Reactions of dental pulp to hydrogen peroxide photolysis-based antimicrobial chemotherapy under ultraviolet-A irradiation in rats
Reactions of dental pulp to hydrogen peroxide photolysis-based antimicrobial chemotherapy under ultraviolet-A irradiation in rats
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DOI：
10.1016/j.jphotobiol.2020.112042
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发表时间：
2020-11-01
影响因子：
5.4
通讯作者：
Ortengren, Ulf
中科院分区：
文献类型：
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作者：
Nakamura, Keisuke;Shirato, Midori;Ortengren, Ulf
先前已提出利用紫外线-A照射（UVA-H2 O2光解）的基于过氧化氢光解的抗微生物化学疗法作为治疗致龋生物膜的方法。因此，在本研究中，我们的目的是评估时间依赖性的反应，在大鼠牙髓后，UVA-过氧化氢光解。治疗上颌第一磨牙。UVA照射（波长：365 nm）和3wt%H2O2的光致抗蚀剂，辐射率为500-2000 mW/cm（2），持续90 s，连续3天或仅1天。在治疗后第1、3、7和21天处死动物，进行炎性细胞的组织学评价和成牙本质细胞标记物热休克蛋白（HSP）-25的免疫组化。在第21天通过组织形态计量学和显微CT分析评价三级牙本质形成。UVA-H2 O2光解引起炎症细胞浸润很少，但在第3天观察到成牙本质细胞层紊乱和/或局部退行性组织的存在。这种情况之后是愈合过程，其特征在于HSP-25阳性成牙本质细胞样细胞在第7天的再现和第21天的三级牙本质形成。三级牙本质形成的数量取决于处理的强度;在2000 mW/cm 2的H2 O2的UVA重复照射下，髓角区域三级牙本质形成的数量最多。我们的研究结果表明，UVA-H2 O2光解治疗可以用于临床治疗龋齿，因为治疗后的炎症反应最小，三级牙本质形成是实质性的，这可能被证明是有效的保护牙髓免受外部刺激。作为一个谨慎的考虑，UVA照射的辐射发射率应在临床应用前仔细优化。
Hydrogen peroxide photolysis-based antimicrobial chemotherapy that utilizes ultraviolet-A irradiation (UVA-H2O2 photolysis) has been previously proposed as a method of treatment of cariogenic biofilm. Therefore, in the present study, we aimed to assess time-dependent reactions in the dental pulp of rats after UVA-H2O2 photolysis. Maxillary first molars were treated. UVA irradiation (wavelength: 365 nm) with 3 wt% H2O2 was performed for 90 s at a radiant emittance of 500-2000 mW/cm(2) on the rats for 3 consecutive days or only 1 day. The animals were sacrificed at Days 1, 3, 7, and 21 after the treatment for the histological evaluation of inflammatory cells and immunohistochemistry of heat shock protein (HSP)-25, a marker of odontoblasts. Tertiary dentin formation was evaluated at Day 21 by histomorphometry and micro-CT analysis. UVA-H2O2 photolysis elicited little infiltration of inflammatory cells, but disturbances in the odontoblast layer and/or presence of localized degenerative tissue were observed on Day 3. This condition was followed by a healing process that was characterized by the reappearance of HSP-25 positive odontoblast-like cells at Day 7 and tertiary dentin formation at Day 21. The amount of tertiary dentin formed was dependent on the intensity of treatment; repeated UVA irradiations of H(2)O(2 )at 2000 mW/cm(2) resulted in the largest amount of tertiary dentin formation at the pulp horn regions. Our findings suggest that UVA-H2O2 photolysis treatment can be used to treat dental caries clinically because the post-treatment inflammatory reaction was minimal and tertiary dentin formation was substantial, which may prove effective in protecting dental pulp from external irritants. As a cautionary consideration, the radiant emittance of the UVA irradiation should be carefully optimized before clinical application.