Assessing the progression of chronic periodontitis using subgingival pathogen levels: a 24-month prospective multicenter cohort study.

BACKGROUND: The diagnosis of the progression of periodontitis presently depends on the use of clinical symptoms (such as attachment loss) and radiographic imaging. The aim of the multicenter study described here was to evaluate the diagnostic use of the bacterial content of subgingival plaque recovered from the deepest pockets in assessing disease progression in chronic periodontitis patients. METHODS: This study consisted of a 24-month investigation of a total of 163 patients with chronic periodontitis who received trimonthly follow-up care. Subgingival plaque from the deepest pockets was recovered and assessed for bacterial content of Porphyromonas gingivalis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans using the modified Invader PLUS assay. The corresponding serum IgG titers were measured using ELISA. Changes in clinical parameters were evaluated over the course of 24 months. The sensitivity, specificity, and prediction values were calculated and used to determine cutoff points for prediction of the progression of chronic periodontitis. RESULTS: Of the 124 individuals who completed the 24-month monitoring phase, 62 exhibited progression of periodontitis, whereas 62 demonstrated stable disease. The P. gingivalis counts of subgingival plaque from the deepest pockets was significantly associated with the progression of periodontitis (p < 0.001, positive predictive value = 0.708). CONCLUSIONS: The P. gingivalis counts of subgingival plaque from the deepest pockets may be associated with the progression of periodontitis.

Salivary pathogen and serum antibody to assess the progression of chronic periodontitis: a 24-mo prospective multicenter cohort study.

BACKGROUND AND OBJECTIVE: A diagnosis of periodontitis progression is presently limited to clinical parameters such as attachment loss and radiographic imaging. The aim of this multicenter study was to monitor disease progression in patients with chronic periodontitis during a 24-mo follow-up program and to evaluate the amount of bacteria in saliva and corresponding IgG titers in serum for determining the diagnostic usefulness of each in indicating disease progression and stability. MATERIAL AND METHODS: A total of 163 patients with chronic periodontitis who received trimonthly follow-up care were observed for 24 mo. The clinical parameters and salivary content of Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans were assessed using the modified Invader PLUS assay, and the corresponding serum IgG titers were measured using ELISA. The changes through 24 mo were analyzed using cut-off values calculated for each factor. One-way ANOVA or Fisher's exact test was used to perform between-group comparison for the data collected. Diagnostic values were calculated using Fisher's exact test. RESULTS: Of the 124 individuals who completed the 24-mo monitoring phase, 62 exhibited periodontitis progression, whereas 62 demonstrated stable disease. Seven patients withdrew because of acute periodontal abscess. The ratio of P. gingivalis to total bacteria and the combination of P. gingivalis counts and IgG titers against P. gingivalis were significantly related to the progression of periodontitis. The combination of P. gingivalis ratio and P. gingivalis IgG titers was significantly associated with the progression of periodontitis (p = 0.001, sensitivity = 0.339, specificity = 0.790). CONCLUSIONS: It is suggested that the combination of P. gingivalis ratio in saliva and serum IgG titers against P. gingivalis may be associated with the progression of periodontitis.

Effects of fatigue from sleep deprivation on experimental periodontitis in rats.

BACKGROUND AND OBJECTIVE: Factors such as vascularization of the periodontium, inflammatory reactions and immune response affect the oral environment and ecology, decreasing host resistance and promoting the development of symptoms and the advancement of periodontal disease. Fatigue also influences the hypothalamic-pituitary-adrenal axis and reports relate it to systemic resistance. The aim of this study was to evaluate whether fatigue is a modifying factor for periodontal disease in rats. MATERIAL AND METHODS: We divided 24 3-wk-old male Sprague-Dawley rats randomly into the following four groups: control; fatigue (deep sleep deprivation for 7 d); infection (rats inoculated with carboxymethyl cellulose containing periodontopathic bacteria); and compound (combined fatigue and infection conditions). Weight, serum corticosterone levels, serum albumin levels, interleukin-1ß and tumor necrosis factor-α expression levels and distance from the cement-enamel junction to the alveolar bone crest were measured at baseline, and on the 36th (before sleep deprivation), 43rd (immediately after sleep deprivation) and 57th d (end of experiment). RESULTS: Immediately after sleep deprivation and at the end of the experiment, weight gain in the fatigue and compound groups was significantly lower than in controls (p < 0.05). Immediately after sleep deprivation, serum corticosterone levels were significantly higher in the fatigue and compound groups than in controls (p < 0.05). Moreover, serum albumin levels were significantly lower in the fatigue and compound groups than in controls (p < 0.05). Immediately after sleep deprivation, gene expression of interleukin-1ß was significantly higher in the infection and compound groups than in controls (p < 0.05). Moreover, gene expression of tumor necrosis factor-α was significantly higher in the compound group than in controls (p < 0.05). At the end of the experiment, the distance from the cement-enamel junction to the alveolar bone crest was significantly higher in the infection and compound groups than in controls (p < 0.05). Moreover, the distance was significantly higher in the compound group than in the infection group. CONCLUSIONS: Fatigue worsened systemic health in rats and increased gingival inflammation and alveolar bone loss in experimental periodontitis. In conclusion, our results suggest that fatigue is a modifying factor for periodontal disease in rats.

