title: The effects of lesion baseline characteristics and different Sr:Ca ratios in plaque fluid-like solutions on caries lesion de- and remineralization.
abstract: This study investigated the effects of lesion baseline characteristics and different strontium (Sr) to calcium (Ca) ratios in plaque fluid-like solutions (PF) on lesion de- and remineralization. Caries lesions were formed in enamel using three protocols: methylcellulose acid gel (MeC) and partially saturated lactic acid solutions containing carboxymethylcellulose (CMC) or not (SOLN). Lesions were exposed to PF with four distinct Sr:Ca molar ratios (0:1/3:1:3), but otherwise identical composition and total Sr+Ca molarity, for seven days. Lesions were characterized using transverse microradiography (TMR) at baseline and post-treatment. At baseline, MeC and CMC had similar integrated mineral loss values, whereas SOLN lesions were more demineralized. All lesions showed significant differences in their mineral distributions, with CMC and SOLN having lower R values (integrated mineral loss to lesion depth ratio) than MeC. Post-PF exposure, no interaction was found between lesion type and Sr:Ca ratio. Within lesion type, MeC demineralized, whereas CMC and SOLN exhibited some remineralization, with the differences between MeC and the other lesion types being of statistical significance. Within Sr:Ca ratio, the 1:3 ratio exhibited some remineralization whereas other groups tended to demineralize. Only the difference between groups SrCa1/3 and SrCa0 was of statistical significance. In summary, both lesion baseline characteristics and Sr:Ca ratio were shown to effect lesion de- and remineralization. Under the conditions of the study, high-R lesions are more prone to demineralize under PF-like conditions than low-R lesions. In addition, partial Sr substitution for Ca in PF was shown to enhance lesion remineralization.
authors.affiliation: Department of Preventive and Community Dentistry, Oral Health Research Institute, Indiana University School of Dentistry, 415 Lansing Street, Indianapolis, IN 46202, USA. flippert@iupui.edu
authors.forename: Frank
authors.initials: F
authors.lastname: Lippert
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002122:Calcium Chloride / Q000737:chemistry / Q000494:pharmacology*; D002417:Cattle; D003731:Dental Caries / Q000139:chemically induced / Q000188:drug therapy*; D003773:Dental Plaque / Q000737:chemistry*; D066298:In Vitro Techniques; D019344:Lactic Acid; D008747:Methylcellulose; D008852:Microradiography; D012996:Solutions / Q000737:chemistry; D013324:Strontium / Q000737:chemistry / Q000494:pharmacology*; D017001:Tooth Demineralization / Q000139:chemically induced / Q000188:drug therapy*; D014089:Tooth Remineralization / Q000379:methods*
chemical_list: D012996:Solutions; D019344:Lactic Acid; D008747:Methylcellulose; D002122:Calcium Chloride; D013324:Strontium