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Wang JS, Bai W, Wang Y, Liang YH. Effect of different dentin moisture on the push-out strength of bioceramic root canal sealer. J Dent Sci 2023; 18:129-134. [PMID: 36643254 PMCID: PMC9831826 DOI: 10.1016/j.jds.2022.06.025] [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: 04/12/2022] [Revised: 06/27/2022] [Indexed: 01/18/2023] Open
Abstract
Background/purpose Different moisture condition may affect the adhesion between obturation materials and root canal walls, thus further affect the quality of root canal obturation. The aim of this study was to evaluate the influence of dentin moisture conditions after different root canal drying protocols on the push-out strength of bioceramic root canal sealer. Materials and methods Twenty root canals from extracted human decoronated premolars were prepared in vitro to #30/0.09 taper and assigned to 4 moisture condition groups after using different root canal drying protocols: normal moisture (paper point) group: the canals were blot dried with paper points until the last one appeared dry. Ethanol dry group: the canals were dried with paper points followed by dehydration with 95% ethanol. Isopropanol dry group: the canals were dried with paper points followed by dehydration with 70% isopropanol. Complete dry group: the canals were dried in an air-blowing thermostatic oven for at least 6 h until there was no change in weight at an interval of 1 h. After drying, the canals were obturated with bioceramic sealer iRoot SP. Then, each root was sectioned into eight slices with 1-mm-thick using a diamond saw (40 slices each group). The push-out strength was tested for each slice between the sealer and dentin wall using a universal testing machine at a crosshead speed of 0.5 mm/min, and failure modes were recorded. Two-way analysis of variance and Tukey test were used to analyze the push-out strength. Logarithmic linear regression analysis was used to compare the failure modes. Results Push-out strength was statistically different in different moisture groups (P < 0.05). After drying using paper point, iRoot SP specimens showed the highest push-out strength (2.04 ± 0.03 MPa), followed by 95% ethanol, 70% isopropanol. The lowest push-out strength (0.68 ± 0.04 MPa) was observed under complete dry. For the failure modes, the majority were cohesive failures in the coronal and middle thirds of the root; while in the apical third, mixed failure was common. Conclusion Different drying protocols influenced the push-out strength between bioceramic sealer and canal wall.
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Affiliation(s)
- Jia-Sha Wang
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology, Beijing, China,Dental Center, China-Japan Friendship Hospital, Beijing, China
| | - Wei Bai
- Department of Dental Material Laboratory, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Yue Wang
- Department of Stomatology, Peking University International Hospital, Beijing, China
| | - Yu-Hong Liang
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology, Beijing, China,Department of Stomatology, Peking University International Hospital, Beijing, China,Corresponding author. Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology, Beijing, China.
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Durand JC, Slangen P, Montresor S, Desoutter A, Solieman OY, Fages M, Picart P. Behavior of CAD/CAM ceramic veneers under stress: A 3D holographic study. J Mech Behav Biomed Mater 2021; 118:104436. [PMID: 33761374 DOI: 10.1016/j.jmbbm.2021.104436] [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: 11/16/2020] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVES Ceramic veneers restorations may undergo damages, such as cracks, fractures, or debonding. Full-field measurements must be carried out in order to visualize and analyze the strain fields. This paper demonstrates that digital holography permits to investigate the mechanical behavior under stress of a natural incisor and a natural incisor reconstructed with CAD/CAM ceramic veneer. METHODS The facial surface of a maxillary central incisor is prepared to receive a monolithic ceramic reconstruction manufactured using a chairside computer-aided design and computer aided manufacturing (CAD/CAM) system (Cerec AC® system, Sirona Dental System®, Bensheim, Germany). One incisor is kept intact for comparison. The samples are sectioned longitudinally to obtain a planar observation of the region of interest. A mechanical indentation head and digital holographic set-ups permit a full-field, contact-less and single-shot measurement of the three-dimensional displacement fields at the surface of the tooth sample when subjected to load. Stain fields are then estimated and comparison of the results between two samples can be carried out. RESULTS 3D displacement, fields and strain fields are measured and highlight the behavior of the region of interest in three directions of space for the ceramic veneer and the natural incisor. The strain maps reveal the local behavior, especially the concentration or the sudden change in strain. The transition zones are clearly observed, particularly for the veneered sample. CONCLUSION Digital holography highlights the localization of stress concentration zones in regions of interest and yields comparative analysis between samples with different tooth preparations. SIGNIFICANCE holography permits to visualize and compare the mechanical response of the ceramic veneer and natural tooth. This helps choosing the mechanical properties of the bonding interface.
