Micro-CT evaluation of root canal preparation with rotary instrumentation on prototyped primary incisors

Abstract

This study aimed to evaluate the endodontic instrumentation outcomes with asymmetrical files compared to reciprocating and hand files (HFs) in 3D-printed prototypes of upper primary incisors using micro-computed tomography (micro-CT). For this purpose, 50 prototypes were randomly divided (n = 10) according to the instrumentation technique as follows: HFs, a reciprocating file (WaveOne ® Gold [WOG]), and three asymmetrical movement files: XP-Endo ® Shaper (XPS), XP-Endo ® Finisher (XPF), and XP Clean (XPC). The specimens were scanned and, after registration of the baseline and instrumented volumes, changes in the root canal volume (RCV), debris accumulation, removed root material volume (RRMV), non-instrumented areas, and the presence of cracks/perforations were quantified. Data were analyzed by analysis of variance and Student's t-test, while the effect size was calculated for statistically significant outcomes. All groups showed an increase in RCV after instrumentation (p < 0.05), but this was higher with HFs (p < 0.05). Accumulated debris was higher for WOG and XPS (p < 0.05), but WOG exhibited more in the medium and apical third areas. HFs showed the highest RRMV (p < 0.05), especially at the apical third. The non-instrumented areas were lower for HFs and XPC than for the other systems (p < 0.05). Cracks were present in a few WOG (n = 2) and HF specimens (n = 3) and in this group, one of the cracked specimens and two others showed perforations. The asymmetric systems resulted in conservative dentin removal and fewer cracks/perforations as compared to HFs and a reciprocation file in prototyped primary upper incisors. XPC showed the best compromise between RRMV and non-instrumented areas with a low accumulation of debris.

Update in the Diagnosis and Treatment of Root Canal Therapy in Temporary Dentition through Different Rotatory Systems: A Systematic Review

“…Regarding the sample included in the studies obtained ( Table 1 and Table 2 ), most of them analyzed an average of 30 teeth [ 10 , 11 ]. Highlighting Mohammadi, D [ 12 ], with a maximum of 80, and Moraes [ 13 ] with a minimum of 1. Regarding the variables analyzed, and considering the length of the files, the longest were those used by Gekelman [ 14 ], with a length 25 mm, and the shortest, 15 mm, used by Mohammadi [ 12 ].…”

“…Lastly, regarding the irrigant used, sodium hypochlorite is the most used at different concentrations: 2.5% [ 10 ], 5.25% [ 11 ] or 1% [ 11 ], although other authors also use saline solution to eliminate bacteria [ 13 , 18 ].…”

Instrumentation time and effectiveness of hand and rotary files in a prototyped second mandibular primary molar: A micro‐CT study

“…The latter is a finishing single-file system that has been suggested as an effective and yet conservative approach in the instrumentation of primary teeth. 12 In addition, it has been also shown that full sequence rotary instruments dedicated to primary teeth (Kedo) result in less debris extrusion than non-dedicated systems. 30 In the present study, K-files and XPS instrumentation resulted in more hard tissue debris accumulation inside the root canal.…”

“…In general, most studies corroborate the results herein, in which rotary systems achieve similar or better results than manual files in terms of shaping ability and mechanical instrumentation time in primary molars. 4,6,12,24,[31][32][33][34][35] Canal transportation corresponds to the deviation observed after instrumentation, compared with the initial sound canal, being generally evaluated in mesial roots of permanent mandibular molars. 36 Mesial roots are interesting due to its complex canal morphology and because it closely matches the internal and external morphology of the primary mandibular second molar.…”

“…11 Finally, XP-Clean (XPC-MK Life, Porto Alegre, Brazil) is an eccentric single-file instrument designed to clean root canals, without removing dentin tissue, and has recently been proposed as a conservative and simple approach for endodontic instrumentation in primary teeth. 12 Although the described eccentric instruments have been originally proposed for permanent teeth, there could be a clear potential for the application of these instruments in primary teeth. In this case, endodontic instrumentation is more focused in cleaning or touching root canal walls than in producing a particular shape for obturation.…”