Generalized juvenile periodontitis, defective neutrophil chemotaxis and Bacteroides gingivalis in a 13-year-old female. A case report

Electronic Cigarette Aerosol Modulates the Oral Microbiome and Increases Risk of Infection

The trend of e-cigarette use among teens is ever increasing. Here we show the dysbiotic oral microbial ecology in e-cigarette users influencing the local host immune environment compared with non-smoker controls and cigarette smokers. Using 16S rRNA high-throughput sequencing, we evaluated 119 human participants, 40 in each of the three cohorts, and found significantly altered beta-diversity in e-cigarette users (p = 0.006) when compared with never smokers or tobacco cigarette smokers. The abundance of Porphyromonas and Veillonella (p = 0.008) was higher among vapers. Interleukin (IL)-6 and IL-1β were highly elevated in e-cigarette users when compared with non-users. Epithelial cell-exposed e-cigarette aerosols were more susceptible for infection. In vitro infection model of premalignant Leuk-1 and malignant cell lines exposed to e-cigarette aerosol and challenged by Porphyromonas gingivalis and Fusobacterium nucleatum resulted in elevated inflammatory response. Our findings for the first time demonstrate that e-cigarette users are more prone to infection.

Comparison of CCL28, interleukin-8, interleukin-1β and tumor necrosis factor-alpha in subjects with gingivitis, chronic periodontitis and generalized aggressive periodontitis

BACKGROUND AND OBJECTIVE

Cytokines produced by various cells are strong local mediators of inflammation. Mucosa-associated epithelial chemokine (CCL28), interleukin-8 (IL-8), interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) are major cytokines that play important roles in the periodontal inflammatory process. In this study we aimed to compare the levels of CCL28, IL-8, IL-1β and TNF-α in the gingival crevicular fluid of both periodontally healthy subjects and in subjects diagnosed with gingivitis, chronic periodontitis and generalized aggressive periodontitis.

MATERIAL AND METHODS

A total of 84 subjects participated in the study: 21 subjects had gingivitis, 21 subjects had chronic periodontitis, 21 subjects had generalized aggressive periodontitis and 21 were periodontally healthy. The levels of CCL28, IL-8, IL-1β and TNF-α were analyzed using enzyme-linked immune sorbent assay (ELISA).

RESULTS

The total levels of CCL28 and IL-8 in the gingival crevicular fluid of the generalized aggressive periodontitis group (324.74 ± 42.62 pg/30 s, 487.62 ± 49.21 pg/30 s) were significantly higher than those of the chronic periodontitis group (268.81 ± 28.64 pg/30 s, 423.65 ± 35.24 pg/30 s), the gingivitis group (146.35 ± 17.46 pg/30 s, 310.24 ± 48.20 pg/30 s) and the periodontally healthy group (92.46 ± 22.04 pg/30 s, 148.41 ± 24.64 pg/30 s). Similarly, the total levels of IL-1β and TNF-α in the generalized aggressive periodontitis group (110.23 ± 9.20 pg/30 s, 1284.46 ± 86.32 pg/30 s) were significantly higher than those in the chronic periodontitis group (423.65 ± 35.24 pg/30 s, 82.64 ± 9.12 pg/30 s), the gingivitis group (52.10 ± 7.15 pg/30 s, 824.24 ± 44.68 pg/30 s) and the periodontally healthy group (36.44 ± 8.86 pg/30 s, 628.26 ± 34.61 pg/30 s).

CONCLUSION

CCL28, IL-8, IL-1β and TNF-α may play key roles in the host response to inflammation in periodontal diseases. As the severity of periodontal diseases increases, destruction of periodontal tissues also increases. Inflammation is one among many factors that trigger periodontal tissue destruction. Identification of the mediators that influence the development and progression of inflammation in periodontal diseases may be very important in understanding the prognoses of periodontal diseases.

