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Biomedical subjects

M R Patters

Publications and source records attributed to M R Patters.

At least 19 recordsLinked to original sources
PubMed2000

The prevalence of pathogenic periodontal microflora in healthy young adult smokers.

BACKGROUND: Smoking is a major risk factor in periodontitis, although the mechanisms of its effects are not well understood. The overall goal of this clinical study was to determine if smoking enhances the colonization of the oral cavity by pathogenic bacteria in a periodontitis-free population. The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, Bacteroides forsythus, and Treponema denticola was investigated in 25 smokers and 25 non-smokers by using DNA probes. METHODS: The subjects were 21 to 35 years of age with a healthy periodontium or slight gingivitis and were systemically healthy. The test group included subjects who had a minimum of a 1.5 pack-year history of smoking, while the control subjects never smoked. Subgingival plaque samples were taken by paper point following the assessment of multiple clinical parameters. RESULTS: This investigation showed: 1) no statistically significant differences were noted in any clinical parameter measured between the groups; 2) of the 8 subjects who were infected by at least 1 tested pathogen, seven were smokers (P= 0.02); 3) infected smokers had a 15.7+/-3.5 pack-year history and smoked a mean of 27+/-5 cigarettes/day versus 4.4+/-0.8 pack years and 15+/-1 cigarettes/day for the non-infected smokers (P = 0.0001 and P = 0.004); and 4) smokers were 18 times more likely to exhibit the presence of pathogens than non-smokers. CONCLUSIONS: These data indicate that the prevalence of colonization of the sulcus by pathogenic bacterial species in periodontitis-free individuals is related to the quantity and duration of cigarette smoking.

Adult↗
PubMed1998

The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus in humans 1 year after 4 randomized treatment modalities.

The relationship between probing attachment changes in treated periodontal pockets and the prevalence of selected periodontal pathogens was assessed in 10 patients with adult periodontitis 1 year following randomized therapy. All patients had at least 1 tooth in each quadrant with an inflamed pocket of probing depth > or =5 mm and clinical attachment loss and harbored at least one of the following 3 major periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, or Bacteroides forsythus. The number of target organisms per site was determined preoperatively; at 1 week; and at 1, 3, 6, and 12 months postoperatively utilizing DNA probes. The following clinical parameters were measured and recorded preoperatively and at 1, 3, 6, and 12 months post-treatment: gingival fluid flow, gingival index, plaque index, probing depth, probing attachment level, gingival recession, and bleeding on probing. One quadrant in each patient was randomly assigned to 1 of the following 4 treatments: 1) scaling and root planing; 2) pocket reduction through osseous surgery and apically-positioned flap; 3) modified Widman flap; and 4) modified Widman flap and topical application of saturated citric acid at pH 1 for 3 minutes. All 4 treatments were rendered in one appointment using local anesthesia. No postoperative antibiotics were used, but patients rinsed with 0.12% chlorhexidine for the first 3 months postoperatively and received a prophylaxis every 3 months. This investigation revealed: 1) 30.0% of the sites were infected by at least 1 species at 3, 6, and 12 months postoperatively. 2) Failing sites were infected by a high number of both Pg and Bf These sites had a mean of 24.2+/-9.0 x 10(3) Pg and 93.1+/-42.0 X 10(3) Bf while stable sites had a mean of 6.8+/-0.5 x 10(3) Pg and 7.2+/-1.2 x 10(3) Bf (P = 0.06 and P = 0.05, respectively). 3) The infected sites lost significantly more mean clinical attachment at 12 months (1.5+/-0.5 mm compared to a loss of 0.2+/-0.3 mm for uninfected sites, P = 0.017). 4) The infected sites had a significantly greater BOP (67+/-14% versus 25+/-8% for uninfected sites at 12 months, P = 0.012). 5) The choice of treatment modality did not affect the prevalence of the target species at 1 year post-treatment. These results suggest that prevalence of microbial pathogens negatively affects the 1 year outcome of periodontal surgical and nonsurgical therapy.

Adult↗
PubMed1997

The survival rate of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus following 4 randomized treatment modalities.

