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Weiner S, Shahar R. Vertebrate mineralized tissues: A modular structural analysis. Acta Biomater 2024; 179:1-12. [PMID: 38561073 DOI: 10.1016/j.actbio.2024.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/04/2024]
Abstract
Vertebrate mineralized tissues, present in bones, teeth and scales, have complex 3D hierarchical structures. As more of these tissues are characterized in 3D using mainly FIB SEM at a resolution that reveals the mineralized collagen fibrils and their organization into collagen fibril bundles, highly complex and diverse structures are being revealed. In this perspective we propose an approach to analyzing these tissues based on the presence of modular structures: material textures, pore shapes and sizes, as well as extents of mineralization. This modular approach is complimentary to the widely used hierarchical approach for describing these mineralized tissues. We present a series of case studies that show how some of the same structural modules can be found in different mineralized tissues, including in bone, dentin and scales. The organizations in 3D of the various structural modules in different tissues may differ. This approach facilitates the framing of basic questions such as: are the spatial relations between modular structures the same or similar in different mineralized tissues? Do tissues with similar sets of modules carry out similar functions or can similar functions be carried out using a different set of modular structures? Do mineralized tissues with similar sets of modules have a common developmental or evolutionary pathway? STATEMENT OF SIGNIFICANCE: 3D organization studies of diverse vertebrate mineralized tissues are revealing detailed, but often confusing details about the material textures, the arrangements of pores and differences in the extent of mineralization within a tissue. The widely used hierarchical scheme for describing such organizations does not adequately provide a basis for comparing these tissues, or addressing issues such as structural components thought to be characteristic of bone, being present in dermal tissues and so on. The classification scheme we present is based on identifying structural components within a tissue that can then be systematically compared to other vertebrate mineralized tissues. We anticipate that this classification approach will provide insights into structure-function relations, as well as the evolution of these tissues.
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Affiliation(s)
- Steve Weiner
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Ron Shahar
- Faculty of Agriculture Food & Environment, Koret School of Veterinary Medicine, Hebrew University Jerusalem, P.O.B. 12, Rehovot 7610001, Israel
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Thangadurai S, Majkut M, Milgram J, Zaslansky P, Shahar R, Raguin E. Focused ion beam-SEM 3D study of osteodentin in the teeth of the Atlantic wolfish Anarhichas lupus. J Struct Biol 2024; 216:108062. [PMID: 38224900 DOI: 10.1016/j.jsb.2024.108062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/25/2023] [Accepted: 01/10/2024] [Indexed: 01/17/2024]
Abstract
The palette of mineralized tissues in fish is wide, and this is particularly apparent in fish dentin. While the teeth of all vertebrates except fish contain a single dentinal tissue type, called orthodentin, dentin in the teeth of fish can be one of several different tissue types. The most common dentin type in fish is orthodentin. Orthodentin is characterized by several key structural features that are fundamentally different from those of bone and from those of osteodentin. Osteodentin, the second-most common dentin type in fish (based on the tiny fraction of fish species out of ∼30,000 extant fish species in which tooth structure was so far studied), is found in most Selachians (sharks and rays) as well as in several teleost species, and is structurally different from orthodentin. Here we examine the hypothesis that osteodentin is similar to anosteocytic bone tissue in terms of its micro- and nano-structure. We use Focused Ion Beam-Scanning Electron Microscopy (FIB/SEM), as well as several other high-resolution imaging techniques, to characterize the 3D architecture of the three main components of osteodentin (denteons, inter-denteonal matrix, and the transition zone between them). We show that the matrix of osteodentin, although acellular, is extremely similar to mammalian osteonal bone matrix, both in general morphology and in the three-dimensional nano-arrangement of its mineralized collagen fibrils. We also document the presence of a complex network of nano-channels, similar to such networks recently described in bone. Finally, we document the presence of strings of hyper-mineralized small 'pearls' which surround the denteonal canals, and characterize their structure.
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Affiliation(s)
- Senthil Thangadurai
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Marta Majkut
- ESRF - The European Synchrotron Radiation Facility, ID 19, Grenoble, France
| | - Joshua Milgram
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Paul Zaslansky
- Department for Restorative and Preventive Dentistry, Charité-Universitaetsmedizin, Berlin, Germany
| | - Ron Shahar
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
| | - Emeline Raguin
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Potsdam, Germany
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Besnard C, Marie A, Sasidharan S, Harper RA, Shelton RM, Landini G, Korsunsky AM. Synchrotron X-ray Studies of the Structural and Functional Hierarchies in Mineralised Human Dental Enamel: A State-of-the-Art Review. Dent J (Basel) 2023; 11:98. [PMID: 37185477 PMCID: PMC10137518 DOI: 10.3390/dj11040098] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/19/2023] [Accepted: 03/28/2023] [Indexed: 05/17/2023] Open
Abstract
Hard dental tissues possess a complex hierarchical structure that is particularly evident in enamel, the most mineralised substance in the human body. Its complex and interlinked organisation at the Ångstrom (crystal lattice), nano-, micro-, and macro-scales is the result of evolutionary optimisation for mechanical and functional performance: hardness and stiffness, fracture toughness, thermal, and chemical resistance. Understanding the physical-chemical-structural relationships at each scale requires the application of appropriately sensitive and resolving probes. Synchrotron X-ray techniques offer the possibility to progress significantly beyond the capabilities of conventional laboratory instruments, i.e., X-ray diffractometers, and electron and atomic force microscopes. The last few decades have witnessed the accumulation of results obtained from X-ray scattering (diffraction), spectroscopy (including polarisation analysis), and imaging (including ptychography and tomography). The current article presents a multi-disciplinary review of nearly 40 years of discoveries and advancements, primarily pertaining to the study of enamel and its demineralisation (caries), but also linked to the investigations of other mineralised tissues such as dentine, bone, etc. The modelling approaches informed by these observations are also overviewed. The strategic aim of the present review was to identify and evaluate prospective avenues for analysing dental tissues and developing treatments and prophylaxis for improved dental health.
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Affiliation(s)
- Cyril Besnard
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, Oxfordshire, UK
| | - Ali Marie
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, Oxfordshire, UK
| | - Sisini Sasidharan
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, Oxfordshire, UK
| | - Robert A. Harper
- School of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, West Midlands, UK
| | - Richard M. Shelton
- School of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, West Midlands, UK
| | - Gabriel Landini
- School of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, West Midlands, UK
| | - Alexander M. Korsunsky
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, Oxfordshire, UK
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Toledano M, Osorio E, Osorio MT, Aguilera FS, Toledano R, Romero EF, Osorio R. Dexamethasone-doped nanoparticles improve mineralization, crystallinity and collagen structure of human dentin. J Dent 2023; 130:104447. [PMID: 36754111 DOI: 10.1016/j.jdent.2023.104447] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/01/2023] [Accepted: 02/04/2023] [Indexed: 02/09/2023] Open
Abstract
OBJECTIVES Bioactive materials have been used for functionalization of adhesives to promote dentin remineralization. This study aims to evaluate bonding ability and both mechanical and chemical behavior of demineralized dentin infiltrated with polymeric nanoparticles doped with dexamethasone (Dex-NPs). METHODS Dentin conditioned surfaces were infiltrated with NPs, Dex-NPs or Dex-Zn-NPs. Bonded interfaces were also created and stored for 24 h or 21d, and then submitted to microtensile bond strength testing. Dentin remineralization was analyzed by Nanohardness, Young's modulus and Raman analysis. RESULTS At 21d of storage, dentin treated with undoped-NPs attained the lowest nanohardness and Young's modulus. Dex-NPs and Zn-Dex-NPs increased dentin nanohardness and Young's modulus after 21d Raman analysis showed high remineralization, crystallinity, crosslinking and better structure of collagen when functionalized Dex-NPs were present at the dentin interface. CONCLUSIONS Infiltration of dentin with Dex-NPs promoted functional remineralization as proved by nanomechanical and morpho-chemical evaluation tests. Dexamethasone in dentin facilitated crystallographic maturity, crystallinity and improved maturity and secondary structure of dentin collagen. CLINICAL SIGNIFICANCE Using dexamethasone-functionalized NPs before resin infiltration is a clear option to obtain dentin remineralization, as these NPs produce the reinforcement of the dentin structure, which will lead to the improvement of the longevity of resin restorations.
