The damaging effects of restorative materials. Part 2.--Pulpal effects related to physical and chemical properties

Bacterial microleakage and pulpal inflammation in experimental cavities

“…Sections were stained by haematoxylin and eosin or by Twort's modification of Gram's method. A complete description of the histological changes has been reported elsewhere (Plant & Jones 1976, Tobias 1980, Tobias et al 1978. In addition, the extent of the pulpal inflammation in the odontoblast layer and elsewhere in the pulp was scored on a 0-4 scale according t o the criteria indicated in Table I1 and described in detail elsewhere (Browne et nl.…”

“…In ferrets, the cavities were prepared cervically on the labial aspect of the canines and in humans, occlusally in premolar teeth destined for extraction as part of orthodontic treatment. The technique of cavity preparation has been fully described elsewhere (Plant & Jones 1976, Tobias et al 1978.…”

Pulpal effects of glass ionomer cements

“…Under local anaesthesia, occlusal cavities were prepared in caries-free premolar teeth which were destined for extraction as part of orthodontic treatment. The method of cavity preparation was the same as that used in previous studies (Plant & Jones 1976, T<Mx& et al, 1978, Water-cooled tungsten carbide burs, round (ISO size 016) and flat fissure (ISO size 012) running at speeds not exceeding 30,000 rpm were used. Each cavity was washed and dried with cotton wool bef<ve the material was inserted.…”

Fluoride as the possible cytotoxic component of Silicap. 1. Fluoride release

“…Dentine gives some protection t o the pulp from the toxic constituents of restorative materials (Browne & Tyas 1979). It is generally considered that the greater the thickness of the residual dentine, the greater the protection of the pulp (Darvell 1981, Avery 1975, although this was not confirmed by Plant & Anderson (1978). Little attention has been given t o simulating the protective role of residual dentine in tests for assessing the toxicity of dental restorative materials in vitro.…”

“…Most studies in vivo indicate that unlined silicate cements cause severe pulpal inflammation (Beagrie 1979, Brannstrom et al 1979, although more recent studies have reported only a mild response (Plant & Jones 1976). It has recently been shown that the pulpal response varies with the type of silicate cement and that such variation is associated with the different degree of microbial microleakage at the material/ cavity wall interface (Tobias et al 1981) rather than with differences in the release of toxic components from the silicate cements.…”