Effect of chlorhexidine-fluoride applications without and with Sr and Zn on caries, plaque, and gingiva in rats

Molar teeth of four groups of Osborne-Mendel rats, kept on a cariogenic diet, were treated once per day for 48 days with either distilled water (solution C), a solution containing 0.05% chlorhexidine gluconate and 0.04% NaF, pH 5.8 (solution CXF), CXF plus 1000 ppm Sr (solution CXFS), or CXFS plus 1000 ppm Zn (solution CXFSZ). Caries of the hemi-sectioned lower molars was scored according to grades of severity, and the extent of the buccal plaque was estimated. Inflammatory cell infiltration, vascularity, and thickness of the oral mucosa were estimated from stained sections of the buccal oral mucosa to detect possible adverse effects of the treatments. Fissure caries lesions with involvement of the dentin were reduced by 57% (p less than 0.01) with the CXF treatment and by 68% (p less than 0.001) with the CXFS treatment. The CXFSZ treatment reduced the fissure caries least (44%, p less than 0.05), but it appreciably reduced the extent of plaque. The mucosal changes were greatest in the group receiving the CXFSZ treatment, but they were generally small and at a non-pathological level. Supplementation of the CXF solution with Sr thus appeared beneficial for caries reduction.