Relationship between the percentage of subgingival spirochetes and the severity of periodontal disease

Effects on gingivitis of daily rinsing with 1.5% H2O2

The purpose of this study was to compare 2 groups of adolescents undergoing orthodontic treatment with fixed appliances to determine whether once daily use of a mouthrinse containing 1.5% H2O2 along with toothbrushing would be better than toothbrushing alone in maintaining their periodontal health. The 2 groups of subjects were selected non-randomly but were matched for age and sex. The control group (N = 34) used toothbrushing and a mint-flavored 0.05% NaF mouthrinse once daily, while the treatment group (N = 25) used toothbrushing and a once daily rinse with a preparation containing 0.05% NaF and 1.5% H2O2 (Orthoflur). 2 calibrated clinical examiners made single-blind clinical assessments of the plaque index, gingival index, and bleeding tendency in 6 standard sites per subject. They also noted any generalized mucosal irritations or staining of the teeth or tongue. Assessments were made before appliances were placed (baseline) and 1, 3, 6, 9, 12 and 18 months after appliances were placed. Results indicated that although there were no significant differences at baseline, the Orthoflur group had significantly fewer study sites with gingival indes or bleeding tendency scores greater than 1 than the control group from the 1-month through the 18-month examinations (P less than 0.01), and significantly fewer sites with plaque index greater than 1 and bleeding tendency scores of 2 or more from the 3-month through the 18-month examinations (P less than 0.02 and 0.01, respectively). No generalized mucosal irritations or clinically significant staining of the tongue or teeth were noted in either group during the study.

Effect of rotary electric toothbrush versus manual toothbrush on periodontal status during orthodontic treatment

Adolescents with fixed orthodontic appliances frequently have increased levels of plaque accumulation and gingivitis. The purpose of this study was to determine whether a rotary electric toothbrush would be more effective than conventional toothbrushing in maintaining periodontal health in these patients. Forty adolescent patients were divided into equal groups matched for sex and age. Before and during placement of orthodontic appliances, one group was instructed in use of the rotary electric toothbrush and the other in the use of a conventional toothbrush; these instructions were reinforced at monthly visits thereafter. Baseline clinical assessments of Plaque Index, Gingival Index, and bleeding tendency were made on six standard teeth before appliances were placed. assessments were repeated at 1, 3, 6, 9, 12, and 18 months after appliances were placed. Intragroup and intergroup differences were tested by a two-way analysis of variance. At baseline there were no significant differences between the two groups for any study variable. During the 18-month study period, however, plaque accumulation and gingivitis increased significantly over baseline levels in the control group (p less than 0.01) but remained stable in the group using the rotary electric toothbrush. In addition, the control group showed significantly greater plaque (p less than 0.01), gingival inflammation (p less than 0.001), and gingival bleeding on probing (p less than 0.001) than did the treatment group from the 1- to 18-month examinations. These data suggest that the rotary electric toothbrush is more effective than conventional toothbrushes for removing plaque and controlling gingivitis in adolescents during orthodontic treatment with fixed appliances.

Effects of adjunctive treatment of periodontitis with tetracycline and spiramycin

The present study was undertaken to compare the efficacy of two antibiotics, spiramycin and tetracycline, with a placebo when used adjunctively with scaling and root planing in the treatment of advanced adult chronic periodontitis. This was a double-blind, parallel, randomized trial with one factor (drug) at three levels. Ninety-six patients (mean age 46 +/- 1) were randomly assigned into one of three groups. All groups were scaled and root planed with each respective group receiving either spiramycin, tetracycline, or a placebo for 2 weeks. Two sites with probing depth of at least 7 mm were evaluated and the following clinical parameters were measured at baseline, 2, 8, 12, and 24 weeks: plaque index, bleeding on probing, crevicular fluid, probing depth, and change in the attachment level. The changes in the subgingival bacteria were monitored also using a differential staining technique. Seventy-nine patients completed the study. At the end of 24 weeks, although all three groups had shown clinical improvement when compared to the baseline data, there were no significant intergroup differences in any of the clinical parameters measured. While the proportion of spirochetes were significantly decreased (P less than 0.05) at 2- and 8-week intervals in both tetracycline and spiramycin groups (26% to 0.04% and 28% to 0.04%, respectively), compared to the placebo group (30% to 7%), only in the spiramycin group was the proportion of spirochetes significantly lower than the placebo group at the 24-week interval (3% and 11%, respectively). At week 24, the proportion of spirochetes in the tetracycline group had rebounded to 7%, which was not significantly different from the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal implications of orthodontic treatment in adults with reduced or normal periodontal tissues versus those of adolescents

This longitudinal study monitored periodontal status in 20 adults and 20 adolescents undergoing fixed orthodontic treatment. Ten adults had generalized periodontitis and received periodontal treatment, including periodontal surgery, before orthodontic treatment. They also received periodontal maintenance at 3-month intervals during orthodontic treatment. The other 10 adults had normal periodontal tissues. Neither these latter adults nor the adolescents received periodontal maintenance during orthodontic treatment. Periodontal status was determined (1) at six standard sites before fixed appliances were placed (baseline), (2) at 1, 3, 6, 9, 12, and 18 months after appliances had been placed, and (3) 1, 3, 6, and 12 months after appliances had been removed. At each of these visits, these sites were assessed for plaque index, gingival index, bleeding tendency, and pocket depth. Loss of attachment between baseline and 3 months after appliances were removed and tooth loss were also determined. Complete data were obtained for 15 adolescents and 14 adults. During orthodontic treatment the adolescent group showed significantly more (p less than 0.05) periodontal inflammation and supragingival plaque than the adults; after appliances were removed, this pattern was no longer statistically significant. For loss of attachment, there were no significant differences among adolescents, adults with normal periodontal tissues, or adults with reduced but healthy periodontal tissues who had undergone treatment for periodontal disease. For tooth loss, three nonstudy site teeth with pockets deeper than 6 mm and/or furcation involvements were lost because of periodontal abscesses in the adult group treated for periodontal disease.

