Wolinella recta in adult gingivitis and periodontitis

Wolinella recta has been associated with adult periodontitis, but its role in the disease remains uncertain. This report clarifies the distribution of W. recta in periodontally healthy and diseased subjects, and treated patients with recurrent disease. A specific polyclonal rabbit antiserum against W. recta strain 372 was used for indirect immunofluorescence localization of W. recta in dental plaque from untreated and treated patients. Supragingival plaque was collected from 15 periodontally healthy individuals (H), 10 adults with mild gingivitis (G1), 8 with severe gingivitis (G2) and 15 with periodontitis (AP). Subgingival samples from 23 diseased sites (G2 and AP) were examined as well. There was a significant difference (p = 0.000) between the proportions of W. recta in subgingival (4.4%) vs. supragingival (0.3%) plaque samples from AP. A significant difference (p = 0.000) in W. recta proportions was also detected between subgingival plaque samples of AP (4.4%) vs. G2 (1.2%). No significant difference in the mean % of W. recta was found between supragingival plaque of AP (0.3%) and G2 (0%), and samples of G1 (0.01%) and H (0.1%). In a separate study, 85 adults previously treated for moderate to severe adult periodontitis were monitored over a 12-month period for evidence of disease recurrence. Recurrent disease was detected at 32 sites in 18 subjects. Of these, 20 sites in 13 subjects were positive for W. recta. With subjects as the experimental unit, a significant increase in the proportions of W. recta was found at sites with recurrent disease (3.12%) as compared to stable, paired control sites (0.24%), but only when sites with breakdown and positive for W. recta were compared with their controls. These results indicate that W. recta is associated with some, but not all sites with advanced adult periodontitis. The association of W. recta with gingivitis was not statistically significant.

Immunosuppressive effects of Prevotella intermedia on in vitro human lymphocyte activation

In this study, we have assessed four strains of Prevotella intermedia, isolated from periodontally involved lesions, for their ability to inhibit lymphocyte functions. All four strains were found to cause a dose-dependent inhibition of B- and T-cell proliferation in response to mitogens and antigens. This was reflected in altered DNA, RNA, and protein syntheses. Furthermore, P. intermedia appeared to affect the early stages of cell activation. This was ascertained by kinetic analysis in which it was determined that the extract had to be present during the first 24 h of incubation to cause suppression. Moreover, direct assessment of the early stages of cell activation indicated that release of cytokines and expression of the interleukin 2 receptor and CD69 on T cells were inhibited by P. intermedia sonic extracts. Finally, preliminary characterization of the immunosuppressive agent indicates that it has a molecular mass of approximately 50 kDa and is heat labile. It has been proposed that impaired host defense may play a pivotal role in the pathogenesis of many infections. The data presented in this paper suggest that microbially mediated immunosuppression may contribute to the pathogenesis of periodontal disease by altering the nature and consequences of host-parasite interactions.

Subgingival microflora of advanced periodontitis in the Dominican Republic

A study of the predominant subgingival microflora was carried out in 24 periodontitis patients, 18 to 60 years of age, in Santo Domingo, Dominican Republic. Paper point sampling, transport in VMGA III, and conventional microbiological techniques were utilized. Direct microscopic examination revealed that cocci and nonmotile organisms made up 85% of the total organisms and spirochetes as little as 3%. Nonselective culturing showed Gram-negative organisms to constitute 53% of total isolates. Fusobacterium nucleatum averaged 15%, black-pigmented anaerobes 7%, and Peptostreptococcus micros 10% of the cultivable microflora. Enteric rods and acinetobacter species were recovered from 16 patients and comprised 23% of the cultivable flora. Enterobacter cloacae occurred in 8 patients, Klebsiella oxytoca in 3 patients, and 7 other species in 10 patients. Parallel studies have found a significantly lower prevalence of enteric rods in advanced periodontitis patients in the USA. In conclusion, fewer spirochetes and markedly more enteric rods seem to inhabit adult periodontitis lesions in Santo Domingo patients compared to those in USA. High levels of subgingival enteric rods in periodontitis patients in Santo Domingo may have important prophylactic and therapeutic implications.

