Development of a biochemical profile for gingival crevicular fluid. Methodological considerations and evaluation of collagen-degrading and ground substance-degrading enzyme activity during experimental gingivitis

Approximal plaque pH lowering after sugar intake in a periodontally infected dentition

OBJECTIVES

The aim of this study was to evaluate the effect of periodontal inflammation on the approximal plaque pH after a sucrose rinse.

MATERIALS AND METHODS

Thirty-two periodontitis patients (aged 38-72 years; 9M/23F) were included. All patients were in need of periodontal surgery. Two non-adjacent interdental spaces, one healthy (no bleeding on probing [BoP] and probing pocket depth [PPD] < 4 mm) and one periodontally diseased (BoP and PPD ≥5 mm) were selected. Before and after surgery, the approximal plaque pH was measured before and after 2, 5 and 10 min after a 1-min rinse with sucrose solution.

RESULTS

In periodontally diseased interdental spaces, a significant pH drop was seen 5 min after rinsing. In healthy spaces and after surgery, a significant pH drop was seen after 2 min. A multilevel regression analysis showed that greater probing pocket depths were significantly associated with pH change measured 5 min after rinsing (p < .05). Further on, the approximal pH drop after a sucrose rinse tended to be delayed in dentitions with ≥10% of PPD ≥5 mm (p = .052).

CONCLUSIONS

The results suggest that an ongoing periodontal inflammation could temporarily neutralize acidic metabolic products after a sugar challenge. This may further suggest that plaque pH measured after a sugar rinse might be used to identify an ongoing periodontal disease.

MicroRNA-34 expression in gingival crevicular fluid correlated with orthodontic tooth movement

OBJECTIVES

To explore the expression of miR-34a and its effect on expression of matrix metalloproteinases (MMPs) during orthodontic tooth movement (OTM).

MATERIALS AND METHODS

Twenty patients, age 12-18 years old, who underwent orthodontic treatment were enrolled. The expression of miR-34a and MMPs (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, and MMP-14) were detected in gingival crevicular fluid by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction at different time points. The miR-34a mimics or inhibitors were transfected into human periodontal ligament (hPDL) cells, and the MMP expression was measured by ELISA.

RESULTS

The miR-34 expression in GCF on both the tension and pressure sides after orthodontic treatment were significantly downregulated, while the levels of MMPs were significantly upregulated compared with baseline level. The levels of miR-34 and MMPs returned to baseline level 3 months after orthodontic treatment. The expression of miR-34 was negatively correlated with the expression of MMP-2, MMP-9, and MMP-14. After transfection with miR-34, the MMP-2, MMP-9, and MMP-14 expression by hPDL cells were significantly downregulated compared with miR-control and miR-34 inhibitor.

CONCLUSIONS

Downregulated miR-34 expression was positively correlated with MMP-2, MMP-9, and MMP-14 expression. The miR-34a transfection into hPDL cells inhibited expression of MMPs. The results suggest that miR-34a is involved in expression of MMPs during OTM.

Methodological evaluation of gingival crevicular fluid volume and neutrophil elastase levels: sequential sampling, length of sampling time and two different sampling methods

Objectives: The mechanisms underlying the formation and composition of gingival crevicular fluid (GCF) and its flow into and from periodontal pockets are not understood very well. The aim of this study was to evaluate the length of sampling time and sequential sampling of GCF neutrophil elastase (NE) enzyme levels by using intracrevicular and orifice methods.Material and methods: Twenty adults (mean age of 41.8 years, ranged 31-60 years, 18 males and 2 females) with chronic periodontitis were enrolled and all completed the 3-d study. GCF was collected by both intracrevicular and intrasulcular methods, 720 samples of GCF were collected. In first, second and third day, the length of sampling time in seconds (s) and order were '5- 10-30-s'; '10- 30- 5-s' and '30- 5- 10-s,' respectively. GCF elastase levels were determined by hydrolysis of neutrophil specific substrate N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroanilide.Results: NE activity (µU) and NE activity/volume (µU/µl) were significantly different for order of sampling (p < .05), but not for the length of sampling time (p>.05).Conclusions: Within the limits of this study, the choice of sampling technique in GCF-profile studies seems to be a critical decision as it has the potential to affect the GCF volume and NE activity.

Effect of orthodontic forces on levels of enzymes in gingival crevicular fluid (GCF): A systematic review

Objective:

Orthodontic force application releases multiple enzymes in gingival crevicular fluid (GCF) for activation, resorption, reversal, deposition of osseous elements and extracellular matrix degradation. The current systematic review critically evaluated all existing evidence on enzymes in orthodontic tooth movement.

Methods:

Literature was searched with predetermined search strategy on electronic databases (PubMed, Scopus, Embase), along with hand search.

Results:

Initial search identified 652 studies, shortlisted to 52 studies based on PRISMA. Quality assessment further led to final inclusion of 48 studies (13 moderately and 35 highly sensitive studies). Primary outcomes are significant upregulation in GCF levels of enzymes-aspartate aminotransferase (AST), alkaline phosphatase (ALP), matrix metalloproteinases (MMPs), lactate dehydrogenase (LDH), β-glucuronidase (βG), tartrate resistant acid phosphatase (TRAP), acid phosphatase (ACP) and down regulation in cathepsin B (Cb). Site specificity is shown by ALP, TRAP, AST, LDH, MMP9 with levels at compression site increasing earlier and in higher quantities compared with tension site. ALP levels are higher at tension site only in retention. A positive correlation of LDH, ALP and AST is also observed with increasing orthodontic force magnitude.

Conclusions:

A strong evidence of variation in enzymes (ALP, AST, ACP TRAP, LDH, MMPs, Cb) in GCF is found in association with different magnitude, stages and sites of orthodontic force application.

Interleukin-6 and interleukin-10 gene polymorphisms and the risk of further periodontal disease progression

Susceptible genotypes to periodontal disease are associated with disease onset and progression. The aim of this study was to examine the effect of gene polymorphisms on the risk of further disease progression and the need for further treatment among adults with chronic periodontal disease. Sixty-seven patients diagnosed with chronic periodontitis were grouped according to genotype status and risk of further progression of disease and tooth loss. All individuals were clinically evaluated for probing pocket depth, clinical attachment loss and bleeding on probing at baseline and 45 days after treatment. Blood samples were collected at baseline and genotyping of the polymorphisms in IL-6 (rs1800796) and IL-10 (rs1800872) genes were performed by PCR. Following DNA separation and genotyping, 65.7% of the patients were homozygous carriers of the IL-6 -572G and 49.3% were carriers of the IL-10 -592A allele. Individuals at risk of disease progression ranged from 7.5% to 62.7% based on the criteria used. Carriers of the IL-10 -592A allele were significantly associated with BOP ≥ 30% and therefore exhibited a higher risk of further periodontal breakdown (p = 0.018) with an odds ratio of 1.18. None of the other definitions of disease progression were significantly associated with the examined IL-6 and IL-10 genotypes (p > 0.05). IL-10 polymorphism was associated with an increased risk of further disease progression and the potential need for further treatment following non-surgical periodontal treatment. Susceptible IL-6 genotypes were not associated with the risk of persisting or recurrent disease activity.

