Quality of Root Canal Fillings and Procedural Errors for In Vivo Studies Prepared in Different Clinical Settings and with Rotary Systems: A Systematic Review.

BACKGROUND This systematic review of the literature aimed to identify published studies and evaluate them on the quality of root canal fillings (RCF) and procedural errors with rotary systems for in vivo studies prepared for different clinical settings. MATERIAL AND METHODS A full literature exploration was conducted in Clarivate Analytics' Web of Science, Elsevier's Scopus, Embase, and PubMed for studies published between January 2020 and March 2024. A manual search was also performed by reviewing the references of selected papers. The following keywords were used: quality of root canal filling(s) OR quality of root canal obturation, root canal obturation OR endodontic treatment, clinical setting (academic, private, governmental), AND/OR procedural errors and rotary instrumentation. RESULTS Sixteen clinical studies were included in this review. The acceptance percentages for obturation length, density, and taper were 76.3%, 74.7%, and 82.5%, respectively, indicating significantly high, good ratios. The overall RCF recorded showed that 68.2% of root canal obturations were considered acceptable. Acceptable rates remained higher than unacceptable rates in academic, hospital, and private settings, and percentages ranged from 65.2% to 93.0%. Only 5 studies reported procedural errors, namely, ledge formation, separated instruments, apical perforation, transportation, lateral perforation, and root/foramen perforation. CONCLUSIONS Using rotary instruments for different root canal treatment steps as instrumentation and obturations is highly recommended. Among different clinical setting and practice, these instruments resulted in a good and acceptable RCF, overall quality performed by those instruments, and few procedural errors.

CTZ and Calcium Hydroxide Pastes Did Not Cause Hepatic and Renal Alterations in Mice

ABSTRACT Objective: To evaluate the possible renal and hepatic alteration by root canal filling pastes in mice. Material and Methods: Fifty-four mice were divided into nine groups and received one polyethylene tube implant containing two filling pastes (CTZ or calcium hydroxide pastes). Empty polyethylene tubes were used as a negative control. All tubes were implanted subcutaneously in the back of the mice. After time intervals of 7, 21, and 63 days, 1.5 mL of blood was collected by cardiac puncture, and serum samples were used for serological testing. Urea, creatinine, aspartate transferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT) were evaluated. Data were analyzed by 2-way ANOVA (p<0.05). Results: When comparing CTZ and calcium hydroxide pastes and empty tubes and experimental time intervals, no significant differences in the results were found for any of the biochemical parameters analyzed (p>0.05). No differences were observed in the interactions (material*experimental time intervals) and the biochemical parameters analyzed (p>0.05). Conclusion: CTZ and calcium hydroxide pastes did not cause hepatic and renal alterations in mice, demonstrating the pastes' safety.

Continuous Wave of Condensation Improves the Filling of Curved Canals: a Micro-CT Study / La condensación de onda contínua mejora el selle de canales curvos: un estudio de micro-CT

Abstract The aim of this study was to compare the filling capacity in curved root canal using a new continuous wave of condensation technique (Termo Pack II, Easy Dental Equipments, Brazil) or lateral compaction. The percentage of voids in the filling of mesial root canals of mandibular molars was assessed by micro-computed tomography (micro-CT). Mesial root canals (n=24) of mandibular molars with a degree of curvature between 20° and 40° were prepared using rotary system (ProDesign Logic, Easy, Brazil) up to #35, .05 taper. The root canals were filled by using the continuous wave of condensation system or lateral compaction and AH Plus sealer (n=12). Scanning at 9 µm was performed after preparation and after filling by using micro-CT SkyScan 1176. The volumetric percentage of filling material and voids (total length and in each root canal third) were calculated. Data were analyzed using ANOVA/ Tukey and Student's t tests (α=0.05). Before the filling techniques, the root canals volume after preparation was similar (p>0.05). The root canals filled by the continuous wave of condensation technique presented the lowest percentage of voids, and the greatest percentage of filling material in total length and thirds (cervical, middle and apical) (p<0.05). Both techniques were not able of completely filling the root canals. The continuous wave of condensation technique Termo Pack II promoted better root canal filling in curved root canals, when compared with lateral compaction.

