Objective: This study was undertaken to compare microhardness and erosion susceptibility of root dentine in teeth extracted from diabetic and non-diabetic donors after the application of different root canal irrigants.
Methods: Forty-eight single-rooted premolars with single canals (24 each from diabetic and non-diabetic) were selected, and root canals were shaped by using rotary ProTaper files. Dentine slices of 4 mm were transversely sectioned from the middle root third. Specimens were assigned to four subgroups (n=6) and irrigated for 5 minutes: 1) 2.6% sodium hypochlorite (NaOCl); 2) 17% ethylenediaminetetraacetic acid (EDTA); 3) 2% chlorhexidine (CHX); and 4) normal saline. Surface microhardness was determined at 100- and 500-µm depths from the pulp-dentine interface. Scanning electron microscope (SEM) was used to determine the severity of dentine erosion. Data were analyzed by using two-way ANOVA, Post-hoc Tukey's, and Chi-square tests (P<0.05).
Results: Diabetes as well as NaOCl and EDTA decreased surface microhardness of dentine significantly (P<0.05). Diabetes had little effect on the erosion susceptibility of dentine (P>0.05).
Conclusion: Root canal irrigants can significantly lower the microhardness; specifically, in diabetic patients, and may be a factor affecting the longevity of root canal-treated teeth.