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PubMed1989

[Effect of subgingival plaque control by direct irrigation technique--2. Clinical and microbiological changes after irrigation with acrinol or benzalkonium chloride solution].

The aim of the study was to evaluate the effect of the subgingival plaque control by direct irrigation. Twelve adult patients with periodontal pockets of 4 mm or more received an initial treatment. The patients were followed by irrigation using the device called Pocket Irrigator PT-01 with 0.05% acrinol solution or 0.025% benzalkonium chloride solution. The clinical and microbiological parameters were recorded prior to the irrigation and immediately after, at 1 hour, 1 day and 1 week after the irrigation. The Plaque Index, Gingival Index, gingival crevicular fluid and probing depth were used as clinical parameters. Samples of the subgingival plaque were collected with sterilized paper points from the periodontal pockets. The samples were examined by dark field microscopy with the Petroff-Hauser counting chamber with a magnification of 1,500x. The total number of bacteria and the proportion of the motile rods and spirochetes of the pockets were examined. All clinical parameters showed no significant changes after the irrigation. Intracrevicular irrigation by both acrinol and benzalkonium chloride solution significantly reduced the relative number of bacteria and the percentage of spirochetes/motile rods, when compared to those before the irrigation on day 1, though the differences did not persist on day 7. Thus, only by the single irrigation of the deep pockets with acrinol or benzalkonium chloride, the beneficial effects did not appear to continue clinically and microbiologically for a week.

Acridines↗
PubMed1994

The influence of surface-free energy on supra- and subgingival plaque microbiology. An in vivo study on implants.

The influence of surface free energy on supra- and subgingival plaque microbiology was examined in 9 patients with functional fixed prostheses supported by endosseous titanium implants. Two abutments (trans-mucosal part of the 2 stage implant) were replaced by either a new titanium abutment or a fluor-ethylene-propylene (FEP) coated abutment per subject. After 3 months of habitual oral hygiene, plaque samples were taken. Supragingival plaque was examined by means of differential phase-contrast microscopy, whereas for the subgingivial plaque additional analyses (DNA probes analysis, culturing) were performed. The subgingival samples were taken by paper-points and by scraping of the subgingival abutment surface. Differential phase-contrast microscopy showed a significant difference in plaque composition, especially when supragingival plaque was considered (P = 0.05). FEP coated abutments frequently harbored more coccoid microorganisms, whereas spirochetes or motile organisms were only detected around titanium abutments. Subgingivally, the number of colony forming units (CFU) in paper-points was comparable for both types of abutments. If the to-the-abutment-adhering plaque was considered, the number of CFU was 5 times higher on the titanium abutments than on the FEP coated abutments. However, this difference did not reach a statistical level of significance (P = 0.38). The DNA probe analysis of the subgingival plaque collected with paper-points showed a slightly higher frequency and concentration of perio-pathogens around the titanium abutments. However, the inter-substratum differences were smaller than the inter-subject differences. The latter seemed to be related to patient's dental status.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Adhesion↗
PubMed1982

Comparison of ultrasonic to hand instruments in the removal of subgingival plaque.

The primary objective of this study was to compare the effectiveness of hand and ultrasonic instrumentation in removing subgingival plaque. Twenty-four teeth in five patients were randomly assigned to be scaled by hand instruments, scaled by ultrasonic instruments, or uninstrumented as a control The subgingival tooth surface was delineated by a groove, and the teeth were then extracted for periodontal reasons. The percentage of plaque area relative to the total surface area of the side of the tooth was computed. No significant difference was found between the two methods in removing subgingival plaque. Furthermore, neither method removed all of the plaque.

Coloring Agents↗
PubMed1990

The survival of subgingival plaque bacteria in an amine fluoride-containing gel.

Subgingival plaque samples from 20 patients with chronic inflammatory periodontal disease were exposed to a commercial gel formulation containing 2 amine fluorides. The MIC of the gel for these samples ranged from 33 to 260 micrograms/ml with a modal value of 260 micrograms/ml. In each sample, the most resistant organisms (i.e., those organisms surviving at one doubling dilution below the MIC) were identified. 33 such organisms were isolated, of which 22 (67%) were strict anaerobes, and 25 (75%) were Gram negative. The 2 most frequent isolates were Bacteroides ruminicola ss. brevis and a Selenomonas species, neither of which is a recognised periodontopathogen. The gel had a rapid effect on the viability of the bacteria in the plaque samples, the 90% kill time being 17 min or less for 90% of the samples (range less than 5 to 71 min).

