Efficacy of Potassium Titanyl Phosphate Laser and Sodium Hypochlorite on Postoperative Pain Intensity Following Pulpotomy in Teeth with Symptomatic Irreversible Pulpitis: A Randomized Clinical Trial.

Objective: This study evaluated the postoperative pain intensity in permanent teeth with symptomatic irreversible pulpitis treated by pulpotomy using physiological saline, sodium hypochlorite (NaOCl), or the potassium titanyl phosphate (KTP) laser. Materials and methods: Ninety patients diagnosed with symptomatic irreversible pulpitis in permanent molars were randomly divided into three groups according to the pulpotomy procedures. Preoperative pain levels were recorded. Complete hemostasis was achieved with physiological saline (control group), NaOCl, or the KTP laser after initial bleeding control. Patients were asked to mark their pain level on the visual pain scale at 6, 24, 48, and 72 h and 7 and 30 days depending on the severity of pain. The permanent restoration was completed after 7 days. Data were statistically analyzed using Kruskal-Wallis, Mann-Whitney U, Friedman, and Bonferroni tests at a significance level of p < 0.05. Results: According to the present study, the statistical difference between the groups in terms of preoperative pain and percussion pain levels was insignificant (p > 0.05). There was no significant difference between groups in terms of demographic data (p > 0.05). The postoperative pain level of the KTP laser group was significantly lower at 6 h compared with the saline group (p < 0.05). There was no significant difference between groups in terms of the postoperative pain level at other time intervals (p > 0.05). The highest pain scores were observed in all groups at 6 h (p < 0.05). Conclusions: The KTP laser can be preferred primarily for reducing postoperative pain in pulpotomy treatments. The KTP laser or NaOCl-assisted pulpotomy can be an effective treatment for pain reduction in permanent teeth with symptomatic irreversible pulpitis. This report is registered at clinicaltrials.gov (ID: NCT05424796).

Evaluation of the effect of calcium hydroxide paste on sealer penetration into dentinal tubules by confocal laser scanning microscopy.

The study evaluated sealer penetration after calcium hydroxide (Ca(OH)2 ) removal from the root canals. Sixty single-rooted mandibular premolars were divided into six groups. Ca(OH)2 paste placed into the root canals except for the control group (CG) was removed using the following irrigation techniques: conventional needle irrigation (CNI), EndoActivator (EA), EndoVac (EV), passive ultrasonic irrigation (PUI) and photon-induced photoacoustic streaming (PIPS) technique. After canal filling, the penetration depth, penetration area and penetration percentage of the sealer were determined using confocal microscopy. The CG and EA had a greater penetration depth than CNI in the middle section. The CG exhibited a higher dentinal tubule penetration area than CNI, EV and PUI in the middle section. EA was significantly more effective than PUI in the coronal section for the percentage of sealer penetration. EA and PIPS removed Ca(OH)2 from root canals effectively because they presented similar penetration to the CG in all sections.

Maxillary first premolars with three root canals: two case reports.

It is very important that the dentists have sufficient information about possible variations in the expected root canal configurations in order to achieve success in endodontic treatment. In addition to having adequate knowledge on the variations of the root canal anatomy, periapical radiographs from different angles, careful examination of the pulp chamber floor, and use of dental operation microscope during the procedure are also important factors that contribute to the diagnosis of the additional roots and canals. The aims of this article are to present the diagnostic approach and root canal treatments of two maxillary first premolar teeth with three canals in two patients.

Influence of Different Kinematics on Apical Extrusion of Irrigant and Debris during Canal Preparation Using K3XF Instruments.

INTRODUCTION: This in vitro study was designed to evaluate the amount of apically extruded irrigant and debris during root canal preparation using K3XF instruments (SybronEndo, Orange, CA) with different kinematics and using hand files with a step-back technique. METHODS: A total of 80 extracted mandibular premolars were selected and randomly assigned to 4 groups (n = 20). The root canals were instrumented with K-type stainless steel instruments using a step-back technique and with the K3XF system using the following kinematics: reciprocating motion, adaptive motion, and continuous rotation. Bidistilled water was used as an irrigant. Preweighed Eppendorf tubes were used to collect apically extruded debris during instrumentation. Extruded irrigant was collected from the drainage cannula using a plastic insulin syringe, and the volumes were recorded. After complete evaporation of the liquid inside the tube, the weight of extruded debris was determined for each specimen. Data were analyzed statistically using the Kruskal-Wallis and Mann-Whitney U tests at a significance level of P < .05. RESULTS: Hand file instrumentation was associated with a significantly greater extrusion of debris compared with the K3XF groups (P < .05). Among the different kinematics, the highest mean debris extrusion value was obtained with reciprocating motion and the least with continuous rotation, but this difference was not significant (P > .05). No significant differences were observed between groups in terms of irrigant extrusion (P > .05). CONCLUSIONS: Hand instrumentation extruded more debris than K3XF instruments that were used with different kinematics. All instrumentation kinematics were associated with apical debris and irrigant extrusion.

