Department of Endodontics, Universidad Europea de Madrid, Madrid, Spain.
Int Endod J. 2012 May;45(5):475-81. doi: 10.1111/j.1365-2591.2011.01999.x. Epub 2012 Jan 27.
To assess the ability of sodium hypochlorite (NaOCl) to penetrate simulated lateral canals and to reach working length (WL) when using the self-adjusting file (SAF).
Seventy single-rooted teeth with oval-shaped canals were used. Upon access, presence of a single canal was confirmed by direct visualization under a dental-operating microscope. Canal length and patency were obtained using a size 10 K-file and root length standardized to 18 mm. Pre-enlargement was restricted to the coronal one-third. The apical size of each canal was gauged at WL and samples larger than size 30 were excluded. Canals were instrumented for 5 min using the SAF system while delivering a total of 20 mL of 5.25% NaOCl and 5 mL of 17% EDTA. Then, the apical diameters were standardized to size 35 using hand files. Four hundred and twenty simulated lateral canals were then created during the clearing process and roots coated with wax to create a closed system. All samples were then cleared and randomly assigned to four experimental groups: 1 (n = 15) positive pressure; 2 (n = 15) SAF without pecking motion; 3 (n = 15) SAF with pecking motion; 4 (n = 15) apical negative pressure (ANP) irrigation and (n = 10) control groups. Samples were scored on the basis of the ability of the contrast solution to reach WL and permeate into the simulated lateral canals to at least 50% of the total length. The Kruskal-Wallis test was used to analyse irrigant penetration and the Tukey test to determine statistical differences between groups (P < 0.05).
All samples irrigated with ANP were associated with irrigant penetration to WL (Table 1). The differences between group 4 (ANP) and all other groups were significant in penetration to WL (P < 0.05). The pecking motion allowed for further penetration of the irrigant when using the SAF system but failed to irrigate at WL. None of the experimental groups demonstrated predictable irrigation of simulated lateral canals.
In this laboratory model, ANP was the only delivery system capable of irrigating consistently to full WL. None of the systems tested produced complete irrigation in artificial lateral canals.
评估次氯酸钠（NaOCl）在使用自调整锉（SAF）时穿透模拟侧支根管并到达工作长度（WL）的能力。
本研究共使用 70 颗具有椭圆形根管的单根牙。在进入根管时，通过在牙科手术显微镜下直接观察来确认只有一个根管。使用 10 K 锉确定根管长度和通畅度，并将根长标准化为 18mm。预扩仅限于根管的冠部 1/3。在 WL 处测量每个根管的根尖尺寸，排除大于 30 号的样本。使用 SAF 系统对根管进行 5 分钟的锉锉，同时输送 20 毫升 5.25%次氯酸钠和 5 毫升 17% EDTA。然后，使用手动锉将根尖直径标准化至 35 号。在清理过程中，然后创建 420 个模拟侧支根管，并在根管上涂蜡以形成封闭系统。所有样本均经过清理，并随机分为四组进行实验：1 组（n=15）正压；2 组（n=15）无啄动 SAF；3 组（n=15）啄动 SAF；4 组（n=15）根尖负压（ANP）冲洗，（n=10）对照组。根据对比溶液到达 WL 的能力以及渗透到模拟侧支根管至少 50%总长度的能力对样本进行评分。使用 Kruskal-Wallis 检验分析冲洗剂的渗透情况，并用 Tukey 检验确定组间的统计学差异（P<0.05）。
所有使用 ANP 冲洗的样本均与 WL 处的冲洗剂渗透相关（表 1）。组 4（ANP）与其他所有组在 WL 处的渗透差异均有统计学意义（P<0.05）。啄动运动允许 SAF 系统进一步渗透冲洗剂，但未能在 WL 处冲洗。在所有实验组中，均未观察到对模拟侧支根管的可预测冲洗。
在本实验室模型中，ANP 是唯一能够持续冲洗至完全 WL 的输送系统。在测试的系统中，没有一个系统能在人工侧支根管中完全冲洗。
