1
|
De-Deus G, Souza EM, Silva EJNL, Belladonna FG, Simões-Carvalho M, Moreira Cavalcante D, Versiani MA. A critical analysis of research methods and experimental models to study root canal fillings. Int Endod J 2022; 55 Suppl 2:384-445. [PMID: 35226760 DOI: 10.1111/iej.13713] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 11/28/2022]
Abstract
Canal filling materials and techniques have been one of the most studied topics in Endodontics. A simple search using the mesh term "root canal filling" in PubMed revealed more than 11,000 articles, an impressive number that is much higher than "root canal disinfection" (5,544 articles) or even the popular "root canal preparation" (8,527 articles). The overriding importance attributed to root filling procedures is not merely intuitive. It derived from the appealing relevance given by the appearance of the white lines in common radiographs grounded on retrospective clinical data that had identified the quality of a root filling as one of the major causes of treatment failure (lack of healing). Since the publication of the Washington study, impressive efforts have been made for the release of new materials and techniques, as well as, for the development of a plethora of laboratory methods to assess the quality of root filling procedures. This narrative review aims to address and discuss the most relevant laboratory methods to assess the root canal filling. Since filling quality improvements have not translated into higher success rates, as reported in longitudinal clinical studies, more than to deliver a simple methodology-based review, this paper aims to present an in-depth critical view on the assessment of laboratory methods used to study the filling materials and techniques. Recent data indicate that the long-term dimensional stability/degradation over time of endodontic sealers plays a central role in the treatment outcome. In this context, laboratory methods should be developed focusing on predicting, at least to some degree, the long-term clinical behaviour of root canal fillings, rather than simply ranking different materials or techniques.
Collapse
Affiliation(s)
- Gustavo De-Deus
- Department of Endodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Erick Miranda Souza
- Department of Dentistry II, Federal University of Maranhão, São Luís, Maranhão
| | - Emmanuel João Nogueira Leal Silva
- Department of Endodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil.,Department of Endodontics, Grande Rio University (UNIGRANRIO), Rio de Janeiro, Brazil
| | | | - Marco Simões-Carvalho
- Department of Endodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | | | | |
Collapse
|
2
|
Özyürek T, Keskin N, Aydın Z. A micro-computed tomographic assessment of oval-shaped root canals obturated with bioceramic sealer using different obturation techniques. BALKAN JOURNAL OF DENTAL MEDICINE 2022. [DOI: 10.5937/bjdm2202100q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Background/Aim: To evaluate void volumes in oval-shaped root canals obturated with three different obturation systems using microcomputed tomography (micro-CT). Material and Methods: Twenty-four distal roots of mandibular molar teeth canals were prepared and randomly divided into three groups (n = 8 in each group). The canals were obturated using single cone (SC), GuttaCore (GC), and warm vertical compaction (WVC) techniques. Each specimen was scanned using a micro-CT device. The volumes of the voids were calculated, and the data were statistically analyzed using a one-way analysis of variance and post hoc Tukey's (P < .05). Results: The void volumes in the WVC group were significantly lower than those in the other groups (P < .05). When different root canal parts were examined, the void volumes increased significantly from the apical to the coronal level in the GC and SC groups (P < .05). In the WVC group, most voids were observed in the middle part (P < .05), whereas there was no significant difference in void volumes in the coronal and apical parts (P > .05). Conclusions: None of the systems provided void-free root filling. However, the void volume using the WVC system was significantly lower than that observed using the other systems.