Hemagglutinin B is involved in the adherence of Porphyromonas gingivalis to human coronary artery endothelial cells

Porphyromonas gingivalis is a periodontopathogen that may play a role in cardiovascular diseases. Hemagglutinins may function as adhesins and are required for virulence of several bacterial pathogens. The aim of this study was to determine the role of hemagglutinin B (HagB) in adherence of P. gingivalis to human coronary artery endothelial (HCAE) cells. P. gingivalis strain 381, a P. gingivalis 381 HagB mutant, Escherichia coli JM109 expressing HagB (E. coli-HagB), and E. coli JM109 containing pUC9 (E. coli-pUC9) were tested for their ability to attach to HCAE cells. Inhibition assays were performed to determine the ability of purified recombinant HagB (rHagB) as well as antibodies to HagB, including the polyclonal antibody (PAb) A7985 and the monoclonal antibody (MAb) HL1858, to inhibit the attachment of P. gingivalis to HCAE cells. As expected, when the attachment of P. gingivalis and the HagB mutant were compared, no statistical significance was observed between the two groups (P = 0.331), likely due to the expression of the hagB homolog hagC. However, E. coli-HagB adhered significantly better to HCAE cells than did E. coli-pUC9, the control strain. In a competition assay, the presence of purified rHagB decreased bacterial adhesion of P. gingivalis or E. coli-HagB to HCAE cells. The presence of PAb A7985 or MAb HL1858 also significantly decreased attachment of P. gingivalis and E. coli-HagB to host cells. These results indicate that HagB is involved in the adherence of P. gingivalis to human primary endothelial cells.

Position paper: periodontal diseases of children and adolescents

Children and adolescents are subject to several periodontal diseases. Although there is a much lower prevalence of destructive periodontal diseases in children than in adults, children can develop severe forms of periodontitis. In some cases, this destructive disease is a manifestation of a known underlying systemic disease. In other young patients, the underlying cause for increased susceptibility and early onset of disease is unknown. These diseases are often familial, suggesting a genetic predisposition for aggressive disease. Current modalities for managing periodontal diseases of children and adolescents may include antibiotic therapy in combination with non-surgical and/or surgical therapy. Since early diagnosis ensures the greatest chance for successful treatment, it is important that children receive a periodontal examination as part of their routine dental visits.

Absence of a specific subgingival microflora in adults with Down's syndrome

BACKGROUND

Periodontal disease in Down's syndrome (DS) is generally characterized by a high degree of bone loss. Bone loss of 5 mm or more is observed in 70% of these subjects. Among DS subjects, considerable differences in disease progression occur. So far, no studies have been conducted in which specific properties of the subgingival microflora have been related to the condition observed.

AIMS

To investigate (1) the subgingival microflora in DS subjects and other mentally retarded (control) individuals which were matched to the utmost and (2) to investigate the subgingival microflora of a "low-risk" and a " high-risk" group formed in DS subjects.

MATERIAL AND METHODS

17 DS subjects and 17 control subjects were matched with respect to age, plaque level and bleeding on probing. In addition, the DS group was divided in a "low-risk" group (0-2 teeth lost due to periodontal disease n=6) and a "high-risk"group (6-13 teeth lost due to periodontal disease n=11). Prevalence and proportions of the putative periodontal pathogens Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Peptostreptococcus micros, Fusobacterium nucleatum and Campylobacter rectus in the subgingival plaque were determined using anaerobic culture techniques. No differences in the prevalence of distinct suspected periodontopathic bacteria and bacterial subgingival composition between the DS group and the control group could be established. Also no differences in the prevalence of the seven investigated microbial species between the "low-risk" and the "high-risk" group were observed.

CONCLUSIONS

Because of the lack of differences in microflora between the DS group and the control group, a specific effect of the microbiological composition in the periodontal status of subjects with DS can be excluded in this population. Host factors constitute the more likely explanation of the differences observed in DS.

Inhibition of Actinobacillus actinomycetemcomitans leukotoxicity by bacteria from the subgingival flora