Clinical and microbiological findings on newly inserted hydroxyapatite-coated and pure titanium human dental implants

The clinical and microbiologic features of 30 hydroxyapatite-coated root-form endosseous dental implants (Tri-Stage) were compared to 10 similar pure titanium implants without hydroxyapatite coatings. In 7 of 9 partially edentulous patients studied, pure titanium fixtures were placed adjacent to hydroxyapatite-coated implants. Implants in the maxilla were submerged beneath mucosal tissues after implant placement for a minimum of 6 months, and in the mandible for at least 4 months. All patients were prescribed short-term beta-lactam antibiotic therapy after fixture placement, and 8 of 9 used chlorhexidine mouthrinses after fixture exposure. Clinical and microbiological examination was carried out 7-10 months after fixed prosthetic loading of the implants. Clinical measurements included the gingival index, plaque index, bleeding on probing and peri-implant probing depths determined with the Florida Probe system. Subgingival microbial samples were collected with paper points and transported in VMGA III. Specimens were examined by direct phase-contrast microscopy and were plated onto nonselective and selective culture media for anaerobic and aerobic incubation. No significant mean clinical or microbiological differences were found between the implant types, although one hydroxyapatite-coated implant exhibited deep probing depths, bleeding on probing and marked radiographic crestal bone loss. Streptococcus sanguis and Streptococcus mitis were the most predominant organisms recovered from clinically stable implants, whereas high proportions of Fusobacterium species and Peptostreptococcus prevotii were isolated from the ailing hydroxyapatite-coated implant. One or more implants in 8 of the study subjects yielded enteric rods, pseudomonads, enterococci or staphylococci. The prognosis of implants with varying early microbiotas needs to be established in longitudinal studies.

New views on periodontal microbiota in special patient categories

The microorganisms in periodontitis of special patient categories have been only partially elucidated. The periodontitis microbiota of HIV-infected individuals, cancer patients on myelosuppressive therapy, and persons with other medical disorders includes common suspected periodontal pathogens as well as enteric rods, pseudomonads, staphylococci and yeasts. Failing implants also may be associated with classical periodontal pathogens as well as primarily nonoral potential pathogens. Refractory periodontitis in systemically healthy adults can show a great variety of oral and nonoral organisms. The frequent occurrence of unusual periodontal organisms in special patient categories may be due to a weakened host response and/or usage of various chemotherapeutic regimens. The unusual organisms may contribute to progressive periodontitis and in leukemia patients may even give rise to life-threatening systemic manifestations. The primary therapeutic goal in special periodontitis patients is control of pathogens and amid the wide range of pathogenic microfloras, an effective treatment strategy should include a comprehensive microbiological analysis, especially if systemic antimicrobial therapy is contemplated.

Microbial differences in 2 clinically distinct types of failures of osseointegrated implants

The microflora associated with osseointegrated implants suspected of failing from infection or trauma were evaluated. Of 75 patients examined, 11 demonstrated failing fixtures. 22 of 48 fixtures failed in 6 fully edentulous patients and 10 of 34 failed in 5 partially edentulous patients. The etiology of failure was attributed to infection if there was bleeding, suppuration, pain, high plaque and gingival indices and granulomatous tissue upon surgical removal. Traumatic etiology was suspected in the absence of these signs. Direct phase-contrast microscopy and culture analysis were performed on samples from the implant sulcus, the implant itself and the extraction socket. The 2 failure types exhibited distinct bacteriologic profiles. For implants failing with infection, spirochetes and motile rods averaged 42% of total morphotypes. Many suspected periodontopathic organisms including Peptostreptococcus micros, Fusobacterium species, enteric gram-negative rods and yeasts, constituted high proportions of the cultivable microflora. In contrast, implants failing from suspected traumatic etiology demonstrated a morphotype profile consistent with periodontal health and cultivable microflora predominated by streptococci. When evaluating the time of failure after initial insertion, it was found that fixture loss resulting from infection occurred most often between initial placement and second-stage surgery, whereas failure in the absence of infection occurred primarily after insertion of the final prosthesis. The terms infectious and traumatic failure have been introduced to describe these 2 clinically and microbiologically distinct phenomena.