Collapse
|
3
|
Marconi DF, da Silva GS, Weissheimer T, Silva IA, Só GB, Jahnke LT, Skupien JA, Só MVR, da Rosa RA. Influence of the root canal filling technique on the success rate of primary endodontic treatments: a systematic review. Restor Dent Endod 2022; 47:e40. [DOI: 10.5395/rde.2022.47.e40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/18/2022] [Accepted: 08/10/2022] [Indexed: 12/03/2022] Open
Affiliation(s)
- Daniel Feijolo Marconi
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Giovana Siocheta da Silva
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Theodoro Weissheimer
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Isadora Ames Silva
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Gabriel Barcelos Só
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Leonardo Thomasi Jahnke
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Jovito Adiel Skupien
- Health and Life Sciences Master’s and Dental School, Franciscan University (UFN), Santa Maria, RS, Brazil
| | - Marcus Vinicius Reis Só
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Ricardo Abreu da Rosa
- Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| |
Collapse
|
4
|
The Effect of Ultrasonic Agitation on the Porosity Distribution in Apically Perforated Root Canals Filled with Different Bioceramic Materials and Techniques: A Micro-CT Assessment. J Clin Med 2021; 10:jcm10214977. [PMID: 34768498 PMCID: PMC8584978 DOI: 10.3390/jcm10214977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/22/2021] [Accepted: 10/25/2021] [Indexed: 01/09/2023] Open
Abstract
The present study evaluated the effect of ultrasonic agitation on the porosity distribution of BioRoot RCS/single gutta-percha cone (BR/SC) and MTA Flow (MF) root canals fillings used as apical plugs in moderately curved and apically perforated roots. Eighty mesial root canals of mandibular first molars were enlarged up to ProTaper NEXT X5 rotary instrument 2 mm beyond the apical foramen, simulating apical perforations. Specimens were randomly divided into four experimental groups (20 canals per group) according to the material and technique used for root canal obturation: BR/SC, BR/SC with ultrasonic agitation (BR/SC-UA), MF and MF with ultrasonic agitation (MF-UA). The ultrasonic tip was passively inserted into the root canal after the injection of flowable cement and activated for 10 s. The specimens were scanned before and after obturation with a high-resolution micro-computed tomography scanner, and the porosity of the apical plugs was assessed. The differences between groups were analyzed using the Kruskal-Wallis and Mann-Whitney tests, with the significance level set at 5%. None of the obturation materials and techniques used in this study was able to provide a pore-free root canal filling in the apical 5 mm. Considerably higher percentages of open and closed pores were observed in the MF and MF-UA groups, with the highest porosity being in the MF-UA group (p < 0.05). No significant differences were observed between the BR/SC and BR/SC-UA groups, where the quantity of open and closed pores remained similar (p > 0.05).
Collapse
|
5
|
Drukteinis S, Bilvinaite G, Tusas P, Shemesh H, Peciuliene V. Porosity Distribution in Single Cone Root Canal Fillings Performed by Operators with Different Clinical Experience: A microCT Assessment. J Clin Med 2021; 10:jcm10122569. [PMID: 34200692 PMCID: PMC8230067 DOI: 10.3390/jcm10122569] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 01/15/2023] Open
Abstract
The objective of this study was to assess the porosity distribution of BioRoot RCS/single gutta-percha point root-canal fillings performed by a general dental practitioner and endodontist. Fourteen plastic models of maxillary premolars with two roots were selected and shaped with HyFlex EDM instruments to a size 40/0.04 taper and randomly divided into two experimental groups. A total of 14 canals in each group were obturated by two different operators with one HyFlex EDM size 40 gutta-percha point and BioRoot RCS sealer. The specimens were scanned with a high-resolution micro-computed tomography scanner, and the porosity of the fillings at the coronal, middle, and apical thirds of the root canals was qualified and quantified. The differences between groups and root-canal thirds were compared using Mann–Whitney, Friedman, and Wilcoxon tests with the significance level set at p < 0.05. The highest number of pores was observed in the apical third of root-canal fillings in both groups; however, the porosity distribution between the two groups was not significantly different in the apical and middle thirds (p > 0.05). Statistically significant differences were determined only in the coronal third (p < 0.05). The predominance of open pores was detected in all root-canal thirds and groups, with no significant differences in the number of open pores between the coronal and middle thirds (p > 0.05).
Collapse
Affiliation(s)
- Saulius Drukteinis
- Institute of Dentistry Faculty of Medicine Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
- Correspondence: ; Tel.: +370-610-41808
| | - Goda Bilvinaite
- Institute of Dentistry Faculty of Medicine Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
| | - Paulius Tusas
- Institute of Dentistry Faculty of Medicine Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
| | - Hagay Shemesh
- Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3044, 1081 LA Amsterdam, The Netherlands;
| | - Vytaute Peciuliene
- Institute of Dentistry Faculty of Medicine Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
| |
Collapse
|
6
|
Effects of Ultrasonic Activation on Root Canal Filling Quality of Single-Cone Obturation with Calcium Silicate-Based Sealer. MATERIALS 2021; 14:ma14051292. [PMID: 33800442 PMCID: PMC7962949 DOI: 10.3390/ma14051292] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/01/2021] [Accepted: 03/05/2021] [Indexed: 11/29/2022]
Abstract
Background: We evaluated the effects of ultrasonic activation on root canal filling quality of the single-cone (SC) obturation technique with calcium silicate sealers and gutta percha cones. Methods: Thirty-six human single-rooted premolars were obturated with gutta percha and sealer. For the continuous wave (CW) group (n = 12), AH Plus with a continuous wave technique was used. The SC group (n = 12) received EndoSequence BC sealer with a single-cone technique. The SCU (SC with the addition of ultrasonic activation) group (n = 12) received the same treatment. Micro-computed tomography was used to scan the teeth, and the void volume within the root canal was evaluated at the apical, middle, and coronal levels. Then cross-sections were observed under a light microscope and scanning electron microscope (SEM). Results: Void volume was significantly lower in the SCU group than in the CW and SC groups. There were no statistically significant differences between the CW and SC groups. The SCU group had fewer voids than the CW and SC groups in the coronal and middle third areas. Specimens showed no apparent gaps or voids in any group. SEM images revealed both gap-free and gap-containing regions at different levels in all groups. Conclusions: Single-cone obturation with calcium silicate-based sealers might obtain enhanced filling quality when used with ultrasonic activation.
