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Ali Shalan L, Al-Huwaizi HF. Microhardness and energy dispersive X-ray evaluation of dentinal walls following chemical and electrochemical dissolution of fractured nickel-titanium file: An in vitro study. Heliyon 2024; 10:e35902. [PMID: 39224390 PMCID: PMC11367024 DOI: 10.1016/j.heliyon.2024.e35902] [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: 11/23/2023] [Revised: 08/02/2024] [Accepted: 08/06/2024] [Indexed: 09/04/2024] Open
Abstract
Purpose Chemical dissolution of nickel-titanium (NiTi) files involves the application of a fluoride solution in direct contact with a damaged instrument, whereas electrochemical dissolution involves the application of an electrical current to the electrolyte, which accelerates fragment dissolution. This study aimed to determine the hardness and concentration of calcium and phosphorus (Ca and P) ions in dentinal walls following chemical and electrochemical dissolution of fractured ProTaper F2 files with a novel chemical solution. Materials & Methods : Thirty human maxillary first molar palatal roots with fractured ProTaper F2 files in the middle third (length, 2.5 mm were divided into three groups according to the treatment techniques used with a novel solution (NaF 12 g/L + NaCl2 60 g/L + MgCl2 60 g/L + CaCl2 60 g/L) at pH 5: Group 1: distilled water (control group), Group 2: electrochemical dissolution, and Group 3: chemical dissolution using the novel solution. The novel solution was placed for 10 min using an electrochemical technique, and for 30 min in contact with the separated instrument in the chemical group. The Vickers microhardness test was performed in three areas: at 3, 6, and 9 mm from the apex, and an energy-dispersive X-ray test for both Ca and P ions was performed. The analysis of variance (ANOVA) and Tukey's tests were used for statistical analysis. Results According to the one-way ANOVA analysis, no difference was observed between the tested approaches (P > 0.05) in the three areas evaluated (3, 6, and 9 mm), with no difference in the Ca/P ratio between the tested groups. Conclusion Compared to the control group, the use of chemical and electrochemical dissolution methods with the novel solution did not affect dentin hardness or dentinal structure in terms of the Ca/P ratio, thereby indicating promising results while saving time.
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Affiliation(s)
- Linz Ali Shalan
- Department of Conservative and Esthetic Dentistry, College of Dentistry, University of Baghdad, Iraq
| | - Hussain F. Al-Huwaizi
- Department of Conservative and Esthetic Dentistry, College of Dentistry, University of Baghdad, Iraq
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ORMIGA F, AMARAL CCF, VIEIRA FM, RISSO PDA, SILVA ABD, ALMEIDA M, SENA R, FERES-FILHO EJ, GRANJEIRO JM, GOMES JADCP. Ionic concentration in periradicular medium after dissolution of endodontic file fragments: an in vitro study. Braz Oral Res 2022; 36:e015. [DOI: 10.1590/1807-3107bor-2022.vol36.0015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/09/2021] [Indexed: 11/22/2022] Open
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Amaral CCF, Ormiga F, Araújo OMO, Lopes RT, Gomes JACP. Electrochemical dissolution of nickel-titanium instrument fragments in root canals of extracted human maxillary molars using a small reservoir of electrolyte. Int Endod J 2020; 53:1559-1568. [PMID: 32767773 DOI: 10.1111/iej.13381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 08/03/2020] [Indexed: 01/29/2023]
Abstract
AIM To evaluate the viability of the electrochemical dissolution of fragments of fractured NiTi instruments in root canals of extracted human maxillary molars, using two electrodes and the solution restricted to a small reservoir coupled to the pulp chamber. The primary hypothesis was that this method enables the reduction of fragment volume and re-establishment of the root canal path with a size 08 K-file, both in simulated canals and in extracted human maxillary molars. METHODOLOGY Fragments of F1 ProTaper instruments were polarized in simulated root canals and in distobuccal root canals of extracted maxillary molars using a new method, with the solution restricted to a small acrylic microcell coupled to each resin block or pulp chamber. Two electrodes were used, where one was kept in contact with the intracanal fragment and another was positioned in the solution present in the acrylic microcell. After the tests, a size 08 K-file was used passively to verify the possibility of bypassing the fragment, which was also confirmed by radiographic analysis. Micro-CT analysis of the teeth was used before and after fragment dissolution to evaluate the volume, length and porosity of the fragments. The D'Agostino-Pearson normality test was used to verify the distribution of the data. A paired t-test (P < 0.05) was used to compare the volume, length and porosity of the fragments before and after the dissolution tests. RESULTS After dissolution, all fragments could be bypassed with a size 08 K-file in both simulated canals and in extracted teeth. The dissolution process did not result in significant reduction of neither the fragment length nor the fragment porosity. However, it resulted in a significant reduction of fragment volume (paired t-test, P < 0.05). CONCLUSION The electrochemical dissolution of fragments of NiTi files in root canals of extracted human maxillary molars using two electrodes, and the solution restricted to a small reservoir coupled to the pulp chamber resulted in a significant reduction of fragment volume. The re-establishment of the root canal path with the passive insertion of size 08 K-files was possible in all samples after the tests, both in simulated canals and in extracted teeth.