Actinobacillus actinomycetemcomitans produces a pore-forming leukotoxin that lyses human polymorphonuclear leukocytes and monocytes. Certain proteolytic bacteria may coexist with A. actinomycetemcomitans in periodontal pockets. We aimed therefore to examine whether oral bacteria can modify the leukotoxicity of A. actinomycetemcomitans. A total of 55 strains representing 45 bacterial species of the subgingival flora were tested. Each strain was incubated with the highly toxic strain of A. actinomycetemcomitans HK 1519 and the leukotoxic activity of the suspension against human polymorphonuclear leukocytes was determined from the activity of the lactate dehydrogenase released upon lysis of the leukocytes. Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Prevotella melaninogenica and Prevotella loeschii inhibited the leukotoxicity of A. actinomycetemcomitans cells as well as the activity of leukotoxin purified from the same strain. The bacterial strains without the ability to block leukotoxic activity also failed to destroy pure leukotoxin even after 5 h of incubation. The proteolytic degradation of leukotoxin by P. gingivalis was mainly dependent on the activity of the enzymes R- and K-gingipains. P. intermedia and P. nigrescens also degraded the leukotoxin by enzymes. The results imply a role of the periodontal microflora in modifying the virulence of A. actinomycetemcomitans by destroying its leukotoxin.

Occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in juvenile periodontitis

The occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in subgingival plaque in 24 juvenile periodontitis patients was determined using DNA probe. 36 samples of subgingival plaque from 36 pockets having > or = 6 mm depth, > or = 3 mm of loss of attachment, and bleeding on probing and/or suppuration were taken from 18 patients with localized juvenile periodontitis (LJP, age range 12-24 years); and 12 samples from 6 patients with generalized juvenile periodontitis (GJP, age range 23-26 years). As control, an equal numbers of samples from healthy sites in the same patients were studied. P. gingivalis was found in 17 of 18 LJP patients, and in 31 of 36 diseased sites in those patients. P. intermedia was found in 15 out of the 18 LJP patients and in 28 of the 36 diseased sites. A. actinomycetemcomitans was present in 7 of the 18 LJP patients, and in 9 of the 36 diseased sites, and was not found in any GJP patients. All GJP patients had P. gingivalis (11 out of 12 diseased sites) and P. intermedia (all of the diseased sites). None of the three bacterial species was detected in healthy sites of GJP patients, and were found in healthy sites in only 2 of 18 LJP patients. The high prevalence and high levels of P. gingivalis and P. intermedia found in the LJP and GJP patients studied, suggest that there are populations affected by juvenile periodontitis in which this type of periodontitis is more associated with these species than with A. actinomycetemcomitans.

Occurrence of certain bacterial species and morphotypes in juvenile periodontitis in Chile

The occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, Fusobacterium nucleatum, Campylobacter rectus, Capnocytophaga species, and certain bacterial morphotypes was determined in 18 affected and 18 unaffected sites in 10 localized juvenile periodontitis (LJP) patients, and in 10 affected and 10 unaffected sites in 5 generalized juvenile periodontitis (GJP) patients. The subgingival proportion of the 7 bacterial species was determined by selective and nonselective culturing. The results showed that when considering the pure prevalence of bacteria ( > 0%) there were significant differences (P < 0.05) in the subgingival plaque microflora of the affected sites versus those of the unaffected sites for P. gingivalis, A. actinomycetemcomitans, P. intermedia, E. corrodens, C. rectus, and F. nucleatum in LJP, and for P. gingivalis, P. intermedia, and F. nucleatum in GJP. The mean proportions of cocci, motile rods and spirochetes were also significantly different (P < 0.05) in affected sites compared to unaffected sites. Capnocytophaga sp, F. nucleatum, P. intermedia, and E. corrodens were found in more than 75% of affected sites in LJP. When taking the approach that an organism, to be associated with periodontal disease, has to be detected above a certain minimum threshold, the results indicated that bacteria most frequently associated with LJP and GJP in Chile are P. gingivalis (66% of LJP and 80% of GJP affected sites), and A. actinomycetemcomitans (44% of LJP and 50% in GJP affected sites). Different bacterial species may be judged to be important in the disease process depending upon whether a pure bacterial prevalence, or a prevalence above a certain detection level, is considered.