Clinical effects of local application of collagen film-immobilized tetracycline

Tetracycline-containing cross-linked collagen film (TC film), or tetracycline-free placebo film, were locally applied 4 times, at 1-week intervals, to 33 teeth with periodontal pockets larger than 4 mm, in 11 patients with periodontal disease. The clinical and microbiological effects are summarized, as follows. In the group treated with the TC film, (1) the clinical indices were significantly decreased at the 4th and 7th weeks in comparison with those at the beginning of treatment. In particular, this group showed a significant decrease in the incidence of bleeding as compared with the placebo group at the 4th week. (2) Total counts of bacteria in the periodontal pockets showed an obvious tendency to decrease with time. The proportion of black-pigmented bacteroides was significantly decreased at the 4th and 7th weeks when compared with the pretreatment value. The extent of decrease in the proportion of spirochetes at both the 4th and 7th weeks was significant compared with the placebo group and the pretreatment value.

Synthesis and secretion of phospholipase C by oral spirochetes

Four strains of oral treponemes and Treponema phagedenis Reiter synthesize and secrete phospholipase C (PLC), which was detected by the hydrolysis of p-nitrophenylphosphorylcholine. PLC was detected in gingival crevicular fluid from diseased but not from healthy sulci. The initiation and progression of periodontal lesions may begin with the hydrolysis of membrane phospholipids by PLC.

The relationship between microbiological assays and the clinical signs of periodontal disease

Ninety-five patients with periodontal disease each had subgingival plaque samples collected from four sites (one from each quadrant) in their mouths. The relative proportions of spirochaetes, motile rods and cocci were determined using dark field microscopy and the proportion of anaerobic to aerobic micro-organisms calculated after culture. In addition, clinical recordings were made. The only significant correlations observed were between probing depth or attachment loss and the proportion of cocci in the plaque (negative association), probing depth or attachment loss and sites which were suppurating or displayed a radiolucent interdental crest (positive association), and the percentage of cocci and sites with a radiolucent interdental crest (negative association). Partial correlation analysis controlling for probing depth or attachment loss showed that a significant inverse association between the percentages of cocci and the presence of a radiolucent interdental crest remained. No significant associations were observed between clinical signs such as bleeding on probing or suppuration and the microbiological assays. Overall there was a poor correlation between many of the signs thought by some to indicate periodontal disease activity.

Four-year investigation of salt and peroxide regimen compared with conventional oral hygiene

This study of 171 subjects compared the effectiveness of a patient-applied salt and peroxide oral hygiene regimen with the use of conventional oral hygiene methods on clinical measures of periodontal disease, and determined patient compliance with and acceptance of using these two oral hygiene regimens. Results indicated that both regimens, when combined with professional care, were effective in changing clinical measures of periodontal disease to a state favoring periodontal health.

Dark-field microscopy of subgingival plaque microflora in Indian and English subjects

This present investigation reports on the microbial pattern of subgingival plaque from English and Indian subjects living in the West Midlands of England. Subgingival plaque from healthy and diseased sites was studied using darkfield microscopy. The results indicate that significant differences exist in microbial flora of clinically normal and diseased sites of English as well as Indian subjects. Coccoid cells predominated in healthy sites, with an increase of 21% in the spirochaetes in diseased sites. The ratio of non-motiles to motiles was 1:0.6 in healthy sites, whereas in diseased sites the ratio observed was 1:1.8 in English subjects and 1:3.6 in Indian subjects. Comparison of healthy sites in Indians with healthy sites in English subjects revealed significant differences between numbers of rods (p less than 0.05). Comparing diseased sites of Indians with diseased sites in English subjects revealed significant difference between both cocci (p less than 0.05) and motile rods (p less than 0.01). A positive correlation between chronic inflammatory periodontal disease and spirochaete burden, and a negative one between the disease and coccal burden, was found.

Isolation of a chymotrypsinlike enzyme from Treponema denticola

A chymotrypsinlike protease with an Mr of 95,000 was extracted from Treponema denticola ATCC 35405 and was partially purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The proteolytic activity was detected in an electrophoretogram containing polyacrylamide that was conjugated to bovine serum albumin. A single band of activity was detected when the T. denticola extract was solubilized and electrophoresed in the presence of sodium dodecyl sulfate. No activity was found in extracts of Treponema vincentii. The enzyme hydrolyzed transferrin, fibrinogen, alpha 1-antitrypsin, immunoglobulin A, immunoglobulin G, gelatin, bovine serum albumin, and a synthetic peptide containing phenylalanine. It did not degrade collagen or synthetic substrates containing arginine or proline. For the hydrolysis of azocoll, the pH optimum of the enzyme was 7.5. Heating at temperatures above 50 degrees C destroyed the activity. Reducing agents and the chelators EDTA and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid increased the enzyme activity, while phenylmethylsulfonyl fluoride, L-1-tosylamide-2-phenylethyl chloromethyl ketone, sulfhydryl reagents, and human serum reduced activity. The ability of the enzyme to hydrolyze a number of humoral proteins suggests that it may be involved in spirochete invasiveness and tissue destruction.

A rationale for monitoring the periodontal microbiota after periodontal treatment

Strict control of dental plaque accumulation remains the cornerstone of successful maintenance of the treated patient. However, some recurrences of periodontitis appear to take place despite good oral hygiene habits. A proportion of these are likely due to qualitative features of the periodontal microbiota rather than merely increased mass. Microscopic as well as cultural monitoring of qualitative features of the periodontal microbiota may be helpful in detecting critical changes. This review presents some of the research findings that provide a rationale for microbiological monitoring. Some of the advantages as well as difficulties encountered with these procedures are discussed.

