Apical sealing and resistance strength of C-Root BP material in in vitro environment

Abstract

BACKGROUND: In recent years, bioceramic materials have become the preferred materials for retrograde apical filling due to their excellent biocompatibility and sealing properties. The bioceramic materials C-Root BP and iRoot BP Plus both exhibit excellent biocompatibility and sealing properties. OBJECTIVE: To compare the apical sealing performance and resistance strength of C-Root BP and iRoot BP Plus materials in vitro. METHODS: From June 2022 to June 2024, 56 freshly extracted single detached teeth at the Department of Stomatology, Shijiazhuang Second Hospital due to orthodontics or periodontal disease were collected and randomly divided into four groups. The iRoot BP Plus group (n=16) and C-Root BP group (n=16) were respectively treated with iRoot BP Plus and C-Root BP materials for root tip filling. The positive control group (n=16) was treated with distilled water for root tip filling, while the negative control group (n=8) was not treated with root tip filling and only underwent routine root canal preparation and disinfection. Dye penetration method was used to detect apical sealing; bacterial microleakage was evaluated using an in vitro model; push-out test was used to measure the bond strength between filling material and dentin, and fracture patterns were observed under microscope. RESULTS AND CONCLUSION: After 7 days of dye staining, the dye penetration length in the positive control group was greater than that in the iRoot BP Plus and C-Root BP groups (P < 0.05), with no significant difference between the iRoot BP Plus and C-Root BP groups (P > 0.05). After 90 days of culture, the incidence of bacterial microleakage in the positive control group was higher than that in the iRoot BP Plus and C-Root BP groups (P < 0.05), with no significant difference between the iRoot BP Plus and C-Root BP groups (P > 0.05). The bond strength between filling material and dentin in the C-Root BP group was greater than that in the iRoot BP Plus group (P < 0.05), and there was no significant difference in fracture patterns between the two groups (P > 0.05). These results indicate that C-Root BP and iRoot BP Plus materials can produce similar apical sealing effects and fracture patterns, but C-Root BP material has better bond strength.

1. Introduction

Periapical disease is a common infectious condition in dentistry that severely affects patients' oral health and quality of life [1]. Retrograde apical filling is an important treatment modality for periapical disease, which involves resection of periapical lesions and filling of the root end to prevent intracanal infection from reaching periapical tissues, thereby promoting healing [2-3]. However, traditional retrograde filling materials often exhibit poor apical sealing, leading to microleakage and reduced treatment efficacy [4-5]. Therefore, the development and application of novel retrograde filling materials have become a research hotspot in dentistry.

C-Root BP and iRoot BP Plus are bioceramic-based retrograde filling materials that have gained increasing clinical use. C-Root BP is a bioceramic repair material containing strontium silicate, suitable for complex periapical conditions such as cysts and granulomas, effectively eliminating tissue and promoting bone repair [6-8]. iRoot BP Plus is a calcium silicate-based bioceramic with good sealing, biocompatibility, and bioactivity, and is relatively easy to handle [9-10]. However, comparative studies on C-Root BP and iRoot BP Plus in retrograde filling are still limited, and the differences in apical sealing, resistance strength, and bacterial microleakage remain unclear. This study aims to compare the apical sealing performance and resistance strength of C-Root BP and iRoot BP Plus in vitro, providing evidence for clinical application.