Immunoelectron microscopic study of Actinomyces colony in odontogenic periapical infection

Scanning Electron Microscopy of the Apical Structure of Human Teeth

The objective of this research was to evaluate, by scanning electron microscopy, the apical structure of extracted human permanent teeth with different degrees of pulp and periapical pathology. A total of 25 teeth were extracted: 5 teeth with vital pulp (group I); 10 teeth with pulp necrosis without radiographically visible periapical lesion (group II); 10 teeth with pulp necrosis with radiographically visible periapical lesion (group III). The root apex was sectioned and processed for scanning electron microscopy. In groups I and II, fibers covered the root cementum and there was no cementum resorption or microorganisms. There were areas of cementum resorption in group III with microorganisms on the root apex surface (biofilm) and no fibers. The authors conclude that the presence of chronic periapical lesions causes severe changes in the apical structure with a destruction of fibers and different degrees of cementum resorption forming lacunae in which bacterial biofilm persisted.

Case report of regional alveolar bone actinomycosis: a juvenile periodontitis-like lesion

BACKGROUND

Cervicofacial actinomycosis infection most often involves the mandibular bone and rarely the alveolar crest.

METHODS

We describe a 14-year-old patient who had actinomycosis involving the alveolar bone at the left lower dental quadrant region. Resembling juvenile periodontitis, it was difficult to diagnose properly and resulted in devastating dental and periodontal consequences: loss of one tooth with most of its adjacent regional alveolar bone, severely compromising the support of two other teeth.

RESULTS

With the diagnosis came successful treatment, including surgical removal of the soft and hard tissues with concomitant prolonged penicillin administration.

CONCLUSIONS

We feel that this case should raise the interest and concern of both the periodontist and the general practitioner so that early diagnosis can be obtained, significantly improving the clinical outcome.

Cervicofacial actinomycosis: a diagnostic challenge

Actinomycosis was first described as a clinical entity over 100 years ago. However, the fundamental characteristics of this entity have not been fully discussed, and major questions remain unanswered, such as the highly diversified pathogenicity of the phenomenon according to numerous published case reports and clarification of solid diagnostic criteria. Even the frequency of cervicofacial actinomycosis occurrence is unclear; some authors consider it to be rare and others to be common. We present 11 cases examined and treated in our department within the last 14 years along with a review of the literature. Diagnostic problems are emphasized, and a comprehensive overview of the entity is suggested.

Susceptibility of Actinomyces israelii to antibiotics, sodium hypochlorite and calcium hydroxide

Actinomyces israelii has been repeatedly implicated as a cause of failure of endodontic therapy. This study investigated the antimicrobial effect of antibiotics as well as intracanal medicaments, sodium hypochlorite solution and calcium hydroxide, on this important pathogen. Growth of A. israelii was inhibited by low concentrations of antibiotics, yet high concentrations were not bactericidal for A. israelii over 1 week. When A. israelii was exposed for 2-6 weeks at concentrations equivalent to clinical serum levels, the antibiotics were lethal. The results reveal a species-specific antibiotic tolerance for A. israelii. Both sodium hypochlorite solution and calcium hydroxide were found to be highly effective in killing A. israelii.

Periapical actinomycosis: report of a case and review of the literature

This case of periapical actinomycosis presented the clinical picture of chronic periapical inflammation. The diagnosis was based on the histological examination of the periapical lesions suggesting the necessity for routine histological examination. Although root canals provide a primary port of entry the Actinomyces organisms into the periapical tissue, periapical actinomycosis, is considered extremely rare. This may be due to the omission of routine histological examination of periapical lesions and the clinical behavior of the disease. The large number of cases reported during the last decade indicates that periapical actinomycosis is more frequent than what it is believed and this is important in the daily dental practice.

Comparison of polyclonal and monoclonal antibodies to Actinomyces and Arachnia species

Polyclonal (PoAbs) and monoclonal (MoAbs) antibodies were produced to Actinomyces israelii serotypes 1 and 2, to Actinomyces naeslundii, and to Arachnia propionica, and their specificities were studied by an enzyme immunoassay (EIA). All PoAbs except those to A. propionica reacted also with at least one other Actinomyces species. Only the MoAb to A. naeslundii proved to be more specific than the corresponding PoAbs. This MoAb did not crossreact with other Actinomyces or Arachnia species, nor with any other anaerobic or aerobic bacteria studied by inhibition EIA. Immunoblotting studies indicated that the antibody specific to A. naeslundii is directed against a large molecular weight antigen (greater than 150 kd), probably polysaccharide in nature. The produced PoAbs and MoAbs can be used for further analyses of the antigenic determinants of different Actinomyces and Arachnia species.