Assessment of the plasma/serum IgG test to screen for periodontitis.

Chronic periodontitis is a silent infectious disease prevalent worldwide and affects lifestyle-related diseases. Therefore, efficient screening of patients is essential for general health. This study was performed to evaluate prospectively the diagnostic utility of a blood IgG antibody titer test against periodontal pathogens. Oral examination was performed, and IgG titers against periodontal pathogens were measured by ELISA in 1,387 individuals. The cut-off value of the IgG titer was determined in receiver operating characteristic curve analysis, and changes in periodontal clinical parameters and IgG titers by periodontal treatment were evaluated. The relationships between IgG titers and severity of periodontitis were analyzed. The best cut-off value of IgG titer against Porphyromonas gingivalis for screening periodontitis was 1.682. Both clinical parameters and IgG titers decreased significantly under periodontal treatment. IgG titers of periodontitis patients were significantly higher than those of healthy controls, especially in those with sites of probing pocket depth over 4 mm. Multiplied cut-off values were useful to select patients with severe periodontitis. A blood IgG antibody titer test for Porphyromonas gingivalis is useful to screen hitherto chronic periodontitis patients.

Nicotine-induced CCN2: from smoking to periodontal fibrosis.

Since fibrosis is observed in smokers' gingiva, it was hypothesized that fibrosis was caused by nicotine in the periodontium. Therefore, in this study, we investigated the effects of nicotine on the induction of a profibrotic molecule, connective tissue growth factor (CCN2/CTGF), in human gingival fibroblasts (HGFs) and periodontal ligament (PDL) cells. With 1 microg/mL nicotine, vacuolization and attenuated proliferation were observed. Interestingly, 1 microg/mL nicotine increased the production of CCN2/CTGF protein in both cells without increasing mRNA expression. Furthermore, type I collagen mRNA and protein were also increased and were significantly blocked by a CCN2/CTGF neutralizing antibody. This is the first report to describe a relationship between nicotine and CCN2/CTGF in periodontal tissue cells. Analysis of our data also indicated that nicotine was cytotoxic, while it increased CCN2/CTGF and, eventually, type I collagen production. These findings suggest that periodontal fibrosis can be promoted by nicotine from smoking via effects on CCN2/CTGF.

Genetic risk factors for periodontitis in a Japanese population.

Genetic variants at multiple loci have been shown to be associated with susceptibility to periodontitis. To better assess the genetic risk factors for periodontitis, we performed a case-control study in 319 Japanese individuals with periodontitis (172 aggressive and 147 chronic disease) and 303 race-matched healthy control individuals. Thirty-five functional gene polymorphisms that had been previously associated with immune responses were genotyped. For all gene polymorphisms tested, no significant differences were observed in the allele frequencies of persons with aggressive, chronic, and combined (aggressive and chronic) periodontitis, compared with control individuals. Multiple logistic regression analysis revealed a significant association of the vitamin D receptor +1056 T/C polymorphism with susceptibility to chronic periodontitis, after adjustment for age, gender, and smoking status (P = 0.002). These results suggest that none of the polymorphisms tested was strongly associated with periodontitis in a Japanese population. However, the vitamin D receptor +1056 polymorphism may be related to chronic periodontitis.

Effect of transforming growth factor-beta1 on expression of the connective tissue growth factor (CCN2/CTGF) gene in normal human gingival fibroblasts and periodontal ligament cells.

