Effect of handpiece light and material used in pulp chamber on dentin removal during root canal retreatment

Abstract

This study evaluated the effect of the use of glass ionomer cement (GIC) and flowable bulk-fill resin composite (BFRC) for filling pulp chambers and the type of high-speed handpiece light used on dentin removal during access preparation for endodontic retreatment in molar teeth. Twenty maxillary molars were treated endodontically. BFRC (Opus Bulk Fill Flow APS, FGM) was used to fill the pulp chamber and replace coronal dentin (n = 10). In the remaining teeth, the pulp chamber was filled with GIC (Maxion R, FGM). Conventional resin composite (Opallis, FGM) was used to restore the enamel layer in all teeth. The samples in each group were divided into two subgroups, and the root canals were reaccessed using a handpiece with white or ultraviolet light. The teeth were scanned using micro-CT before and after root canal reaccess. The dentin volume removed was calculated and analyzed using 2-way analysis of variance and Tukey’s test (α = 0.05). The crown and pulp chamber locations with dentin removal are described using frequency distribution. During the access, fewer pulp chamber walls were affected and a lower volume of dentin was removed from the pulpal floor in the group restored with GIC than in the group restored with BFRC. No effect was observed on the coronal dentin walls with respect to the filling protocols and type of light used. For dentin removal from the pulp chamber, handpieces with white light performed better than those with ultraviolet light, irrespective of the filling protocol used. The use of GIC to fill the pulp chamber and use of white handpiece light reduced dentin removal from the pulpal floor and resulted in fewer affected dentin walls.

Fluorescence intensity of composite resin for direct veneer removal using a fluorescence‐aided identification technique

“…A high-speed handpiece emitting ultraviolet (UV) light at an intensity of 350-400 nm can be used for this technique. 4,17,18 Nevertheless, for this technique to be effective, the use of fluorescent resins is essential. 13 Currently, composite resins have different fluorescence intensities (high, medium, and low).…”

“…In this context, the fluorescence‐aided identification technique (FIT) may be effective for stimulating fluorescent particles present in composite resin to facilitate their visualization and removal. A high‐speed handpiece emitting ultraviolet (UV) light at an intensity of 350–400 nm can be used for this technique 4,17,18 …”