Secretory microRNA-29 expression in gingival crevicular fluid during orthodontic tooth movement

Secretory microRNAs (miRNAs) have been used increasingly as biomarkers for cancers, autoimmune diseases and inflammatory diseases. They are reported as being freely circulated or encapsulated in microvesicles such as exosomes. This study was performed to elucidate the presence of miRNAs with exosomes in human gingival crevicular fluid (GCF), and the expression profile of miRNA-29 during orthodontic tooth movement. Four healthy volunteer and fifteen orthodontic patients were enrolled in the study. Secretory miRNA in GCF was collected and analyzed using a bioanalyzer, realtime PCR and Western blot analysis. The expression profile of secretory miR-29 family in GCF was analyzed during the course of canine retraction for 6 weeks. The results demonstrated the presence of miRNAs in the GCF. After series of ultracentrifugation and RT-PCR array, exosome-depleted fractions and pellets were isolated and we found that secretory miRNAs were detected in both the exosome-associated fraction and the exosome-depleted supernatant fraction; however, the concentration of miRNAs was higher in the exosome-associated fraction than in the exosome-depleted fraction suggesting a close association between the secretory miRNAs and exosomes in GCF. We also demonstrated the increased expression profiles of miR-29 family during six weeks of orthodontic tooth movement in humans. Secretory miRNAs are present in GCF and secretory miRNA-29 family expression profiles increase during the tooth movement in humans. Secretory miRNA-29 in GCF could serve as potential biomarkers for periodontal remodeling.

The effects of IL-10 gene polymorphism on serum, and gingival crevicular fluid levels of IL-6 and IL-10 in chronic periodontitis

OBJECTIVE

Anti-inflammatory cytokines play a crucial role in periodontitis by inhibiting synthesis of pro-inflammatory cytokines. The purpose of this study was to evaluate the effect of interleukin-10 (-597) gene polymorphism and genotype distributions on chronic periodontitis (CP) development and IL-6 and IL-10 levels in gingival crevicular fluid (GCF) and serum before and after non-surgical periodontal treatment.

MATERIAL AND METHODS

The study population consisted of 55 severe generalized CP patients as CP group and 50 healthy individuals as control group. Plaque index, gingival index, probing depth and clinical attachment level were recorded and GCF and blood samples were taken at both the baseline and the sixth week after non-surgical periodontal treatment. PCR-RFLP procedure was used for gene analyses and cytokine levels were measured via ELISA.

RESULTS

IL-10 genotype distribution was significantly different between CP and control groups (p=0.000, OR:7, 95%CI, 2.83-60.25). Clinical measurements significantly improved in the CP group after periodontal treatment (p<0.05). Periodontal treatment significantly decreased GCF IL-6 and IL-10 levels. No significant difference was found in clinical parameters between IL-10 AA and AC+CC genotypes at both the baseline and the sixth week (p>0.05). Sixth week GCF IL-10 levels were significantly lower in patients carrying IL-10 AC+CC genotype compared to the patients carrying IL-10 AA genotype (p<0.05). Serum IL-6 and IL-10 levels were lower in patients carrying the IL-10 AA genotype compared to patients with IL-10 AC+CC genotype, but the difference was not significant (p>0.05).

CONCLUSION

IL-10 AA genotype carriers had lower IL-6 and IL-6/10 levels in serum; however, GCF IL-6/10 levels were similar in both genotypes. Within the limitations of our study, a possible association between IL-10(-597) gene polymorphism and CP might be considered.

The effect of restorative materials on cytokines in gingival crevicular fluid

OBJECTIVE

Composition of the restorative materials may cause inflammatory responses by monocyte activation and changes in the levels of cytokine released from different cells. Interleukin-6 (IL-6), interleukin-8 (IL-8) and Tumor necrosis factor alpha (TNF-α) are important cytokine for evaluating of the inflammatory process. The aim of this study was to evaluate the different restorative materials used in class V cavities effect on gingival crevicular fluid inflammatory cytokine levels.

DESIGN

60 individuals having Class V carious cavities participated in the study. Cavities were restored with FiltekZ250, DyractXP, Fuji IX, Cavex avalloy restorative materials. Changes in clinical and biochemical parameters were evaluated before restorations, seven and 21days after restorations. Contralateral tooth intact enamel surface was determined as control side. Periotron8000 device was used for detection of GCF volume. Cytokine level of GCF was evaluated by Human ELISA kits. Data were analyzed using Mann-Whitney U test and Wilcoxon signed ranks test. The correlations between clinical parameters and biochemical parameters were examined by Spearman's rank correlation analysis.

RESULTS

After restorative treatments PI and GI scores were decreased compared with baseline evaluations. There was a significant difference in GCF levels between experimental and control sites in all groups. GCF IL-6 levels in all groups except Filtek Z250, GCF IL-8 levels in all groups except Fuji IX, GCF TNF-α level in only Fuji IX showed significant differences between experimental and control sites.

CONCLUSIONS

The obtained data supported that all of the tested materials caused changes in GCF cytokine levels.

An evaluation and comparison of myeloperoxidase enzymatic activity during initial orthodontic alignment: an in vivo study

INTRODUCTION

Tooth movement during orthodontic treatment is possible because of mechanical force-induced inflammation and remodelling in the periodontal ligament. Variation in the inflammatory response might be anticipated with initial aligning archwires of different composition. Myloperoxidase (MPO) is an enzyme found in neutrophil granules that represents an important marker of inflammation. The aim of this study was to measure MPO enzyme activity during initial alignment with orthodontic arch wires of different alloy types.

MATERIALS AND METHODS

MPO activity was determined in gingival crevicular fluid (GCF) from a sample of 60 patients divided into three groups during initial orthodontic alignment with three types of arch wire (0.016-inch superelastic (SE) NiTi; 0.016-inch heat-activated (HANT) NiTi and 0.00175-inch multistranded stainless steel). MPO activity was measured at baseline, 2 hours, 7 and 14 days after appliance activation.

RESULTS

MPO activity was significantly increased in GCF at 2 hours (P < 0.01), 7 and 14 days in all groups compared to baseline. Enzymatic activity was highest in the SE NiTi group followed by HANT and multistranded stainless steel groups but with no significant difference between SE NiTi and HANT groups.

CONCLUSION

SE and HANT NiTi arch wires produce an increased inflammatory response based upon MPO activity during initial levelling and alignment compared to multistranded stainless steel.

Gingival crevicular fluid proteomes in health, gingivitis and chronic periodontitis

OBJECTIVE

The aim of this study was to compare the proteome composition of gingival crevicular fluid obtained from healthy periodontium, gingivitis and chronic periodontitis affected sites.

BACKGROUND

Owing to its site-specific nature, gingival crevicular fluid is ideal for studying biological processes that occur during periodontal health and disease progression. However, few studies have been conducted into the gingival crevicular fluid proteome due to the small volumes obtained.

