A Novel Dentin Push-out Bond Strength Model That Uses Micro-Computed Tomography

Area of Science:

• Endodontics
• Dental Materials Science
• Biomaterials Engineering

Background:

• Current push-out experimental methods in endodontic research require enhancement.
• A novel dentin push-out bond strength model utilizing micro-computed tomography (μCT) was developed.

Purpose of the Study:

• To introduce and validate a new micromechanical model for assessing the push-out bond strength of endodontic root fillings.
• To correlate bond strength with interfacial gaps using advanced imaging techniques.

Main Methods:

• Roots filled with gutta-percha and resin sealers were sectioned, and slices underwent push-out tests within a μCT scanner.
• μCT scans before and after testing evaluated filling material ruptures; 3D finite element analysis models were generated.
• Confocal laser scanning microscopy assessed failure modes and interfacial gaps; bond strength and gap data were statistically analyzed.

Main Results:

• The μCT-based push-out model demonstrated consistent results with coefficients of variation below 30%.
• Finite element analysis effectively explained bond strength variations and root-filling ruptures.
• A significant, moderate, indirect correlation was found between bond strength and interfacial gaps.

Conclusions:

• The developed micromechanical model using μCT images offers a reliable method for evaluating root-filling bond strength.
• This novel approach enhances the accuracy and consistency of push-out bond strength testing in endodontics.