Candida biotypes in human adult periodontitis

Fifty-five Candida isolates from human periodontal pockets were biotyped using the API 20C micromethod kit system. Candida albicans (11 biotypes) constituted 81.8% of all yeast isolates. A single biotype accounted for 57.8% of the subgingival C. albicans strains. The biotype distribution of C. albicans in human periodontal pockets appears to follow a selectivity pattern similar to that of other oral surfaces.

Incidence of periodontitis recurrence in treated patients with and without cultivable Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Porphyromonas gingivalis: a prospective study

A total of 98 adults previously treated for moderate to advanced periodontitis and on a trimonthly recall schedule were screened for the presence of critical levels of Actinobacillus actinomycetemcomitans, Prevotella (Bacteroides) intermedia, and Porphyromonas (Bacteroides) gingivalis. Patients with at least 2 positive sites were placed in a positive group and patients without or with low levels of these bacteria in a negative group. During the 30-month study the incidence of disease recurrence was greater in the positive group, but did not reach statistical significance. Positive patients with deeper pockets tended to be at greater risk of developing recurrent disease than those with shallower pockets. In the positive group only, both A. actinomycetemcomitans recovery and antibody levels to A. actinomycetemcomitans strain NCTC 9710 (serotype c) were inversely correlated with disease recurrence. The presence of A. actinomycetemcomitans and P. intermedia above critical levels did not reliably predict future episodes of disease recurrence in this population. The sparse recovery of P. gingivalis did not permit us to assess its diagnostic value. With the exception of P. gingivalis, for which insufficient data were available, the results indicate that the presence or absence of the above bacterial species cannot of itself serve as a reliable predictor of future episodes of recurrent disease in a population of treated patients on a regular trimonthly recall schedule.

Distribution of Actinobacillus actinomycetemcomitans serotypes in periodontal health and disease

A total of 177 Actinobacillus actinomycetemcomitans isolates from 136 periodontally healthy or diseased subjects were serotyped by indirect immunofluorescence and/or immunodiffusion assays. Serotype-specific rabbit antisera against A. actinomycetemcomitans serotypes a, b and c were used. All 3 serotypes were commonly found in the study subjects. Serotype b was dominant in subjects with periodontal disease and serotype c was the most common serotype in the healthy subjects. In the immunofluorescence assay, when 85 isolates were cultured anaerobically and fixed in acetone, or cultured aerobically in 10% CO2 and heat-fixed, 60 isolates revealed the same serotypes. The remaining 25 isolates reacted with 2 of the serotype-determining reagents. In the immunodiffusion assay, 22 of these 25 isolates reacted with one antiserum only. These results suggest differences in the distribution of A. actinomycetemcomitans serotypes between periodontal health and disease and point to possible variation in serotype determination due to bacterial growth and preparation procedures.

Antibiotic prophylaxis for medical-risk patients

The three current regimens for the prevention of infective endocarditis are discussed and compared along, with at-risk patients and dentally-induced bacteremias. The principles of antibiotic prophylaxis, and other medical conditions where antibiotic prophylaxis is controversial or inadequately documented is critically analyzed.

Microbial aspects of failing osseointegrated dental implants in humans

The subgingival microflora of 18 failing implants were examined for pathogenic periodontal microorganisms. Peptostreptococcus micros was recovered from 6 failing implants, Wolinella recta from 6, Fusobacterium species from 5, Candida albicans from 5, and Bacteroides intermedius from 4. Enteric rods or pseudomonads constituted a significant part of the microflora in 5 failing implants. Actinobacillus actinomycetemcomitans, nonpigmented Bacteroides species, Capnocytophage species, and staphylococci were detected in a few implant failures. The present study showed that a complex microflora comprising oral as well as primarily non oral organisms, and bacteria as well as yeasts, can be associated with failing implants. This great diversity in microbial composition and antimicrobial susceptibility among "peri-implantitis" isolates suggest that antimicrobial therapies for implant failures should not be implemented without a prior comprehensive microbiological analysis.