METHODS

Fifteen males were chosen for each of three different groups, healthy periodontium, gingivitis and chronic periodontitis. They were categorized based on clinical measurements including probing depth, bleeding on probing, plaque index, radiographic bone level, modified gingival index and smoking status. Gingival crevicular fluid was collected from each patient, pooled into healthy, gingivitis and chronic periodontitis groups and their proteome analyzed by gel electrophoresis and liquid chromatography electrospray ionization ion trap tandem mass spectrometry.

RESULTS

One hundred and twenty-one proteins in total were identified, and two-thirds of these were identified in all three conditions. Forty-two proteins were considered to have changed in abundance. Of note, cystatin B and cystatin S decreased in abundance from health to gingivitis and further in chronic periodontitis. Complement proteins demonstrated an increase from health to gingivitis followed by a decrease in chronic periodontitis. Immunoglobulins, keratin proteins, fibronectin, lactotransferrin precursor, 14-3-3 protein zeta/delta, neutrophil defensin 3 and alpha-actinin exhibited fluctuations in levels.

CONCLUSION

The gingival crevicular fluid proteome in each clinical condition was different and its analysis may assist us in understanding periodontal pathogenesis.

Myeloperoxidase enzymatic activity is increased in patients with different levels of dental crowding after initial orthodontic activation

INTRODUCTION

Orthodontic tooth movement implies application of forces that generate an inflammatory process. The myeloperoxidase (MPO) enzyme is found inside neutrophil granules. MPO activity indirectly reflects the level of inflammation. The aim of this study was to measure MPO activity in gingival crevicular fluid (GCF) and whole saliva in orthodontic patients with different levels of dental crowding at the alignment phase of orthodontic treatment with the same archwires.

METHODS

Twenty patients were classified according to the irregularity index into 2 groups: severe and minimum crowding (10 in each group). MPO activity was evaluated in GCF and saliva at 0 and 2 hours, and 7 and 14 days after the orthodontic appliances were activated. MPO activity was measured using the modified Bradley-Bozeman technique.

RESULTS

In both groups, the maximum activity was at 2 hours (P <0.05) after activation. MPO activity remained elevated until day 7, and values similar to baseline were found at day 14 in the GCF and saliva samples. Enzymatic activity did not show statistical differences between the groups.

CONCLUSIONS

The amount of dental crowding does not seem to influence MPO activity, which showed similar patterns in GCF and saliva, but the values in GCF reflected the inflammatory changes more accurately than did the values in saliva. The quantification of MPO activity is a useful biologic marker as an indirect measurement of inflammation generated with tooth movement independent of the amount of crowding.

Role of interleukin-6 in orthodontically induced inflammatory root resorption in humans

Objective

To determine the interleukin (IL)-6 levels in gingival crevicular fluid (GCF) of patients with severe root resorption after orthodontic treatment and investigate the effects of different static compressive forces (CFs) on IL-6 production by human periodontal ligament (hPDL) cells and the influence of IL-6 on osteoclastic activation from human osteoclastic precursor (hOCP) cells in vitro.

Methods

IL-6 levels in GCF samples collected from 20 patients (15 and 5 subjects without and with radiographic evidence of severe root resorption, respectively) who had undergone orthodontic treatment were measured by ELISA. The levels of IL-6 mRNA in hPDL cells and IL-6 protein in conditioned medium after the application of different uniform CFs (0, 1.0, 2.0, or 4.0 g/cm² for up to 72 h) were measured by real-time PCR and ELISA, respectively. Finally, the influence of IL-6 on mature osteoclasts was investigated by using hOCP cells on dentin slices in a pit-formation assay.

Results

Clinically, the IL-6 levels were significantly higher in the resorption group than in the control group. In vitro, IL-6 mRNA expression significantly increased with increasing CF. IL-6 protein secretion also increased in a time- and magnitude-dependent manner. Resorbed areas on dentin slices were significantly greater in the recombinant human IL-6-treated group and group cultured in hPDL cell-conditioned medium with CF application (4.0 g/cm²) than in the group cultured in hPDL cell-conditioned medium without CF application.

Conclusions

IL-6 may play an important role in inducing or facilitating orthodontically induced inflammatory root resorption.

Clinical outcomes of periodontal therapy are not influenced by the ATC/TTC haplotype in the IL8 gene

BACKGROUND AND OBJECTIVE

Although chronic periodontitis (CP) is a multifactorial condition, few studies have investigated the potential association of gene variants with the outcome of periodontal therapy. In a previous study, we reported that variants in the interleukin-8 (IL8) gene were associated with CP in a Brazilian population. The aim of this nonrandomized study was to investigate whether genetic susceptibility to CP, conferred by the presence of the IL8 ATC/TTC haplotype, influences the clinical outcomes of nonsurgical periodontal therapy and the IL-8 protein levels in the gingival crevicular fluid.

MATERIAL AND METHODS

Forty-one individuals were grouped according to the presence (susceptible to CP; n = 21) or absence (not susceptible to CP; n = 20) of the IL8 ATC/TTC haplotype. These individuals received nonsurgical periodontal therapy from one periodontist, who was blinded to the genetic status of each patient, and follow up continued for 45 d. The clinical parameters and gingival crevicular fluid samples were collected at baseline and on day 45. The IL-8 levels were determined by an ELISA. The data were subjected to the Mann-Whitney U-test, Wilcoxon and Spearman tests and to multiple logistic-regression analysis.

RESULTS

No significant differences between patients with or without the IL8 ATC/TTC haplotype were found for the outcome of nonsurgical periodontal therapy and IL-8 levels. The multiple logistic-regression analysis did not show a statistically significant association between the IL8 haplotype and the variables studied.

CONCLUSION

In this longitudinal clinical study, we observed that neither the outcome of nonsurgical periodontal therapy nor the IL-8 levels were influenced by the IL8 ATC/TTC CP-susceptibility haplotype. Additional studies of CP patients from other ethnic populations are necessary to confirm these results.

A pilot study evaluating non-contact low-frequency ultrasound and underlying molecular mechanism on diabetic foot ulcers

Non-contact low-frequency ultrasound (NCLF-US) devices have been increasingly used for the treatment of chronic non-healing wounds. The appropriate dose for NCLF-US is still in debate. The aims of this pilot study were to evaluate the relationship between dose and duration of treatment for subjects with non-healing diabetic foot ulcers (DFUs) and to explore the correlation between wound healing and change of cytokine/proteinase/growth factor profile. This was a prospective randomised clinical study designed to evaluate subjects with non-healing DFUs for 5 weeks receiving standard of care and/or NCLF-US treatment. Subjects were randomly assigned to one of the three groups: application of NCLF-US thrice per week (Group 1), NCLF-US once per week (Group 2) and the control (Group 3) that received no NCLF-US. All subjects received standard wound care plus offloading for a total of 4 weeks. Percent area reduction (PAR) of each wound compared with baseline was evaluated weekly. Profiles of cytokines/proteinase/growth factors in wound fluid and biopsied tissue were quantified to explore the correlation between wound healing and cytokines/growth factor expression. Twelve DFU patients, 2 (16·7%) type 1 and 10 (83·3%) type 2 diabetics, with an average age of 58 ± 10 years and a total of 12 foot ulcers were enrolled. Average ulcer duration was 36·44 ± 24·78 weeks and the average ABI was 0·91 ± 0·06. Group 1 showed significant wound area reduction at weeks 3, 4 and 5 compared with baseline, with the greatest PAR, 86% (P < 0·05); Groups 2 and 3 showed 25% PAR and 39% PAR, respectively, but there were no statistically significant differences between Groups 2 and 3 over time. Biochemical and histological analyses indicated a trend towards reduction of pro-inflammatory cytokines (IL-6, IL-8, IL-1β, TNF-α and GM-CSF), matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF) and macrophages in response to NCLF-US consistent with wound reduction, when compared with control group subjects. This proof-of-concept pilot study demonstrates that NCLF-US is effective in treating neuropathic diabetic foot ulcers through, at least in part, inhibiting pro-inflammatory cytokines in chronic wound and improving tissue regeneration. Therapeutic application of NFLU, thrice (3) per week, renders the best wound area reduction.

