Mediators of acute and chronic periradicular lesions

Multiple mechanisms are involved in the pathologic changes associated with formation of acute and chronic periradicular lesions. Mechanical injury to the periradicular tissues can cause activation of several pathways of inflammation and release of nonspecific mediators. Continuous irritation of periradicular tissues can cause activation of several pathways of inflammation and release of nonspecific mediators. Continuous egress of antigens from a pathologically involved root canal can also result in one or a combination of the various types of immunologic reactions. A number of these reactions participate in the destruction of periradicular tissues. Because of complex interactions between the various components of these systems, the dominance of any one pathway or substance may be difficult to establish.

Interleukin-1 alpha and interleukin-1 beta periapical exudates of infected root canals: correlations with the clinical findings of the involved teeth

This study quantified the concentrations of interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) in the periapical exudates obtained from 69 single-rooted teeth using enzyme-linked immunosorbent assays, and examined their correlation with clinical findings of the involved teeth. Changes in the levels of these factors during root canal treatment were also investigated. The average levels of IL-1 beta (6.57 ng/ml) in periapical exudates were twice that of IL-1 alpha (3.25 ng/ml). The exudates containing pus showed significantly higher IL-1 alpha levels than those from the canals without pus (p < 0.01). The exudates from the canals with small radiolucent areas contained significantly higher IL-1 alpha levels than those from the canals with large radiolucent areas (p < 0.05). The tendency for there to be an increase in the levels of IL-1 alpha and a decrease in the levels of IL-1 beta was observed following root canal treatment. These observations suggest that IL-1 alpha and IL-1 beta are involved in the immunopathogenesis of periapical lesions and that IL-1 alpha and IL-1 beta may play different roles in the healing process of periapical lesions during root canal treatment.

Polymerase chain reaction detection of human immunodeficiency virus DNA in human periradicular lesions

Human immunodeficiency virus (HIV) has been previously reported to be present in the dental pulp of a patient with AIDS. The present report investigated the feasibility of polymerase chain reaction (PCR) amplification to detect the HIV proviral DNA in cells from periradicular lesions from an HIV-positive patient. The standard PCR amplification with 30 cycles and the nested PCR consisting of two 25-cycle amplifications were used. Samples from each reaction were separated by nondenaturing polyacrylamide gel electrophoresis and stained with ethidium bromide for visualization. Gels were electroblotted to nylon membranes, which were then fixed, denatured, and dried. Membranes were hybridized to specific radioactive oligonucleotide probes and placed next to Kodak XAR film for visualization of the HIV-specific bands. No evidence of HIV-specific reaction was observed in cells (negative control) or in two periradicular lesions from two HIV-negative patients. The ethidium bromide strains revealed that PCR amplification of DNA extracts from two lesions from the HIV-positive patient yielded PCR bands (with both primer pairs) which corresponded to HIV-specific bands of the expected size.

The granulomatous response and oral cavity

The granulomatous response is a phylogenetically primitive specialized immunological reaction of the body to wall off an irritant, ingest and remove it, characterised by a localized collection of epithelioid cells, macrophages and lymphocytes. The cells forming the granuloma, its mechanism of formation and types of granuloma have been discussed. A classification of granulomatous diseases of the oral cavity based on etiology has been suggested.

The role of reactive oxygen intermediates in the pathogenesis of chronic apical periodontitis

The level of malondialdehyde, a stable end product of lipid peroxidation induced by reactive oxygen intermediates and the activity of two potent antioxidant enzymes, superoxide dismutase and glutathione peroxidase, was investigated in tissue homogenates of 22 surgical periapical granuloma specimens. Malondialdehyde levels were significantly higher and glutathione peroxidase activity was significantly lower in periapical granuloma samples than in healthy gingival tissue homogenates, which were used as controls. The activity of superoxide dismutase was similar in periapical granuloma and in control samples. Our results indicate an altered balance between the production and the elimination of toxic oxygen metabolites in chronic apical periodontitis. We hypothesize that reactive oxygen intermediates, which are being produced by activated phagocytic cells abundantly present in periapical granulomas, can contribute to periapical tissue injury and bone loss in this disease.

Long-term retention of a paper point in the periapical tissues: a case report

A case is reported of a 15 mm paper point found in the periapical area of a maxillary right central incisor during endodontic surgery for an unresolved periapical radiolucency. The paper point had been present for between five and nine years. Histopathological examination showed the presence of chronically inflamed fibrous connective tissue with a number of foreign body giant cells and focal collections of chronic inflammatory cells. SEM comparison of the specimen with a similarly treated fresh paper point showed no indication of degradation of the paper point by host defense cells.