Resumen El objetivo de este estudio fue comparar la capacidad de obturación en conductos radiculares curvos utilizando una nueva técnica de condensación de onda continua (Termo Pack II, Easy Dental Equipments, Brasil) vs compactación lateral. El porcentaje de brechas en la obturación de los conductos radiculares mesiales de los molares mandibulares se evaluó mediante microtomografía computarizada (micro-CT). Se prepararon conductos radiculares mesiales (n=24) de molares mandibulares con un grado de curvatura entre 20° y 40° utilizando un sistema rotatorio (ProDesign Logic, Easy, Brasil) al #35, conicidad 0,05. Los conductos radiculares se obturaron utilizando un sistema de condensación de onda contínua o compactación lateral y cemento AH Plus (n=12). Se realizó un escaneo de 9 µm después de la preparación y después de la obturación usando el micro-CT SkyScan 1176. Se calculó el porcentaje volumétrico de material de obturación y vacíos (longitud total y en cada tercio del conducto radicular). Los datos se analizaron utilizando las pruebas ANOVA/Tukey y t de Student (α=0,05). Antes de las técnicas de obturación, el volumen de los conductos radiculares después de la preparación fue similar (p>0,05). Los conductos radiculares obturados con la técnica de condensación por onda contínua presentaron el menor porcentaje de vacíos y el mayor porcentaje de material de obturación en longitud total y en tercios (cervical, medio y apical) (p<0,05). Ambas técnicas no fueron capaces de llenar completamente los conductos radiculares. La técnica de condensación de onda contínua Termo Pack II promovió un mejor relleno del conducto radicular en conductos radiculares curvos en comparación con la compactación lateral.

Introduction of nickel titanium rotary instruments to undergraduate students: afour-yearclinical experience / Introdução de instrumentos rotários de níquel titânio para alunos de graduação: quatro anos de experiência clínica

Many studies address the quality of root canal treatments, but few refer to endodontics usingrotatory techniques performed by noviceoperators. This study evaluatedthe performance of undergraduates in their first contact with rotary root canal instrumentation concerningthe findings of the final periapical radiograph, and thepostendodontic treatment pain.A longitudinal observational studywas performed on periapical radiographs of 491teethfrom 450 patientssubmitted toroot canal treatmentby undergraduate students from 2015 to 2018. The analysis of the length of root canal filling followed the criteria: (i) acceptable, ifperiapical radiograph presentsroot filling ending 0 -1 mm short of radiographic apex; (ii) over, if periapical radiograph presentsroot filling ending beyond the radiographic apex; and (iii) under, ifperiapical radiograph presentsroot filling ending > 1 mm short of radiographic apex. Evaluation of postendodontic treatment painwas categorized into either absence or presenceof pain. Adequate length root canal filling was observed in 65.9% of the cases (324 teeth). Periapical lesions presenceand dimensions did not interfere to the obturation quality.Statistical relation was found between the pulp condition and postendodontic treatment pain. Thepresence of pain was observed in 4.7% of the vital teeth and 0.3% of non-vital teeth. The presence of periapical lesion did not influence postoperative pain.AdequatelengthrootcanalfillingwasobservedinmostcasesandNitTi rotary instrumentation hadapplicability in undergraduate programs, even with novice operators. Besides that, pulp condition had an effect on post endodontic pain (AU).

Muitos estudos abordam a qualidade dos tratamentos de canal radicular, mas poucos se referem à endodontia por meio de técnicas rotatórias realizada por operadores novatos. Este estudo avaliou o desempenho de graduandos no primeiro contato com a instrumentação endodôntica em relação aos achados da radiografia periapical final e à dor pós-tratamento endodôntico. Um estudo observacional longitudinal foi realizado em radiografias periapicais de 491 dentes de 450pacientes submetidos a tratamento endodôntico por estudantes de graduação no período de 2015 a 2018. A análise do comprimento da obturação de canais radiculares obedeceu aos critérios: (i) aceitável, se a radiografia periapical apresentasse término de obturação 0 -1 mm aquém do ápice radiográfico; (ii) acima, se a radiografia periapical apresentasse obturação que termina além do ápice radiográfico; e (iii) abaixo, se a radiografia periapicalapresentasse obturação, terminando > 1 mm aquém do ápice radiográfico. A avaliação da dor pós-operatória foi categorizada em ausência ou presença de dor. A obturação de canais radiculares de comprimento adequado foi observada em 65,9% dos casos (324 dentes). A presença e as dimensões das lesões periapicais não interferiram na qualidade da obturação. Foi encontrada relação estatística entre a condição pulpar e a dor pós-tratamento endodôntico. Presença de dor foi observada em 4,7% dos dentes vitais e 0,3% dos não vitais. A presença de lesão periapical não influenciou na dor pós-operatória. O comprimento de trabalho adequado foi observado na maioria dos casos e a instrumentação rotatória NitTi teve aplicabilidade em programas de graduação, mesmo com operadores iniciantes. Além disso, a condição pulpar afetou a dor pós-operatória (AU).

