In vitro Caries-like Lesion Production by Streptococcus mutans and Actinomyces viscosus Using Sucrose and Starch

Abstract

We investigated the formation of caries-like lesions on root and enamel sections by S. mutans and A. viscosus when grown in four different carbohydrate substrates. The substrates were: sucrose, starch + alpha-amylase, and a combination of starch and sucrose with and without alpha-amylase. Twenty-four sections with exposed windows on both the root and enamel surfaces were exposed to the individual bacterial species in each of the four substrates for three weeks. At three weeks, the sections were removed and lesion depths measured. When grown in sucrose alone, S. mutans produced significantly deeper lesions in both root and enamel surfaces when compared with A. viscosus. However, S. mutans failed to produce lesions when grown in "limited" sucrose with starch added, whereas A. viscosus in this same substrate produced lesions in the enamel and root surfaces. A viscosus also produced either similar or significantly deeper lesions in both root and enamel surfaces, when compared with S. mutans grown in the two substrates with amylase. Thus, under these in vitro conditions, it was demonstrated that A. viscosus could utilize starch, whereas utilization of starch by S. mutans was alpha-amylase-dependent.

In vitro growth, acidogenicity and cariogenicity of predominant human root caries flora

“…Mean pH value of each group was calculated using the data derived from each of the 9 days of the experiment. 23,24 Observation of artificial plaque by scanning electron microscopy (SEM)…”

Structural and Molecular Basis of the Role of Starch and Sucrose in Streptococcus mutans Biofilm Development

“…Moreover, maltose and maltodextrins resulting from starch hydrolysis can be catabolized in acids by S. mutans (4). In this study, we investigated whether biochemical reactions involving interactions between specific host (␣-amylase) and bacterium-derived (Gtfs) enzymes and dietary carbohydrates (starch and sucrose) influence (i) the biochemical and structural properties of the EPS matrix and (ii) trigger specific adaptive responses by S. mutans at the transcriptional level, resulting in a biofilm with enhanced virulence.…”

Comparisons of in vitro Root Caries Models

“…Feagin and Graves [1988] used some of these systems with root surfaces as well. Clarkson et al [1984Clarkson et al [ , 1987 showed that uniform sub surface lesions could be produced in either enamel or root surfaces by using a bacterial system that generated the acid required for demineralization. Using polarized light mi croscopy (PLM), Phankosol et al [1985a] observed that similar uniform enamel and root lesions were formed in an acidified gel system.…”