Longitudinal study of untreated periodontitis (II). Microbiological findings

11 volunteer subjects with advanced chronic periodontitis participated in a 1-year longitudinal clinical and microbiological study. Subgingival plaque was collected at each of 7 visits from 148 pre-selected sites in the left jaw quadrants (test sites) and on the first and last visits, only from 117 sites in the left jaw quadrants (control sites). All sites were examined clinically at each of the 7 visits, and the microbiological markers investigated were the % spirochaetes and % black pigmented Bacteroides species in subgingival plaque. At the completion of the study, the sequential changes in probing attachment level at each site were subjected to regression analysis to determine the direction and extent of attachment change. Possible correlations between attachment change and % spirochaetes or % black-pigmented bacteroides were investigated using both individual sites and individual subjects. No significant differences were observed in either of the microbial variables between test and control sites. Possible correlations between the microbiological markers and attachment changes were investigated at baseline, at the 12-month visit and using the microbial data accumulated over all 7 visits. Significant differences were observed only at the 12-month visit when the % spirochaetes of both test and control sites were significantly lower in subjects showing the greatest improvement in attachment level. Overall, these results indicate that quantification of either spirochaetes or black-pigmented Bacteroides species cannot be used reliably to identify or predict disease-active sites.

Quantitative relationship of Treponema denticola to severity of periodontal disease

The Treponema denticola content of plaque was quantitatively estimated for samples taken from periodontitis patients as well as periodontally healthy subjects among two separate human populations. The populations studied included military volunteers and civilians at a university dental clinic. The plaque samples from each population were grouped according to pocket depth measurements at the collection site. A biotin-avidin enzyme-linked immunosorbent assay procedure was developed with a monoclonal antibody specific for a serovariety of T. denticola. T. denticola was present at significantly elevated levels in plaque samples collected from deep-pocket sites of patients with severe periodontitis relative to the healthy controls and a group with moderate disease. The ratio of T. denticola content per milligram of plaque in the deep pocket groups to that of the other two groups was about 2:1 for both populations. This is the first quantitative evidence of a positive relationship between a specific spirochete species and severe periodontitis.

Effects on gingivitis of two different 0.4% SnF2 gels

For nine months we monitored the periodontal health of 81 adolescents undergoing orthodontic treatment with fixed appliances, to determine whether daily use of a brush-on 0.4% SnF2 gel would be better than toothbrushing alone in maintaining periodontal health in these patients, and whether a gel supplying a high percentage of available Sn2+ ion would be more beneficial than a gel supplying a low percentage of available Sn2+ ion. The subjects were matched for age and sex and placed into a control group, which used toothbrushing alone, and two treatment groups, which used toothbrushing supplemented with daily use of a SnF2 gel. One treatment group used a gel with 98% available Sn2+ ion twice daily for the entire nine months. The other treatment group used a gel with less than 2% available Sn2+ once a day for six months, then twice a day for the remaining three months of the study. Clinical assessments (Plaque Index, Gingival Index, Bleeding Tendency, pocket depth, and coronal staining) were made before appliances were placed and at one, three, six, and nine months after appliances were placed. Results indicated that the group using the high-availability Sn2+ gel twice daily had significantly lower Gingival Index and Bleeding Tendency scores at the one-, three-, six-, and nine-month examinations than did the control group. The group using the low-availability Sn2+ gel showed no significant differences in these assessments from the control group. Neither treatment group showed significant differences from the control group in Plaque Index or pocket depth. In the group using the high-availability Sn2+ gel, one subject developed mild coronal staining, and two developed moderate staining.

Microbial succession in recolonizing deep periodontal pockets after a single course of supra- and subgingival debridement

In the present study, the effect of supra and subgingival plaque debridement on the dynamics of the subgingival microflora in deep pockets was investigated. 8 adult periodontitis patients participated in the study. In each patient, 4 clinically diseased sites were investigated microbiologically by phase contrast microscopy for the determination of both the %s as well as the total numbers of spirochetes and motile rods and by anaerobic cultivation for the determination of the different black-pigmented Bacteroides species. After base-line examination, patients were treated by mechanical removal of supra- and subgingival plaque deposits. 2 and 8 weeks after treatment, clinical and microbiological parameters were re-evaluated. During the experimental period, no oral hygiene procedures were performed in order to achieve fast recolonization of the pockets. Treatment resulted in a significant reduction in probing pocket depth and gain of probing attachment. 2 weeks after treatment, no further improvements could be observed. A positive correlation was found between the reduction in probing pocket depth and decrease in Bacteroides gingivalis (P less than 0.009) and between gain in probing attachment and reduction in the % of B. gingivalis (P less than 0.009). No correlation between these clinical parameters and B. intermedius, spirochetes or motile rods was apparent. An inverse relationship between B. gingivalis and B. intermedius was observed. We found that changes in %s of spirochetes and motile rods are not correlated with changes in total numbers of these bacterial groups. It was concluded that monitoring of %s of micro-organisms may not supply rational information on the microbiological conditions of the subgingival area.

Microbial colonization patterns of loosely adherent subgingival plaque in adult periodontitis

Periodontal plaque is a complex bacterial ecosystem that carries an innate history of colonization, selection and maturation. Detailed examination of this balanced environment can reveal developmental sequences and certain interrelationships, much like an archeological record, that can provide insight in the understanding of plaque formation and maturation. For the present investigation, methods are employed which enable the retrospective elucidation of the historical data of plaque development and the nature of bacterial interactions. Nonparametric statistical methods are used to analyze risk, agreement and interdependence, following analytical techniques which are well established in medical epidemiology, but not generally employed in dentistry. The fundamental concept is that many organisms which are present in plaque prefer or require a pre-existing bacterial miliue for colonization and growth to steady-state level. Plaque samples and Ramfjord attachment level measurements were obtained from 60 adult periodontitis patients. Loosely adherent plaque was sampled and different morphotypes were enumerated by darkfield microscopy. The colonization of small spirochetes (S-SP) within the loosely adherent plaque was essential for the colonization of medium spirochetes (M-SP), odds ratio = 15.7 and filaments (FIL), odds ratio = 22.2. Thus, a temporal colonization sequence is inferred for FIL and M-SP, both requiring S-SP as a prerequisite morphotype. Medium spirochetes, in turn, are required for fusiform (FUS) colonization. M-SP also enhance the colonization of FIL and large motile rods (L-MO-R) within the loosely adherent plaque. These morphotypes were inferred to be sequentially interdependent, each preferring or requiring the presence of the preceding morphotype.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal antibodies that recognize a specific surface antigen of Treponema denticola