The overall goal of this clinical study was to determine the short-term anti-infective effects of four randomized treatment modalities on Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Bacteroides forsythus (Bf) and determine the effects of bacterial survival on treatment outcomes in patients with adult periodontitis. Twelve adult patients requiring therapy for moderate periodontitis were selected for this study. All patients had at least one tooth in each quadrant that had an inflamed pocket of probing depth > or =5 mm with probing attachment loss that harbored at least one of the following three periodontal pathogens: Aa, Pg, or Bf. The number of target organisms per site was determined pre-operatively, at 1 week, and 1 month and 3 months postoperatively utilizing DNA probes. One quadrant in each patient was randomly assigned to each one of the following four treatment groups: 1) scaling and root planing (SRP group); 2) pocket reduction through osseous surgery and apically-positioned flap (OS group); 3) modified Widman flap (MWF group); and 4) modified Widman flap and topical application of saturated citric acid at pH 1 for 3 minutes (CA group). The 4 treatment modalities were performed in one appointment. No postoperative antibiotics were used. Patients were instructed to supplement their daily oral hygiene with chlorohexidine oral rinse during the study. The results of this investigation indicated that: 1) none of the treatment modalities was effective in eliminating the target species; 2) the incidence of infected sites for all groups was 100% preoperatively; 62.5%, 33.3%, and 31.3% at 1 week, and 1 and 3 months postoperatively, respectively; 3) these infected sites lost 1.1 +/- 0.4 mm of probing attachment compared to gain of 0.0 +/- 0.3 mm for uninfected sites; 4) the infected sites had higher plaque and bleeding on probing 0.9 +/- 0.3, 73 +/- 12%, respectively, compared to 0.3 +/- 0.1 and 30 +/- 8% for the uninfected sites; and 5) no statistically significant differences were detected among the infected sites in regard to gingival index (1.0 +/- 0.2 vs. 0.8 +/- 0.1) or probing depth (3.5 +/- 0.4 vs. 3.0 +/- 0.1 mm). These results indicate that bacterial survival negatively affects the short-term clinical outcomes of non-surgical and surgical periodontal therapy.

Adult↗
PubMed1996

Repopulation of periodontal pockets by microbial pathogens in the absence of supportive therapy.

This clinical study evaluated the reinfection incidence by Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Prevotella intermedia (Pi) in periodontal pockets following scaling and root planing (SRP) and intra-pocket irrigation with antimicrobial agents in a patient population who did not receive supportive maintenance therapy. The number of target organisms was determined utilizing DNA probes. Forty-one (41) inflamed pockets > or = 5 mm with attachment loss and containing at least one target species were selected in 6 adult patients. Following a baseline clinical and bacterial examination, all patients received thorough SRP. In addition, 1 to 2 teeth in each patient were randomly assigned to each of the following 4 treatment modalities: 1) control group, no irrigation; 2) saline group, irrigation with 2 cc of 0.85% saline; 3) tetracycline group, irrigation with 2 cc of aqueous tetracycline HCl, 50 mg/ml (5%); and 4) chlorhexidine group, irrigation with 2 cc, respectively. All selected sites were non-adjacent. No additional therapy was rendered during the entire 1-year observation period. Clinical parameters and microbial analyses were recorded again at 1 week, and 1, 3, 6, 9, and 12 months post-treatment. The effect of antimicrobial irrigation on the reinfection rate of sites by Aa, Pg, and Pi was compared with that of the control groups (1 and 2) by ANOVA. No statistically significant differences were observed among the irrigation treatment groups with regard to any of the clinical or bacterial parameters studied. Therefore, the 4 treatment groups were combined into a single group whereby the rate of bacterial repopulation following extensive scaling and root planing could be ascertained. The infection incidence of sites at baseline (of total sites), 1 week and 12 months (of sites originally infected at baseline) was 14/41, 3/14, and 7/14 for Aa; 33/41, 6/33, and 12/33 for Pg; and 37/41, 3/37, and 12/37 for Pi, respectively. Thus, half or fewer of the originally infected sites became reinfected at 12 months despite lack of maintenance therapy. The results suggest that 1) a single episode of pocket irrigation with antimicrobial agents following thorough scaling and root planing did not affect the rate of repopulation of periodontal pockets by the tested pathogens; 2) thorough scaling and root planing has a lasting suppressive effect on selected periodontal pathogens for the majority of sites in patients with adult periodontitis; 3) pre-operative probing depth, the amount of gingival fluid flow and the composition of the subgingival microflora may serve as predictors for reinfection in the absence of maintenance care; and 4) reinfection of the treated sites by Aa, Pg, and/or Pi may constitute a risk factor that diminishes the effect of therapy in the absence of supportive maintenance care.

Adult↗
PubMed1994

DNA probe analyses of the survival of selected periodontal pathogens following scaling, root planing, and intra-pocket irrigation.

This clinical study evaluated the survival rates of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in periodontal pockets following scaling and root planing and intra-pocket irrigation with antimicrobial agents in patients with moderate and severe periodontitis. The number of target organisms was determined utilizing DNA probes. Adult periodontitis patients were selected on the basis that the subgingival flora contained at least one of the target organisms. Forty-eight (48) inflamed pockets > or = 5 mm in depth with probing attachment loss and containing at least one of the target species were then selected in 7 adult patients who harbored these bacteria. Following baseline clinical and bacterial examination, all patients received thorough scaling and root planing. In addition, 1 or 2 teeth in each patient which harbored the target flora at baseline were randomly assigned to each of the following 4 treatment modalities: 1) control group, no irrigation; 2) saline group, irrigation with 2 cc of physiologic saline; 3) tetracycline group, irrigation with 2 cc of aqueous tetracycline hydrochloride, 50 mg/ml (5%); and 4) chlorhexidine group, irrigation with 2 cc 0.12% chlorhexidine. All selected sites (5 to 8 per patient) were nonadjacent teeth. Clinical parameters and microbial analysis were recorded again at one week, and one month post-irrigation. The survival rate of the target microorganisms was determined and the effect of irrigation with antimicrobial agents on this microflora was compared with the control groups (1 and 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Assessment of complement cleavage in gingival fluid during experimental gingivitis in man.

