The effects of caries removal techniques on volume-loss percentage and microtensile bond strength

Abstract

Purpose This study aimed to calculate the volume loss percentages (VLP) regarding the ICDAS II system and various caries removal techniques (CRT) and to assess the microtensile bond strength (µTBS) in terms of VLP following CRT. Materials and Methods Three-dimensional data of human extracted molars were acquired with an extraoral dental scanner (Ineos x5, Dentsply Sirona) before and after the caries removal. Each ICDAS score group (0,3,4 and 5) was divided into four subgroups according to the CRT: stainless steel bur (Group S), ceramic bur (Group C), tungsten carbide bur (TCB) and air abrasion (AA) with bioactive-glass (Group TB), and TCB and AA with Al2O3 (Group TA). Pre and post-caries removal data were overlaid in a 3D modeling software and were volumetrically measured (n=10). Following the restoration, samples were prepared with non-trimming technique and subjected to microtensile testing. Results ICDAS II scores were found related the VLP (p< 0.001) and the µTBS (p<0.001). CRT was not effective on VLP (p=0.110), whereas CRT type was significant on µTBS (p<0.001). In Group TA, a strong negative correlation was observed between the µTBS and the VLP for ICDAS 5 score (r=-0.919; p=0.027). Conclusion ICDAS II can provide a preliminary indication for the amount of VLP and reduction in µTBS following caries removal. The use of 29 µm Al2O3 with air abrasion in deep caries removal may improve µTBS while potentially reducing the VLP.