1
|
Bincelli Seckler IN, Pelegrine RA, Stringheta CP, Lopes RT, de Sá Silva AS, da Silveira Bueno CE. Comparative Evaluation of Supplementary Cleaning Techniques for Removal of Bio-C Sealer and AH-Plus from Oval Root Canals: A Micro-CT Analysis. IRANIAN ENDODONTIC JOURNAL 2024; 19:199-207. [PMID: 39086709 PMCID: PMC11287049 DOI: 10.22037/iej.v19i3.43580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 04/25/2024] [Accepted: 05/03/2024] [Indexed: 08/02/2024]
Abstract
Introduction This study aimed to compare the effectiveness of two endodontic cleaning techniques, passive ultrasonic irrigation (PUI) and the XP-endo Finisher R (XPR) system, in removing residual filling material during endodontic retreatment procedures. Materials and Methods Forty mandibular premolars with oval canals were divided into four groups based on the sealer used (AH-Plus or Bio-C Sealer) and the cleaning technique employed (PUI or XPR). To ensure uniformity of canal volume among groups, initial micro-CT scans were conducted. The canals were instrumented, filled, and then re-instrumented before undergoing either PUI or XPR cleaning techniques. Residual filling material volumes were assessed through micro-CT scans, and statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests. Results Following instrumentation, there was no significant difference in residual filling material volumes between AH-Plus and Bio-C Sealer groups (1.35 mm3and 1.02 mm3, respectively; P>0.05). However, after supplementary cleaning techniques, XPR-cleaned specimens exhibited significantly less residual material compared to PUI-cleaned specimens (0.01 mm3 and 0.29 mm3 for Bio-C Sealer, and 0.07 mm3 and. 0.30 mm3 for AH-Plus, P<0.05). Conclusion The XPR system was found to be more effective than PUI in removing residual filling material from Bio-C Sealer-filled root canals. This highlights its potential as a useful supplementary cleaning technique in endodontic retreatment procedures.
Collapse
Affiliation(s)
| | - Rina Andréa Pelegrine
- Faculdade São Leopoldo Mandic, Instituto de Pesquisa São Leopoldo Mandic, Endodontia, Campinas, SP, Brazil;
| | - Carolina Pessoa Stringheta
- Faculdade São Leopoldo Mandic, Instituto de Pesquisa São Leopoldo Mandic, Endodontia, Campinas, SP, Brazil;
| | - Ricardo Tadeu Lopes
- Laboratory of Nuclear Instrumentation, Alberto Luiz Coimbra Institute of Graduate Studies and Engineering Research (COPPE), Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Aline Saddock de Sá Silva
- Faculdade São Leopoldo Mandic, Instituto de Pesquisa São Leopoldo Mandic, Endodontia, Campinas, SP, Brazil;
| | | |
Collapse
|
2
|
El Hachem C, Chedid JCA, Nehme W, Kaloustian MK, Ghosn N, Rabineau M, Kharouf N, Haikel Y, Mancino D. The Contribution of Various In Vitro Methodologies to Comprehending the Filling Ability of Root Canal Pastes in Primary Teeth. Bioengineering (Basel) 2023; 10:818. [PMID: 37508845 PMCID: PMC10376379 DOI: 10.3390/bioengineering10070818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/06/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023] Open
Abstract
A void-free obturation during root canal treatment on primary teeth is currently very difficult to attain. In this study, the pulpectomy filling abilities of Bio-C Pulpecto (Angelus, Basil, Londrina, Paraná, Brazil) and of zinc oxide eugenol, or "ZOE" (DenPro, Prevest, New York, NY, USA), were compared using several in vitro techniques. Therefore, 30 primary anterior teeth were used in the present in vitro study. Analysis of variance (ANOVA), including a multiple comparison procedure (Holm-Sidak method, Dunn's Method, or Tukey test), was used. On micro-CT, Bio-C Pulpecto exhibited higher void percentages than did ZOE (10.3 ± 3.8%, and 3.5 ± 1.3%), respectively (p < 0.05). With digital microscopy, higher total void percentages were found in the BC (13.2 ± 26.7%) group compared to the ZOE (2.7 ± 2.8%) group (p < 0.05). With the CLSM, mean tubular penetration depths were higher for Bio-C Pulpecto than for ZOE in all canal thirds (p < 0.05). SEM images demonstrated no tags into dentinal tubules in either group throughout the three thirds. Moreover, higher statistically significant flowability was found for Bio-C (2.657 ± 0.06 mm) compared to ZOE (1.8 ± 0.13 mm) (p < 0.05). The findings of this study indicate that neither ZOE nor Bio-C Pulpecto appears to meet the criteria for an ideal root canal filling paste for primary teeth. This study laid the groundwork for future research by determining how micro-CT, digital microscopy, SEM, and CLSM contribute to our understanding of the filling process of primary teeth. More thorough research on the mechanism of root canal obturation on primary teeth is required to achieve a long-term successful root canal therapy in young children.