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Affiliation(s)
- J-C Durand
- Laboratoire Bioingenierie et Nanosciences, LBN UR-UM104, Université de Montpellier, 545 Avenue du Professeur Jean Louis Viala, 34193, Montpellier Cedex 5, France; Department of Prosthetic Dentistry, Faculty of Odontology, Montpellier University, 545 Avenue du Professeur Jean Louis Viala, 34193, Montpellier Cedex 5, France.
| | - P Slangen
- EuroMov Digital Health in Motion, Univ Montpellier, IMT Mines Ales, Ales, France.
| | - S Montresor
- Le Mans Université, CNRS UMR 6613, LAUM, Avenue Olivier Messiaen, 72085, Le Mans Cedex 9, France.
| | - A Desoutter
- Laboratoire Bioingenierie et Nanosciences, LBN UR-UM104, Université de Montpellier, 545 Avenue du Professeur Jean Louis Viala, 34193, Montpellier Cedex 5, France.
| | - O Y Solieman
- Laboratoire Bioingenierie et Nanosciences, LBN UR-UM104, Université de Montpellier, 545 Avenue du Professeur Jean Louis Viala, 34193, Montpellier Cedex 5, France.
| | - M Fages
- Laboratoire Bioingenierie et Nanosciences, LBN UR-UM104, Université de Montpellier, 545 Avenue du Professeur Jean Louis Viala, 34193, Montpellier Cedex 5, France; Department of Prosthetic Dentistry, Faculty of Odontology, Montpellier University, 545 Avenue du Professeur Jean Louis Viala, 34193, Montpellier Cedex 5, France.
| | - P Picart
- Le Mans Université, CNRS UMR 6613, LAUM, Avenue Olivier Messiaen, 72085, Le Mans Cedex 9, France.
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Erİk CE, Kaya BÜ, Maden M, Orhan EO. Influence of sodium hypochlorite/etidronic acid combination and SmearOFF on push-out bond strength of fiber posts to root dentin. Dent Mater J 2020; 39:554-562. [PMID: 32161238 DOI: 10.4012/dmj.2019-055] [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] [Indexed: 11/23/2022]
Abstract
The aim was to evaluate the effects of different irrigation protocols on the bonding ability of fiber posts on root canal dentin through push-out test and the dentin tubule penetration of luting cement by confocal laser scanning microscope (CLSM). Forty-eight single-rooted premolars were divided into six groups (n=8) based on post space irrigation protocols: Saline 0.85%; Etidronate 18% (HEBP); EDTA 17%; NaOCl 5.25%+EDTA 17%; NaOCl 2.5%/HEBP 9% combination; SmearOFF. Two specimens per group were assessed with CLSM. The push-out test and the failure analysis were performed. Whilst EDTA had the highest bond strength at the coronal and middle thirds, it was not statistically significant compared to saline, HEBP, and NaOCl/HEBP at the middle third (p>0.05). Cement/dentin adhesive failures were predominant (41.9%) and the intratubular fluorescence intensity was significant among the groups (p<0.05). EDTA resulted in highest bond strength values and dentinal penetration.