Adult↗
PubMed2000

The effects of sustained release doxycycline on the anaerobic flora and antibiotic-resistant patterns in subgingival plaque and saliva.

BACKGROUND: The purpose of this study was to determine the effects of periodontal treatment with a sustained-release, biodegradable gel containing 8.5% doxycycline on the anaerobic flora and on antibiotic susceptibility patterns associated with subgingival plaque and saliva. METHODS: Forty-five subjects with adult periodontitis were entered into a parallel design, single-blind study of 6 months' duration. The subjects were randomized to receive either doxycycline treatment (n = 23) or oral hygiene instruction/reinforcement (n = 22). Saliva and subgingival plaque samples were collected prior to and at 7, 21, 91, and 182 days after initiation of treatment. The proportion of the cultivable flora resistant to 10 microg doxycycline/ml was determined relative to total anaerobic counts, and the 3 most predominant colony types resistant to doxycycline were individually enumerated. A representative of each was subcultured, identified to genus and species level, and tested for its susceptibilities to 6 antibiotics. RESULTS: A significant decrease (P <0.01) in total anaerobic counts following doxycycline treatment caused a transient increase in the proportion, but not in the actual counts, of doxycycline-resistant bacteria recovered from both plaque and saliva at 7 and 21 days but not at 91 or 182 days. The same doxycycline-resistant taxa were recovered at all sample periods including baseline. Regardless of treatment, the isolates were similarly distributed and belonged to the same bacterial groups. CONCLUSIONS: Doxycycline treatment significantly reduced the anaerobic population in plaque but did not result in a change in either the number of resistant bacteria present or the acquisition of antibiotic resistance.

Adult↗
PubMed2005

Relationship of Actinobacillus actinomycetemcomitans serotypes to periodontal condition: prevalence and proportions in subgingival plaque.

No study available has utilized the new classification scheme (the consensus report of the American Academy of Periodontology 1999) to determine the prevalence of Actinobacillus actinomycetemcomitans in different periodontal conditions. The purpose of this study was to investigate prevalence and proportions of A. actinomycetemcomitans serotypes in subgingival plaque samples from a young Taiwanese population with aggressive periodontitis, chronic periodontitis and no periodontal disease. A total of 221 subgingival plaque samples from 171 diseased subjects (70 had aggressive periodontitis, and 101 had chronic periodontitis) (mean age 25.0 +/- 8.2 yr) and 50 periodontally healthy subjects (mean age 18.4 +/- 9.5 yr) were screened for A. actinomycetemcomitans. Serotypes of A. actinomycetemcomitans were determined by an indirect immunofluorescence assay using serotype-specific polyclonal antisera to A. actinomycetemcomitans strains ATCC 29523 (serotype a), ATCC 43728 (serotype b) and ATCC 33384 (serotype c). Prevalence (% of positive samples) of A. actinomycetemcomitans was 84.3% in aggressive periodontitis, 60.4% in chronic periodontitis, and 64.0% in periodontally healthy subjects. Proportions of A. actinomycetemcomitans (mean percentage per total bacteria) in periodontally healthy subjects were significantly lower than in aggressive periodontitis subjects. The proportion of serotype b in subjects with aggressive periodontitis and subjects with chronic periodontitis were significantly greater than that in periodontally healthy subjects. The proportion of serotype c in periodontally healthy subjects was much higher than that in chronic periodontitis subjects. The results of this study suggest that prevalence and proportions of A. actinomycetemcomitans are significantly greater in patients with aggressive periodontitis than in those with chronic periodontitis. Serotype b is the predominant serotype of A. actinomycetemcomitans in patients with diseased periodontal conditions. Serotype c is a more common serotype detected in periodontally healthy subjects.