Collapse
Affiliation(s)
- Claire El Hachem
- Department of Pediatric Dentistry, Faculty of Dentistry, Saint Joseph University, Beirut 1107 2180, Lebanon
| | - Jean Claude Abou Chedid
- Department of Pediatric Dentistry, Faculty of Dentistry, Saint Joseph University, Beirut 1107 2180, Lebanon
| | - Walid Nehme
- Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, 155 5th Street, San Francisco, CA 94103, USA
| | - Marc Krikor Kaloustian
- Department of Endodontics, Faculty of Dentistry, Saint Joseph University, Beirut 1107 2180, Lebanon
| | - Nabil Ghosn
- Craniofacial Research Laboratory, Faculty of Dental Medicine, Saint Joseph University, Beirut 1107 2180, Lebanon
| | - Morgane Rabineau
- Faculté de Chirurgie Dentaire, Fédération de Médecine Translationnelle de Strasbourg and Fédération des Matériaux et Nanoscience d'Alsace, Université de Strasbourg, 67000 Strasbourg, France
- Department of Biomaterials and Bioengineering, INSERM UMR_S 1121, Strasbourg University, 67000 Strasbourg, France
| | - Naji Kharouf
- Department of Biomaterials and Bioengineering, INSERM UMR_S 1121, Strasbourg University, 67000 Strasbourg, France
- Department of Endodontics, Faculty of Dental Medicine, Strasbourg University, 67000 Strasbourg, France
| | - Youssef Haikel
- Department of Biomaterials and Bioengineering, INSERM UMR_S 1121, Strasbourg University, 67000 Strasbourg, France
- Department of Endodontics, Faculty of Dental Medicine, Strasbourg University, 67000 Strasbourg, France
- Pôle de Médecine et Chirurgie Bucco-Dentaire, Hôpital Civil, Hôpitaux Universitaire de Strasbourg, 67000 Strasbourg, France
| | - Davide Mancino
- Department of Biomaterials and Bioengineering, INSERM UMR_S 1121, Strasbourg University, 67000 Strasbourg, France
- Department of Endodontics, Faculty of Dental Medicine, Strasbourg University, 67000 Strasbourg, France
- Pôle de Médecine et Chirurgie Bucco-Dentaire, Hôpital Civil, Hôpitaux Universitaire de Strasbourg, 67000 Strasbourg, France
| |
Collapse
|
3
|
Barakat RM, Almohareb RA, Alsayyar A, Almalki F, Alharbi H. Evaluation of Dentinal Microcracks following Diode Laser- and Ultrasonic-Activated Removal of Bioceramic Material during Root Canal Retreatment. SCANNING 2022; 2022:6319743. [PMID: 36570434 PMCID: PMC9705085 DOI: 10.1155/2022/6319743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/20/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
This study is aimed at evaluating the use of microcomputed tomography (micro-CT) analysis and the dentinal microcrack formation following retreatment of bioceramic sealer employing adjunct laser-activated irrigation and ultrasonic-activated irrigation. Thirty sound human single-canal teeth (n = 30) obturated using the single-cone technique with bioceramic sealer were retreated using nickel-titanium (NiTi) rotary files. The sample was randomly divided into three equal groups: group 1, the control group, was not subjected to further treatment; group 2 underwent ultrasonic activation of irrigants; group 3 underwent active irrigation with a diode laser (980 nm wavelength). Using micro-CT, the teeth were scanned before and after retreatment protocols. Two calibrated experienced observers viewed the cross-sectional images and calculated the number of dentinal defects. The presence of any crack or craze line on the external root surface or internal canal wall was counted. Data were analyzed using Friedman's two-way analysis of variance and Fisher's exact test. Statistical significance was set at p < 0.05. A significant increase occurred in the number of cracks post retreatment protocols, specifically in the coronal and middle canal thirds, compared to pre- and postinstrumentation (p = 0.0001). However, ultrasonic- or laser-activated irrigation did not result in a significant increase in the number of cracks (p = 0.345). NiTi rotary root canal retreatment was associated with a significant increase in dentinal microcracks. However, employing ultrasonic- or laser-activated irrigation as adjunct retreatment techniques did not reveal a significant increase in dentinal microcracks within the roots.