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Affiliation(s)
- Cevat Emre Erİk
- Department of Endodontics, Faculty of Dentistry, Suleyman Demirel University
| | - Bulem Üreyen Kaya
- Department of Endodontics, Faculty of Dentistry, Suleyman Demirel University
| | - Murat Maden
- Department of Endodontics, Faculty of Dentistry, Suleyman Demirel University
| | - Ekim Onur Orhan
- Department of Endodontics, Faculty of Dentistry, Osmangazi University
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Chen Z, Nadeau B, Yu K, Shao X, He X, Goh MC, Kishen A. Whole-field macro- and micro-deformation characteristic of unbound water-loss in dentin hard tissue. JOURNAL OF BIOPHOTONICS 2018; 11:e201700368. [PMID: 29626390 DOI: 10.1002/jbio.201700368] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/03/2018] [Indexed: 06/08/2023]
Abstract
High-resolution deformation measurements in a functionally graded hard tissue such as human dentin are essential to understand the unbound water-loss mediated changes and their role in its mechanical integrity. Yet a whole-field, 3-dimensional (3D) measurement and characterization of fully hydrated dentin in both macro- and micro-scales remain to be a challenge. This study was conducted in 2 stages. In stage-1, a stereo-digital image correlation approach was utilized to determine the water-loss and load-induced 3D deformations of teeth in a sagittal section over consecutively acquired frames, from a fully hydrated state to nonhydrated conditions for a period up to 2 hours. The macroscale analysis revealed concentrated residual deformations at the dentin-enamel-junction and the apical regions of root in the direction perpendicular to the dentinal tubules. Significant difference in the localized deformation characteristics was observed between the inner and outer aspects of the root dentin. During quasi-static loadings, further increase in the residual deformation was observed in the dentin. In stage-2, dentin microstructural variations induced by dynamic water-loss were assessed with environmental scanning electron microscopy and atomic force microscopy (AFM), showing that the dynamic water-loss induced distention of dentinal tubules with concave tubular edges, and concurrent contraction of intertubular dentin with convex profile. The findings from the current macro- and micro-scale analysis provided insight on the free-water-loss induced regional deformations and ultrastructural changes in human dentin.
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Affiliation(s)
- Zhenning Chen
- Jiangsu Key Laboratory of Engineering Mechanics, Southeast University, Nanjing, Jiangsu, China
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Bobby Nadeau
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Kevin Yu
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Xinxing Shao
- Jiangsu Key Laboratory of Engineering Mechanics, Southeast University, Nanjing, Jiangsu, China
| | - Xiaoyuan He
- Jiangsu Key Laboratory of Engineering Mechanics, Southeast University, Nanjing, Jiangsu, China
| | - M Cynthia Goh
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Anil Kishen
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
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Xia H, Picart P, Montresor S, Guo R, Li J, Yusuf Solieman O, Durand JC, Fages M. Mechanical behavior of CAD/CAM occlusal ceramic reconstruction assessed by digital color holography. Dent Mater 2018; 34:1222-1234. [DOI: 10.1016/j.dental.2018.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/30/2018] [Accepted: 05/04/2018] [Indexed: 10/16/2022]
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Jang AT, Chen L, Shimotake AR, Landis W, Altoe V, Aloni S, Ryder M, Ho SP. A Force on the Crown and Tug of War in the Periodontal Complex. J Dent Res 2018; 97:241-250. [PMID: 29364757 DOI: 10.1177/0022034517744556] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The load-bearing dentoalveolar fibrous joint is composed of biomechanically active periodontal ligament (PDL), bone, cementum, and the synergistic entheses of PDL-bone and PDL-cementum. Physiologic and pathologic loads on the dentoalveolar fibrous joint prompt natural shifts in strain gradients within mineralized and fibrous tissues and trigger a cascade of biochemical events within the widened and narrowed sites of the periodontal complex. This review highlights data from in situ biomechanical simulations that provide tooth movements relative to the alveolar socket. The methods and subsequent results provide a reasonable approximation of strain-regulated biochemical events resulting in mesial mineral formation and distal resorption events within microanatomical regions at the ligament-tethered/enthesial ends. These biochemical events, including expressions of biglycan, decorin, chondroitin sulfated neuroglial 2, osteopontin, and bone sialoprotein and localization of various hypertrophic progenitors, are observed at the alkaline phosphatase-positive widened site, resulting in mineral formation and osteoid/cementoid layers. On the narrowed side, tartrate-resistant acid phosphatase regions can lead to a sequence of clastic activities resulting in resorption pits in bone and cementum. These strain-regulated biochemical and subsequently biomineralization events in the load-bearing periodontal complex are critical for maintenance of the periodontal space and overall macroscale joint biomechanics.