Actinobacillus Infections↗
PubMed2002

Detection and quantification of oral treponemes in subgingival plaque by real-time PCR.

Oral treponemes have been associated with periodontal diseases. We developed a highly sensitive and specific method to detect and quantify cultivable oral treponemes (Treponema denticola, Treponema vincentii, and Treponema medium) in 50 subgingival plaque samples from 13 healthy subjects as well as 37 patients with periodontal diseases using real-time PCR assays with specific primers and a TaqMan probe for each 16S rRNA sequence. The specificity for each assay was examined by using DNA specimens from various treponemal and other bacterial species. The TaqMan real-time PCR was able to detect from 10(3) to 10(8) cells of the oral treponemes, with correlation coefficients as follows: T. denticola, 0.984; T. vincentii, 0.991; and T. medium, 0.984. The frequencies of occurrence of these three oral treponemes in subgingival plaque samples were as follows: T. denticola, 68.0%; T. vincentii, 36.0%; and T. medium, 48.0%. In addition, the number of T. denticola, T. vincentii, and T. medium cells in plaque samples detected by real-time PCR ranged from 3 to 15,184, 1 to 447, and 1 to 7,301 cells/pg of plaque DNA, respectively. Increased numbers of T. denticola cells were detected in plaque samples from deep periodontal pockets, and T. medium was also detected in deep pockets. On the other hand, T. vincentii was mainly found in shallow pockets. These results suggest that various oral treponemes are associated with the formation of each stage of periodontal disease.

Adolescent↗
PubMed1987

Differences in periodontal disease-associated microorganisms of subgingival plaque in prepubertal, pubertal and postpubertal children.

It is generally accepted that normal prepubertal children do not develop periodontitis, and that the severity of gingivitis in prepubertal children is usually less than that observed in children after puberty. One possible explanation is that the bacteria associated with periodontal diseases cannot become established in great numbers prior to puberty. Studies by Kornman and Loesche and others suggest that levels of black pigmented Bacteroides, especially B. intermedius, increase with increased levels of gonadotrophic hormones in pregnant women. Delaney and Kornman have found that there is a similar increase in levels of black pigmented Bacteroides with puberty. The present study involved cultural and microscopic characterization of the subgingival plaque flora of prepubertal, circumpubertal and postpubertal children with similar Silness and Löe plaque index scores. Puberty was confirmed through examination of wrist radiographs. Populations of black pigmented Bacteroides were very low in prepubescent children and were much higher in circumpubertal and postpubertal children. However, B. intermedius predominated only in circumpubertal plaques. Levels of total motile bacteria increased at each age level, but levels of spirochetes above 2% were observed only in the postpubertal group. These results support those of previous investigators who postulated a relationship between hormone levels and black pigmented Bacteroides levels in subgingival plaque and suggest that differences in the subgingival environment profoundly influence the proportions of suspected periodontopathic species in plaque.

Adolescent↗
PubMed2001

Mutans streptococci in subgingival plaque of treated and untreated patients with periodontitis.

BACKGROUND: The etiology of root caries is thought to be identical to coronal caries, though root caries seem to be more complicated because of the higher susceptibility of exposed roots (dentin) by periodontal therapy to demineralization than intact enamel. This implies that mutans streptococci are the most likely pathogens in the development of root caries. Although it is known that both the numbers of mutans streptococci and the frequency of isolation in root caries lesions are negatively correlated with the distance from the gingival margin, the subgingival sulcus has not been considered a possible habitat for mutans streptococci. However, subgingival occurrence of mutans streptococci in both untreated and treated periodontal patients has not been documented well in the literature. OBJECTIVE: To investigate the presence and levels of mutans streptococci in the subgingival plaque of patients (n=154) in different stages of periodontal therapy. The subgingival sulcus may be a possible habitat for mutans streptococci. This localisation of mutans streptococci may be of importance in the development of root caries after periodontal surgery. MATERIALS AND METHODS: In this cross-sectional study, subgingival plaque samples from 154 consecutive adult periodontitis patients were tested for presence and levels of mutans streptococci and putative periodontal pathogens by anaerobic cultures. These patients were divided into 4 groups based on their stage of periodontal treatment: (1) untreated patients; (2) patients after initial periodontal therapy only; (3) patients in the maintenance phase who not underwent periodontal surgery; (4) patients after periodontal surgery. RESULTS: The prevalence of mutans streptococci in the 4 study groups varied from 82% in untreated patients to 94% in maintenance patients. The mean proportion of mutans streptococci was 6.65% in maintenance patients versus 1.86% in untreated patients (p=0.005) and 2.51% in patients after scaling and root planing (p=0.041). CONCLUSIONS: The subgingival area is a microbial habitat for mutans streptococci that may be of importance in the development of root caries in periodontitis patients.