In vitro activity of chlorhexidine against enteric rods, pseudomonads and acinetobacter from human periodontitis

Fifty-eight periodontal isolates of the families Enterobacteriaceae and Pseudomonadaceae, and the genera Acinetobacter and Achromobacter were studied to determine their susceptibility to Peridex (0.12% chlorhexidine digluconate solution; Procter & Gamble). In an agar dilution assay, about 50% of the study strains grew in the presence of 70 micrograms/ml of chlorhexidine. Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Pseudomonas cepacia, and Serratia marcescens comprised the most resistant species. Studies are needed to determine the microbiological and clinical effects of chlorhexidine usage in patients infected with enteric rods and pseudomonads.

Microbiological study of HIV-related periodontitis

The subgingival microbiota in 14 persons with HIV-periodontitis was examined. Subgingival plaque samples were collected with paper points, transported in VMGA III, and plated on anaerobic enriched brucella blood agar and various selective media. HIV-periodontitis sites revealed Actinobacillus actinomycetemcomitans, Wolinella recta, Peptostreptococcus micros, and Bacteroides intermedius, each averaging 7% to 16% of the cultivable subgingival flora in positive patients. High levels of spirochetes also were detected in diseased sites with phase-contrast microscopy. Low levels of Candida albicans or enteric Gram-negative rods were recovered in the subgingival flora in 7 HIV-periodontitis patients or Bacteroides fragilis, Fusobacterium necrophorum, Fusobacterium varium, and Eubacterium aerofaciens were recovered in 8 patients. These findings suggest that the major components of the subgingival microbial flora in HIV-periodontitis are similar to those associated with adult periodontitis in systemically healthy persons. However, HIV-periodontitis lesions also may contain organisms which are rarely found in common types of periodontitis. The etiological significance of specific periodontal organisms in HIV-periodontitis awaits further longitudinal study.

Age and sex relationships of superinfecting microorganisms in periodontitis patients

The occurrence by age and sex of subgingival enteric rods and pseudomonads, yeasts, and staphylococci was studied in 3075 "refractory" periodontitis patients referred for microbiological analysis. Each subject contributed a pooled subgingival sample obtained from 3 deep periodontal pockets with paper points. Selective and nonselective media and commercial identification kit systems were used for microbial isolation and speciation. Females constituted about 60% of the study subjects, and almost one-third of all patients were in their forties. Females (47.3%) showed a higher prevalence of the study organisms than males (43.9%). Older females (15.9%) and males (15.3%) revealed significantly higher prevalences of enteric rods and pseudomonads than younger individuals (10.9%), and older infected females yielded significantly higher viable counts than younger infected females. The sexes demonstrated a similar prevalence of staphylococci (about 28%), but younger infected females and males showed significantly higher viable counts than older infected individuals. No sex or age relationships were found for yeasts (about 14% of individuals infected). The high level of subgingival enteric rods and pseudomonads in some individuals may be important in the pathogenesis of geriatric and other forms of periodontitis and may have therapeutic implications.

Actinobacillus actinomycetemcomitans and Bacteroides intermedius in human periodontitis: age relationship and mutual association

This study examined age relationships and mutual interrelationships between cultivable Actinobacillus actinomycetemcomitans and Bacteroides intermedius in 1624 periodontitis patients, 15 to 89 years of age. Each subject contributed a pooled subgingival sample, obtained from 3 deep periodontal pockets with paper points. A. actinomycetemcomitans occurred with higher prevalence (74%) and mean recovery (7% in culture-positive patients) in patients less than 25 years old than in adult and geriatric patients (prevalence about 31%; mean recovery about 1%). The organism was detected in 85% of localized juvenile periodontitis patients. B. intermedius was recovered from 45% of the study subjects, averaged about 7% of total isolates in positive patients, and showed no predilection for any age group. As determined from predicted and observed values for A. actinomycetemcomitans and B. intermedius, occurring alone and in combination, no synergistic or antagonistic relationships between the organisms could be delineated with respect to subgingival colonization. The therapeutic implication of these findings is discussed.