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Affiliation(s)
- A T Jang
- 1 Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - L Chen
- 1 Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - A R Shimotake
- 1 Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - W Landis
- 1 Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - V Altoe
- 2 Materials Science Division, The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - S Aloni
- 2 Materials Science Division, The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - M Ryder
- 3 Division of Periodontics, Department of Orofacial Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - S P Ho
- 1 Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.,4 Department of Urology, School of Medicine, University of California San Francisco, San Francisco, CA, USA
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7
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New Trends in Dental Biomechanics with Photonics Technologies. APPLIED SCIENCES-BASEL 2015. [DOI: 10.3390/app5041350] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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8
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Biomechanics and strain mapping in bone as related to immediately-loaded dental implants. J Biomech 2015; 48:3486-94. [PMID: 26162549 DOI: 10.1016/j.jbiomech.2015.05.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 04/20/2015] [Accepted: 05/14/2015] [Indexed: 11/24/2022]
Abstract
The effects of alveolar bone socket geometry and bone-implant contact on implant biomechanics, and resulting strain distributions in bone were investigated. Following extraction of lateral incisors on a cadaver mandible, implants were placed immediately and bone-implant contact area, stability implant biomechanics and bone strain were measured. In situ biomechanical testing coupled with micro X-ray microscopy (µ-XRM) illustrated less stiff bone-implant complexes (701-822 N/mm) compared with bone-periodontal ligament (PDL)-tooth complexes (791-913 N/mm). X-ray tomograms illustrated that the cause of reduced stiffness was due to limited bone-implant contact. Heterogeneous elemental composition of bone was identified by using energy dispersive X-ray spectroscopy (EDS). The novel aspect of this study was the application of a new experimental mechanics method, that is, digital volume correlation, which allowed mapping of strains in volumes of alveolar bone in contact with a loaded implant. The identified surface and subsurface strain concentrations were a manifestation of load transferred to bone through bone-implant contact based on bone-implant geometry, quality of bone, implant placement, and implant design. 3D strain mapping indicated that strain concentrations are not exclusive to the bone-implant contact regions, but also extend into bone not directly in contact with the implant. The implications of the observed strain concentrations are discussed in the context of mechanobiology. Although a plausible explanation of surgical complications for immediate implant treatment is provided, extrapolation of results is only warranted by future systematic studies on more cadaver specimens and/or in vivo models.
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9
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Grandfield K, Chattah NLT, Djomehri S, Eidelmann N, Eichmiller FC, Webb S, Schuck PJ, Nweeia M, Ho SP. The narwhal (Monodon monoceros) cementum-dentin junction: a functionally graded biointerphase. Proc Inst Mech Eng H 2015; 228:754-67. [PMID: 25205746 DOI: 10.1177/0954411914547553] [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] [Indexed: 11/16/2022]
Abstract
In nature, an interface between dissimilar tissues is often bridged by a graded zone, and provides functional properties at a whole organ level. A perfect example is a "biological interphase" between stratified cementum and dentin of a narwhal tooth. This study highlights the graded structural, mechanical, and chemical natural characteristics of a biological interphase known as the cementum-dentin junction layer and their effect in resisting mechanical loads. From a structural perspective, light and electron microscopy techniques illustrated the layer as a wide 1000-2000 μm graded zone consisting of higher density continuous collagen fiber bundles from the surface of cementum to dentin, that parallels hygroscopic 50-100 μm wide collagenous region in human teeth. The role of collagen fibers was evident under compression testing during which the layer deformed more compared to cementum and dentin. This behavior is reflected through site-specific nanoindentation indicating a lower elastic modulus of 2.2 ± 0.5 GPa for collagen fiber bundle compared to 3 ± 0.4 GPa for mineralized regions in the layer. Similarly, microindentation technique illustrated lower hardness values of 0.36 ± 0.05 GPa, 0.33 ± 0.03 GPa, and 0.3 ± 0.07 GPa for cementum, dentin, and cementum-dentin layer, respectively. Biochemical analyses including Raman spectroscopy and synchrotron-source microprobe X-ray fluorescence demonstrated a graded composition across the interface, including a decrease in mineral-to-matrix and phosphate-to-carbonate ratios, as well as the presence of tidemark-like bands with Zn. Understanding the structure-function relationships of wider tissue interfaces can provide insights into natural tissue and organ function.
