RESUMEN
Periodontal regeneration-treatment that results in new alveolar bone, cementum, and a functional periodontal ligament-is successful in class II furcation defects. This article examines one aspect of periodontal regeneration-alveolar bone growth in furcation defects-in trying to answer the question, Can bone lost from furcations be regenerated? The best evidence for bone growth is histology but there is limited histologic evidence for bone growth in human furcation defects. There is more evidence from intraoperative measurements for hard tissue growth in treated furcation defects, but the nature of the hard tissue needs to be determined histologically.
Asunto(s)
Pérdida de Hueso Alveolar , Regeneración Ósea , Defectos de Furcación , Regeneración Tisular Guiada Periodontal , Animales , HumanosRESUMEN
BACKGROUND: Triclosan is a broad-spectrum antimicrobial agent used in toothpaste to reduce dental plaque, gingivitis and oral malodor. This community-level assessment evaluated the susceptibility of dental plaque bacteria to triclosan in samples collected over 19 years. METHODS: A total of 155 dental plaque samples were collected at eleven different times over 19 years from 58 adults using 0.3% triclosan, 2% copolymer, 0.243% sodium fluoride toothpaste and from 97 adults using toothpaste without triclosan. These included samples from 21 subjects who used triclosan toothpaste for at least five years and samples from 20 control subjects. The samples were cultured on media containing 0, 7.5 or 25 µg/ml triclosan. Descriptive statistics and p values were computed and a linear regression model and the runs test were used to examine susceptibility over time. RESULTS: Growth inhibition averaged 99.451% (91.209 - 99.830%) on media containing 7.5 µg/ml triclosan and 99.989% (99.670 - 100%) on media containing 25 µg/ml triclosan. There was no change in microbial susceptibility to triclosan over time discernible by regression analysis or the runs test in plaque samples taken over 19 years including samples from subjects using a triclosan-containing dentifrice for at least five years. CONCLUSIONS: This community-level assessment of microbial susceptibility to triclosan among supragingival plaque bacteria is consistent with the long-term safety of a 0.3% triclosan, 2% copolymer, 0.243% sodium fluoride dentifrice.
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Antiinfecciosos Locales/uso terapéutico , Bacterias/efectos de los fármacos , Placa Dental/microbiología , Farmacorresistencia Bacteriana , Triclosán/uso terapéutico , Adulto , Carga Bacteriana , Técnicas Bacteriológicas , Cariostáticos/uso terapéutico , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana , Fluoruro de Sodio/uso terapéutico , Pastas de Dientes/uso terapéuticoRESUMEN
OBJECTIVE: Dental implants and peri-implant tissue are susceptible to disease conditions that may lead to implant loss. The objective of the present study was to describe teeth and implant surroundings as well as clinical health indices and oral microbiologic parameters. METHOD AND MATERIALS: A group of 83 adults (42 men and 41 women) were enrolled in the study. Clinical assessments of dental implants and contralateral natural teeth included dental plaque, gingival inflammation, and bleeding on probing. Microbiologic assessments included bacterial culture, light and phase contrast microscopy, and DNA probe hybridization for a panel of 14 target microorganisms. Clinical and microbiologic data were compared by paired t test and ANOVA. P < .05 was considered statistically significant. RESULTS: The Plaque Index for the implants was 1.85 ± 0.47, whereas the score for natural teeth was significantly higher, 2.15 ± 0.52. Compared to the samples obtained from the dental implants, the samples from natural teeth demonstrated significantly higher total bacterial cell numbers (P < .05). Consistent with the clinical measures of dental plaque, significantly higher numbers of oral bacteria, including aerobic and anaerobic bacteria, were found in dental plaque samples from teeth (aerobic 5.648 ± 0.512, anaerobic 6.243 ± 0.535, P < .0001) compared to implants (aerobic 5.430 ± 0.541, anaerobic 5.917 ± 0.523, P < .0001). In addition, there were significantly higher numbers of anaerobic (6.243 ± 0.535 and 5.917 ± 0.523, P < .0001) than aerobic (5.648 ± 0.512 and 5.430 ± 0.541, P < .008) bacteria for samples from teeth and implants, respectively. CONCLUSION: Clinical and microbiologic analyses provide consistent findings that suggest differences in quantity of plaque and bacterial species between teeth and dental implants. For long-term treatment success, the importance of plaque control and oral hygiene of both periodontal and dental implant therapy is emphasized.