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Affiliation(s)
- Manuel Toledano
- Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, University of Granada, Granada 18071, Spain
| | - Estrella Osorio
- Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, University of Granada, Granada 18071, Spain
| | - María T Osorio
- Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, University of Granada, Granada 18071, Spain
| | - Fátima S Aguilera
- Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, University of Granada, Granada 18071, Spain.
| | - Raquel Toledano
- Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, University of Granada, Granada 18071, Spain
| | - Enrique Fernández- Romero
- Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, University of Granada, Granada 18071, Spain
| | - Raquel Osorio
- Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, University of Granada, Granada 18071, Spain
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Inchingolo AM, Patano A, Di Pede C, Inchingolo AD, Palmieri G, de Ruvo E, Campanelli M, Buongiorno S, Carpentiere V, Piras F, Settanni V, Viapiano F, Hazballa D, Rapone B, Mancini A, Di Venere D, Inchingolo F, Fatone MC, Palermo A, Minetti E, Lorusso F, Scarano A, Sauro S, Tartaglia GM, Bordea IR, Dipalma G, Malcangi G. Autologous Tooth Graft: Innovative Biomaterial for Bone Regeneration. Tooth Transformer® and the Role of Microbiota in Regenerative Dentistry. A Systematic Review. J Funct Biomater 2023; 14:jfb14030132. [PMID: 36976056 PMCID: PMC10058341 DOI: 10.3390/jfb14030132] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 03/05/2023] Open
Abstract
Different biomaterials, from synthetic products to autologous or heterologous grafts, have been suggested for the preservation and regeneration of bone. The aim of this study is to evaluate the effectiveness of autologous tooth as a grafting material and examine the properties of this material and its interactions with bone metabolism. PubMed, Scopus, Cochrane Library, and Web of Science were searched to find articles addressing our topic published from 1 January 2012 up to 22 November 2022, and a total of 1516 studies were identified. Eighteen papers in all were considered in this review for qualitative analysis. Demineralized dentin can be used as a graft material, since it shows high cell compatibility and promotes rapid bone regeneration by striking an ideal balance between bone resorption and production; it also has several benefits, such as quick recovery times, high-quality newly formed bone, low costs, no risk of disease transmission, the ability to be performed as an outpatient procedure, and no donor-related postoperative complications. Demineralization is a crucial step in the tooth treatment process, which includes cleaning, grinding, and demineralization. Since the presence of hydroxyapatite crystals prevents the release of growth factors, demineralization is essential for effective regenerative surgery. Even though the relationship between the bone system and dysbiosis has not yet been fully explored, this study highlights an association between bone and gut microbes. The creation of additional scientific studies to build upon and enhance the findings of this study should be a future objective of scientific research.
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Affiliation(s)
| | - Assunta Patano
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Chiara Di Pede
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | | | - Giulia Palmieri
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Elisabetta de Ruvo
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Merigrazia Campanelli
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Silvio Buongiorno
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Vincenzo Carpentiere
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Fabio Piras
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Vito Settanni
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Fabio Viapiano
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Denisa Hazballa
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Biagio Rapone
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Antonio Mancini
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Daniela Di Venere
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Francesco Inchingolo
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
- Correspondence: (F.I.); (M.C.F.); Tel.: +39-331-211-1104 (F.I.); +39-3479914635 (M.C.F.)
| | - Maria Celeste Fatone
- PTA Trani-ASL BT, Viale Padre Pio, 76125 Trani, Italy
- Correspondence: (F.I.); (M.C.F.); Tel.: +39-331-211-1104 (F.I.); +39-3479914635 (M.C.F.)
| | - Andrea Palermo
- College of Medicine and Dentistry Birmingham, University of Birmingham, Birmingham B4 6BN, UK
| | - Elio Minetti
- Department of Biomedical, Surgical, and Dental Science, Università Degli Studi di Milano, 20122 Milan, Italy
| | - Felice Lorusso
- Department of Innovative Technologies in Medicine and Dentistry, University of Chieti-Pescara, 66100 Chieti, Italy
| | - Antonio Scarano
- Department of Innovative Technologies in Medicine and Dentistry, University of Chieti-Pescara, 66100 Chieti, Italy
| | - Salvatore Sauro
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
- Dental Biomaterials and Minimally Invasive Dentistry, Department of Dentistry, Cardenal Herrera-CEU University, CEU Universities, C/Santiago Ramón y Cajal, s/n., Alfara del Patriarca, 46115 Valencia, Spain
| | - Gianluca Martino Tartaglia
- Department of Biomedical, Surgical and Dental Sciences, School of Dentistry, University of Milan, 20100 Milan, Italy
- UOC Maxillo-Facial Surgery and Dentistry Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Ioana Roxana Bordea
- Department of Oral Rehabilitation, Faculty of Dentistry, Iuliu Hațieganu University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Gianna Dipalma
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Giuseppina Malcangi
- Department of Interdisciplinary Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy
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Dexamethasone and zinc loaded polymeric nanoparticles reinforce and remineralize coronal dentin. A morpho-histological and dynamic-biomechanical study. Dent Mater 2023; 39:41-56. [PMID: 36460577 DOI: 10.1016/j.dental.2022.11.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/18/2022] [Accepted: 11/25/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the effect of novel polymeric nanoparticles (NPs) doped with dexamethasone (Dex) on viscoelasticity, crystallinity and ultra-nanostructure of the formed hydroxyapatite after NPs dentin infiltration. METHODS Undoped-NPs, Dex-doped NPs (Dex-NPs) and zinc-doped-Dex-NPs (Zn-Dex-NPs) were tested at dentin, after 24 h and 21 d. A control group without NPs was included. Coronal dentin surfaces were studied by nano-dynamic mechanical analysis measurements, atomic force microscopy, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). RESULTS At 21 d of storage time, both groups doped with Dex exhibited the highest complex, storage and loss moduli among groups. Zn-Dex-NPs and Dex-NPs promoted the highest and lowest tan delta values, respectively. Dex-NPs contributed to increase the fibril diameters of dentin collagen over time. Dentin surfaces treated with Zn-Dex-NPs attained the lowest nano-roughness values, provoked the highest crystallinity, and produced the longest and shortest crystallite and grain size. These new crystals organized with randomly oriented lattices. Dex-NPs induced the highest microstrain. Crystalline and amorphous matter was present in the mineral precipitates of all groups, but Zn and Dex loaded NPs helped to increase crystallinity. SIGNIFICANCE Dentin treated with Zn-Dex-NPs improved crystallographic and atomic order, providing structural stability, high mechanical performance and tissue maturation. Amorphous content was also present, so high hydroxyapatite solubility, bioactivity and remineralizing activity due to the high ion-rich environment took place in the infiltrated dentin.
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Franca CM, Balbinot GDS, Cunha D, Saboia VDPA, Ferracane J, Bertassoni LE. In-vitro models of biocompatibility testing for restorative dental materials: From 2D cultures to organs on-a-chip. Acta Biomater 2022; 150:58-66. [PMID: 35933103 PMCID: PMC9814917 DOI: 10.1016/j.actbio.2022.07.060] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 07/13/2022] [Accepted: 07/28/2022] [Indexed: 02/08/2023]
Abstract
Dental caries is a biofilm-mediated, diet-modulated, multifactorial and dynamic disease that affects more than 90% of adults in Western countries. The current treatment for decayed tissue is based on using materials to replace the lost enamel or dentin. More than 500 million dental restorations are placed annually worldwide, and materials used for these purposes either directly or indirectly interact with dentin and pulp tissues. The development and understanding of the effects of restorative dental materials are based on different in-vitro and in-vivo tests, which have been evolving with time. In this review, we first discuss the characteristics of the tooth and the dentin-pulp interface that are unique for materials testing. Subsequently, we discuss frequently used in-vitro tests to evaluate the biocompatibility of dental materials commonly used for restorative procedures. Finally, we present our perspective on the future directions for biological research on dental materials using tissue engineering and organs on-a-chip approaches. STATEMENT OF SIGNIFICANCE: Dental caries is still the most prevalent infectious disease globally, requiring more than 500 million restorations to be placed every year. Regrettably, the failure rates of such restorations are still high. Those rates are partially based on the fact that current platforms to test dental materials are somewhat inaccurate in reproducing critical components of the complex oral microenvironment. Thus, there is a collective effort to develop new materials while evolving the platforms to test them. In this context, the present review critically discusses in-vitro models used to evaluate the biocompatibility of restorative dental materials and brings a perspective on future directions for tissue-engineered and organs-on-a-chip platforms for testing new dental materials.
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Affiliation(s)
- Cristiane Miranda Franca
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, United States
| | - Gabriela de Souza Balbinot
- Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Diana Cunha
- Post-Graduation Program in Dentistry, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | - Jack Ferracane
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, United States
| | - Luiz E Bertassoni
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, United States; Center for Regenerative Medicine, School of Medicine, Oregon Health & Science University, Portland, OR, United States; Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, OR, United States; Cancer Early Detection Advanced Research Center (CEDAR), Knight Cancer Institute, Portland, OR, United States.