Haplotypes of susceptibility to chronic periodontitis in the Interleukin 8 gene do not influence protein level in the gingival crevicular fluid

OBJECTIVE

Previously, we identified that the ATC/TTC haplotype formed by polymorphisms in the Interleukin-(IL)8 gene conferred susceptibility to chronic periodontitis (CP). The aim of the study was to investigate whether the IL8 haplotype ATC/TTC was associated with the volume of gingival crevicular fluid (GCF), the concentration of interleukin IL-8 in the GCF, as well as periodontal conditions in patients with CP in comparison to controls without CP.

METHODS

Seventy-nine individuals (CP: n=41, controls: n=38) were grouped according to the presence (susceptible for CP) or absence (not susceptible for CP) of the IL8 ATC/TTC haplotype. After periodontal clinical evaluation, they were subdivided by the presence or absence of CP. GCF was collected from each patient and the IL-8 levels were determined by ELISA. The GCF volume of each subject was measured by means of a calibrated electronic device. Comparisons of means between carriers and non-carriers of the ATC/TTC haplotype were evaluated using the Mann-Whitney test. Linear regression and stepwise linear regression analysis were used to analyse the association of the GCF volume with potential covariates and their contribution for the phenotype.

RESULTS

We did not find significant differences of both periodontal conditions and IL-8 concentration in the GCF of patients with the presence or absence of the IL8 ATC/TTC haplotype. However, the GCF volume was significantly higher amongst the patients affected by CP that are absent for the IL8 ATC/TTC haplotype. In addition, linear regression analysis showed a statistically significant association between GCF volume and CP, IL8 haplotype ATC/TTC and IL-8 concentration.

CONCLUSIONS

The IL8 haplotype of susceptibility to CP was neither associated with IL-8 cytokine levels nor with clinical periodontal parameters. Also, CP, IL8 haplotype and IL-8 concentration showed a positive association with the GCF volume levels in the studied patients.

Lactate dehydrogenase activity in gingival crevicular fluid as a marker in orthodontic tooth movement

Objectives:

This study aims at analyzing the changes in gingival crevicular fluid (GCF) lactate dehydrogenase (LDH) activity during orthodontic movement.

Methods:

Twenty patients all requiring first premolar extractions were selected and treated with conventional straight wire mechanotherapy. Canine retraction was done using 125 g Nitinol closed coil springs. The maxillary canine on one side served as the experimental site while the contralateral canine served as the control. GCF was collected from the canines before initiation of retraction, then 1 hour after initiating canine retraction, followed by 1 day, 7 days, 14 days and 21 days. GCF LDH levels were estimated and compared with the control site.

Results

The results revealed significantly higher LDH levels on the 7^th, 14^th and 21^st day at the sites where orthodontic force had been applied. The levels also showed a significant increase from 0 hour to the 21st day. Peak levels were seen on 14^th and 21^st day following initiation of retraction.

Conclusions:

The study showed that LDH could be successfully estimated in the GCF and its increased levels could indicate active tooth movement, which could aid the clinician in monitoring active orthodontic tooth movement.

Surgery-first accelerated orthognathic surgery: postoperative rapid orthodontic tooth movement

PURPOSE

Clinically, we have observed the phenomenon of postoperatively accelerated orthodontic tooth movement in patients who had orthognathic surgery. This phenomenon lasts for a period of 3 to 4 months. However, the underlying mechanisms of this phenomenon have not been well studied yet. The purpose of this prospective clinical pilot study was to study the postoperative changes in bone physiology and metabolism and the corresponding responses in the dentoalveolus, such as the changes in tooth mobility.

MATERIALS AND METHODS

Twenty-two consecutive adult patients who had 2-jaw orthognathic surgery were included in this study. The levels of serum alkaline phosphatase and C-terminal telopeptide of type I collagen (ICTP), as well as the tooth mobility of the maxillary and mandibular incisors based on the Periotest method (Siemens AG, Bensheim, Germany), were examined preoperatively and 1 week, 1 month, 2 months, 3 months, and 4 months postoperatively. The data were analyzed statistically.

RESULTS

Both tooth mobility of the maxillary and mandibular incisors and ICTP significantly increased from 1 week to 3 months postoperatively and then decreased to their preoperative levels in the fourth month postoperatively. The changes in tooth mobility were significantly in correspondence with the changes in ICTP. The alkaline phosphatase level significantly increased from the first to fourth month postoperatively, but it was not significantly correlated to the changes in tooth mobility.

CONCLUSION

The orthognathic surgery triggers a 3- to 4-month period of higher osteoclastic activities and metabolic changes in the dentoalveolus postoperatively, which possibly accelerates postoperative orthodontic tooth movement.

Gingival tissue transcriptomes in experimental gingivitis

AIMS

We investigated the sequential gene expression in the gingiva during the induction and resolution of experimental gingivitis.

MATERIAL AND METHODS

Twenty periodontally and systemically healthy non-smoking volunteers participated in a 3-week experimental gingivitis protocol, followed by debridement and 2-week regular plaque control. We recorded clinical indices and harvested gingival tissue samples from four interproximal palatal sites in half of the participants at baseline, Day 7, Day 14 and Day 21 (the "induction phase"), and at Day 21, Day 25, Day 30 and Day 35 in the other half (the "resolution phase"). RNA was extracted, amplified, reversed transcribed, amplified, labelled and hybridized using Affymetrix Human Genome U133Plus2.0 microarrays. Paired t-tests compared gene expression changes between consecutive time points. Gene ontology analyses summarized the expression patterns into biologically relevant categories.

RESULTS

The median gingival index was 0 at baseline, 2 at Day 21 and 1 at Day 35. Differential gene regulation peaked during the third week of induction and the first 4 days of resolution. Leucocyte transmigration, cell adhesion and antigen processing/presentation were the top differentially regulated pathways.

CONCLUSIONS

Transcriptomic studies enhance our understanding of the pathobiology of the reversible inflammatory gingival lesion and provide a detailed account of the dynamic tissue responses during the induction and resolution of experimental gingivitis.