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Affiliation(s)
- Kathryn Grandfield
- Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Netta Lev-Tov Chattah
- Division of Identification and Forensic Sciences, Israel National Police, Jerusalem, Israel
| | - Sabra Djomehri
- Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Naomi Eidelmann
- Paffenbarger Research Center, American Dental Association Foundation, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | - Samuel Webb
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - P James Schuck
- Materials Science Division, The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Martin Nweeia
- Department of Vertebrate Zoology, Smithsonian Institution, Washington, DC, USA
| | - Sunita P Ho
- Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, CA, USA
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Moinzadeh AT, Jongsma LA, Wesselink PR. Considerations about the use of the “push-out” test in Endodontic research. Int Endod J 2015; 48:498-500. [DOI: 10.1111/iej.12416] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. T. Moinzadeh
- Departments of Endodontology; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
| | - L. A. Jongsma
- Departments of Dental Material Science; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
| | - P. R. Wesselink
- Departments of Endodontology; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
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11
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Biomechanics of a bone-periodontal ligament-tooth fibrous joint. J Biomech 2012; 46:443-9. [PMID: 23219279 DOI: 10.1016/j.jbiomech.2012.11.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/30/2012] [Accepted: 11/02/2012] [Indexed: 12/23/2022]
Abstract
This study investigates bone-tooth association under compression to identify strain amplified sites within the bone-periodontal ligament (PDL)-tooth fibrous joint. Our results indicate that the biomechanical response of the joint is due to a combinatorial response of the constitutive properties of organic, inorganic, and fluid components. Second maxillary molars within intact maxillae (N=8) of 5-month-old rats were loaded with a μ-XCT-compatible in situ loading device at various permutations of displacement rates (0.2, 0.5, 1.0, 1.5, 2.0 mm/min) and peak reactionary load responses (5, 10, 15, 20 N). Results indicated a nonlinear biomechanical response of the joint, in which the observed reactionary load rates were directly proportional to displacement rates (velocities). No significant differences in peak reactionary load rates at a displacement rate of 0.2mm/min were observed. However, for displacement rates greater than 0.2mm/min, an increasing trend in reactionary rate was observed for every peak reactionary load with significant increases at 2.0mm/min. Regardless of displacement rates, two distinct behaviors were identified with stiffness (S) and reactionary load rate (LR) values at a peak load of 5 N (S(5 N)=290-523 N/mm) being significantly lower than those at 10 N (LR(5 N)=1-10 N/s) and higher (S(10 N-20 N)=380-684 N/mm; LR(10 N-20 N)=1-19 N/s). Digital image correlation revealed the possibility of a screw-like motion of the tooth into the PDL-space, i.e., predominant vertical displacement of 35 μm at 5 N, followed by a slight increase to 40 μm at 10 N and 50 μm at 20 N of the tooth and potential tooth rotation at loads above 10 N. Narrowed and widened PDL spaces as a result of tooth displacement indicated areas of increased apparent strains within the complex. We propose that such highly strained regions are "hot spots" that can potentiate local tissue adaptation under physiological loading and adverse tissue adaptation under pathological loading conditions.
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12
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Soons J, Lava P, Debruyne D, Dirckx J. Full-field optical deformation measurement in biomechanics: digital speckle pattern interferometry and 3D digital image correlation applied to bird beaks. J Mech Behav Biomed Mater 2012; 14:186-91. [PMID: 23026697 DOI: 10.1016/j.jmbbm.2012.05.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/02/2012] [Accepted: 05/06/2012] [Indexed: 12/01/2022]
Abstract
In this paper two easy-to-use optical setups for the validation of biomechanical finite element (FE) models are presented. First, we show an easy-to-build Michelson digital speckle pattern interferometer (DSPI) setup, yielding the out-of-plane displacement. We also introduce three-dimensional digital image correlation (3D-DIC), a stereo photogrammetric technique. Both techniques are non-contact and full field, but they differ in nature and have different magnitudes of sensitivity. In this paper we successfully apply both techniques to validate a multi-layered FE model of a small bird beak, a strong but very light biological composite. DSPI can measure very small deformations, with potentially high signal-to-noise ratios. Its high sensitivity, however, results in high stability requirements and makes it hard to use it outside an optical laboratory and on living samples. In addition, large loads have to be divided into small incremental load steps to avoid phase unwrapping errors and speckle de-correlation. 3D-DIC needs much larger displacements, but automatically yields the strains. It is more flexible, does not have stability requirements, and can easily be used as an optical strain gage.
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Affiliation(s)
- Joris Soons
- Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, B2020 Antwerpen, Belgium.