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Xu H, Ye Z, Zhang A, Lin F, Fu J, Fok ASL. Effects of concentration of sodium hypochlorite as an endodontic irrigant on the mechanical and structural properties of root dentine: A laboratory study. Int Endod J 2022; 55:1091-1102. [PMID: 35833329 PMCID: PMC9545283 DOI: 10.1111/iej.13800] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 07/03/2022] [Accepted: 07/04/2022] [Indexed: 11/30/2022]
Abstract
AIM The use of high-concentration sodium hypochlorite (NaOCl) as an endodontic irrigant remains controversial because of its potential impact on the fracture strength of endodontically-treated teeth. This study evaluated the effects of using different NaOCl concentrations, with 2-min-ethylenediaminetetraacetic acid (EDTA) as the final active irrigant, on the biomechanical and structural properties of root dentine. METHODOLOGY A new test method, which is more clinically relevant, was utilized to calculate the fracture strength of root dentine. Bovine incisors were used to obtain root dentine discs. The root canals were enlarged to mean diameter of 2.90 mm with a taper of 0.06. The resulting discs were divided into 5 groups (n=20) and treated with different concentrations of NaOCl (5.25%, 2.5%, and 1.3%) for 30 min plus 17% EDTA for 2 min. The discs were then loaded to fracture by a steel rod with the same taper through the central hole. The fractured specimens were examined by scanning electron microscopy to evaluate changes in the dimensions of the remaining intertubular dentine and the tubular radius. Micro-hardness was also measured with a Knoop diamond indenter along a radius to determine the depth of dentine eroded by the irrigation. Results were analyzed by one-way ANOVA and the Tukey test. The level of significance was set at α = 0.05. RESULTS The damage by NaOCl increased with its concentration. 5.25% NaOCl greatly reduced the fracture strength of root dentine from 172.10±30.13 MPa to 114.58±26.74 MPa. The corresponding reduction in micro-hardness at the root canal wall was 34.1%. The damages reached a depth of up to 400 μm (p < 0.05). Structural changes involved degradation of the intratubular wall leading to enlarged dentinal tubules and the loss of intertubular dentine. Changes in the microstructural parameters showed positive linear relationships with the fracture strength. CONCLUSIONS With the adjunctive use of EDTA, NaOCl caused destruction to the intratubular surface near the root canal and, consequently, reduced the root dentine's mechanical strength. The higher the concentration of NaOCl, the greater the effect. Therefore, endodontists should avoid using overly high concentration of NaOCl for irrigation to prevent potential root fracture in endodontically-treated teeth.
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Affiliation(s)
- Haiping Xu
- Department of Stomatology, the Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, MN, United States
| | - Zhou Ye
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, MN, United States.,Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong S.A.R, China
| | - Anqi Zhang
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, MN, United States
| | - Fei Lin
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Jing Fu
- Department of Stomatology, the Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Alex S L Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, MN, United States
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Moraes GF, Caetano RDO, Prochnow FHO, Pupo YM, Schussel JL, Schwartz-Filho HO. Demineralized human dentin matrix for alveolar ridge preservation using a volumetric and histologic analyses in rats. Braz Dent J 2022; 33:82-91. [PMID: 35766721 PMCID: PMC9645199 DOI: 10.1590/0103-6440202204648] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 03/02/2022] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to evaluate a Demineralized Human Dentine Matrix (DHDM)
as viable biomaterial for alveolar ridge preservation in a rat model. Wistar
rats were submitted to the extraction of maxillary first molars bilaterally.
Sockets were filled with biomaterials and divided into 4 experimental groups
(n=5): blood clot, autogenous bone, bovine-derived xenograft (BDX) and DHDM.
Animals were sacrificed at 7, 14 e 28 days. Microtomography (uCT) volumetric
evaluation and qualitative histological analyses were performed. Results
obtained through the uCT showed similar values between the DHDM and the other
experimental groups. The histological evaluation demonstrated DHDM with an
unspecific inflammatory process and bone neoformation with slow reabsorption of
the material. This result indicates that DHDM implanted in rat sockets is
biocompatible and reduces the alveolar ridge volume loss after tooth
extraction.
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Affiliation(s)
- Gabriela Fracasso Moraes
- Post graduate Program in Dentistry, Department of Stomatology, Universidade Federal do Paraná, UFPR, Curitiba, Brazil
| | - Rodrigo de Oliveira Caetano
- Post graduate Program in Dentistry, Department of Stomatology, Universidade Federal do Paraná, UFPR, Curitiba, Brazil
| | - Fernanda Harumi Oku Prochnow
- Post graduate Program in Dentistry, Department of Stomatology, Universidade Federal do Paraná, UFPR, Curitiba, Brazil
| | - Yasmine Mendes Pupo
- Post graduate Program in Dentistry, Department of Restorative Dentistry, Universidade Federal do Paraná, UFPR, Curitiba, Brazil
| | - Juliana Lucena Schussel
- Post graduate Program in Dentistry, Department of Stomatology, Universidade Federal do Paraná, UFPR, Curitiba, Brazil
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Toledano-Osorio M, Aguilera FS, Muñoz-Soto E, Osorio E, Toledano M, Escames G, Medina-Castillo AL, Osorio MT, López-López MT, Vallecillo-Rivas M, Osorio R. Melatonin-doped polymeric nanoparticles induce high crystalline apatite formation in root dentin. Dent Mater 2021; 37:1698-1713. [PMID: 34544591 DOI: 10.1016/j.dental.2021.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/04/2021] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the effect of novel polymeric nanoparticles (NPs) doped with melatonin (ML) on nano-hardness, crystallinity and ultrastructure of the formed hydroxyapatite after endodontic treatment. METHODS Undoped-NPs and ML-doped NPs (ML-NPs) were tested at radicular dentin, after 24 h and 6 m. A control group without NPs was included. Radicular cervical and apical dentin surfaces were studied by nano-hardness measurements, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). RESULTS Cervical dentin treated with undoped NPs maintained its nano-hardness values after 6 m of storage being [24 h: 0.29 (0.01); 6 m: 0.30 (0.02) GPa], but it decreased at apical dentin [24 h: 0.36 (0.01); 6 m: 0.28 (0.02) GPa]. When ML-NPs were used, nano-hardness was similar over time [24h: 0.31 (0.02); 6 m: 0.28 (0.03) GPa], at apical dentin. Root dentin treated with ML-NPs produced, in general, high crystallinity of new minerals and thicker crystals than those produced in the rest of the groups. After 6 m, crystals became organized in randomly oriented polyhedral, square polygonal block-like apatite or drop-like apatite polycrystalline lattices when ML-NPs were used. Undoped NPs generated poor crystallinity, with preferred orientation of small crystallite and increased microstrain. SIGNIFICANCE New polycrystalline formations encountered in dentin treated with ML-NPs may produce structural dentin stability and high mechanical performance at the root. The decrease of mechanical properties over time in dentin treated without NPs indicates scarce remineralization potential, dentin demineralization and further potential degradation. The amorphous stage may provide high hydroxyapatite solubility and remineralizing activity.
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Affiliation(s)
- Manuel Toledano-Osorio
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Fátima S Aguilera
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Esther Muñoz-Soto
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Estrella Osorio
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Manuel Toledano
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain.
| | - Germaine Escames
- Faculty of Medicine, Department of Physiology, Biomedical Research Center, CIBERFES, Ibs. San Cecilio University Hospital, University of Granada, Granada, Spain
| | - Antonio L Medina-Castillo
- University of Granada, NanoMyP, Spin-Off Enterprise, Edificio BIC-Granada, Av. Innovación 1, 18016, Armilla, Granada, Spain
| | | | - Modesto T López-López
- University of Granada, Faculty of Science, Applied Physics Department, Av. Fuente Nueva s/n, 18071 Granada, Spain
| | - Marta Vallecillo-Rivas
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
| | - Raquel Osorio
- University of Granada, Department of Stomatology, Colegio Máximo de Cartuja s/n, Granada 18071, Spain
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11
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Bakhsh TA, Abuljadayel JA, Alshouibi E, Abuljadayel RA. Advanced imaging of dentin microstructure. Biomed Phys Eng Express 2021; 7. [PMID: 34340215 DOI: 10.1088/2057-1976/ac19cf] [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: 05/14/2021] [Accepted: 08/02/2021] [Indexed: 11/11/2022]
Abstract
This study aimed to demonstrate the feasibility of using optical coherence tomography (OCT) for locating the sectioning site of a specimen before characterizing the ultrastructural features of dentin surfaces as well as the inner wall of the dentinal tubules (DT) using a field emission scanning electron microscope (FESEM). Eight sound human molar teeth were extracted, examined via cross-polarization optical coherence tomography (CP-OCT), embedded, and hemisectioned using a low-speed diamond sawing machine. Next, each sectioned surface was further trimmed, polished, and examined under a confocal laser scanning microscope (CLSM) to locate the target area on the superficial dentin. Subsequently, each section was gold-coated and examined using FESEM. Backscattered reflection from the dentin layer was less than that from the enamel under CP-OCT. Distinct reflections from certain enamel and dentin microstructures were observed before sectioning the specimens. Areas with enamel cracks and dentin defects were identified and avoided during sectioning. At the micron level, the CLSM images exhibited a homogenous distribution of the DT orifices. Low magnification FESEM images showed intertubular dentin as a loosely condensed globular layer with shallow grooves in between, whereas peritubular dentin exhibited more organized condensation of apatite crystals surrounding the DT orifices. High magnification of the DT revealed a cross-linking layer of mineralized collagen network extending in the peri-intratubular lumen, with scattered globules of matrix vesicles. CP-OCT enabled the realization of rapid initial scanning and image acquisition with high contrast at the micron scale before profound insights into dentin ultrastructures at the nano scale were provided by FESEM. The variations in structural densities of the dental tissues significantly affected the image contrast and helped identify underlying structures.