Myeloperoxidase activity is increased in gingival crevicular fluid and whole saliva after fixed orthodontic appliance activation

INTRODUCTION

Orthodontic tooth movement uses mechanical forces that result in inflammation in the first days. Myeloperoxidase (MPO) is an enzyme found in polymorphonuclear neutrophil (PMN) granules, and it is used to estimate the number of PMN granules in tissues. So far, MPO has not been used to study the inflammatory alterations after the application of orthodontic tooth movement forces. The aim of this study was to determine MPO activity in the gingival crevicular fluid (GCF) and saliva (whole stimulated saliva) of orthodontic patients at different time points after fixed appliance activation.

METHODS

MPO was determined in the GCF and collected by means of periopaper from the saliva of 14 patients with orthodontic fixed appliances. GCF and saliva samples were collected at baseline, 2 hours, and 7 and 14 days after application of the orthodontic force.

RESULTS

Mean MPO activity was increased in both the GCF and saliva of orthodontic patients at 2 hours after appliance activation (P <0.02 for all comparisons). At 2 hours, PMN infiltration into the periodontal ligament from the orthodontic force probably results in the increased MPO level observed at this time point.

CONCLUSIONS

MPO might be a good marker to assess inflammation in orthodontic movement; it deserves further studies in orthodontic therapy.

Detection of root resorption using dentin and bone markers

OBJECTIVES - To test the hypothesis that during root resorption, organic matrix proteins and cytokines from the surrounding bone and dentin are released into the gingival crevice. MATERIAL AND METHODS - Subjects with mild (<2 mm loss) and severe root resorption (>2 mm) were identified. Control group subjects with no loss of root structure or undergoing orthodontic treatment were also identified. Gingival crevicular fluid (GCF) was collected non-invasively from the mesial and distal sides of each of the four upper incisors by using filter paper strips. The eluted GCF was used for analysis using western blot and enzyme-linked immunosorbent assay (ELISA) techniques. Antibodies used were against osteopontin (OPN), (osteoprotegerin) OPG, and receptor activator of nuclear factor kappa B ligand (RANKL). RESULTS - Western blot analysis showed differential expression of OPN, OPG, and RANKL in the control and root resorbed subjects. However, processed forms of these proteins were only observed in the root resorbed subjects. Results from ELISA with OPG antibodies revealed a difference in OPG concentration between the control and root resorption groups. ELISA results with RANKL antibodies did show a statistically significant difference between the control group and the two study groups. The ratio RANKL/OPG was statistically higher in subjects with severe root resorption than in the control subjects. CONCLUSIONS - Preliminary results confirm the presence of matrix proteins and cytokines in the GCF of root resorbed subjects. Further, OPG was locally present in excess amounts over RANKL and an increased RANKL/OPG in the study groups could be correlated with an increased bone resorption activity during orthodontic tooth movement.

Comparison of levels of inflammatory mediators IL-1beta and betaG in gingival crevicular fluid from molars, premolars, and incisors during rapid palatal expansion

INTRODUCTION

Previously, we reported fluctuation of the levels of the inflammatory mediators interleukin-1beta (IotaL-1beta) and beta-glucuronidase (betaG) in gingival crevicular fluid (GCF) from the maxillary first molars in adolescents undergoing rapid palatal expansion. In this study, we compared the responses of IL-1beta and betaG in the GCF of the maxillary first molars, first premolars, and central incisors during palatal expansion at the same patients.

METHODS

Nine patients requiring palatal expansion were selected at the postdoctoral orthodontic clinic at Columbia University College of Dental Medicine. Each patient received periodontal prophylaxis and instructions in proper home care including rinsing with chlorhexidine. Four weeks after periodontal prophylaxis, a modified hyrax appliance was placed. The jackscrew was activated twice daily until the appropriate expansion was achieved. GCF samples were collected before and after periodontal prophylaxis and during passive wearing of the appliance, active orthodontic treatment, and retention. Fluid samples were collected with filter paper strips and analyzed by ELISA and time-dependent fluorometry for IL-1beta and betaG, respectively. The values recorded after periodontal prophylaxis were used as the baseline. Paired t tests were used to compare mediator levels at baseline with the levels obtained at each subsequent observation.

RESULTS

The results validate that IL-1beta and betaG are present in the GCF of adolescents, and, although their level decreases after a strict regimen of plaque control, it increases during orthodontic or orthopedic movement. Moreover, this study demonstrates that both heavy and light forces evoke increased levels of IL-1beta and betaG, stronger forces cause higher levels of inflammatory mediators, and both IL-1beta and betaG respond to direct and indirect application of mechanical force to teeth.

CONCLUSIONS

This investigation corroborates previous findings that an inflammatory process occurs during application of mechanical force to teeth. Although this inflammation is considered relatively aseptic, additional inflammation, such as that induced by plaque accumulation, must be avoided during orthodontic or orthopedic treatment.

Cytokines in crevicular fluid and orthodontic tooth movement

This review aimed to evaluate studies on cytokines in the gingival crevicular fluid (GCF) during orthodontic treatment, summarizing the regulation patterns of the most commonly studied cytokines and exploring their clinical implications. To achieve this, a number of key databases were searched using MESH terms and free text terms. An additional search was made by reference tracking. The procedures suggested by the QUOROM statement were followed. Data from the included studies were extracted into orthodontic mechanics, GCF sampling/handling methods, and cytokine measurements. From the 85 relevant studies identified, 23 studies could be included. Common drawbacks consisted mainly of inadequacies in the study design (e.g. short duration and small number of study subjects). The most consistent result was a peak of cytokine levels at 24 h. Associations existed between prostaglandin E(2) (PGE(2)) and interleukin-1beta (IL-1beta) and pain, velocity of tooth movement, and treatment mechanics. Interleukin-1beta and PGE(2) showed different patterns of up-regulation, with IL-1beta being more responsive to mechanical stress and PGE(2) more responsive to synergistic regulation of IL-1beta and mechanical force. The results might be taken to support, at the cellular level, the use of light continuous forces for orthodontic treatment.

Alkaline phosphatase activity in gingival crevicular fluid during canine retraction

OBJECTIVES

The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans.

SETTING AND SAMPLE POPULATION

Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy.

EXPERIMENTAL VARIABLE

Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control.

OUTCOME MEASURE

Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated.

RESULTS

The results show significant (p < 0.05) changes in alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect.

CONCLUSIONS

The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.

Salivary glycoproteins as indicators of oral diseases

The present study deals with the estimation of total carbohydrate, protein bound carbohydrate, bound fucose and sialic acid along with total protein in disease conditions like gingivitis, periodontitis and their comparison with the normals.The neutral hexose values in gingivitis (8.08±2.20mg/100mg protein) and periodontitis (12.5±2.16mg/ 100mg protein) decreased significantly when expressed per 100 mg protein compared to normals (19.8±1.89mg/100mg protein). This might be because of higher protein concentration in these two clinical conditions. The ethanol insoluble hexose values were significantly reduced in both these conditions compared to controls (3.71±1.64,5.91±1.63,7.65±0.86mg/100mg protein respectively). The ethanol soluble hexose values were also found to be drastically reduced. This decrease in saliva appears to be characteristic feature of oral diseases. In gingivitis and periodontitis fucose level was found to be increased compared to normals when expressed as a function of salivary volume. However in terms of protein concentration the values in gingivitis (2.95±1.59), periodontitis (3.26±0.98) and normals (3.20±0.50mg/100mg) were not different. Sialic acid in ethanol insoluble fraction of salivary samples mg/100mg protein was found to be significantly reduced in both gingivitis (0.78±0.33) and periodontitis (0.95±0.31) compared to controls (1.92±0.33).