Spirochetes have been implicated as potential etiologic agents of periodontitis in humans. Murine monoclonal antibodies (MAbs) specific for a serogroup of Treponema denticola, an oral spirochete, were developed and characterized in this study. Antibodies secreted by clone IAA11 were judged to be the most useful, since they were able to detect 8 of 15 T. denticola strains. This MAb consisted of an immunoglobulin G3 heavy chain and a kappa light chain. MAb IAA11 was found to react with an epitope target located on the outer sheath of the cell wall. This MAb should be of diagnostic and scientific value in the study of T. denticola populations in human periodontitis.

Susceptibility of small-sized oral spirochetes to eight antibiotics and chlorhexidine

The purpose of the study was to examine the susceptibility of two different small-sized spirochete morphotypes from subgingival plaque to eight antibiotics and chlorhexidine. MIC-values were determined by a broth dilution method and related to achievable antibiotic tissue- and blood concentrations. The spirochetes were characterized as susceptible, moderate susceptible, and resistant to the different antibiotics. The MICs of tetracycline hydrochloride, doxycycline, penicillin G, and chlorhexidine were all considerably lower for spirochete strains with a 2:4:2 endoflagella system (two endoflagella from each cell-end) than for strains with a 1:2:1 endoflagella system (one endoflagellum from each cell-end). No differences were observed for the remaining antibiotics. Spirochetes containing one endoflagellum from each cell-end were found to be susceptible to metronidazole and doxycycline, susceptible to moderate susceptible to tetracycline hydrochloride, moderate susceptible to penicillin G, and resistant to the remaining antibiotics. Spirochetes containing two endoflagella from each cell-end were susceptible to doxycycline, tetracycline hydrochloride, and metronidazole. Susceptible to moderate susceptible to penicillin G. These spirochetes were resistant to the remaining agents. The significance of these observations is discussed in relation to obtainable gingival crevicular fluid concentrations and treatment of marginal periodontitis.

Experimental vitamin C depletion and supplementation in young men. Nutrient interactions and dental health effects

Biochemical indices of AA clearly showed that the young men in this study were brought into various states of AA depletion and repletion according to their dietary AA intakes. While previous studies have postulated that supplemental intakes of AA may adversely affect body status of vitamins B6 and B12, we found no changes in the B vitamin status of the young men receiving varying AA intakes. Moderate AA supplementation (605 mg/day) showed no antagonistic effect on markers of vitamins B6 and B12. Blood markers of fat-soluble vitamins A and E and iron status were not affected by AA intakes. The propensity of the gingiva to become inflamed or bleed on probing was reduced after normal (65 mg/day) AA intakes as compared to deficient (5 mg/day) intakes and upon supplementary (605 mg/day) AA intakes as compared to normal intakes. The results suggest that AA status may influence early stages of gingival inflammation and crevicular bleeding, and warrant further study of the relationship between AA and periodontal health.

Comparison of dark-field microscopy and a flagella stain for monitoring the effect of a Water Pik on bacterial motility

The purpose of this examiner-blind study was threefold: to compare the microbial counts obtained by two different techniques for assessing bacterial motility, to assess the inter-rater reliability of these two techniques and to evaluate the effect of a water irrigating device (Water Pik) on bacterial motility at 3- and 6-mm probing depths. Subgingival plaque samples were taken from 10 healthy patients having at least two sites that probed greater than 6 mm, (one control, one experimental). Half of the patients were sampled at 3 mm, the other half at 6 mm, both at baseline (Day 0) and at Day 21. Two slides were prepared from each plaque sample, one for dark-field evaluation and one stained with a simplified silver-plating technique for flagella. All slides were read simultaneously by 3 observers, and the per cent motility calculated for spirochetes, motiles and all others. Strong positive inter-rater reliability correlations ranging from r = 0.95 to r = 0.99 were found for both the dark-field and flagella staining techniques. Spirochete counts obtained by both techniques were highly correlated (r = 0.91), whereas counts for motiles resulted in negative correlations between the techniques. Dark-field counts were consistently higher than the flagella stain counts for motile rods. Spirochetes were reduced, but not significantly, after irrigation of both 3-mm and 6-mm sites. Bacterial motility can be evaluated by both dark-field and flagella-staining techniques with a high degree of inter-rater reliability.

Salt and peroxide compared with conventional oral hygiene. II. Microbial results

This study was designed to investigate the effect of conventional oral hygiene (n = 116 subjects) versus a salt and peroxide oral hygiene regimen (n = 115 subjects) on subgingival microorganisms. Subgingival plaque for microscopic evaluation was obtained from eight index tooth sites in each of 231 adult subjects. Microbial forms were microscopically identified at baseline, 8, 16, and 24 months. For both oral hygiene groups, cocci were increased (P less than 0.05) and motile rods were decreased (P less than 0.05) at 8 months and returned to baseline by 16 months. Spirochetes were decreased (P less than 0.05) and remained low through 24 months in both oral hygiene groups. The frequency of agreement between clinical (bleeding) and microbial (greater than or equal to 15% spirochetes or motile rods or greater than or equal to 20% spirochetes + motile rods) criteria for instrumentation was 59.8%. It was also found that fewer total instrumentations for test subjects were observed when microbiological criteria were used as compared with clinical criteria. The greater number of instrumentations based on clinical criteria was highly significant (P less than or equal to 0.001). A significant change in microbial signs associated with peridontal disease may be obtained with either a conventional oral hygiene or a salt and peroxide oral hygiene home care regimen.