Collapse
Affiliation(s)
- Reem M. Barakat
- Department of Clinical Dental Sciences, College of Dentistry, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Rahaf A. Almohareb
- Department of Clinical Dental Sciences, College of Dentistry, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Aljuharh Alsayyar
- Dental Intern, College of Dentistry, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Fayruz Almalki
- Dental Intern, College of Dentistry, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Hissah Alharbi
- Dental Intern, College of Dentistry, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| |
Collapse
|
4
|
Ortiz-Blanco B, Sanz JL, Llena C, Lozano A, Forner L. Dentin Sealing of Calcium Silicate-Based Sealers in Root Canal Retreatment: A Confocal Laser Microscopy Study. J Funct Biomater 2022; 13:jfb13030114. [PMID: 35997452 PMCID: PMC9397037 DOI: 10.3390/jfb13030114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 07/30/2022] [Accepted: 08/02/2022] [Indexed: 02/01/2023] Open
Abstract
The aim of the present in vitro study was to evaluate the intratubular penetration of three bioceramic sealers in root canal retreatment. Here, 30 single-rooted human teeth were instrumented with the Protaper Universal system and filled with gutta-percha and the epoxy-resin-based sealer AH Plus mixed with rhodamine B. After two weeks in a humid environment, they were re-instrumented with Reciproc Blue and divided into three groups according to the endodontic sealer to be used in the re-filling (n = 10): G1: CeraSeal, G2: TotalFill BC Sealer, G3: TotalFill BC Sealer HiFlow. For the filling, a single cone technique was used, and the respective sealers were mixed with fluorescein. The roots were then sectioned at 2, 5, and 8 mm (apical, medial, and coronal measurement points, respectively) from the apex, and the dentinal tubule penetration depth and percentage of penetration around the canal perimeter were evaluated by means of confocal laser scanning microscopy (CLSM). Penetration between groups was compared using the Kruskal−Wallis test, and within each group using the Wilcoxon test. Statistical significance was established at p < 0.05. A non-significant reduction was found in the penetration depths and in a percentage of penetration around the canal perimeter between AH Plus and the tested calcium-silicate-based sealers (p > 0.05). Consequently, this reduction may not affect the three-dimensional seal of the root canal system in a negative manner. The penetration depth and percentage of penetration around the canal perimeter at both the root canal treatment and retreatment were significantly reduced from the coronal to apical points in all groups (p < 0.05).
Collapse
|
5
|
Tonelli SQ, de Toubes KS, Brabo Pereira AM, de Oliveira Miranda AC, Fernandes LL, Nunes E, Silveira FF. Dentinal microcracks induced by endodontic procedures: A scientometric and bibliometric analysis. J Conserv Dent 2022; 25:78-87. [PMID: 35722065 PMCID: PMC9200181 DOI: 10.4103/jcd.jcd_469_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 12/18/2021] [Accepted: 12/25/2021] [Indexed: 11/29/2022] Open
Abstract
Background Due to the large number of publications relating the occurrence of dental microcracks to endodontic procedures, this bibliometric study evaluated the scientific pattern and trends in literature and provided an overview of scientific production in this context. Aim To analyze, quantify, and characterize the scientific production and trends of published articles evaluating dentinal microcracks formation after endodontic treatment procedures between 2010 and 2020 using bibliometric indicators. Materials and Methods Published articles were found by the search in the Medline (PubMed) and Scopus database using the combination of the following keywords: Dentinal crack OR Dentinal Microcrack OR Crack formation OR Dentin Defect AND Endodontic treatment OR Root canal preparation OR Canal Preparation OR Root canal treatment OR endodontic procedures. The search was also conducted in the Journal of Endodontics and International Endodontic Journal. After inclusion and exclusion criteria application, data from all studies included were collected. Results Among the 556 results after the search, 45 studies were included and analyzed in this bibliometry. No trend was observed in terms of the increasing number of articles over time. Most of them used an in vitro design, compared the effect of different endodontic techniques/systems for root canal instrumentation on dentinal microcracks formation, and were conducted in Turkey, Brazil, and India. Journal of Endodontics and International Endodontic Journal were the main journals with a higher number of articles published. Interestingly, studies conducted with some funding did not lead to higher citation numbers. Moreover, a relevant proportion of studies did not consider the inclusion of control groups, baseline evaluation, or statistical analysis. Micro-CT was the main technique used to evaluate microcrack presence. Conclusion Microcrack formation after the use of different endodontic techniques/systems has been constantly evaluated in the literature. There is a pattern of methodologies used, which may explain the concentration of these studies in specific journals and countries.
