Impact of Multispecies Biofilm on the Chemical and Mechanical Characteristics of Radicular Dentin from Diabetic and Non-Diabetic Patients: An in-vitro Study.

Abstract

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 non-diabetic 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/buccolingual). Pentosidine, collagen cross-linking ratio, and mineral-to-collagen ratio were determined by Fourier-transform infrared spectroscopy (FTIR) and fatigue resistance was evaluated by the four-point flexure test to failure 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 strength 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.