ProTaper Universal Retreatment System Research Articles

ProTaper universal retreatment retreatment potential in oval-shaped canals filled with different obturation techniques-A micro-computed tomography study.

The objective of this in vitro micro-computed tomography investigation is to assess the efficacy of the ProTaper Universal Retreatment System in retreating oval-shaped root canals filled with three obturation procedures. Thirty-six lower incisors with a single oval root canal were prepared using XP-Endo Shaper up to size 30/0.04, and allocated into three equal groups based on the filling technique: Group 1: Warm vertical condensation technique; Group 2: GuttaCore obturators; Group 3: Cold lateral condensation technique. All samples were further retreated using the ProTaper Universal Retreatment system. Micro-CT analysis was performed before and after the retreatment procedure. Statistical analysis was performed with a significance level of 0.05. Data analysis was conducted using the Kolmogorov-Smirnov and Kruskal-Wallis H tests. The best performance of the files was achieved when the removal of the filling in the entire canal was considered. However, this outcome was not statistically significant when compared with the other observed root canal levels. The retreatment procedure could not ensure thorough cleanliness of the canal walls from filling remnants, regardless of the obturation technique and observational level. The ProTaper Universal Retreatment system used for the removal of gutta-percha and sealer in oval-shaped root canals demonstrated equal effectiveness, regardless of the obturation technique used.

Efficacy of different Er:YAG laser-activated photoacoustic streaming modes compared to passive ultrasonic irrigation in the retreatment of curved root canals.

To evaluate the efficacy of passive ultrasonic irrigation (PUI) and super short pulse (SSP) and shock wave-enhanced emission photoacoustic streaming (SWEEPS) modes of Er:YAG laser-activated irrigation (LAI) with two different laser tips, in removing filling remnants after conventional retreatment in severely curved root canals. The study sample consisted of 40 extracted molars with curved mesiobuccal root canals. The canals were instrumented with ProTaper Next and filled with an epoxy resin-based sealer and gutta-percha using continuous wave vertical compaction and warm injection back-filling. After retreatment with ProTaper Universal Retreatment system and sodium hypochlorite (NaOCl), all samples were randomly divided into four groups (n = 10) according to the final irrigation technique: PUI, LAI/SSP, SWEEPS/flat-tip, and SWEEPS/radial-tip, using 6mL of 3% NaOCl for an activation time of 3 × 30s. The samples were subjected to micro-CT scans after root canal filling, retreatment, and final irrigation. The filling material volume and percentage reduction were calculated. All tested irrigation techniques were successful in the elimination of the filling remnants after the retreatment (p < 0.001). The LAI/SSP group showed a higher reduction rate than the SWEEPS/flat-tip group (p = 0.032). No significant differences were found between the other groups (p > 0.05). All tested techniques improved the removal of filling material during retreatment in curved canals. LAI/SSP showed slightly better results than other techniques. The study highlights the need for additional activated irrigation after the retreatment of curved root canals. The choice between PUI and LAI is not decisive for success.

Comparison of the Time Required by Six Different Retreatment Techniques for Retrieval of Gutta-Percha: An In Vitro Study

Abstract Objective A retreatment is a conservative approach than periapical surgery in case of failed root canal treatment. Retreatment techniques that are efficient and faster should be the main concern to treat endodontic failure. This study aimed to compare the time required by various hand and rotary retreatment systems for the retrieval of gutta-percha (GP) from root canals. Materials and Methods A total of 120 extracted single-rooted premolar teeth with straight canals were chosen. Biomechanical preparation was completed using the Step-Back approach keeping the master apical file size 35. Then, teeth were down-packed and back-filled with System B device, along with AH Plus sealer. The teeth were categorized into six groups (n = 20) at random as per techniques applied for retrieval of GP: group I hand instrumentation (Hedstrom files and Gates-Glidden drills); group II ProTaper Universal Retreatment (PTUR) system; group III Mtwo Retreatment (Mtwo R) system; group IV D-RaCe; group V R-Endo; and group VI Mani Gutta Percha Remover (NRT-GPR). A chronometer was used to measure the time required for retrieval of GP. Data were examined by comparative evaluation of one-way analysis of variance and chi-square test. Results Among all the retreatment techniques used, D-RaCe was faster in GP retrieval than other groups. NRT-GPR system also took less time than other groups except for the D-RaCe system. The Mtwo R system was the slowest among all groups. Conclusion D-RaCe retreatment instruments required extensively less time for retrieval of GP than other groups (p &lt; 0.001).

