Development of a new in vitro methodology to simulate internal root resorption

Area of Science:

• Endodontics
• Dental Imaging
• Biomaterials

Background:

• Current methods for simulating internal root resorption (IRR) using burs create artificial lesions.
• These standardized lesions do not accurately reflect physiological root resorption, potentially masking the true diagnostic accuracy of imaging techniques.

Purpose of the Study:

• To develop and evaluate a novel methodology for simulating internal root resorption using acid demineralization.
• To create more biologically relevant models of IRR for improved diagnostic imaging research.

Main Methods:

• Extracted single-rooted teeth were sectioned, and root canals were prepared for controlled fluid action.
• A protocol involving cycles of nitric acid and sodium hypochlorite was used to induce demineralization.
• Lesion area and depth were quantified using electron microscopy imaging.

Main Results:

• The acid demineralization protocol successfully simulated internal root resorption lesions of varying sizes.
• Measured lesion areas ranged from 3.14 mm² to 10.34 mm², with depths from 0.22 mm to 1.59 mm.

Conclusions:

• The simulated lesions exhibited irregular shapes and a larger diameter:depth ratio, closely resembling in vivo internal root resorption.
• This acid demineralization technique offers a more accurate model for studying IRR compared to bur-induced methods.