Department of Restorative Dentistry, Division of Endodontics, Piracicaba Dental School - State University of Campinas - UNICAMP, Av. Limeira 901. Bairro Areião, Piracicaba, São Paulo, Brazil.
Clin Oral Investig. 2019 Jun;23(6):2759-2766. doi: 10.1007/s00784-018-2719-0. Epub 2018 Oct 26.
The objective of this work was to investigate in vivo the effects of calcium hydroxide-based intracanal medication (ICM) on the levels of bacteria, pro-inflammatory cytokines (PICs), and matrix metalloproteinases (MMPs) in root canals and periradicular tissues of teeth with failure of the root canal treatment and apical periodontitis.
Twenty infected root canals of single-rooted teeth were randomly assigned into two groups according to the irrigant used for chemomechanical preparation (CMP) (n = 10 per group): G1 - 2% chlorhexidine (CHX) gel and G2 - 6% sodium hypochlorite (NaOCl). Root canal contents were taken by using paper points before CMP (S1) and after 30 days of calcium hydroxide-based ICM (S2). Microbial reduction was calculated by means of colony-forming unit count (CFU/mL), with PICs and MMPs (pg/mL) being measured by using enzyme-linked immunosorbent assay (ELISA).
Culturable bacteria (101.2 ± 79.2), PICs (IL-1β 1.2 ± 0.4 and TNF-α 8.8 ± 4.7), MMP-2 (803.7 ± 96.4), MMP-3 (453.9 ± 229.3), MMP-8 (245.9 ± 122.4), MMP-9 (129.4 ± 29.6), and MMP-13 (70.8 ± 12.8) were present in all S1 samples. After 30 days of ICM (S2), a 99.5% microbial reduction was observed, together with a significant reduction of PICs in all groups. Overall, it was observed a decrease in the levels of MMPs (S2), except MMP-13, which was found in increased levels after ICM (P < .05), independently of the groups.
Calcium hydroxide-based intracanal medications have had a positive effect on the microbial reduction by decreasing the levels of PICs and MMPs. Both auxiliary chemical substances (i.e., 2% CHX and 6% NaOCl) presented similar effects when calcium hydroxide was used as intracanal medication.
Teeth with failure of the root canal treatment and apical periodontitis, and consequently with high levels of bacteria, PIC, and MMP, may present a better prognosis after a 30 days of a calcium hydroxide-based ICM.
本研究旨在体内研究氢氧化钙根管内用药（ICM）对根管治疗失败伴根尖周炎患牙根管内和根尖周组织中细菌、促炎细胞因子（PICs）和基质金属蛋白酶（MMPs）水平的影响。
将 20 个感染的单根牙根管随机分为两组，根据化学机械预备（CMP）所用冲洗剂进行分组（每组 n=10）：G1-2%洗必泰（CHX）凝胶和 G2-6%次氯酸钠（NaOCl）。在 CMP 前（S1）和使用氢氧化钙 ICM 30 天后（S2）使用纸尖采集根管内容物。通过菌落形成单位计数（CFU/mL）计算微生物减少量，并通过酶联免疫吸附试验（ELISA）测量 PICs 和 MMPs（pg/mL）。
所有 S1 样本中均存在可培养细菌（101.2±79.2）、PICs（IL-1β 1.2±0.4 和 TNF-α 8.8±4.7）、MMP-2（803.7±96.4）、MMP-3（453.9±229.3）、MMP-8（245.9±122.4）、MMP-9（129.4±29.6）和 MMP-13（70.8±12.8）。在 ICM 30 天后（S2），观察到 99.5%的微生物减少，同时所有组的 PICs 均显著减少。总体而言，除 MMP-13 外，所有 MMPs（S2）水平均降低，但在 ICM 后发现 MMP-13 水平升高（P<.05），这与组无关。
氢氧化钙根管内用药通过降低 PICs 和 MMPs 水平对微生物减少产生了积极影响。当氢氧化钙用作根管内用药时，两种辅助化学物质（即 2% CHX 和 6% NaOCl）均具有相似的效果。
根管治疗失败伴根尖周炎的患牙，细菌、PIC 和 MMP 水平较高，经 30 天氢氧化钙 ICM 治疗后可能具有更好的预后。