Análisis Elemental de las Propiedades Morfológicas, Físicas y Químicas de Dos Instrumentos Rotatorios Protaper Universal / Elemental Analysis of the Morphological, Physical and Chemical Properties of Two Protaper Universal Rotary Instruments

Los instrumentos rotatorios utilizados en el tratamiento de conductos dentales necesitan cumplir con ciertas características físicas que le confieran un uso correcto, adecuado y seguro para su uso clínico. En el mercado comercial existen una serie de instrumentos importados que dejan en duda la autenticidad de estos debido a sus bajos costos. En este estudio evaluamos física, química y morfológicamente dos kits de instrumentos rotatorios Protaper universal (Dentsply) mediante análisis de MEB, EDX, microdureza y EDS. Uno de los kits (grupo 1) se adquirió directamente de la casa comercial y otro kit importado que a simple vista no parecía cumplir con los estándares de calidad de un correcto empaquetado (grupo 2). En el análisis de MEB se observaron características morfológicas muy diferentes entre ambos kits, el grupo 2 presentó diversas irregularidades en la superficie de las limas, sin embargo, en el EDS no se encontró diferencia alguna. En cuanto al análisis de microdureza se observó una estadística estadísticamente significativa y en el EDS se observaron mayores picos de intensidad en cuanto a la aleación de Ni-Ti en el grupo 2. Estos resultados sugieren que existen instrumentos rotatorios importados que a pesar de su bajo costo pueden presentar ciertas características muy similares a los kits auténticos, sin embargo, física y químicamente pueden resultar en un riesgo para su uso clínico debido a la diferencia entre estos.

Rotatory files are instruments used in the treatment of dental canals roots. These instruments need to comply with certain physical characteristics for a correct, adequate and safe use for clinical use. In the commercial market there are a series of imported instruments that cast doubt on their authenticity due to their low costs. In this study we physically, chemically and morphologically evaluated two Protaper universal rotary instrument kits (Dentsply) using SEM, EDX, microhardness and EDS analysis. One of the kits (group 1) was purchased directly from the commercial house and another imported kit that a simple view did not seem to meet the quality standards of a correct packaging (group 2). In the SEM analysis, very different morphological characteristics were observed between both kits, group 2 presented various irregularities on the surface of the files, however, no difference was found in the EDS. Regarding the microhardness analysis, a statistically significant statistic was observed and in the EDS, higher intensity peaks were observed in terms of the Ni-Ti alloy in group 2. These results suggest that there are imported rotary instruments that despite their low cost can present characteristics very similar to authentic kits, however, physically and chemically they can result in a risk for their clinical use due to the difference between them.

Evaluation of apical transportation and apical root sealing in root canals prepared with mtwo rotary system with and without apical enlargement ­ an in vitro study

The aim of this study was to evaluate apical transportation and apical root canal sealing after root canal filling in human teeth prepared with MTwo® Rotary System with and without apical foramen enlargement. Twenty mandibular premolars were divided into two groups (n=10). Group 1 had root canals prepared 1mm beyond the apical foramen. Group 2 had root canals prepared 1mm below the root canal length. After chemo-mechanical preparation, samples were submitted to scanning electronic microscopy. Apical foramen images had 75x magnification at standardized positions, allowing measurements from the apical foramen area before and after root canal preparation, and after root canal filling. Apical foramen shape and apical transportation, as well as its level of circumferential filling after root canal preparation were accessed using the Image Subtraction System. Scanning electronic microscopy analysis demonstrated that samples of Group 1 showed larger foraminal diameter than samples of Group 2 (p<0.05). Apical foramen transportation was statistically different between Groups 1 and 2 (p=0.0108). Furthermore, the apical foramen sealing also differed statistically between groups 1 and 2 (p=0.0007) and 100% of samples of Group 1 showed apical root canal sealing. Apical root canal sealing was more effective when the root canal was prepared with apical foramen enlargement, even when the apical transportation was detected.

