Aim: The aim of this case report is to present a series of anatomical variations and endodontic treatments in four two-canal mandibular premolar teeth and three rooted three-canal maxillary second premolar teeth with root canal treatment indications identified via clinical and radiographic examinations. The success of root canal treatment is achieved with a thoroughly examined root canal morphology that has been accurately determined radiographically and clinically before adequate shaping, irrigation, and hermetic filling procedures. Root canals that are not found or not adequately disinfected can cause root canal treatment failure and complications, such as pain, swelling, or persistent fistula, also known as flare-up, after treatment. Canal variations in the teeth were detected via periapical radiographs during the root canal instrumentation stage. Methodology: The endodontic treatments of four two-canal mandibular premolar teeth and one triple-rooted three-canal maxillary second premolar with root canal treatment indications were described. Conclusion: To achieve full success in root canal treatment, anatomical variations should be examined in detail before and during treatment, and treatment should be completed with appropriate techniques. How to cite this article: Dinger E, Bodrumlu E. Treatment of anatomic canal variations in premolar teeth: Five case reports. Int Dent Res 2021;11(Suppl.1):279-84. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.41 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

The aim of this study is to evaluate tooth discoloration caused by different root canal sealers and the effect of subsequent bleaching treatment. In the present study, the coronal areas of the teeth whose crowns were cut and filled with the bioceramic root canal sealer and the resin-based root canal sealer, and before filling, after waiting for 1 week, 1 month and applying bleaching treatment. Color changes were observed. Resin-based root canal sealer group showed more coloration in the t2 measu

The purpose of this study was to evaluate the effect of three different post systems on the fracture resistance of maxillary incisors with simulated internal root resorption and extensive coronal structure loss. A total of 100 freshly extracted maxillary incisors were randomly divided into five groups (n = 20): glass fiber post, polyetheretherketone (PEEK) post, Ribbond post, positive control, and negative control. Internal resorption cavities were prepared 6 mm above the apex in each tooth, and the canals were filled using the single-cone technique with Sure-Seal Root bioceramic sealer. PEEK posts were digitally designed based on the dimensions of the glass fiber posts and fabricated in a dental laboratory. All posts were cemented using Panavia V5 resin cement according to the manufacturer’s instructions. The specimens were tested under static loading at a 45° angle using a universal testing machine until fracture occurred. Data were analyzed using one-way ANOVA and Tamhane’s post hoc test (P < .05). The highest mean fracture resistance was observed in the negative control group (1559.4 ± 209.1 N), while the lowest was in the positive control group (492.9 ± 73.4 N). Among the post-applied groups, the PEEK post group exhibited a significantly higher fracture resistance (907.4 ± 104 N) compared to the others (P < .001). Although all post systems increased the fracture resistance, none reached the strength of intact teeth. PEEK posts yielded the highest fracture resistance under the present experimental conditions.

Background: The aim of this study is to evaluate the diagnostic and treatment approaches of students who received endodontic practical training in the Objective Structured Clinical Examination (OSCE)-Objective Structured Practical Examination (OSPE) and phantom laboratory in the endodontics clinic. Materials and Methods: The study included 100 dental students from xxx Faculty of Dentistry who had received training in OSCE-OSPE and the phantom laboratory. In our survey study, which included two groups of questions covering 14 questions on diagnosis and treatment, the effects of preclinical education on the ability to diagnose and treat patients in endodontic clinical practice were evaluated. The One-Sample Chi-Square test was used for data analysis (p

This study examined whether direct pre-ozonation changes inhibition-zone diameters and selected chemical properties of endodontic irrigants. Sodium hypochlorite (NaOCl; 5.25%), chlorhexidine digluconate (CHX; 2%), ethylenediaminetetraacetic acid (EDTA; 17%), and saline underwent a fixed procedure (gas-phase ozone, 80 µg/mL; 30 L/h; 5 min; 200 mL). Disk diffusion against Candida albicans, Staphylococcus aureus, and Enterococcus faecalis was evaluated in eight independent paired runs. pH was measured, and available chlorine in NaOCl was determined in three independent paired batches. Mean inhibition-zone diameters were smaller after ozonation in all nine comparisons, and eight comparisons were statistically significant after Holm correction; the EDTA comparison against C. albicans was not statistically significant. CHX showed the largest pH change (9.05 to 6.34; −2.71 units). Available chlorine decreased from 5.10 ± 0.06% to 2.84 ± 0.04%, a paired reduction of 2.26 percentage points (95% CI, 2.02–2.50). Under this protocol, pre-ozonation did not increase inhibition-zone diameters. These findings cannot distinguish changes in intrinsic antimicrobial activity from altered agar diffusion and do not establish a clinical effect. Dissolved ozone was not measured, and chemical transformation products were not characterized.

The aim of this in vitro study was to compare three contemporary approaches for separated instrument retrieval: the Terauchi File Retrieval Kit (TFRK), the XP-endo Shaper combined with an ultrasonic system and the Meitrac Endo Safety System in terms of success rate, procedure time, dentin loss, and changes in canal volume. Sixty extracted single-rooted human premolar teeth were standardized and 5-mm-long nickel-titanium instrument fragments were placed in the middle third of the root canals. The specimens were divided into three groups (n = 20). All procedures were performed under a dental operating microscope. Success was defined as the complete removal of the separated instrument and procedure time was recorded. Dentin loss was determined using a precision analytical balance and changes in canal volume were evaluated using cone-beam computed tomography (CBCT) and three-dimensional segmentation analysis. The success rate was 85% in the TFRK and XP-endo Shaper groups and 80% in the Meitrac group (p > 0.05). The XP-endo Shaper group demonstrated a significantly shorter procedure time compared to the Meitrac group (p < 0.05). Dentin loss was lowest in the TFRK group and highest in the Meitrac group (p < 0.05). CBCT analyses indicated greater canal volume increase in the Meitrac group. These findings suggest that the XP-endo Shaper offers a faster approach, while TFRK provides a more conservative approach.