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Affiliation(s)
- T A Bakhsh
- Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, PO Box 80209, Jeddah 215-89, Saudi Arabia
| | - J A Abuljadayel
- Preventive Dentistry Department, Faculty of Dentistry, Umm Al-Qura University, Makkah, Saudi Arabia
| | - E Alshouibi
- Dental Public Health Department, Faculty of Dentistry, King Abdulaziz University, PO Box 80209, Jeddah 215-89, Saudi Arabia
| | - R A Abuljadayel
- Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, PO Box 80209, Jeddah 215-89, Saudi Arabia
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12
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Melatonin-doped polymeric nanoparticles reinforce and remineralize radicular dentin: Morpho-histological, chemical and biomechanical studies. Dent Mater 2021; 37:1107-1120. [PMID: 33846017 DOI: 10.1016/j.dental.2021.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/15/2021] [Accepted: 03/28/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVES To investigate the effectiveness of novel polymeric nanoparticles (NPs) doped with melatonin (ML) in reducing dentin permeability and facilitating dentin remineralization after endodontic treatment. METHODS The effect of undoped NPs and ML-doped NPs (ML-NPs) was tested in radicular dentin, at 24 h and 6 m. A control group without NPs was included. ML liberation was measured. Radicular dentin was assessed for fluid filtration. Dentin remineralization was analyzed by scanning electron microscopy, AFM, Young's modulus (Ei), Nano DMA-tan delta, and Raman analysis. RESULTS ML release ranged from 1.85 mg/mL at 24 h to 0.033 mg/mL at 28 d. Both undoped NPs and ML-NPs treated dentin exhibited the lowest microleakage, but samples treated with ML-NPs exhibited hermetically sealed dentinal tubules and extended mineral deposits onto dentin. ML-NPs promoted higher and durable Ei, and functional remineralization at root dentin, generating differences between the values of tan delta among groups and creating zones of stress concentration. Undoped-NPs produced closure of some tubules and porosities at the expense of a relative mineral amorphization. Chemical remineralization based on mineral and organic assessments was higher in samples treated with ML-NPs. When using undoped NPs, precipitation of minerals occurred; however, radicular dentin was not mechanically reinforced but weakened over time. SIGNIFICANCE Application of ML-NPs in endodontically treated teeth, previous to the canal filling step, is encouraged due to occlusion of dentinal tubules and the reinforcement of the radicular dentin structure.
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Zn-doping of silicate and hydroxyapatite-based cements: Dentin mechanobiology and bioactivity. J Mech Behav Biomed Mater 2020; 114:104232. [PMID: 33290910 DOI: 10.1016/j.jmbbm.2020.104232] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/17/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022]
Abstract
The objective was to state zinc contribution in the effectiveness of novel zinc-doped dentin cements to achieve dentin remineralization, throughout a literature or narrative exploratory review. Literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. Both zinc-doping silicate and hydroxyapatite-based cements provoked an increase of both bioactivity and intrafibrillar mineralization of dentin. Zinc-doped hydroxyapatite-based cements (oxipatite) also induced an increase in values of dentin nano-hardness, Young's modulus and dentin resistance to deformation. From Raman analyses, it was stated higher intensity of phosphate peaks and crystallinity as markers of dentin calcification, in the presence of zinc. Zinc-based salt formations produced low microleakage and permeability values with hermetically sealed tubules at radicular dentin. Dentin treated with oxipatite attained preferred crystal grain orientation with polycrystalline lattices. Thereby, oxipatite mechanically reinforced dentin structure, by remineralization. Dentin treated with oxipatite produced immature crystallites formations, accounting for high hydroxyapatite solubility, instability and enhanced remineralizing activity.
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14
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Maghami E, Pejman R, Najafi AR. Fracture micromechanics of human dentin: A microscale numerical model. J Mech Behav Biomed Mater 2020; 114:104171. [PMID: 33218927 DOI: 10.1016/j.jmbbm.2020.104171] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/17/2020] [Accepted: 10/23/2020] [Indexed: 11/25/2022]
Abstract
In the present study, we investigate the effects of microstructural morphology and heterogeneity on the initiation and propagation of microcracks in dentin. We create 2D pre-cracked models of human dentin at the microscale level and use a brittle fracture framework of the phase-field method to analyze the crack growth. We discuss the influence of the microstructural features on crack deflection, microcracking, and uncracked ligament bridging through various regions in dentin. The results demonstrate that the difference between the critical energy release rates of peritubular (PTD) and intertubular dentin (ITD) has considerable impacts on microcracking. Our simulations reveal that tubules surrounded by PTDs play an important role in the crack deflection. Our results also indicate that the toughness of dentin increases from the inner to outer dentin. In conclusion, the findings in our study provide valuable insights into the fracture behavior in various regions of dentin.
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Affiliation(s)
- Ebrahim Maghami
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA
| | - Reza Pejman
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA
| | - Ahmad R Najafi
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA.
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15
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Bafail A, Carrilho MR, Kishen A, Prakki A. Effect of protease inhibitor specificity on dentin matrix properties. J Mech Behav Biomed Mater 2020; 109:103861. [PMID: 32543386 DOI: 10.1016/j.jmbbm.2020.103861] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate protease activity of dentin matrices subjected to treatment with non-specific (chlorhexidine - CHX), cysteine cathepsin specific (E-64), and cysteine cathepsin-K (CT-K) specific (Odanacatib - ODN) inhibitors. METHODS Pulverized dentin powder obtained from human dentin disks (0.5 mm thickness) completely demineralized with 10% H3PO4 were challenged in 1 mL lactic acid (LA) (0.1M, pH 5.5) or stored in deionized water for 30 min. Aliquots of dentin powder were then immersed in 1 mL of CHX (2%), E-64 (10 μM and 20 μM) or Odanacatib (0.2 nM and 1 μM) for 30min. Degradation of dentin collagen was determined by telopeptide assays measuring the sub-product release of C-terminal cross-linked telopeptides (ICTP) and C-terminal peptide (CTX) in incubation media, which correlates with matrix metalloproteinases (MMP) and CT-K activities respectively (n = 3). The ICTP and CTX data were normalized to concentration of total protein (ICTPtp and CTXtp) in the media, measured by bicinchoninic acid assay. Dentin matrix properties were also measured by gravimetric change (n = 8) and ultimate tensile strength (UTS) (n = 10). Data were analyzed by one-way ANOVA followed by Tukey's post-hoc test and independent t-test (α = 5%). RESULTS Telopeptide assays showed significantly lower CTXtp values after treatment with E-64 and Odanacatib. E-64 and Odanacatib at all tested concentrations significantly reduced the release of ICTPtp. Gravimetric analysis showed no significant difference between the tested inhibitors and control except for CHX after lactic acid challenge. UTS results showed significantly higher values for E-64 (20 μM) and Odanacatib (0.2 nM and 1 μM) groups in deionized water. SIGNIFICANCE Dentin therapies targeting enzymes such as CT-K by specific inhibitors may provide superior pharmacokinetics and optimum efficacy due to precise protein binding, consequently limiting collagen degradation directly or indirectly by enzyme related pathways.
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Affiliation(s)
- Arwa Bafail
- Dental Research Institute, Faculty of Dentistry, University of Toronto, 124 Edward St, Toronto, ON, M5G 1G6, Canada; Restorative Dental Sciences, Faculty of Dentistry, Taibah University, Janadah Bin Umayyah Road, Tayba, Medina, 42353, Saudi Arabia
| | - Marcela Rocha Carrilho
- College of Dental Medicine Illinois, Midwestern University, 555 31st Street, Downers Grove, IL, 60515, USA
| | - Anil Kishen
- Dental Research Institute, Faculty of Dentistry, University of Toronto, 124 Edward St, Toronto, ON, M5G 1G6, Canada
| | - Anuradha Prakki
- Dental Research Institute, Faculty of Dentistry, University of Toronto, 124 Edward St, Toronto, ON, M5G 1G6, Canada.
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16
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Ivica A, Deari S, Patcas R, Weber FE, Zehnder M. Transforming Growth Factor Beta 1 Distribution and Content in the Root Dentin of Young Mature and Immature Human Premolars. J Endod 2020; 46:641-647. [PMID: 32139264 DOI: 10.1016/j.joen.2020.01.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/10/2020] [Accepted: 01/21/2020] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Transforming growth factor beta 1 (TGF-β1) is a key morphogen in regenerative endodontics; yet, its location within the hard tissue phase of dentin and its availability in mature roots have not been fully elucidated. METHODS Young mature (n = 8) and immature (n = 11) roots from sound premolars were obtained from 13 orthodontic patients aged 17 ± 1 and 12 ± 1 years, respectively. Roots were cleaned of organic remnants in 5% sodium hypochlorite. The width of the minor foramen was measured using a digital microscope. TGF-β1 distribution was assessed in 3 roots per group by immunostaining combined with confocal laser scanning microscopy. The root dentin of the remaining 13 roots was powdered and decalcified in 17% EDTA to determine the overall levels of hard tissue-embedded TGF-β1 by enzyme-linked immunosorbent assay. Data were compared between groups using the Student t test (α = .05). RESULTS The minor foramen was 168 ± 49 μm versus 557 ± 295 μm in mature compared with immature roots (P < .05). TGF-β1 was highly stainable toward the pulp space in both groups. It was clearly associated with peritubular dentin and apparently absent in nontubular outer dentin. TGF-β1 content was 115 ± 31 pg and 74 ± 35 pg/100 mg mature versus immature root dentin, respectively (P > .05). CONCLUSIONS TGF-β1 is deposited into the peritubular dentin. It should be possible to release this molecule in regenerative endodontic procedures from young mature roots as well as immature roots.
