Discussion: Attachment level changes in destructive periodontal diseases

Neutrophil Dysfunctions, IL-8, and Soluble L-Selectin Plasma Levels in Rapidly Progressive Versus Adult and Localized Juvenile Periodontitis: Variations According to Disease Severity and Microbial Flora

We used flow cytometry to analyze the expression of adhesion molecules and the oxidative burst of whole-blood polymorphonuclear neutrophils (PMN) from 26 patients with periodontitis. Three different clinical entities were studied: adult periodontitis (AP), localized juvenile periodontitis (LJP), and rapidly progressive periodontitis (RPP). Unstimulated PMN from the patients showed reduced Lewis x, sialyl-Lewis x, and L-selectin expression relative to those from healthy control subjects. These alterations were present whatever the severity of periodontal disease. However, PMN from RPP patients showed increased basal H2O2 production and decreased L-selectin shedding. These latter impairments, which correlated with increased IL-8 plasma levels, could contribute to initial vascular damage. In addition, decreased IL-8 priming of H2O2 production by PMN from RPP patients could account for a lower bactericidal capacity of PMN, leading to the large number of bacteria in the subgingival region of RPP patients. Soluble L-selectin plasma levels were also decreased in the RPP group, indicating more severe or diffuse endothelial damage. These abnormalities were not found in the patients with less destructive forms of periodontitis (AP and LJP). Porphyromonas gingivalis, a bacterial pathogen known to increase IL-8 production by PMN, was found in the periodontal pockets of RPP patients only. These results show links among PMN abnormalities, the clinical form of periodontitis, and the gingival bacterial flora.

Issues in the evaluation of clinical trials of periodontitis: a clinical perspective

The goals of clinical trials designed to establish claims for equivalency or superiority of treatment for periodontitis must be clearly stated and defined in terms of measurable and meaningful response variables. It is suggested that these clinical trials use designs that compare new treatment methods to basic periodontal therapy which consists of thorough scaling and root planing, oral hygiene instruction, and regular maintenance care. The primary response variable should be clinical attachment level. It is important to document changes in probing depth since this is a meaningful measure to many clinicians. Gingival inflammation and bleeding should be used as secondary response variables because these are not necessarily indicative of progressive periodontal destruction. Radiographic measures of disease may be useful as primary response variables if safe, reproducible and valid methods of measuring change are utilized. Microbiological monitoring should be a secondary response variable because of numerous questions concerning sampling methodology, quantitative expression of data, and meaningful interpretation in terms of relevance to disease activity. The length of periodontitis trials should be set at a minimum of 9 months if claims of superiority or equivalency are made compared to basic periodontal therapy. Calibration trials should be included and measurement error should be expressed in terms that are meaningful to the clinician while retaining statistical validity. Statistical methods for determining change should take into account site and subject heterogeneity, bursts of change and gradual change over time. It is important that statistical techniques be used that detect change as early as possible and that appropriate consideration be given to the clinical implications of the type, magnitude and duration of change in outcome variables.

Microbiology of healthy and diseased periodontal sites in poorly controlled insulin dependent diabetics

A group of poorly-controlled insulin dependent diabetes mellitus (IDDM) patients were examined in a cross-sectional design for total microbial levels, microbial incidence, and the percent levels of selected periodontal microorganisms. These organisms were selected on the basis of prior reports that associated them with either periodontal disease or health. One periodontally-healthy and one periodontally-diseased site were examined in each IDDM patient. Increased levels of the periodontal pathogens Prevotella intermedia, P. melaninogenica spp., Bacteroides gracilis, Eikenella corrodens, Fusobacterium nucleatum and Campylobacter rectus (formerly Wolinella recta) were found at the periodontal diseased sites. Increased prevalence of the organisms P. intermedia, P. melaninogenica spp., and C. rectus were found at the diseased sites. A significantly higher percentage of P. intermedia was found at the sites exhibiting deep pockets and attachment loss.