Asunto(s)
Implantes Dentales/microbiología , Índice de Higiene Oral , Diente/microbiología , Adulto , Anciano , Bacterias Aerobias/clasificación , Bacterias Anaerobias/clasificación , Carga Bacteriana , Técnicas Bacteriológicas , ADN Bacteriano/análisis , Placa Dental/microbiología , Índice de Placa Dental , Femenino , Hemorragia Gingival/clasificación , Gingivitis/clasificación , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Humanos , Masculino , Microscopía de Contraste de Fase , Persona de Mediana Edad , Hibridación de Ácido Nucleico , Índice Periodontal , Adulto JovenRESUMEN
AIM: Supportive therapy to maintain dental implants is increasingly important. This study examined the effect of a 0.3% triclosan/2% copolymer dentifrice on oral biofilms and gingival inflammation (GI) on dental implants and peri-implant tissues. MATERIALS AND METHODS: One hundred and twenty adults with a dental implant and contra-lateral tooth were enrolled in this 6 month, double-blind, two-treatment, parallel group study. Sixty subjects were randomly assigned to a triclosan/copolymer dentifrice test group and 60 subjects to a fluoride dentifrice control group and instructed to brush twice daily for 6 months. At baseline, 3, and 6 months, a calibrated dentist assessed dental plaque, GI and collected supragingival dental plaque for microbiological analysis. RESULTS: Subjects in the triclosan/copolymer group demonstrated significantly lower levels of dental plaque, gingivitis, and bleeding on probing at 3 and 6 months at both the implant and contra-lateral tooth compared with the fluoride group (p<0.05). There were significantly fewer Gram-negative anaerobes in the triclosan/copolymer group (p<0.05) including >90% reductions in Aggregatibacter actinomycetemcomitans, Campylobacter rectus, Eubacterium saburreum, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella melaninogenica, Solobacterium moorei, and Tannerella forsythia. CONCLUSIONS: Twice daily use of a triclosan/copolymer dentifrice may enhance dental implant maintenance by reducing dental plaque and GI.
Asunto(s)
Biopelículas/efectos de los fármacos , Implantes Dentales/microbiología , Dentífricos/uso terapéutico , Gingivitis/prevención & control , Maleatos/uso terapéutico , Polivinilos/uso terapéutico , Triclosán/uso terapéutico , Adulto , Anciano , Análisis de Varianza , Bacterias/efectos de los fármacos , Recuento de Colonia Microbiana , ADN Bacteriano/análisis , Placa Dental/microbiología , Placa Dental/prevención & control , Dentífricos/farmacología , Método Doble Ciego , Combinación de Medicamentos , Femenino , Fluoruros/farmacología , Fluoruros/uso terapéutico , Humanos , Masculino , Maleatos/farmacología , Persona de Mediana Edad , Periimplantitis/prevención & control , Índice Periodontal , Polivinilos/farmacología , Infecciones Relacionadas con Prótesis/prevención & control , Triclosán/farmacología , Adulto JovenRESUMEN
This investigation compared the effects of a fluoride dentifrice and toothpastes formulated with antimicrobial ingredients (stannous fluoride and triclosan/copolymer) on oral micro-organisms, including those found in samples taken from the human oral cavity. Microbiological techniques determined the minimum inhibitory concentrations (MICs) of each dentifrice necessary to inhibit the growth of bacterial strains from the healthy oral cavity, as well as those found in dental caries, periodontal disease, and halitosis. Ex vivo studies utilized oral rinse samples and supragingival plaque from adults to determine antimicrobial effects on the entire microbial diversity of these samples, including biofilm-derived micro-organisms. The triclosan/copolymer dentifrice demonstrated the lowest MICs and significantly inhibited Gram-positive and Gram-negative bacteria (including the periodontal pathogens Aggregatibacter actinomycetemcomitans, Eikenella corrodens, and Fusobacterium nucleatum). In the ex vivo tests, the triclosan/copolymer dentifrice demonstrated substantial inhibition in the oral rinse samples over each treatment period (p > 0.0005) as compared to either the fluoride or stannous fluoride dentifrices. Similarly, the triclosan/copolymer dentifrice demonstrated the highest inhibition of micro-organisms in the supragingival plaque biofilm (p < 0.0005). No significant differences were observed between the fluoride and stannous fluoride dentifrices (p > 0.5).
