-2-macroglobulin (A2MG) were measured with ELISA. Elastase activity was measured with a specific substrate.

RESULTS

The concentration of IL-1beta was significantly higher in PP than in GG, but no significant differences were detected between PP and GP. A weak positive correlation between the elastase activity and IL-1beta was also observed. The elastase activity had a tendency to be higher in PP, although no significant difference was found among the 3 groups. The concentrations of E-A1AT, A1AT, and A2MG were similar in the 3 types of sites.

CONCLUSIONS

The levels of IL-1beta in GCF were increased in samples from periodontitis patients, regardless of the severity of disease at the sampled site, suggesting that the levels of IL-1beta are typical of a given patient.

In situ localization and characterization of active proteases in chronically inflamed and healthy human gingival tissues

BACKGROUND

Studies have indicated an important role for host-derived proteases in the pathogenesis of periodontal disease. The objectives of this study were: 1) to develop an assay measuring protease activity in situ and 2) to localize and characterize the enzymatic activity in intact inflamed and healthy gingiva.

METHODS

Gingival specimens were prepared and over-laid with a quenched fluorescent substrate. Protease activity was visualized by fluorescence microscopy and correlated with histologic features.

RESULTS

In inflamed tissues, enzymatic activity was detected mainly in the connective tissue (predominantly matrix metalloproteases) and, to some extent, in the epithelium (predominantly serine proteases). In contrast, clinically healthy tissues failed to exhibit significant amounts of protease activity. Quantitative and qualitative characteristics of protease activity in intact tissues were found to be pH dependent.

CONCLUSIONS

The method described here enabled assessment of active proteases in intact tissues where cell-cell and cell-matrix interactions had been maintained. Our results indicate that there are substantial differences in the distribution of specific proteases between clinically healthy and inflamed periodontal tissues.

Chitinase in whole and glandular human salivas and in whole saliva of patients with periodontal inflammation

In recent studies the existence of a chitinase in various mammals, like man, was described. The aim of the present study was to find out whether salivas of periodontally healthy and inflamed humans also contain chitinase activity. Chitinase activity, assayed with the substrate 4-methylumbelliferyl-beta-D-N,N',N"-triacetylchitotrioside, was shown to be present in human whole saliva, with an activity level and apparent molecular mass (35 kDa) that were comparable with those of the human serum enzyme. Both lysozyme and beta-N-acetylhexosaminidase could be separated from chitinase by means of Bio-Gel P-100 gel filtration chromatography. The enzyme was also present in glandular saliva of parotid, palatine, submandibular and sublingual glands. The chitinase activity was not of oral epithelial, bacterial or plaque bacterial origin and was not correlated with the activity of salivary amylase. A comparative study of whole salivas of periodontally healthy controls and gingivitis and periodontitis subjects showed that only in the case of periodontitis there was a significant increase of the specific chitinase activity. The latter enzyme showed a gel filtration pattern that was comparable with that of the enzyme from controls. The measured albumin levels in saliva and the absence of correlation between the chitinase activity levels in plasma and saliva from periodontitis patients indicated that the (increased) chitinase activities did not originate from blood leakage to the oral cavity.