The cleavage of complement may be an important immunopathologic mechanism in the development of gingival inflammation. Utilizing the experimental gingivitis model, cleavage of C3, C4 and B was assessed in gingival fluid following abstention from oral hygiene. 4 male dental students performed stringent oral hygiene measures until the gingival index approached 0, then refrained from any oral hygiene for 21 days. Gingival fluid, sampled with filter paper strips from the mesial surface of all maxillary premolars at 0, 7, 14, and 21 days, was assayed for C3, C4 and B cleavage by multilayer crossed-immunoelectrophoresis. Clinical indices were assessed following gingival fluid sampling. The subjects, who were plaque-free (PI = 0) at the beginning of the study, showed significant plaque accumulation at day 21 (87% of sites with PI greater than or equal to 2). Approximately 90% of the sites were free from clinical inflammation (GI = 0) at the start, but gingivitis increased with time such that 25% of the sites had GI scores of 2 at day 21. Bleeding on probing to the base of the pocket was not observed at day 0, but was observed at 62% of sites by day 21. Statistical analyses showed that all 3 indices significantly increased with time. The %C3 cleavage increased from a mean of 24% at day 0, to 35%, 45% and then 57% at days 7, 14 and 21, respectively, and both days 14 and 21 demonstrated significantly greater C3 conversion than that seen at day 0. The Spearman rank-order correlation coefficient for %C3 conversion versus time was p = 0.52, significant at the p less than 0.0001 level.(ABSTRACT TRUNCATED AT 250 WORDS)

Complement Activation↗
PubMed1985

Morphology of polymorphonuclear neutrophils during periodontal disease in the cynomolgus monkey.

The polymorphonuclear neutrophil (PMN) appears to be an important cell in the protection of the host from pathogenic periodontal micro-organisms. The purpose of the present histological studies was to observe the emigration of the PMN from the gingival vessels to the periodontal pocket during gingivitis and ligature-induced periodontitis in the cynomolgus monkey. 2 adult female monkeys were treated by application of a silk ligature around selected posterior teeth. After 9 weeks, the monkeys were perfused and block sections of both ligated (early periodontitis) and non-ligated (gingivitis) sites were obtained, cut into smaller blocks containing a single interdental area (N = 15 for periodontitis, N = 5 for gingivitis) and processed for light and electron microscopic observations. Morphologically, no differences in PMNs between gingivitis and periodontitis were observed and therefore the following description applies to both disease states. In the vessels, the endothelial cells appeared to be actively involved in PMN emigration, maintaining long processes which surrounded the PMNs. Within the connective tissue, the PMNs maintained their typical morphology which included polylobated nuclei and numerous lysosomal granules. Many intact PMNs were observed intercellularly within the connective tissue and the epithelium. Within the periodontal pocket, a multilayer of PMNs surrounded the plaque mass. Cells with numerous bacteria-containing phagolysosomes were observed with increasing frequency as they approached the plaque. Deeper within the bacterial deposit, PMNs were seen in varying stages of degeneration. These histologic studies, when interpreted in the light of reports of severe, rapidly-progressive periodontitis in patients with PMN disorders, suggest that the interaction of PMNs with bacterial plaque may serve to maintain a defensive boundary which protects the host tissues from irreversible destruction.

Animals↗
PubMed1983

The use of six selected teeth in population measures of periodontal status.

Selected teeth have been used to represent the entire dentition in many epidemiological and clinical investigations. The present study sought to assess the relationship between the six selected teeth described by Ramfjord and the entire dentition for the Plaque Index, Gingival Index, Calculus Index and Loss of Attachment. The computations were performed on measurements obtained in investigations of the natural history of periodontal disease in Norway and Sri Lanka. A consistently strong correlation was observed between the tooth subset and whole mouth for all indices in both populations. This relationship persisted even though single members or pairs of the subset of teeth were removed from the calculations. Some bias, however, was observed with all indices. Plaque and gingival indices obtained from the six teeth underestimated whole mouth scores in the low range (less than 1.0) and overestimated scores in the high range (greater than 2.0). Use of the tooth subset for calculus and loss of attachment consistently overestimated scores for the entire dentition.

Adolescent↗