Closed versus open debridement of facial grade II molar furcations

Clinical responses of facial grade II molar furcations to closed (C) versus open (O) debridement were evaluated. 25 teeth were treated at baseline (BL) with scaling/root planning (S/RP) and evaluated at 4 months. 12 of the teeth were then treated with open flap debridement and the remaining teeth were treated with further S/RP. Clinical parameters of plaque, gingival inflammation, bleeding on probing, gingival fluid flow, pocket depth and probing attachment level were taken at BL, 4, 7, 10, 13 and 16 months. Pairwise differences were determined between visits and a t-test was applied to differences for C and O. For both treatment groups, the greatest changes in clinical parameters occurred from BL - 4 months. Plaque and gingival inflammation showed a gradual reduction from BL throughout the study for both groups. A reduction in pocket depth from BL - 16 months was noted in both groups (mid-furcal, C = 1.5 mm, O = 1.2 mm; root prominence, C = 1.02 mm, O = 0.84 mm)! There was a gain in probing attachment level in the midfurcal area for the C group (0.6 mm) while the O group lost (-0.46 mm). There were no statistically significant differences found for any clinical parameter between closed and open debridement. The presence of plaque and bleeding at a furcal site had not significant effect on treatment response.

A cross-sectional analysis of aspartate aminotransferase in human gingival crevicular fluid

Previous investigation has shown that the concentration of aspartate aminotransferase (AST), an established serum marker for cardiac and liver damage in humans, is significantly elevated in samples of gingival crevicular fluid (GCF) from ligated teeth in beagle dogs. This paper reports on a cross-sectional study of the relationships between AST in GCF and clinical indices of human periodontal disease in 60 patients with mild to moderate adult periodontitis. AST standardized to a 30-second collection interval (AST30) showed substantial (multiple regression R2 = 0.61) association with summary indices of patient disease status, modest association (partial R2 = 0.22) with tooth disease status within patient, and weaker (partial R2 = 0.12) but statistically significant association with site-to-site variation in disease at the same tooth. AST concentration showed modest (R2 = 0.30) between-patient relationship with clinical indices, but no clinically significant relationship with these indices between sites within patients, suggesting a rough proportionality between accumulated enzyme and GCF volume at sites with varying stages of disease. The relationship between GCF volume and probing depth also appears central to interpretation of enzyme assays. Clinical measures of past periodontitis and current inflammatory disease are cross-sectionally related to variation in AST30, across patients and sites within the same patient. Considerable residual variation, especially elevated AST30 in the absence of clear signs of disease, may result from varying levels of current disease activity, not reflected in clinical measures.

Cross-sectional and longitudinal reliability for clinical measurement of attachment loss

Progression of marginal periodontitis in humans is characterized by acute exacerbations during short periods of time followed by periods of remission. The analytical procedures used to distinguish actively progressing sites from non-progressing sites within an individual's dentition are controversial. The purpose of the present investigation was to use measurements of probing depth and attachment level from a prospective longitudinal study of episodic periodontal disease progression to examine measurement and diagnostic reliability. In 10 systemically healthy adult human subjects with untreated advanced periodontitis, probing depth and attachment levels were measured at baseline and every 30 days for 10 to 12 months. Measurements were made at 6 sites of each tooth using an acrylic onlay as a reference point and a pressure sensitive probe. Replicate measurements were made on sites showing apparent changes in attachment loss of 2 mm or more in a month, and their contralateral counterparts. Cross-sectional reliability was described by means and standard deviations for the absolute differences between replicate measurements: 0.63 +/- 0.87 mm for anterior teeth, 0.58 +/- 0.80 mm for premolars and 0.69 +/- 0.91 mm for molars. The mean differences tended to decrease with increasing time on study and tended to be greater in deeper pockets. Longitudinal reliability was described by analyzing site-specific serial attachment level measurements across the study time period. Maximum likelihood methods were used to estimate false positive and false negative diagnostic rates associated with the diagnosis of attachment loss based on minimum threshold levels of 1 and 2 mm. The use of a 1 mm threshold resulted in estimated false positive rates of 0.08 to 0.11 and false negative rates of 0.11 to 0.15.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of laminin receptor in gingival tissue and its interaction with tooth cementum laminin