Qualitative Analysis of Root Canal Treatments performed by Undergraduate Students: A Retrospective Study

ABSTRACT Objective: Toanalyze the technical quality of endodontic treatment carried out at the undergraduate dental clinics. Material and Methods: Random radiographic records of 92 patients' were selected who received endodontic treatment by the undergraduate students from June 2018 to July 2019. The quality of root canal filling was determined in relation to the adequate density, length, and taper. Statistical analysis was performed by using GraphPad (Prism 5), and to determine the association between different variables Chi-square test was used. Results: Adequate technical quality of canal obturation conducted by the undergraduate students was found in less than 65% of the cases. The frequency of adequate root canal taper was significantly greater in maxillary teeth (75%) as compared to mandibular teeth (33%); however, adequacy of acceptable density was found more in maxillary teeth (62%) as compared to mandibular teeth (55%).A statistically significant difference was seen in the quality of root canal fillings between anterior and posterior teeth (p=0.001). Conclusion: The root canal therapy performed by undergraduate students was less than optimum in terms of technical quality. Hence, it is suggested that the endodontic training courses delivered at pre-clinical and clinical levelsfor undergraduate students must be thoroughly revised.

Success Rate of Contemporary Regenerative Endodontic Therapy and the Expected Outcomes of the Endodontic Microsurgery: A Systematic Review and Meta-Analysis

ABSTRACT Objective: To examine the level of the accumulating success of the modern Resin-Based Endodontic Surgery (RES) and comparison with Endodontic Microsurgery (EMS) and finally offer a replacement at the predicted final results of EMS. Material and Methods: MEDLINE, PubMed, Cochrane Library, Embase, ISI, Google Scholar have been utilized as electronic databases for systematic literature until 2019. Therefore, Endnote X9, which can be provided in the market, has been applied to manage the electronic titles. Searches have been made with keywords "Endodontic Microsurgery OR EMS", "Resin-Based Endodontic Surgery OR RES", "Regenerative Endodontic Therapy", "Root-End Filling", "Root-End Surgery", "Periapical Surgery" and "Endodontics". Thus, this systematic review has been conducted concerningthe basic investigation of the PRISMA Statement-Preferred Reporting Items designed for the Meta-analyses and Systematic Reviews. Results: A total of RES =19 and EMS =31 with potential pertinent abstracts and topics were discovered in manual and electronic searches. Then, three articles for RES and four studies for EMS publications satisfied our inclusion criteria necessary for systematically reviewing the studies. The analysis showed the success rate for EMS as equal to 1.16 times the probability of the success rate for RES. Conclusion: Micro-surgical procedures superiorly achieved the predictable high success rate for the Root-end surgery compared to conventional methods.

Evaluation of the Effect of the Intensity and Occurrence of Postoperative Pain of Resin-Based and Bioceramic Root Canal Sealers: A Systematic Review and Meta-Analysis of Randomized Controlled Trial Studies

ABSTRACT Objective: To evaluate resin- and bioceramic root canal sealers affect postoperative intensity and pain occurrence. Material and Methods: From the electronic databases, PubMed, Cochrane Library, Embase, ISI have been used to perform systematic literature until September 2020. Electronic titles were managed using the Endnote X8 software. They performed searches with mesh terms. Two reviewers blindly and independently extracted data from studies that included data for data extraction. Results: A total of 186 potentially relevant titles and abstracts were found. Finally, four studies were included. Pain score was (RR = -0.20; 95% CI -1.09-0.68; p= 0.65). This result showed no statistically significant difference for the resin-based and bioceramic root canal sealers after 24 hours between the VAS scores. Conclusion: Postoperative pain was low in Patients requiring root canal retreatment and obturated with resin-based or bioceramic-based sealers without extrusion beyond the apex. No differences were observed between postoperative pain in resin-based and bioceramic root canal sealers 24 and 48 hours postoperatively.

