The Effect of Reciprocating Instrument and Root Canal Filling Techniques on Post-operative Pain in Retreatment: A Prospective Clinical Study.

OBJECTIVE: The aim of this prospective clinical study was to assess the effect of different instruments and root canal filling techniques on post-operative pain in single visit of endodontic retreatment. METHODS: Forty five patients (18-65 yrs old) who needed non-surgical endodontic retreatment in mandibular premolar or molar teeth without any symptoms were included in this study. The teeth were randomly assigned into 3 groups of 15 teeth, according to the instrumentation and filling techniques: hand files with lateral compaction (group 1), Reciproc with lateral compaction (group 2), Reciproc with continuous wave compaction technique (group 3). Retreatments were performed in a single visit and post operative pain was assesed at 4 intervals; 24, 48,72 hours and 7 days. All data were analyzed using One way Anova, Chi-square and Fisher's Exact test and the significance level was set to (p≤0,05). RESULTS: No statistically significant difference was found among the groups in relation to post-operative pain (p>0.05). Although the intensity of post-operative pain was decreased over the time in all groups, significant difference was found only in Reciproc groups (p<0.05). However, no pain was found in any patient at the end of 7 day. Also, statistically significant difference was found between pain intense and periapical index in 24 and 72 hours (p<0.05). CONCLUSION: In the present study, the intensity of post-operative pain was not found to be related to instrumentation or filling techniques in retreatment cases. The intensity of pain could be related to periapical index of the tooth. (EEJ-2022-09-117).

Histological Investigation of the Cleaning Effectiveness of Different Biomechanic Processes of Isthmus in Lower Molars.

OBJECTIVES: This study aimed to evaluate the efficacy of different instruments (Hyflex, ROTATE, and hand files) and irrigation methods (EndoUltra, EndoActivator, and side-perforated syringe) in the mesial root canal of a mandibular first molar with isthmuses. MATERIALS AND METHODS: Sixty-three mandibular molar teeth with isthmus were selected using cone beam computed tomography (CBCT) images. The root canals were instrumented with Hyflex, ROTATE, or hand files (21 of each) and three of each as control group and the specimens were embedded in silicone blocks. Final irrigation was performed with the perforated syringe or ultrasonic (EndoUltra) or sonic irrigation (EndoActivator). All canals were irrigated using 5.25% NaOCl solution (15 mL). Then, the roots were stained with hematoxylin-eosin, and specimens were sliced for histologic evaluation. The isthmus regions (2.7, 3, 4.7, and 5 mm from the apex) were analyzed, and the percentage of debris was calculated. STATISTICAL ANALYSIS: All data were statistically analyzed using one-way analysis of variance and Tukey's tests. RESULTS: Both Hyflex and ROTATE groups showed less debris compared with the hand instrument group (P < 0.05). When irrigation methods were compared, EndoUltra showed the least, followed by EndoActivator and perforated needle irrigation having the maximum debris (p < 0.05). When sections were compared, the maximum debris was found in the apical section and the least in the coronal section (p < 0.05). CONCLUSION: Although none of the methods cleaned the isthmus completely, nickel-titanium (NiTi) systems and ultrasonic and sonic systems removed more debris than the side-perforated needle syringe irrigation.

Comparison of continuous wave and cold lateral condensation filling techniques in 3D printed simulated C-shape canals instrumented with Reciproc Blue or Hyflex EDM.

