Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
J Endod. 2011 Aug;37(8):1109-15. doi: 10.1016/j.joen.2011.05.013.
Intracanal disinfection is a crucial step in regenerative endodontic procedures. However, this novel endodontic treatment lacks standardization, and numerous treatment protocols have been reported without knowledge of the effect of disinfection protocols on the survival of stem cells. The aim of this study was to test the hypothesis that different root canal irrigation protocols alter survival of stem cells from the apical papilla (SCAP).
SCAP were isolated from immature human third molars, and a subpopulation of STRO-1 expressing cells was selected and expanded in vitro. Standardized human root segments (n = 5/group) were irrigated with 1 of 4 protocols: (1) 17% ethylenediaminetetraacetic acid (EDTA), (2) 6% NaOCl/17% EDTA/6% NaOCl, (3) 17% EDTA/2% chlorhexidine (CHX), or (4) 6% NaOCl/17% EDTA/6% NaOCl/isopropyl alcohol/2% CHX. Subsequently, STRO-1-enriched SCAP were mixed with platelet-rich-plasma, seeded into the root tips, and cultured for 21 days. Roots were then decalcified, processed for immunohistochemistry, and stained for vimentin and TO-PRO-3. The proportion of viable (vimentin-positive) cells was calculated on the basis of the total cell counts (TO-PRO-3) for each group.
Irrigation with 17% EDTA best supported cell survival (89% viability; P < .001 versus all other groups), followed by irrigation with 6% NaOCl/17% EDTA/6% NaOCl (74%; P < .001 versus the 2 groups containing 2% CHX). Conversely, protocols that included 2% CHX lacked any viable cells.
Collectively, the results suggest that irrigants alone greatly affect the survivability of STRO-1-enriched SCAP within the root canal environment and that inclusion of EDTA in irrigation protocols might be beneficial in regenerative procedures.
在再生性牙髓治疗过程中，根管内消毒是一个关键步骤。然而，这种新型的牙髓治疗缺乏标准化，并且有许多治疗方案被报道，但却不知道消毒方案对干细胞存活的影响。本研究旨在验证以下假设，即不同的根管冲洗方案会改变根尖乳头干细胞（SCAP）的存活。
从未成熟的人第三磨牙中分离出 SCAP，并在体外选择和扩增 STRO-1 表达细胞的亚群。将标准化的人牙根段（n = 5/组）用 4 种方案中的 1 种冲洗：（1）17%乙二胺四乙酸（EDTA）；（2）6%次氯酸钠/17% EDTA/6%次氯酸钠；（3）17% EDTA/2%洗必泰（CHX）；或（4）6%次氯酸钠/17% EDTA/6%次氯酸钠/异丙醇/2% CHX。随后，将富含 STRO-1 的 SCAP 与富含血小板的血浆混合，接种到根尖，培养 21 天。然后对牙根进行脱钙、免疫组织化学处理，并对波形蛋白和 TO-PRO-3 进行染色。根据每组的总细胞计数（TO-PRO-3）计算存活（波形蛋白阳性）细胞的比例。
用 17% EDTA 冲洗最能支持细胞存活（89%存活率；P <.001 与所有其他组相比），其次是用 6%次氯酸钠/17% EDTA/6%次氯酸钠冲洗（74%；P <.001 与含有 2% CHX 的 2 组相比）。相反，含有 2% CHX 的方案则没有任何存活的细胞。
总的来说，结果表明，冲洗剂本身会极大地影响根管内环境中富含 STRO-1 的 SCAP 的存活率，并且在冲洗方案中加入 EDTA 可能对再生性治疗有益。
