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De-Deus G, Arashiro FN, Souza EM, Silva EJNL, Guimarães TDM, Maciel ACDC, Oliveira DDS, Belladonna FG, Lopes RT, Versiani MA. The impact of long-term storage conditions on the development of experimental dentinal microcracks. AUST ENDOD J 2024; 50:60-68. [PMID: 37876340 DOI: 10.1111/aej.12806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 07/27/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
This study evaluated the impact of long-term storage conditions (medium and time) on the development of experimental dentinal microcracks through micro-computed tomography. Sixty freshly extracted premolars were stored in formalin, water, or dry conditions (n = 20) and scanned after 72 h, 30 days, 6 months and 3 years of extraction. The effect of the storage medium and time on the occurrence of dentinal defects was statistically evaluated. A total of 211 000 images were screened revealing the existence of 11 519 slices with dentinal defects. Dry conditions significantly contributed to the development of new defects in all time points. During the 3-year follow-up period, no new defects were detected in the teeth that were stored in water and, in a single tooth, in the formalin group, after 6 months of storage.
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Affiliation(s)
- Gustavo De-Deus
- Department of Endodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Fabio Nakao Arashiro
- Department of Endodontics, School of Dentistry Federal University of Mato Grosso do Sul, Campo Grande, Brazil
| | - Erick Miranda Souza
- Department of Dentistry II, Federal University of Maranhão, São Luís, Maranhão, Brazil
| | - Emmanuel João Nogueira Leal Silva
- Department of Endodontics, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
- Department of Endodontics, Grande Rio University, Duque de Caxias, Rio de Janeiro, Brazil
| | | | | | | | | | - Ricardo Tadeu Lopes
- Nuclear Engineering Program, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marco Aurélio Versiani
- Dental Specialty Center, Brazilian Military Police, Belo Horizonte, Minas Gerais, Brazil
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Xu J, Chen Y, Zhou M, Yi S, Ran J, Liu J, Chi J, Chen Z, Tian K. Effects of cryopreservation on the biomechanical properties of dentin in cryopreserved teeth: An in-vitro study. Cryobiology 2023:S0011-2240(23)00031-7. [PMID: 37121387 DOI: 10.1016/j.cryobiol.2023.04.002] [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: 11/02/2022] [Revised: 03/22/2023] [Accepted: 04/21/2023] [Indexed: 05/02/2023]
Abstract
This study focused on the biomechanical properties and microstructural changes in dentin of teeth in different age groups after cryopreserved for different durations. Ninety third molars from three age groups (youth group, middle-age group, and elderly group), were collected and randomly divided into three groups according to freezing time at -196 °C (7 days, 30 days, and 90 days). Control group was shored at ordinary temperature. After rewarming, the compressive strength and elastic modulus of the dentin were measured with an electronic universal tester. Scanning electron microscopy was used to evaluate the microstructure of dentin after cryopreservation. After cryopreservation, the compressive strength of the teeth in each experimental group was not significantly different from control group. With the increase of freezing time and age, dentin's elastic modulus showed a decreasing trend. There were statistically significances between the control group and freezing 90d group, freezing 7d and 90d group, youth and middle-aged group, youth and elderly group (P < 0.05). Both freezing time and age factors were significant for the elastic modulus of dentin(P<0.05). There was no interaction effect for age and freezing time. In transverse sections of scanning electron microscopy, the dentinal tubule became narrower, partially occluded, and more easily adhered to impurities in the long freezing time and elderly group. In longitudinal sections, with freezing time and age, the inner wall of the dentinal tubules became rough especially in the aged group cryopreserved for 90 days. No significant microcracks exited in any of the longitudinal sections of dentin.
