Massive extrusion of calcium hydroxide paste containing barium sulphate during endodontic treatment.

A 31-year-old woman was referred for the evaluation of persistent lower lip numbness following endodontic treatment of tooth #36. Imaging examinations showed a large amount of radiopaque/hyperdense material spread in an angiographic distribution in the left mandibular body region. Laboratory analyses of tooth #36 and adjacent periapical tissue, surgically extracted in an external Service due to acute pain following endodontic treatment, identified chronic inflammatory reaction and birefringent crystalloid foreign bodies rich in barium and sulphur, leading to the diagnosis of alveolar nerve injury due to accidental extrusion of intracanal dressing material composed of calcium hydroxide [Ca(OH)2 ] paste incorporated with barium sulphate. Clinicians should be aware that Ca(OH)2 when in contact with periapical tissues may lead to persistent toxicities, such as necrosis, pain and paraesthesia. Therefore, injectable Ca(OH)2 systems should be used with caution because they can cause paste extrusion and damage to the lower alveolar nerve.

Head and neck radiotherapy does not increase gelatinase (metalloproteinase-2 and -9) expression or activity in teeth irradiated in vivo.

OBJECTIVE: Recent studies suggested that head and neck radiotherapy increases active forms of matrix metalloproteinases (MMPs) in the dentin-enamel junction (DEJ), leading to enamel delamination and radiation-related caries. This study aimed to assess the expression and activity of the gelatinases MMP-2 and MMP-9 in the DEJ and dentin-pulp complex tissues of teeth irradiated in vivo. STUDY DESIGN: Thirty-six teeth were studied, including 19 irradiated and 17 non-irradiated controls. In situ zymography was used to investigate the gelatinolytic activity in the micromorphologic components of enamel, DEJ, dentin-pulp complex, and caries. Immunohistochemical analysis was conducted on the demineralized samples to assess MMP-2 and MMP-9 expression levels in the DEJ, dentin-pulp complex components, and caries. RESULTS: No statistically significant differences were detected between groups in gelatinolytic activity or in MMP-2 expression levels (P > .05). Odontoblast MMP-9 expression was reduced in the irradiated group (P = .02). CONCLUSIONS: The study rejected the hypothesis that MMP-2 and MMP-9 would be overexpressed or more activated in the DEJ and dentin-pulp complex of irradiated teeth. Direct effects of radiation should not be regarded as an independent factor for explaining radiation-related caries onset and progression.