Adult↗
PubMed2000

PCR monitoring for tetracycline resistance genes in subgingival plaque following site-specific periodontal therapy. A preliminary report.

BACKGROUND: The selection of antibiotic resistance genes during antibiotic therapy is a critical problem complicated by the transmission of resistance genes to previously sensitive strains via conjugative plasmids and transposons and by the transfer of resistance genes between gram-positive and gram-negative bacteria. The purpose of this investigation was to monitor the presence of selected tetracycline resistance genes in subgingival plaque during site specific tetracycline fiber therapy in 10 patients with adult periodontitis. METHOD: The polymerase chain reaction (PCR) was used in separate tests for the presence of 3 tetracycline resistance genes (tetM, tetO and tetQ) in DNA purified from subgingival plaque samples. Samples were collected at baseline, i.e., immediately prior to treatment, and at 2 weeks, and 1, 3, and 6 months post-fiber placement. The baseline and 6-month samples were also subjected to DNA hybridization tests for the presence of 8 putative periodontal pathogenic bacteria. RESULTS: PCR analysis for the tetM resistance gene showed little or no change in 5 patients and a decrease in detectability in the remaining 5 patients over the 6 months following tetracycline fiber placement. The results for tetO and tetQ were variable showing either no change in detectability from baseline through the 6-month sampling interval or a slight increase in detectability over time in 4 of the 10 patients. DNA hybridization analysis showed reductions to unmeasurable levels of the putative periodontal pathogenic bacteria in all but 2 of the 10 patients. CONCLUSIONS: These results complement earlier studies of tet resistance and demonstrate the efficacy of PCR monitoring for the appearance of specific resistance genes during and after antibiotic therapy.

Adult↗
PubMed1986

The effects of a simplified mechanical oral hygiene regime plus supragingival irrigation with chlorhexidine or metronidazole on subgingival plaque.

23 patients with pockets greater than or equal to 4 mm and evidence of bone loss on radiographs received thorough scaling and root planing followed by instruction in Bass brushing. They refrained from routine interdental cleaning for the first 28 days. A pulsating jet irrigator was used once daily supragingivally with 0.02% chlorhexidine (CH) 0.05% metronidazole (MD) or 0.01% quinine sulphate inactive control (PL), on a randomized double blind basis. Molar sites were not irrigated and served as control sites; they were only mechanically cleaned. For each patient, subgingival plaque samples were obtained from 2 test and 1 control sites at baseline (day 0), and on days 7, 28, 56 and 84. Plaque samples were monitored by darkfield microscopy on the basis of morphological characteristics of 4 types of bacteria: cocci, motile cells, spirochaetes and "others" (nonmotile rods, filaments and fusiforms). The simplified oral hygiene regime of scaling, root planing and Bass toothbrushing combined with interdental supragingival pulsating jet irrigation with CH, MD or PL appeared superior to a system of simplified oral hygiene alone, particularly during the first 4 weeks. However, at most time-points, the benefits were not statistically significant except for metronidazole. By day 84, the end of the experimental period, all groups approximated baseline levels. The results indicate that supragingival pulsated jet irrigation has limited effects on the composition of subgingival plaque. More marked changes occur when the irrigation fluid contains a chemical agent such as metronidazole known to be effective against important subgingival organisms, but probably not to such an extent as to change the composition of the flora from one associated with diseased sites to one associated with healthy sites.

Adult↗
PubMed1980

Eruption of teeth into crowded position, loss of attachment, and downgrowth of subgingival plaque.