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Affiliation(s)
- Juan Xu
- School of Stomatology, Southwest Medical University, Luzhou, 646000, China; Department of Stomatology, China Railway No.2 Group Hospital, Chengdu, 610000, China.
| | - Yue Chen
- School of Stomatology, Southwest Medical University, Luzhou, 646000, China
| | - Min Zhou
- Department of Stomatology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Shouyin Yi
- School of Stomatology, Southwest Medical University, Luzhou, 646000, China
| | - Juan Ran
- School of Stomatology, Zunyi Medical College, Zunyi, 563000, China
| | - Juanxiu Liu
- Department of Stomatology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Junzhou Chi
- School of Stomatology, Southwest Medical University, Luzhou, 646000, China
| | - Zhu Chen
- Operative Dentistry&Endodontics, Guiyang Stomatological Hospital, Guiyang, 550002, Guizhou, China
| | - Kun Tian
- School of Stomatology, Southwest Medical University, Luzhou, 646000, China; Department of Stomatology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
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Neelakantan P, Vishwanath V, Taschieri S, Corbella S. Present status and future directions ‐ Minimally invasive root canal preparation and periradicular surgery. Int Endod J 2022; 55 Suppl 4:845-871. [DOI: 10.1111/iej.13750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 04/06/2022] [Accepted: 04/11/2022] [Indexed: 11/30/2022]
Affiliation(s)
- P. Neelakantan
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - V. Vishwanath
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - S. Taschieri
- Department of Biomedical Surgical and Dental Sciences Università degli Studi di Milano Milan Italy
- IRCCS Istituto Ortopedico Galeazzi Milan Italy
- Department of Oral Surgery Institute of Dentistry I. M. Sechenov First Moscow State Medical University Moscow Russia
| | - S. Corbella
- Department of Biomedical Surgical and Dental Sciences Università degli Studi di Milano Milan Italy
- IRCCS Istituto Ortopedico Galeazzi Milan Italy
- Department of Oral Surgery Institute of Dentistry I. M. Sechenov First Moscow State Medical University Moscow Russia
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Patel S, Bhuva B, Bose R. Vertical root fractures in root treated teeth-current status and future trends. Int Endod J 2022; 55 Suppl 3:804-826. [PMID: 35338655 PMCID: PMC9324143 DOI: 10.1111/iej.13737] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 11/28/2022]
Abstract
Vertical root fracture (VRF) is a common reason for the extraction of root filled teeth. The accurate diagnosis of VRF may be challenging due to the absence of clinical signs, whilst conventional radiographic assessment is often inconclusive. However, an understanding of the aetiology of VRFs, and more importantly, the key predisposing factors, is crucial in identifying teeth that may be susceptible. Thorough clinical examination with magnification and co-axial lighting is essential in identifying VRFs, and although CBCT is unable to reliably detect VRFs per se, the pattern of bone loss typically associated with VRF can be fully appreciated, and therefore, increases the probability of correct diagnosis and management. The prevalence of VRFs in root filled teeth is significantly greater than in teeth with vital pulps, demonstrating that the combination of loss of structural integrity, presence of pre-existing fractures and biochemical effects of loss of vitality, are highly relevant. Careful assessment of the occlusal scheme, presence of deflective contacts and identification of parafunctional habits is imperative in both preventing and managing VRFs. Furthermore, anatomical factors such as root canal morphology, may predispose certain teeth to VRF. The influence of access cavity design and root canal instrumentation protocols should be considered although the impact of these on the fracture resistance of root filled teeth is not clearly validated. The post-endodontic restoration of root filled teeth should be expedient and considerate to the residual tooth structure. Posts should be placed 'passively' and excessive 'post-space' preparation should be avoided. This narrative review aims to present the aetiology, potential predisposing factors, histopathology, diagnosis and management of VRF and present perspectives for future research. Currently, there are limited options other than extraction for the management of VRF, although root resection may be considered in multi-rooted teeth. Innovative techniques to 'repair' VRFs using both orthograde and surgical approaches require further research and validation. The prevention of VRFs is critical; identifying susceptible teeth, utilizing conservative endodontic procedures, together with expedient and appropriate post-endodontic restorative procedures is paramount to reducing the incidence of terminal VRFs.
