Caries lesion development and biofilm composition responses to varying demineralization times and sucrose exposures

Abstract

Link to this article: http://journals.cambridge.org/abstract_S1479050504001474How to cite this article: M. Fontana, A. Haider and C. González-Cabezas (2004). Caries lesion development and biolm composition responses to varying demineralization times and sucrose exposures. A B S T R A C TThe aim of this research was to study the effect of varying incubation times and sucrose exposures on lesion development and biofilm composition using a multi-species biofilm caries model. Two studies were conducted. In study 1, enamel specimens were divided into four groups, inoculated with a mixed overnight culture of Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, Streptococcus parasanguis and Streptococcus salivarius, and exposed to circulating trypticase soy broth + 5% (w/v) sucrose (TSBS; 30 min, three times per day (3×/day)) and a mineral washing solution containing 0.25 p.p.m. fluoride (22.5 h/day) for 2, 5, 6 or 8 days. In study 2, additional enamel specimens were divided into four groups and exposed to the same biofilm for 7 days, but with variations in the feeding schedule: TSBS 3×/day for 5 min, TSBS 3×/day for 15 min, TSBS 3×/day for 30 min, or TSBS 3×/day for 30 min + 1×/day for 15 min. At the end of each study, bacterial colonization counts and lesion size were determined. In study 1, specimens developed significantly deeper carious lesions with longer demineralization time (average lesion depth was 52.16 µm, 67.86 µm, 84.91 µm, and 99.97 µm, respectively, for 2, 5, 6, and 8 days). In study 2, there was no significant difference in size between the lesions developed at feeding schedules of 3×/day for 5 or 15 min. Lesions exposed to longer (30 min) and more frequent feeding schedules (4×/day) were significantly larger than the other groups. In both studies, all five bacterial species were able to colonize the enamel and were present in all groups at the end of the experiments, with predominance of lactobacilli over S. mutans. In conclusion, larger lesions were observed with increased incubation time and more frequent feeding schedules, with small variations in biofilm composition.

Enamel Carious Lesion Development in Response to Sucrose and Fluoride Concentrations and to Time of Biofilm Formation: An Artificial-Mouth Study

“…Enamel carious lesions were produced using a multispecies microbial model for caries formation developed by Fontana et al [20, 23] with modifications.…”

“…For biofilm formation, the following species were used: Actinomyces naeslundii (ATCC 19039), Lactobacillus casei (ATCC 4646), Streptococcus mutans (UA 159), Streptococcus salivarius (ATCC 25975), and Streptococcus sanguinis (BAA-1455) [20]. The strains were cultivated on Columbia Blood Agar (CBA; Difco, Sparks, MD, USA).…”

“…All slabs were coated with 20 μ L of filter-sterilized pooled saliva for 20 min. The preparation of saliva was described elsewhere [20]. Saliva was obtained from healthy donors.…”

“…On the other hand, multispecies biofilms models based on the cultivation of specific microorganisms might create a more controlled and less variable condition for carious lesions development. Therefore, an in vitro artificial-mouth multi-species microbial model was developed to create incipient carious lesions on enamel specimens induced by commensals and known cariogenic bacteria [20]. That model presents the advantage of simulating the feast and famine episodes present in the oral cavity since the carbohydrates are provided to the biofilm only for short periods of time mimicking the three main meals a subject may have per day in a clinical condition.…”

Incipient caries lesions on cementum by mono- and co-culture oral bacteria

“…11 Fivespecies bacteria co-culture system has also been used to produce enamel lesions. 12 Even in these simplified systems, the effect of individual bacteria on each other has not been studied. An in vitro study using root cementum and different combinations of cariogenic microorganisms produced varying depths of demineralization 13 ; further study found a correlation between the combination of cariogenic microorganisms and the depth of lesion on the root surface.…”