Asunto(s)
Antiinfecciosos/farmacología , Cariostáticos/farmacología , Dentífricos/farmacología , Fluoruros/farmacología , Pastas de Dientes/farmacología , Actinomyces/efectos de los fármacos , Adolescente , Adulto , Anciano , Aggregatibacter actinomycetemcomitans/efectos de los fármacos , Antiinfecciosos Locales/farmacología , Campylobacter rectus/efectos de los fármacos , Capnocytophaga/efectos de los fármacos , Recuento de Colonia Microbiana , Placa Dental/microbiología , Eikenella corrodens/efectos de los fármacos , Fusobacterium nucleatum/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Ensayo de Materiales , Persona de Mediana Edad , Fluoruro de Sodio/farmacología , Factores de Tiempo , Fluoruros de Estaño/farmacología , Triclosán/farmacología , Adulto JovenRESUMEN
OBJECTIVE: In vitro testing of antimicrobial agents is an important tool in the testing hierarchy, and may provide interesting insights into their potential clinical efficacy. Agents with demonstrable in vitro antimicrobial activity may be effective against the same microorganisms in vivo, whereas agents without demonstrable in vitro antimicrobial activity are unlikely to exhibit in vivo antimicrobial activity. In addition, these methods may also be useful in screening antimicrobial agents in product formulations because such agents with both in vitro and in vivo activity may have reduced antimicrobial effects when formulated into a dentifrice. Accordingly, this study examined the in vitro and ex vivo antimicrobial activity of three commercial dentifrices: one formulated with 0.243% sodium fluoride (Crest Cavity Protection Toothpaste-Regular); one with 0.454% stannous fluoride, sodium hexametaphosphate, and zinc lactate (Crest Pro-Health), and one with 0.3% triclosan, 2.0% PVM/MA copolymer, and 0.243% sodium fluoride (Colgate Total). METHODS: The minimum inhibitory concentration (MIC) of each dentifrice was determined for resident oral bacterial species, including bacteria that are associated with dental caries; periodontitis, and oral halitosis. Evaluations were performed on individual laboratory strains, and on oral bacteria from supragingival plaque samples obtained from 10 adults and from oral rinse samples obtained from 18 adults. RESULTS: The lowest MICs against the oral strains and human samples, i.e., greatest antimicrobial activity, were seen for the triclosan/ copolymer dentifrice. There was, in general, a four-fold difference in MICs between the triclosan/copolymer dentifrice and the stannous fluoride/sodium hexametaphosphate/zinc lactate dentifrice. The triclosan/copolymer dentifrice significantly inhibited periodontal pathogens, such as Aggregatibacter actinomycetemcomitans, Eikenella corrodens, and Fusobacterium nucleatum. In ex vivo tests measuring antimicrobial effects, the triclosan/copolymer dentifrice substantially inhibited bacterial growth after 30-, 60-, and 120-second exposures compared to the sodium fluoride or stannous fluoride/sodium hexametaphosphate/zinc lactate dentifrices. Similarly, in ex vivo tests measuring antimicrobial effects on supragingival plaque biofilms, the triclosan/copolymer dentifrice substantially inhibited bacterial growth compared to the other test dentifrices. CONCLUSION: Different in vitro and ex vivo analyses show that the triclosan/copolymer dentifrice has significant antimicrobial activity on oral bacteria, including species causing dental caries, periodontitis, and oral halitosis, and it provides superior efficacy compared to the stannous fluoride/sodium hexametaphosphate/zinc lactate dentifrice.