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Affiliation(s)
- C C F Amaral
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - F Ormiga
- Department of Dental Clinic, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - O M O Araújo
- Nuclear Engineering Program, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - R T Lopes
- Nuclear Engineering Program, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - J A C P Gomes
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Cassol LG, Kowalczuck A, Carneiro E, Westphalen VPD, Laurindo CAH, da Silva Neto UX. Evaluation of fluoride and sodium hypochlorite solutions during the electrochemical dissolution of conventional NiTi instruments and Gold thermomechanically treated NiTi instruments. Int Endod J 2019; 53:513-518. [PMID: 31691303 DOI: 10.1111/iej.13244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 11/04/2019] [Indexed: 11/30/2022]
Abstract
AIM To compare the dissolution time of two solutions, a fluoride solution and a sodium hypochlorite solution, both saturated with sodium chloride, during the electrochemical dissolution of instruments consisting of conventional nickel-titanium alloy and Gold thermomechanically treated nickel-titanium alloy. METHODOLOGY Two solutions, an NaF solution consisting of 12 g L-1 NaF with 180 g L-1 NaCl and an NaOCl solution consisting of 2.5% NaOCl with 180 g L-1 NaCl, were evaluated in a polarization test of a sample of 48 ProTaper Universal F1 (PTU F1) and WaveOne Gold Small (WOGS) instruments. The electric potentials were 0.5 V and 5 V for the NaF and NaOCl solutions, respectively. The electrochemical cell consisted of three electrodes for the polarization test of the PTU F1 and WOGS instruments, which had 6 mm of the tip immersed in the test solutions. The electric current was recorded for 540 s. If complete dissolution of the immersed tip occurred in less than the expected time, the experiment was considered complete. The time variations (in seconds) of the instruments in the solutions were measured. Data were subjected to statistical analysis using the Mann-Whitney, Kruskal-Wallis and Dunn tests. The corrosion patterns of the instruments were evaluated by scanning electron microscopy (SEM). RESULTS The NaF and NaOCl solutions were associated with significantly different (P = 0.000) dissolution times of the instrument, with mean values of 12.96 s and 83.63 s, respectively. There was no significant difference (P = 0.649) in dissolution time between the PTU F1 and WOGS instruments. CONCLUSIONS NaF and NaOCl solutions were able to electrochemically dissolve PTU F1 and WOGS instruments. However, the NaF solution achieved dissolution in significantly less time.