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Affiliation(s)
- Anja Ivica
- Department of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Department of Oral Biotechnology and Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Shengjile Deari
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Raphael Patcas
- Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Franz E Weber
- Department of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Department of Oral Biotechnology and Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Matthias Zehnder
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
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17
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Alania Y, Creighton J, Trevelin LT, Zamperini CA, Bedran-Russo AK. Regional contribution of proteoglycans to the fracture toughness of the dentin extracellular matrix. J Biomech 2020; 101:109633. [PMID: 32035660 DOI: 10.1016/j.jbiomech.2020.109633] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 01/06/2020] [Accepted: 01/12/2020] [Indexed: 12/11/2022]
Abstract
This study investigated the contribution of small leucine rich proteoglycans (SLRPs) to the fracture toughness of the dentin extracellular matrix (ECM) by enzymatically-assisted selective removal of glycosaminoglycan chains (GAGs) and proteoglycans (PGs) core protein. We adapted the Mode III trouser tear test to evaluate the energy required to tear the dentin ECM. Trouser-shaped dentin specimens from crown and root were demineralized. Depletion of GAGs and PGs followed enzymatic digestion using chondroitinase ABC (c-ABC) and matrix metalloproteinase 3 (MMP-3), respectively. The legs from specimen were stretched under tensile force and the load at tear propagation was determined to calculate the tear energy (T, kJ/m2). SLRPs decorin and biglycan were visualized by immunohistochemistry and ECM tear pattern was analyzed in SEM. Results showed T of crown ECM was not affected by PGs/GAGs depletion (p = 0.799), whereas the removal of PGs significantly reduced T in root dentin ECM (p = 0.001). Root dentin ECM exhibited higher T than crown (p < 0.03), however no regional difference are present after PG depletion (p = 0.480). Immunohistochemistry confirmed removal of GAGs and PGs. SEM images showed structural modifications after PGs/GAGs removal such as enlargement of dentinal tubules, increased interfibrillar spaces and presence of untwisted fibrils with increased diameter. Findings indicate that the capacity of the PGs to unfold and untwist contribute to the dentin ECM resistance to tear, possibly influencing crack growth propagation. The regional differences are likely an evolutionary design to increase tooth survival, that undergoes repetitive mechanical loading and load stress dissipation over a lifetime of an individual.
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Affiliation(s)
- Yvette Alania
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina St, Chicago, IL 60612, USA
| | - Johnathon Creighton
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina St, Chicago, IL 60612, USA
| | - Livia T Trevelin
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina St, Chicago, IL 60612, USA; Department of Restorative Dentistry, School of Dentistry, Municipal University of São Caetano do Sul, Rua Santo Antônio 50, São Caetano do Sul, São Paulo 09521-160, Brazil
| | - Camila A Zamperini
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina St, Chicago, IL 60612, USA
| | - Ana K Bedran-Russo
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina St, Chicago, IL 60612, USA.
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18
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Hu J, Sui T. Insights into the reinforcement role of peritubular dentine subjected to acid dissolution. J Mech Behav Biomed Mater 2020; 103:103614. [PMID: 32090938 DOI: 10.1016/j.jmbbm.2019.103614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 12/29/2019] [Accepted: 12/31/2019] [Indexed: 10/25/2022]
Abstract
Human dentine is a mineralised dental tissue that consists of dentinal tubules surrounded by two distinct dentinal phases: peritubular dentine (PTD) and intertubular dentine (ITD). Dental caries, which manifests itself as a consequence of demineralisation, is one of the most common chronic diseases that affect the function of human teeth. Due to the difference in the packing density of crystallites, PTD and ITD exhibit different reaction rates to acid dissolution. The present study evaluates how the effective Young's modulus degrades and how the effective stress redistributes in demineralised human dentine as a result of incremental acid dissolution process. An analytical two-layer composite model is proposed and used for the effective Young's modulus calculation. 3D numerical representative volume elements (RVEs) with different variations in PTD fraction and dentinal tubule density are established to evaluate effective stress redistribution and examine the critical factors that can affect the mechanical performance. The models are then applied on an actual dentine bulk sample. The results reveal how PTD serves as a protection to ITD thus highlight the important role that PTD plays for the structural integrity of dentine. The obtained insights are crucial for advancing the understanding of a variety of natural and therapeutic effects from the mechanical perspective, e.g. the mechanical performance assessment of human dentine subject to complex dynamic processes of de- and re-mineralisation that can occur in human dental caries and dental treatments. It will ultimately inspire the biomimetic design towards strengthening the dentine and dentine-like materials.
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Affiliation(s)
- Jianan Hu
- Sente Software Ltd., 40 Occam Road, Surrey Technology Centre, Guildford, Surrey, GU2 7YG, UK
| | - Tan Sui
- Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK.
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Zappia J, Joiret M, Sanchez C, Lambert C, Geris L, Muller M, Henrotin Y. From Translation to Protein Degradation as Mechanisms for Regulating Biological Functions: A Review on the SLRP Family in Skeletal Tissues. Biomolecules 2020; 10:E80. [PMID: 31947880 PMCID: PMC7023458 DOI: 10.3390/biom10010080] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 12/19/2019] [Accepted: 12/26/2019] [Indexed: 12/27/2022] Open
Abstract
The extracellular matrix can trigger cellular responses through its composition and structure. Major extracellular matrix components are the proteoglycans, which are composed of a core protein associated with glycosaminoglycans, among which the small leucine-rich proteoglycans (SLRPs) are the largest family. This review highlights how the codon usage pattern can be used to modulate cellular response and discusses the biological impact of post-translational events on SLRPs, including the substitution of glycosaminoglycan moieties, glycosylation, and degradation. These modifications are listed, and their impacts on the biological activities and structural properties of SLRPs are described. We narrowed the topic to skeletal tissues undergoing dynamic remodeling.
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Affiliation(s)
- Jérémie Zappia
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
| | - Marc Joiret
- Biomechanics Research Unit, B34 GIGA-R, In Silico Medicine, Liège University, CHU Sart-Tilman, 4000 Liège, Belgium; (M.J.); (L.G.)
| | - Christelle Sanchez
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
| | - Cécile Lambert
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
| | - Liesbet Geris
- Biomechanics Research Unit, B34 GIGA-R, In Silico Medicine, Liège University, CHU Sart-Tilman, 4000 Liège, Belgium; (M.J.); (L.G.)
| | - Marc Muller
- Laboratory for Organogenesis and Regeneration (LOR), GIGA-Research, Liège University, Avenue de l’Hôpital, B-4000 Liège, Belgium;
| | - Yves Henrotin
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
- Physical therapy and Rehabilitation department, Princess Paola Hospital, Vivalia, B-6900 Marche-en-Famenne, Belgium
- Artialis SA, GIGA Tower, Level 3, CHU Sart-Tilman, 4000 Liège, Belgium
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Toledano M, Osorio E, Aguilera FS, Muñoz-Soto E, Toledano-Osorio M, López-López MT, Medina-Castillo AL, Carrasco-Carmona Á, Osorio R. Polymeric nanoparticles for endodontic therapy. J Mech Behav Biomed Mater 2019; 103:103606. [PMID: 32090933 DOI: 10.1016/j.jmbbm.2019.103606] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/19/2019] [Accepted: 12/23/2019] [Indexed: 11/16/2022]
Abstract
The effectiveness of novel polymeric nanoparticles (NPs) application in reducing dentin permeability and facilitating dentin remineralization after endodontic treatment was evaluated. The effect of undoped NPs, zinc, calcium and doxycycline-doped NPs (Zn-NPs, Ca-NPs and D-NPs, respectively) was tested in radicular dentin. A control group without NPs was included. Radicular dentin was assessed for fluid filtration. Dentin remineralization was analyzed by scanning and transmission electron microscopy, energy-dispersive analysis, AFM, Young's modulus (Ei), Nano DMA, Raman, and X-Ray Diffraction analysis. Ca-NPs and Zn-NPs treated dentin exhibited the lowest microleakage with hermetically sealed dentinal tubules and a zinc-based salt generation onto dentin. Zn-NPs favored crystallinity and promoted the highest Ei and functional remineralization at the apical dentin, generating differences between the values of complex modulus among groups. Ca-NPs produced closure of tubules and porosities at the expense of a relative mineral amorphization, without creating zones of stress concentration. The highest sealing efficacy was obtained in Zn-NPs-treated samples, along with the highest values of Young's modulus and dentin mineralization. These high values of Ei were obtained by closing voids, cracks, pores and tubules, and by strengthening the root dentin. When using undoped NPs or Ca-NPs, deposition of minerals occurred, but radicular dentin was not mechanically reinforced. Therefore, application of Zn-NPs in endodontically treated teeth previous to the canal filling is encouraged.