Incidence of periradicular pathoses in endodontic treatment failures

Biopsy reports from 150 periradicular tissue specimens obtained from teeth refractory to nonsurgical endodontic therapy were reviewed. The specimens were submitted by postdoctoral dental students in the Department of Endodontics, and the biopsy reports were prepared by oral pathologists at the University of Texas Health Science Center at San Antonio. The study found that 59.3% of the periradicular lesions were granulomas, 22% cysts, 12% scars, and 6.7% other pathoses. The majority (56%) of endodontically treated cases which failed to heal were recognized within 2 yr after the completion of therapy. The most common location for surgical retreatment was the anterior maxilla, followed by the posterior maxilla, the posterior mandible, and the anterior mandible. The periapical granuloma was the predominant pathosis at each location.

Langerhans' cell histiocytosis in association with periapical granulomas and cysts

This report describes a series of six cases of inflammatory periapical disease with small aggregates of Langerhans cells as a minor component. Immunohistochemical findings confirm that the cells are phenotypically related to Langerhans cells. Aggregates of these cells are not normally found in radicular cysts or periapical granulomas and have been interpreted to represent chronic localized Langerhans' cells histiocytosis. Whether these lesions, which arise within the context of chronic inflammatory periapical disease, represent incipient eosinophilic granulomas or are a more benign, minimally destructive form of Langerhans' cell histiocytosis is unknown. Clinical follow-up suggests that these lesions remain localized and that curettage is adequate treatment.

Identification of common foreign material in postendodontic granulomas and cysts

The present investigation was undertaken to identify commonly occurring foreign material in postendodontic periapical granulomas and cysts. 29 biopsies from such lesions with observed foreign material were routinely processed, stained with H&E, von Kossa and Calcofluor White and investigated by light, polarization and fluorescence microscopy. Applying back-scattered SEM images, the foreign material was subjected to energy dispersive X-ray analysis. 4 groups of foreign material were observed: 1. Black/brownish fragments and yellow/brown granules containing Au, Ag, Cu, Hg, Sn and Zn compatible with amalgam. 2. Fine black/brown/yellow granules compatible with endodontic sealer components revealing Ag, Ba, Bi, Cu, S, Ti and Zn. 3. Basophilic fragments compatible with Ca salts from Ca(OH), extruded periapically and containing Ca and P. 4. Elongated/rounded/oval/kidney-shaped, colourless to slightly basophilic, birefringent structures revealing C and O and with a slit-like central canal and a bright, pale-blue fluorescence specific for cellulose.

Kinetics of bone-resorbing activity in developing periapical lesions

The presence and kinetics of bone-resorbing activity in periapical lesions were studied with a rat model system. Lesions were found to expand most rapidly between induction on day 0 and day 15 ("active phase"), with enlargement occurring at a slower rate thereafter (days 20 and 30, "chronic phase"), as assessed by measurement of magnified radiographs and automated image analysis. Pooled extracts of periapical tissues obtained on day 15 contained significant levels of bone-resorbing activity, as determined by 45Ca release from pre-labeled fetal rat long bones. Normal rat dental pulp and periodontal ligament contained no activity. In two kinetic experiments, highest levels of bone-resorbing activity were detected in tissues on days 10 (10.4% and 11.6% specific 45Ca release/mg/mL) and 15 (8.9%). Activity declined thereafter on day 20 (4.4% and 6.1%) to near baseline levels by day 30 (1.4% and 3.3%). Identical levels of resorbing activity were found in the presence or absence of polymyxin-B, an inhibitor of bacterial lipopolysaccharide. These findings demonstrate that bone-resorbing activity is temporarily related to periapical bone destruction and suggest that this model may be useful for studies of mediators that are involved in the pathogenesis of inflammatory bone resorption.

[Inflammatory odontogenic lesions of the jaws]

The apical granuloma, the periapical abcess and the radicular cyst are the most frequent between the inflammatory odontogenic lesions of the jaws. These three lesions are caused by the necrosis of the pulp but are very different between each other from an histological point of view and they can correspond to different stages of the same pathological process considering the fact that from a granuloma can arise a periapical abcess or a radicular cyst and from a radicular cyst and abcess can originate. About these three pathological processes we discuss in this article the clinical, radiographical, ethiological, microscopical features, we suggest the treatment and the differential diagnosis.