Tratamiento regenerativo de lesión interproximal consecuente a fractura del tercio medio en diente permanente joven / Regenerative treatment of interproximal lesion following middle third fracture in a young permanent tooth

Se presenta un caso clínico de fractura radicular del tercio medio, de pieza 2.1 con desplazamiento de los cabos de fractura. Es tratado con un novedoso procedimiento terapéutico, mediante la utilización de un biomaterial de tercera generación osteoconductor, osteogénico y osteoinductor. Se obtiene la reparación del tejido conectivo interproximal y la formación de tejido calcificado (AU)

We present a clinical case of root fracture of the middle third, piece 2.1 with displacement of the fracture ends. It is treated with a novel therapeutic procedure, using a thirdgeneration osteoconductive, osteogenic and osteoinductive biomaterial. Interproximal connective tissue repair and calcified tissue formation are obtained (AU)

Antibacterial and Solubility Analysis of Experimental Phytotherapeutic Paste for Endodontic Treatment of Primary Teeth

ABSTRACT Objective: To evaluate the antibacterial effect and the solubility of experimental root canal filling pastes containing the phytoconstituents terpineol and cinnamaldehyde. Material and Methods: Minimum Inhibitory Concentration (MIC) of each phytoconstituent was determined against Enterococcus faecalis. Five groups of antibiotic pastes based on zinc oxide were obtained by mixing: only terpineol, only cinnamaldehyde, terpineol and cinnamaldehyde combined, chlorhexidine (antibiotic control), and CTZ paste (control paste). Antibacterial activity was analyzed through direct contact test within 24 and 72 hours. Solubility was evaluated by spectrophotometry within 48 and 144 hours. Antibacterial activity data were analyzed descriptively, and solubility data was analyzed using ANOVA and Tukey tests (p<0.05). Results: The MIC obtained for terpineol and cinnamaldehyde were, respectively, 2000 µg/mL and 500 µg/mL. After 24h, only the terpineol paste did not inhibit E. faecalis growth. After 72h, all groups inhibited E. faecalis growth. After 48h, the highest solubility was verified in the terpineol paste (p<0.05), and no differences were detected among other groups (p>0.05). After and 144h, highest solubility was observed in the terpineol paste (p<0.05), followed by the CTZ paste (p<0.05). No differences were detected for cinnamaldehyde, terpineol+cinnamaldehyde and chlorhexidine pastes (p>0.05). Conclusion: Pastes containing cinnamaldehyde or terpineol+cinnamaldehyde showed antibacterial activity against E. faecalis similar to CTZ paste, with lower solubility.

Comparison of the Self-Adjusting File and Hedström File Used as Supplementary Instruments for the Remaining Filling Material Removal During Retreatment of C-Shaped Canals: A Micro-CT Study.

Objective: The aim of this study was to evaluate the use of Self-adjusting file (SAF) system and Hedström (H) file for removing remaining filling material (RFM) from C-shaped canals. Methods: 20 C-shaped mandibular second molars with C1 configurations were instrumented, filled with tagger´s hybrid technique. Samples were divided into 2 groups (n=10). Reciproc R25 and a Mtwo 35/04 file were used for retreatment in both groups. Then, a 2.0 SAF file (group I) and a #35 H file (group II) were used as supplementary steps for RFM removal. Micro-CT scanning was performed after every procedure. Total volumes were calculated and converted into percentages. Also, the minimum wall thickness at 3, 5, 7 mm from apex was calculated. The Prism 7.0 software was used as the analytical tool with a significance of 5%. Results: Initial obturation removal was approximately 64% in group I and 67% in Group II. The apical third had the highest values of RFM. The use of a H file significantly reduced the RFM compared to SAF in the total canal length respectively (30% vs 18%) and at 1-3 mm and 3-6 mm when compared to the use of SAF. A statistically significant decrease of RFM and minimum wall thickness were observed in both groups (P<0.05). Conclusion: None of the retreatment techniques completely removed RFM. The apical region was the more unaffected area. Also, the SAF file was less effective than the H file in removing the RFM. Although C-shaped canals possesses thinner dentinal wall thickness, no excessive dentine removal was observed after each instrument use.

Efficacy of Two Different Nickel-Titanium Rotary Systems in Retreatment Procedure With or Without Laser-Activated Irrigation: An In Vitro Study.

