Diabetes Increases Residual Stress and Microcrack Length in Dentin: An XRD-SEM Study with AI-assisted Quantification

Area of Science:

• Biomaterials Science
• Dental Research
• Materials Science

Background:

• Residual stress in root dentin is a critical factor influencing its mechanical integrity.
• Microcracks in dentin can compromise tooth structure and lead to failure.
• Diabetic patients may exhibit altered dentin properties, potentially affecting mechanical responses.

Purpose of the Study:

• To evaluate the association between residual stress and microcrack length in root dentin.
• To compare these parameters in diabetic patients versus healthy controls.
• To utilize an AI-assisted workflow for quantitative analysis.

Main Methods:

• Twenty mandibular premolars (10 diabetic, 10 healthy) were instrumented and sectioned.
• Residual stress was measured using sin²ψ X-ray diffraction.
• Microcracks were analyzed using scanning electron microscopy and an AI-assisted Fiji workflow.

Main Results:

• Diabetic dentin showed significantly higher residual stress (1.40 MPa) compared to controls (-1.10 MPa).
• Microcrack length was substantially greater in diabetic dentin (54.6 μm) than in controls (20.0 μm).
• A positive correlation was found between residual stress levels and microcrack length.

Conclusions:

• Residual stress is a significant contributor to increased microcrack length in instrumented root dentin.
• Diabetic dentin exhibits longer microcracks, suggesting a higher susceptibility to failure.
• These findings may elucidate the increased risk of root fracture in diabetic patients.