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González-Peña RJ, Salvador R, Cibrián RM, Martinez-Celorio RA, López FJ, Sala F, Paredes V. Effects of endodontic treatment on apparent Young's modulus of human teeth: in vitro study using speckle interferometry. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:048002. [PMID: 22559698 DOI: 10.1117/1.jbo.17.4.048002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The introduction of new techniques for endodontic procedures requires the analysis of the biomechanical behavior of dental structures. Digital speckle shearing pattern interferometry (DSSPI) is a nondestructive optical measuring technique that allows one to directly quantify deformations in teeth that are subjected to stress. DSSPI technique was applied to measure small deformations caused by flexion in different types of teeth. The test was carried out both before and after endodontic treatment with the ProTaper method in order to evaluate the variation of dental elasticity, taking into the account the type of tooth and the endodontic treatment. The results obtained show that dental elasticity, established by means of the apparent Young's modulus, before and after the endodontic treatment, differs between incisors and premolars. The endodontic process does not affect dental elasticity (p>0.7). Specifically, 57.1% of central incisors and 56.3% of second premolars slightly increase their elasticity after the endodontic process. In turn, 42.9% of central incisors and 43.7% of second premolars slightly decrease elasticity. The endodontic treatment especially affects the "neutral fibre"; therefore, there is little influence on elasticity by flexion. However, after finishing the process, the channel was restored with material, which can slightly increase tooth elasticity in some cases.
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Affiliation(s)
- Rolando J González-Peña
- Universidad de Valencia, Biofísica y Física Médica, Departamento Fisiología, Facultad de Medicina y Odontología.
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Chattah NLT, Kupczik K, Shahar R, Hublin JJ, Weiner S. Structure-function relations of primate lower incisors: a study of the deformation of Macaca mulatta dentition using electronic speckle pattern interferometry (ESPI). J Anat 2011; 218:87-95. [PMID: 20408905 PMCID: PMC3039783 DOI: 10.1111/j.1469-7580.2010.01234.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2010] [Indexed: 11/30/2022] Open
Abstract
Teeth adopt a variety of different morphologies, each of which is presumably optimized for performing specific functions during feeding. It is generally agreed that the enamel cap is a crucial element in controlling the mechanical behavior of mammalian teeth under load. Incisors are particularly interesting in terms of structure-function relations, as their role in feeding is that of the 'first bite'. However, little is known how incisor cap morphology is related to tooth deformation. In the present paper we examine the mechanical behavior of mandibular central incisors in the cercopithecine primate Macaca mulatta under loads similar to those encountered during ingestion. We map three-dimensional displacements on the labial surface of the crown as it is compressed, using electronic speckle pattern interferometry (ESPI), an optical metrology method. In addition, micro-computed tomography is used to obtain data regarding the morphology of the enamel cap, which in the M. mulatta lower incisors exhibits missing or very little enamel on the lingual face. The results showed that although compressed along a longitudinal axis, deformation in the incisors mostly occurred in the lingual direction and orthogonal to the direction of the applied load. Both isolated, embedded teeth and teeth in the mandible showed considerable lingual deformation. Incisor deformation in the mandible was generally greater, reflecting the additional freedom of movement enabled by the supporting structures. We show that the association with adjacent teeth in the arch is significant for the behavior of the tooth under load. Finally, loading two teeth simultaneously in the mandible showed that they work as one functional unit. We suggest that these results demonstrate the importance of enamel cap morphology in directing deformation behavior; an ability stemming from the stiffness of the enamel cap overlying the more pliable dentin.