Objective: The aim of this study was to compare the efficacy of HyFlex EDM (Coltene/Whaledent, Altstätten, Switzerland) and ProTaper Universal Retreatment Nickel-Titanium (NiTi) Systems [The ProTaper Universal Retreatment (PTR), Dentsply Maillefer, Ballaigues, Switzerland] in the removal of the root canal filling materials with or without laser activated irrigation. Materials and methods: The root canals of 60 human mandibular premolars were instrumented with K files up to size 35 at a working length; the step-back procedure was performed in 1 mm increments up to size 50. Next, the teeth were obturated using the lateral compaction technique with gutta-percha and resin-based sealer, and they were randomly divided into two groups (n = 30) according to the retreatment systems: PTR and HyFlex EDM NiTi rotary files. Then, each group was divided into two subgroups (n = 15), laser [photon-induced photo-acoustic streaming (PIPS); Fotona, Ljubljana, Slovenia] activated irrigation and conventional needle irrigation group. Following these procedures, the specimens were evaluated using micro-computed tomography. Results: There was no significant difference between the instrumentation systems regarding the cleaning efficacy (χ2 = 0.754; p = 0.86). Additionally, PIPS method did not have a significant effect on the removal of the filling material compared to conventional needle irrigation. Conclusions: Both instrumentation systems were effective in removing the filling material, but neither was able to remove the filling material completely. PIPS method did not show a significant additional effect regarding the removal of filling material.

Comparison of instrumentation time and obturation quality between hand K-file, H-files, and rotary Kedo-S in root canal treatment of primary teeth: A randomized controlled trial.

INTRODUCTION: Pulpectomy has been a treatment of choice in all necrotic primary teeth. Advancing technology has brought the rotary system to reduce the manual dexterity and improve the quality of treatment for pulpectomy. Advancing technology in pediatric dentistry should be used for the better treatment protocol. AIM: The aim of this study is to compare the obturation quality and instrumentation time after root canal instrumentation with rotary Kedo-S files, hand K-files, and H-files in primary molars. MATERIALS AND METHODS: A randomized control trial where pulpectomy was performed on 75 primary molars equally distributed for instrumentation with K-file, H-files rotary Kedo-S files, respectively. The instrumentation time and obturation quality were noted. RESULTS: Kedo-S files showed the least instrumentation time with better obturation quality as compared to other two groups (P < 0.001). CONCLUSION: Pediatric rotary files Kedo-S has better obturation quality in minimum instrumentation time.

Effect of obturation technique with immediate and delayed post space preparation on apical voids and bond strength of apical gutta-percha.

OBJECTIVE: The purpose of this study was to evaluate the effect of immediate and delayed post space preparation on the sealing ability of two root canal obturation techniques by using micro-computed tomography imaging and a push-out test. METHODS: The root canals of 40 human maxillary premolar teeth were instrumented and divided into four groups: (A) single cone (SC) followed by immediate post space preparation, (B) continuous wave of condensation (CWC) followed by immediate post space preparation, (C) SC followed by delayed post space preparation, and (D) CWC followed by delayed post space preparation. Micro-CT scans were performed for volumetric analysis of voids and filling materials in the apical 4-mm portion. A push-out test was performed, and failure modes (adhesive, cohesive, or mixed) were assessed. Data were analyzed using the Kruskal-Wallis test and one-way analysis of variance. RESULTS: No significant differences were observed among the four groups in terms of the percentage volume of voids of the apical 4 mm or the bond strength of apical gutta-percha. CONCLUSIONS: The percentage volume of voids and bond strength of apical gutta-percha were similar and were not significantly influenced by the timing of post space preparation or the obturation technique.

Comparison of the effectiveness of various rotary and reciprocating systems with different surface treatments to remove gutta-percha and an epoxy resin-based sealer from straight root canals.