The Influence of Various Irrigants on the Accuracy of 2 Electronic Apex Locators in Locating Simulated Root Perforations.

INTRODUCTION: The aim of this study was to assess the accuracy of the Dentaport ZX (Morita Co, Kyoto, Japan) and the Rootor (Meta Biomed, Cheongwon-gun, Korea) electronic apex locators (EALs) in detecting root perforations in dry conditions and in the presence of the following irrigation solutions: 2.5% sodium hypochlorite (NaOCl), 0.9% saline solution (NaCl), and 17% EDTA. METHODS: Twenty extracted, single-rooted human teeth were perforated artificially in the middle section. The actual canal lengths (ALs) up to the perforation site were determined, and then the teeth were embedded in an alginate mold. The electronic measurements of the perforations were obtained using a size 20 K-file by each EAL in various conditions. For each tooth, the AL was subtracted from the electronic length of the perforation. Statistical analyses were performed using the Friedman and Wilcoxon signed rank tests at a significance level of P < .05. RESULTS: The most accurate measurements for both EALs were obtained in dry conditions. Among the irrigation solutions in the Dentaport ZX group, EDTA gave the most accurate results, and NaOCl gave the least accurate ones. However, measurements with NaCl were closer to the AL than those obtained with EDTA for the Rootor group. Significant differences were noted among the EALs when the measurements were taken with NaOCl, NaCl, and EDTA (P < .05). CONCLUSIONS: The Dentaport ZX was more accurate compared with the Rootor in the presence of different irrigants. The content of the root canal affected the accuracy of both EALs. The most accurate measurements were obtained in dry canals.

Reciproc versus Twisted file for root canal filling removal: assessment of apically extruded debris.

PURPOSE: The aim of this study was to evaluate the amount of apically extruded debris during endodontic retreatment with different file systems. MATERIALS AND METHODS: Sixty extracted human mandibular premolar teeth were used in this study. Root canals of the teeth were instrumented and filled before being randomly assigned to three groups. Guttapercha was removed using the Reciproc system, the Twisted File system (TF), and Hedström-files (H-file). Apically extruded debris was collected and dried in pre-weighed Eppendorf tubes. The amount of extruded debris was assessed with an electronic balance. Data were statistically analyzed using one-way ANOVA, Kruskal-Wallis, and Mann-Whitney U tests. RESULTS: The Reciproc and TF systems extruded significantly less debris than the H-file (p<0.05). However, no significant difference was found between the Reciproc and TF systems. CONCLUSION: All tested file systems caused apical extrusion of debris. Both the rotary file (TF) and the reciprocating single-file (Reciproc) systems were associated with less apical extrusion compared with the H-file.

Shaping ability of reciprocating single-file and full-sequence rotary instrumentation systems in simulated curved canals.

OBJECTIVE: The purpose of this study was to evaluate the shaping ability of three nickel-titanium systems in simulated curved canals. MATERIALS AND METHODS: Sixty simulated canals were prepared to apical size 25 with Reciproc, S5, and twisted file (TF) instruments. Standardized pre and postoperative images were taken using a digital camera, were superimposed and aberrations were recorded. Material removal was measured at five points: The canal orifice, halfway to the orifice, beginning of the curve, the apex of the curve, and end-point. The data were analyzed using Kolmogorov-Smirnov, analysis of variance, and Tukey tests. RESULTS: The mean total width of the prepared canals in the Reciproc group was greater than the TF and S5 groups at halfway to the orifice, the beginning of the curve, the apex of the curve, and the end-point (P < 0.05). Mean absolute transportation was always <0.16 mm; however, significant differences occurred between the three systems at the orifice, halfway to the orifice, and the beginning of the curve (P < 0.05). TF created minimal absolute transportation at halfway to the orifice and the beginning of the curve, and greater absolute transportation at the orifice compared with the Reciproc and S5 instruments. However, the difference between the S5 and TF groups was not statistically significant at halfway to the orifice (P > 0.05). CONCLUSIONS: Under the conditions of the study, Reciproc produced widest canal shapes. TF provided more centered apical preparation and maintained the original canal shape well.

In vitro comparison of working length determination using three different electronic apex locators.