Analysis of the relationship between the severity of periodontal destruction and proteoglycan metabolism of gingiva and gingival crevicular fluid

BACKGROUND

Although it is well-described that proteoglycans (PGs) are among the major non-collagenous components of the matrix which are degraded during periodontal diseases, the relationship between PG metabolism and seventy of periodontal breakdown, the extent of degradation of PGs together with the resulting end-products, and the elimination pathways of these catabolic end-products is likely to need further clarification.

OBJECTIVE

The main aim of the present study was to analyze the possible impact of severity of periodontal destruction on PG metabolism of gingiva and gingival crevicular fluid (GCF).

MATERIAL AND METHODS

For this purpose, gingiva and GCF samples obtained from patients (n = 45) exhibiting sites (n = 57) with moderate periodontal breakdown (MP) or severe periodontal breakdown (SP) were analyzed for PG metabolism via spectrophotometric determination of uronic acid levels. Gingiva and GCF samples were obtained from the same sites in every patient to analyze the possible relationship between uronic acid content of gingival tissue and GCF.

RESULTS

No significant differences were found in uronic acid levels between sites with MP and SP (p > 0.05). The uronic acid content of GCF and gingiva showed significant overlaps between MP and SP sites and uronic acid levels did not present any constant correlation with the clinical parameters (p > 0.05). In a similar manner, uronic acid content of GCF and gingival tissue was not correlated (p > 0.05).

CONCLUSION

The lack of a significant correlation between the uronic acid content of gingival tissue and GCF may suggest that the passage of PG metabolites from gingiva to GCF is likely to be under the influence of multifactorial interactions rather than being linear. As a general measure of PG metabolism, uronic acid levels do not seem to be related with the severity of periodontal destruction and tend to act as different measures when compared to traditional clinical parameters.

Development of an in vitro microassay for glucose quantification in submicrolitre volumes of biological fluid

Glucose quantification in serum or plasma is traditionally based on a colourimetric enzymatic assay using commercially available assay kits. Sample volumes of blood or serum are usually in the range of a few microlitres to a few millilitres. However, for biological fluids such as gingival crevicular fluid (GCF), which can only be sampled in submicrolitre volumes, such assays have proven unsuitable. The aim of this study was to develop a reliable and reproducible assay for quantifying glucose in submicrolitre samples of GCF. The assay involved modification of a commercially available kit for glucose quantification. Test solutions of (i) serum and (ii) serum with added glucose at known concentrations (range 50-400 mg/dl) were prepared to simulate GCF and GCF enriched with glucose, respectively. Submicrolitre volumes (range 0.2 microl to 0.8 microl) of the test solutions were added to the reagent solution (200 microl) using a Hamilton syringe. The reaction was performed under standard conditions of time and temperature. The colour change was assayed spectrophotometrically at 492 nm. The results showed that this microassay is sufficiently sensitive to detect 50 mg/dl glucose in 0.2 microl of sample and indicate that the accuracy and sensitivity of this assay make it suitable for glucose quantification in submicrolitre volumes of GCF, particularly relevant to investigations of the relationship between diabetes mellitus and chronic inflammatory periodontal disease. In vivo evaluation of this novel microassay was performed using GCF samples taken from periodontally healthy and chronic periodontitis patients. Using non-parametric analysis, the results showed that the assay detected statistically significant differences in glucose concentrations between the two patient groups (p < 0.05). Higher glucose levels were detected at the periodontally diseased sites. For each patient, the GCF-glucose: blood-glucose ratio was calculated. The results show that this ratio was higher in the periodontitis group (1: 2) when compared to the healthy group (1: 9). In conclusion, the results of this investigation have shown that this microassay can quantify glucose in GCF and that GCF-glucose levels are higher at periodontitis sites.

The buccale puzzle: The symbiotic nature of endogenous infections of the oral cavity

The indigenous, 'normal', microflora causes the majority of localized infectious diseases of the oral cavity (eg, dental caries, alveolar abscesses, periodontal diseases and candidiasis). The same microflora also protects the host from exogenous pathogens by stimulating a vigorous immune response and provides colonization resistance. How can a microflora that supports health also cause endogenous oral disease? This paradoxical host-symbiont relationship will be discussed within the dynamic of symbiosis.Symbiosis means 'life together' - it is capable of continuous change as determined by selective pressures of the oral milieu. Mutualistic symbiosis, where both the host and the indigenous microflora benefit from the association, may shift to a parasitic symbiosis, where the host is damaged and the indigenous microflora benefit. Importantly, these are reversible relationships. This microbial dynamism, called amphibiosis, is the essential adaptive process that determines the causation of endogenous oral disease by a parasitic microflora or the maintenance of oral health by a mutualistic microflora.Complex microbial consortiums, existing as a biofilm, usually provide the interfaces that initiate and perpetuate the infectious assault on host tissue. The ecology of the various oral microhabitats is critical for the development of the appropriate selecting milieux for pathogens. The microbiota associated with dental caries progression is primarily influenced by the prevailing pH, whereas periodontal diseases and pulpal infection appear to be more dependent on redox potential. Candidiasis results from host factors that favour yeast overgrowth or bacterial suppression caused by antibiotics. Oral health or disease is an adventitious event that results from microbial adaptation to prevailing conditions; prevention of endogenous oral disease can occur only when we realize that ecology is the heart of these host-symbiont relationships.

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.

Analysis of human gingival tissue and gingival crevicular fluid beta-glucuronidase activity in specific periodontal diseases

BACKGROUND

Beta-glucuronidase (betaG) is one of the enzymes involved in the destruction of non-collagenous components of the extracellular matrix. It is also considered an indicator or predictor of periodontal disease activity. The present study was conducted to determine the presence and the levels of betaG activity in gingival tissue and gingival crevicular fluid (GCF) in periodontal disease and health status. The validity of 2 expressions of data, total betaG activity versus betaG concentration, and the correlations between clinical periodontal status and betaG profile was also evaluated.

METHODS

betaG activities in gingival tissues and GCF samples from 57 individuals, divided into 3 equal groups of adult periodontitis (AP), early-onset periodontitis (EOP), and periodontally healthy subjects were spectrophotometrically examined.

RESULTS

Both patient groups had higher betaG levels in both gingiva and GCF than controls. Significant differences were observed among all groups when total GCF betaG activities were examined (P <0.05). However, the difference between AP and controls was not significant when concentration values were compared (P >0.05). The highest GCF betaG activity, with both expressions, was detected in EOP group. No absolute correlations between clinical parameters and betaG activity were observed, except for random correlations in the patient groups with mean total betaG activities. Also GCF/gingiva betaG levels and the 2 expressions did not show absolute correlations.

CONCLUSIONS

The findings of the present study confirm the relationship between betaG activity and periodontal diseases. The differences in data concerning GCF total betaG activity and betaG concentration may suggest that they are not matching measures. Data presentation seems to be an important factor in GCF/enzyme profile studies.