Collapse
Affiliation(s)
- Stéphanie Quadros Tonelli
- Department of Dentistry, Pontifical Catholic University of Minas Gerais, Avenida Dom José Gaspar, 500, Belo Horizonte, MG 30535-901, Brazil
| | - Kênia Soares de Toubes
- Department of Dentistry, Pontifical Catholic University of Minas Gerais, Avenida Dom José Gaspar, 500, Belo Horizonte, MG 30535-901, Brazil
| | - André Maués Brabo Pereira
- Department of Civil and Environmental Engineering, University of Brasília, SG-12 Building, Darcy Ribeiro Campus, DF 70910-900, Brazil
| | - Antônio Carlos de Oliveira Miranda
- Department of Computer Science, Institute of Computing, Fluminense Federal University, Rua Passo da Patria, 156, Niterói, RJ 24220-900, Brazil
| | - Letícia Ladeia Fernandes
- Department of Dentistry, Pontifical Catholic University of Minas Gerais, Avenida Dom José Gaspar, 500, Belo Horizonte, MG 30535-901, Brazil
| | - Eduardo Nunes
- Department of Dentistry, Pontifical Catholic University of Minas Gerais, Avenida Dom José Gaspar, 500, Belo Horizonte, MG 30535-901, Brazil
| | - Frank Ferreira Silveira
- Department of Dentistry, Pontifical Catholic University of Minas Gerais, Avenida Dom José Gaspar, 500, Belo Horizonte, MG 30535-901, Brazil
| |
Collapse
|
6
|
Ajina MA, Shah PK, Chong BS. Critical analysis of research methods and experimental models to study removal of root filling materials. Int Endod J 2021; 55 Suppl 1:119-152. [PMID: 34674279 DOI: 10.1111/iej.13650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 12/14/2022]
Abstract
Despite enjoying high favourable outcome rates, root canal treatment is not always successful. Root canal retreatment is a widely practised option for managing a non-healing root treated tooth. A basic distinction between retreatment and initial treatment is the requirement to remove the existing root filling material occupying the root canal space. Only then, can the technical deficiencies and possible causes of failure be addressed. Hence, the successful removal of the root filling material is critical to achieving the objectives of retreatment. Many different materials and techniques have been used for root canal filling, which have been documented in a plethora of studies; these are mainly laboratory studies investigating the removal of root filling materials. To help guide future research, which may then better inform clinical practice in relation to retreatment procedures, the focus of this narrative review is on the research methods and experimental models employed to study the removal of root filling materials. The current available literature demonstrates great variation in the research methodologies used to study the removal of root filling material, including direct visualization by splitting tooth samples or clearing, three-dimensional radiographic imaging including using microcomputed tomography or cone-beam computed tomography, and a combination of these techniques. Depending on the research method employed, variation also exists in quantification of root filling material removal; these include measurements of surface area, volume or weight, and criteria-based (semi-quantitative) assessment. Experimental models, using human teeth or resin models, differ with respect to standardization techniques and replication of the clinical scenario including initial sample preparation, canal filling, allocation and technical aspects of retreatment procedures. Future models should replicate, as closely as possible, the clinical scenario. Currently, microcomputed tomography provides a highly detailed, non-invasive and non-destructive method of objectively assessing and quantifying root filling removal.
