Influence of activation of irrigation on effectiveness of calcium hydroxide removal from the root canal. An in vitro study

Abstract

Our study was conducted to evaluate the effectiveness of ultrasonic in comparison to sonic aided removal of calcium hydroxide interim medication from the root canal system.

The total number of sample was forty-eight straight single rooted teeth. The teeth were randomly divided into two groups according to the type of calcium hydroxide medication used group I using Metapaste group II using pure calcium hydroxide powder mixed with distilled water. Then each group subdivided into two subgroups: subgroup A calcium hydroxide removal was aided by Irrisafe ultrasonic tip subgroup B calcium hydroxide removal was aided by Eddy sonic tip subgroup C passive irrigation with beveled needle.

Crown of the teeth were left to simulate clinical condition. Teeth were instrumented with Protaper NiTi Rotary system up to size F4, then final irrigation protocol as follow: 2.5% NaOCl followed by 17% EDTA and finally distilled water. Metapaste was injected into the teeth, and the pure calcium hydroxide mixed with distilled water was placed with lentulo spiral. The specimens the sealed with temporary filling and stored in incubator at 37°c and 100% humidity for 1 week.

After calcium hydroxide removal teeth were split longitudinally and imaged by stereomicroscope then images analyzed with Image J software to measure the percentage of the remaining calcium hydroxide in each tooth segment (coronal, middle, apical). The samples filled with calcium hydroxide custom made paste showed less remnants than Metapaste filled samples with significant difference. The highest amount of calcium hydroxide remnants was with passive irrigation with significance difference. Eddy sonic irrigation left fewer remnants than Irrisafe ultrasonic irrigation with no significant difference between them. Remnants of calcium hydroxide were left in apical and coronal section more than the middle section with significant difference.