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Affiliation(s)
- Manuel Toledano
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja S/n, Granada, 18071, Spain
| | - Estrella Osorio
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja S/n, Granada, 18071, Spain
| | - Fátima S Aguilera
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja S/n, Granada, 18071, Spain
| | - Esther Muñoz-Soto
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja S/n, Granada, 18071, Spain
| | - Manuel Toledano-Osorio
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja S/n, Granada, 18071, Spain.
| | - Modesto T López-López
- University of Granada, Faculty of Science, Applied Physics Department, Fuente Nueva S/n, Granada, 18071, Spain
| | - Antonio L Medina-Castillo
- NanoMyP, Spin-Off Enterprise from University of Granada, Edificio BIC-Granada, Avda. Innovación 1, Armilla, Granada, 18016, Spain
| | - Álvaro Carrasco-Carmona
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja S/n, Granada, 18071, Spain
| | - Raquel Osorio
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja S/n, Granada, 18071, Spain
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Toledano M, Muñoz-Soto E, Aguilera FS, Osorio E, Pérez-Álvarez MC, García-Menocal JAD, Toledano-Osorio M, Osorio R. The mineralizing effect of zinc oxide-modified hydroxyapatite-based sealer on radicular dentin. Clin Oral Investig 2019; 24:285-299. [DOI: 10.1007/s00784-019-02938-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/02/2019] [Indexed: 11/30/2022]
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22
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The potential of three-dimensional printing technologies to unlock the development of new ‘bio-inspired’ dental materials: an overview and research roadmap. J Prosthodont Res 2019; 63:131-139. [DOI: 10.1016/j.jpor.2018.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/05/2018] [Accepted: 10/26/2018] [Indexed: 11/23/2022]
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23
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Nano-Structured Demineralized Human Dentin Matrix to Enhance Bone and Dental Repair and Regeneration. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9051013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Demineralized dentin matrix (DDM), derived from human teeth, is an excellent scaffold material with exciting bioactive properties to enhance bone and dental tissue engineering efficacy. In this article, first the nano-structure and bioactive components of the dentin matrix were reviewed. Then the preparation methods of DDM and the resulting properties were discussed. Next, the efficacy of DDM as a bone substitute with in vitro and in vivo properties were analyzed. In addition, the applications of DDM in tooth regeneration with promising results were described, and the drawbacks and future research needs were also discussed. With the extraction of growth factors from DDM and the nano-structural properties of DDM, previous studies also broadened the use of DDM as a bioactive carrier for growth factor delivery. In addition, due to its excellent physical and biological properties, DDM was also investigated for incorporation into other biomaterials design and fabrication, yielding great enhancements in hard tissue regeneration efficacy.
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Farina AP, Vidal CMP, Cecchin D, Aguiar TR, Bedran-Russo AK. Structural and biomechanical changes to dentin extracellular matrix following chemical removal of proteoglycans. Odontology 2019; 107:316-323. [PMID: 30710179 DOI: 10.1007/s10266-018-00408-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/24/2018] [Indexed: 11/28/2022]
Abstract
Proteoglycans are biomacromolecules with significant biomineralization and structural roles in the dentin extracellular matrix. This study comprehensively assessed the mechanical properties and morphology of the dentin extracellular matrix following chemical removal of proteoglycans to elucidate the structural roles of proteoglycans in dentin. Dentin extracellular matrix was prepared from extracted teeth after complete tissue demineralization. Chemical removal of proteoglycans was carried-out using guanidine hydrochloride for up to 10 days. The removal of proteoglycans was determined by dimethylmethylene blue colorimetric assay and histological staining analyses using transmission electron microscopy and optical microscopy. The modulus of elasticity of dentin matrix was determined by a 3-point bending test method. Partial removal of proteoglycans induced significant modifications to the dentin matrix, particularly to type I collagen. Removal of proteoglycans significantly decreased the modulus of elasticity of dentin extracellular matrix (p < 0.0001). In conclusion, the subtle disruption of proteoglycans induces pronounced changes to the collagen network packing and the bulk modulus of elasticity of dentin matrix.
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Affiliation(s)
- Ana Paula Farina
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina Street, Room 531, Chicago, IL, 60612, USA.,Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Passo Fundo, RS, Brazil
| | - Cristina M P Vidal
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina Street, Room 531, Chicago, IL, 60612, USA.,Department of Operative Dentistry, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - Doglas Cecchin
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina Street, Room 531, Chicago, IL, 60612, USA.,Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Passo Fundo, RS, Brazil
| | - Thaiane R Aguiar
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina Street, Room 531, Chicago, IL, 60612, USA.,Department of Clinical Dentistry, School of Dentistry, Federal University of Bahia, Salvador, BA, Brazil
| | - Ana K Bedran-Russo
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina Street, Room 531, Chicago, IL, 60612, USA.
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25
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Biomimetic Conditioning of Human Dentin Using Citric Acid. J Endod 2019; 45:45-50. [DOI: 10.1016/j.joen.2018.09.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/20/2018] [Accepted: 09/23/2018] [Indexed: 12/27/2022]
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26
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Toledano M, Osorio R, Pérez-Álvarez MC, Osorio E, Lynch CD, Toledano-Osorio M. A zinc-doped endodontic cement facilitates functional mineralization and stress dissipation at the dentin surface. Med Oral Patol Oral Cir Bucal 2018; 23:e646-e655. [PMID: 30341273 PMCID: PMC6260998 DOI: 10.4317/medoral.22751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/07/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The purpose of this study was to evaluate nanohardness and viscoelastic behavior of dentin surfaces treated with two canal sealer cements for dentin remineralization. MATERIAL AND METHODS Dentin surfaces were subjected to: i) 37% phosphoric acid (PA) or ii) 0.5 M ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite), respectively. Samples were stored in simulated body fluid during 24 h or 21 d. The intertubular and peritubular dentin were evaluated using a nanoindenter to assess nanohardness (Hi). The load/displacement responses were used for the nano-dynamic mechanical analysis to estimate complex modulus (E*) and tan delta (δ). The modulus mapping was obtained by imposing a quasistatic force setpoint to which a sinusoidal force was superimposed. AFM imaging and FESEM analysis were performed. RESULTS After 21 d of storage, dentin surfaces treated with EDTA+calcypatite, PA+calcypatite and EDTA+oxipatite showed viscoelastic discrepancies between peritubular and intertubular dentin, meaning a risk for cracking and breakdown of the surface. At both 24 h and 21 d, tan δ values at intertubular dentin treated with the four treatments performed similar. At 21 d time point, intertubular dentin treated with PA+oxipatite achieved the highest complex modulus and nanohardness, i.e., highest resistance to deformation and functional mineralization, among groups. CONCLUSIONS Intertubular and peritubular dentin treated with PA+oxipatite showed similar values of tan δ after 21 d of storage. This produced a favorable dissipation of energy with minimal energy concentration, preserving the structural integrity at the dentin surface.
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Affiliation(s)
- M Toledano
- University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071 - Granada - Spain,
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Biochemical assessment of nanostructures in human trabecular bone: Proposal of a Raman microspectroscopy based measurements protocol. Injury 2018; 49 Suppl 2:S11-S21. [PMID: 30077357 DOI: 10.1016/j.injury.2018.07.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/26/2018] [Accepted: 07/27/2018] [Indexed: 02/02/2023]
Abstract
BACKGROUND Improvements to the understating of the compositional contributions of bone mineral and organic components to the competence of trabecular bone are crucial. The purpose of this study was to propose a protocol to study biochemical composition of trabecular bone, based on two combined Raman analysis methodologies. MATERIAL AND METHODS Both cluster and single point Raman mappings were obtained, in order to assess bone degeneration associated with aging, disease, or injury, and to help in the evaluation and development of successful therapies. In this study, human trabecular bone has been analysed throughout a) Raman cluster analysis: bone mineral content, carbonate-to-phosphate ratio (both from the mineral components), the crosslinking and nature/secondary structure of collagen (both from the organic components); and b) Single point Raman spectra, where Raman points related to the minerals and organic components were also obtained, both techniques were employed in spectra attained at 400 to 1700 cm-1. RESULTS Multivariate analysis confirmed: 1) the different spectral composition, 2) the existence of centroids grouped by chemical affinity of the various components of the trabecular bone, and 3) the several traces of centroids and distribution of chemical compositional clusters. CONCLUSIONS This study is important, because it delivers a study protocol that provides molecular variations information in both mineral and collagen structure of trabecular bone tissue. This will enable clinicians to benefit knowing the microstructural differences in the bone subjected to degeneration of their patients.