[The role of acute phase proteins in the pathogenesis of chronic periapical granuloma]

Alpha-1-antitrypsin, alpha-2-macroglobulin, C-reactive protein, haptoglobin and complement component C 3 concentrations and oxidase activity of ceruloplasmin were studied in sera of 36 patients with chronic periapical granuloma before and after surgical treatment. Mean serum concentrations of the investigated proteins were slightly elevated at diagnosis, with the exception of haptoglobin. Alpha-1-antitrypsin and ceruloplasmin levels decreased significantly 7 days after apicectomy, the four other proteins were unchanged at this sampling time. Each investigated protein decreased significantly 3 months after apicectomy. This is the first longitudinal study of "acute-phase proteins" in chronic periapical granuloma. The results suggest that inflammatory reactions contribute to the maintenance of chronic periapical lesion.

[The causes of post-endodontic failure: a descriptive analysis of a population of 198 cases of surgical retreatment]

In this article, a statistical analysis describes 198 cases of post-endodontic failures referred from private practitioners for surgical retreatments. Biopsies of these lesions showed that 68.18 per cent of them were identified as apical granulomas, 3.5 per cent as cysts, 16.16 per cent as epitheliated granulomas and 12.12 per cent as "other" cases. The two main groups of causes associated with these failures are: technical errors (55.05 per cent of the cases) and procedural mistakes (17.68 per cent).

[After pulpectomy--dento-periodontal adaptation]

Recovery after an endodontic treatment can only be assessed clinically, on the basis of symptomatological and radiographic data, for lack of histo-clinical correlations. An anatomicopathological examination of damaged tissues pinpoints the anatomical obstacles and tissular modifications apt to undermine the success of root canal work. The aim of endodontic treatment is to maintain or reinstate an environment conducive to healing through the use of a non-traumatic endodontic technique, followed by functional rehabilitation of the dental organ in its periodontia structures.

Unusual periodontal findings in an AIDS patient with Burkitt's lymphoma. A case report

This report deals with a case of AIDS-related Burkitt's lymphoma in which some of the earliest findings were dental and periodontal in nature. The patient presented initially with painless and extremely loose teeth accompanied by progressive paresthesia of the lower jaw. Unique radiographic findings included extensive periodontal ligament space widening and bulbous, granuloma-like lesions about the apices of the teeth. These findings were associated with progressive tumor infiltration of the mandible and do not appear to be related to other reports of aggressive periodontitis associated with impaired immunologic functions in AIDS patients.

[Granuloma or cyst? The unknown chronic periapical lesion]

The periapical lesions, granuloma and cyst, are being dealt with in modern scientific articles. The ethiology, whether it be infectious, traumatic, physical or chemical, is reviewed and mention is made of the fact that pulpal necrosis or gangrene is a prerequisite for these chronic proliferous lesions. According to epidemiological studies, the granuloma is observed more often than the cyst and the cyst more often in the upper jaw bone. Furthermore, certain teeth show a particular susceptibility to one or the other of these lesions. An x-ray is not sufficient to assure the appropriate clinical diagnosis. Electrophoresis and histopathology does, however, allow one to do the same. Acting as an immunological entity, the granuloma is less of an immunological irritation than a local defense protective barrier.

Cellulose fibers from endodontic paper points as an etiological factor in postendodontic periapical granulomas and cysts

Histological sections of eight periapical granulomas and cysts developing after conventional endodontic therapy and displaying faintly hematoxylinophilic, birefringent foreign bodies were investigated by light and polarization microscopy, scanning electron microscopy, energy-dispersive X-ray, and chemical analysis. In addition to a variably dense mononuclear infiltrate, the granulomas and cysts revealed varying amounts of giant cells associated with the birefringent foreign bodies. These structures were identified as cellulose fibers, most probably originating from endodontic paper points, which in our opinion can be held responsible for the initiation and perpetuation of chronic postendodontic periapical lesions.

[Immunopathologic mechanisms associated with granulomas and odontogenic cysts: a general review]

The authors make a general survey of the immunopathological mechanisms involved in odontogenic cysts and granulomas. The dental pulp and the sound periapical tissues contain neither inflammatory nor immunoglobin-producing cells. Dental decay associated with bacterial aggression of the dental pulp and periapical tissues might induce a nonspecific inflammation which subsequently becomes more specific. Immunoglobulins are present in fluid aspirates from odontogenic cysts and granulomas. Several investigations have pointed out nonspecific inflammatory mediators (including the C3 complement components), T lymphocytes (helpers and suppressors), B lymphocytes, protein S-100 + cells (Langerhans cells). The presence of immunoglobulins, immunocompetent cells and C3 complement components confirms that all constituents of both humoral and cell-mediated immunological reactions might play an essential role in the pathogenesis of osteolysis.