Private practice, Crotone, Italy.
Department of Biomedical, Metabolic and Neural Sciences, Section of Human Morphology, University of Modena and Reggio Emilia, Modena, Italy.
Int Endod J. 2017 May;50(5):492-498. doi: 10.1111/iej.12641. Epub 2016 Apr 17.
The aim of this study was to evaluate ex vivo the penetration depth of sodium hypochlorite solutions, with and without surfactants, into human dentine using a histochemical stain and the bleaching ability of NaOCl.
Extracted maxillary central incisors were decoronated and their root canals were shaped to a size 30, .07 taper. Dentinal tubules were stained with 10% copper sulphate solution followed by a 1% rubeanic acid alcohol solution under vacuum. Specimens were irrigated with 5 mL of Niclor 5 (5.25% NaOCl solution) or 5 mL of Hypoclean (5.25% NaOCl solution + surfactants) according to the corresponding treatment group, for 2 min. A transverse section was obtained in the middle portion of the apical, middle and coronal thirds of each tooth. Under microscopic examination, irrigant penetration was evaluated by measuring the following: the bleached circumference of the root canal with respect to the stained circumference; bleached areas, mean and maximum penetration depth. For statistical analysis, Pearson's chi-squared test and one-way anova were used.
Only 30% of dentine tubules in the apical portions were stained; therefore, these were excluded from further comparisons. In the middle and coronal thirds, the average bleached circumference of the root canal was 80-99% of the stained circumference and the bleached area was 73757-135107 μm . The average penetration depth ranged from 39 to 62 μm and maximum penetration from 74 to 131 μm. For all reported results, no differences within and between groups were observed (P = 1).
No differences in penetration of irrigants with and without surfactants into dentinal tubules were observed in the middle and coronal thirds of incisor teeth.
本研究旨在通过组织化学染色评估含或不含表面活性剂的次氯酸钠溶液进入人牙本质的渗透深度，并评估 NaOCl 的漂白能力。
从上颌中切牙中提取，然后截冠，根管预备至 30 号，0.07 锥度。牙本质小管用 10%硫酸铜溶液染色，然后在真空下用 1%茜素醇溶液染色。根据相应的处理组，用 5 mL 的 Niclor 5（5.25% NaOCl 溶液）或 5 mL 的 Hypoclean（5.25% NaOCl 溶液+表面活性剂）冲洗 2 分钟。在根尖、中 1/3 和冠 1/3 的中间部分获得一个横向切片。在显微镜下，通过测量以下内容评估冲洗液的渗透情况：相对于染色周长的根管漂白周长；漂白面积、平均和最大渗透深度。统计分析采用 Pearson's chi-squared 检验和单因素方差分析。
仅根尖部分的 30%牙本质小管被染色；因此，这些结果被排除在进一步的比较之外。在中 1/3 和冠 1/3，根管的平均漂白周长为染色周长的 80-99%，漂白面积为 73757-135107 μm。平均渗透深度为 39-62 μm，最大渗透深度为 74-131 μm。对于所有报告的结果，组内和组间均未观察到差异（P=1）。
在中切牙的中 1/3 和冠 1/3 中，未观察到含或不含表面活性剂的冲洗液进入牙本质小管的渗透差异。
