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Background; In a previous study, we evaluated the in vivo effects of an Nd:YAG laser on periodontal disease by measuring crevicular interleukin (IL)-1β levels before and after laser application. It was found that laser therapy was less effective than traditional scaling and root planing. These results might be due to incomplete removal of microbial residues and cementum-bound endotoxin on root surfaces by the laser. In this study, we explored the in vitro effectiveness of an Nd:YAG laser for the elimination of cementum-bound endotoxin by measuring IL-1β changes in stimulated monocytes. Methods: Fresh human monocytes were harvested from adults without periodontitis and grown in RPMI 1640 medium. Diseased cementum particles were collected and prepared from teeth with untreated periodontitis and were irradiated with 5 levels of laser energy. Cementum particles were subjected to endotoxin testing by a limulus amebocyte lysate (LAL) assay and then were incubated with cultured monocytes. Production of IL-1β in stimulated monocytes was measured by enzyme-linked immunosorbent assay and quantified by spectrophotometry. Results: The endotoxin unit (EU) of diseased cementum was 18.4 EU/mg, which seemed to be remarkably lower than that of common periodontal pathogens including Porphyromanas gingivalis (381) at 15,300 EU/mg/ml, Prevotella intermedia (ATCC 25611) at 227 EU/mg/ml, and Fusobacterium nucleatum (ATCC 25586) at 1,967 EU/mg/ml. Monocytes subjected to stimulation by diseased cementum particles without laser irradiation produced 124 to 145 pg/ml IL-1β 9- to 18-fold higher than that of unstimulated monocytes (7.07 to 15.95 pg/ml). Diseased cementum particles after irradiation with various energy levels of the Nd:YAG laser could still stimulate monocytes to secrete 89 to 129 pg/ml IL-1β. No statistically significant difference was found in the production of IL-1β induced by diseased-bound cementum with or without laser irradiation. Conclusions: The Nd:YAG laser varying from 50 mJ, 10 pps to 150 mJ, 20 pps, for 2 minutes, did not seem to be effective in destroying diseased cementum endotoxin. [ABSTRACT FROM AUTHOR]

Background The Nd:YAG laser has recently been used in the treatment of periodontal disease. However, although a clinical reduction of probing depth and gingival inflammation to this new approach has been reported, it has not been fully evaluated. Interleukin-1 beta (IL-1β), a potent stimulator of bone resorption, has been identified in gingival crevicular fluid (GCF), which is closely associated with periodontal destruction. The aim of this study was to compare the effects of Nd:YAQ laser treatment versus scaling/root planing (SRP) treatment on crevicular IL-1β levels in 52 sampled sites obtained from 8 periodontitis patients. Methods: One or 2 periodontitis-affected sites with a 4 to 6 mm probing depth and horizontal bone loss from 3 adjacent single-root teeth in each of 4 separate quadrants were selected from patients for clinical documentation and IL-1β assay. Sampling site(s) from each diseased quadrant was randomly assigned to one of the following groups: 1) subgingival laser treatment (20 pps, 150 mJ) only; 2) SRP only; 3) laser treatment first, followed by SRP 6 weeks later; or 4) SRP first, followed by laser therapy 6 weeks later. The GCF was collected and the amount of IL-1β was assayed by enzyme-linked immunosorbent assay (ELISA). Clinical parameters and GCF were measured at baseline and biweekly after therapy for 12 weeks. Results: An obvious clinical improvement (marked decrease in the number of diseased sites with gingival index ≥2) and reduction of crevicular 1L-1β were found in all groups. The level of IL-1β was significantly lower in the SRP group (P = 0.035) than in the laser therapy group for the duration of the 12 weeks. The laser combined SRP therapy group showed a further reduction of IL-1β (6 to 12 weeks after treatment) than either laser therapy alone or SRP combined laser therapy. Conclusions: Our data suggest that laser therapy appeared to be less effective than traditional SRP treatment. Of the 4 treatment modalities, inclusion of SRP was found to have a superior IL-1β response, when compared to other therapies without it. In addition, no additional benefit was found when laser treatment was used secondary to traditional SRP therapy. [ABSTRACT FROM AUTHOR]