The role of crowded teeth in the etiology of attachment loss was studied in thirty teeth extracted for orthodontic reasons from eight children 12 to 13 years of age. Following extraction, the teeth were stained in a 1 percent solution of water blue and examined under the stereomicroscope. In one third of the thirty teeth, a 0.9, 2.0, and 3.5 mm. loss of attachment was observed on surfaces adjacent to which another tooth had erupted into an extremely crowded environment. On the same surfaces, subgingival plaque had grown down to the area of the cementoenamel junction. The premature loss of attachment was assumed to be mediated by collagenase derived from the regressing dental organ or from the junctional epithelium surrounding the erupting teeth. The premature downgrowth of subgingival plaque to the area of the cementoenamel junction was facilitated by the development of an irregular contact line within the interdental papilla, rather than a contact point above the papilla.

Adolescent↗
PubMed2000

Enumeration of Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans in subgingival plaque samples by a quantitative-competitive PCR method.

Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans are believed to play an important role in adult periodontitis, but the significance of their relative numbers and progress of the disease is still unclear. Traditional quantitative methods are generally time-consuming and inaccurate. The aim of this study was to develop a sensitive, quantitative PCR technique that would be useful for enumerating P. gingivalis, Pr. intermedia and A. actinomycetemcomitans in subgingival plaque samples from subjects with adult periodontitis. Primers to the following genes were employed: the fimbrial gene (fimA) of P. gingivalis, the 16S rRNA gene of Pr. intermedia and the leukotoxin-A (lktA) gene of A. actinomycetemcomitans. Competitive templates were constructed either by sequence deletion between primer binding sites or by annealing of the primer binding sites to an appropriate DNA core so as to yield products of a different size from that obtained with the target template. Coamplification of target and competitive templates yielded products of expected size and non-specific recognition by the primers was not found. The sensitivity of the designed primers was 100 cells of P. gingivalis, 100 cells of Pr. intermedia and 10 cells of A. actinomycetemcomitans. The three species were found in subgingival plaque samples collected from both healthy and diseased sites by the quantitative-competitive (QC)-PCR method and the technique was more sensitive than cultural methods. For determining the proportions of each of the three periodontopathogens, the total number of bacteria in the samples was enumerated by quantitative-PCR with 16S rRNA universal primers (27f and 342r). The findings indicate that QC-PCR is a useful method for enumerating bacteria in clinical oral specimens and the technique could play a role in the investigation of disease progression.

Actinobacillus Infections↗
PubMed1989

Black-pigmented Bacteroides species and Actinobacillus actinomycetemcomitans in subgingival plaque of adult Kenyans.

A microbiological study was performed of the subgingival plaque on 2 sites in each of 20 adults originating from a rural area 40 km outside Nairobi, Kenya. The recovery rate of B. gingivalis was 70%, of B. intermedius 100% and of A. actinomycetemcomitans 40% of the subjects, and 50%, 90% and 28%, respectively, of the sites. The isolated strains exhibited similar biochemical characteristics and antibiotic susceptibility pattern as type strains of these species. The high recovery rate of these 3 bacterial species in adult Kenyans was a rather surprising finding, since pathological pocketing was found only sporadically. Furthermore, the results of 2 methodological approaches tested demonstrated that such microbiological studies can be carried out in countries with limited laboratory facilities.

Actinobacillus↗
PubMed1993

Identification of Bacteroides forsythus in subgingival plaque from patients with advanced periodontitis.

Bacteroides forsythus has been associated with destructive adult periodontitis. Up to now, detailed analysis by classical means was hampered by the fastidious nature of the organism. There is hope that the application of molecular detection methods such as indirect immunofluorescence or in situ hybridization (ISH) will allow for more rapid and accurate identification. Here we describe a B. forsythus-specific probe (BFV530), complementary to 16S rRNA, which correctly identified all B. forsythus isolates as confirmed by biochemical, protein, or fatty acid analysis. To assess whether this probe might be suitable for direct identification of B. forsythus in clinical specimens, a total of 92 subgingival plaque samples were analyzed. Fifty-five specimens were tested in parallel by culture, light microscopy, and filter hybridization. Unfortunately, the overall agreement between results of filter hybridization and conventional methods was 70.9% only. We therefore examined 37 new specimens by ISH and indirect immunofluorescence by using fluorescently labeled probe BFV530 or B. forsythus-specific monoclonal antibody 116BF1.2 (kindly provided by R. Gmür, Zurich, Switzerland), respectively. Agreement between these methods was 100%, indicating that ISH with probe BFV530 might be used to accurately identify B. forsythus directly in subgingival plaque samples.

