Experimental toxicity of monomers used to synthesis of hydrogels for medical applications

Abstract

Background. Although the spontaneous exfoliation of teeth and breakdown of oral tissues from severe mercury intoxication have been noted for over a century, there are no published reports investigating the mechanisms of these phenomena. Severe mercury poisoning is rare in modern times, but it does occur. We present a case report and a histopathologic investigation into the mechanism of the associated tooth loss.Methods. An exfoliated tooth and periodontal and gingival tissues were obtained from a 15-month-old patient who had been severely intoxicated with elemental mercury over a period of months and hospitalized for severe neurologic and renal effects. The tissues were examined both by routine hematoxylin and eosin stain and by autometallography specific for mercury. For comparison, control tissue from an age-matched subject was examined with the autometallography technique.Results. Under light microscopy, the gingival tissue showed evidence of moderate to severe acute and chronic inflammation. The tooth pulp tissue showed evidence of moderate vascular dilatation and congestion, and it was infiltrated by many neutrophils. The autometallographic sections showed intense accumulations of mercury in the soft tissues of the mercury-exposed subject, but not in the tissues of the control subject. The deposits were primarily found in fibroblasts, which are essential to maintaining the integrity of the oral tissues.Conclusions. Histopathologic and autometallographic examination of the affected tissue indicates that the primary mechanism of the spontaneous sloughing of tissue and loss of teeth may be the cytotoxic effects of the accumulation of mercury in fibroblasts. Studies of additional cases would be valuable to confirm this hypothesis.