Cone-beam dental computerize tomography (CBCT), a noninvasive imaging method, was used to image the pulp-dentin complex. Pulp changes histologically with aging. While many studies have investigated the histological changes in pulp, few studies have focused on the changes in the shape of the root canals. This study evaluated the changes in the root canals with aging of central superior teeth using CBCT. The study examined 100 non-carious maxillary central teeth. These teeth were divided into five groups according to the age of the patients: Group A:15-24, Group B: 25-34, Group C: 35-44, Group D: 45-54 and Group E: 55 years and older. CBCT was used to determine root length, and pulp width at the cervical, apical 1/2, and apical 1/3. On comparing the groups using one-way analysis of variance (ANOVA), the root length did not differ (P>0.05), while the pulp width at the cervical, apical 1/2, and apical 1/3 differed between the groups (P<0.001). The pulp length did not change with aging, while the pulp width did change. CBCT can be used to determine the precise root length and width, to prevent iatrogenic exposure of the apex, complementing existing methods. This will improve the prediction of the prognosis of root canal treatment.

Background:Endodontically treated teeth with excessive loss of tooth structure are frequently restored using fiber posts. In this in vitro study, the apical leakage of self- and dual-activated curing modes for dual-curing resins cementing a transluce...

Aim: The amount of root dentin erosion caused by Ethylene diamine tetraacetic acid (EDTA), Glycolic acid (GA), and Etidronic acid (HEDP) solutions applied with sonic activation (SA) for 1 and 3 minutes during the final irrigation was evaluated in this in vitro study. Methods: Using 5 ml of 2.5% NaOCl irrigation solution in each sample, 70 mandibular premolars were enlarged with the Reciproc R25 rotary instrument system. The samples were randomly divided according to the final irrigation protocol into 6 experimental groups (n:10) and 1 control group (n:10): Group 1 (17% EDTA – 1 min SA), Group 2 (17% EDTA – 3 min SA), Group 3 (10% GA – 1 min SA), Group 4 (10% GA – 3 min SA), Group 5 (18% HEDP – 1 min SA), Group 1 (18% HEDP – 3 min SA) and Group 7 (Negative control group-distilled water, 1 min SA). The teeth were divided into two parts longitudinally after the final irrigation protocol. A low vacuum scanning electron microscope (SEM) was used to image the samples’ coronal, middle, and apical root areas at x2000 magnification. Samples were evaluated using a triple-scoring system. Results: Data were analyzed by Shapiro Wilk, Kruskal Wallis H, Mann-Whitney U, and Dunn’s tests. There was no statistically significant difference between EDTA, GA, and HEDP in both periods (p > 0.05). Conclusion: We saw similar amounts of erosion in dentin in 1 and 3 minutes of chelation applications for all chelators. Considering the smear removal efficiency of chelators, there is no harm in increasing the time in terms of erosion. There is a need for studies on the clinical applicability of chelation with a different duration time. How to cite this article: Okumuş ÖF, Kaya S, Adıgüzel Ö, Yeniçeri Özata M. Evaluation of time exposure of different irrigation agents on radicular dentin erosion. J Med Dent Invest 2022;3:e221170. https://doi.org/10.5577/jomdi.e221170 Linguistic revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English. Checked for plagiarism: Yes

Objective: In this study, we compared the occurrence of dentinal micro-cracks after use of the ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next (Dentsply Maillefer), and Reciproc (VDW, Munich, Germany) nickel–titanium rotary file systems in root canal preparation. Method: One hundred mandibular anterior teeth were divided into five groups of 20 specimens each. Group 1 served as a control, with no intervention. In group 2, preparation was performed using the step-back technique and K files. In groups 3–5, root canal preparation was performed using the ProTaper Universal, ProTaper Next, and Reciproc file systems, respectively. Following preparation, specimens were sectioned at 3, 6, and 9 mm using a Minitom precision cut-off machine. The sections were evaluated under a stereomicroscope. The following scoring system was used to rate specimens: 1, no micro-crack; 2, incomplete micro-crack; and 3, vertical root fracture. The results were statistically assessed (p ≤ 0.05). Results: No micro-crack formation was observed in groups 1 and 2. The highest rate of micro-crack formation was observed in specimens prepared with the ProTaper Universal file system (20%), followed by those prepared with the Reciproc (11.7%) and ProTaper Next (6.7%) file systems. However, no significant difference was detected among groups (p > 0.05). In the groups ProTaper Universal and Reciproc files were used, 1 vertical root fracture was found in 9 mm sections for each. Conclusion: Considering the limitations of in vitro studies, we can conclude that all rotary file systems used in this study led to dentinal micro-crack formation in roots. The ProTaper Universal file system caused more dentinal micro-cracking than did the ProTaper Next and Reciproc file systems.