In vitro antimicrobial sensitivity of enteric rods and pseudomonads from advanced adult periodontitis

The prevalence and in vitro antimicrobial sensitivity of isolates of enteric rods and pseudomonads was examined in 844 adult periodontitis patients. These organisms were recovered from 13.5% of the study subjects. Ciprofloxacin exhibited the highest inhibitory activity of the 14 oral antimicrobial agents tested. Beta-lactam antibiotics were largely ineffective, and tetracycline failed to inhibit most Pseudomonas species. In vitro sensitivity data suggest that a subgingival microbiota comprising mainly streptococci would result from therapy that combined ciprofloxacin and metronidazole. Since streptococci may inhibit the growth of several putative periodontal pathogens, populations of "beneficial" streptococci in the periodontal pocket might constitute a very attractive therapeutic outcome. Controlled clinical studies are needed to clarify the possible role of ciprofloxacin in the treatment of destructive periodontitis.

Antibiotics in periodontal therapy: advantages and disadvantages

Antibiotic treatment of periodontitis aims at eradicating or controlling specific pathogens. Prime candidates for antibiotic therapy are patients with recently diagnosed active periodontitis or a history of recurrent disease who fail to stabilize following mechanical/surgical therapy. Since a variety of microbes with differing antimicrobial susceptibility profiles may cause periodontitis, selection of antimicrobial agents should be based on proper microbial diagnosis and sensitivity testing, as well as consideration of the patient's medical status. The risk of treating chemotherapeutically solely on the basis of clinical features, radiographic findings or a limited microbiological analysis, is failure to control the pathogens or overgrowth of new pathogens. A review of published papers reveals that appropriate systemic antibiotic therapy may enhance healing in patients with recent or high risk of periodontal breakdown. Systemic antibiotic therapy seems more predictable than topical administration in eradicating periodontal pathogens from deep periodontal pockets. Several promising antimicrobial agents for periodontitis treatment need testing in placebo-controlled, double-blind, randomized clinical trials.

Leukocidal activity of staphylococci isolated from human periodontal lesions

Staphylococci isolated from subgingival samples of patients with advanced periodontitis were tested for leukocidal activity. Intact organisms, bacterial sonicates or bacterial culture supernatants were incubated with human neutrophils that had been prelabeled with 51chromium. The majority of Staphylococcus aureus periodontal isolates provoked dose-dependent extracellular release of the radiolabel. By contrast, other strains of staphylococci had marginal or no demonstrable leukocidal activity. Leukocidal activity was heat-sensitive and was neutralized by horse anti-leukocidin antibodies. The results indicate that S. aureus colonizing human periodontal lesions elaborate a leukocidin that may conceivably destroy neutrophils that emigrate into the gingival region. This could adversely affect the overall status of this antimicrobial defense system in the gingival area and contribute to the pathogenicity of S. aureus as well as other potential periodontopathic organisms.

5-year follow up of periodontal intraosseous defects treated by root planing or flap surgery

Intraosseous, periodontal defects in 12 subjects initially treated by root planing alone (21 defects) or by flap surgery (21 defects) were monitored during a 5-year postoperative interval. Maintenance therapy during this interval was limited to reinforcement of oral hygiene and tooth polishing every 6 months. No subgingival instrumentation was performed at the defect sites. Longitudinal clinical measurements demonstrated that surgically-treated lesions responded with somewhat more reduction of probing depth and more gain of probing bone level than root-planed lesions. Mean gains of probing attachment level were similar for the 2 treatments. Some relapse of the clinical conditions could be observed towards the end of the 5-year observation interval compared to the results at year 1 and year 2. However, the majority of defects subjected to either treatment showed 60-month recordings of probing attachment and probing bone levels equal to or slightly improved compared to those at baseline. Counts from cultures of subgingival, microbial samples were obtained at 42, 48 and 60 months. No significant difference between the 2 therapies was observed for the investigated groups of micro-organisms.