AIM: To compare the efficiency of continuous wave obturation and cold lateral condensation techniques and filling time in C-shape canals of 3-dimensional (3D)-printed resin teeth shaped with Reciproc Blue (VDW) or Hyflex EDM (Coltene/Whaledent). METHODOLOGY: One tooth with C1-type orifice and root canal morphology and one with C2-type orifice and C2-C3 root canal morphology were selected based on CBCT. Two replicas of selected teeth were manufactured with a 3D-printer and their canals were instrumented with Reciproc Blue or Hyflex EDM. These 4 instrumented replicas were scanned with CBCT. Identical 10 replicas of each group (total of 40) were produced using a 3D-printer and randomly divided into 2 groups (n = 5), root filled with either continuous wave obturation (CW) or cold lateral condensation (LC). Horizontal cross-sections of C1-type were made at 2, 4, 6, 8 mm and C2-type at 2, 4, 6 mm from the apical foramen. Gutta-percha, sealer and void areas were evaluated with image analysis sofware. Data were analysed using nonparametric Kruskal-Wallis and Mann Whitney-U tests and the Factorial ANOVA was used for interaction effects. Time required to fill canals was evaluated using the Mann-Whitney U test. RESULTS: For C1-type, LC had more gutta-percha and less sealer compared to CW in 2-mm sections (p<0.05). CW had greater percentages of gutta-percha and lower percentages of sealer compared with LC group in 4, 6, 8 mm sections and total area (p<0.05). LC group had higher percentages of voids compared to CW group in 2 and 4 mm sections (p<0.05). For C2-type, CW had more gutta-percha and less sealer versus LC group in all sections and total area (p<0.05). LC had the least gutta-percha and greatest sealer percentages at 6-mm sections (p<0.05). There was no statistically significant difference in the percentages of voids at any level of sections between the filling techniques (p>0.05). In both C-types, there was no significant difference in the percentages of gutta-percha, sealer and voids between Reciproc Blue and Hyflex EDM-shaped groups at any level (p>0.05). Time spent for the LC technique and filling C1-type was significantly longer than when using the CW technique and filling C2-type (p<0.05). CONCLUSIONS: Continuous wave obturation was more effective than lateral condensation in both C1- and C2-type, except for the apical 2 mm section of C1-type, suggesting the need for a modified CW technique.

Use of mineral trioxide aggregate in the treatment of large periapical lesions: reports of three cases.

Pulpal and periradicular pathosis are the result of microbial, mechanical, or chemical invasion. Microorganisms are the main irritants of pulpal and periapical tissues. The goal of the obturation is to obtain a fluid-tight seal of the root canal system from its coronal aspect through its apical extent to preserve from the irritants.. Root apices have morphological irregularities in teeth with periapical lesions. Therefore, it is more difficult to produce hermetically apical stop with conventional guttapercha obturation techniques. This case report describes the treatment and six years follow-up of the teeth with large periapical lesion using MTA as apical filling material.

Periapical status and quality of root fillings and coronal restorations in an adult Turkish subpopulation.

OBJECTIVES: To investigate the quality of root fillings and coronal restorations and their association with periapical status in an adult Turkish subpopulation. METHODS: A total of 400 subjects were examined. Panoramic radiographs of all participants and additional periapical radiographs of affected teeth were processed. The frequency of root canal treatment and the periapical status of all root filled teeth were evaluated. The relationship between the radiographic quality of root fillings and coronal restorations was examined by chi-squared statistical analysis. RESULTS: A total of 9460 teeth were examined. The total number of root filled teeth was 890 (9.39%), and 658 (73.9%) had apical periodontitis (AP). There was a significant correlation between the presence of periapical pathology and inadequate root canal fillings (P<.05). Presence of AP in root filled teeth was associated with inadequate adaptation of the filling (OR=1.097; P=0.54), and with poor radiographic quality of the coronal restoration (OR=0.91; P=0.70), and with poor radiographic quality of the filling restoration (OR=0.97; P=0.92). Only 24.5% of the root fillings were adequate. The highest percentage of root fillings was found in maxillary right first molars (6.9%). CONCLUSIONS: The results demonstrate a low prevalence of root-filled teeth and poor quality of coronal restorations and root fillings consistent with a high prevalence of apical periodontitis in a Turkish subpopulation.

Comparision of biocompatibility and cytotoxicity of two new root canal sealers.

