Abstract:Objective: To Study the inhibitory effect of TBO-PDT in different photosensitizer concentration and different lighting time on the cariogenic bacteria in dental plaque biofilms of rats, and determine the optimal photosensitizer parameters and time parameters. On the basis of this, to discuss the advantages of TBO-PDT in inhibiting the biofilm of mixed bacterial plaque, and provided theoretical and experimental evidence for the application of PDT in the prevention of dental caries and to provid theoretical and experimental basis for the application of PDT for dental caries prevention. Method: The caries model was constructed with Wistar rats. All the rats in accordance with the principle of randomization were divided into groups as follows:Group A :a saline - negative treatment group;Group B:a positive control group for chlorhexidine. The other groups were based on the concentration of the photosensitizer as group C1:60mg/L, group D1:80mg/L, group E1:100mg/L, group F1:120mg/L, group G1:140mg/L. Treated group C1-G1 with incubation for 5 minutes in dark place and exposed 9min by a semiconductor laser with a wavelength of 630nm. The output strength was 105 mW/cm2. The rest groups were based on the exposure time:group C2:3min; group D2:6min; group E2:9min; group F2:12min; group G2:15min. Treated group C2-G2 with incubation for 5 minutes in dark place and exposed by a semiconductor laser with a wavelength of 532nm. The photosensitizer concentration was 100mg/L. The output strength was 105mW/cm2. According to the different exposure time, it was divided into C2 group 3min, D2 group 6min, E2 group 9min, F2 group 12min, G2 group 15min, and the photosensitizer concentration was 100mg/L after incubating 5min, and the output intensity was 105 diode laser. The inhibitory effect of TBO-PDT on oral mixed bacteria biofilm of rat oral mixed bacteria was evaluated by atomic absorption spectrophotometer, and the inhibitory effect of TBO-PDT on oral mixed bacterial plaque biofilm was evaluated by atomic absorption spectrophotometer. Resultes: The bacteriostatic effect of TBO-PDT on bacterial plaque in rat oral cavity was studied in different concentration of photosensitizer. The tablet colony count results showed with the increase of concentration of photosensitizer stress the bacteria inhibitive rate was increased. Compared to the negative control group and positive control group, bacteria inhibitive rate of group C1, group D1, group E1, group F1 and group G1 changed most obviously. Bacteria inhibitive rate of group E1, group F1 and group G1 were increased than positive control group. The bacteriostatic effect of TBO-PDT on bacterial plaque in rat oral cavity was studied in different exposure time. The tablet colony count results showed with the increase of exposure time the bacteria inhibitive rate was increased. Compared to the negative control group, bacteria inhibitive rate of group C2, group D2, group E2, group F2 and group G2 changed most obviously. Bacteria inhibitive rate of group E2, group F2 and group G2 were increased than positive control group. Results of the calcium ion dissolution detected by atomic absorption spectrophotometer showed with the increase of exposure time the calcium ion dissolution was increased in each group in 48 hours. Compared to the negative control group, the calcium ion dissolution of each group was decreased significantly (P<0.05). Compared to the negative control group, the calcium ion dissolution of each group was decreased. However, there was no significant difference between them (P>0. 05). Conclusion: TBO-PDT has obvious inhibitory effect on the biofilm of mixed bacteria plaque in rats. The results showed that the best photosensitizer concentration of TBO-PDT was 100 g/mL and the best illumination time was 9min. Photodynamic therapy can effectively inhibit the cariogenic bacteria in the bacterial plaque biofilm of rats, reduce the amount of calcium ion dissolution in early caries, not only prevent the continued demineralization of the enamel, but also promote the remineralization of the enamel. PDT has broad clinical application prospects in the prevention of dental caries.
陶亚东, 孙继红, 柳雪, 王鹏, 霍峰. TBO-PDT对大鼠口腔混合菌生物膜抑制作用的实验研究[J]. 河北医学, 2018, 24(7): 1187-1193.
TAO Yadong, et al. The Experimental Study on the Inhibitory Effect of TBO-PDT on Biofilm of Oral Mixed Bacteria in Rats. HeBei Med, 2018, 24(7): 1187-1193.
[1] Lilburn TG, Gu J, Cai H, et al. Comparative genomics of the family Vibrionaceae reveals the wide distribution of genesencod in virulence-associated proteins[J]. BMC Genomics, 2010, 10(11):369~372. [2] 常秀明,邹朝晖,阴慧娟,等.光动力疗法对牙菌斑生物膜内致龋菌的影响及作用机制的研究[J].口腔医学研究,2012,28(4):303~309. [3] Souza L, Brito P, Oliveira J, et al. Photodynamic therapy with two different photosensitizers as supplement to instrumentation irrigation procedures in promoting intracanal reduction of Enterococcus faecalis. [J] Endod, 2010, 36(2): 292~296. [4] Michael Wilson. L et al photosensitization of oral bacteria and its potential application in the photodynamic therapy of oral in fections[J] Photochem Photobiol Sci, 2004,3(5):412~418. [5] Soukos NS, Wilson M, Burns T, et al. Photodynamic effects of toluidine blue on human oral keratinocytes and fibroblasts and Streptococcus sanguis evaluated in vitro[J].Lasers Surg Med. 1996; 18(3):253~259. [6] Soares B M,da-Silva D L,Sousa G R et al. In vitro photodynamic in activation of Candida spp. growth and adhesion to buccal epithelial cells [J]. Photochem Photobiol B,2009,94( 1) : 65~70. [7] 许小辉,林居红,刘明方.光动力学疗法影响人工菌斑生物膜形成的扫描电镜观察[J]第三军医大学学报,2010,32(21):2314~2317.