RESUMO
ObjectiveTo evaluate the inhibitive effect of Photodynamic therapy (PDT) with different parameters on dental caries formation in rats.MethodsWistar rats were infected with S.mutans to establish the rat caries mode 1.The rat's teeth were treated with 0.9% NS and 0.2% NaF as controls;laser,photosensitizer and laser plus photosensitizer,respectively as treated groups.Hematoporyrin monomethyl ether(HM ME) was used as photosensitizer and laser as the light source.The rats were sacrificed after five weeks.Keyes count was used to measure the inhibitory effect of PDT on dental caries.The surface morphology of the teeth was evaluated by scan electronic microscopy(SEM).Results The PDT-treated group and NaF-treated group showed significantly reduced Keyes scores compared with the negative controls (P＜0.05).The laser-treated group,photosensitizer-treated group and NS-treated group showed no significantly reduced Keyes scores compared with the negative controls (P＜0.05).The differences of Keyes scores between various parameter PDT treated groups were significant (P＜0.05).Additionally,Keyes scores reduced gradually with the increasing of laser power.The outcome of SEM showed that the teeth treated with different laser powers exhibited different changes in morphology.Conclusion HMMEPDT had significant inhibitive efficacy on caries development in rats and its inhibitory effect presented close correlation with the power of laser,which indicates that it is important to apply appropriate power in clinical treatment.
