不同功率密度HMME-PDT对致龋模型防龋效果的影响

摘要

AIM: To evaluate the inhibitive effect of photodynamic therapy(PDT) with different power density on dental caries formation in rats.METHODS:56 Wistar rats (aged 21 days) were infected with S.mutans for the establishment of rat caries mode1s and then divided in to 7 groups(n=8).As controls, the rat''s teeth were treated with 9 mL/L NS, and 2 g/L NaF respectively.The laser, hematoporyrin monomethyl ether(HMME) and laser plus HMME were respectively used to treat the teeth in the treatment groups, The rats'' teeth were treated once a week for 4 weeks.Then the rats were sacrificed and Keyes count method was used to evaluare the inhibitory effect of PDT on dental caries.RESULTS: The PDT-treated teeth and NaF-treated teeth showed significantly reduced Keyes scores than the negative controls, laser-treated and HMME-treated teeth(P<0.05).Keyes scores of 70 mw/cm2 HMME-PDT group was higher than that of NaF-treated teeth (P<0.05).Keyes scores of 140 mw/cm2 HMME-PDT group was the same as that of NaF-treated group(P>0.05), Keyes scores of 280 mw/cm2 HMME-PDT group was less than that of NaF-treated group (P<0.05).Keyes scores reduced with the increase of the laser power dentistry.CONCLUSION: HMME-PDT may inhibite caries development in a laser power density dependent manner.%目的:观察以血卟啉单甲醚(HMME)为光敏剂的不同功率密度光动力疗法(PDT)对大鼠致龋模型防龋效果的影响.方法:取21 d龄Wistar大鼠56只,并通过口腔接种变异链球菌而建立致龋模型后,将其随机分为7组(n=8),分别为:3个不同功率密度(70、140、280 mw/cm2 HMME-PDT)光动力组、单纯激光照射组、单纯光敏剂组、9 mL/L生理盐水(阴性对照)组、2 g/L氟化钠(阳性对照)组.然后按上述分组对各大鼠的上下颌磨牙进行相应处理;每周处理1次,连续4周后处死所有大鼠,用Keyes法记分并评价各组的防龋效果.结果:不同功率密度PDT组和氟化钠组的Keyes记分均明显低于生理盐水组、单纯激光照射组、单纯光敏剂组(P<0.05);Keyes记分结果显示,70 mw/cm2 组明显高于氟化钠组 (P<0.05),140 mw/cm2 组与氟化钠组相近(P>0.05),280 mw/cm2 组明显低于氟化钠组 (P<0.05).表现为:随着功率密度的增加,其Keyes记分呈逐渐降低的趋势.结论:HMME-PDT对大鼠龋损有明显的防治作用,其效果与功率密度密切相关.