In vitro evaluation of the effect of bleaching dentifrices containing blue covarine on bovine dental enamel

Abstract Introduction Blue covarine is a bleaching agent that produces optical changes on the surface of the teeth, associated with the abrasives of the dentifrice leading to tooth whitening. Objective To determine the changes in colour, roughness and mass of the bovine enamel, after simulated brushing with dentifrices - containing blue covariate bleaching - for 6, 12 and 24 months. Material and method 80 specimens were divided into 8 groups (n = 10): Control group (CG-water) and 7 test groups (TG1-Colgate Total 12, TG2-Oral-B 3D White Perfection, TG3 -Colgate Luminous Instant White, TG4-Close Up White Diamond Attraction, TG5-Close Up White Now-Glacier Fresh, TG6-Sorriso Xtreme White, TG7-Colgate Luminous White Advanced). The specimens were stained with coffee and subjected to simulated brushing for 6, 12 and 24 months. The colour, roughness and mass evaluations were performed after each brushing period. Result No dentifrice test produced significant alterations in the roughness and mass of the specimens, however, when compared to CG, all of themproduced significant whitening. The comparison of the test groups did not show a significant difference in the colour variation between TG1, TG2, TG3, TG5, TG6 and TG7 in the study. The TG4 presented a variable behavior according to time, not statistically differing from TG3 at 6, 12 and 24 months, neither from TG6 at 6 and 12 months nor from TG7 at 12 months. Conclusion The whitening effect of dentifrices containing blue covarine, after long periods of brushing, seems to be related mainly to association with mechanical bleaching agents, which, despite abrasives, did not damage the dental structure.摘要与引言：蓝色柯瓦林（blue covarine）是一种可在牙齿表面引发光学变化的漂白剂，其与牙膏中的磨料协同作用，可实现牙齿美白。 研究目的：探究添加蓝色柯瓦林的牙膏经6、12、24个月模拟刷牙后，牛牙釉质（bovine enamel）的色泽、粗糙度及质量变化。 材料与方法：选取80个牛牙釉质样本，随机分为8组（每组n=10）：对照组（CG，去离子水组）及7个试验组，分别为TG1：高露洁全效12（Colgate Total 12）、TG2：欧乐B 3D炫白臻效（Oral-B 3D White Perfection）、TG3：高露洁莹亮瞬白（Colgate Luminous Instant White）、TG4：洁诺钻白焕亮牙膏（Close Up White Diamond Attraction）、TG5：洁诺洁白冰川清新款（Close Up White Now-Glacier Fresh）、TG6：索里索极致美白牙膏（Sorriso Xtreme White）、TG7：高露洁莹亮卓效白牙膏（Colgate Luminous White Advanced）。所有样本经咖啡染色后，接受6、12、24个月的模拟刷牙处理，于每个刷牙周期结束后分别检测样本的色泽、粗糙度及质量。 研究结果：所有受试牙膏均未对样本的粗糙度及质量产生显著影响，但与对照组相比，所有试验组均实现了显著的牙齿美白效果。组间比较显示，TG1、TG2、TG3、TG5、TG6及TG7之间的色泽变化无统计学差异。TG4的美白效果随时间呈现动态变化，其在6、12、24个月时与TG3无统计学差异，6、12个月时与TG6无统计学差异，12个月时与TG7无统计学差异。 研究结论：长期使用添加蓝色柯瓦林的牙膏，其美白效果主要与机械漂白剂的协同作用相关；尽管含有磨料，但并未对牙齿结构造成损伤。