Infection-stimulated infraosseus inflammation and bone destruction is increased in P-/E-selectin knockout mice.
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Infections of the dental pulp commonly result in infraosseus inflammation and bone destruction. However, the role of phagocytic leucocytes in the pathogenesis of pulpal infections has been uncertain. In this work we used P/E-/- selectin-deficient mice, which lack rolling adhesion of leucocytes to endothelium and mimic the human syndrome, leucocyte adhesion deficiency II (LAD-II), to test the hypothesis that phagocytic leucocytes protect against pulpal infection and subsequent periapical infraosseus bone resorption. P/E-/- mice and P/E+/+ wild-type controls were subjected to surgical pulp exposure, and both groups were infected with a mixture of pulpal pathogens including Prevotella intermedia, Fusobacterium nucleatum, Peptostreptococcus micros and Streptococcus intermedius. Animals were killed after 20 days, and the extent of infraosseus bone destruction was quantified by histomorphometry. In two separate experiments, P/E-/- mice had significantly greater bone resorption than P/E+/+ controls. The increased bone destruction correlated with a twofold decrease in polymorphonuclear (PMN) infiltration into periapical inflammatory tissues of P/E-/- mice. P/E-/- mice had higher tissue levels of the bone resorptive cytokine, interleukin (IL)-1alpha. Tissue levels of IL-2, IL-4, IL-10, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were all higher in P/E-/- mice, but the increases were not statistically significant. Only IL-12 was higher in P/E+/+ mice, possibly reflecting a greater number of infiltrating monocytes in wild-type mice. These findings demonstrate that phagocytic leucocytes are protective in this model, and suggest that elevated expression of inflammatory cytokines is responsible for the observed bone destruction. (+info)
Toll-like receptor 4-deficient mice have reduced bone destruction following mixed anaerobic infection.
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C3H/HeJ mice have an impaired ability to respond to lipopolysaccharide (LPS) due to a mutation in the gene that encodes Toll-like receptor 4 (TLR4). The effect of TLR4 deficiency on host responses to endodontic infections is unknown. In the present study, we compared periapical bone destruction, sepsis, and inflammatory cytokine production in LPS-hyporesponsive C3H/HeJ and wild-type control C3H/HeOuJ mice. The mandibular first molars of both strains were subjected to pulpal exposure and infection with a mixture of four anaerobic pathogens, Prevotella intermedia, Fusobacterium nucleatum, Streptococcus intermedius, and Peptostreptococcus micros. At sacrifice on day 21, TLR4-deficient C3H/HeJ mice had significantly reduced periapical bone destruction compared to wild-type C3H/HeOuJ mice (P < 0.001). The decreased bone destruction in C3H/HeJ correlated with reduced expression of the bone resorptive cytokines interleukin 1alpha (IL-1alpha) (P < 0.01) and IL-1beta (P < 0.05) as well as the proinflammatory cytokine IL-12 (P < 0.05). No significant differences were seen in the levels of gamma interferon, tumor necrosis factor alpha (TNF-alpha), or IL-10 between the two strains. The expression of IL-1alpha, IL-1beta, TNF-alpha, IL-10, and IL-12 were all significantly reduced in vitro in macrophages from both TLR4-deficient C3H/HeJ and C57BL/10ScNCr strains, compared to wild-type controls. Notably, the responses of TLR4-deficient macrophages to both gram-positive and gram-negative bacteria were similarly reduced. Neither C3H/HeJ nor C3H/HeOuJ mice exhibited orofacial abscess development or infection dissemination as determined by splenomegaly or cachexia. We conclude that intact TLR function mediates increased proinflammatory responses and bone destruction in response to mixed anaerobic infections. (+info)
The outcome of root canal treatment. A retrospective study within the armed forces (Royal Air Force).
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OBJECTIVE: The objective of this study was to investigate the outcome of conventional root canal treatment in a general practice setting within the Royal Air Force dental service. Design Retrospective review. METHODS: Teeth that had been root-filled for 12 months or more by Royal Air Force dental practitioners in patients attending a large Royal Air Force dental centre were included in the study. Following clinical and radiographic review the root fillings were classified as 'definitely successful', 'probably successful' or 'failed' The effect on success of several variables on the outcome was investigated. RESULTS: Out of a total of 406 teeth, 59% were maxillary teeth and 41% were mandibular teeth. Sixty-nine per cent of the total sample had pre-existing periapical radiolucencies. Cold lateral condensation of gutta-percha was the most widely used filling technique (64% of all cases). Fifty per cent of the teeth had root fillings within 2 mm of the radiographic apex, 32% were greater than 2 mm from the radiographic apex and 18% were overfilled. Cold lateral condensation was the most successful (92% overall) filling technique. Maxillary anterior teeth had a better success rate (96%) than other tooth types. Teeth with pre-existing periapical radiolucencies had a higher success rate (87%) than those cases where there was no pre-existing periapical radiolucency (80%). Root fillings that were less than 2 mm from the radiographic apex of the tooth had a higher success rate (88% overall) than those that were greater than 2 mm from the radiographic apex (77% overall). Of the 406 cases, 57% (n=231) were classified as definitely successful, 28% (n=114) were classified as probably successful and 15% (n=62) were classified as failures. Thus, the overall success rate combining definitely successful and probably successful root fillings was 85% (n=344). CONCLUSIONS: Root fillings placed using cold lateral condensation of gutta-percha to within 2 mm of the radiographic apex of the tooth were associated with the best outcome. (+info)
Periapical surgery of 29 teeth. A comparison of conventional technique, microsaw and ultrasound.
