Comparison of access cavities prepared using the guided endodontc technique and conventional access in teeth with different levels of root canal calcification

Aim: The aim of this study was to compare guided endodontic cavity and conventional endodontic cavity preparation in three-dimensional printed maxillary central incisors with different levels of root canal calcification in terms of substance loss and duration of treatment. Material and Method: 72 maxillary incisors were printed in three dimensions to simulate root canal calcification at different levels. The block was divided into 6 groups (n=12) by randomization, namely guided endodontic cavity and conventional endodontic cavity. The guide template for guided endodontic cavity preparation was designed and produced in a special software program from cone beam computed tomography data and intraoral scan data. Substance loss was calculated from the volume difference between the cone beam computed tomography scan data before and after treatment and the duration of treatment was also recorded. Statistical analyses were performed using IBM SPSS Statistics 29.0.2.0 (SPSS Inc., Chicago, IL, USA). The Kolmogorov–Smirnov Test was applied to determine whether the data were normally distributed. Variance equality was assessed using Levene's Test. When assumptions were met, an independent samples t-test was applied for pairwise comparisons between techniques. The Mann–Whitney U test was used for time comparisons in non-normally distributed groups. In all statistical evaluations, p<0.05 was considered significant. Results: Significantly less volume loss was seen in the guided endodontic cavity compared to the conventional endodontic cavity at all levels of calcification (p<0.001). The duration of treatment was significantly shorter in the guided endodontics groups at 16 and 20 mm (p<0.001), and there was no significant difference between the groups at the 12 mm level (p=0.355). Both methods significantly higher volume loss at the 20 mm level than at 12 mm (p≤0.001). The treatment time was significantly shorter at the 12 mm level compared to 16 and 20 mm in the traditional cavity technique (p≤0.004). In the guided cavity, there is only a difference of 12 mm to 20 mm (p=0.004). Conclusions: Guided access significantly reduces substance loss in calcified canals and, at 16–20 mm calcification, shortens procedure time, supporting its role as a tissue-sparing, efficient alternative to conventional access.