Comparative evaluation for removal of gutta-percha and bio-ceramic sealers from oval root canals with reciprocating and rotary retreatment file systems

Context: Residual filling material can impair the prognosis in endodontic retreatment cases. A variety of file systems have been used in both rotary and reciprocating motion. Aims: To evaluate and compare the ability of ProTaper Universal Retreatment systems, GPR Mani Retreatment systems and, V Blue Reciproc systems in removal of gutta percha and bioceramicsealer from oval root canals using micro-computed tomography. Materials and Methods: Sixty extracted human mandibular premolar with oval canals standardised with cone beam computed tomography(CBCT). Following preparation with ProTaper Next files and obturation with gutta-percha and I Root SP sealer all specimens were randomly assigned to three groups ProTaper Universal retreatment system (PTUR), GPR Mani Retreatment system and V-Blue files, (n=20). Quality of obturation was confirmed with CBCT. After 1 month, retreatment was carried out and the percentage of remaining obturating material was evaluated before and after retreatment through micro-CT imaging. Two sample means and Kolmogorov-Smirnov test were used to analyse data. Results: The V-Blue files removed 97.27% of residual filling material whereas PTUR and GPR Maniremoved 85% and 79.33% respectivelyand the difference between V-Blue and other two files tested was statistically significant (P&lt; 0.05).

The effectiveness of rotary and reciprocating techniques in curved root canals retreatment: a micro-CT analysis.

Introduction: Different NiTi rotary systems have been developed to improve efficiency and retreatment success rates. Aim: To evaluate the Protaper Universal retreatment system and WaveOne instrument in removing the filling material from curved canals during retreatment. Materials and Methods: Thirty mesial root canals of extracted human mandibular molar teeth were randomly allocated into 2 groups (n=15). In the PT group, retreatment was performed with ProTaper Universal Retreatment according to the manufacturer’s instructions. In the WO group, was used WaveOne Primary. ProTaper Universal F2 and F3 were used to achieve the apical diameter in both groups. The samples were scanned by micro-computed tomography pre and postoperatively to evaluate the filling material remaining. The percentage of material filling was compared between groups using Student’s T test and in the same group among thirds was compared using Kruskal-Wallis followed by Dunn’s post hoc test. Results: The filling material remaining was not statistically different between the groups (p≥0.05). The apical third presented a greater amount of remaining filling material when compared with the cervical third for both groups (p&lt;0.05). Conclusion: Rotary and reciprocating techniques can effectively, but not completely, remove the filling materials from the root canal system. The apical third presented a more significant amount of remaining filling material.

The effect of experimental conditions in root dentin microcracks detection by micro-computed tomography

The aim of the study was to assess the effect of different experimental conditions on registration of microcracks by means of micro-computed tomography. Twenty roots of permanent lower incisors were instrumented with SAF system, filled with a single-cone technique and retreated with the Pro Taper Universal Retreatment system. Each sample was measured in dry, water, and moist conditions. The dry scanning was done after drying of the roots for a period of 4 h in ambient conditions followed by a second observation in wet environment after 48 h of rehydrating in distilled water. A time scan was performed to measure the dentin shrinkage while drying the samples in the tomograph’s device compartment. All roots underwent complex inhomogeneous shrinkage and deformation due to the internal stress upon dehydration. This deformation opened the existing cracks to an extent above the current resolution of today’s laboratory computed tomography scanners. Contrary, rehydration of the dentin reversed the deformation thus closing some of the cracks below the computed tomography resolution making them undetectable. The first dehydration of dentin may be a source of cracks initiation itself.