Collapse
|
7
|
Drukteinis S, Bilvinaite G, Tusas P, Shemesh H, Peciuliene V. Microcomputed Tomographic Assessment of the Single Cone Root Canal Fillings Performed by Undergraduate Student, Postgraduate Student and Specialist Endodontist. J Clin Med 2021; 10:jcm10051080. [PMID: 33807655 PMCID: PMC7961753 DOI: 10.3390/jcm10051080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/02/2021] [Accepted: 03/04/2021] [Indexed: 12/16/2022] Open
Abstract
The present study evaluated the obturation quality of root canals filled with BioRoot RCS sealer and single gutta-percha point by undergraduate student (US), postgraduate student (PS) and endodontist (ED). Twenty-one plastic models of upper premolars were enlarged with HyFlex EDM instruments to a size 40/0.04 taper and randomly divided into three groups (7 teeth/14 canals per group): US, PS and ED. After the obturation of root canals with BioRoot RCS and one HyFlex EDM size 40 gutta-percha point, plastic models were scanned using micro-computed tomography scanner (µCT) SkyScan 1272 at isotropic resolution of 10 µm. The porosity distribution was evaluated separately for the apical, middle and coronal thirds. The Kruskal–Wallis, Mann–Whitney, Friedman and Wilcoxon tests with the significance level set at 5% were used for data analysis. The µCT evaluation revealed open pores being the dominant type of porosity in all experimental groups and root canal thirds, with the highest percentage of pores in the apical third of root canal fillings. The quality and homogeneity of single cone root canals fillings remained similar between the groups in the apical and middle thirds (p > 0.05). Significant differences were observed only in the coronal third (p < 0.05).
Collapse
Affiliation(s)
- Saulius Drukteinis
- Institute of Dentistry, Faculty of Medicine, Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
- Correspondence: ; Tel.: +370-610-41808
| | - Goda Bilvinaite
- Institute of Dentistry, Faculty of Medicine, Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
| | - Paulius Tusas
- Institute of Dentistry, Faculty of Medicine, Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
| | - Hagay Shemesh
- Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3044, 1081 LA Amsterdam, The Netherlands;
| | - Vytaute Peciuliene
- Institute of Dentistry, Faculty of Medicine, Vilnius University, Zalgirio 115, LT-08217 Vilnius, Lithuania; (G.B.); (P.T.); (V.P.)
| |
Collapse
|
8
|
Zhong X, Shen Y, Ma J, Chen WX, Haapasalo M. Quality of Root Filling after Obturation with Gutta-percha and 3 Different Sealers of Minimally Instrumented Root canals of the Maxillary First Molar. J Endod 2019; 45:1030-1035. [PMID: 31182216 DOI: 10.1016/j.joen.2019.04.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 04/04/2019] [Accepted: 04/18/2019] [Indexed: 11/29/2022]
Abstract
INTRODUCTION The aim of this study was to compare the quality of root fillings completed by a modified single-cone (MSC) technique with 3 different sealers after minimal instrumentation and multisonic cleaning of root canals of maxillary first molars. METHODS Root canals of 18 maxillary first molars were instrumented to size 15/.04 taper using rotary files. Sodium hypochlorite 5.25% was used during instrumentation; the final cleaning was performed by the GentleWave System (Sonendo Inc, Laguna Hills, CA). The specimens were allocated into 3 groups and root filled by the MSC technique using a size fitted gutta-percha master cone and GuttaFlow Bioseal (Coltene Whaledent GmBH + Co KG, Langenau, Switzerland), GuttaFlow 2 (Coltene Whaledent GmBH + Co KG), and MTA Fillapex (Angelus Industria de Produtos Odontológicos S/A, Londrina, PR, Brazil) sealers. Micro-computed tomographic scans were obtained before and after instrumentation, post-GentleWave, and after obturation. Reconstructed images were analyzed for the volumetric percentage of filling materials. Mesiobuccal roots of the selected teeth were sectioned at 0.5-mm increments starting at the apex of the root. The cross sections were further examined using a light microscope. RESULTS The 3 groups had 90%-99% of the canal space filled with the root filling material. The mean volume of the filling material was higher in the GuttaFlow Bioseal and GuttaFlow 2 groups than in the MTA Fillapex group (P < .05). There was no significant difference among the apical, middle, and coronal thirds. The cross-sectional images showed no obvious gaps or voids in the GuttaFlow groups. After instrumentation, 49 of the 189 canal thirds (25.9%) had hard tissue debris in the root canal system. After GentleWave cleaning, only 4 of 63 canals (6.3%) and 4 of the 189 canal thirds (2.1%) still had debris. CONCLUSIONS The MSC method with GuttaFlow 2 and GuttaFlow Bioseal sealers after multisonic cleaning of minimally instrumented molar canals resulted in high-quality root fillings. Multisonic cleaning of minimally instrumented molars seems to be effective in debris removal.
