|
The purposes of this study were to compare a microbial model and a chemical pH cycling model for the remineralization. Two test dentifrices, NaF-silica abrasive system with and without sanguinaria were used in this study to delineate the antiplaque effect via microbial model. Subsurface lesion were prepared by exposing bovine enamel specimens to a lactate Carbopol buffer system for 44 hours. The three test groups were placebo, NaF-silica abrasive dentifrices with and without 0.1% sanguinaria, The specimens were assigned to 6 test groups of 12 specimens each by randomized blocks with VHN stratification. The microbial remineralization model was used as described previously(Hong et al. 2)). The chemical model used in this study was a modification of the method of White29). The specimens were treated for 15 days with either chemical or microbial remineralization model. Pre and post- surface VHN values were randomly obtained. Once the results were decoded by test groups, the D VHN values were determined. The results of A VHN(mean ± S.D.) for each group were; For chemical model: 9.5 ± 5.0(placebo, No Fluoride/silica abrasive); 68.3 ± 6.2(1,000ppm F, NaF/silica abrasive); 70A± 5.8(1,000ppm F NaF plus 0.1% sanguinaria/silica abrasive); For microbial Model: 18.4 ± 7.2(Placebo, No Fluoride/silica abrasive); 33.5 ± 10.4(1,000ppm F, NaF/silica abrasive); 42.3 ±9.2(1,000ppm F, NaF plus 0.1% sanguinaria/silica abrasive). Statistical analyses. of. these results indicated that NaF-silica dentifrice without sanguinaria was as effective as that with sanguinaria on surface hardening in chemical model. However, NaF-silica dentifrice with sanguinaria was more effective than that of without sanguinaria in microbial model, indicating the benefit of sanguinaria. Therefore, it is concluded that the microbial model used in this study is suitable for the testing of remineralization benefit of the dentifrices containing antiplaque agents.
|