AIM: To compare the Reciproc Blue, Reciproc and ProTaper Universal Retreatment systems with regard to the effective removal of epoxy resin-based sealer and gutta-percha during the retreatment of oval, straight root canals. METHODOLOGY: Forty-five extracted, human mandibular first premolars with single straight oval canals were selected on the basis of cone beam computed tomography evaluations. The root canals were instrumented with the ProTaper Next system up to the X2 file, and filled with gutta-percha and epoxy resin-based sealer using the cold lateral condensation technique. After 1 month, the samples were randomly divided into three groups (n = 15) according to the retreatment system used: Reciproc Blue R40, Reciproc R40 and ProTaper Universal. The specimens were scanned at the resolution of 1.2 µm by a microcomputed tomography device after the root filling and retreatment procedures, and the decrease in the volume of filling material after each retreatment protocol was measured. The results were analysed using the Kruskal-Wallis test and additional box-and-whisker plots. RESULTS: Although the volume of the filling material decreased significantly in all three groups (P < 0.05), none of the systems removed the material completely. The Reciproc system removed significantly more material than the ProTaper Universal (P < 0.001) and Reciproc Blue (P = 0.005) systems, with the latter two exhibiting equal volumes of remaining material (P = 0.068). CONCLUSION: The Reciproc system was more effective than the Reciproc Blue and ProTaper Universal Retreatment systems during the removal of filling material from oval, straight canals, although none of the systems completely removed the filling material.

Effectiveness of Reciproc Blue in removing canal filling material and regaining apical patency.

AIM: To compare the efficiency of M-Wire Reciproc and Reciproc Blue instruments in the removal of root filling material and in their ability to regain apical patency through micro-computed tomographic (micro-CT) analysis. METHODOLOGY: Ten anatomically matched pairs of teeth, with a single oval-shaped straight canal, were selected and scanned in a micro-CT device. The root canals were prepared with M-Wire Reciproc R25 instruments and filled with gutta-percha and AH Plus sealer. The root canals were then randomly allocated into two groups (n = 10), according to the instrument used: M-Wire Reciproc and Reciproc Blue. The canals were retreated up to instrument sizes 25 and then 40 in both groups. The surface area and volume of residual filling material were assessed using micro-CT imaging after the retreatment procedures. The time required to remove the root fillings was recorded. Data were analysed statistically using t-test with a significance level of 5%. RESULTS: No significant difference (P > 0.05) was observed between the instruments in terms of the volume of residual root filling material. Apical enlargement from size 25 to 40 significantly improved the removal of filling materials (P < 0.05). It was possible to regain apical patency in all specimens from both M-Wire Reciproc and Reciproc Blue groups. No difference was observed in the time required to perform the retreatment between the instruments. CONCLUSIONS: Both M-Wire Reciproc and Reciproc Blue instruments were effective in removing filling materials from oval-shaped straight canals. Apical patency was reestablished in all specimens.

Comparative evaluation of three obturation techniques in primary incisors using digital intra-oral receptor and C.B.C.T-an in vitro study.

OBJECTIVES: Successful pulpectomy in primary teeth depends on quality of obturation. It can be evaluated using digital intra-oral receptor (D.I.O.R) and cone beam computed tomography (C.B.C.T). The purposes of this study were to compare 3 different obturation techniques such as lentulospiral, insulin syringe, and endodontic plugger in primary incisors and to evaluate its quality of obturation using D.I.O.R and C.B.C.T technique. MATERIALS AND METHODS: Thirty-three extracted primary incisors were biomechanically prepared and obturated with zinc oxide eugenol cement by 3 different obturation techniques. The obturation was evaluated for length of obturation and voids using D.I.O.R and C.B.C.T methods. RESULTS: There was a statistically significant difference between all the groups in length of obturation (P = 0.02) in both D.I.O.R and C.B.C.T. Significant differences (P = 0.03) were present in number of voids among 3 obturation techniques in C.B.C.T. Statistically more voids were observed with D.I.O.R in lentulospiral (P = 0.04) group and in insulin syringe (P = 0.02) group. CONCLUSIONS: Acceptable result was obtained with lentulospiral in length of obturation compared to insulin syringe and endodontic plugger technique. Insulin syringe technique resulted in increased underfilling with least number of voids. More number of voids were seen in middle one-third and least number of voids were observed at apical one third of the root among all the 3 techniques of obturation. The study concluded that void identification is improved with D.I.O.R compared to C.B.C.T. CLINICAL RELEVANCE: Lentulospiral reported effective length of obturation, while insulin syringe with least number of voids. D.I.O.R (2-Dimensional) is efficient in detecting voids compared to C.B.C.T (3-Dimensional) in obturated primary teeth.