Efficacy of Rotary Retreatment Techniques Assisted with Passive Ultrasonic Activation of Resin Solvent in Removal of Gutta-percha with Epoxy Resin and MTA Based Root Canal Sealers: An In-vitro Study

Introduction: Endodontic retreatment is indicated in cases of failed primary endodontic treatment. The main goal of retreatment is to establish conditions that will enable the healing of the periapical tissue. Aim: To evaluate the efficacy of rotary retreatment with the ProTaper Universal Retreatment system supplemented with passive ultrasonic activation of solvent in retreatment of singlerooted mandibular premolar teeth obturated with gutta-percha and two different root canal sealers (AH Plus and MTA Fillapex). Materials and Methods: This in-vitro study was conducted in the Department of Conservative Dentistry and Endodontics at Mahatma Gandhi Mission’s Dental College and Hospital, Navi Mumbai, Maharashtra, India, from January 2019 to April 2019. Total 66 freshly extracted human single rooted mandibular premolars were used in this study. Root canal preparation was done using ProTaper Next rotary files. Teeth were decoronated to get a uniform length of 18 mm and were divided into three retreatment groups based on the technique used for retreatment. Group I included rotary retreatment, Group II involved rotary retreatment with solvent and paper point wicking, and Group III involved rotary retreatment with passive ultrasonic activation of solvent and paper point wicking. Based on the sealer used for obturation, teeth in each group were further divided into two subgroups, subgroup A with AH Plus sealer and subgroup B with MTA Fillapex sealer. Teeth were stored in an incubator for 30 days to allow sealer to set after which sectioning of the specimens was done buccolingually for examination under the stereomicroscope and photographed. Statistical analysis was done by using parametric Analysis of Variance (ANOVA) followed by Post-hoc tests and Unpaired t-test. Results: No statistically significant difference in percentage area of residual root canal filling material noted between the group I and II and when obturated with gutta-percha and AH Plus sealer (subgroup A) as p-value=0.215. Whereas, it revealed a statistically significant difference between the group I, II, and III when obturated with gutta-percha and MTA Fillapex sealer (subgroup B) as p-value&lt;0.001. Conclusion: Passive ultrasonic activation of solvent after guttapercha removal using ProTaper Universal rotary files could improve the quality of endodontic retreatment.

Comparative Evaluation of Efficacy of Protaper Universal Retreatment System, R-Endo System and Hedstrom File in Gutta Percha Removal During Root Canal Retreatment- An In Vitro Study.

Background:The complete removal of residual filling materials from the root canal determines the success of root canal retreatment.Aim:To evaluate and correlate the efficacy of ProTaper retreatment system, R-Endo retreatment system, and Hedstrom file in the removal of gutta-percha and sealer from root canal during endodontic retreatment in addition to the period desired for the elimination of gutta-percha and sealer.Methodology:Thirty extracted premolars were prepared and filled by cold lateral compaction with gutta-percha and sealer. Retreatment was finished with ProTaper retreatment files, R-Endo files, Hedstrom files with Endosolv E as the solvent for 10 specimens each. Each half of the root was imaged using the image analyzer software Chroma allied to a stereomicroscope with 10× magnification via a charge-coupled device sensor. For statistical analysis, parametric one-way ANOVA test and Scheffe post hoc multiple range test were utilized at a significance level of P < 0.05.Results:There is no significant difference among the three groups at P < 0.0001 in removing filling material. However, the rotary files needed significantly less time for removing gutta-percha along with sealer than H-file (P < 0.0001).Conclusion:The gutta-percha and sealer were found in the root canal subsequent to all the retreatment techniques, especially in the apical third. Retreatment time was less only for the rotary system.

