Micro-computed Tomography-aided Evaluation for Root Dentin Micro-cracks after Root Canal Instrumentation in Diabetic and Nondiabetic Older Patients: A Pilot In vivo Study.

Context: Dentinal microcracks during root canal preparation with endomotor-driven files suggest adverse consequences, while research results remain inconsistent. Diabetic individuals have modified dentin properties due to advanced glycation end-products (AGEs), altering collagen-rich tissue mechanics. Age-related changes and diabetes reduce mechanical strength and cause progressive dentinal tubule occlusion. Aims: This pilot in vivo study assessed microcrack formation following rotational and reciprocating instrumentation in diabetic versus nondiabetic elderly adults using micro-computed tomography (CT). Settings and Design: Pilot in vivo comparative study design. Subjects and Methods: Twenty-two vital mandibular anterior teeth from patients aged 50-70 years requiring extraction were included. Teeth were categorized into diabetic (n = 9) and nondiabetic (n = 8) groups, instrumented with ProTaper Gold or Reciproc Blue systems. An over-instrumented control group (n = 5) was prepared 3 mm beyond the apex. Following atraumatic extraction, specimens were scanned using micro-CT (7.9 μm resolution) and analyzed for microcracks in coronal, middle, and apical thirds using ImageJ software. Statistical Analysis Used: Frequency and percentages were calculated for microcrack occurrence. Results: Irrespective of the type of instrumentation, no microcracks were observed in diabetic or nondiabetic groups. In the over-instrumented group, 60% of samples (3/5) developed incomplete apical microcracks extending from the canal into root dentin. Conclusions: Root canal instrumentation to apical constriction did not produce microcracks in diabetic or nondiabetic older patients. However, over-instrumentation significantly increased microcrack formation, suggesting adherence to root canal anatomy improves endodontic treatment efficacy.