Histological changes in the oral mucosa of the wistar rat treated with commercial lime (calcium hydroxide) - an optical and submicroscopic study

Abstract

The high incidence of oral cancer in different population groups in many south-east Asian nations has been stressed repeatedly in early and recent reports (Orr, 1933; Balendra, 1949; Cooray, 1944; Khanolkar, 1959; Muir, 1962; Pindborg, 1965). In India, and elsewhere, epidemiological and biological investigations have been done, or are in progress, on any possible correlation between the habitual use of the betel chew or " pan " and oral cancer. The involvement of the main constituents of " pan "-betel leaf (Piper betel), betel nut (Areca catechu), tobacco (Nicotiana tabacum), slaked shell or stone lime (slaked calcium hydroxide) and catechu (Acacia catechu) have also been considered individually or in combination (Mody and Ranadive, 1959; Muir and Kirk, 1960; Dunham, Muir and Hamner, 1966). The role of lime appears rather controversial, though some reports do suggest its correlation with the occurrence of oral cancer. It was therefore considered worthwhile to study the effects of slaked commercial lime on the oral mucosa of laboratory animals. The main aims of the study were to evaluate the part played by lime in the causation of oral malignancy or of oral conditions considered to be precancerous and the trauma it caused to epithelial and subepithelial tissue. This paper reports the histological changes produced on short term and prolonged application of lime to the oral mucosa of normal, diet conditioned and hormone treated Wistar rats.