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Sui T, Dluhoš J, Li T, Zeng K, Cernescu A, Landini G, Korsunsky AM. Structure-Function Correlative Microscopy of Peritubular and Intertubular Dentine. MATERIALS 2018; 11:ma11091493. [PMID: 30134596 PMCID: PMC6164774 DOI: 10.3390/ma11091493] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 11/22/2022]
Abstract
Peritubular dentine (PTD) and intertubular dentine (ITD) were investigated by 3D correlative Focused Ion Beam (FIB)-Scanning Electron Microscopy (SEM)-Energy Dispersive Spectroscopy (EDS) tomography, tapping mode Atomic Force Microscopy (AFM) and scattering-type Scanning Near-Field Optical Microscopy (s-SNOM) mapping. The brighter appearance of PTD in 3D SEM-Backscattered-Electron (BSE) imaging mode and the corresponding higher grey value indicate a greater mineral concentration in PTD (~160) compared to ITD (~152). However, the 3D FIB-SEM-EDS reconstruction and high resolution, quantitative 2D map of the Ca/P ratio (~1.8) fail to distinguish between PTD and ITD. This has been further confirmed using nanoscale 2D AFM map, which clearly visualised biopolymers and hydroxyapatite (HAp) crystallites with larger mean crystallite size in ITD (32 ± 8 nm) than that in PTD (22 ± 3 nm). Correlative microscopy reveals that the principal difference between PTD and ITD arises primarily from the nanoscale packing density of the crystallites bonded together by thin biopolymer, with moderate contribution from the chemical composition difference. The structural difference results in the mechanical properties variation that is described by the parabolic stiffness-volume fraction correlation function introduced here. The obtained results benefit a microstructure-based mechano-chemical model to simulate the chemical etching process that can occur in human dental caries and some of its treatments.
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Affiliation(s)
- Tan Sui
- Department of Mechanical Engineering Sciences, University of Surrey, Guildford GU2 7XH, UK.
| | - Jiří Dluhoš
- TESCAN Brno, s.r.o., Libušina třída 1, 623 00 Brno, Czech Republic.
| | - Tao Li
- Department of Mechanical Engineering, National University of Singapore, Singapore 117576, Singapore.
| | - Kaiyang Zeng
- Department of Mechanical Engineering, National University of Singapore, Singapore 117576, Singapore.
| | - Adrian Cernescu
- Neaspec GmbH, Bunsenstr. 5, Martinsried, D-82152 Munich, Germany.
| | - Gabriel Landini
- School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, UK.
| | - Alexander M Korsunsky
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.
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29
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Wang Z, Shen Y, Haapasalo M. Root Canal Wall Dentin Structure in Uninstrumented but Cleaned Human Premolars: A Scanning Electron Microscopic Study. J Endod 2018; 44:842-848. [DOI: 10.1016/j.joen.2018.01.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/27/2018] [Accepted: 01/29/2018] [Indexed: 10/17/2022]
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30
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31
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An B, Daniel Wagner H. The effect of microcracking in the peritubular dentin on the fracture of dentin. J Biomech 2017; 65:125-130. [PMID: 29111203 DOI: 10.1016/j.jbiomech.2017.10.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 10/12/2017] [Accepted: 10/15/2017] [Indexed: 11/28/2022]
Abstract
Dentin is a biocomposite possessing elegant hierarchical structure, which allows it to resist fracture effectively. Despite the considerable efforts to unravel the peculiar fracture behavior of dentin, the effect of microstructural features on the fracture process is largely unknown. In this study, we explore the interaction between the primary crack with crack tip located in intertubular dentin (ITD) and microcracking of peritubular dentin (PTD) ahead of the primary crack. A micromechanical model accounting for the unique composite structure of dentin is developed, and computational simulations are performed. It is found that the microcracking of PTD located in the crack plane in front of the primary crack tip can promote the propagation of the primary crack, increasing the propensity of coalescence of primary crack and microcracks nucleating in PTD. We show that the two-layer microstructure of dentin enables reduction in driving force of primary crack, potentially enhancing fracture toughness. The high stiffness of PTD plays a critical role in reducing the driving force of primary crack and activating microcracking of PTD. It is further identified that the microcracking of PTD arranged parallel to the crack plane with an offset could contribute to the shielding of primary crack.
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Affiliation(s)
- Bingbing An
- Department of Mechanics, Shanghai University, Shanghai 200444, People's Republic of China.
| | - H Daniel Wagner
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
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32
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Stankoska K, Sarram L, Smith S, Bedran-Russo AK, Little CB, Swain MV, Bertassoni LE. Immunolocalization and distribution of proteoglycans in carious dentine. Aust Dent J 2017; 61:288-97. [PMID: 26435422 DOI: 10.1111/adj.12376] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND Collagen type I, proteoglycans (PG) and non-collagenous proteins represent important building blocks of the dentine matrix. While different PGs have been identified in dentine, changes in the distribution of these macromolecules with the progression of caries have been poorly characterized. The aim of this study was to compare the immunolocalization of three small collagen-binding PGs (biglycan, fibromodulin and lumican) as well as collagen (types I and VI) in healthy versus carious dentine. METHODS Longitudinal demineralized sections of extracted teeth were stained with antibodies recognizing specific PG core proteins and collagens, as well as glycosaminoglycans (GAGs) with toluidine blue. RESULTS In healthy dentine, PGs appeared to be more abundant near the tubule walls and directly under the cusps. Conversely, in carious dentine, specific locations appeared to be more prone to PG degradation than others. These degradation patterns were well correlated with the progression of caries into the tissue, and also appeared to trigger interesting morphological changes in the tissue structure, such as the deformation of dentine tubules near highly infected areas and the lower concentration of PG in tertiary dentine. CONCLUSIONS This study presents new insights into the involvement of PGs in the progression of caries.
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Affiliation(s)
- K Stankoska
- Bioengineering, Faculty of Dentistry, The University of Sydney, Sydney, New South Wales, Australia
| | - L Sarram
- Bioengineering, Faculty of Dentistry, The University of Sydney, Sydney, New South Wales, Australia
| | - S Smith
- Raymond Purves Bone and Joint Research Laboratories, Kolling Institute of Medical Research, Institute of Bone and Joint Research, The University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia
| | - A K Bedran-Russo
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois, USA
| | - C B Little
- Raymond Purves Bone and Joint Research Laboratories, Kolling Institute of Medical Research, Institute of Bone and Joint Research, The University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia
| | - M V Swain
- Bioengineering, Faculty of Dentistry, The University of Sydney, Sydney, New South Wales, Australia.,Department of Bioclinical Sciences, Faculty of Dentistry, University of Kuwait, Kuwait
| | - L E Bertassoni
- Bioengineering, Faculty of Dentistry, The University of Sydney, Sydney, New South Wales, Australia.,Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon, USA.,Center for Regenerative Medicine, Oregon Health and Science University, Portland, Oregon, USA
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Bertassoni LE, Swain MV. Removal of dentin non-collagenous structures results in the unraveling of microfibril bundles in collagen type I. Connect Tissue Res 2017; 58:414-423. [PMID: 27657550 PMCID: PMC6214662 DOI: 10.1080/03008207.2016.1235566] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AIMS The structural organization of collagen from mineralized tissues, such as dentin and bone, has been a topic of debate in the recent literature. Recent reports have presented novel interpretations of the complexity of collagen type I at different hierarchical levels and in different tissues. Here, we investigate the nanostructural organization of demineralized dentin collagen following the digestion of non-collagenous components with a trypsin enzyme. MATERIALS AND METHODS Dentin specimens were obtained from healthy third-molars, cut into small cubes, and polished down to 1 µm roughness. Samples were then demineralized with 10% citric acid for 2 min. Selected specimens were further treated with a solution containing 1 mg/ml trypsin for 48 hours at 37 °C (pH 7.9-9.0). Both untreated and trypsin digested samples were analyzed using SDS-PAGE, Field Emission Scanning Electron Microscopy (FE-SEM), and nanoindentation, where surface hardness and creep properties were compared before and after treatments. RESULTS FE-SEM images of demineralized dentin showed the banded morphology of D-periodical collagen type I, which upon enzymatic digestion with trypsin appeared to dissociate longitudinally, consistently unraveling ~20 nm structures (microfibril bundles). Such nanoscale structures, to the best of our knowledge, have not been characterized in dentin previously. Mechanical characterization via nanoindentation showed that the unraveling of such microfibril bundles affected the creep displacement and creep rate of demineralized dentin. CONCLUSION In summary, our results provide novel evidence of the organization of collagen type I from dentin, which may have important implications for the interaction of dental materials with the organic dentin matrix and the mechanical properties of mineralized tissues.
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Affiliation(s)
- Luiz E. Bertassoni
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland OR, USA,Center for Regenerative Medicine, Oregon Health and Science University, Portland OR, USA,Bioengineering Laboratory, Faculty of Dentistry, University of Sydney, Sydney, NSW, Australia
| | - Michael V. Swain
- Bioengineering Laboratory, Faculty of Dentistry, University of Sydney, Sydney, NSW, Australia,Bioclinical Sciences Department, Faculty of Dentistry, University of Kuwait, Kuwait
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Bertassoni LE. Dentin on the nanoscale: Hierarchical organization, mechanical behavior and bioinspired engineering. Dent Mater 2017; 33:637-649. [PMID: 28416222 PMCID: PMC5481168 DOI: 10.1016/j.dental.2017.03.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/09/2017] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Knowledge of the structural organization and mechanical properties of dentin has expanded considerably during the past two decades, especially on a nanometer scale. In this paper, we review the recent literature on the nanostructural and nanomechanical properties of dentin, with special emphasis in its hierarchical organization. METHODS We give particular attention to the recent literature concerning the structural and mechanical influence of collagen intrafibrillar and extrafibrillar mineral in healthy and remineralized tissues. The multilevel hierarchical structure of collagen, and the participation of non-collagenous proteins and proteoglycans in healthy and diseased dentin are also discussed. Furthermore, we provide a forward-looking perspective of emerging topics in biomaterials sciences, such as bioinspired materials design and fabrication, 3D bioprinting and microfabrication, and briefly discuss recent developments on the emerging field of organs-on-a-chip. RESULTS The existing literature suggests that both the inorganic and organic nanostructural components of the dentin matrix play a critical role in various mechanisms that influence tissue properties. SIGNIFICANCE An in-depth understanding of such nanostructural and nanomechanical mechanisms can have a direct impact in our ability to evaluate and predict the efficacy of dental materials. This knowledge will pave the way for the development of improved dental materials and treatment strategies. CONCLUSIONS Development of future dental materials should take into consideration the intricate hierarchical organization of dentin, and pay particular attention to their complex interaction with the dentin matrix on a nanometer scale.
