IADR Abstract Archives
Enamel Subsurface Lesion Developed by Dual-Species Biofilms
Objectives: This study aimed to develop a protocol for the formation of enamel subsurface lesions on bovine enamel by dual-species biofilms of Streptococcus mutans and Candida albicans in vitro, and to verify the influence of the presence of fluoride (F) and cariogenic challenges.
Methods: The biofilms were formed on bovine enamel blocks (8×8 mm) for 7 days, using artificial saliva (AS) as the growth medium. After 24 h of formation, the biofilms were grown in AS, supplemented or not with 0.005 ppm F or 0.008 ppm F. Every 24 h, the biofilms were exposed or not to a 20% sucrose solution, for 3 min (simulating a cariogenic challenge). On the 7th day, the biofilms were collected and the extracellular polysaccharides (EPS) content and the F, calcium (Ca), and phosphorus (Pi) concentrations in the biofilms were analyzed. The blocks were submitted to X-ray computed microtomography analysis to determine the mineral concentration (gHAp × cm-3 × µm). Data were submitted to 2-way ANOVA, followed by Fisher’s LSD or Student-Newman-Keuls’ tests (p<0.05).
Results: The exposure to the cariogenic challenge led to a significant increase in the biofilm carbohydrate concentrations in comparison to biofilms not exposed to the challenge, regardless of the presence of F in the AS. After the challenge, the biofilms grown in the presence of 0.008 ppm F presented significantly lower biofilm F levels in comparison to those not exposed to the challenge. The biofilms exposed to 0.008 ppm F and the sucrose challenge presented significantly lower depth of lesion and integrated area, and higher outer layer in comparison to biofilms grown on pure AS, exposed to the cariogenic challenge.
Conclusions: It is concluded that dual-species biofilms of S. mutans and C. albicans were capable to develop enamel subsurface lesions in vitro, influenced by the presence of F and exposure to a cariogenic challenge.
Methods: The biofilms were formed on bovine enamel blocks (8×8 mm) for 7 days, using artificial saliva (AS) as the growth medium. After 24 h of formation, the biofilms were grown in AS, supplemented or not with 0.005 ppm F or 0.008 ppm F. Every 24 h, the biofilms were exposed or not to a 20% sucrose solution, for 3 min (simulating a cariogenic challenge). On the 7th day, the biofilms were collected and the extracellular polysaccharides (EPS) content and the F, calcium (Ca), and phosphorus (Pi) concentrations in the biofilms were analyzed. The blocks were submitted to X-ray computed microtomography analysis to determine the mineral concentration (gHAp × cm-3 × µm). Data were submitted to 2-way ANOVA, followed by Fisher’s LSD or Student-Newman-Keuls’ tests (p<0.05).
Results: The exposure to the cariogenic challenge led to a significant increase in the biofilm carbohydrate concentrations in comparison to biofilms not exposed to the challenge, regardless of the presence of F in the AS. After the challenge, the biofilms grown in the presence of 0.008 ppm F presented significantly lower biofilm F levels in comparison to those not exposed to the challenge. The biofilms exposed to 0.008 ppm F and the sucrose challenge presented significantly lower depth of lesion and integrated area, and higher outer layer in comparison to biofilms grown on pure AS, exposed to the cariogenic challenge.
Conclusions: It is concluded that dual-species biofilms of S. mutans and C. albicans were capable to develop enamel subsurface lesions in vitro, influenced by the presence of F and exposure to a cariogenic challenge.