Interleukin-1beta and beta-glucuronidase in gingival crevicular fluid from molars during rapid palatal expansion

This study examined whether the inflammatory mediators interleukin (IL-1beta) and beta-glucuronidase (betaG) are present in the gingival crevicular fluid (GCF) of children undergoing rapid palatal expansion and whether their levels vary upon activation of the appliance and movement of the maxillary first molars. Nine adolescent patients who needed palatal expansion were studied. Each patient received a periodontal prophylaxis and instruction in proper home care, including rinsing with chlorhexidine. Four weeks later, a modified Hyrax appliance was inserted. The jackscrew was activated twice daily until the appropriate expansion was achieved. GCF samples were collected at 2 pretreatment observation periods and 9 observation periods after placement of the appliance. Samples were collected with filter paper strips and analyzed by means of ELISA and time-dependent fluorometry for IL-1beta and betaG, respectively. The values recorded at the observation period 2 weeks after the periodontal prophylaxis were used as baseline. Paired t tests were used to compare mediator levels at this baseline to the levels obtained at each of the subsequent observations. The results indicate that (1) betaG and IL-1beta are present in GCF of young, healthy individuals, (2) their levels decrease following a strict regimen of plaque control, (3) orthodontic/orthopedic forces evoke changes in the levels of the inflammatory mediators IL-1beta and betaG in the periodontal tissues that can be detected in GCF. The results of this study support the hypothesis that mechanical stimulus causes an inflammatory reaction within the periodontal tissues, which in turn may trigger the biological processes associated with bone remodeling.

Crevicular fluid level of beta-glucuronidase in relation to clinical periodontal parameters and putative periodontal pathogens in early-onset periodontitis

Analysis of beta-glucuronidase (betaG) in the gingival crevicular fluid (GCF) provides an indication of neutrophil influx into the crevicular environment. The aim of this study was to test the hypotheses that: (1) betaG is significantly elevated in individuals with early-onset periodontitis (EOP) and that betaG activity correlates with disease severity; and (2) betaG level may reflect the local bacterial challenge in the gingival crevice. The study subjects consisted of a sub-sample of individuals examined in the National Survey of Oral Health of United States Children, which was undertaken during the 1986/87 school year. A total of 249 individuals were selected based on presence or absence of clinical attachment loss at baseline. The individuals were examined a second time 6 years later and the clinical attachment loss was assessed, and subgingival plaque and GCF were collected. The subjects were classified into 3 types of EOP and a control group. BetaG activity in the GCF and the levels of 7 putative micro-organisms in the pocket were assessed. The generalized EOP group had the highest betaG activity, followed by the localized and incidental EOP groups, and the controls, respectively. There was a significant increase in betaG activity with the increase in probing depth. Also, sites with bleeding on probing had a significantly higher betaG activity than sites without bleeding. However, the effect of gingival inflammation on betaG activity was more evident in the generalized and localized EOP groups. Sites harboring high levels of one or more of the micro-organisms tended to have high betaG activity. There were moderate differences between the organisms with respect to their effect on betaG activity, but sites with high numbers of Porphyromonas gingivalis, Prevotella intermedia, or Treponema denticola also had the highest betaG activity. The present findings suggest that betaG activity in GCF from patients with EOP can be of value in the early identification of individuals at higher risk of developing EOP The findings also suggest that host mechanisms leading to higher betaG activity in EOP represent systemic responses and are only partly related to the presence of local factors at the site-level.

Periotron 8000: calibration characteristics and reliability

The Periotron is an instrument designed to quantify submicrolitre volumes of fluid sampled on a filter paper strip. To date 3 models have been manufactured: the Periotron 600 (1976), the Periotron 6000 (1983) and more recently the Periotron 8000 (1995). This paper investigated for the first time the calibration characteristics and reliability of the Periotron 8000. The fluids under investigation were: de-ionised water, human serum, fetal bovine serum and an ultrafiltrate of fetal bovine serum. Quantitative analysis was studied by recording a series of Periotron readings over a volume range of 0-1.0 microliters for each fluid. The average of 5 Periotron values for each particular fluid was then plotted versus the respective fluid volume. Qualitative changes in fluid composition versus Periotron Scores were also analysed. Volume conversion for Periotron scores using both Periotron MLCONVRT software and a best fit equation selected from TableCurve 2D software compared well. The results of this study revealed that: 1) differences in calibration fluid composition (e.g. protein content) are reflected in the Periotron scores; 2) positioning of filter paper strip between the jaws of the Periotron should be standardised, 3) calibration of the Periotron 8000 seems to be consistent over a 1-wk interval.

Molecular size distribution analysis of human gingival proteoglycans and glycosaminoglycans in specific periodontal diseases

In order to determine the molecular-size distribution of gingival proteoglycans (PGs) and glycosaminoglycans (GAGs) both in periodontal health and disease states, gingival tissues were obtained from patients with early onset periodontitis (EOP) and adult periodontitis (AP) and also from periodontally healthy subjects. Gel filtration chromatography of gingival PGs revealed different profiles for periodontally diseased and healthy gingiva. Healthy gingiva was mainly composed of high-molecular size proteins and PGs, while diseased gingival tissue presented a decrease in high-molecular size PG forms and a shift towards low-molecular size proteins and PGs. This indicates the degradation of PG macromolecules during periodontal disease activity. Furthermore, this shift towards low-molecular size forms was more intense in EOP patients when compared to AP patients. Gel filtration of gingival GAGs also demonstrated depolymerization of GAGs, with low-molecular size GAGs being more intense in periodontally diseased gingiva, while healthy gingival GAGs profile was mainly composed of high-molecular size GAGs. Similar to the profile of gingival PGs, low-molecular size gingival GAGs were more prominent in gingival tissue from patients with EOP. These findings suggest that both PGs and GAGs, essential components of the extracellular matrix (ECM), are depolymerized during periodontal disease activity, which is more prominent in EOP. Since the basic feature of periodontal disease is matrix degradation, ECM components, more specifically PGs and GAGs, are likely to provide valuable information for a better understanding of periodontal disease activity.

Cytokines modulate routes of collagen breakdown. Review with special emphasis on mechanisms of collagen degradation in the periodontium and the burst hypothesis of periodontal disease progression

In this paper, we review recent work on collagen degradation, 2 main routes of breakdown are described and their relevance during healthy and inflammatory conditions of the periodontium is discussed. Special attention is paid to the possible role of cytokines, in particular interleukin 1 (IL-1) and transforming growth factor beta (TGF-beta), on the modulation of collagen phagocytosis and metalloproteinase production. IL-1 has been shown to have a dual function in collagen digestion. It inhibits the intracellular phagocytic pathway, but at the same time, it strongly promotes extracellular digestion by inducing the release of collagenolytic enzymes like collagenase. TGF-beta has an opposite effect on both pathways and antagonizes IL-1. Collagenase is released in an inactive form, and a considerable fraction of the proenzyme may become incorporated in the extracellular matrix. This reservoir of latent enzyme can be activated (for instance by plasmin), leading to a sudden and extensive breakdown of the collagenous fibre meshwork. It is suggested that this phenomenon may also take place during progressive periodontitis and could explain an episodic nature of collagenolysis, clinically resulting in bursts of attachment loss (burst hypothesis).

