Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Department of Pediatric Dentistry, Hospital of Stomatology, Jilin University, Changchun, Jilin, China.
Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Department of Dental Implantology, Hospital of Stomatology, Jilin University, Changchun, Jilin, China.
Front Endocrinol (Lausanne). 2023 Aug 3;14:1192420. doi: 10.3389/fendo.2023.1192420. eCollection 2023.
Dexamethasone (DEX) exerts anti-inflammatory and osteogenic effects. Hydroxyapatite is commonly used in bone repair due to its osteoconductivity, osseointegration, and osteogenesis induction. Hollow hydroxyapatite (HHAM) is often used as a drug carrier.
This study aimed to investigate the histological responses of exposed dental pulp when dexamethasone-loaded nanohydroxyapatite microspheres (DHHAM) were used as a direct capping agent.
Cavities were created in the left maxillary first molar of Wistar rats and filled with Dycal, HHAM, and DHHAM. No drug was administered to the control group. The rats were sacrificed at 1, 2, and 4 weeks after the procedure. The molars were extracted for fixation, demineralization, dehydration, embedding, and sectioning. H&E staining was performed to detect the formation of reparative dentin. H&E and CD45 immunohistochemical staining were performed to detect pulp inflammation. Immunohistochemical staining was performed to assess the expressions of dentin matrix protein 1 (DMP-1), interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β.
The results of H&E and CD45 immunohistochemical staining showed that the degree of inflammation in the DHHAM group was less than that in the Control and HHAM groups at 1, 2, and 4 weeks after capping of the rat molar teeth (p<0.01). The H&E staining showed that the percentage of reparative dentin formed in the DHHAM group was higher than that in the Control, HHAM (p<0.001), and Dycal groups (p<0.01) at 1 and 2 weeks, and was significantly higher than that in the Control group (p<0.001) and the HHAM group (p<0.01) at 4 weeks. The immunohistochemical staining showed a lower range and intensity of expression of IL-1β, IL-6, and TNF-α and high expression levels of DMP-1 in the DHHAM group at 1, 2, and 4 weeks after pulp capping relative to the Control group.
DHHAM significantly inhibited the progression of inflammation and promoted reparative dentin formation.
地塞米松（DEX）具有抗炎和成骨作用。由于具有骨传导性、骨整合性和成骨诱导性，羟基磷灰石常用于骨修复。中空羟基磷灰石（HHAM）通常用作药物载体。
本研究旨在探讨将载地塞米松纳米羟基磷灰石微球（DHHAM）用作直接盖髓剂时，暴露牙髓的组织学反应。
在 Wistar 大鼠左侧上颌第一磨牙上制备窝洞，并用 Dycal、HHAM 和 DHHAM 填充。对照组不给予药物。程序后 1、2 和 4 周处死大鼠。提取磨牙进行固定、脱矿、脱水、包埋和切片。进行 H&E 染色以检测修复性牙本质的形成。进行 H&E 和 CD45 免疫组织化学染色以检测牙髓炎症。进行免疫组织化学染色以评估牙本质基质蛋白 1（DMP-1）、白细胞介素（IL）-6、肿瘤坏死因子（TNF）-α和 IL-1β的表达。
H&E 和 CD45 免疫组织化学染色结果显示，在大鼠磨牙盖髓后 1、2 和 4 周，DHHAM 组的炎症程度低于对照组和 HHAM 组（p<0.01）。H&E 染色显示，DHHAM 组在 1 和 2 周形成的修复性牙本质百分比高于对照组、HHAM 组（p<0.001）和 Dycal 组（p<0.01），在 4 周时明显高于对照组（p<0.001）和 HHAM 组（p<0.01）。免疫组织化学染色显示，在牙髓盖髓后 1、2 和 4 周，DHHAM 组的 IL-1β、IL-6 和 TNF-α表达范围和强度较低，DMP-1 表达水平较高。
DHHAM 可显著抑制炎症进展，促进修复性牙本质形成。
