Pramodh N R, Kumar C N Vijay, Pradeep M R, Naik Ravi, Mahesh C S, Kumari Manju R
Department of Prosthodontics, Subbaiah Institute of Dental Sciences, Shimoga, Karnataka, India.
Department of Conservative and Endodontics, Subbaiah Institute of Dental Sciences, Shimoga, Karnataka, India, e-mail:
J Contemp Dent Pract. 2017 Dec 1;18(12):1185-1189. doi: 10.5005/jp-journals-10024-2197.
The aim of this study was to evaluate the tensile strength of die stone incorporated with sodium and calcium hypochlorite as disinfectants.
Two commercially available type IV die stone (Kalrock: Kalabhai Karson Pvt., Ltd and Pearlstone: Asian Chemicals) and two commercially available disinfectant solutions (sodium hypochlorite and calcium hypochlorite: Beachem Laboratory Chemical Private Limited, Chennai and Leo Chem Private Limited, Bengaluru) were used in this study, and the tensile strength was measured using Lloyd's Universal Testing Machine.
The results show that incorporating the disinfecting solutions decreases the tensile strength of both products. The effect of decreasing tensile strength on type IV gypsum product is seen more in calcium hypochlorite when compared with sodium hypochlorite disinfecting solution, and the tensile strength of Kalrock specimens is higher than Pearlstone specimens after disinfecting with sodium hypochlorite and calcium hypochlorite solution. The statistical results also show significant results in all the groups when compared with the control group.
The incorporation of sodium and calcium hypochlorite disinfecting solutions is not an encouraging method for both die materials as it reduces the tensile strength of type IV gypsum product. Tensile strength of Kalstone® die material is superior than Pearlstone® die material after mixing with sodium hypochlorite and calcium hypochlorite.
According to the recommendations of Americans with Disability Act (ADA) and the Centers for Disease Control and Prevention, disinfecting the whole cast without or minimal changes in physical and mechanical properties was the motto of the study. The tensile strength in type IV gypsum product plays a most important role in retrieval of cast from impression, especially in narrow tooth preparation. This study reveals that incorporating method of disinfecting solutions is not recommended as it reduces the tensile strength.
本研究旨在评估添加次氯酸钠和次氯酸钙作为消毒剂的模型石膏的拉伸强度。
本研究使用了两种市售的IV型模型石膏（Kalrock：Kalabhai Karson私人有限公司；Pearlstone：亚洲化学公司）和两种市售的消毒溶液（次氯酸钠和次氯酸钙：分别来自钦奈的Beachem实验室化学私人有限公司和班加罗尔的Leo Chem私人有限公司），并使用劳埃德万能材料试验机测量拉伸强度。
结果表明，添加消毒溶液会降低两种产品的拉伸强度。与次氯酸钠消毒溶液相比，添加次氯酸钙时IV型石膏产品的拉伸强度降低更为明显，并且用次氯酸钠和次氯酸钙溶液消毒后，Kalrock标本的拉伸强度高于Pearlstone标本。统计结果还显示，与对照组相比，所有组均有显著差异。
对于这两种模型材料而言，添加次氯酸钠和次氯酸钙消毒溶液并非理想方法，因为它会降低IV型石膏产品的拉伸强度。与次氯酸钠和次氯酸钙混合后，Kalstone®模型材料的拉伸强度优于Pearlstone®模型材料。
根据美国《残疾人法案》（ADA）和疾病控制与预防中心的建议，在不改变或最小化改变物理和机械性能的情况下对整个铸型进行消毒是本研究的主旨。IV型石膏产品的拉伸强度在从印模中取出铸型时起着至关重要的作用，尤其是在窄牙制备中。本研究表明，不建议采用添加消毒溶液的消毒方法，因为它会降低拉伸强度。