The effects of antiformin-citric acid chemical curettage on the microbial flora of the periodontal pocket

This study investigated the hypothesis that antiformin-citric acid chemical curettage combined with scaling and root planing (SRP/AF) would significantly reduce pathogenic bacteria of the periodontal pocket when compared to scaling and root planing alone (SRP). Ten patients with moderate periodontitis participated. Four pockets per patient, one in each posterior sextant, were chosen. Pocket depths, attachment levels, and gingival index (GI) were measured. Bacterial samples were examined under dark-field microscope for: (1) spirochetes, (2) motile rods, and (3) all others. A randomized four-sextant treatment design was used. One sextant received no treatment, a second received SRP, and the two remaining sextants received identical treatments of SRP/AF. Of these two sextants, one was sampled at baseline and 12 weeks only in order to serve as an additional control. The remaining sextants were sampled at 1, 4, 8, and 12 weeks. Both SRP and SRP/AF significantly reduced the percentage of spirochetes and motile rods. A significant reduction in GI and pocket depths was also noted. Attachment level showed no significant change. Results of both treatment groups showed no significant differences among any of the parameters. A comparison of the two SRP/AF groups indicated no significant difference among clinical or bacterial parameters due to sampling.

A comparison of the effectiveness of hand scaling and ultrasonic debridement in furcations as evaluated by differential dark-field microscopy

There have been no previous reports in the literature comparing the effects of hand scaling with ultrasonic debridement in furcations, or which have used dark-field microscopy for this comparison. The purpose of this study was to compare the efficacy of these two modes of debridement in various classes of furcations, using gingival crevicular fluid flow and dark-field microscopy as parameters. A total of 33 furcated molars were evaluated. Results indicated that both hand scaling and ultrasonic debridement were equally effective in Class I furcations in changing the gingival fluid flow and bacterial proportions to those of a healthy state. In contrast, ultrasonic debridement was significantly more effective than hand scaling in Class II and Class III furcations in altering these parameters.

Juvenile periodontitis--a new perspective

Juvenile periodontitis (JP) is a severe disease of the periodontium in adolescents. It is usually localized to the first permanent molars and (less commonly) the central incisors. The bacteria Actinobacillus actinomycetemcomitans (Aa) is currently implicated in the aetiology of JP since its numbers are high in JP pockets and low in subjects with healthy periodontal conditions or with adult periodontitis. However, Aa harvested from JP pockets and transferred to healthy sites in the same mouth are unable to colonize these areas or initiate disease (17). The conflicting evidence implicating intrinsic or induced impairment of host defence is reviewed. It is hypothesised that JP lesions are primarily of endodontic origin. By-products of an inflammatory process in the pulp enter the periodontium via dentinal tubules, lateral or furcation canals and drain through the periodontium into the mouth. The environmental conditions of the sinus select for bacteria such as Aa which secondarily infect the site and exacerbate the clinical situation by their potent virulence factors. Localized deep defects involving only one side of an interproximal space in an otherwise periodontally healthy mouth result. Studies of the pulpal status of JP teeth are indicated.

Distribution of morphologically different micro-organisms associated with active periodontal lesions

The morphological composition of the subgingival plaque associated with active periodontitis lesions and comparable inactive control lesions were determined in a 36-year-old patient with advanced periodontal disease. Monthly measurements of the clinical attachment level were subjected to linear regression analysis as a function of time. Attachment loss was recorded during the monitoring period at 10 sites, with loss of 2 mm or more at 6 sites. Plaque samples taken from these 6 sites and from 6 control sites with similar clinical conditions were not of uniform composition. Active lesions harboured on average 46% more cocci and twice as many large spirochetes as inactive control lesions. A linear regression analysis of the proportions of different morphotypes in the subgingival plaque versus the calculated monthly attachment loss rate at the time of sampling provided only very weak correlations, if at all. The observations made in the patient under investigation suggest that there is no great probability of suspected differences in the floras of active and inactive lesions being detected by dark-field analysis alone. The role of motile rods and spirochetes may have been over-rated hitherto.

Morphological distribution of spirochetes in subgingival plaque from advanced marginal periodontitis in humans

The purpose of this study was to elucidate the distribution of spirochetes (SP), on the basis of ultrastructural criteria in subgingival plaque from patients with advanced marginal periodontitis. Samples were obtained by a paperpoint technique from 18 pockets 6-10 mm in depth from 12 individuals. On grids with negatively stained material, more than 50 SP were photographed from each sample. The SP were primarily grouped according to the number of endoflagella from each cell-end, with the exception of SP with more than eight endoflagella, which were pooled in one group. The diameter, the length, the wavelength and the amplitude of the SP were measured and related to the number of the endoflagella. The 95 per cent and 99 per cent confidence intervals were estimated. Owing to the number of endoflagella, the distribution of SP varied in the separate samples and no relationship to pocket depth was found. SP containing two endoflagella were the pre-dominating type. On the basis of the dimensions of the diameter, the length, the wavelength and the amplitude, the SP fell into four significantly different morphological groups characterized by 1, 2, 3-8, and more than 8 endoflagella, as the values in general increased from group to group.