Asunto(s)
Antiinfecciosos Locales/farmacología , Bacterias/efectos de los fármacos , Dentífricos/farmacología , Boca/microbiología , Adulto , Antiinfecciosos Locales/química , Cariostáticos/farmacología , Recuento de Colonia Microbiana , Dentífricos/química , Combinación de Medicamentos , Humanos , Maleatos , Pruebas de Sensibilidad Microbiana , Fosfatos/química , Fosfatos/farmacología , Polietilenos , Ácido Silícico/química , Ácido Silícico/farmacología , Fluoruro de Sodio , Fluoruros de Estaño/química , Fluoruros de Estaño/farmacología , Pastas de Dientes/química , Pastas de Dientes/farmacología , Triclosán , Compuestos de ZincRESUMEN
PURPOSE: This case-controlled study examined clinical and microbiological parameters in Brazilian children and adolescents receiving orthodontic treatment using fixed orthodontic appliances or removable orthodontic appliances. METHODS: The plaque index, gingival index, number of decayed, missing and filled teeth, and probing pocket depth was measured on each fully erupted tooth in 30 patients treated with fixed orthodontic appliances and an equal number of age and sex-matched control subjects. The same parameters were also measured in 18 patients treated with removable orthodontic appliances and an equal number of age and sex-matched control subjects. In the patients treated with fixed orthodontic appliances, subgingival plaque samples were collected from four teeth with orthodontic brackets and from four teeth with orthodontic bands. In the patients with removable appliances, subgingival plaque samples were collected from clasped maxillary permanent first molar teeth and from four unclasped permanent teeth. Samples of unstimulated whole saliva and samples from the dorsal surface of the tongue were also obtained from each subject. Each sample was analyzed for the presence of 19 target bacteria by dot blot. A subset of samples was examined by direct amplification of bacterial nucleic acids. RESULTS: Compared to their respective age and sex-matched controls, whole mouth means for plaque index and gingival index were significantly elevated in both the fixed and removable orthodontic groups. There was no difference in the DMFT. Subjects with fixed orthodontic appliances had a higher prevalence of each of the target species except for L. fermentum, Neisseriaceae and S. mutans. The prevalence of A. naeslundii and Streptococcus sp. was significantly higher on teeth with orthodontic brackets alone compared to teeth with both orthodontic bands and brackets. Subjects with removable orthodontic appliances had a higher prevalence of A. actinomycetemcomitans, C. rectus, E. corrodens, L. fermentum, Neisseriaceae, and spirochetes. The prevalence of Neisseriaceae was significantly higher on unclasped teeth compared to clasped teeth. There was no difference between sample sites for the target bacteria except for A. actinomycetemcomitans that was detected less frequently in saliva. Orthodontic patients demonstrated higher proportions of gram negative species by direct amplification of nucleic acids including species frequently associated with periodontal disease as well as rarely cultivable or non-cultivable species such as Abiotrophia defectiva, Gemella haemolysans, Granulicatella adiacens, Lautropia sp., Terrahaemophilus aromaticivorans, and TM7 bacterium.
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Placa Dental/microbiología , Aparatos Ortodóncicos/efectos adversos , Saliva/microbiología , Adolescente , Bacterias Anaerobias/genética , Proteínas Bacterianas/análisis , Estudios de Casos y Controles , Niño , Índice CPO , Placa Dental/etiología , Índice de Placa Dental , Femenino , Bacterias Gramnegativas/genética , Humanos , Masculino , Aparatos Ortodóncicos Removibles/efectos adversos , Soportes Ortodóncicos/efectos adversos , Alambres para Ortodoncia/efectos adversos , Índice PeriodontalRESUMEN
BACKGROUND: Dentists and other health care professionals are familiar with the impact of tobacco on oral and general health. However, oral health care professionals do not often provide tobacco-cessation counseling to their patients, thus reflecting a significant disconnect between research and clinical practice. This report demonstrates the benefits of tobacco cessation in resolving oral lesions and improving overall periodontal and oral health. METHODS: A 51-year-old white male presented to the University at Buffalo, School of Dental Medicine clinic requesting an oral and periodontal examination as part of a presurgical protocol prior to cardiac surgery. A review of the patient's history from a health questionnaire revealed that he was using smokeless tobacco every day. An oral examination revealed several white lesions (5 x 10 mm) on the maxillary right and left labial mucosa. The patient was provided with tobacco-cessation counseling as well as oral hygiene instructions and professional dental prophylaxis. RESULTS: An oral examination 2 weeks after tobacco cessation revealed complete resolution of the oral lesions and overall improvement of periodontal and oral health. CONCLUSION: Although the findings presented in this article are based only on a single case report, the improvement in the patient's oral health after cessation of tobacco use was dramatic and reinforces the belief that tobacco-cessation counseling should be a routine component of the standard of care for tobacco-using patients.