The vascular response in chronic periodontitis

The role of vascular endothelial cells (EC) in periodontitis was investigated in a series of histological studies. Expansion of the vasculature was found to occur with development of gingivitis and periodontitis. This was thought to contribute to the characteristic tissue degradation in the developing disease. Vascular expansion could also play a role in the formation of a previously unreported perivascular hyaline material (PHyM). Polymorphonuclear leukocytes (PMN) are known to be protective in periodontitis, and the location, incidence and extent of PHyM suggested a role for PHyM in periodontitis by inhibiting PMN emigration. PMN emigration was found to occur from specialized high EC (HEC) lined post capillary venules. This was unexpected, as such vessels have previously been found to exchange lymphocytes almost exclusively. Detailed histochemical, ultrastructural and biosynthetic studies of these specialized blood vessels led to the suggestion that HEC may be specially adapted for the synthesis of cytokines in periodontitis. A negative association between expression of the membrane bound ectoenzyme, alkaline phosphatase, and HEC suggested a role for this enzyme in leukocyte emigration. These observations compel re-evaluation of the role of EC in chronic inflammation, and in periodontitis in particular. The direction of current and future work is discussed.

Epidemiology and transmission of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans among children and their family members. A report of 4 surveys

The distribution and transmission of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in 4 families were studied. The families were included, based on the isolation of P. gingivalis from a young child or adolescent. The probands of these 4 families were: a 5-year old periodontally healthy boy; a 17-year old girl with severe generalized juvenile periodontitis; an 11-year old girl with prepubertal periodontitis; 2 sisters, 5 and 17-years old, with untreated severe periodontitis as a component of the Papillon-Lefèvre syndrome. All members of the 4 families were examined clinically and microbiologically for the presence of P. gingivalis and A. actinomycetemcomitans. Most of the parents appeared to be adult periodontitis patients; the parents of one proband were edentulous. Results showed that in all cases at least one of the parents was positive for P. gingivalis. On the basis of indistinguishable restriction endonuclease patterns (REPs) of P. gingivalis and A. actinomycetemcomitans isolates from parents and their children, and distinct REPs from unrelated individuals, the present study indicates that P. gingivalis and A. actinomycetemcomitans were transmitted between parents and their children.

Suppression of subgingival Actinobacillus actinomycetemcomitans in localized juvenile periodontitis by systemic tetracycline

The current study assessed the clinical and microbiological effects of systemic antimicrobial therapy alone in Actinobacillus actinomycetemcomitans-infected adolescents with periodontal disease. The study involved 6 localized juvenile periodontitis patients 13-18 years of age, who harbored high numbers of A. actinomycetemcomitans in subgingival plaque samples. The periodontal lesions were microbiologically monitored by selective culture, and clinically assessed for probing pocket depth and periodontal attachment level 3 months prior to baseline, and at 3, 6, 12, and 24 months posttreatment. Tetracycline-HCl (250 mg/QID) was prescribed until 1 week after subgingival A. actinomycetemcomitans was no longer detectable or for a maximum of 8 weeks. During 3 months prior to treatment, pocket depth was unchanged, and was then significantly reduced from an average of 7.1 mm to 5.1 mm 12 months after treatment (p = 0.02). The mean change in clinical attachment level was a gain of 1.4 mm between baseline and 12 months (p = 0.02). 3 of the 6 patients were still infected with A. actinomycetemcomitans after 8 weeks of antibiotic therapy and 4 subjects were infected at 12 months. Numbers of A. actinomycetemcomitans were still suppressed in most lesions. There was a strong association between mean numbers of A. actinomycetemcomitans in periodontal pockets and mean change in probing attachment level at any given time point. For 22 available comparisons, derived from all time points, there was a strong association (r = 0.68) between subgingival A. actinomycetemcomitans and change in probing attachment level.(ABSTRACT TRUNCATED AT 250 WORDS)

Neutrophil modulation by Actinobacillus actinomycetemcomitans. II. Phagocytosis and development of respiratory burst