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Abstract
STUDY DESIGN In vitro compressive load-displacement experiments on intact rat lumbar vertebrae and on the same vertebrae after part of their trabecular bone was removed. OBJECTIVE To determine the contribution of the trabecular bone component to the stiffness and strength of rat lumbar vertebrae. SUMMARY OF BACKGROUND DATA Vertebral fractures are common in the aging population, possibly resulting from the deterioration of the mechanical properties of vertebral bone. Studies of the contribution of trabecular bone to the mechanical behavior of whole vertebra were published, but yielded mixed results. Here, we propose a novel optical metrology approach to address this important question. METHODS The bodies of intact rat lumbar vertebrae and the bodies of the same vertebrae after part of their trabecular bone was removed were loaded within their elastic region in a wet environment. The amount of trabecular bone removed was determined by micro-computer tomography scanning. Deformation maps of the dorsal vertebral surface of the intact and manipulated vertebrae were obtained using an optical metrology method, and compared. Intact and manipulated vertebrae were also loaded to failure in compression and their strengths and stiffness were compared. RESULTS The preferred trabecular orientation was found to be along the anterior-posterior axis, which is similar to humans. Removal of up to 42% of the trabecular tissue in the intact vertebrae did not significantly affect lumbar vertebral stiffness. However, removal of even smaller amounts of the intact trabecular tissue significantly reduced vertebral strength. CONCLUSION Trabeculae in rat lumbar vertebrae fulfill an important role in failure resistance (strength), but have little or no effect on the deformational behavior (stiffness) of the bone. These results differ from previous results we reported for rat femora, where removal of trabecular bone surprisingly increased the stiffness of the whole bone, and suggest that trabecular tissue may have different functions depending on anatomic location, bone function and morphology, and mode of loading.
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Chattah NLT, Sharir A, Weiner S, Shahar R. Determining the elastic modulus of mouse cortical bone using electronic speckle pattern interferometry (ESPI) and micro computed tomography: a new approach for characterizing small-bone material properties. Bone 2009; 45:84-90. [PMID: 19332167 DOI: 10.1016/j.bone.2009.03.664] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 03/09/2009] [Accepted: 03/11/2009] [Indexed: 12/20/2022]
Abstract
Mice phenotypes are invaluable for understanding bone formation and function, as well as bone disease. The elastic modulus is an important property of bones that can provide insights into bone quality. The determination of the elastic modulus of mouse cortical bone is complicated by the small dimensions of the bones. Whole bone bending tests are known to under estimate the elastic modulus compared to nanoindentation tests. The latter however provides information on extremely localized areas that do not necessarily correspond to the bulk elastic modulus under compression. This study presents a novel method for determining the bulk or effective elastic modulus of mouse cortical bone using the femur. We use Electronic Speckle Pattern Interferometry (ESPI), an optical method that enables the measurement of displacements on the bone surface, as it is compressed under water. This data is combined with geometric information obtained from micro-CT to calculate the elastic modulus. Roughly tubular cortical bone segments (2 mm) were cut from the diaphyses of femora of four week old C57BL/6 (B6) female mice and compressed axially using a mechanical tension-compression device. Displacements in the loading direction were mapped on the bone surface after loading the specimen. A linear regression of the displacement vs. axial-position enabled the calculation of the effective strain. Effective stress was calculated using force (N) data from the system's load cell and the mean cross-sectional area of the sample as determined by micro-CT. The effective elastic modulus (E) was calculated from the stress to strain ratio. The method was shown to be accurate and precise using a standard material machined to similar dimensions as those of the mouse femoral segments. Diaphyses of mouse femora were shown to have mean elastic moduli of 10.4+/-0.9 GPa for femora frozen for eight months, 8.6+/-1.4 GPa for femora frozen for two weeks and 8.9+/-1.1 GPa for the fresh femora. These values are much higher than those measured using three-point bending, and lower than values reported in the literature based on nanoindentation tests from mice bones of the same age. We show that this method can be used to accurately and precisely measure the effective elastic modulus of mouse cortical bone.
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Gröning F, Liu J, Fagan M, O’Higgins P. Validating a voxel-based finite element model of a human mandible using digital speckle pattern interferometry. J Biomech 2009; 42:1224-9. [DOI: 10.1016/j.jbiomech.2009.03.025] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 03/11/2009] [Accepted: 03/11/2009] [Indexed: 11/15/2022]
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Barak MM, Sharir A, Shahar R. Optical metrology methods for mechanical testing of whole bones. Vet J 2009; 180:7-14. [DOI: 10.1016/j.tvjl.2007.11.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Revised: 10/31/2007] [Accepted: 11/24/2007] [Indexed: 11/27/2022]
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Are tensile and compressive Young’s moduli of compact bone different? J Mech Behav Biomed Mater 2009; 2:51-60. [DOI: 10.1016/j.jmbbm.2008.03.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 03/17/2008] [Accepted: 03/28/2008] [Indexed: 11/21/2022]
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Yao X, Wang P, Dai R. Experimental study of damage and fracture of cancellous bone using a digital speckle correlation method. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:034026. [PMID: 18601571 DOI: 10.1117/1.2928126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Cancellous bone is a widespread structure in a creatural body, for instance, in the femoral head and spondyle. The damage evolution and crack growth of cattle cancellous bone were studied under three-point-bending load conditions. A series of speckle images with deformation information surrounding the crack tip were recorded, and the full-field displacement distributions were obtained at different loading levels by means of digital speckle correlation method (DSCM). Characterizations of the damage deformation and fracture of cancellous bone were analyzed. These results provide some useful information for studying the fracture behavior of cancellous bone.
