The Influence of Minimally Invasive Access Cavities on the Cleaning Ability of Primary Infected Root Canals: An in-Vitro Study

Abstract

Introduction: An endodontic treatment’s success is contingent upon appropriate shaping, cleaning, as well as effective disinfection followed by obturation, which seals the complex anatomy completely. For the purpose of maintaining the maximum volume of dentin, a novel endodontic access cavity concept has been recently gained popularity. The preservation of the most important peri-cervical dentin is the primary focus of this types of coronal access. In contrast to traditional endodontic access cavity preparation (TEAC), conservative endodontic cavity (CEC) preparation is a minimally invasive procedure that can preserve tooth structures, such as pericervical dentin. Therefore, the current study might be of value. Aim: the current study was carried out to evaluate the influence of minimally invasive endodontic access cavities (truss, pointed) versus conventional ones on cleaning ability of primary infected root canals. Materials and Methods: the research was approved by Research Ethical Committee (REC) of the Faculty of Dentistry Suez Canal University, with appoval no. #201/2019. This study was carried on 36 intact freshly extracted human mandibular first molars. The selected teeth were initially infected with Fusobacterium nucleatum (ATCC 10953), and Streptococcus Intermedius (ATCC 27335) then were randomly allocated into three equal groups (n=12) based on the type of access cavity: Group (A0): the selected teeth will receive conventional access cavities, Group (A1): the selected teeth will receive truss access cavities, and Group (A2): the selected teeth will receive pointed access cavities. Biomechanical preparation was performed using TruNatomy and irrigated with NaOCl 2.5% + EDTA 17% and ChloraEXtra + EDTA 17%. Confocal Laser Scanning was performed. All records were collected, tabulated and statistically analyzed to evaluate the influence of minimally invasive endodontic access cavities versus conventional ones on cleaning ability of primary infected root canals. Results: The findings revealed that Conservative access with ChloroExtra irrigation had the statistically significantly lowest mean Bacterial Percentage reduction. While Conventional access cavity either using NaOCl or ChloroExtra irrigation showed the highest bacterial reduction, followed by Truss access cavity with NaOCl, Truss access cavity with ChloroExtra, and Conservative access cavity with NaOCl respectively, with no significant difference. Using ChloroExtra irrigation negatively affected the bacterial reduction in each group, regardless of the type of access used, with the least bacterial reduction in the conservative access design group. While NaOCl irrigation increased the bacterial reduction within each group, with comparable results among all groups. Conclusion: 1. Using both NaOCl and ChloroExtra lead to reduction in bacterial count. 2. Conventional endodontic access cavities are still considered the gold standard in root canal treatment. 3. In terms of bacteria reduction and cleaning capabilities, minimal endodontic access cavities did not outperform conventional endodontic access, truss endodontic access cavity can achieve equivalent outcomes to standard endodontic access cavities. 4. Sodium hypochlorite irrigation is more effective in microbial reduction regardless of endodontic access cavity design used in comparison to ChloroExtra.