Dark ground microscopy in relation to 3 clinical parameters of chronic inflammatory periodontal disease

This paper examines the relationships between 3 clinical parameters: pocket depth, gingival index, and bleeding index and 2 laboratory parameters: spirochaete counts and motility counts on the basis of analysis of 883 observations made in the mouths of 41 patients. The results were consistent with the findings of other studies in that deeper pockets tended to harbour higher %s of spirochaetes and motile organisms. The same overlap between all the parameters in general and between spirochaetes and pocket depth in particular as existed in our previous study was demonstrably evident. 8% of shallow pockets had spirochaete counts in excess of 20% and 79% of deep pockets had spirochaete counts of less than 20, 18% having no demonstrable spirochaetes. These results are consistent with those of our previous study and with the findings of Evian et al. that even in pockets of the order of 7 mm, the proportions of spirochaetes found varies from what may be expected at healthy sites to what may be expected at diseased sites.

Clinical alterations in relation to the morphological composition of the subgingival microflora following scaling and root planing

The aim of the present study was to relate shifts in the composition of subgingival plaque in periodontal pockets to alterations of the clinical periodontal conditions following a single course of subgingival scaling and root planing during a period of professional supragingival plaque control. For this purpose, 36 pairs of contralateral periodontal pockets in 10 subjects with moderately advanced periodontitis were assessed for the degree of gingival inflammation, probing pocket depths, bleeding on probing, attachment levels and the amount of supragingival plaque. In addition, samples of subgingival plaque were analyzed morphologically by dark-field microscopy. All patients received detailed information about proper oral hygiene and every 1-2 weeks, professional removal of supragingivally located deposits. When the oral hygiene standard had been sufficiently improved, 1 course of subgingival scaling on 1 side of each jaw only (test side) was carried out. Clinical and microbiological examinations were repeated after the scaling as well as after 2 and 6 months, while patients were recalled for supragingival prophylaxis every 2nd to 4th week. Our data showed that a single course of subgingival scaling and root planing resulted in reduced probing depths, a gain in clinical attachment and a shift in the composition of the subgingival microflora to a composition found in relatively healthy periodontal conditions. In relatively shallow pockets, however, a possible influence of repeated sampling on the subgingival microflora could not be ruled out. Bleeding on gentle probing was a reliable parameter for predicting a subgingival microflora where motile bacteria hold an increased portion.(ABSTRACT TRUNCATED AT 250 WORDS)

False results associated with darkground microscopy of subgingival plaque

This study considers false results which may arise due to problems in the preparation or examination of specimens for darkground microscopy of subgingival plaque. Subgingival plaque samples obtained with a sterile curette were placed in 0.1-0.3 ml sterile full or 1/4 strength Ringer's solution: 0.85% saline, 1% gelatin in 0.85% saline, formal saline or pyrogen-free water for injection. Test slides were prepared from the original dispersion, and control slides from the corresponding sterile solution. Optimal dispersion solution, syringe dispersion frequency and the effect on motility of delay in processing samples were tested. Slides were also prepared from dispersions of 11 representative subgingival "periodontopathic" organisms. Problems in sampling included variability in counts between sites with comparable pocket depths, contamination of the sample and reduction of the sample volume after scaling. Problems in dispersion included contamination, uneven distribution of the different morphotypes and destruction of delicate organisms. Problems in slide preparation included slide contamination, limitation in the number of samples that can be assessed by one examiner at a given time without loss of activity of motile cells, and preparation of a cell monolayer. Problems in identification and counting included confusion of Brownian movements with motility, coccoid particles with cocci, spirochetes with campylobacter, flagella with flagella-like structures, size of cocci, counting of fragmented spirochetes and non-motile flagellated organisms and motile cells, and also bias in counting. Problems in morphotype grouping included the observation that many (10 of the 11 representative) periodontitis-related organisms were in the non-motile groups and not all cells of the motile species (Campylobacter, Capnocytophaga) showed motility. The results indicate that each stage of subgingival plaque darkground microscopy, sampling, dispersion, slide preparation, counting, morphotype grouping and interpretation may lead to false results if not representative or reproducible. Procedures are suggested for the minimisation of problems in the preparation and examination of subgingival plaque specimens for darkground microscopy.

Subgingival microflora in bleeding and nonbleeding pockets

The subgingival flora of bleeding and nonbleeding 4-6 mm pockets was investigated using phase-contrast microscopy. Subgingival plaque was sampled from 11 patients with generalized moderate periodontitis. 4 subgingival samples were obtained from each patient, 2 from sites that bled upon standardized probing force and 2 from sites that did not. The amounts of gingival inflammation, supragingival plaque, attachment level and pocket depth were also assessed at each site. The %s of 4 bacterial morphotypes were assessed using phase-contrast microscopy. No significant differences were found in the %s of cocci, motile rods, or spirochetes between bleeding and nonbleeding sites. Significant correlations were found, however, between the % of spirochetes and probing depth, attachment level, and gingival inflammation. The observations indicate that the use of bleeding on probing may not be justified as an indicator of infection by those "periodontopathic" bacteria identifiable by phase-contrast microscopy. However, limitations in the microscopic method may have prevented us from observing differences between the 2 types of sites on a species level.

Fluorescent antibody and flagella stains for rapid detection of bacteria at periodontally healthy and diseased sites

Two rapid methods of identifying bacteria associated with periodontal disease were investigated to determine their diagnostic usefulness in longitudinal or epidemiologic studies. Three nonmotile organisms were identified by fluorescent antibody stains (FA) while percentages of motile bacteria were assessed by counting all spirochetes, flagellated and nonflagellated organisms stained with a simplified silver-plating stain for flagella. Relationships between disease activity and these bacteria from subgingival plaque samples taken at 18 individual sites (12 diseased, 6 healthy) were determined by correlating the quantity of detectable bacteria with the Gingival Index (GI), Plaque Index (PLI) and probing depth (PD). The highest correlations found with the FA stains were between Bacteroides gingivalis and probing depth (rs = 0.85), GI (rs = 0.80) and PLI (rs = 0.80). Bacteroides melaninogenicus and/or Bacteroides intermedius also correlated well with the GI (rs = 0.66), PLI (rs = 0.64), and PD (rs = 0.59), but to a lesser degree than B. gingivalis. Flagella stains showed that spirochetes correlated highly with PD (rs = 0.82), as did the total motile group with PLI (rs = 0.82). Motile bacteria alone were only moderately associated with the clinical parameters measured. The results of this investigation suggest that FA- and flagella-staining methods can be valuable screening tools for the detection of bacterial species and motile organisms in longitudinal or epidemiologic studies.

