Zuo Jing, Zhen Jiaxiu, Wang Fei, Li Yueheng, Zhou Zhi
College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China.
College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China.
Ultrasound Med Biol. 2018 Jan;44(1):223-233. doi: 10.1016/j.ultrasmedbio.2017.09.006. Epub 2017 Oct 24.
Low-intensity pulsed ultrasound (LIPUS) is known for its positive effect on bone healing and reparative regeneration. This study investigated whether LIPUS affects reparative progression of the tooth and the expression of calcium ion transport-related proteins in odontoblasts and dental pulp cells using a rat dentin-pulp complex injury model. Forty male adult Sprague-Dawley rats underwent cavity preparation in the right maxillary first molar: 20 received LIPUS irradiation on the cavity-prepared tooth; 20 received LIPUS irradiation on the left maxillary first molar. Rats were randomly allocated into four groups: blank control group, LIPUS group, cavity-prepared group, cavity-prepared + LIPUS group. LIPUS irradiation (frequency: 1.5 MHz, 200-µs pulse width, 1-kHz pulse repetition frequency, 30 mW/cm spatial averaged temporal averaged intensity) was administered individually for 20 min daily. Rats were sacrificed 1, 3, 7 and 14 d post-operation. The histopathological and cellular morphologic changes in the dentin-pulp complex were detected with hematoxylin and eosin staining. Expression of calcium ion transport-related proteins (Cav1.2, NCX1 and TRPV1) was determined with immunohistochemical staining and imaging analysis. Histopathological analysis revealed obvious reparative dentin formation at day 14 in the cavity-prepared + LIPUS group compared with the other groups. Expression levels of Cav1.2, NCX1 and TRPV1 increased significantly by 22%, 53% and 23%, respectively, at day 1 and increased significantly by 23%, 27% and 22%, respectively, at day 3 in the cavity-prepared + LIPUS group (p <0.05) compared with the cavity-prepared group. LIPUS has a positive effect on the expression of calcium transport-related proteins during early-stage dentin injury and facilitates tertiary dentin formation; the mechanism for this likely relates to the inflammatory reaction and a mechanical effect.
低强度脉冲超声（LIPUS）因其对骨愈合和修复性再生的积极作用而闻名。本研究使用大鼠牙本质-牙髓复合体损伤模型，研究LIPUS是否影响牙齿的修复进程以及成牙本质细胞和牙髓细胞中钙离子转运相关蛋白的表达。40只成年雄性Sprague-Dawley大鼠在上颌右侧第一磨牙进行开髓：20只在开髓后的牙齿上接受LIPUS照射；20只在上颌左侧第一磨牙接受LIPUS照射。大鼠被随机分为四组：空白对照组、LIPUS组、开髓组、开髓+LIPUS组。LIPUS照射（频率：1.5MHz，脉冲宽度200μs，脉冲重复频率1kHz，空间平均时间平均强度30mW/cm²）每天单独进行20分钟。术后1、3、7和14天处死大鼠。用苏木精和伊红染色检测牙本质-牙髓复合体的组织病理学和细胞形态学变化。用免疫组织化学染色和图像分析测定钙离子转运相关蛋白（Cav1.2、NCX1和TRPV1）的表达。组织病理学分析显示，与其他组相比，开髓+LIPUS组在第14天有明显的修复性牙本质形成。与开髓组相比，开髓+LIPUS组在第1天Cav1.2、NCX1和TRPV1的表达水平分别显著增加22%、53%和23%，在第3天分别显著增加23%、27%和22%（p<0.05）。LIPUS对早期牙本质损伤期间钙离子转运相关蛋白的表达有积极作用，并促进第三期牙本质形成；其机制可能与炎症反应和机械效应有关。
