Effect of Delayed Endodontic Sealing with Dentin Biomodification on Fracture Resistance of Endodontically Treated Teeth

Aim: Endodontically treated teeth display altered tooth structure pertaining to various chemical irrigants and intracanal medicaments. To prevent the compromised adhesive bond, dentin biomodification is indicated. This study was designed to evaluate the influence of dentin biomodification on the fracture resistance of root canal-treated teeth following Delayed Endodontic Sealing (DES). Materials and Methods: In 50 maxillary central incisors, Class III cavities along with access cavities were prepared. The samples were randomly divided into five groups. Group 1: Intact teeth (N = 10), Group 2: Immediate Endodontic Sealing (IES) (N = 10); Group 3: DES after irrigation with 3% NaOCl (N = 10); Group 4: DES with 2% chlorhexidine (CHX) as a biomodifier (N = 10) and Group 5: DES with 5% grape seed extract (GSE) as a biomodifier (N = 10). In Group 2 samples, composite restorations were done prior to irrigation with 3% sodium hypochlorite (NaOCl). Group 3 samples received root canal irrigation with 3% NaOCl for 1 min, etch and rinse procedure and composite restorations. In Groups 4 and 5, dentin biomodification was done prior to composite restorations. Teeth were subjected to fracture resistance tests. Statistical analysis was carried out employing analysis of variance (ANOVA) and Tukey's post hoc tests (p < .05). Results: IES group demonstrated the highest fracture resistance, with a significant difference statistically (p < .05) when compared with the DES groups. DES modified with GSE resulted in significantly superior fracture resistance compared to DES only, but no statistical difference was present between the CHX and grape seed-treated DES groups. Conclusion: DES with the use of dentin biomodifiers such as 5% GSE and 2% CHX increased the fracture resistance of root canal-treated teeth compared to DES only.