The aim of this study was to investigate the remote organ toxicity and connective tissue reaction of two new root canal sealers ("GuttaFlow(®)" and "EndoREZ(®)") and to compare them with zinc oxide eugenol sealer using biochemical and histopathological parameters. A total of 60 white albino Wistar rats were used in the study. 0.1ml of GuttaFlow(®), EndoREZ(®) or Kerr Pulp Canal Sealer(®) were administered subcutaneously into the mid-dorsal thoracic region of rats (15 in each group). Control rats were given saline only. Rats were decapitated after 24h, on day 7 and on day 30 of the experiment and tissue samples from lung, liver, kidney and skin were removed for the determination of malondialdehyde (MDA) and glutathione (GSH) levels. In parallel, tissues were also examined histologically. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, and creatinine and blood urea nitrogen (BUN), concentrations (BUN) were measured to assess liver and kidney functions, respectively. Tumor necrosis factor (TNF) and lactate dehydrogenase (LDH) were also assayed in serum samples. No statistical differences were found among the control and EndoREZ(®), GuttaFlow(®) and Kerr Pulp Canal sealers regarding tissue MDA, GSH levels or serum parameters (p>0.05) at all time points examined. Both of the new root canal sealers showed good compatibility and acceptable tissue toxicity.

Comparison of the different techniques to remove fractured endodontic instruments from root canal systems.

OBJECTIVES: To evaluate the success of certain methods that can be used in the removal of separated instruments from different levels in curved and straight canals. METHODS: Instrument removal attempts were undertaken on 63 straight and 30 curved canals containing a pre-fractured instrument using the ultrasonics under the visualization of an operating microscope or conventional methods. In straight canals, a Masseran Kit was additionally used to these techniques. The success of instrument removal in relation to the techniques used and the location of the fragments in the root canal were evaluated. Successful treatment was defined by the removal or complete by passing of the fragments. RESULTS: The overall success rate was found 93.3% with ultrasonics and 66.6% when only conventional methods were used in curved canals. In straight canals, also the success rate was the highest with ultrasonics (95.2%). This was followed by conventional method (80.9%) and the least by Masserann Kit (47.6%). When the success rate was investigated according to the location of the broken instruments, the lowest rate was found in the apical third of root canal. CONCLUSIONS: Location of the fragment and the shape of the root canal influence the success of fractured instrument management. Ultrasonics under the visualization of an operating microscope was found to be an effective removal method.

Use of mineral trioxide aggregate in the treatment of horizontal root fractures with a 5-year follow-up: report of a case.

Root fractures are those that involve dentin, cementum, and the pulp. They occur more frequently in children than adults. This case report describes the treatment and 5-year follow-up of two maxillary central incisors with horizontal root fractures using mineral trioxide aggregate and the application of intracoronal bleaching of the discolored tooth.

Apical leakage of different gutta-percha techniques: thermafil, js quick-fill, soft core, microseal, system B and lateral condensation with a computerized fluid filtration meter.

OBJECTIVES: To investigate apical leakage of roots filled with 6 different gutta-percha techniques; Thermafil, JS Quick-Fill, Soft Core, Microseal, System B and lateral condensation using a new computerized filtration meter. MATERIALS AND METHODS: 60 extracted single rooted teeth were used. Coronal part of each tooth was removed and the root canals were prepared with step-back technique. The roots were randomly divided into six groups of 10 teeth, filled by one of the obturation technique and Kerr sealer. The teeth were kept in 100% humidity for 2 years. After this period, apical parts of roots (10 +/- 0.05 mm) were attached to computerized fluid filtration meter. Apical leakage quantity was determined as mul.cmH(2)O(-1).min(-1). RESULTS: Statistical analysis indicated that Thermafil, Soft Core, Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation (P < .05). However, statistically no difference was found among the core techniques and no difference was found between microseal and lateral condensation techniques (P > .05). CONCLUSIONS: Thermafil, Soft Core, Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation. In addition, this new computerized fluid filtration meter allowed quantitative measurement of leakage easily.

A comparison of four different microleakage tests for assessment of leakage of root canal fillings.

OBJECTIVE: The purpose of this study was to compare four different microleakage tests (dye leakage, electrochemical test, bacterial test and fluid filtration) for evaluation of the coronal seal of teeth obturated using Thermafil or lateral condensation techniques. STUDY DESIGN: One hundred forty-four extracted single-rooted teeth were selected and prepared. The specimens were divided into 8 experimental groups. In 4 groups the root canals were filled with Thermafil obturators and in the other 4 groups by the lateral condensation technique. Coronal microleakage was assessed after exposing one group of specimens (n = 15 teeth) from each of the obturation techniques to each of the four microleakage tests. RESULTS: In the fluid filtration test, lateral condensation showed statistically less leakage than the Thermafil technique (P < .05). Electrochemical and dye leakage test results showed no difference between the two obturation techniques (P < .05). However, in the bacterial leakage test, Thermafil showed less leakage than lateral condensation (P < .05). CONCLUSION: There is poor correlation between various methods to evaluate hydraulic leakage. The clinical significance of leakage tests in vitro is questionable.