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Affiliation(s)
- Xuefeng Yao
- Tsinghua University, Department of Engineering Mechanics, Beijing 100084, China.
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Barak MM, Weiner S, Shahar R. Importance of the integrity of trabecular bone to the relationship between load and deformation of rat femora: an optical metrology study. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b805661g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Shahar R, Zaslansky P, Barak M, Friesem AA, Currey JD, Weiner S. Anisotropic Poisson's ratio and compression modulus of cortical bone determined by speckle interferometry. J Biomech 2007; 40:252-64. [PMID: 16563402 DOI: 10.1016/j.jbiomech.2006.01.021] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Accepted: 01/16/2006] [Indexed: 10/24/2022]
Abstract
Young's modulus and Poisson's ratios of 6mm-sized cubes of equine cortical bone were measured in compression using a micro-mechanical loading device. Surface displacements were determined by electronic speckle pattern-correlation interferometry. This method allows for non-destructive testing of very small samples in water. Analyses of standard materials showed that the method is accurate and precise for determining both Young's modulus and Poisson's ratio. Material properties were determined concurrently in three orthogonal anatomic directions (axial, radial and transverse). Young's modulus values were found to be anisotropic and consistent with values of equine cortical bone reported in the literature. Poisson's ratios were also found to be anisotropic, but lower than those previously reported. Poisson's ratios for the radial-transverse and transverse-radial directions were 0.15+/-0.02, for the axial-transverse and axial-radial directions 0.19+/-0.04, and for the transverse-axial and radial-axial direction 0.09+/-0.02 (mean+/-SD). Cubes located only millimetres apart had significantly different elastic properties, showing that significant spatial variation occurs in equine cortical bone.
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Affiliation(s)
- R Shahar
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, P.O. Box 12, 76100 Rehorot, Israel.
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Zaslansky P, Friesem AA, Weiner S. Structure and mechanical properties of the soft zone separating bulk dentin and enamel in crowns of human teeth: insight into tooth function. J Struct Biol 2005; 153:188-99. [PMID: 16414277 DOI: 10.1016/j.jsb.2005.10.010] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2005] [Revised: 10/10/2005] [Accepted: 10/12/2005] [Indexed: 11/21/2022]
Abstract
The 200-300 microm soft zone of dentin, found beneath enamel in crowns of human teeth, is thought to fulfill important roles in tooth function, but little is known about its structure-mechanical relations. Scanning electron microscopy images of fracture surfaces showed that near the dentino-enamel junction (DEJ), a porous reticulate matrix of intertubular-dentin contains tubules with no peritubular lining. Peritubular-dentin however is found at some distance from the DEJ, and it gradually thickens with increasing depth into the bulk dentin. Concurrently, tighter packing of the collagen fibers is observed with a gradual increase in mineral deposits on and between the fibers. This structurally graded zone is known to be softer when tested for micro-hardness. It undergoes greater strain compared to bulk dentin, when measured using Moiré interferometry. We investigated the deformation and stiffness of this zone by means of non-contact laser-speckle interferometry (ESPI), and nanometer-scale deformations were tracked during compression-testing performed in water. We report a significantly reduced stiffness of this zone compared to bulk dentin, with mid-buccal regions of teeth averaging 3.5 GPa compared with 9.7 GPa in mid-lingual regions. Our results support and expand upon the hypothesis that the durability of the whole tooth relies upon a bucco-lingual asymmetric matching of stiffness by means of an interphase: a cushioning soft layer between enamel and bulk dentin.
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Affiliation(s)
- Paul Zaslansky
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
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