Effect of root debridement on the elimination of Actinobacillus actinomycetemcomitans and Bacteroides gingivalis from periodontal pockets

The aims of this 6-month longitudinal study were: (1) to investigate to what extent root debridement of pockets in adult periodontitis will reduce the subgingival presence of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and some other bacterial groups; (2) to relate the microbiological results following debridement to clinical measurements of healing. 16 patients and a total of 111 periodontally involved sites with probing depth greater than or equal to 6 mm served for the study. Duplicate subgingival microbial samples and duplicate clinical recordings were obtained 1 week apart at baseline and at 6 months following supra- and subgingival debridement. The results demonstrated reductions of the mean total viable counts and reductions of the mean counts of several of the cultured groups of micro-organisms coupled with significant improvements of mean clinical measurements. B. gingivalis was eliminated from a majority of infected subgingival sites. A. actinomycetemcomitans, on the other hand, still remained after therapy in a high proportion of sites initially infected with this microorganism. Subgingival persistence of A. actinomycetemcomitans appeared to be associated with a reduced healing response following debridement. Further studies are needed to clarify why A. actinomycetemcomitans is poorly eliminated following debridement. Also, the long-term clinical significance of the subgingival perseverance of A. actinomycetemcomitans needs to be elucidated.

On the inability of root debridement and periodontal surgery to eliminate Actinobacillus actinomycetemcomitans from periodontal pockets

In a previous study, we observed that root debridement was inefficient in eliminating Actinobacillus actinomycetemcomitans from adult periodontitis lesions. The present report describes the effects on A. actinomycetemcomitans of subsequent treatments of 6 patients that had at least 2 separate sites still harboring A. actinomycetemcomitans 6 months following debridement. 1 site or more in each individual was treated with renewed root debridement and at least 1 other site was treated by surgical excision of the gingival tissue. The results indicated that retreatment with either repeated root debridement or with surgical excision of the gingival tissue was not more effective in eliminating A. actinomycetemcomitans than initial debridement. The possible reasons for this limited therapeutic effect on the subgingival presence of A. actinomycetemcomitans are discussed.

Subgingival occurrence of enteric rods, yeasts and staphylococci after systemic doxycycline therapy

The occurrence of subgingival enteric rods, yeasts and staphylococci (pre-treatment and post-treatment) was examined in 21 adult periodontitis patients receiving mechanical periodontal therapy and systemic doxycycline (200 mg on first day, then 100 mg/day for 20 days). Subgingival samples obtained prior to, and 2 weeks and 4 weeks after completion of the antibiotic therapy were transported in VMGA III and plated onto TSBV (for enteric rods and yeasts) and Staphylococcus 110 media. At baseline, small numbers of enteric rods (3 patients), yeasts (5 patients) and staphylococci (11 patients) were detected subgingivally. After the antibiotic therapy, more than 10-fold increases were seen in subgingival numbers of Enterobacter aerogenes (2 patients), Escherichia coli (1 patient), Candida albicans (2 patients), and staphylococci (11 patients). These findings demonstrating that systemic doxycycline therapy may result in at least temporary subgingival overgrowths of enteric rods, yeasts and staphylococci, may indicate the risk of frequent use of tetracycline in periodontal therapy.

Prevalence and antimicrobial susceptibility of Enterobacteriaceae, Pseudomonadaceae and Acinetobacter in human periodontitis

This study examined the occurrence of non-oral gram-negative facultatively anaerobic rods in advanced adult periodontitis. Speciation and in vitro antimicrobial susceptibility testing was performed using the MicroScan micromethod system. A total of 42 taxa of Enterobacteriaceae, Pseudomonadaceae and Acinetobacter were isolated from 427 of 3,050 (14.0%) patients. In 159 (5.2%) patients, these organisms comprised more than 5% of the cultivable subgingival microflora. Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Klebsiella oxytoca and Enterobacter agglomerans accounted for more than 50% of all strains isolated. Virtually all study strains demonstrated high in vitro susceptibility to ciprofloxacin, but exhibited variable susceptibility patterns to 18 other antimicrobial agents tested. In 3 "refractory" periodontitis patients heavily infected with enteric rods, systemic ciprofloxacin therapy (500 mg BiD for 10 days) led to resolution of the subgingival infections and improved clinical periodontal status. The present findings indicate that 5% of severe periodontitis lesions may harbor high levels of non-oral, gram-negative, facultatively anaerobic rods. Systemic ciprofloxacin appears to be capable of eradicating these potential pathogens from deep periodontal pockets.