【摘要】 目的:观察光动力疗法(photodynamic therapy,PDT)对牙骨质龋的抑制效果。方法:将50个牙骨质块与粘性放线菌、变异链球菌和乳酸杆菌的混合菌液共同培养24 d,成功建立牙骨质早期龋模型后随机分为5组(单纯光敏剂组、单纯激光照射组、PDT组、洗必泰阳性对照组、生理盐水阴性对照组,n=10)。按分组进行相应处理后,采用平板菌落计数观察杀菌效果;然后再将各组样本置于新鲜培养液中进行培养,分别于培养8、16、24、32、40、48 h各时间点取各组培养液,用原子吸收光谱法测量其中的钙离子含量。结果:与阴性对照组相比,PDT可使牙骨质龋样本中的致龋菌数量显著减少(P<0.05),其杀菌率为98.70%,明显高于其他各组(P<0.05);各组钙离子溶出量均随培养时间延长而增加,其中以PDT组的增加幅度最小,各时间点的钙离子溶出量均显著低于其他各组(P<0.05)。结论:光动力疗法对牙骨质龋有一定的抑制作用。更多还原

【Abstract】 AIM:To observe the inhibiting effect of photodynamic therapy( PDT) on cementum caries. METHODS:50 cementum blocks were cultured with mixed suspension of A. Viscosus,S. mutans and L. acidophilus for 24 d to develop caries. The blocks with caries were then divided into 5 groups( n = 10) :photosensitizer group( L-P +),laser group( L + P-),PDT group( L + P +),0. 5 g/L chlorhexidine group( positive control) and normal saline group( negative control). After respective treatment,the cementum blocks were put into 1 mL saline and stirred for 3 min. the solutions were then serially diluted and cultured in plates for 48 h. Bacteriacidal effects of the treatment was measured by colony-forming unit( CFU) counting. The blocks were further put into 6 mL culture medium and cultured anaerobically. At 8 h,16 h,24 h,32 h,40 h and 48 h of culture,1 mL suspension was withdrawn and subjected to atomic absorption spectrometry for the measurement of the calcium ion content. RESULTS:The bacterialcidal effect of PDT was 98. 70%,which was significantly higher than that of photosensitizer( 1. 23%,P < 0. 05),laser( 56. 96%, P < 0. 05),positive control( 60. 62%,P < 0. 05) and negative control( 0%,P < 0. 05). Calcium dissolution increased with time in all groups. However,PDT group showed the least calcium dissolution( P < 0. 05). CONCLUSION:PDT may inhibit the develpment of cementum caries.更多还原