BACKGROUND AND OBJECTIVE: Connective tissue growth factor (CCN2/CTGF) plays an important role in wound healing and regulation of the extracellular matrix in periodontal tissue. However, the functional relationship between altered transforming growth factor-beta1 levels and CCN2/CTGF has not been extensively investigated in human gingival fibroblasts and periodontal ligament cells. This study investigated the effects of transforming growth factor-beta1 on the expression of the CCN2/CTGF gene in human gingival fibroblasts and periodontal ligament cells in vitro. MATERIAL AND METHODS: Cells were isolated from normal periodontal tissues and cultured in Dulbecco's modified Eagle's minimal essential medium/F12 containing 10% fetal bovine serum. Subconfluent cells were maintained under serum deprivation for 24 h then treated with Dulbecco's modified Eagle's minimal essential medium/F12 containing 0.5% fetal bovine serum (control) and 0.1, 1, 5 or 10 ng/mL of transforming growth factor-beta1 for 24, 48 or 72 h. The effects of transforming growth factor-beta1 on CCN2/CTGF mRNA expression were measured by reverse transcription-polymerase chain reaction. CCN2/CTGF protein was quantitatively analyzed using enzyme-liked immunosorbent assay. Subcellular distribution of CCN2/CTGF protein in both human gingival fibroblasts and periodontal ligament cells was observed using immunofluorescence microscopy. RESULTS: In both human gingival fibroblasts and periodontal ligament cells, the expression of CCN2/CTGF mRNA and CCN2/CTGF protein was significantly increased, in a dose- and time-dependent manner, in the presence of transforming growth factor-beta1. Moreover, immunofluorescence analysis indicated that immunoreactivity to CCN2/CTGF showed a granular pattern of protein localization. CONCLUSION: The expression of CCN2/CTGF mRNA and protein was induced by transforming growth factor-beta1 in human gingival fibroblasts and periodontal ligament cells. These results suggest that CCN2/CTGF plays an important role in wound healing and in the regeneration of periodontal tissue.

Comparative analysis of putative periodontopathic bacteria by multiplex polymerase chain reaction.

BACKGROUND AND OBJECTIVE: The polymerase chain reaction (PCR) has been applied for the rapid and specific detection of periodontopathic bacteria in subgingival plaque and is potentially of clinical benefit in the diagnosis and treatment of periodontitis subjects. However, several technical points need to be modified before the conventional PCR detection system can be used by clinicians. MATERIAL AND METHODS: To develop a PCR-based technique more applicable for clinical use than conventional PCR, we established a multiplex PCR for five putative periodontopathic (Treponema denticola, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Tannerella forsythia) and two nonperiodontopathic (Streptococcus sanguinis and Streptococcus salivarius) species of bacteria using whole-plaque suspension as templates, and detected bacteria in subgingival plaque taken from 85 subjects at the supportive periodontal therapy stage after active periodontal treatments. RESULTS: Among putative periodontopathic bacteria, the detection frequency of T. denticola and P. gingivalis was elevated in parallel with higher probing pocket depth and clinical attachment loss, and had 4.2-14.1 times increasing odds of the clinical parameters tested. Detection of any of the five species of putative periodontopathic bacteria markedly increased the odds ratio of a higher probing pocket depth, clinical attachment loss and bleeding on probing. CONCLUSION: The multiplex PCR system developed in this study enabled the detection of all the bacteria under investigation in one reaction tube in a less time- and labor-intensive manner than conventional PCR. These results support the potential clinical use of multiplex PCR for detecting periodontopathic bacteria and for evaluating therapeutic strategies and predicting the prognosis for each subject.

Effect of gamma-immunoglobulin on the asaccharolytic growth of Porphyromonas gingivalis.

BACKGROUND AND OBJECTIVES: A minimal medium is indispensable for examining the growth properties of the asaccharolytic bacterium, Porphyromonas gingivalis. The purpose of the present study was to improve the widely used KGB medium to support good growth of P. gingivalis. MATERIAL AND METHODS: Growth of P. gingivalis (W50, W83, and ATCC33277) in a minimal medium was monitored by measuring the optical density of the culture during incubation. RESULTS: W50, W83, and ATCC33277 grew poorly with bovine serum albumin as the sole carbon and nitrogen source, and alpha-ketoglutarate had little or no effect on this poor growth. In contrast, FeCl3 improved the growth of W83 and ATCC33277; however, the use of a high concentration of FeCl3 elicited black pigmentation of the cells. Bovine gamma-immunoglobulin greatly recovered the growth defect. None of alpha-ketoglutarate, citrate, or trace metal ions, when used to supplement KGB medium, was required for growth. We determined the optimal conditions for growth, and developed a new simple minimal medium for P. gingivalis (GA medium). Growth of ATCC33277 in GA medium was dependent on gingipains; Arg-gingipains and Lys-gingipain contributed comparably to proliferation of the bacterium. CONCLUSION: These data indicate that GA medium is currently the most reliable minimal medium for examining the growth properties of P. gingivalis.

