Single-visit nonsurgical endodontic retreatment presented fewer incidences of postoperative pain in comparison with 2-visit nonsurgical endodontic retreatment based on assessments ranging from 1 day to 1 month.

This study aimed to determine the intraradicular microbiota of previously root canal‐treated teeth with apical periodontitis and to investigate the antibacterial effectiveness of different intracanal medicaments. Sixteen patients with post‐treatment apical periodontitis were allocated into two groups according to the intracanal medicament used: calcium hydroxide (CH) and 2% chlorhexidine gluconate gel (CHX) group. Total bacterial loads, as well as the amount of Enterococcus faecalis (E. faecalis) were determined before (S1) and after (S2) chemomechanical preparation and finally, after intracanal medication (S3) by means of ddPCR. The unpaired t test was used to compare parametric. S3‐total bacteria copy number of the CH group was lower than the CHX group (p < 0.05). There was no statistical difference between the CHX‐ and the CH groups in terms of E.faecalis copy number (p > 0.05). But in terms of total bacteria, CH is better than CHX. Consequently, CH can be used to optimise the antibacterial efficiency of chemomechanical preparation in previously root canal‐treated teeth with apical periodontitis.

Background/Aim: This study aimed to evaluate the precision of the Raypex 6 apex locator in locating the apical constriction (AC) and major foramen (MF) during a root canal treatment compared with a microscopic evaluation. Another aim of the present study was to evaluate the accuracy of the Raypex 6 in the presence of different irrigating solutions (NaOCl, saline, EDTA, etidronic acid-HEBP). Material and Methods: One hundred and nine patients were included in this study and were randomly assigned into four groups according to the irrigation solution used; NaOCl, EDTA, HEBF and saline. Electronic MF (EMF) and AC (EAC) were measured by using Raypex 6. The teeth were extracted. The apical 3 mm of each canal was trimmed to expose the file tip. The samples were observed under a stereomicroscope, and the actual length of MF (ALMF) and AC (ALAC) were measured. The data were analyzed by using x2 test, and significance was set at P< 0.05. Results: The Raypex 6 was accurate 71.4% of the time to ±0.5mm and 93.3% of the time to ±1mm in determining the ALAC. While similar ALAC-EAC differences were observed in EDTA, NaOCl, and saline groups (p= 0.230), the highest differences were seen in the HEBP group (p= 1.000). The precision of Raypex 6 in determining the working length measurement depends on the type of irrigation. All solutions allowed reliable detection of AC. However, HEBF significantly increased the risk of overpreparation. Conclusions: Raypex 6 can be recommended for clinical use and its accuracy is not affected by the type of irrigant when locating MF.

A thorough understanding of the root canal morphology and correct evaluation of preoperative radiographs are essential for endodontic treatment. As many cases of endodontic treatment failure are due to missed canals, clinicians should be aware of all types of variations that may exist in the root canal system of each tooth.[1] Vertucci [2,3] (2005) classified morphological patterns of the root canal systems into eight types. In the simplest form, each root has a single canal and a single apical foramen (type I). However, other canal complexities that exit the root as one, two, or more apical canals (types II-VIII) exist. [2,3] In general, the mandibular second premolars have a single root and a single canal (Vertucci type I; 99.28% and 86.9%, respectively).[4] However, the incidence of a single root with two canals (Vertucci type V) in the mandibular second premolars is very rare (6.4%-29%). [5,6] Treatment failures and post-treatment flare-ups have been reported in these teeth, thus indicating too much variation in the morphology of mandibular second premolars. [7,8] To date, only a few retreatment cases of mandibular second premolars with one root and two canals have been reported in the literature. [9] This case report describes the successful retreatment of an unusual mandibular second premolar with Vertucci type V root canal morphology. Case reportA 39-year-old female patient was referred by her general dentist to the Istanbul Medipol University, Faculty of Mandibular premolars have been reported with complex anatomical aberrations, making endodontic treatment of these teeth extremely difficult. A case of endodontic retreatment of a mandibular second premolar exhibiting root canal bifurcation (Vertucci type V root canal configuration) of two apical foramina was described. A 39-year-old female with a non-significant medical history presented with a chief complaint of pain in a previously endodontically treated tooth. Clinical examination revealed tenderness to percussion. Intraoral periapical radiographs taken at different angulations revealed one root and two apical foramina. The main root canal was filled short of the apex and the other canal was not filled due to the broken file. Root canal retreatment was performed following the standard protocols. Although the prevalence of one root and two apical foramina in mandibular premolar is very low, clinicians should always be aware of variations in the number of roots and canals for the proper management of such cases.

S uccessful endodontic treatment has become an important and effective method for maintaining and preserving dental health. A thorough understanding of the root canal morphology and correct evaluation of preoperative radiographs are essential parts of endodontic therapy. Variations in the form of aberrant canal configurations, accessory canals, bifurcation, isthmuses, and anastomoses are often difficult to identify, thus creating a problem for endodontic treatment. [1] Failure to recognize and treat an extra canal might provide a constant source of irritation, thereby compromising the long-term success of the root canal therapy. [2] Vertucci [3,4] (2005) has classified morphological patterns of the root canal systems into