Serum IgA and IgG antibodies to Treponema vincentii and Treponema denticola in adult periodontitis, juvenile periodontitis and periodontally healthy subjects

13 patients with untreated adult periodontitis (AP) were compared to 8 subjects free of periodontal disease (H) with respect to plaque index (PlI), gingival index (GI), probing depth (PD) and differential counts of subgingival bacterial morphotypes from a pooled sample of 6 surfaces with the greatest probing depth. Serum antibody levels to T. vincentii and T. denticola strains were also determined in these subjects as well as in the sera from 5 subjects with localized juvenile periodontitis (LJP). Subjects with AP had significantly elevated proportions of spirochetes and motile rods and lower proportions of coccoid cells than H subjects. They also exhibited significantly higher PlI and GI scores and greater probing depths. Antibody levels were normalized against a standard serum and expressed as ELISA units (EU). IgA and IgG antibody levels to all tested spirochete strains were significantly elevated in AP subjects as compared to subjects in group H or subjects with LJP. No significant differences in antibody titers were detectable between the H and LJP groups with respect to any of the tested strains. No significant correlation could be demonstrated between serum antibody titers to any of the oral spirochete strains tested and the proportions of oral spirochetes determined microscopically.

Microscopic agglutination and polyacrylamide gel electrophoresis analyses of oral anaerobic spirochetes

Microscopic agglutination (MA) analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to determine strain and species similarities and dissimilarities among three species of oral anaerobic spirochetes, Treponema denticola, Treponema pectinovorum, and Treponema vincentii. The MA analysis revealed a diversity of serologic reactivity or sharing of common antigens within each species. However, there was no cross-reactivity or sharing of common antigens among the three species. Distinct SDS-PAGE whole-cell electrophoretograms for each species were obtained. The banding patterns for 16 T. denticola strains revealed 30 distinct proteins, while the banding patterns for 5 strains of T. pectinovorum and 2 strains of T. vincentii revealed 26 and 35 distinct proteins, respectively. Analysis of the electrophoretograms showed that their respective banding patterns could be used to distinguish the three species from one another. In addition, strain differences within each species could be detected. There was a correlation between MA analysis and SDS-PAGE analysis. It is thus suggested that both MA and SDS-PAGE analysis be included in classification schemes for the identification of oral spirochetes.

Subgingival microflora and periodontal conditions in healthy teenagers

The composition of subgingival flora was correlated with clinical periodontal conditions in 100 teenagers aged 12 to 17 years. The Community Periodontal Index of Treatment Needs (CPITN) was used for the clinical examination. Subgingival bacterial samples were taken from the mesial surface of each first molar, two samples for dark-field microscopy and two samples for Actinobacillus actinomycetemcomitans (A.a.) cultivation. Fifty-nine subjects had at least three healthy sextants. Score 1 was the highest CPITN recording in 61 subjects and Score 2 in 30 subjects. None had scores 3 or 4. In dark-field microscopy, cocci predominated in most samples. Straight rods, fusiforms and motile rods correlated negatively to the number of healthy sextants per subject. Straight rods and fusiforms showed a positive correlation to gingival bleeding tendency at the sampled site. A.a. was isolated in four subjects. Motile microorganisms and A.a. were detected rarely in subjects with good periodontal conditions.

A new method for assessing the % of spirochaetes in subgingival plaque

A new method for counting the numbers of spirochaetes in subgingival plaque is described. The technique involves the combined use of a negative stained preparation, dark field microscopy, and an image analysing system. Advantages of the method include: smears need not be made until 2 days after sampling, and can be examined microscopically for up to 1 year after preparation; reproducibility of counts are more than 90% and the data can be computerised. The new method should prove useful in the routine assessment of subgingival plaque from patients with various forms of periodontitis, and in epidemiological surveys.

The effect of controlled ascorbic acid depletion and supplementation on periodontal health

To determine if systemic levels of vitamin C influence periodontal health, changes in plaque accumulation, gingival health and periodontal probing depth were measured in healthy subjects housed for 3 months in a nutrition suite that provided controlled periods of ascorbic acid depletion and supplementation. Eleven healthy, nonsmoking men, aged 19 to 28 years, ate a rotating 7-day diet adequate in all nutrients except ascorbic acid. This basal diet, which contained less than 5 mg/day ascorbic acid, was supplemented with 60 mg/day ascorbic acid for 2 weeks, 0 mg/day ascorbic acid for 4 weeks, 600 mg/day ascorbic acid for 3 weeks and 0 mg/day ascorbic acid for 4 weeks. Plasma, urine and leukocyte ascorbate levels, Plaque Index, Gingival Index, Bleeding Index and probing depths were monitored throughout the study. A uniform oral hygiene program was maintained in which oral hygiene instructions were reinforced bi-weekly. Ascorbate concentrations in body fluids and leukocytes responded rapidly to changes in ascorbic acid intake. No mucosal pathoses or changes in plaque accumulation or probing depths were noted during any of the periods of depletion or supplementation. However, measures of gingival inflammation were directly related to the ascorbic acid status. The results suggest that ascorbic acid may influence early stages of gingivitis, particularly crevicular bleeding.

