The effect of non-restorative treatments on the progression of artificial dentine caries lesions underneath enamel

Abstract

Objective: To develop an experimental model for hidden caries lesions and to evaluate the effect of 0.12% chlorhexidine (CHX) and 1.23% acidulated phosphate fluoride (APF) on biofilm formation and on the dentine demineralization. Methods: Dentine discs with artificial lesions were divided into four subgroups (500-100-0 μm gaps or sound enamel). Enamel discs were adapted over the dentine samples and fixed in acetate matrices. Microcosm biofilms were formed on the specimens for 10 days (cariogenic condition). Specimens from subgroups (n=9) were individually treated for 1 min by daily immersion in CHX or saline, or weekly in APF suspension. Biofilms were quantified [total microorganism (TM) and mutans streptococci (MS)]. Mineral profiles were assessed by Transverse Microradiography. Data were analyzed by ANOVA, Holm-sidak and paired t-test (p<0.05). Results: CHX decreased MT counts and increased MS counts compared to other treatments in gaps presence or absence (p<0.05). For the control, 500 μm gap caused higher TM counts (p=0.024). No significant differences (treatment groups × subgroups) were found for the mineral profiles. Conclusion: 500 μm gap does not generate higher microbial colonization and CHX does not inhibit MS colonization of surfaces. APF and CHX showed positive trend for lesions remineralization. Copyright: