Lateral Condensation Of Gutta-percha Research Articles

Root canal filling quality and bond strength of endodontic sealers to human and bovine dentin

Objective: This study aimed to compare the filling quality and bond strength of two endodontic sealers, AH Plus and Bio-C Sealer, in human and bovine teeth. Methods: The root canals of 60 [30 human (H) and 30 bovine (B)] single-rooted teeth were prepared and filled by lateral condensation of gutta-percha and AH Plus (groups AP-H and AP-B) or Bio-C Sealer (groups BC-H and BC-B). Six 1.5-mm-thick slices were obtained from each root. The specimens were observed under a stereomicroscope to assess filling quality, considering possible voids within the filling material. Subsequently, root slices were evaluated in terms of push-out bond strength and failure mode. Data were analyzed by Mann-Whitney tests and Spearman correlation coefficients (α=5%). Results: The filling quality provided by AP and BC was similar in both dentin substrates. However, when comparing human and bovine teeth, void scores were greater in the bovine samples, for both sealers. AP had higher bond strength to human and bovine dentin than BC. However, there was no significant difference in bond strength between dentin substrates, for both sealers tested. Also, there was a positive and moderate correlation between the bond strength values of human and bovine teeth. The mixed failure mode was the most prevalent. Conclusion: AP and BC provide similar filling quality, but the first presents higher bond strength values to human and bovine dentin. The use of bovine teeth as substitutes for human samples seems adequate in studies related to bond strength, but not in those testing root canal filling quality.
 Keywords: Dentin, Endodontics, Root canal filling materials.

АКТИВАЦИЯ РАСТВОРА АНТИСЕПТИКА В ИСКРИВЛЕННЫХ КОРНЕВЫХ КАНАЛАХ КАК ЗАЛОГ УСПЕШНОГО ЭНДОДОНТИЧЕСКОГО ЛЕЧЕНИЯ

Endodontic treatment of teeth characterized by a complex anatomy of root canals is an urgent problem of modern dentistry. This article compares the immediate and long-term results of treatment of curved root canals using the sound method of activation of irrigation solution and the standard method of treatment, in which the activation of the solution was not carried out. The purpose of the study: to increase the effectiveness of endodontic treatment of root canals with complex anatomy by using sound methods. Materials and methods: Molars and premolars were examined and treated in 50 patients aged 25-44 years with a diagnosis of chronic apical periodontitis (K 04.5). The diagnosis was established on the basis of basic and additional research methods. The patients underwent diagnostic CBCT before treatment, as well as 6 and 12 months after treatment. The main group consisted of 25 patients in whom sound activation of a 3% sodium hypochlorite solution was used in the treatment of root canals at the stage of final root canal treatment, the control group consisted of 25 patients who used a standard technique of root canal irrigation from an endodontic syringe. Endodontic treatment in patients of both groups was carried out according to the standard protocol of root canal treatment. Mechanical processing was carried out with manual endodontic instruments, and then with machine Ni-Ti files. Drug treatment was carried out with 3% sodium hypochlorite solution and 17% EDTA solution. During the first visit after mechanical and medical treatment, the root canals of patients of both groups were temporarily obstructed with calcium-containing paste "Calasept". Permanent obturation of the root canal was carried out by the method of lateral condensation of gutta-percha, a material based on epoxy resins "AH plus" was used as a siler. As a result of the study, it was revealed that the patients of the main group did not complain in the next 3-7 days after the end of treatment. Dental percussion and mucosal palpation were painless in 23 patients. Slightly pronounced mucosal hyperemia and discomfort during palpation in the projection area of the root tips along the transitional fold were determined in 2 patients. In the control group of patients, during the first 7 days after permanent obturation of the root canals of the teeth, 5 people had pain when biting on the tooth, painful percussion and hyperemia of the mucous membrane in the projection of the root tip of the treated tooth. The remaining 20 patients had no complaints. The analysis of radiographs revealed that 12 months after treatment in patients of the main group, a decrease in the size of periapical foci of bone destruction was noted in all 25 teeth. In 23 teeth there was a complete restoration of the bone structure in the periapical foci, which was 92%, and in 2 teeth there was a partial restoration of the bone structure (6%). The condition without changes in the periapical tissues, or an increase in the focus of bone destruction in patients of the main group 12 months after treatment, we have not been detected. When analyzing radiographs in patients of the comparison group in 19 (76%) teeth there was a complete restoration of the bone structure in the periapical region and in 5 (20%) teeth there was a partial restoration of bone tissue from the teeth. In 1 (4%) tooth, foci of bone tissue destruction were determined on radiographs, the size of which remained unchanged. Thus, the use of a sound method of activating a 3% sodium hypochlorite solution in teeth with a complex root canal anatomy at the stage of finishing irrigation makes it possible to effectively clean the root canal from the lubricated layer, which contributes to high-quality root canal obturation and a significant reduction in immediate and long-term complications after treatment.

ОСОБЕННОСТИ ЭНДОДОНТИЧЕСКОГО ЛЕЧЕНИЯ ЗУБОВ С ЭНДОПАРОДОНТАЛЬНЫМ ПОРАЖЕНИЕМ КАК ЗАЛОГ КАЧЕСТВЕННОГО ПРОТЕЗИРОВАНИЯ

The problem of treatment of teeth with endoparodontal lesions remains relevant today. This article discusses a clinical case of treatment of a patient with chronic generalized periodontitis who has a combined lesion of the periodontal and apical periodontal in the lower premolar region. The purpose of the study is evaluation of the effectiveness of the treatment of endoparodontal tooth lesion and the further possibility of prosthetics of the tooth. Materials and methods. For the diagnosis of pathology and in the course of treatment, the following additional research methods were used: CT, OPTG and targeted radiography. Mechanical processing was carried out with manual steel tools. Drug treatment was carried out using solutions of 3% sodium hypochlorite and 17% EDTA For temporary obturation of the root canal, a material based on calcium hydroxide with the addition of a radiopaque substance was used. To further improve the quality of disinfection and adhesion of the filling material to the root canal wall, the method of photodynamic action on the root canal wall was applied in the 2nd visit. Permanent obturation of the root canal was carried out by the method of lateral condensation of gutta-percha in combination with a siler based on ecoxide resin. The reduction of the focus of bone tissue destruction was confirmed clinically and radiologically. Thus, we managed to avoid tooth extraction and it became possible to use this tooth as a support on a non-removable orthopedic structure.

Periapical Healing of Mandibular Posteriors Having Calcific-Like Deposits: A Rare Case Report

The aim of this paper is to present an interesting case of a periapical healing of mandibular posteriors having calcific-like deposits with radiolucent lesion. A 35-year-old healthy female patient was referred to our clinic by a general dentist. A diagnosis of calcific-like deposits with apical periodontitis lesion on the root surfaces with pulp necrosis was made. The root canal was prepared using the sequential hand files and rotary files. In the first session, calcium hydroxide was applied to the root canals to treat the radiolucent lesion. A one-week break was taken between the first and second session, and finally, the canals were filled with standard cold lateral gutta-percha condensation. No clinical signs were detected in the clinical examination of the controls, and the calcific-like deposits on the root surfaces and radiolucent lesion were healed in follow-up x-rays. The cases presented showed acceptable functional and/or successful recovery without recurrence at follow-up examination.

Evaluation of the sealer/gutta-percha ratio on sets of root section surfaces of some extracted teeth sealed using the cold lateral condensation technique.

Canal filling must be well adapted to the walls of the root canal to prevent bacterial infiltration. Endodontic seals play an essential role in ensuring tightness, without which the canal filling would suffer infiltrations. This study aimed to evaluate the areas occupied by the two components of the canal filling, as well as the sealer/gutta-percha ratio in the root canals of the maxillary central incisors after their filling using the cold lateral condensation technique with gutta-percha. Thirty extracted upper central incisors were rotatably prepared with ProTaper Universal up to F3 and sealed using the cold lateral condensation technique with gutta-percha. After setting the sealer, the roots of the teeth were sectioned perpendicularly to 1 (L1), 3 (L3), 6 (L6), and 8 (L8) mm from the apex. The surface of the sections was analyzed with a Leica EZ4D stereomicroscope and photographed at two magnification orders: 10x and 25x. The areas corresponding to the gutta-percha, sealer, gaps, and root canal were expressed in pixels using the ImageJ software, version 1.50i. The difference in the representation of sealer areas, gutta-percha and voids was statistically significantly different for all four sections analyzed. The best adaptation of the canal obturation was observed in L1 and L3. The gutta-percha area was statistically significantly higher than that of the sealer for the L1, L3, and L6 levels, while the sealer/gutta-percha ratio recorded the lowest value at the L3 level (0, 30) and the highest at its L8 (0.70) level, without registering statistically significant differences regarding the area at the four analyzed levels. The voids were mostly absent or recorded a minimal percentage area (<1%). Cold lateral condensation of gutta-percha has led to a good adaptation of gutta-percha to the root canal wall, with a small amount of sealer, especially to the sections made at 3 mm from the apex. Given the limitations of this study, we noted that the voids were few – observed in the 6 and 8 mm sections – and were negligible in many cases.

Comparative study of the effectiveness of methods of root canals filling with cold high-flow gutta-percha in the experiment

Objective : Assessment of the quality of root canal obstruction by the method of cold high-flowing gutta-percha in comparison with standard methods of filling. Methods : In vitro experiment on 60 extracted teeth with one root canal. In 20 teeth, the canals were obturated by lateral condensation of gutta-percha, in 20 – by a central conical pin, and in another 20 – fluid cold gutta-percha with a gutta-percha pin. Visiography was performed, then after polymerization of the sealer, the root was sawn in the transverse direction and the quality of the filling was evaluated using digital microscopy. Results : In the first two groups, satisfactory results were obtained with a homogeneous filling of the lumen of the root canal. In the third group, unsatisfactory results were obtained in 65 % of cases: lack of sealer in the middle and apical parts of the canal, filling defects. Conclusions : The technique of lateral condensation of gutta-percha and the method of filling with a conical central pin with a polymer endo sealer significantly exceed the quality of filling cold high-flowing gutta-percha.

In Vitro Comparison of Efficacy of Neolix and ProTaper Universal Retreatment Rotary Systems in Removal of Gutta-Percha Combined with Two Different Sealers

Statement of the Problem:The complete removal of filling material is an important step to regain access to the entire canal and facilitate the disinfection of the root canal system. Rotary nickel-titanium (NiTi) instruments systems have been proposed as an effective removal technique for root canal retreatment. Purpose:The aim of this study was to evaluate the efficacy of Neolix rotary system and ProTaper Universal retreatment system in the removal of gutta-percha combined with two different sealers. Materials and Method: In vivo study, eighty extracted human permanent mandibular premolars were prepared using the ProTaper Universal rotary system to an apical size 30 (F3/0.06). The specimens were randomly divided into 4 groups (n=20) and subsequently filled with lateral condensation of gutta-percha and two sealers: AH-26 and Sure-Seal Root. The teeth were stored for 4 weeks at 37°C and 100% humidity and then retreated by one of the following rotary systems: Neolix or ProTaper Universal retreatment system. Teeth were then grooved and monitored under a stereomicroscope with 8× magnification. The images were transferred to the computer and the amount of filling material that remained on the root canal walls was scored using AutoCAD 2017 version 1.1software. Results were analyzed using one-way analysis of variance test and post hoc Tukey-HSD test (p< 0.05). Results:The mean percentage of remaining gutta-percha and sealer was significantly higher in apical third in all groups (p< 0.01). Post hoc Tukey test showed that there is significantly higher residual filling material in the group filled with gutta-percha and Sure-Seal Root sealer and retreated by Neoniti rotary system compared with other groups in both coronal and middle third of the canal. Conclusion:The Neoniti rotary system was as effective as ProTaper Universal retreatment system in retreatment of gutta-percha and AH-26 sealer but was significantly less effective in groups obturated with Sure-Seal Root sealer.

In Vitro Comparison of Efficacy of Neolix and ProTaper Universal Retreatment Rotary Systems in Removal of Gutta-Percha Combined with Two Different Sealers.

The complete removal of filling material is an important step to regain access to the entire canal and facilitate the disinfection of the root canal system. Rotary nickel-titanium (NiTi) instruments systems have been proposed as an effective removal technique for root canal retreatment.The aim of this study was to evaluate the efficacy of Neolix rotary system and ProTaper Universal retreatment system in the removal of gutta-percha combined with two different sealers.In vivo study, eighty extracted human permanent mandibular premolars were prepared using the ProTaper Universal rotary system to an apical size 30 (F3/0.06). The specimens were randomly divided into 4 groups (n=20) and subsequently filled with lateral condensation of gutta-percha and two sealers: AH-26 and Sure-Seal Root. The teeth were stored for 4 weeks at 37°C and 100% humidity and then retreated by one of the following rotary systems: Neolix or ProTaper Universal retreatment system. Teeth were then grooved and monitored under a stereomicroscope with 8× magnification. The images were transferred to the computer and the amount of filling material that remained on the root canal walls was scored using AutoCAD 2017 version 1.1software. Results were analyzed using one-way analysis of variance test and post hoc Tukey-HSD test (p< 0.05).The mean percentage of remaining gutta-percha and sealer was significantly higher in apical third in all groups (p< 0.01). Post hoc Tukey test showed that there is significantly higher residual filling material in the group filled with gutta-percha and Sure-Seal Root sealer and retreated by Neoniti rotary system compared with other groups in both coronal and middle third of the canal.The Neoniti rotary system was as effective as ProTaper Universal retreatment system in retreatment of gutta-percha and AH-26 sealer but was significantly less effective in groups obturated with Sure-Seal Root sealer.

Assessment of Two Root Canal Sealers Push-out Bond Strength in Root Canals Obturated Using Two Different Obturation Techniques

Background: The aim was to compare the push-out bond strength of calcium silicate-based sealer Total Fill BC Sealer with an epoxy resin-based sealer Adseal used in cold lateral and single cone obturation techniques. Materials and Methods: Forty-eight single-rooted teeth with completely formed apices were selected. Teeth were decoronated, and working length was determined. Instrumentation and irrigation were performed. The teeth were equally and randomly divided into four groups (n=12) according to the obturation technique and the root canal sealer used as follow; Group I: Root canals were obturated using gutta percha & Totalfill bioceramic sealer by using single cone technique single cone technique, Group II: Root canals were obturated using gutta percha lateral condensation technique & Totalfill bioceramic sealer, Group III: Root canals were obturated using gutta percha & Adseal sealer by using single cone technique, and Group IV: Root canals were obturated using gutta percha & Adseal sealer by using lateral condensation technique. Manipulation and application of the sealer was done according the manufacturer instructions. All teeth were stored in an incubator at 37 °C and 100% humidity for 1 week to allow complete setting of the root canal sealers. Each root was prepared for push-out test using universal testing machine with root slices of 2 mm thickness were obtained at 3, 7, 11 mm from apex representing (apical, middle, and coronal) respectively, and the push-out bond strength was calculated. Statistical analysis was performed using One-way ANOVA followed by Tukey post hoc t-test was used to compare between more than two groups in non-related samples. Results: The highest bond strength was found in Group II (Totalfill & cold lateral obturation technique) (P < 0.05) compared to other groups. The lowest bond strength was found in Group III (Adseal & single cone obturation technique). Conclusion: The push-out bond strength of Totalfill & Adseal root canal sealers with cold lateral obturation technique were highest followed by Totalfill& single cone technique and lowest bond strength was observed in Adseal & single cone on obturation technique. Higher push out bond strength values recorded in apical and middle thirds than coronal third.

Vertical Root Fracture in Buccal Roots of Bifurcated Maxillary Premolars from Condensation of Gutta-percha

IntroductionMaxillary premolars are among the teeth most susceptible to vertical root fracture (VRF) from lateral condensation of gutta-percha. These teeth are distinguished by a complex anatomy of the buccal root including a large depression in the dentin wall facing the bifurcation. It is hypothesized that tooth sectioning coupled with 2-dimensional fracture analysis is instrumental in understanding VRF in such teeth. VRF was examined by tooth sectioning following the development of a fracture mechanics analysis to predict VRF in such roots. MethodsThe fracture morphology in teeth extracted from patients because of VRFs was examined from a series of horizontal cross sections. 2-dimensional fracture mechanics analysis in conjunction with the finite element technique was developed to evaluate VRF caused by canal pressure (q). As in our previous single-rooted tooth model, the apical obturation force (F) was related to q using a simple formula. ResultsFracture was mostly limited to the buccal root, exhibiting some competing modes including fracture from the depression peak to the canal surface and the canal surface to the root surface, which may occur either along straight lines or curved trajectories resembling the depression outline. The analysis predicted clinical fractures well, yielding VRF force values in the upper range used by clinicians during lateral condensation of gutta-percha. ConclusionsThe main etiology for VRF is stress concentration resulting from the combined effect of wedgelike canal depression and the flexibility of periodontal ligament tissue joining the root and bone. This drawback can be alleviated by minimizing canal enlargement and apical condensation force during root canal therapy.

Thermafil: A New Clinical Approach Due to New Dimensional Evaluations.

Background:There are a lot of techniques to obturate the root canals, but lateral condensation of gutta-percha is the most used one. An important aspect of thermafil is the error margin tolerated by the manufacturer in the production of plastic carriers. In literature, there is no evidence about discrepancy percentage between different carriers. It is demonstrated that the error margin of gutta-percha is 0.5% and is 0.2% for metal files (ISO standards).Objective:The aim of this study was to evaluate the real dimensions of thermafil plastic carriers observed by the stereo microscope measuring the dimensional discrepancy between them.Methods:For this study, 80 new thermafil (Dentsply Maillefer) have been selected. 40 thermafil 0.25 and 40 thermafil 0.30. Through 60X stereo microscope, the dimensions of the plastic carrier tips have been measured. The dimensions of the plastic carrier were also measured after a heating cycle. ZL GAL 11TUSM (Zetaline stereo evolution) microscope was used to observe the samples. Measurements were made through a dedicated software (Image Focus). All samples were analysed at 60X.Results:A non-parametric paired test (Wilcoxon test) was used to compare baseline and after heating values; p-values ≤ 0.05 were assumed to be statistically significant.Conclusion:The samples we measured showed a mean value of the diameters in Thermafil 25 that was 0.27 mm, for Thermafil 30 the mean value was 0.33 mm.We have measured a dimensional variable of 8% in the 25 group while in group 30 the maximum possible variation found was 4%, that’s why we propose a new protocol of obturation with thermafil. We can also conclude that a single heating process does not affect clinically the plastic carrier dimensions.

Efficacy of rotary and reciprocating single-file systems on different access outlines for gutta-percha removal in retreatment: An in vitro study.

Introduction:The aim of this study is to compare the effectiveness of reciprocating and continuous rotary nickel-titanium instruments during retreatment performed through two different access outlines.Methodology:A total of 48 freshly extracted mandibular first and second premolars with single root and canal were selected. Initial root canal treatment was completed through a contracted endodontic cavity (CEC) design. Canals were instrumented with F2 ProTaper instrument, obturated with warm lateral condensation of gutta-percha with AH Plus sealer, and allowed to set for 30 days at 37°C and 100% humidity. For retreatment, specimens were divided into two groups (n = 24) on the basis of access outline, CEC or traditional endodontic cavity. Retreatment was initiated using ProTaper Retreatment instruments (D1–D3). Specimens were further divided (n = 12) and reinstrumented up to Neoniti 25/0.08 or WaveOne 25/0.08. Irrigation was performed using 3% sodium hypochlorite and 17% ethylene diamine tetraacetic acid. Retreatment time was recorded. Teeth were sectioned and photographed, and the percentage of remaining obturation material was measured.Results:Data were collected, and statistical analysis was performed using one-way analysis of variance and Tukey honestly significant difference multiple post hoc procedures (P < 0.05).Conclusion:None of the systems completely removed the root filling material from root canals. However, ProTaper/Neoniti instruments removed more GP when compared to Protaper/WaveOne instruments with both the access outlines. Both the instruments with traditional access outline required less time for removal of obturating material when compared to CEC.

Apical dye leakage of two single-cone root canal core materials (hydrophilic core material and gutta-percha) sealed by different types of endodontic sealers: An in vitro study.

Aim of the Study:The aim of this study was to compare the apical sealing ability of two single-cone filling materials when sealed with different types of root canal sealers.Materials and Methods:Eighty extracted maxillary and mandibular canines were selected and their crowns were cut. The root canals were prepared using ProTaper Universal rotary system until size F4 and then divided into seven experimental groups (n = 10 each) and two control groups (n = 5 each). Samples of Groups 1, 2, and 3 were filled with single-cone gutta-percha and AH Plus, MTA Fillapex, and EndoSequence BC, respectively. Samples of Groups 4, 5, and 6 were filled similar to the previous groups with the exception of using a single-cone CPoint. Samples of Group 7 were filled with cold gutta-percha lateral condensation technique. To assess apical microleakage, the apical linear dye penetration was measured microscopically and data were statistically analyzed.Results:All experimental groups showed significantly different dye apical leakage values (P = 0.000). No significant differences were found between Groups 1, 2, 4, 6, and 7 (P < 0.05). The lowest mean leakage value was observed in Group 6 (0.95 ± 0.56 mm) while Groups 3 (2.68 ± 0.71 mm) and 5 (2.61 ± 0.71 mm) showed significantly higher mean leakage values.Conclusions:The lowest apical leakage value was observed with single-cone CPoint/EndoSequence BC but without significant differences when compared with single-cone gutta-percha/AH Plus, single-cone gutta-percha/MTA Fillapex, single-cone CPoint/AH Plus, and lateral condensation technique. Higher apical leakage values were observed with single-cone gutta-percha/EndoSequence BC and CPoint/MTA Fillapex.

Influence of the Calcium Hydroxide Intracanal Dressing on Dentinal Tubule Penetration of Two Root Canal Sealers.

Objective:The aim of this study was to evaluate the effect of a calcium hydroxide (CH) dressing on the tubular penetration of two endodontic sealers, AH Plus (Dentsply Maillefer, Ballaigues, Switzerland) and MTA Fillapex (Angelus, Londrina, Brazil).Methods:Seventy-two mandibular premolars with a single root canal were prepared with ProFile.04 rotary instruments (Dentsply Maillefer) and divided into four groups. In two groups, an intracanal CH dressing was placed for 15 days. The obturations were performed with lateral condensation of gutta-percha in combination with one of the tested sealers. The roots were transversely sectioned at the apical and middle levels. The percentage of sealer penetration in the root canal walls and the percentage of impregnated dentin area in the transverse sections were obtained using confocal laser scanning microscopy. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Games-Howell test.Results:The CH dressing reduced the mean value of tubular penetration in the middle third of teeth obturated with AH Plus (P<0.01), whereas no difference was observed at the apical sections for both sealers.Conclusion:The CH dressing did not interfere with the apical penetration of both tested sealers, however, decreased the tubular penetration in the middle third of the AH Plus root canal fillings. Overall, MTA Fillapex presented higher tubular penetration than AH Plus obturations.

Effect of ultrasonic and sonic activation of root canal sealers on the push-out bond strength and interfacial adaptation to root canal dentine.

To evaluate the effect of ultrasonic and sonic activation of two root canal sealers on interfacial adaptation and push-out bond strength (BS) to root canal dentine. The root canals of seventy-eight roots of maxillary canines were prepared with NiTi rotary instruments under irrigation with 2.5% NaOCl and 17% EDTA. Canals were filled by lateral condensation of gutta-percha and AH Plus (n=39) or MTA Fillapex (n=39). Three subgroups (n=13) were formed according to sealer activation: no activation (NA), sonic activation (SA, 20s) and ultrasonic activation (US, 20s). In three specimens of each subgroup, 0.1% rhodamine B was added to the sealer. Three 1-mm-thick slices were obtained from each root third. The first and second were used for push-out BS test and the third for a qualitative analysis of interfacial adaptation (gaps) and voids by confocal laser scanning microscopy (CLSM). Intratubular penetration of rhodamine B-labelled sealer was also assessed by CLSM. Data were analysed by two-way anova and Tukey's test (α=0.05). AH Plus (2.58±1.21) had higher push-out BS than MTA Fillapex (1.45±0.71) (P= 0.000). UA (2.64±1.44) had higher BS (P=0.000) than NA (1.58±0.73) and SA (1.83±0.85), which did not differ significantly from each other (P= 0.3303). The coronal third had higher BS (2.48± 1.49) than the middle (2.08±0.94) (P=0.0003) and apical (1.48±0.58) (P=0.00) thirds. For both sealers, UA was associated with a more homogeneous filling material with better interfacial adaptation and greater quantity, density and length of tags in dentinal tubules. When UA was used, the tags had similar quantity, density and length to those formed without activation, but interfacial gaps and voids were observed. Ultrasonic activation was associated with higher BS values, deeper intratubular penetration and greater interfacial adaptation to root dentine than sonic activation and no activation techniques, AH Plus had higher BS values than MTA Fillapex irrespective of the type of activation.

EVALUAREA MATERIALULUI DE OBTURAŢIE DE CANAL RESTANT DUPĂ DEZOBTURARE, FOLOSIND PROTAPER ROTATIV CU SAU FĂRĂ SOLVENŢI

The purposes of retreatment are to eliminate the cause for failure of initial endodontic treatment and to preserve the tooth as well. The aim of this study is a comparative evaluation of efficacy of Protaper rotaty retreatment instruments for gutta-percha removal with or without solvents specific both to the sealer and gutta-percha. Materials and methods: Forty single-rooted extracted teeth were randomly divided into 4 groups according to different methods of retreatment. The teeth were prepared with Protaper Universal system (Dentsply-Maillefer, Ballaigues, Switzerland) and filled using lateral condensation of gutta-percha and AH Plus (Dentsply DeTrey, Konstanz, Germany). All root canal fillings were removed using Protaper Universal Retreatment system (Dentsply-Maillefer, Ballaigues, Switzerland). During the retreatment procedure, in group 1 Resosolv (Pierre Rolland, Merignac, France) was used; in group 2 eucalyptol was used, in group 3 Endosolv E (Septodont, Paris, France) was used and in group 4 no solvent was used. The times required for retreatments and radiographycal evaluation after retreatment were recorded. Results: All root canals showed filling material remnants and group 1 with specific solvent for AH Plus recorded the shortest time. Conclusions: Although it is not possible to eliminate the entire filling material on the canal walls, the duration of retreatment was reduced by the use of a solvent specific to the sealer compared with a gutta-percha solvent or no solvent.

Effect of Instrument Design and Access Outlines on the Removal of Root Canal Obturation Materials in Oval-shaped Canals

IntroductionThe aim of this study was to compare the effectiveness of TRUShape (TS) instruments with ProFile Vortex Blue (VB) instruments for the removal of obturation materials during retreatment of single-canal mandibular premolars performed through 2 access outlines. MethodsInitial root canal treatment was completed through a contracted endodontic cavity (CEC) design. Canals were instrumented to an F2 ProTaper instrument, obturated with warm lateral condensation of gutta-percha with AH Plus sealer, and allowed to set for 30 days at 37°C and 100% humidity. For retreatment, specimens were divided into 2 groups (n = 24) on the basis of access outline, CEC or traditional endodontic cavity (TEC). Retreatment was initiated by using ProTaper Retreatment instruments (D1–D3). Specimens were then stratified, further divided (n = 12), and reinstrumented up to TS 40 .06v or 40 .06 VB. Irrigation was performed by using 8.25% NaOCl and QMix 2in1. Retreatment time was recorded. Teeth were sectioned and photographed, and the percentage of remaining obturation materials was measured. Data were analyzed with Kruskal-Wallis analysis of variance for two-factor tests (α < 0.05). ResultsThe interaction between access design and instrument type showed that the combination of CEC-VB presented significantly higher amounts of remaining obturation materials on the canal surface when compared with TEC-VB, CEC-TS, and TEC-TS (P ≤ .05). None of these other combinations were different from each other (P > .05). Significantly more time was required for retreatment with CEC-TS (27.68 ± 1.4 minutes) than the other groups (P < .05). ConclusionsNeither retreatment protocol was able to completely eliminate all obturation materials from the root canal surface of mandibular premolars. However, in the presence of a CEC access design, using TS instruments removed more obturating material in single-rooted, oval-shaped canals.

Efficacy of ProTaper and Mtwo Retreatment Files in Removal of Gutta-percha and GuttaFlow from Root Canals.