Obturation quality of calcium silicate-based cements placed with different techniques in teeth with perforating internal root resorption: a micro-computed tomographic study.

OBJECTIVES: To evaluate and compare the obturation quality of mineral trioxide aggregate (MTA) and Biodentine placed with hand condensation or indirect ultrasonic activation technique in teeth models simulating perforating internal root resorption (IRR) using micro-computed tomographic (micro-CT) imaging. MATERIALS AND METHODS: Standardized models with perforating IRR cavities were created using 40 extracted single-rooted human teeth and randomly divided into four groups (n = 10). The specimens were obturated with either MTA or Biodentine and the placement technique applied was either hand condensation or indirect ultrasonic activation. Micro-CT scans were performed for the volumetric analysis of voids and filling materials in the resorption cavities and apical portion of the specimens. Data were analyzed using one-way analysis of variance and paired t test. RESULTS: No significant difference was observed between the groups in terms of the percentage volume of filling materials (p > 0.05). The apical portion of the specimens significantly presented less percentage volume of filling materials than the resorption cavities in each group (p < 0.05). CONCLUSIONS: No placement technique produced void-free fillings in teeth with perforating IRR. There was no significant difference between the obturation quality of Biodentine and MTA. The obturation quality in the apical portion of the root canals was inferior than that in the resorption cavities. CLINICAL RELEVANCE: The obturation of the apical region of teeth with perforating IRR is challenging irrespective of the material type and placement technique.

Influência do retratamento na formação de microtrincas dentinárias em molares inferiores obturados com o cimento biocerâmico total fill: análise por micro-ct / Influence of retreatment on the formation of dentinal microcracks in lower molars filled with total bioceramic cement fill: micro-ct analysis

Objetivo Este estudo teve como objetivo avaliar a incidência de microtrincas dentinárias após a remoção do material obturador utilizando o cimento biocerâmico TotalFill BC através de análises de microtomografia computadorizada (micro-CT). Metodologia Vinte raízes mesiais de molares mandibulares foram obturadas com guta percha e cimento Total Fill BC e em seguida o material obturador foi removido. As amostras foram escaneadas por micro-CT antes do preparo químico-mecânico, após a obturação e posteriormente a remoção do material obturador. As imagens transversais das raízes mesiais obtidas após a obturação foram analisadas e comparadas com as imagens após a remoção do material obturador, utilizando o programa Image J. Resultados Dos 24.444 cortes transversais analisados, 5,67% apresentaram algum defeito de dentina, sendo que nas imagens iniciais foram encontradas 0,51%, nas imagens pós obturação 2,58%, e nas imagens obtidas após a desobstrução 2,58%. Nas análises comparando as imagens iniciais e pós-obturação foram observados 1,65% dos cortes com novas microtrincas. Todos os defeitos dentinários identificados na análise das imagens obtidas após a remoção do material obturador já estavam presentes nas imagens correspondentes obtidas após a obturação. Desta forma, nenhuma nova microfissura foi observada após remoção do material obturador. Conclusão O estudo não visualizou a produção de novas microtrincas dentinárias durante a fase de desobstrução do retratamento endodôntico. (AU)

Aim The present study aimed to evaluate the frequency of dentinal micro-cracks after removal of the filling material using the TotalFill BC bioceramic-based root canal sealer through microcomputed tomography (micro-CT) analyzes. Methodology Twenty mesial roots of mandibular molars were filled with gutta-percha and TotalFill BC sealer and then the filling material was removed. The specimens were scanned by micro-CT, before instrumentation, after filling and after removal of the filling material. Subsequently, the transversal images of the mesial roots obtained after filling were analyzed and compared with that obtained after removal of the filling material, using the program Image J. Results Among the 24.444 cross sections analyzed, 5,67% presented some type of defect, with 0.51% in the initial images, 2.58% in the post-filling images and 2.58% in the final images. In the analysis comparing the initial images with the post-filling, 1,65% of the sections presented new microcracks. All the dentin defects identified in the analysis of the images obtained after the removal of the filling material were already present in the corresponding images obtained after the filling. Therefore, no new microcrack was observed after removal of the filling material. Conclusion The study did not visualize the production of new dentin microcracks during the removal of filling material in the endodontic retreatment. (AU)