Experimental gingivitis in relation to susceptibility to periodontal disease. II. Phase-contrast microbiological features and some host-response observations

In the present investigation, a number of histological and immunohistochemical characteristics of periodontal tissues as well as the phase-contrast microscopy of dental plaque were studied after experimentally-induced gingival inflammation in relation to susceptibility to periodontal disease. The study included a younger (mean age 34.1 years) and an older age group (mean age 48 years) with a reduced but healthy periodontium. Both age groups had the same amount of loss of attachment which may suggest that they had different degrees of susceptibility to periodontal disease. At the start of the experiment, each patient was instructed to abstain from oral hygiene in one quadrant of the mouth for a period of 18 days. At the end of the 18-day period, supra-gingival plaque and gingival tissue samples were taken. As determined by phase-contrast microscopy, the plaque samples of both age groups contained relatively high proportions of spirochetes. This may indicate that the patients are at risk for recurrence of periodontal breakdown. The general histopathologic picture of the gingival tissue samples of both age groups was similar to the so-called 'early lesion'. However, IgA-producing plasma cells were found in most tissue samples of both age groups. The first part of this study showed that the younger, in comparison to the older, patients developed inflammation in terms of bleeding on probing more rapidly. These clinical results cannot be explained by the host-parasite parameters investigated in the present study.

Nutrient and environmental growth factors for eight small-sized oral spirochetes

The present investigation was carried out in order to obtain better information about the growth requirements for small-sized oral spirochetes containing two endoflagella from each cell-end. Eight strains of such spirochetes were isolated from subgingival plaque in patients suffering from advanced marginal periodontitis. The strains were maintained under anaerobic conditions in a fluid basal BHI medium with 15% inactivated rabbit serum, 0.07% Noble Agar and 5 micrograms/ml cocarboxylase. Firstly, the effect of trace amounts of oxygen in the atmosphere and pH in the medium on growth of the spirochete strains were examined. Secondly, the effect of different sera incorporated in the medium was examined, and thirdly, the effect of important growth factors in serum was studied by adding different serum components to the fluid basal medium instead of rabbit serum. Growth was always determined after 4 days' incubation at 35 degrees C, either by counting numbers of spirochete cells in a Petroff-Hauser counting chamber or by measuring the turbidity of the culture spectrophotometrically at 600 nm. There was no difference in growth by using an atmosphere containing 1% oxygen or an anaerobic atmosphere. It was found that serum (rabbit or human) was an essential growth component, and no single growth factor could replace rabbit serum. Only a long chain fatty acid mixture and an amino acid solution could, to a minor extent, stimulate growth compared to the basal medium without rabbit serum. Sodium bicarbonate inhibited growth of all strains. Finally, none of the strains fermented a series of low molecular weight carbohydrates, but all strains produced H2S and indole.

Enzyme activities from eight small-sized oral spirochetes

The purpose of the present investigation was to detect strains of small-sized oral spirochetes isolated from subgingival plaque for protease, peptidase, lipase, glycosidase, phosphatase, hyaluronidase and chondroitinsulfatase activities. The analyses were routinely carried out with cultures in the early stationary phase of growth after 4 days incubation. Both culture media and harvested spirochete cells were examined for the different enzyme activities. The enzymes were assayed by use of the API ZYM system, by p-nitroanilide derivatized peptides, and by hydrolyzing of mucopolysaccharides incorporated in solid bacterial medium. Relatively strong activities of trypsin-like enzymes, mainly bound to the cells, were observed in all strains. Similarly all strains showed acid phosphatases bound to the cells, too. Extracellular hyaluronidase- and chondroitinsulfatase activities were detected qualitatively in all strains after 7 days growth. The activities of the two mucopolysaccharide degrading enzymes almost disappeared after 10 subcultivations. Weak lipase (butyrate), higher lipase (caprylate), and weak phosphoamidase activities were observed in all cell pellets. No glycosidase activities were found. The observations are discussed by regarding the spirochetal enzymes as potential virulence factors for the development of marginal periodontitis.

The prevalence of spirochetes in the subgingival microbiota of Tanzanian and Dutch children

The subgingival microflora of 71 Tanzanian and 77 Dutch prepurberty children was analyzed by dark-field microscopy. Spirochetes were observed in almost every Tanzanian child and in 66% of the Dutch children. The predominant spirochetes were small and medium sized; large spirochetes were infrequently observed in the rural Tanzanian children and at the bleeding sites of the Dutch children. Further differences in the %s of cocci, rods and fusiforms indicated that the subgingival microflora of Tanzanian children is different from that of Dutch children. Generally, spirochetes occurred at higher %s and frequency at bleeding sites than at non-bleeding sites in both populations. However, the non-bleeding sites in the Tanzanian children had a higher prevalence of spirochetes than the bleeding sites in Dutch children. It is concluded that spirochetes are members of the normal flora of prepuberty children, that in children gingivitis is associated with increased proportions of spirochetes and that the presence of spirochetes in the gingival crevice is not dependent upon gingival inflammation.

Microbial populations and active tissue destruction in experimental periodontitis

Although specific subgingival microflora are being associated with active tissue destruction in periodontitis, little information exists on the relationship between subgingival flora and histological evidence of tissue destruction. The present study was undertaken to explore these relationships during experimental marginal periodontitis in squirrel monkeys. In 4 squirrel monkeys, experimental periodontitis was induced around bicuspids and molars using silk ligatures. The buccal part of the subgingival ligature was removed for bacterial sampling 3, 7, and 14 days after ligature placement. Dark-field microscopy was used to quantify motile forms, spirochetes, straight and curved rods, filaments, cocci and fusiforms. Subgingival plaque prior to periodontitis induction was dominated by cocci, but fusiforms and straight rods were also present. Spirochetes, filaments, curved rods and motile forms were absent. 3 days after induction of periodontitis, there were marked increases in spirochetes, motile forms, filaments, curved and straight rods. The proportions of coccoids and fusiforms decreased. The bacterial proportions stayed at approximately the same levels through 7 and 14 days. Histometric quantification of periodontal destruction showed loss of connective tissue attachment and crestal alveolar bone. A positive correlation was found between periodontal tissue destruction and both total number of subgingival bacteria and spirochetes.