Histologic study of furcation perforations treated with MTA or Super EBA in dogs' teeth.

OBJECTIVE: The aim of this study was to investigate the histologic response to MTA or Super EBA when used for the repair of furcation perforations in dogs' teeth. STUDY DESIGN: Ninety mandibular premolar and molar teeth of 9 mongrel dogs were used in this study. The teeth were divided into 3 groups. Seventy-two teeth were repaired with either MTA or Super EBA (36 each), and 18 teeth were not repaired and used as negative controls. All groups were histologically examined at 1 month, 3 months, and 6 months after treatment. Histologic evaluation was done with regard to inflammation and type of healing. RESULTS: The Super EBA group showed moderate inflammation in 1 month; the inflammation decreased over time, but most of specimens showed inflammatory reaction from mild to severe at the end of 6 months. The perforation area was filled by connective tissue in specimens in which no inflammation was seen. In the MTA group, mild inflammation was seen in 1 month, it decreased in 3 months, and no inflammation was detected in 6 months. New cementum formation was taken in place in 4 specimens in 1 month, in 8 specimens in 3 months, and in all specimens in 6 months. CONCLUSIONS: MTA showed less inflammation than Super EBA. MTA specimens showed healing with new cementum formation in the perforation area, whereas Super EBA specimens in which no inflammation was seen showed connective tissue healing.

Comparison of 6 different gutta-percha techniques (part II): Thermafil, JS Quick-Fill, Soft Core, Microseal, System B, and lateral condensation.

OBJECTIVES: In this in vitro study, the core-to-sealer ratios were calculated for 6 different gutta-percha techniques: Thermafil, JS Quick-Fill, Soft Core, Microseal, System B, and lateral condensation. The core consisted of gutta-percha or gutta-percha and carrier. STUDY DESIGN: The sealer-to-core ratios for the Thermafil, JS Quick-Fill, System B, and lateral condensation techniques were published previously. In this study, the sealer-to-core ratio for Microseal and Soft Core techniques was investigated. For this purpose, 20 teeth filled by using the Soft Core or the Microseal technique were embedded in resin and sectioned horizontally at 1, 2, 3, and 4 mm from the anatomic apex. Photographs were taken of each section, and the total area of the canals filled with core material or sealer was calculated. RESULTS: Once all results were compiled, it became clear that core techniques (Thermafil, JS Quick-Fill, and Soft Core) produced higher gutta-percha content than the Microseal, System B, and lateral condensation techniques (P <.05). The lateral condensation technique produced the least gutta-percha content (P <.05). CONCLUSION: Thermafil, JS Quick-Fill, and Soft Core were found to be superior to the Microseal, System B, and lateral condensation techniques in terms of the gutta-percha-to-sealer ratio.

Canal length evaluation of curved canals by direct digital or conventional radiography.

OBJECTIVES: The purpose of this study was to compare the accuracy of a digital radiograph imaging system (DDR) with conventional radiography for the purpose of estimating endodontic file lengths in curved canals of mandibular molars. STUDY DESIGN: Sixty extracted human mandibular molars with root curvatures ranging from 5 degrees to 52 degrees were mounted in plastic blocks. Canal length was estimated by using on-screen DDR with both 2- and 3-click measurement and from conventional E-speed radiographs by using a millimeter ruler and x2 magnification. Two operators familiar with both radiographic methods performed the estimates. RESULTS: One-way analysis of variance and Newman-Keuls tests revealed no significant differences between the groups. Although both conventional and DDR methods of analysis overestimated the true canal length, the DDR accuracy improved as the curvature severity increased. CONCLUSIONS: The image quality of DDR systems has improved to the point that they can now be used for estimating canal lengths, even for curved canals, with accuracy comparable to that of conventional radiographs. However, further work remains to be done to optimize image quality.