BACKGROUND: The aim of this study was to compare the accuracy of the apex-locating functions of DentaPort ZX, Raypex 5 and Endo Master electronic apex locators (EALs) in vitro. MATERIALS AND METHODS: Thirty extracted human single-rooted teeth with mature apices were used for the study. The real working length (RWL) was established by subtracting 0.5 mm from the actual root canal length. All teeth were mounted in an alginate model that was especially developed to test the EALs and the teeth were then measured with each EAL. The results were compared with the corresponding RWL, which was subtracted from the electronically determined distance. Data were analyzed using a paired-samples t-test, a Chi-square test and a repeated measure analysis of variance evaluation at the 0.05 level of significance. RESULTS: Statistical analysis showed that no significant difference was found among all EALs (P > 0.05). CONCLUSION: The accuracy of the EALs was evaluated and all of the devices showed an acceptable determination of electronic working length between the ranges of ±0.5 mm.

The efficacy of two rotary NiTi instruments and H-files to remove gutta-percha from root canals.

OBJECTIVE: The aim of this study was to evaluate the efficacy of R-Endo® and K3® rotary nickel-titanium instruments compared with manual instrumentation with H-files, with use of a solvent, for removal of gutta-percha during retreatment. STUDY DESIGN: Forty five freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH 26® sealer. The teeth were randomly divided into three groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: Group 1 (H-files), Group 2 (R-Endo®), and Group 3 (K3®). The specimens were rendered transparent for the evaluation of the area of remaining gutta-percha/sealer in buccolingual and mesiodistal directions. Statistical analysis as performed by using one-way ANOVA and Kruskal-Wallis tests (p=0.05). RESULTS: All retreatment techniques used in this study left some filling material inside the root canal. Images in buccolingual and mesiodistal directions showed no significant differences between the groups (p>0.05). CONCLUSIONS: Under the experimental conditions, the remaining filling material after retreatment was similar for each group.

Bactericidal effect of KTP laser irradiation against Enterococcus faecalis compared with gaseous ozone: an ex vivo study.

OBJECTIVE: The objective of this study was to evaluate the antimicrobial activity of potassium-titanyl-phosphate (KTP) laser and gaseous ozone in experimentally infected root canals. STUDY DESIGN: Eighty single-rooted teeth with straight canals were selected. After preparation and sterilization, the specimens were inoculated with 10 microL Enterococcus faecalis for 24 hours at 37 degrees C. The contaminated roots were divided into 2 experimental groups, 1 negative control group, and 1 positive control group of 20 teeth each: Group 1, KTP laser group; Group 2, gaseous ozone group; Group 3, sodium hypochlorite group (NaOCl) (negative control); and Group 4, saline group (positive control). Sterile paper points used to sample bacteria from the root canals were transferred to tubes containing 5 mL of brain heart infusion broth. Then 10-microL suspension was inoculated onto blood agar plates. The colonies of bacteria were counted and data were analyzed statistically using Kruskal-Wallis 1-way analysis of variance and Mann-Whitney U tests. RESULTS: There were statistically significant differences between all groups (P < .05). The saline group had the highest number of remaining microorganisms. Complete sterilization was achieved in the 2.5% NaOCl group. The KTP laser and gaseous ozone did not completely sterilize the root canals. CONCLUSION: Both KTP laser and gaseous ozone have a significant antibacterial effect on infected root canals, with the gaseous ozone being more effective than the KTP laser. However, 2.5% NaOCl was superior in its antimicrobial abilities compared with KTP laser and gaseous ozone.

Apical extrusion of intracanal debris using two engine driven and step-back instrumentation techniques: an in-vitro study.

OBJECTIVES: The purpose of this study was to compare in-vitro the amount of debris extruded apically from extracted teeth, using K3, Protaper rotary instruments and manual step-back technique. METHODS: Forty five human single-rooted mandibular premolar teeth were randomly divided into 3 groups. The teeth in 3 groups were instrumented until reaching the working length with K3, Protaper rotary instruments and K-type stainless steel instruments with manual step-back technique, respectively. Debris extruded from the apical foramen was collected into centrifuge tubes and the amount was determined. The data obtained were analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests, with P=.05 as the level for statistical significance. RESULTS: Statistically significant difference was observed between K3, Protaper and step-back groups in terms of debris extrusion (P<.05). Step-back group had the highest mean debris weight, which was significantly different from the K3 and Protaper groups (P<.05). The lowest mean debris weight was related to K3 group, which was significantly different from the Protaper group (P<.05). CONCLUSIONS: Based on the results, all instrumentation techniques produced debris extrusion. The engine-driven Ni-Ti systems extruded significantly less apical debris than step-back technique. However, Protaper rotary instruments extruded significantly more debris than K3 rotary instruments.