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OBJECTIVES: A clinical and radiological study is made of the results obtained with different periapical surgical techniques. MATERIAL AND METHODS: Twenty-nine single-root teeth from 29 patients with periapical pathology following correct endodontic treatment were divided into three groups: (A) 10 patients in which rotary instruments were used to perform osteotomy, apicoectomy and cavity preparation; (B) 10 patients in which rotary instruments were used to perform osteotomy and apical resection, with ultrasound root-end cavity preparation; and (C) 9 patients in which microsaws were used for osteotomy, and ultrasound for cavity preparation. All teeth were filled with IRM. Clinical and radiological controls were made after 10 days, one and 6 months, and one year. RESULTS: Clinical success with the absence of symptoms was achieved in 17 cases (58.6%), while in 16 patients (55.2%) the X-ray images showed complete bony regeneration (complete healing). The clinical success rate after one year was 40%, 70% and 66.7% in groups A, B and C, respectively, while complete radiographic healing was recorded in 30%, 60% and 77.8%. There were three failures in group A, two in group C, and none in group B. CONCLUSION: In conclusion, the best results were obtained when ultrasound was used for root-end cavity preparation. (+info)
Bone scintigraphy as an adjunct for the diagnosis of oral diseases.
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Bone scintigraphy is a very sensitive method for the detection of osteoblastic activity of the skeleton. The technique consists of imaging the uptake of bone-seeking radiopharmaceuticals, particularly technetium-99m labeled diphosphonates, in the mineral component of bone, which consists of hydroxyapatite crystals and calcium phosphate, as well as in the organic matrix such as collagen fibers. Plain radiographs, computed tomography, and magnetic resonance imaging are classified as structural imaging modalities, whereas bone scintigraphy is a functional method. In many cases, radionuclide imaging techniques are the only means by which early physiologic changes that are a direct result of biochemical alteration may be assessed, before significant bone mineral changes can be detected by other means. Since many oral diseases may cause metabolic changes in the oromaxillofacial complex, it would be of great value to use bone scintigraphy to evaluate more completely some conditions involving the bones in the region to formulate more appropriate treatment plans. Based upon the current literature, the authors discuss the possible applications of bone scintigraphy as a diagnostic and treatment planning adjunct for oral diseases. Bone scintigraphy has proven particularly useful in the study of malignant lesions and in the evaluation of vascularized bone grafts used for maxillofacial reconstructions. (+info)
Diabetes mellitus as a modulating factor of endodontic infections.
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Diabetes mellitus is a chronic disease with serious health consequences. The association between diabetes and periodontal disease is well documented. However, the progression and healing of endodontic infections in diabetic patients has not been adequately studied. In this review, diabetes mellitus is explored as a potential modulating factor of endodontic pathosis. Recent data on the relationship between the clinical presentation of pulpal and periradicular disease, as well as the outcome of endodontic treatment in diabetic and nondiabetic patients, are presented. Diabetics who present for endodontic treatment, particularly those with periradicular pathosis, may have increased perioperative symptoms. Cases with preoperative periradicular lesions are less likely to be determined successful two years or longer postoperatively if the patient reports a history of diabetes. Studies examining the pathogenesis of periradicular lesions in mouse models with uncontrolled type 1 diabetes suggest that the lesion size may be increased and the animals have increased serious sequelae. Preliminary findings suggest that some bacterial species may be more prevalent in necrotic pulp of diabetic than nondiabetic patients. More studies are needed to further explore the microbiology of endodontic infections and to determine effective treatment strategies in both diabetic and nondiabetic patients. (+info)
Histopathologic examination to confirm diagnosis of periapical lesions: a review.
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Most periapical lesions are represented by inflammatory cysts, granulomas, abscesses or fibrous scars. These inflammatory conditions are often termed "endodontic lesions" because pulpal necrosis is the initiating event in their pathogenesis. Although rare, other clinically confusing periapical lesions have been extensively documented in numerous case reports and short case series. These lesions represent a wide range of pathosis, including various developmental cysts, infections, benign but locally aggressive lesions, and malignancies. The literature describing these lesions and the value of a histopathologic examination in diagnosis is reviewed. (+info)
Prevalence of microorganisms in root canals of human deciduous teeth with necrotic pulp and chronic periapical lesions.
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The objective of this study was to evaluate bacterial prevalence in 31 root canals of human deciduous teeth with necrotic pulp and periapical lesions using bacterial culture. After crown access, the material was collected using absorbent paper points for microbiological evaluation and determination of colony forming units (CFU). Anaerobic microorganisms were found in 96.7% of the samples, black-pigmented bacilli in 35.5%, aerobic microorganisms in 93.5%, streptococci in 96.7%, and S. mutans in 48.4%. We concluded that in human deciduous teeth root canals with necrotic pulp and periapical lesions the infection is polymicrobial, with a large number of microorganisms and a predominance of streptococci and anaerobic microorganisms. (+info)