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Affiliation(s)
- L G Cassol
- Department of Endodontics, School of Life Sciences, Curitiba, Brazil
| | - A Kowalczuck
- Department of Endodontics, School of Life Sciences, Curitiba, Brazil
| | - E Carneiro
- Department of Endodontics, School of Life Sciences, Curitiba, Brazil
| | - V P D Westphalen
- Department of Endodontics, School of Life Sciences, Curitiba, Brazil
| | - C A H Laurindo
- Department of Mechanical Engineering, Polytechnic School, Pontifical Catholic University of Paraná, Curitiba, Brazil
| | - U X da Silva Neto
- Department of Endodontics, School of Life Sciences, Curitiba, Brazil
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Kowalczuck A, Borges MM, Kruger H, Piasecki L, da Silva Neto UX, Westphalen VPD, Laurindo CAH, Carneiro E. Microscopic evaluation of the dentinal walls of extracted human teeth following electrochemical dissolution of fragmented nickel-titanium instruments. Microsc Res Tech 2019; 82:1529-1534. [PMID: 31184801 DOI: 10.1002/jemt.23317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 05/01/2019] [Accepted: 05/27/2019] [Indexed: 01/17/2023]
Abstract
Electrochemical dissolution is a method in which fluoridated solution in direct contact with the fractured instrument receives an electrical current that speeds up fragment dissolution. The aim of this study was to assess the integrity of dentinal walls during the electrochemical dissolution of fractured rotary endodontic instruments in extracted human teeth. Forty-five human mandibular incisors subjected to the electrochemical dissolution process using fluoride solution with low NaCl concentration (LC group: NaF 12 g/L + NaCl 1 g/L, pH = 5.0), fluoride solution with saturating NaCl concentration (SC group: NaF 12 g/L + NaCl 180 g/L, pH = 5.0) and distilled water (control group) were evaluated. For each group, 15 incisors were submitted for the scanning electron microscopy (SEM) evaluation. The roots were sectioned longitudinally; each hemisection was analyzed (n = 30), and energy-dispersive spectroscopy (EDS) was performed. The amount of dentinal tubule openings was analyzed by SEM. Statistical analyses were performed. The test solutions did not alter the amount of dentinal tubule openings when compared with the control group. No Ni or Ti was impregnated into the dentinal tubules after electrochemical techniques. The dentinal structure remained unchanged following the electrochemical dissolution method.
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Affiliation(s)
- Alexandre Kowalczuck
- Department of Endodontics, Pontifical University Catholic of Paraná, Curitiba, Brazil
| | - Murilo M Borges
- Department of Endodontics, Pontifical University Catholic of Paraná, Curitiba, Brazil
| | - Helington Kruger
- Department of Endodontics, Pontifical University Catholic of Paraná, Curitiba, Brazil
| | - Lucila Piasecki
- Department of Periodontics & Endodontics, University at Buffalo, EUA, Buffalo, New York
| | | | - Vânia P D Westphalen
- Department of Endodontics, Pontifical University Catholic of Paraná, Curitiba, Brazil
| | - Carlos A H Laurindo
- Department of Mechanical Engineering, Pontifical University Catholic of Paraná, Curitiba, Brazil
| | - Everdan Carneiro
- Department of Endodontics, Pontifical University Catholic of Paraná, Curitiba, Brazil
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6
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Separated Instrument in Endodontics: Frequency, Treatment and Prognosis. BALKAN JOURNAL OF DENTAL MEDICINE 2018. [DOI: 10.2478/bjdm-2018-0022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Summary
Instrument separation during endodontic therapy is a frequent accident with rotary instruments being more likely to separate than manual ones. The treatment of cases with a separated instrument can be either conservative or surgical. A conservative approach involves the following treatment choices: a) bypass of the fragment, b) removal of the fragment, c) instrumentation and obturation coronally to the fragment. Concerning the removal of a separated instrument, a variety of techniques and systems have been developed. Ultrasonics, in combination with the operative microscope constitute the most effective and reliable tools for removing a separated endodontic instrument from a root canal. The likelihood of successful removal depends on: the level of separation (coronal, middle or apical third); location in relation to the root canal curvature; the type of separated instrument; its length; the degree of canal curvature and the tooth type. Several complications may occur during the management of a separated instrument: separation of the ultrasonic tip or file used for bypassing or removing the instrument; further separation of the fragment; perforation; ledge; extrusion of the file into periapical tissues; tooth weakening due to dentin removal, as well as excessive temperature rise in periodontal tissues. Prognosis for a tooth retaining a separated instrument depends on the presence of a periapical lesion, the microbial load of the root canal during the time of separation and the quality of the obturation.