Adult↗
PubMed1983

Antibiotic susceptibility testing of subgingival plaque samples.

The in vitro inhibitory effect of several antimicrobial agents was determined against dispensed dental plaque samples taken from periodontally diseased sites as an aid in the selection of antibiotics for adjunctive use in periodontal therapy. 2 groups of patients were sampled. 1 group of 10 patients with severely advanced disease had received periodontal treatment which included the frequent adjunctive use of an antibiotic. The second group consisted of 15 individuals with less severe periodontal disease; only 4 individuals had been previously treated with antibiotics for their periodontal disease. Bacterial samples of subgingival plaque were taken from each patient and tested against a battery of antibiotics to determine which agent was the most effective in suppressing bacterial growth. Each antibiotic was incorporated into Trypticase-soy blood agar at a concentration equivalent to that achieved in either gingival fluid or blood following recommended oral dosages. The inhibitory effect was determined by comparing the number of bacterial recovered on the antibiotic-containing medium to the total number of bacteria recovered on the basal medium. Penicillins, with the exception of cloxacillin, were the most effective in inhibiting bacterial growth. Benzylpenicillin consistently inhibited the growth of 90% of the isolates recovered on media free of antibiotics while ampicillin and amoxicillin frequently inhibited 99% or more of the bacteria recovered. Tetracycline was generally inhibitory for at least 90% of the isolates if the patients had not been previously treated with this agent. However, resistance to this drug was common in samples taken from patients previously treated with tetracycline. Doxycycline, a tetracycline derivative, did not inhibit significantly more isolates than tetracycline. Clindamycin was inhibitory for 90% or more of the organisms in most of the samples; and, was usually effective in inhibiting isolates in samples which exhibited large numbers of isolates resistant to tetracycline. Erythromycin was relatively ineffective against the isolates recovered from samples from the severely diseased group but was inhibitory to isolates in some samples taken from the more moderately diseased group. Metronidazole, at the concentration tested, was largely ineffective against the isolates in bacterial samples from both groups. No single antimicrobial agent was found to be inhibitory for greater than 90% of the bacteria recovered from all of the subgingival plaque samples with the possible exception of some penicillins.

Adolescent↗
PubMed1998

Detection of Prevotella intermedia in subgingival plaque of adult periodontitis patients by polymerase chain reaction.

A PCR assay was developed that could specifically amplify DNA from the periodontal pathogen Prevotella intermedia. A pair of primers was selected from regions of the 16S rRNA gene of P. intermedia that were both divergent in sequence at their 3' ends with respect to the corresponding regions of the 16S rRNA gene of P. nigrescens, its most closely related species, and used in the PCR assay. Positivity was indicated by amplification of an 855 bp product. Using purified genomic DNA from these 2 species, assay conditions were determined under which only P. intermedia DNA and not P. nigrescens DNA was amplifiable. Absolute specificity of the assay was confirmed by the fact that no amplification products were obtained when using DNA from several other important periodontal organisms. The optimized PCR assay was used to identify P. intermedia in subgingival plaque samples of patients with adult periodontitis. Confirmation of amplification of P. intermedia DNA was achieved by digestion of PCR products with the restriction endonuclease RsaI, which gives different restriction patterns for P. intermedia and P. nigrescens. Of the 97 samples analysed, 38 (39%) were positive for P. intermedia. The results obtained confirm P. intermedia as a possible aetiological agent of adult periodontitis. Additionally, PCR primers targeting the corresponding region of the 16S rRNA gene of P. nigrescens were shown to be specific for the organism when used in a PCR assay, although P. nigrescens was not detectable in any of the subgingival plaques analysed.

Adult↗