Artificial Caries-Like Lesions around Conventional, Fluoride-Containing and Dispersed Amalgams

Abstract

The study was undertaken to evaluate differences in development of caries-like lesions (wall lesions) around three principally different amalgams (conventional, fluoride-containing and dispersed) under standardized conditions. Amalgam restorations were made on sound buccal and lingual surfaces of extracted premolars. After 10 weeks in an acidified gelatin gel the teeth were sectioned through the restorations and planoparallel ground sections were produced. The enamel surrounding the restoration was studied by polarized light microscopy after imbibition with quinoline (n = 1.62). It was found that the depth of the wall lesion and the extent of demineralized enamel were significantly less around the fluoride-containing amalgam than around the other two. Although not always statistically significant, the largest extent of demineralization was seen in wall lesions surrounding the dispersed amalgam. The number, depth and extent of wall lesions were significantly smaller in the cervical part of the cavities than in the coronal part. Signs of intermediate remineralization processes (presence of dark zones) were most often seen in relation to the fluoride-containing amalgam. These findings are discussed in relation to other differences between the amalgams, such as sealing property and corrosion proneness.

Effect of fluoride amalgams on artificial recurrent enamel and root caries

“…As no difference in lesion depth could be seen between the four experimental groups at the midpoint of the artificial lesions, suffieient fluoride does not seem to be distributed to these areas. This is in accordance with results from previous studies (15,16). Clinically, recurrent caries is considered to start at the fining margin, spreading along the wall as wefl as along the tooth surface.…”

“…However, no inhibitory effect was observed in other parts ofthe lesion. Two previous studies have reported inhibitory effects on in vitro wall lesions adjacent to fluoride-containing fillings inserted in enamel (15,16). No effect on outer enamel lesions was observed.…”

“…Reduced enamel solubility adjacent to has been added to the alloy as powdered fluoride-containing amalgam fillings has stannous fluoride. Release of fluoride from been reported (14), and inhibition of enamel cavity wall lesions around conventional fluoride-amalgam flllings (containing 1 % SnF,) has been shown in vitro (15,16). The aim ofthe present investigation was to evaluate the inhibitory effect of conventional and non-gamma-2 amalgams on the development of recurrent enamel and root surface lesions in vitro.…”

Experimental Secondary Caries around Restorations in Roots

“…It was, however, interesting to examine whether this effect also could be demonstrated in root surfaces. It has been suggested earlier [Custer and Coyle, 1970;Jerman, 1970;Heintze and Mornstad, 1980] that amal gam with an additional amount of sodium or stannous fluoride could have clinical advantages. The material was included in the experiments even though lack of long time studies and sparsely reported experi ences may confine its importance.…”

Experimental microleakage around ageing dental amalgam restorations: a review

“…The fluoridated dental amalgams have been seen to reduce the associated enamel solubility (Jerman, 1970;Heintze & Mornstad, 1979). The tests which are needed before the widespread use of fluoridated amalgams can be considered should include longitudinal experimental microleakage tests.…”