1. A gingival epithelial cell surface receptor for laminin was isolated from bovine gingival tissue by affinity chromatography on laminin. 2. The protein bound by the affinity matrix from octylglucoside extracts of gingival membrane preparation eluted from the column with the cation-free buffer containing EDTA, and exhibited a mol. wt of 67 kDa. 3. The 67 kDa protein following radioiodination was incorporated into liposomes, which showed a specific affinity towards laminin-coated surfaces, as well as to the tooth cementum. 4. The results provide for the first time evidence for the existence of a gingival cell surface laminin receptor, and indicate that the maintenance of the cemento-epithelial junction involves the interaction between the cementum laminin and its receptor on gingival epithelium.

A 6-year study on the pattern of periodontal disease progression

The present longitudinal radiographic investigation was designed to study the change in the alveolar bone height over 6 years in relation to tooth type, age and the presence of previous bone loss in a group of 142 subjects (age 18-67 years) who were not under systematic periodontal treatment. The subjects were examined radiographically at baseline, and after 2 and 6 years, and sites showing significant (greater than or equal to 1 mm) change in the alveolar bone height during 2 consecutive examinations were identified. 90.2% of all examined sites showed no bone loss during the 6 years, while 8.6% and 1.2% of the sites exhibited bone loss during one or both examination periods, respectively. 3 groups of subjects within the studied population were identified. Approximately 5% of the subjects had high rates of periodontal disease progression whilst approximately 70% demonstrated very few or no sites with bone loss, and approximately 25% had a moderate level of disease progression during the study period. The results also showed that the number of sites exhibiting alveolar bone loss during the study period varied with respect to tooth type, age of the patient and presence of bone loss at baseline. In addition, significantly different rates of bone loss were disclosed with relation to tooth type (P less than 0.01), age (P less than 0.0001) and initial bone loss (P less than 0.01). It was concluded that periodontal disease progression occurs infrequently and may take the form of discrete or recurrent episodes of loss of periodontal support which can be influenced by the location of the site, age of the subject and previous periodontal disease experience.

Assessment of relationships between site-specific variables

The assessment of relationships between site-specific variables has been a matter of controversy because of the claim that periodontal sites within individuals can be used as independent observations in statistical models. One problem with this approach is the unreliability of the calculated Type I and Type II error rates. Another problem is that such inappropriate analysis may prohibit a correct assessment of causal relationships between site-specific variables. The host-factor can act as an effect modifier and modulate the magnitude of the site-specific effects and/or the host-factor can act as a confounder by superimposing a patient-effect on the studied site-specific effects leading to bias. As a result, site-specific biological mechanisms of disease progression may be misinterpreted. Sites can be used as the experimental unit of analysis, but the sampling design from which the site-specific data originated should not be ignored.

The effect of treatment on IgG, IgA, IgM and alpha-2-macroglobulin in gingival crevicular fluid from patients with chronic adult periodontitis

With a technique for sampling, processing and analysis of gingival crevicular fluid (GCF) that allows multiple constituents to be analysed from a sample collected on a filter paper strip, we have examined IgG, IgA, IgM and alpha-2-macroglobulin (alpha 2M) in GCF from patients with chronic adult periodontitis. Clinical data and GCF were collected before and 3 months after root planing and scaling, and analysed to determine trends for the population. A statistically-significant decrease in the percentage of sites with bleeding on probing, erythema and supragingival plaque was observed 3 months after therapy. The mean amount of each glycoprotein in GCF decreased dramatically at 3 months. In contrast, the mean volume of GCF was virtually identical at the two evaluations. The IgG/IgA and IgG/IgM ratios in GCF were elevated when compared with human serum suggesting the preferential occurrence of IgG in GCF. Correlation of the four glycoproteins with GCF volume and with enzyme markers of the acute inflammatory response in GCF revealed a relationship between arylsulphatase (a lysosomal enzyme), fluid influx, and the passage of larger molecular-weight glycoproteins (alpha 2M, IgM) into the gingival crevice.