Efficiency of Supplementary Contemporary Single-file Systems in Removing Filling Remnants from Oval-shaped Canals: An In Vitro Study

This study investigated the performance of supplementary three single-file systems for eliminating root filling residue from oval-shaped canals utilizing cone-beam computed tomography (CBCT). Thirty single-rooted human mandibular premolars with oval-shaped canals were chosen. After decoronation and working length determination, ProTaper Universal (PTUR) rotary files were used to prepare canals up to F3. Irrigation was fulfilled by 2.5% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA), and lastly distilled water. By utilizing the lateral compaction technique, canals were filled by gutta-percha and Endosequence BC Sealer. The PTUR retreatment system (D1, D2, and D3) eliminated the primary filling material sequentially. Subsequently, specimens were categorized into three groups at random: group I: WaveOne Gold (WOG) primary file, group II: TruNatomy (TRN) medium file, and group III: XP-endo Finisher R (XPF-R). The volume of residual left from filling material was quantified utilizing CBCT imaging before and after the supplementary retreatment. Statistical analyses were done by one-way analysis of variance (ANOVA) and Tukey's test at a 5% significance level. The volume of removed root filling after using XPF-R was significantly higher than using WOG in all sections and TRN in the coronal third, while nonsignificantly higher than using TRN in the apical and middle. XPF-R as a supplementary technique revealed the highest percentage reduction of root filling material (73.13%) in comparison with the other systems (37.39% WOG and 44.16% TRN) in oval-shaped canals. Neither one of the methods and tools used to remove filling material from oval-shaped root canals is perfectly efficient. The performance of supplementary techniques using contemporary single-file systems improves the cleaning and reshaping of root canal space that permits a proper disinfection to optimize the outcome of retreatment option.

Comparative assessment of canal transportation, dentin loss, and remaining root filling material by different retreatment files – An In vitro cross-sectional study

Aim:The purpose of this study was to evaluate the centering ability, canal transportation and efficacy of re-treatment rotary and hand files in removing Gutta Percha from root canals using Cone Beam Computed Tomography(CBCT).Materials and Methods:Sixty extracted human maxillary anteriors were obturated and randomly divided into three groups. Root fillings were removed with ProTaper Universal retreatment system, R-Endo system, and Hedstrom files. CBCT scans were taken.Statistical Analysis and Results:The data were analyzed using the Statistical Package for the Social Sciences (SPSS 15.0, IBM). The mean and standard deviation among the groups was calculated by one-way analysis of variance, Kruskal–Wallis, and Mann– Whitney U-tests, and the comparison among the various groups was done by post hoc Tukey's test. A statistically significant amount of remaining root canal filling material and canal transportation was noted (P < 0.05).Conclusion:No system completely removed the root filling material from root canals. Manual instrumentation resulted in more dentin loss and canal transportation than rotary file system.

Comparison of full rotation and reciprocating movements in regaining apical patency during endodontic retreatment

This study aimed to compare the continuous rotation and reciprocating movements of rotary files in achieving apical patency in root canal retreatment. This in vitro, experimental study evaluated 64 extracted mandibular molars. The teeth were prepared up to F3 with ProTaper Universal and obturated using lateral compaction technique. The teeth were divided into four groups (n = 16) based on the mesiobuccal canal curvature (Schneider's method) and type of rotational movement. Groups 1 and 2 included straight canal teeth retreated with WaveOne Gold and ProTaper Universal Retreatment system, respectively. Groups 3 and 4 included teeth with moderately curved root canals retreated with WaveOne Gold and ProTaper Universal, respectively. Apical patency was ensured by observing the tip of a hand K-file at the apical foramen. Data were analyzed using the Fisher's exact test. P < 0.05 was considered statistically significant. Apical patency was successfully achieved in all 16 teeth in group 1 (100%) and 15 teeth in group 2 (93.75%). No significant difference was noted between continuous rotation and reciprocating movements in straight canals (P = 1.00). Apical patency was successfully achieved in 15 teeth in group 3 (93.75%) and 12 teeth in group 4 (75%). No significant difference was noted between continuous rotation and reciprocating movements in moderately curved canals either (P = 0.333). Both continuous rotation and reciprocating movements are equally effective in achieving apical patency in straight or moderately curved mesiobuccal canal of mandibular molars.