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Amaral CCF, Ormiga F, Boldrini LC, Miranda PG, Mendonça TA, Granjeiro JM, Gomes JACP. Evaluation of the effects of the solution used for electrochemical dissolution of nickel-titanium endodontic files on dentine structure, microhardness and cell viability. Int Endod J 2018; 51:1434-1445. [PMID: 29763971 DOI: 10.1111/iej.12950] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 05/08/2018] [Indexed: 12/27/2022]
Abstract
AIM To evaluate the effects of the [NaF 12 g L-1 + NaCl 1 g L-1 ] solution used in the electrochemical dissolution process of fractured endodontic files, as well as its NiTi-containing product, on dentine hardness, topography and human fibroblast viability. METHODOLOGY Sixty single-rooted human teeth were evaluated for dentine microhardness using the Vickers hardness test and the area and number of dentinal tubules by scanning electron microscopy. The samples were divided according to the dentine surface treatment: distilled water; 17% EDTA; [NaF 12 g L-1 + NaCl 1 g L-1 ]; and 17% EDTA + [NaF 12 g L-1 + NaCl 1 g L-1 ]. Thirty-six single-rooted human teeth were divided according to the irrigation protocol: Dulbecco's Modified Eagle's Medium + 10% foetal bovine serum; 5.25% NaOCl; [NaF 12 g L-1 + NaCl 1 g L-1 ]; and [NaF 12 g L-1 + NaCl 1 g L-1 + NiTi]. The extracts in contact with the apical foramen were used in the MTT assay to evaluate human fibroblast viability, with dilutions of 100%, 50%, 25% and 12.5%. Statistical tests used were paired t-tests, one-way anova, Tukey's test, Kruskal-Wallis test and Dunn's post-test. RESULTS The [NaF 12 g L-1 + NaCl 1 g L-1 ] solution did not modify dentine microhardness or the average dentinal tubule area. However, EDTA induced changes in dentine structure and microhardness (P < 0.05). The [NaF 12 g L-1 + NaCl 1 g L-1 ] solution, and its NiTi-containing product had lower cytotoxicity than NaOCl at dilutions of 25% and 50% (P < 0.01). CONCLUSIONS The [NaF 12 g L-1 + NaCl 1 g L-1 ] solution did not alter dentine microhardness or damage the dentine structure. It also demonstrated lower cytotoxicity than NaOCl.
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Affiliation(s)
- C C F Amaral
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - F Ormiga
- Department of Dental Clinic, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - L C Boldrini
- Bioengineering Laboratory, National Institute of Metrology, Quality and Technology (INMETRO), Duque de Caxias, Brazil.,Postgraduate Program in Translational Biomedicine - BIOTRANS - Unigranrio, Inmetro, Uezo, Rio de Janeiro, Brazil
| | - P G Miranda
- Bioengineering Laboratory, National Institute of Metrology, Quality and Technology (INMETRO), Duque de Caxias, Brazil
| | - T A Mendonça
- Postgraduate Program in Translational Biomedicine - BIOTRANS - Unigranrio, Inmetro, Uezo, Rio de Janeiro, Brazil.,Department of Endodontics, UNIGRANRIO - University of Grande Rio, Duque de Caxias, Brazil
| | - J M Granjeiro
- Bioengineering Laboratory, National Institute of Metrology, Quality and Technology (INMETRO), Duque de Caxias, Brazil.,Postgraduate Program in Translational Biomedicine - BIOTRANS - Unigranrio, Inmetro, Uezo, Rio de Janeiro, Brazil.,Department of Dental Technic,, Dental School, Fluminense Federal University, Rio de Janeiro, Brazil
| | - J A C P Gomes
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Kowalczuck A, Silva Neto UX, Fariniuk LF, Westphalen VPD, Laurindo CAH, Carneiro E. Electrochemical dissolution of fractured nickel-titanium instruments in human extracted teeth. Int Endod J 2016; 50:578-585. [PMID: 27101226 DOI: 10.1111/iej.12654] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/19/2016] [Indexed: 11/26/2022]
Abstract
AIM To assess the effect of sodium chloride concentration in fluoridated solutions during the electrochemical dissolution of fractured rotary endodontic instruments. METHODOLOGY Two solutions were assessed (solution 1: NaF 12 g L-1 + NaCl 1 g L-1 , pH = 5.0; and solution 2: NaF 12 g L-1 + NaCl 180 g L-1 , pH = 5.0) using two tests: the ProTaper Universal F1 (PTU F1) instrument polarization test and the polarization test for intracanal PTU F1 fragments fractured in mandibular incisors. In the first test, two sets of five instruments were separately and partially immersed in each solution, and the electrical current was evaluated over 30 min. In the second test, 45 PTU F1 instruments were fractured within the root canals of mandibular incisors and subjected to potentiodynamic polarization for 30 min. The electrical current and the variations in the length of PTU F1 fragments were measured. The data were analysed statistically (anova and Wilcoxon and Mann-Whitney tests, respectively). RESULTS Solution 2 was associated with more corrosive effects in both tests. In the first test, the PTU F1 instruments immersed in solution 2 had a higher electrical current (P < 0.001) and had a total dissolution time of approximately 540 s. In the second test, a larger difference between the baseline and final lengths of the fragments was noted in solution 2 (P = 0.011). CONCLUSION Saturation of fluoridated solution with sodium chloride led to an increase in electrical current and microscopic reductions in the length of fractured instrument fragments subjected to electrochemical dissolution.
