Impact of Multispecies Biofilm on the Chemical and Mechanical Characteristics of Radicular Dentin from Patients With and Without Diabetes: An In Vitro Study

Introduction

This in vitro study examined the effect of a multispecies biofilm on the chemical characteristics and mechanical properties of root dentin from patients with or without type 2 diabetes mellitus (DM).

Methods

Intact mandibular molars were obtained from diabetic and nondiabetic donors. Rectangular root dentin beams were prepared and categorized based on age (40–60 and 61–80 years), presence/absence of DM, and the site of dentin beam extraction (mesiodistal or buccolingual). Pentosidine, collagen cross-linking ratio, and mineral-to-collagen ratio were determined by Fourier transform infrared spectroscopy and fatigue resistance was evaluated by the four-point flexure to failure test with or without exposure to a multispecies biofilm for 21 days.

Results

DM and biofilm exposure significantly increased pentosidine, mineral-to-collagen ratio, and collagen cross-linking ratio in root dentin from both age groups (P < .05). Control root dentin from the 61–80 years group had significantly lower fatigue resistance than root dentin from the 40–60 years group (P < .05). DM reduced the fatigue resistance of root dentin but not significantly (P > .05). After biofilm exposure, root dentin with DM had significantly lower fatigue resistance than root dentin without DM (P < .05). Biofilm exposure significantly reduced the fatigue resistance of root dentin with or without DM when compared with the controls only in the 40–60 years group (P < .05).

Conclusions

Aging decreased the fatigue resistance of root dentin. DM and biofilm exposure increased pentosidine, mineral-to-collagen ratio, and collagen cross-linking in root dentin across both age groups. Biofilm exposure further reduced the fatigue resistance of root dentin with DM compared to root dentin without DM.