Compromised neutrophil function has been found in a number of patients with localized juvenile periodontitis (LJP), although the pathogenic mechanism is unknown. Since infection with Actinobacillus actinomycetemcomitans is frequently found in patients with LJP, we have evaluated in vitro the effect of a bacterial extract of A. actinomycetemcomitans on the development of the respiratory burst by neutrophils. Pre-incubation of neutrophils with bacterial extract increased H2O2 induced by FMLP and zymosan in a dose-dependent fashion. Substitution of FMLP for bacterial extract produced similar results. Moreover, FMLP and bacterial extract had an additive effect on superoxide production following phagocytosis of zymosan. In contrast, bacterial extract significantly decreased PMA-stimulated H2O2, but pre-incubation with FMLP instead of bacterial extract failed to decrease PMA-stimulated H2O2. Bacterial extract did not change the percentage of cells activated by FMLP, opsonized zymosan, or PMA. Heat-treated bacterial extract induced effects similar to non-treated extract. Bacterial extract treated with proteinase K or phenol extraction increased FMLP or zymosan stimulated H2O2 equivalent to non-treated bacterial extract. In contrast, proteinase K or phenol extraction abolished the inhibitory effect of bacterial extract on PMA-stimulated H2O2 production. The bacterial extract component(s) that inhibits PMA-stimulated H2O2 is therefore a protein(s), resistant to 56 degrees C, and is not endotoxin. The partially activated state of PMNs exposed to A. actinomycetemcomitans extract, combined with their reduced ability to respond to a protein kinase C-dependent stimulus, may partially explain the abnormalities noted in LJP patients.

Chronic adult periodontitis and burst progression may reflect local neutrophil defects due to perivascular hyaline deposits

Chronic adult periodontitis (CAP) is a common disease of the supporting tissues of teeth, and is a major cause of tooth loss. This disease is distinguished from more rare rapidly progressing forms of periodontitis, in which a variety of neutrophilic polymorphonuclear leukocyte (PMN) defects have been identified. PMN dysfunctions have, however, not been observed in CAP. In CAP, destructive episodes of the disease occur sporadically and independently in different parts of the mouth. In this paper, it is proposed that CAP is due to highly localized defects in PMN function. Impaired PMN function is suggested as resulting in the formation of a virulent bacterial plaque, which is capable of initiating periodontal pocket formation. A previously reported perivascular hyaline material may account for localized PMN defects, by reducing the number of PMNs entering affected sites. The proposed model may explain both the presence of CAP in otherwise normal patients, and the sporadic pattern of tissue destruction seen in this disease.

Generalized juvenile periodontitis: report of a familial case followed for 5 years

The case of a family, followed for 5 years and showing an exceptionally high prevalence of Generalized Juvenile Periodontitis (GJP), is presented. Two siblings were affected by a severe form of GJP meanwhile the dycorial twin of one was periodontally healthy. Both the affected siblings showed infection by Actinobacillus actinomycetemcomitans (Aa), but only one presented a reduced chemotaxis of the peripheral PMNs. The dycorial twin consistently displayed a freedom from Aa and a reduction in the peripheral PMNs chemotaxis. The extraction of the compromised teeth in the two affected siblings has been followed by colonization of new sites by Aa; only repeated administration of systemic tetracyclines seems to protect the subjects from colonization of other sites. These findings may contribute to the understanding of the etiology, pathogenesis, and therapy of juvenile periodontitis.

Opsonic IgG antibody against Actinobacillus actinomycetemcomitans in localized juvenile periodontitis

Actinobacillus actinomycetemcomitans is a gram-negative bacterium frequently recovered from periodontal lesions of patients with localized juvenile periodontitis (LJP). Elevated levels of serum IgG and IgM antibodies to A. actinomycetemcomitans antigens are frequently observed in LJP patients, although the functional properties of such antibodies have not been characterized systematically. In this study, we analyzed serum from LJP subjects infected with A. actinomycetemcomitans with respect to the presence of IgG antibodies expressing opsonic, bactericidal and/or leukotoxin-neutralizing activity against this organism. The IgG fractions obtained from serum of 3 LJP patients with elevated antibody titers to A. actinomycetemcomitans contained opsonic activity against a non-leukotoxic Y4 strain, as well as for a highly leukotoxic JP2 strain. Opsonic activity required the presence of complement. The IgG fractions of pooled normal serum and serum from a fourth LJP subject with minimal ELISA-reactive IgG antibody against this organism lacked detectable opsonic activity. Leukotoxin-neutralizing IgG antibodies, although variably present, did not influence neutrophil killing of the leukotoxic JP2 strain. None of the sera tested contained bactericidal IgG antibodies capable of promoting direct complement-mediated killing of A. actinomycetemcomitans. These results indicate that LJP subjects infected with A. actinomycetemcomitans are capable of producing opsonic IgG antibodies which may facilitate neutrophil-mediated host defense against this periodontopathic organism.