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Affiliation(s)
- A Kowalczuck
- Department of Endodontics, School of Health and Biosciences, Pontifical University Catholic of Paraná, Curitiba, Paraná, Brazil
| | - U X Silva Neto
- Department of Endodontics, School of Health and Biosciences, Pontifical University Catholic of Paraná, Curitiba, Paraná, Brazil
| | - L F Fariniuk
- Department of Endodontics, School of Health and Biosciences, Pontifical University Catholic of Paraná, Curitiba, Paraná, Brazil
| | - V P D Westphalen
- Department of Endodontics, School of Health and Biosciences, Pontifical University Catholic of Paraná, Curitiba, Paraná, Brazil
| | - C A H Laurindo
- Department of Mechanical Engineering, Polytechnic School, Pontifical University Catholic of Paraná, Curitiba, Paraná, Brazil
| | - E Carneiro
- Department of Endodontics, School of Health and Biosciences, Pontifical University Catholic of Paraná, Curitiba, Paraná, Brazil
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Tang WR, Smales RJ, Chen HF, Guo XY, Si HY, Gao LM, Zhou WB, Wu YN. Prevention and management of fractured instruments in endodontic treatment. World J Surg Proced 2015; 5:82-98. [DOI: 10.5412/wjsp.v5.i1.82] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/12/2014] [Accepted: 01/12/2015] [Indexed: 02/06/2023] Open
Abstract
Intracanal instrument fracture is an unpredictable and problematic occurrence that can prevent adequate cleaning and shaping procedures and influence the prognosis of endodontic treatment. The prevalence of instrument fracture is reported to range between 0.28% and 16.2%. This article presents an overview of the prevention and management of instruments fractured during endodontic therapy on the basis of literature retrieved from PubMed and selected journal searches. Instrument fracture occurs because of reduced metal fatigue and/or torsional resistance. The reasons include canal morphology and curvature, manufacturing processes and instrument design, instrument use times and technique, rotational speeds and operator experience. With the development of various equipment and techniques, most of the retained instrument separations can be removed safely. However, in canals without associated periapical disease not every fractured separation should be removed from difficult locations because of the increased risk for root perforation and fracture. In difficult cases, either retain or bypass the fragment in the root canal and ensure regular follow-up reviews. Fractured instruments retained in the presence of periapical disease reduce significantly the prognosis of endodontically treated teeth, indicating a greater need to attempt the removal or bypass of the file separations. Apical surgery might be required in some instances, emphasizing the importance of preventing instrument fracture.
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Monteiro JCDC, Kuga MC, Dantas AAR, Jordão-Basso KCF, Keine KC, Ruchaya PJ, Faria G, Leonardo RDT. A method for retrieving endodontic or atypical nonendodontic separated instruments from the root canal: a report of two cases. J Contemp Dent Pract 2014; 15:770-4. [PMID: 25825106 DOI: 10.5005/jp-journals-10024-1615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AIM This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures. BACKGROUND The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice. CASE REPORT This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment. CONCLUSION The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device. CLINICAL SIGNIFICANCE The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.