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Affiliation(s)
- Shanon Patel
- Department of Endodontology, King's College London Dental Institute, London, UK.,Specialist Practice, London, UK
| | - Bhavin Bhuva
- Department of Endodontology, King's College London Dental Institute, London, UK
| | - Raul Bose
- Department of Endodontology, King's College London Dental Institute, London, UK
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Hülsmann M. A critical appraisal of research methods and experimental models for studies on root canal preparation. Int Endod J 2021; 55 Suppl 1:95-118. [PMID: 34800299 DOI: 10.1111/iej.13665] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 11/17/2021] [Indexed: 01/02/2023]
Abstract
It is the aim of this review to present a critical overview and summary on the contemporary possibilities, limitations and challenges of research related to root canal preparation. Frequently used research tools and contemporary research designs will be presented and discussed critically focussing on shortcomings and benefits with special regard to clinical relevance and scientific evidence. A plethora of experimental set-ups for assessing the shaping of root canals have been described in the endodontic literature using a considerable number of techniques and instruments. Nevertheless, it can be stated that scientific evidence demonstrating the clinical impact of many investigated topics is questionable or even missing. Instead of technical, radiographic and geometrical parameters, further research should focus on biological aspects and clinical evidence of the impact of root canal preparation on the outcome of root canal treatment.
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Affiliation(s)
- Michael Hülsmann
- Clinic of Conservative and Preventive Dentistry, University of Zurich, Zurich, Switzerland
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Versiani MA, Cavalcante DM, Belladonna FG, Silva EJNL, Souza EM, De-Deus G. A critical analysis of research methods and experimental models to study dentinal microcracks. Int Endod J 2021; 55 Suppl 1:178-226. [PMID: 34743355 DOI: 10.1111/iej.13660] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 12/30/2022]
Abstract
The purpose of this narrative review was to discuss the scientific milestones that led to the current understanding of the root dentinal microcrack phenomenon based on the interplay between the usage of micro-computed tomography (micro-CT) as an analytical tool alongside a close-to-mouth experimental model. In 2009, reports on the development of dentinal microcracks in extracted teeth after root canal preparation triggered an awareness of the potential for vertical root fractures (VRFs) of endodontically treated teeth could be developed from defects created by the mechanical stress of nickel-titanium preparation systems on dentine. This assumption was taken for granted, even though no cause-effect relationship had been scientifically demonstrated. Since then, several studies using the sectioning method with extracted teeth have been published and the large discrepancy amongst their outcomes soon become evident. Moreover, the high frequency of reported dentinal microcracks largely contrasted with the clinical incidence of VRFs, raising doubts on their methodological reliability. Using micro-CT technology, it was demonstrated by several studies that, in extracted teeth, dentinal defects already existed before the endodontic procedures, indicating that the initial reports framed a non-existing cause-effect relationship between canal preparation and dentinal microcracks. Although these new findings contributed to a better comprehension of this phenomenon, the misconception that microcracks were the starting point for VRFs was only surpassed with a new in situ approach using fresh cadavers. Surprisingly, microcracks were not identified in sound teeth. As a conclusion, dentinal microcracks in extracted teeth can be considered a non-natural occurrence observed only in a laboratory set-up as a consequence of dehydration and storage conditions. Thus, dentinal microcracks shall not be considered as the starting point for VRFs as they do not manifest in non-extracted teeth. Identifying dentinal microcracks as a laboratory phenomenon highlights the impact of recent scientific developments to disclaim the clinical relevance of laboratory-obtained outcomes.
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Affiliation(s)
| | | | | | - Emmanuel João Nogueira Leal Silva
- Department of Endodontics, Fluminense Federal University, Niterói, Brazil.,Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Duque de Caxias, Brazil
| | - Erick Miranda Souza
- Department of Dentistry II, Federal University of Maranhão, São Luís, Brazil
| | - Gustavo De-Deus
- Department of Endodontics, Fluminense Federal University, Niterói, Brazil
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