The effect of 2% chlorhexidine digluconate irrigation on clinical parameters and the level of Bacteroides gingivalis in periodontal pockets

Eight patients with moderate periodontitis volunteered to participate in a study to assess the effect of subgingival 2% chlorhexidine irrigation, with and without scaling and root planing, on clinical parameters and the level of Bacteroides gingivalis in periodontal pockets. Each quadrant was required to have at least one site with a probing depth of 6 mm or greater and bleeding on probing. The patients were treated following a randomized four quadrant design: one quadrant received no treatment; a second quadrant received scaling and root planing only; a third quadrant received chlorhexidine irrigation only; the fourth quadrant received scaling and root planing, plus chlorhexidine irrigation. Sites to receive chlorhexidine were irrigated at 0, 1, 2, and 3 weeks. Clinical and microbiological indices were measured and recorded at 0, 5, 7, 11, and 15 weeks. The clinical parameters measured included; Plaque Index (PI), Gingival Index (GI), probing depth (PD), Bleeding Tendency (BT), and attachment level (AL). The attachment level was measured using an occlusal stint as a fixed reference point. The level of Bacteroides gingivalis was measured by labeling the plaque sample with a polyclonal fluorescent antibody. The plaque smear was then read using a fluorescent microscope at 1000 magnification. The Spearman Rank-Order Correlation was used to determine the relationship between parameters at baseline. The effects of the treatment groups were compared using the Neuman-Keuls Multiple Comparison Technique. The results showed that a positive correlation existed between B. gingivalis (rs = 0.68) and Bleeding Tendency and between P1I (rs = 0.77) and GI.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring of subgingival Bacteroides gingivalis and Actinobacillus actinomycetemcomitans in the management of advanced periodontitis

In a series of clinical trials involving 79 adult periodontitis patients, we evaluated the clinical and microbiological effects of H2O2, NaHCO3, and a commercially available povidine solution, as adjuncts to mechanical periodontal debridement. Each trial included a placebo as a control. The healing response was monitored clinically by measurement of changes in probing attachment levels after treatment. The current report includes data from single-rooted teeth only.

In general, healing in severely advanced periodontal lesions (initial pocket depth ≥ 7 mm) was enhanced by the use of the listed topical antimicrobial agents administered subgingivally during mechanical debridement.

Correlations were sought between changes in probing attachment levels 12 months after treatment, and the presence of subgingival B. gingivalis and A. actinomycetemcomitans in the periodontal lesions. For a total of 428 lesions included in this report, B. gingivalis was detected in 53.1% of lesions showing probing attachment loss (≥1.5 mm), but in only 4.7% of lesions showing gain (≥ 1.5 mm). Either B. gingivalis or A. actinomycetemcomitans was detected in 70.1% of the lesions showing loss and in only 4.8% of those showing gain. These studies indicate the benefits of the adjunctive antimicrobial therapy described, and the usefulness of specific microbiological monitoring as an aid to clinical measurements in the evaluation of success or failure of treatment of chronic adult periodontitis.

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans in human periodontal diseases

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans seem to be major pathogens in advancing periodontitis in man. First, these organisms are recovered in higher prevalence and proportions from progressive periodontitis lesions than from quiescent periodontal sites. Second, antibody levels against B. gingivalis and A. actinomycetemcomitans are markedly elevated in serum and gingival crevice fluid of periodontitis patients compared to normal controls. Third, B. gingivalis and B. intermedius elaborate potent proteases and A. actinomycetemcomitans various noxious substances which have the potential to perturb important host defenses and to disintegrate key constituents of the periodontal tissues. Monitoring these bacteria in advanced periodontal lesions may greatly assist the assessment of treatment efficacy and risk of further periodontal breakdown.