Collapse
Affiliation(s)
- Xiaoyi Zhong
- Department of Cariology and Endodontology, College and Hospital of Stomatology, Guangxi Medical University, Nanning, China; Faculty of Dentistry, Division of Endodontics, Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Ya Shen
- Faculty of Dentistry, Division of Endodontics, Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Jingzhi Ma
- Department of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wen-Xia Chen
- Department of Cariology and Endodontology, College and Hospital of Stomatology, Guangxi Medical University, Nanning, China.
| | - Markus Haapasalo
- Faculty of Dentistry, Division of Endodontics, Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, BC, Canada.
| |
Collapse
|
9
|
Orhan K, Jacobs R, Celikten B, Huang Y, de Faria Vasconcelos K, Nicolielo LFP, Buyuksungur A, Van Dessel J. Evaluation of Threshold Values for Root Canal Filling Voids in Micro-CT and Nano-CT Images. SCANNING 2018; 2018:9437569. [PMID: 30116470 PMCID: PMC6079325 DOI: 10.1155/2018/9437569] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
While several materials and techniques have been used to assess the quality of root canal fillings in micro-CT images, the lack of standardization in scanning protocols has produced conflicting results. Hence, the aim of this study was to determine a cutoff voxel size value for the assessment of root canal filling voids in micro-CT and nano-CT images. Twenty freshly extracted mandibular central incisors were used. Root canals were prepared with nickel titanium files to an ISO size 40/0.06 taper and then filled with a single cone (40/0.06 taper) and AH Plus sealer. The teeth were scanned with different voxel sizes with either micro-CT (5.2, 8.1, 11.2, and 16.73 μm) or nano-CT (1.5 and 5.0 μm) equipment. Images were reconstructed and analyzed with the NRecon and CTAn software. Void proportion and void volume were calculated for each tooth in the apical, middle, and coronal thirds of the root canal. Kruskal-Wallis and post hoc Mann-Whitney U tests were performed with a significance level of 5%. In micro-CT images, significantly different results were detected among the tested voxel sizes for void proportion and void volume, whereas no such differences were found in nano-CT images (p > 0.05). Micro-CT images showed higher void numbers over the entire root length, with statistically significant differences between the voxel size of 16.73 μm and the other sizes (p < 0.05). The values of the different nano-CT voxel sizes did not significantly differ from those of the micro-CT (5.2, 8.1, and 11.2 μm), except for the voxel size of 16.73 μm (p < 0.05). All tested voxel sizes enabled the detection of root canal filling voids except for the voxel size of 16.73 μm. Bearing in mind the limitations of this study, it seems that a voxel size of 11.2 μm can be used as a reliable cutoff value for the assessment of root canal filling voids in micro-CT imaging.
Collapse
Affiliation(s)
- Kaan Orhan
- Faculty of Dentistry, Department of Dentomaxillofacial Radiology, Ankara University, Ankara, Turkey
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Reinhilde Jacobs
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
- Oral Facial Diagnostics and Surgery, Department of Dental Medicine, Karolinska Institutet, Solna, Sweden
| | - Berkan Celikten
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
- Faculty of Dentistry, Department of Endodontics, Ankara University, Ankara, Turkey
| | - Yan Huang
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
- State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, China
| | - Karla de Faria Vasconcelos
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil
| | - Laura Ferreira Pinheiro Nicolielo
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | | | - Jeroen Van Dessel
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| |
Collapse
|
10
|
Evaluation of the interface between gutta-percha and two types of sealers using scanning electron microscopy (SEM). Clin Oral Investig 2017; 22:1631-1639. [DOI: 10.1007/s00784-017-2216-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/21/2017] [Indexed: 10/18/2022]
|