Collapse
Affiliation(s)
- Mahdi A Ajina
- Institute of Dentistry, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Pratik K Shah
- Institute of Dentistry, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Bun San Chong
- Institute of Dentistry, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| |
Collapse
|
7
|
Jamleh A, Alghilan M, Alsharif A, Alqahtani N, Aloqayli A, Aljarrah A. Vertical Load and Torque during Postspace Preparation and Their Influence on Microcrack Development. J Prosthodont 2021; 31:252-256. [PMID: 34021671 DOI: 10.1111/jopr.13392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2021] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To investigate, in vitro, the magnitudes of vertical load and torque generated during post space preparation of root canal treated teeth and their influence on microcrack development. MATERIALS AND METHODS Forty extracted premolars with single canals were decoronated. The roots were prepared using ProTaper Next system (Dentsply Sirona) to X3 file, obturated, and provisionalized. After a 3-week incubation period, the roots were distributed into 2 groups according to the post drill system used (ParaPost fiber post and RelyX fiber post). During post space preparation, the vertical load, torque, and preparation time were recorded. Before and after the post space preparation, the roots were imaged with micro-computed tomography (SkyScan 1172; Bruker micro-CT) to detect new microcracks. The data were analyzed using the Mann-Whitney U-test and chi-square test. RESULTS In ParaPost and RelyX, the post space was prepared in 48.31 ±25.28 and 47.71 ±13.36 seconds, respectively (p = 0.360). The peak vertical load generated with ParaPost (20.23 ±7.80 N) was significantly lower than that of RelyX (29.43 ±5.82 N) (p = 0.010). The maximum torque attained with ParaPost (1.42 ±0.61 N.cm) was found to be significantly lower than that of RelyX (3.23 ±1.58 N.cm) (p = 0.000). No post drill fracture or visible deformation was noticed throughout the experiment. New microcracks were found in three ParaPost samples only. CONCLUSIONS The choice of postdrill influenced the loads and torques generated during postspace preparation. The ParaPost system showed favorably lower load and torque values during the postspace preparation compared with the RelyX system.
Collapse
Affiliation(s)
- Ahmed Jamleh
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia.,King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Maryam Alghilan
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia.,King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Asma Alsharif
- Dental Intern, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Nouf Alqahtani
- Dental Intern, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.,Department of Endodontics, King Abdulaziz Medical city, National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Abdulrahman Aloqayli
- Dental Intern, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.,Orthodontics Resident, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Abdulkader Aljarrah
- Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia.,King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| |
Collapse
|
8
|
Dentinal Microcracks Induced by Endodontic Procedures: Suggested Design for Experimental Studies Using Micro-Computed Tomography and Strain Gauges. J Endod 2021; 47:1157-1165. [PMID: 33901544 DOI: 10.1016/j.joen.2021.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/17/2021] [Accepted: 04/14/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION The present study aimed to describe an in vitro study model to investigate root surface strain (RSS) and its correlation with the initiation/propagation of microcracks during different endodontic procedures. METHODS Four lower human incisors extracted microcrack free were selected by micro-computed tomographic imaging. Two strain gauges were bonded to the root surface of each incisor. Then, the teeth were prepared to reproduce the periodontal ligament artificially. The gauges were attached to a data acquisition system. The RSS was recorded during the entire endodontic procedure, which consisted of accessing the endodontic cavity, cleaning, shaping preparation with an Mtwo rotary system (VDW, Munich, Germany), and filling with a standardized technique. Each incisor was submitted to a different retreatment protocol and supplementary cleaning method as follows: (1) Reciproc (RC, VDW) + Flatsonic (FS; Helse, Santa Rosa de Viterbo, Brazil), (2) RC + XP-endo Finisher (XPF; FKG Dentaire, La Chaux-de-Fonds, Switzerland), (3) Mtwo retreatment (MR) + FS, and (4) MR + XPF. Finally, the teeth were rescanned to establish the postoperative microcrack formation by 2 well-trained and blinded examiners. RESULTS The maximum and minimum RSS values were -120 and 510 microstrains, respectively, for all of the files. RC showed the highest RSS values during endodontic retreatment compared with MR. FS demonstrated a higher variation between the minimum and maximum RSS than XPF. No microcracks were observed in the specimens. CONCLUSIONS This preliminary study proposed an experimental model that would combine 2 methods to evaluate the effects of endodontic systems on dentin. Although strain gauges would provide data on the stresses created, the pre- and postoperative evaluation of micro-computed tomographic images would enable microcrack formation to be determined.
Collapse
|