Phagocytic function of salivary PMN after smoking or secondary smoking.

Alterations in polymorphonuclear leukocyte (PMN) functions, such as phagocytosis, chemotaxis, and oxidative burst, play a pivotal role in periodontal pathogenesis. In addition, previous studies have demonstrated a strong relationship between smoking and periodontal disease. In the present study, the effect of cigarette smoking or passive smoking (secondary smoking) on the phagocytic function of salivary PMN (SPMN) was investigated. Twenty volunteers with clinically healthy gingiva (10 smokers, 10 non-smokers) participated in this study. In a small room, the smokers and passive smokers (non-smokers) were instructed to smoke and breathe, respectively, in an identical, specific way for about 4 minutes. SPMN was isolated immediately before and after smoking or passive smoking. PMN was then incubated with fluoresbrite beads for 45 minutes at 37 degrees C and the phagocytic status estimated by using a flow cytometer. Cell viability was determined by trypan blue exclusion (smokers before smoking: 88.3%: smokers after smoking: 89.6%: non-smokers before passive smoking: 89.0%; non-smokers after passive smoking: 89.4%). In both smokers and passive smokers, the proportion of phagocytic cells increased between before and after smoking (smokers before: 33.2%; after: 42.1%: passive smokers before: 36.2%: after: 44.1%). Both increases were statistically significant (P < 0.01). These results demonstrate that the phagocytic activity of SPMN intensifies after smoking and passive smoking. They also suggest that certain substances in cigarette smoke, perhaps nicotine, overstimulate the host response in the oral cavity.

Longitudinal evaluation of elastase as a marker for the progression of periodontitis.

To determine whether elastase levels in gingival crevicular fluid (GCF) could serve as a marker for the progression of periodontitis, we monitored GCF elastase and periodontal status in selected sites in 32 periodontally healthy volunteers and 31 periodontitis patients at intervals over a 6-month period. Clinical measurements included plaque index, gingival index, bleeding on probing, suppuration, probing depth, clinical attachment level, and relative attachment level measured with an automated disk probe. GCF elastase, detected by reaction with a fluorescent substrate, was assessed visually against fluorescence standards and quantitatively with a fluorometer. Bone loss was detected by subtraction radiography of standardized vertical bite-wing radiographs at baseline and 6 months. Mean visual elastase scores (VES) and quantitative elastase measurements were significantly higher (P < 0.001) in sites from periodontitis patients than in sites from healthy volunteers. When bone loss was used as the criterion for disease progression, significantly higher (P < 0.001) visual and quantitative GCF elastase levels were found at progressing sites than in nonprogressing sites in the periodontitis patients. The odds ratios (OR) for the event of developing bone loss with positive 4-minute and 8-minute VES tests were 4.2 (P < 0.001) and 7.4 (P < 0.001), respectively. When corrected for the tendency of progressing sites to be clustered within a subpopulation of patients, the OR for developing bone loss with the 4-minute and 8-minute VES tests were 3.1 (P < 0.007) and 4.9 (P < 0.001), respectively. These data indicate that sites with high levels of elastase are at significantly greater risk for progressive bone loss as assessed by digital subtraction radiography.

Epithelial cell kinetics with atelocollagen membranes: a study in rats.

