Department of Restorative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
Microsc Res Tech. 2010 Oct;73(11):1030-5. doi: 10.1002/jemt.20827.
It remains uncertain as to whether or not CO(2) laser is able to hinder demineralization of enamel. The possibility to use bovine instead of human teeth on anticariogenic studies with laser has not yet been determined.
To compare the ability of CO(2) laser and fluoride to inhibit caries-like lesions in human enamel and to test whether a similar pattern of response would hold for bovine enamel.
Ninety-six enamel slabs (2 × 2 × 4 mm) (48 from bovine and 48 from human teeth) were randomly distributed according to surface treatment (n = 12): CO(2) laser, 5% sodium fluoride varnish (FV), 1.23% acidulated phosphate fluoride (APF) gel, or no treatment (control). Specimens were subjected to a 14-day in vitro cariogenic challenge. Microhardness (SMH) was measured at 30 μm from the surface. For ultrastructural analysis, additional 20 slabs of each substrate (n = 5) received the same treatment described earlier and were analyzed by SEM.
ANOVA and Tukey test ascertained that CO(2) laser promoted the least mineral loss (SMH = 252(a)). Treatment with FV resulted in the second highest values (207(b)), which was followed by APF (172(c)). Untreated specimens performed the worst (154(d)). SEM showed no qualitative difference between human and bovine teeth. APF and control groups exhibited surfaces covered by the smear layer. A granulate precipitate were verified on FV group and fusion of enamel crystals were observed on lased-specimens.
CO(2) laser may control caries progression more efficiently than fluoride sources and bovine teeth may be a suitable substitute for human teeth in studies of this nature.
目前尚不确定二氧化碳激光是否能够阻止牙釉质脱矿。在抗龋研究中，使用牛牙而不是人牙的可能性尚未确定。
比较二氧化碳激光和氟化物抑制人牙釉质龋样病变的能力，并检验牛牙釉质是否具有类似的反应模式。
96 个牙釉质薄片（2×2×4mm）（48 个人类和 48 个牛牙）根据表面处理随机分配（n=12）：二氧化碳激光、5%氟化钠涂料（FV）、1.23%酸性磷酸氟化物凝胶或无处理（对照）。标本进行 14 天体外致龋挑战。在距表面 30μm 处测量显微硬度（SMH）。为了进行超微结构分析，每个基底的另外 20 个薄片（n=5）接受了前面描述的相同处理，并通过 SEM 进行分析。
方差分析和 Tukey 检验确定二氧化碳激光促进的矿物质损失最少（SMH=252(a)）。FV 处理的结果为第二高值（207(b)），其次是 APF（172(c)）。未处理的标本表现最差（154(d)）。SEM 显示人类和牛牙之间没有质的区别。APF 和对照组显示表面覆盖有玷污层。FV 组观察到颗粒状沉淀物，激光处理组观察到牙釉质晶体融合。
二氧化碳激光可能比氟化物源更有效地控制龋病进展，并且牛牙可能是此类研究中替代人牙的合适替代物。