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Affiliation(s)
| | - Milton Carlos Kuga
- Associate Professor, Faculdade de Odontologia de Araraquara, FOAr-UNESP, Departamento de Odontologia Restauradora - 3°andar. Rua Humaitá 1680 Centro CEP 14801-903, Araraquara São Paulo, Brazil, e-mail:
| | - Andrea Abi Rached Dantas
- Professor, Department of Restorative Dentistry, Araraquara Dental School, UNESP-Univ Estadual Paulista, Araraquara, SãoPaulo, Brazil
| | | | - Katia Cristina Keine
- Postgraduate Student, Department of Restorative Dentistry, Araraquara Dental School, UNESP-Univ Estadual Paulista, Araraquara, SãoPaulo, Brazil
| | - Prashant Jay Ruchaya
- Postdoctoral Student, Department of Physiology and Pathology, Araraquara Dental School, UNESP-Univ Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Gisele Faria
- Professor, Department of Restorative Dentistry, Araraquara Dental School, UNESP-Univ Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Renato de Toledo Leonardo
- Associate Professor, Department of Restorative Dentistry, Araraquara Dental School, UNESP-Univ Estadual Paulista, Araraquara, São Paulo, Brazil
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Ormiga F, Aboud LRL, Gomes JACP. Electrochemical-induced dissolution of nickel-titanium endodontic instruments with different designs. Int Endod J 2014; 48:342-50. [PMID: 24871818 DOI: 10.1111/iej.12320] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 05/22/2014] [Indexed: 12/28/2022]
Abstract
AIM To compare the active dissolution process of K3, ProTaper and Mtwo NiTi endodontic rotary instruments in chloride and fluoride containing solutions. METHODS Anodic polarization of K3 size 20, 0.06 taper, ProTaper size F1 and MTwo size 20, 0.06 taper instruments was performed, and anova (P < 0.05) was used to compare the weight loss, the time of dissolution and the electrical charge generated by the groups of instruments. Fragments of the instruments were polarized in simulated root canals to evaluate the dissolution process. After the tests, a size 10 K-file was used to verify whether the fragment could be bypassed. Radiographic analysis of the simulated canals was used before and after the tests to verify fragment dissolution. RESULTS A progressive consumption of the instruments was observed. K3 and ProTaper instruments had significantly greater weight loss than Mtwo instruments after 30 min of polarization. K3 instruments had the highest values of total electrical charge, and MTwo instruments the lowest (P < 0.05). After 60 min, the anodic polarization of instrument fragments in simulated root canals resulted in their partial dissolution. CONCLUSION The anodic polarization of K3, ProTaper and MTwo instruments resulted in their progressive consumption with increasing polarization time. Sixty minutes anodic polarization of the various NiTi instrument fragments in simulated root canals resulted in their partial dissolution.
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Affiliation(s)
- F Ormiga
- Department of Endodontics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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12
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Amaral CCF, Ormiga F, Gomes JACP. Electrochemical-induced dissolution of stainless steel files. Int Endod J 2014; 48:137-44. [PMID: 24702197 DOI: 10.1111/iej.12292] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 04/02/2014] [Indexed: 11/30/2022]
Abstract
AIM To investigate the effectiveness of the dissolution process when hand stainless steel files are polarized in solutions containing chloride and fluoride to promote their dissolution. METHODOLOGY Redox curves and anodic polarization curves were obtained to determine the conditions necessary for the dissolution of stainless steel endodontic files. Anodic polarization of sizes 20 and 30 files was performed, and a t-test (P < 0.05) was used to compare the weight loss, the time of dissolution and the electrical charge generated by both groups of files. Fragments were polarized in simulated root canals to evaluate the dissolution process. After the tests, a size 10 K-file was used to verify the possibility of bypassing the fragment. Radiographic analysis of the simulated canals was used before and after the tests to verify fragment dissolution. RESULTS A progressive consumption of the sizes 20 and 30 files was observed with total polarization times of 7.0 and 9.0 min, respectively. Files with the larger diameters exhibited greater weight loss, longer times of dissolution and generated a greater electrical charge during the active dissolution process (t-test, P < 0.05). After 60 min, the anodic polarization of file fragments in simulated root canals resulted in their partial dissolution. CONCLUSION A 60-min anodic polarization of stainless steel K-file fragments in simulated root canals resulted in their partial dissolution. The fragments could be bypassed after the test.
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Affiliation(s)
- C C F Amaral
- Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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