A recent development in guided tissue regeneration procedures is the use of resorbable membranes, which eliminate the need for subsequent surgical removal. In this study we performed flap surgery in rats with (experimental) or without (control) implantation of one of the newer materials, atelocollagen. We observed the gingival epithelial cell kinetics using 3H-thymidine and examined the extent of gingival epithelium migration. Histological observations at day 1 on the experimental side demonstrated regenerated epithelium apposed to the collagen membrane with an intervening layer of necrotic tissues and/or fibrinous exudate. There was no observable proliferation of regenerated epithelium toward the root apex. On day 14, the regenerated epithelium migrated apically along the treated root surface in the control group. By contrast, on day 14 in the experimental group, the regenerated epithelium contacted the root surface at the cemento-enamel junction (CEJ). Apical to the CEJ, there was new cementum formation with inserting connective tissue fibers. Autoradiographs from day 1 experimental sides demonstrated labeled cells in the basal cell layers from oral, crevicular, and junctional epithelium. From day 1 to day 5, labeling indices of oral epithelium and regenerating crevicular epithelium on experimental sides were lower than on control sides. These histological and autoradiographic findings suggest that atelocollagen membrane inhibits apical migration of regenerating epithelium and accelerates connective tissue reattachment in part by inhibiting the mitotic function of basal epithelial cells in early stages of wound healing.

[Clinical evaluation of ACDEMIN in the field of dentistry].

A clinical trial was performed to examine the effect of ACDEMIN, a combination of lysozyme chloride and vitamins (manufactured by Grelan Pharmaceutical Co., Ltd.,; supplied by Takeda Chemical Industries, Ltd.). The subjects were 65 patients with slight to moderate symptoms associated with locally developed diseases including gingivitis, periodontitis, pericoronitis of the wisdom tooth and gingival abscess. Improvement of the condition was evaluated according to symptom on the basis of local findings examined prior to and 7 days after administration. Adverse effects were also evaluated in terms of discomfort. General improvement was determined on the basis of improvement in symptoms and general safety on the basis of a comprehensive assessment of the adverse effects. The usefulness of the drug was determined on the basis of general improvement and general safety as assessed above. The results were as follows: 1) Of the 65 patients who entered the trial, 62 completed the course of administration. 2) The rates of improvement ("slightly improved" or better) according to symptom were 65.6% for gingival inflammation, 40.0% for bleeding, 50.0% for pus discharge, 41.8% for swelling, 61.9% for local pain, 26.7% for mouth odor, 21.7% for color tone and 62.3% for discomfort. 3) The rates of usefulness ("slightly useful" or better) according to disease were 66.7% for gingivitis, 92.0% for periodontitis, 81.8% for pericoronitis of the wisdom tooth and 100.0% for gingival abscess. 4) The usefulness of the drug was graded "very useful" in 4 patients, "fairly useful" in 18, "slightly useful" in 31 and "not useful" in none, with an overall rate of usefulness of 85.5% ("faily useful" or better). 5) No patients presented symptoms indicating an adverse effect.

[Examination of periodontal disease with gingival crevicular fluid. Correlation between capacitance and clinical findings].

An intimate relationship between the inflammatory state of the gingiva and the amount of gingival crevicular fluid (GCF) is well known. For the measurement of the volume of GCF, filter paper has been used in the past. In the present study, an electrostatic capacity measuring apparatus with sensor that is insertable into gingival sulcus was fabricated. Capacitance of GCF was measured in patients with periodontitis and the following results were obtained. 1. The measuring apparatus was controlled by a personal computer to obtain the data every 0.1 second. As the GI increased at the site of measurement, higher values were obtained, with longer persistence of the trend of increase in the measured value. 2. In view of the stability of the measured values, the amount of GCF appeared to be best expressed as the value obtained after 10 seconds. 3. The correlation between the capacitance and the clinical findings was evaluated at 500 sites. The correlation was the highest in GI followed by P1I, GBI and PD, suggesting the utility of this method in the detection of initial gingival inflammation.

[Application of local drug delivery system to periodontal therapy. 4. Comparison of the therapeutic effects of administration of a TC film or root debridement on human periodontal disease].

In 8 patients with periodontal diseases under good supragingival plaque control, 22 test teeth each having a pocket not more than 4 mm deep were treated respectively with 3 consecutive administrations of tetracycline immobilized cross-linked collagen film (TC film) at intervals of 1 week, with onceroot planing and with both of these. The therapeutic effects were compared both clinically and micro biologically. The results revealed improvements in clinical symptoms such as reduction in the depth of the pocket, bleeding on pocket probing and the like for each treatment group in 6-12 weeks. The second and third groups also showed remarked gingival recession. Further more, the density of intrapocket microorganisms showed a remarked decrease up to the 8th week for each treatment group and the population of spirochetes showed a decrease up to the 6th week for the first treatment group and up to the 8th-12th week for the second and third treatment group. The results show that both local application of the TC film and root planing are effective in periodontal treatment, but not the combined treatment.