Effectiveness of Guttapercha/Bioceramic sealer removal during retreatment using different irrigation protocols

Objectives: The purpose of the study was to assess the amount of residual root canal filling materials (Guttapercha/Bioceramic sealer) after using different irrigation protocols. Methodology: FortyMandibular premolar teeth were mechanically instrumented using Protaper Next rotary system and obturated with guttapercha master cones (size 25, 0.06 taper) coated with Sure Seal bioceramic sealer (Sure Dent Corp., Gyeonggi-do, Korea). All specimens were incubated for 4 weeks then retreatment was performed using Protaper Universal retreatment system. The specimens were randomly divided into four equal groups (n=10) according to the final irrigation protocol as follow; Conventional needle irrigation, Endovac, UltraX, Passive ultrasonic irrigation. Roots were grooved buccolingualy into two halves. A digital camera connected to the stereomicroscope captured images to each half. The root canals were segmented into thirds (Apical, middle and coronal). Image-J softwarewas used to evaluate and measure the areas with the remaining filling material in each third. Data were analysed using One-way ANOVA followed by Tukey’s post hoc test for intergroup comparisons while One-way repeated measures ANOVA was used for intra group comparisons. Results: All groups showed residual filling material in the root canals. The amount of the residual filling materials was significantly reduced upon using passive ultrasonic irrigation (P<0.001). Conclusion: None of the irrigant activation methods was capable of completely removing the root canal filling material. Passive Ultrasonic irrigation enhanced the retreatment procedure of root canals previously obturated with gutta percha/bioceramic sealer.

Comparative evaluation of retreatability of bioceramic sealer (BioRoot RCS) and epoxy resin (AH Plus) sealer with two different retreatment files: An in vitro study.

Aim:The aim of the study was to evaluate and compare the retreatability of BioRoot RCS and AH Plus sealer with two different retreatment file systems using cone-beam computed tomography (CBCT) for assessing the filling remnants.Materials and Methods:A total of sixty mandibular premolars with single and oval root canals were prepared till size F3 and obturated with GP/AH Plus (Group 1) and GP/BioRoot RCS (Group 2). Canals were then retreated using two different retreatment file systems – ProTaper Universal Retreatment (PTUR) system and NeoEndo Retreatment system. The ability to re-establish working length (WL) and apical patency was recorded, and the percentage volume of residual filling material was evaluated using CBCT at the coronal, middle, and apical thirds. Data from the study were analyzed using one-way analysis of variance with Pearson's Chi-squared analysis and the Kruskal–Wallis test.Results:No statistically significant difference was found in the amount of residual sealer (AH Plus and BioRoot RCS) after retreatment throughout the whole study (P > 0.05) at various root canal levels. Furthermore, the BioRoot RCS group retreated with the PTUR system showed a higher frequency of failure in re-establishing WL and regaining apical patency than the other groups.Conclusion:Complete removal of root canal sealers could not be achieved regardless of the type of sealer used and the retreatment technique employed. Furthermore, in clinical settings, the retreatability of novel BioRoot RCS may be deemed feasible.

Retreatability of bioceramic and GuttaFlow bioseal root canal sealers using ProTaper universal system retreatment files: An Ex vivo study

Introduction: To evaluate the retreatability of Bioceramic and GuttaFlow Bioseal sealers using ProTaper Universal System Retreatment files aided by dental microscope analysis. Materials and Methods: Root canals of forty single-rooted human mandibular premolar teeth were prepared with ProTaper Next rotary system and obturated with single-cone obturation technique (n = 20 each) using EndoSequence Bioceramic root canal sealer (Group 1) and GuttaFlow Bioseal root canal sealer (Group 2). All specimens were retreated with ProTaper Universal Retreatment System files. The working time of retreatment procedure was calculated. Samples were sectioned, and the residual filling remnants were observed under dental operating microscope. Statistical analysis was performed using SPSS software. Results: The least total working time was observed in GuttaFlow Bioseal group (2.35 min). Overall, less residual filling materials was found in Bioceramic sealer group specimens in all root levels compared to GuttaFlow Bioseal group (P = 0.000, 0.022, and 0.000, respectively). Conclusion: The retreatment technique used was incapable of complete removal of filling material within root canal walls.

