Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida do Café s/n, Monte Alegre, Ribeirão Preto, SP, 14040-904, Brazil.
Department of Oral Pathology, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil.
Clin Oral Investig. 2017 Dec;21(9):2851-2861. doi: 10.1007/s00784-017-2087-1. Epub 2017 Mar 9.
The objective of the present study is to evaluate the in vitro cytotoxicity and in vivo biocompatibility of two novel endodontic sealers: RealSeal XT1 and Sealapex Xpress on the subcutaneous connective tissue of mice.
The cytotoxicity was assessed by cell viability using the MTT assay (one-way ANOVA), trypan blue test (Mann-Whitney) and cell apoptosis by flow cytometer. For the subcutaneous study, polyethylene tubes filled with the sealers were implanted in 70 BALB/c mice: 6 experimental groups (n = 10/group) and 2 control groups with empty tubes (n = 5/group). At the end of experimental periods (7, 21, and 63 days), the tissue was removed and histotechnically processed. Angioblastic proliferation and edema (Fisher's exact test) were evaluated, besides thickness measurement (μm) of the reactionary granulomatous tissue and neutrophil counts (Kruskal-Wallis and Dunn's post test; Mann-Whitney) (α = 0.05).
MTT assay, trypan blue, and analysis of apoptotic cells showed a dose-dependent direct effect: the more diluted the sealer, the less cytotoxic. Regarding the angioblastic proliferation and edema, difference between the sealers at 7 and 63 days occurred (p < 0.05). Both endodontic sealers initially promoted perimaterial tissue reaction as a foreign body granuloma and thus stimulated favorable tissue responses.
Both sealers showed a dose-dependent effect and promoted satisfactory subcutaneous tissue response; the sealer Sealapex Xpress was less cytotoxic and more biocompatible than RealSeal XT.
The step of root canal filling during endodontic treatment is highly important for the preservation of the periapical tissue integrity. Subcutaneous reaction to endodontic sealers enables scientific basis for clinical use.
本研究旨在评估两种新型根管封闭剂 RealSeal XT1 和 Sealapex Xpress 在小鼠皮下结缔组织中的体外细胞毒性和体内生物相容性。
通过 MTT 测定法（单因素方差分析）、台盼蓝试验（Mann-Whitney）和流式细胞仪检测细胞凋亡来评估细胞毒性。对于皮下研究，将填充有密封剂的聚乙烯管植入 70 只 BALB/c 小鼠中：6 个实验组（n=10/组）和 2 个对照组（n=5/组），每组各有 5 个空管。在实验期结束时（7、21 和 63 天），取出组织并进行组织学处理。评估血管母细胞增殖和水肿（Fisher 确切检验），以及反应性肉芽组织厚度测量（μm）和中性粒细胞计数（Kruskal-Wallis 和 Dunn 事后检验；Mann-Whitney）（α=0.05）。
MTT 测定法、台盼蓝和凋亡细胞分析显示出剂量依赖性直接效应：密封剂稀释度越高，细胞毒性越低。关于血管母细胞增殖和水肿，7 天和 63 天之间的密封剂存在差异（p<0.05）。两种根管封闭剂最初都作为异物肉芽肿促进了周围组织的反应，从而刺激了有利的组织反应。
两种封闭剂均表现出剂量依赖性效应，并促进了令人满意的皮下组织反应；与 RealSeal XT 相比，密封剂 Sealapex Xpress 的细胞毒性更低，生物相容性更好。
根管治疗过程中的根管填充步骤对根尖周组织完整性的保存非常重要。皮下对根管封闭剂的反应为临床应用提供了科学依据。