Tissue localization of Actinobacillus actinomycetemcomitans in human periodontitis. II. Correlation between immunofluorescence and culture techniques

Recent immunohistological studies have suggested that Actinobacillus actinomycetemcomitans is present in the gingival tissues in juvenile periodontitis lesions. The present study examined tissue bound A. actinomycetemcomitans by bacterial culture and immunohistological demonstration of antigen in tissue. A total of 14 periodontitis lesions were examined. Eleven biopsies were obtained from gingiva adjacent to A. actinomycetemcomitans infected pockets, while the remaining three control biopsies were obtained from gingiva adjacent to pockets where subgingival A. actinomycetemcomitans infection could not be detected. Each biopsy was hemisected, one half was used for immunofluorescence microscopic examination while the other half was processed for culture of A. actinomycetemcomitans. The latter section was surface-disinfected, repeatedly washed and then minced to release bacteria from within the tissues. Aliquots from the serial washings and the minced tissue suspension were cultured on medium selective for A. actinomycetemcomitans. Surface disinfection and serial washings gradually decreased cultivable A. actinomycetemcomitans in the washings aliquots. Following tissue disruption, an increase in colony-forming units of A. actinomycetemcomitans was seen from eight of the 11 test biopsies. This bacterium could not be detected in washings or minced tissue suspensions from the control biopsies obtained from lesions in which subgingival A. actinomycetemcomitans was previously not detected. A positive correlation was seen between the presence of A. actinomycetemcomitans antigens in the gingival biopsies and; (1) A. actinomycetemcomitans colony-forming units released from the minced tissues (r = 0.90, p = 0.000), as well as; (2) the colony-forming units from the periodontal pocket (r = 0.62, P = 0.017).(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification of the bacterium Bacteroides gingivalis in human dental plaque by detection of the trypsin-like protease activity of colonies imprinted on membrane filters

Individual colonies of this organism in primary cultures of human dental plaque were distinguished from colonies of other species of black-pigmented Bacteroides by detection of their trypsin-like proteolytic activity using a specific chromogenic enzyme substrate.

Occurrence and appearance of cementum hypoplasias in localized and generalized juvenile periodontitis

The occurrence and appearance of cementum hypoplasias have been studied on teeth affected by juvenile periodontitis. Scanning electron microscopy showed the presence of cementum hypoplasias on the root surface of all extracted first molars and one incisor from nine patients with localized juvenile periodontitis and on most extracted teeth from two patients with generalized juvenile periodontitis. No hypoplasias were found on the extracted third molars. The alveolar bone loss in these patients seemed to be correlated to the frequency and extension of the hypoplastic areas in the associated teeth. The distribution of the teeth affected by localized juvenile periodontitis showed a symmetric distribution in the jaws. The patients with generalized juvenile periodontitis showed considerable deposits of dental calculus and wide areas of root resorption. The disturbance of cementum formation may have been caused by hereditary systemic factors, which subside with increasing age of the patient. The clinical appearance of juvenile periodontitis may therefore be influenced by the age at onset, the duration, and the frequency of such systemic factors, giving rise to a localized form and a more generalized form. One such factor may be a varying degree of hypophosphatasia.

Report of Committee on Scientific Investigation of the American Academy of Restorative Dentistry

A few personal points seem appropriate in summary. It is axiomatic that while research solves problems, it also creates them. As an example, it is an accepted fact that dentistry more than any other profession has made serious inroads into putting itself out of business through research. Each year this report takes note of the reduction in dental caries in children, which has thus triggered a change in the nature of general practice. Be this as it may, it is well to acknowledge that major dental diseases are not disappearing, but their patterns in the population are changing, accompanied by an expansion of other services. Despite the optimistic picture painted earlier in this report, it is grossly premature to acclaim the elimination of caries, and thereby a significant segment of restorative dentistry. Of course the younger age groups have been the major beneficiaries of caries reduction. As the child ages from 9 to 16 years, the percentage of mouths free of caries drops by one half. In addition, the disease pattern in the adult population is being altered because of a longer life span and loss of fewer teeth. Unquestionably what we will, and are already seeing, is not an elimination of restorative dentistry but a different target and changes in procedures because of new materials, therapy, and expanded scope of services. There is yet another subtle change in the trend of dental research and it deals with the reduction in the number of dental schools worldwide and smaller class sizes in those schools. Dental research thereby suffers because of the traditional link between education and research. Thus the potential pool of researchers becomes smaller and research monies for training programs for dental investigators, particularly in clinical research, decreases. This year a surprising number of articles are concerned with manpower as it relates to research priorities. So, it is indeed a time that both the profession and the scientific community find filled with controversy and frustration. Yet never has there been a time that offers more in challenges and rewards.