Push-out bond strength of bioactive repair materials exposed to endodontic irrigants

Aim: This study aimed to evaluate the push-out bond strength (PBS) of three endodontic repair materials (ProRoot MTA, NeoPutty, and Endocem MTA Premixed) to root dentin, assess the impact of different irrigation solutions on PBS, and classify the post-testing failure modes. Material and Methods: A total of 180 root slices were randomly divided into three groups based on the repair material (n=60). After repair materials were inserted, the samples were randomly subdivided into four subgroups (n=15) based on the irrigation solution exposure: saline, sodium hypochlorite (NaOCl), ethylenediaminetetraacetic acid (EDTA), and unexposed. An Instron Universal Testing Machine measured the PBS of the three study materials, and failure modes post-PBS testing were identified using a stereomicroscope. Results: PBS assessments revealed that ProRoot MTA and Endocem MTA Premixed exhibited significantly superior bond strengths compared to NeoPutty. Irrigation with saline reduced the PBS of ProRoot MTA relative to NaOCl and the control group. In contrast, NaOCl irrigation significantly diminished the PBS of NeoPutty when compared to control group, saline, and EDTA. All three solutions did not affect the PBS of Endocem MTA Premixed. Failure mode analysis indicated a predominance of cohesive failure in ProRoot MTA (71.7%) and Endocem MTA Premixed (66.7%), whereas NeoPutty mainly showed mixed failure (65%). Discussion: The results of the present study indicate that Endocem MTA Premixed presents a robust bioactive cement alternative for perforation repair, withstanding various irrigation solutions.