Asunto(s)
Enfermedades Periodontales/terapia , Cese del Hábito de Fumar , Profilaxis Dental , Estudios de Seguimiento , Recesión Gingival/etiología , Recesión Gingival/terapia , Humanos , Leucoplasia Bucal/etiología , Leucoplasia Bucal/terapia , Masculino , Persona de Mediana Edad , Higiene Bucal , Úlceras Bucales/etiología , Úlceras Bucales/terapia , Pérdida de la Inserción Periodontal/etiología , Pérdida de la Inserción Periodontal/terapia , Enfermedades Periodontales/etiología , Bolsa Periodontal/etiología , Bolsa Periodontal/terapia , Periodontitis/etiología , Periodontitis/terapia , Tabaco sin Humo/efectos adversosRESUMEN
BACKGROUND: The authors examined the tongue bacteria associated with oral halitosis (bad breath originating from the oral cavity), focusing on noncultivable bacteria-bacteria that cannot be identified by bacterial culture techniques. METHODS: The authors took samples from the dorsal tongue surface of eight adult subjects with halitosis and five control subjects who did not have halitosis. They identified the bacteria in these samples by using both anaerobic culture and direct amplification of 16S ribosomal DNA, a method that can identify both cultivable and noncultivable microorganisms. They analyzed the resulting microbiological data using chi(2) and correlation coefficient tests. RESULTS: Clinical measures of halitosis were correlated highly with each other and with tongue coating scores. Of 4,088 isolates and phylotypes identified from the 13 subjects, 32 species including 13 noncultivable species were found only in subjects with halitosis. Solobacterium moorei was present in all subjects with halitosis but not in any control subjects. CONCLUSIONS: Subjects with halitosis harbor some bacterial species on their dorsal tongue surfaces that are distinct from bacterial species found in control subjects. This finding is consistent with the hypothesis that halitosis has a microbial etiology. CLINICAL IMPLICATIONS: Like other oral diseases with microbial etiology, halitosis may be amenable to specific and nonspecific antimicrobial therapy targeted toward the bacteria associated with it.
Asunto(s)
Bacterias/clasificación , Halitosis/microbiología , Lengua/microbiología , Actinomyces/clasificación , Actinomyces/aislamiento & purificación , Adulto , Anciano , Bacterias/aislamiento & purificación , Bacterias Anaerobias/clasificación , Recuento de Colonia Microbiana , ADN Bacteriano/análisis , Femenino , Bacilos Grampositivos Asporogénicos/clasificación , Bacilos Grampositivos Asporogénicos/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Boca/microbiología , Poliaminas/análisis , Olfato , Streptococcus/clasificación , Streptococcus/aislamiento & purificación , Compuestos de Azufre/análisisRESUMEN
Actinobacillus actinomycetemcomitans is an oral pathogen that causes aggressive periodontitis as well as sometimes life-threatening, extra-oral infections. Iron regulation is thought to be important in the pathogenesis of A. actinomycetemcomitans infections and, consistent with this hypothesis, the fur gene has recently been identified and characterized in A. actinomycetemcomitans. In this study, 14 putatively Fur-regulated genes were identified by Fur titration assay (Furta) in A. actinomycetemcomitans, including afuA, dgt, eno, hemA, tbpA, recO and yfe - some of which are known to be Fur regulated in other species. A fur mutant A. actinomycetemcomitans strain was created by selecting for manganese resistance in order to study the Fur regulon. Comparisons between the fur gene sequences revealed that nucleotide 66 changed from C in the wild-type to T in the mutant strain, changing leucine to isoleucine. The fur mutant strain expressed a nonfunctional Fur protein as determined by Escherichia coli-based ferric uptake assays and Western blotting. It was also more sensitive to acid stress and expressed higher levels of minC than the wild-type strain. minC, which inhibits cell division in other bacterial species and whose regulation by iron has not been previously described, was found to be Fur regulated in A. actinomycetemcomitans by Furta, by gel shift assays, and by RT-qPCR assays for gene expression.
