Digital image analysis method to assess the performance of conventional and self-limiting concepts in dentine caries removal

Abstract

Objective: To assess dentine caries removal effectiveness (CRE) and minimal invasiveness potential (MIP) of carbide and polymer burs.

Methods: Sectioned carious molars were photographed. Digital images were taken, before and after caries removal, using a Digital Single Lens Reflex camera. The following regions of interest were measured using visual criteria: Residual Infected Dentine (RI), Residual Affected Dentine (RA), Removal Sound Dentine (RA), Prepared Cavity (PC) and Removed Sound Dentine (RS). CRE was determined on basis of: relative residual infected dentine (RI/II), relative residual carious-affected dentine (RA/IA) and total relative residual dentine (RI+RA/II-IA). MIP was determined on basis of: infected dentine cavity size (PC/II), total relative cavity size (PC/II+IA), and corrected relative cavity size (PC-RS/II+IA).

Results: The polymer bur showed the highest preservation of carious-affected dentine after excavation, when the RA/IA ratio was studied. Both kind of burs showed similar values after assessing the RI/II and RI+RA/II-IA ratios. The infected dentine relative cavity size (PC/II) was higher when the carbide bur was used. Both burs attained similar PC/II+IA and PC-RS/II+IA ratios.

Conclusions: Polymer burs accomplished the concept of minimal-invasive dentistry, showing its self-limiting ability. The minimal-invasiveness potential showed that carbide burs resulted in the worst compromise between effective and selective infected-caries removal.

Keywords: Affected; Bur; Carbide; Caries; Dentine; Digital; Excavation; Infected; Polymer.