Introduction: The aim of this in vitro study was to compare the efficacy of ProTaper retreatment (ProTaper R) and Mtwo retreatment (Mtwo R) files in removing gutta-percha and GuttaFlow from endodontically treated straight root canals. Methods and Materials:The root canals of 60 human mandibular single-rooted premolars were prepared and randomly divided into two groups (n=30). In groups A and B the root canals were obturated using lateral condensation of gutta-percha plus AH 26 and GuttaFlow, respectively. The canal orifices were temporarily sealed and the roots were incubated for 3 months at 37ºC and 100% humidity. Primary cone-beam computed tomography (CBCT) images were taken after incubation period. The specimens in each group were randomly divided into two subgroups (n=15). ProTaper R files (D1, D2, and D3) were used in groups A1 and B1 while Mtwo R files (25/0.05 and 15/0.05) were used in groups A2 and B2. The time required to extirpate the root filling was also recorded. After retreatment, another CBCT scan was taken at the same position. The volume of remaining filling materials inside the canals was calculated before and after retreatment. The data was analyzed using the two-way ANOVA and independent t-test. Results:The remaining filling materials in the canals treated with ProTaper were less than Mtwo. The remaining volume of GuttaFlow was less than gutta-percha regardless of the system applied. Mtwo R files removed root fillings faster than ProTaper R. Conclusion:ProTaper R removed filling material more efficiently compared to Mtwo R which required less time to remove root filling material.

Root Canal Treatment of Three - Rooted Maxillary Second Premolar Done by Undergraduate Dental Student - A Case Report

The possibility of a three rooted maxillary second premolar is extremely rare; diagnosis and treatment of such cases is challenging especially for undergraduate dental students. The aim of this report is to present a root canal treatment of a very rare case of a three rooted upper maxillary second premolar tooth done by an undergraduate dental student. The tooth was diagnosed as acute irreversible pulpitis. Visually the tooth morphologically looked as a normal premolar but radiographically revealed anatomical variations of three roots. Access cavity was opened carefully; three canals were detected, negotiated, biomechanically prepared and obturated by cold gutta percha lateral condensation technique. The tooth is now completely asymptomatic for almost five months and will be both clinically and radiographicaly monitored bimonthly. A correct radiographic and clinical examination based on knowledge of anatomical variation of this Case Report Awooda et al.; BJMMR, 8(6): 558-563, 2015; Article no.BJMMR.2015.480 559 tooth is necessary for successful treatment and better prognosis. Under direct supervision, undergraduate clinical students can perform root canal treatment of difficult cases.

Effect of coronal cement base and its thickness on the fracture resistance of endodontically treated teeth

Objective: To compare the fracture resistance of endodontically treated teeth with mesiodistocclusal (MOD) cavities restored with only composite resin, 3 mm glass-ionomer cement (GIC) base + composite resin, and 5 mm GIC base + composite resin. Materials and Methods: Fifty extracted intact mandibular molars were randomly divided into five groups each including 10 teeth. Group 1: No cavity preparation or endodontic treatment was applied (intact teeth). Group 2-5: Root canals were prepared with step-back technique and filled lateral condensation of gutta-percha and sealer. Group 2: No coronal restoration was achieved. Group 3: Teeth were coronally restored with only composite resin. Group 4: Coronal restorations were performed with composite resin following 3 mm GIC base placement. Group 5: Composite resin placed over 5 mm GIC base. After finishing and polishing, all specimens were kept in an incubator at 37°C in 100% humidity for 24 h and fracture resistance was tested with a Universal Testing Machine. Mean force load for each sample was recorded in Newtons (N). Results were statistically analyzed with one-way analysis of variance (ANOVA) and post-hoc Tukey's tests. Results: The mean force required to fracture each sample was as follows: Group 1: 2,745.3; Group 2: 325.9; Group 3: 1,958.1; Group 4: 1,756.3; and Group 5: 1,889.1. Fracture resistance of intact teeth (Group 1) was significantly higher than all other groups. Fracture resistance of teeth in Group 2 (not coronally restored) was significantly lower than all other groups. Fracture resistance values of other three experimental groups (Groups 3, 4, and 5) were not significantly different from each other. Conclusion: Placing a GIC base and its thickness did not significantly affect the fracture resistance compared with composite resin alone.