Asunto(s)
Aggregatibacter actinomycetemcomitans/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Proteínas Represoras/metabolismo , Aggregatibacter actinomycetemcomitans/genética , Aggregatibacter actinomycetemcomitans/crecimiento & desarrollo , Farmacorresistencia Bacteriana , Concentración de Iones de Hidrógeno , Hierro/metabolismo , Manganeso/farmacología , Mutación , Regulón , Proteínas Represoras/genéticaRESUMEN
STUDY OBJECTIVES: Poor dental hygiene has been linked to respiratory pathogen colonization in residents of long-term care facilities. We sought to investigate the association between dental plaque (DP) colonization and lower respiratory tract infection in hospitalized institutionalized elders using molecular genotyping. METHODS: We assessed the dental status of 49 critically ill residents of long-term care facilities requiring intensive care treatment. Plaque index scores and quantitative cultures of DPs were obtained on ICU admission. Protected BAL (PBAL) was performed on 14 patients who developed hospital-acquired pneumonia (HAP). Respiratory pathogens recovered from the PBAL fluid were compared genetically to those isolated from DPs by pulsed-field gel electrophoresis. MEASUREMENTS AND RESULTS: Twenty-eight subjects (57%) had colonization of their DPs with aerobic pathogens. Staphylococcus aureus (45%) accounted for the majority of the isolates, followed by enteric Gram-negative bacilli (42%) and Pseudomonas aeruginosa (13%). The etiology of HAP was documented in 10 patients. Of the 13 isolates recovered from PBAL fluid, nine respiratory pathogens matched genetically those recovered from the corresponding DPs of eight patients. CONCLUSIONS: These findings suggest that aerobic respiratory pathogens colonizing DPs may be an important reservoir for HAP in institutionalized elders. Future studies are needed to delineate whether daily oral hygiene in hospitalized elderly would reduce the risk of nosocomial pneumonia in this frail population.
Asunto(s)
Bacterias/aislamiento & purificación , Infección Hospitalaria/microbiología , Placa Dental/complicaciones , Placa Dental/microbiología , Neumonía Bacteriana/microbiología , Anciano , Anciano de 80 o más Años , Infección Hospitalaria/epidemiología , Placa Dental/epidemiología , Femenino , Humanos , Institucionalización , Masculino , Neumonía Bacteriana/epidemiología , Prevalencia , Estudios ProspectivosRESUMEN
Diabetics and smokers are two patient groups at high risk for periodontal disease who also exhibit impaired wound healing and, therefore, constitute two different groups in whom the relationship between host-parasite interaction, outcome of periodontal therapy, and systemic factors is best represented. The results of two independent clinical trials involving treatment of periodontal disease in diabetics and smokers are presented. A new treatment regimen-for the management of periodontal disease associated with diabetes mellitus is proposed. This treatment approach incorporates both antimicrobial agents and pharmacological modulation of the host response. Elimination of periodontal infection and reduction of periodontal inflammation in diabetic patients resulted in a significant short-term reduction in the concentration of glycosylated hemoglobin (HbA1c ). Control of chronic infections and modulation of the host response offer a new therapeutic approach in the management of patients with both diabetes and periodontal disease. The effect of smoking on periodontal healing is also discussed. The clinical and microbiological response of smokers to non-surgical periodontal therapy is compared to non-smokers. In addition, possible mechanisms whereby diabetes mellitus and cigarette smoking increase the severity of periodontal disease are discussed. J Periodontol 1996;67:1094-1102.