Interleukin-8 and beta-glucuronidase in gingival crevicular fluid

Polymorphonuclear leukocytes (PMN) play a critical role in the host's response to the subgingival microflora. Interleukin-8 (IL-8) is a potent chemotactic and activating factor for PMN. In this study, the presence of IL-8 in gingival crevicular fluid (GCF) was examined in relation to the PMN indicator beta-glucuronidase (beta G), as well as clinical parameters of chronic inflammatory periodontal disease. Data was obtained from 30 patients with periodontitis and 14 healthy controls. For the control group, GCF and clinical data were obtained only once. For the periodontitis patients, clinical data and GCF samples were collected prior to treatment, and GCF samples were again collected 2 weeks after scaling and root planing. Comparing control and periodontitis patients prior to treatment, IL-8 concentration was lower in the patients with periodontitis. Scaling and root planing resulted in either an increase or a decrease in total IL-8 and IL-8 concentration GCF. A reduction in total IL-8 or IL-8 concentration was accompanied by a corresponding reduction in beta G activity. An increase in total IL-8 or IL-8 concentration after scaling and root planing was associated with an increase in beta G activity in some patients and a reduction in beta G activity in other patients. The periodontitis patients who did not demonstrate a linkage between IL-8 and beta G activity in GCF were those individuals with the highest beta G activity prior to treatment. As elevated beta G activity in GCF has been associated with an increased risk for probing attachment loss, the absence of a direct relationship between IL-8 in GCF and PMN recruitment into the gingival crevice may characterize individuals at risk for progression of periodontitis.

Permeability of the gingival tissues to IgM during an experimental gingivitis study in man

Changes in the permeability of the underlying vasculature of the gingival crevice region may occur either as part of an inflammatory response during gingivitis or as a response to trauma during collection of gingival crevicular fluid IgM was selected as a marker of permeability and the concentration in gingival crevicular fluid was determined immunochemically by dot blotting, using rabbit antihuman IgM specific for mu chain. Gingival crevicular fluid samples were derived from experimental (non-cleaning) and control (cleaning) sites in six individuals participating in a 28-day experimental gingivitis study using a split-mouth protocol. The fluid was collected by a filter-paper method. At each site, four gingival crevicular fluid samples were collected for 5 s each over a 3-min period and a fifth sample was collected after a further 6 min. IgM was detected in 7/30 experimental strips at baseline (after intensive professional prophylaxis) and this increased to 21/30 by 24 days: control values were 13/30 and 12/30, respectively. The data indicate that IgM was detected with greater frequency as gingivitis becomes evident, suggesting increased permeability in response to plaque accumulation. IgM was detected in 17/120 of the first strip samples, collected over the 66-day study period, whereas in the fifth strip samples IgM was detected in 68/120, and the concentration of IgM in gingival crevicular fluid also increased, indicating that sequential collection induced permeability. It is concluded that the permeability of the gingiva changes in response to both an inflammatory stimulus and trauma due to collection.

A longitudinal study of various crevicular fluid components as markers of periodontal disease activity

In order to examine the relationship of possible crevicular biochemical parameters to attachment loss (ALOSS), 330 sites from 8 untreated adult patients were monitored longitudinally at 3-month intervals, for up to 1 year. Attachment levels were measured with a force-sensing probe and an acrylic stent in duplicates at each study point. Crevicular samples were collected and used for the determination of the following 11 markers: number of polymorphonuclear leukocytes (PMNs), prostaglandin E2 (PGE2), osteocalcin (OC), alkaline phosphatase (ALP), collagenase (COL), beta-glucuronidase (BG), antigenic and functional elastase (AEL and FEL), alpha-1 antitrypsin (a1AT), alpha-2 macroglobulin (a2M) and aspartate aminotransferase (AST). 10 sites with ALOSS of > or = 1.5 mm per 3 months (active sites) and 43 sites with negligible changes (inactive sites) were identified. Total amounts of ALP, BG and COL were found to be significantly higher in active as compared to inactive sites, prior to significant ALOSS, without any significant differences in crevicular fluid volume and clinical indices. When biochemical parameters were expressed as ratios to the number of PMNs, PGE2/ PMNs was significantly elevated in active sites. The capacity of such individual parameters to distinguish between active and inactive sites was limited. However, linear discriminant analysis using total amounts of PGE2, COL, ALP, a2M, OC and AEL showed more significant diagnostic values (sensitivity: 80%, specificity: 91%). These findings suggest that the combination of several biochemical parameters in crevicular fluid could give more information to predict future clinical ALOSS.

The measurement of acid and alkaline phosphatase in gingival crevicular fluid during orthodontic tooth movement

This study examines acid and alkaline phosphatase activities in gingival crevicular fluid (GCF) to learn whether bone turnover dynamics can be monitored in human subjects during orthodontic tooth movement. Three female subjects were observed longitudinally to assess tooth movement, plaque, and inflammation. For each subject, one randomly selected premolar served as the control and was not treated, and another was moved buccally with 100 gm of force. The GCF was collected weekly and assayed for phosphatases. Alkaline phosphatase peaked between the first and third weeks, followed by an increase in acid phosphatase between the third and sixth weeks. After the first week, tooth movement averaged 0.9 mm. Additional 0.9 mm of movement occurred during the next 3 weeks, followed by 1.4 mm during weeks 4 to 6. Thirty additional patients, randomly divided into headgear/biteplate, bionator, and control groups, were also sampled cross-sectionally at the maxillary first molars. The GCF phosphatase activities were assessed as functions of location on the tooth, treatment modality, duration of treatment, gingival inflammation, and plaque accumulation. The plaque index did not show a relationship to either acid or alkaline phosphatase activity on the mesial or distal in the treated groups. However, alkaline phosphatase increased with inflammation on the distal in treated groups and acid phosphatase was consistently higher on the mesial than on the distal in the treatment groups. Alternating peaks of acid and alkaline phosphatase were found in the GCF of treated teeth as functions of treatment duration. The sequence of these changes is similar to that reported for alveolar bone turnover in a rodent orthodontic tooth movement model. We conclude that phosphatase activities in GCF may be a useful means for monitoring tissue responses to orthodontic treatment.

Current concepts in diagnosis and treatment of periodontitis

This article describes some areas of periodontal research and current opinions regarding detection of disease progression, as well as risk indicators and risk factors associated with disease progression. Longitudinal probing of periodontal attachment level is considered the gold standard for detection of disease activity although there are problems with this concept. Digital subtraction radiography can assist in the detection of minor changes of alveolar bone height and density. Risk factors such as composition of subgingival plaque and gingival crevicular fluid, as well as the effect of smoking are discussed. Adjunctive treatment with both antibiotics and nonsteroidal anti-inflammatory drugs, systemic or local, seems to be helpful in some forms of disease. Immunization to prevent colonization of tooth surfaces and pockets by periodontal pathogens does not seem to be feasible in the near future.