In Vitro Comparison of Gutta-Percha Removal Using XP Endo Finisher and ProTaper With or Without Organic Solvent by Scanning Electron Microscope

Introduction: Non-surgical endodontic retreatment is highly dependent on the removal of previous root filling material, bacteria and necrotic tissue. Various techniques and instruments have been used for endodontic retreatment. Recently, the XP-endo Finisher has been introduced in endodontic treatment to clean highly complex morphologies and difficult to reach areas. Aims: a) To compare the effectiveness of XP-endo Finisher and ProTaper universal retreatment system with or without organic solvent in removing gutta-percha. b) To compare the amount of apically extruded debris between the groups. Methods: 24-human- extracted, single-rooted teeth were divided into three groups of 8. The groups were classified as follows: Group I: using a ProTaper universal retreatment system with chloroform. Group II: using a ProTaper universal retreatment system without chloroform. Group III: using a ProTaper universal retreatment system followed by XP-endo Finisher without chloroform. The apically extruded debris was collected during the retreatment and weighted. The roots were split longitudinally. The degree of dentinal tubules patency was evaluated by scanning electron microscopy. Results: The most intensely clear dentinal tubules were observed in group III, followed by group II and group I, respectively. Group I resulted in a debris extrusion, significantly less, as compared with the other groups (P &lt; 0.05). While there was no notable difference between group II and group III (P &gt; 0.05). Conclusion: Under the conditions of the present study, out of all the retreatment techniques that were used, the XPendo Finisher was the most effective in the removal of the gutta-percha in cervical, middle and apical thirds. The use of solvent during retreatment can decrease the amount of the apically extruded debris.

A micro-computed tomographic evaluation of retreatability of BioRoot RCS in comparison with AH Plus.

This study compared the retreatability of filling material from canals filled with BioRoot RCS (Septodont, Saint-Maur-des-Fosses, France) and AH Plus (Dentsply DeTrey, Konstanz, Germany) combined with gutta-percha using micro-computed tomography for evaluation. Thirty-four mandibular premolars were divided into two groups according to the sealer used. Thirty days after obturation, canals were retreated with a ProTaper Universal retreatment system (Dentsply Maillefer, Ballaigues, Switzerland) followed by passive ultrasonic irrigation (PUI). The time taken for retreatment was recorded. The roots were scanned after obturation, after retreatment and after PUI. Data were analysed using the Mann-Whitney and Wilcoxon tests. Canals filled with BioRoot RCS exhibited significantly less remaining filling material than canals filled with AH Plus (P<0.05). The addition of PUI resulted in a significant decrease in the residual material in both groups (P<0.05). A significantly shorter retreatment time was reported for the AH Plus group than the BioRoot RCS group (P<0.05).

Evaluation of filling material remnants after basic preparation, apical enlargement and final irrigation in retreatment of severely curved root canals in extracted teeth.