Background: Whether adjunctive tetracycline fibers can provide an additive effect to scaling and root planing in treating non-responsive sites in maintenance subjects is still controversial. Recolonization of the bacteria from untreated sites or from the extracrevicular region may explain the insignificant response to local therapy. The purpose of the present study was to evaluate the microbiological response of sites treated with tetracycline fibers combined with scaling and root planing. Methods: The study was conducted in a split-mouth design. Thirty patients on maintenance therapy having at least 2 non-adjacent sites in separate quadrants with probing depths between 4 to 8 mm with bleeding on probing, or aspartate aminotransferase enzyme levels > 300 µIU in the gingival crevicular fluid, were treated with scaling and root planing plus tetracycline fibers or with scaling and root planing only. Subgingival plaque samples were collected at baseline, end 1, 3, and 6 months following treatment. A. actino-mycetemcomitans, C. rectus, B. forsythus, E. corrodens, F. nucleatum, P gingivalis, and P. intermedia were detected by culture, immunofluorescence, or PCR technique. Results: There was a reduction of total bacterial cell count, as well as of certain periodontal pathogens, following treatment. The prevalence of A. actinomycetemcomitans, B. forsythus, and P. gingivalis and the mean proportions of C. rectus, P. intermedia, F. nucleatum, and P. gingivalis decreased after therapy, but there was no statistically significant difference between the 2 treatment groups with respect to bacterial proportions or the number of positive sites. Besides, the pathogens could not be eliminated from the periodontal pocket, and recolonization of the pocket was noted at 3 months post-treatment. Conclusions: Bacteria located within the cheek, tongue mucosa, saliva, or untreated sites may contribute to reinfection of the pockets and explain the insignificant response to local tetracycline therapy. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to evaluate the association between the occurrence of certain specific periodontal pathogens and aspartate aminotransferase (AST) levels in gingival crevicular fluid (GCF). Methods: Thirty systemically healthy subjects with moderate to advanced periodontitis were selected. Within each subject, the AST contents of GCF from sites with probing depth between 5 mm and 7 mm were measured using a chairside colorimetric test. AST-positive site refers to one that had an AST level ≥800 µIU. Subgingival plaque samples from one AST-positive and one negative site were collected for microbiological examination. One site with probing depth ≥3 mm and no gingival inflammation was selected as a healthy control. Clinical parameters of the chosen sites, including the plaque index and gingival index scores, probing depth, and clinical attachment level were measured. Culture and immunofluorescence (IF) were used for detecting common periodontal pathogens, including Actinobacillus actinomycetemcomitans, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Capnocytophaga species, Prevotella intermedia, Prevotella melaninogenica, and Porphyromonas gingivalis. Logistic regression was used to analyze the correlation between the AST test and certain specific pathogens. Results: The GCF scores and total cultivable bacterial counts were higher in AST-positive sites than either AST-negative or healthy sites The prevalence and proportions of specific periodontal pathogens such as C. rectus. E. corrodens, F. nucleatum. Capnocytophaga species, P. intermedia, and P. gingivalis were significantly higher in positive than in negative sites. In analyzing the correlation of the proportion of 6 pathogens with the AST test by logistic regression, only P. gingivalis showed a significant positive correlation. The odds ratio of having a high proportion of P. gingivalis in the presence of a positive AST test was 1.21. Conclusions: The present study showed that at AST-positive sites, there is a higher prevalence and higher proportion of certain periodontal pathogens. Although only the correlation of P. gingivalis and AST values was statistically significant, the results imply that certain periodontal pathogens may be associated with elevation of AST levels in GCF. [ABSTRACT FROM AUTHOR]