RESUMEN
Recent studies of the dental plaque bacteria associated with the various forms of early-onset periodontitis confirm the importance of target periodontal pathogens such as Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Prevotella intermedia, and Porphyromonas gingivalis in these diseases. A. actinomycetemcomitans strains exhibit a wide range of variability in leukotoxin production. By virtue of a unique promoter for the leukotoxin (ltx) operon, highly leukotoxic A. actinomycetemcomitans strains (e.g., JP2) express 10- to 20-times greater levels of leukotoxin than minimally toxic strains (e.g., 652). In dot blot hybridization and polymerase chain reaction (PCR) assays, the distribution of leukotoxic A. actinomycetemcomitans was examined among 165 fresh isolates and strains from our culture collection obtained from 91 human patients and non-human primates. Highly leukotoxic A. actinomycetemcomitans strains were found in 22% of the subjects and represented 28% of the isolates examined. This is a much higher prevalence than reported in a similar survey of A. actinomycetemcomitans strains from Northern Europe. Patients harboring the highly leukotoxic strains were much younger (mean age 12.7 years) than those harboring minimally toxic A. actinomycetemcomitans (mean age 25.5 years). In addition, patients with localized juvenile periodontitis were shown to have a substantially higher prevalence of highly leukotoxic strains than healthy individuals or those with adult periodontitis. Fifty-seven percent of the localized juvenile periodontitis patients harbored these strains and 64% of the isolates obtained from these patients were highly toxic A. actinomycetemcomitans. No highly toxic strains were identified from healthy individuals or from patients with adult periodontitis. The polymerase chain reaction assay could readily identify and distinguish the ltx promoters from highly toxic and minimally toxic A. actinomycetemcomitans in whole plaque samples. These data point to the importance of specific A. actinomycetemcomitans strains, as characterized by their expression of high levels of leukotoxin, in the pathogenesis of certain types of early-onset periodontitis and, possibly, other forms of rapidly progressing periodontitis. J Periodontol 1996;67:282-290.
RESUMEN
Serum antibody titers to Actinobacillus actinomycetemcomitans were measured in 200 subjects by an enzyme-lined immunosorbent assay (ELISA) using whole microorganisms as antigen. Comparisons were made between titers found in periodontally normal subjects and titers in subjects with localized juvenile periodontitis (LJP), postlocalized juvenile periodontitis, generalized juvenile periodontitis or adult periodontitis. It was found that titers to all three serotypes of A. actinomycetemcomitans were elevated in LJP patients' sera, while serum antibody levels in other diseased groups were not significantly elevated to any of the serotypes. Patient sera were also examined for serum antibody to oral Haemophili previously shown to cross-react with A. actinomycetemcomitans. Similar antibody titers were found in both normal subjects and in patients with various forms of periodontal disease to Haemophilus aphrophilus, H. influenzae and H. parainfluenzae. The A. actinomycetemcomitans antibodies which were elevated in LJP patients could not be correlated with antibody titers to cross-reacting Haemophili, suggesting that these antibodies are A. actinomycetemcomitansspecific. Serum antibody responses in six of the LJP patients were assessed to autologous strains of A. actinomycetemcomitans. Each patient was found to be infected with only a single serotype of A. actinomycetemcomitans, and specific antibodies to the infecting serotype were found in the patients' sera. In families, the LJP patients had significantly elevated IgG, IgA and IgM serum antibody titers to A actinomycetemcomitans, while the IgG and IgA antibody titers in periodontally normal siblings were at levels comparable to those found in normal subjects. However, IgM serum antibodies were elevated in the periodontally normal siblings of LJP patients suggesting that the formation of IgM antibodies to A. actinomycetemcomitans may precede the clinical appearance of localized juvenile periodontitis. Gingival crevicular fluid and serum antibody levels to A. actinomycetemcomitans were compared in LJP patients. Comparable titers of IgG, IgA and IgM antibodies were found in serum and gingival fluid in most subjects; however, gingival fluid samples sometimes showed higher titers than serum, likely resulting from local antibody synthesis. The value of serum antibody determinations to A. actinomycetemcomitans in the diagnosis of Actinobacillus-associated periodontitis was also assessed. The predictive value of a positive test (significantly elevated anti-A actinomycetemcomitans IgG) was 86%, while the specificity was 89%. These results suggest that the measurement of serum or gingival crevicular fluid antibodies to A. actinomycetemcomitans may be valuable in the diagnosis of Actinobacillusassociated periodontal disease.