To compare the retreatment ability of several rotary and reciprocating file systems in curved root canals of extracted teeth and to evaluate the influence of additional apical enlargement performed after a basic retreatment on the amount of remaining filling material. A total of 65 round curved root canals were used. The root canals were prepared with the ProTaper Next rotary system to size 25, .06 taper and filled with an epoxy resin-based sealer and gutta-percha using continuous wave vertical compaction and warm injection back-filling. The canals were randomly divided into four groups according to the retreatment system used: Group I. ProTaper Universal Retreatment system+ProTaper Gold (PTG) instrumentation system up to PTG F2; Group II. Reciproc Blue system up to the instrument RB25; Group III. Reciproc system up to the instrument R25; Group IV. Wave One Gold (WOG) system up to the instrument WOG25. After the basic retreatment, additional apical enlargement was performed in each group with an instrument that was one size larger: in Group I, II and III up to apical size 40, and in Group IV up to 35. The final irrigation protocol included the following: 15% ethylenediaminotetraacetic acid followed by NaOCl irrigation. The volume of filling material was measured using an industrial micro-CT four times: after root canal filling (Volume I), after basic retreatment with size 25 files (Volume II), after additional root canal enlargement with larger instruments (Volume III), and after the final irrigation protocol (Volume IV). The decrease in the amount of filling material after each retreatment protocol was analysed using a Kruskal-Wallis test. Intergroup analyses were performed with a Kruskal-Wallis test and between-group differences were further analysed with Mann-Whitney U test. There were no significant differences amongst the systems tested in the amount of remaining filling material, or the reduction rates after each phase of the retreatment procedures (P>0.05). Intragroup analysis indicated that the use of a larger final instrument removed significantly more filling material in all groups (P<0.001). The four tested instrumentation systems were equally effective in removing filling materials from curved root canals in extracted teeth. Additional apical enlargement with larger files improved the removal of filling remnants after basic retreatment.

In vitro comparative evaluation of efficiency of XP-endo shaper, XP-endo finisher, and XP-endo finisher-R files in terms of residual root filling material, preservation of root dentin, and time during retreatment procedures in oval canals - A cone-beam computed tomography analysis.

Background:In an oval-shaped canal, no single instrumentation systems were effective in absolute removing obturation.Aim:The aim of the study was to evaluate the performance of ProTaper Universal Retreatment (PTUR) system, XP-endo Shaper (XPS), XP-endo Finisher (XPF), and XP-endo Finisher-R (XPF-R) in removing root-canal filling material and preservation of sound dentin during retreatment procedure.Methodology:Root-canal preparation was performed on 60 mandibular premolars with oval-shaped canals using the ProTaper Gold file system. Preobturation scans were performed to measure canal volume of the canal and recorded. Obturation was performed and the samples were randomly assigned into four groups according to the retreatment protocol used (n = 15): H-file, PTUR files, PTUR followed by XPF file, and XPS supplemented with XPF-R file. After retreatment, the specimens were re-scanned and volumetric analysis of remaining root filling material, volume of the canal space were measured using EZ-3Di Software Version 5.0.0.2. All the data were subjected to one-way ANOVA and post hoc Tukey's test with a significance of 5%.Results:XPS + XPF-R showed promising results in the removal of obturating material and preservation of root dentin than any other group. The difference is statistically significant.Conclusion:XPS + XPF-R removed gutta-percha more significantly without sacrificing the sound dentin along with instrumentation.

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.

ProTaper retreatment system versus balanced force technique for apical extrusion and gutta-percha removal

Introduction: The aim was to compare root canal wall cleanliness, amounts of apically extruded debris and irrigant during retreatment using the ProTaper Universal Retreatment (PT) system or balanced force technique (BFT).&#x0D; Materials and Methods: Root canals of extracted mandibular premolar teeth (n=44) were endodontically prepared and obturated, then the teeth were divided into two groups: BFT and PT. Apically extruded material was collected into preweighed Eppendorf tubes using the Myers and Montgomery method. The root halves were photographed under a stereomicroscope. Area of the remnant filling material (coronal, middle, apical thirds and total canal surface) was measured by software. Data were analyzed by Mann-Whitney U test.&#x0D; Results: The BFT and PT system provided similar degrees of canal wall cleanliness (p &gt; 0.05) and amounts of extruded irrigant (p&gt;0.05). The PT system caused less debris extrusion (p&lt;0.05).&#x0D; Conclusions: Although the BFT was shown to cause less apical extrusion in primary root canal treatment compared to other manual instrumentation techniques, in the present study, BFT caused more debris extrusion than the PT group.&#x0D; &#x0D; How to cite this article: Sarıçam E, Altunkaynak B, Kayaoğlu G. ProTaper Retreatment system versus balanced force technique for apical extrusion and gutta-percha removal. Int Dent Res 2019;9(2):63-8.&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.