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Affiliation(s)
- Luiz E Bertassoni
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA; Center for Regenerative Medicine, Oregon Health and Science University, School of Medicine, Portland, OR, USA; Department of Biomedical Engineering, Oregon Health and Science University, School of Medicine, Portland, OR, USA.
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35
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Vennat E, Wang W, Genthial R, David B, Dursun E, Gourrier A. Mesoscale porosity at the dentin-enamel junction could affect the biomechanical properties of teeth. Acta Biomater 2017; 51:418-432. [PMID: 28110070 DOI: 10.1016/j.actbio.2017.01.052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 10/20/2022]
Abstract
In this paper, the 3D-morphology of the porosity in dentin is investigated within the first 350μm from the dentin-enamel junction (DEJ) by fluorescence confocal laser scanning microscopy (CLSM). We found that the porous microstructure exhibits a much more complex geometry than classically described, which may impact our fundamental understanding of the mechanical behavior of teeth and could have practical consequences for dental surgery. Our 3D observations reveal numerous fine branches stemming from the tubules which may play a role in cellular communication or mechanosensing during the early stages of dentinogenesis. The effect of this highly branched microstructure on the local mechanical properties is investigated by means of numerical simulations. Under simplified assumptions on the surrounding tissue characteristics, we find that the presence of fine branches negatively affects the mechanical properties by creating local stress concentrations. However, this effect is reduced by the presence of peritubular dentin surrounding the tubules. The porosity was also quantified using the CSLM data and compared to this derived from SEM imaging. A bimodal distribution of channel diameters was found near the DEJ with a mean value of 1.5-2μm for the tubules and 0.3-0.5μm for the fine branches which contribute to 30% of the total porosity (∼1.2%). A gradient in the branching density was observed from the DEJ towards the pulp, independently of the anatomical location. Our work constitutes an incentive towards more elaborate multiscale studies of dentin microstructure to better assess the effect of aging and for the design of biomaterials used in dentistry, e.g. to ensure more efficient bonding to dentin. Finally, our analysis of the tubular network structure provides valuable data to improve current numerical models.
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36
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Toledano M, Osorio R, Osorio E, García-Godoy F, Toledano-Osorio M, Aguilera FS. Advanced zinc-doped adhesives for high performance at the resin-carious dentin interface. J Mech Behav Biomed Mater 2016; 62:247-267. [DOI: 10.1016/j.jmbbm.2016.05.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/04/2016] [Accepted: 05/09/2016] [Indexed: 01/22/2023]
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37
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Clinical Perspective of Electrospun Nanofibers as a Drug Delivery Strategy for Regenerative Endodontics. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s40496-016-0103-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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38
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An B, Wagner HD. Role of microstructure on fracture of dentin. J Mech Behav Biomed Mater 2016; 59:527-537. [DOI: 10.1016/j.jmbbm.2016.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/17/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
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Dorvee JR, Gerkowicz L, Bahmanyar S, Deymier-Black A, Veis A. Chondroitin sulfate is involved in the hypercalcification of the organic matrix of bovine peritubular dentin. Arch Oral Biol 2016; 62:93-100. [PMID: 26656507 PMCID: PMC4806796 DOI: 10.1016/j.archoralbio.2015.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/25/2015] [Accepted: 11/09/2015] [Indexed: 10/22/2022]
Abstract
Apatitic mineral of dentin forms within the collagenous matrix (intertubular dentin, ITD) secreted from the odontoblastic processes (OP). Highly calcified mineral (peritubular dentin, PTD) is deposited at the interface between the ITD and each process membrane, creating a tubular system penetrating the dentin that extends from the dentino-enamel junction to the predentin-dentin junction. We focus on determining the composition of the PTD both with regard to its organic matrix and the inorganic phase. A laser capture technique has been adapted for the isolation of the mineralized PTD free from the ITD, and for the analysis of the PTD by SEM, TEM, and energy dispersive spectrometry (EDS), these data were subsequently compared with similar analyses of intact dentin slices containing ITD bounded-PTD annuli. Elemental line scans reveal clearly marked boundaries between ITD, PTD, and OP components, and illustrate the differences in composition, and topographical surface roughness. The organic matrix of the PTD was shown to be sulfur rich, and further antibody labeling showed the sulfated organic component to be chondroitin sulfate [corrected]. In this PTD organic matrix the S/Ca and Ca/P ratios were distinctly higher than in the ITD, indicating that polysaccharide bound S supplies the anionic counterion facilitating the formation of the apatitic PTD mineral.
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Affiliation(s)
- Jason R Dorvee
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Lauren Gerkowicz
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sara Bahmanyar
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Alix Deymier-Black
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Arthur Veis
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA.
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40
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Abstract
Inspired by the unique microstructure of dentin, in which the hard peritubular dentin surrounding the dentin tubules is embedded in the soft intertubular dentin, we explore the crack propagation in the bioinspired materials with fracture process zone possessing a dentin-like microstructure, i.e. the composite structure consisting of a soft matrix and hard reinforcements with cylindrical voids. A micromechanical model under small-scale yielding conditions is developed, and numerical simulations are performed, showing that the rising resistant curve (R-curve) is observed for crack propagation caused by the plastic collapse of the intervoid ligaments in the fracture process zone. The dentin-like microstructure in the fracture process zone exhibits enhanced fracture toughness, compared with the case of voids embedded in the homogeneous soft matrix. Further computational simulations show that the dentin-like microstructure can retard void growth, thereby promoting fracture toughness. The typical fracture mechanism of the bioinspired materials with fracture process zone possessing the dentin-like structure is void by void growth, while it is the multiple void interaction in the case of voids in the homogeneous matrix. Based on the results, we propose a bioinspired material design principle, which is that the combination of a hard inner material encompassing voids and a soft outer material in the fracture process zone can give rise to exceptional fracture toughness, achieving damage tolerance. It is expected that the proposed design principle could shed new light on the development of novel man-made engineering materials.
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Affiliation(s)
- Bingbing An
- Department of Mechanics, Shanghai University, Shanghai 200444, People's Republic of China. Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai, 200072, People's Republic of China
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Leme AA, Vidal CMP, Hassan LS, Bedran-Russo AK. Potential role of surface wettability on the long-term stability of dentin bonds after surface biomodification. J Biomech 2015; 48:2067-71. [PMID: 25869721 DOI: 10.1016/j.jbiomech.2015.03.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 02/17/2015] [Accepted: 03/13/2015] [Indexed: 11/16/2022]
Abstract
Degradation of the adhesive interface contributes to the failure of resin composite restorations. The hydrophilicity of the dentin matrix during and after bonding procedures may result in an adhesive interface that is more prone to degradation over time. This study assessed the effect of chemical modification of the dentin matrix on the wettability and the long-term reduced modulus of elasticity (Er) of adhesive interfaces. Human molars were divided into groups according to the priming solutions: distilled water (control), 6.5% Proanthocyanidin-rich grape seed extract (PACs), 5.75% 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/1.4% n-hydroxysuccinimide (EDC/NHS) and 5% Glutaraldehyde (GA). The water-surface contact angle was assessed before and after chemical modification of the dentin matrix. The demineralized dentin surface was treated with the priming solutions and restored with One Step Plus (OS) and Single Bond Plus (SB) and resin composite. Er of the adhesive, hybrid layer and underlying dentin was evaluated after 24h and 30 months in artificial saliva. The dentin hydrophilicity significantly decreased after application of the priming solutions. Aging significantly decreased Er in the hybrid layer and underlying dentin of control groups. Er of GA groups remained stable over time at the hybrid layer and underlying dentin. Significant higher Er was observed for PACs and EDC/NHS groups at the hybrid layer after 24h. The decreased hydrophilicity of the modified dentin matrix likely influence the immediate mechanical properties of the hybrid layer. Dentin biomodification prevented substantial aging at the hybrid layer and underlying dentin after 30 months storage.
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Affiliation(s)
- Ariene A Leme
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Cristina M P Vidal
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Lina Saleh Hassan
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Ana K Bedran-Russo
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612, USA.
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Bertassoni LE, Swain MV. The contribution of proteoglycans to the mechanical behavior of mineralized tissues. J Mech Behav Biomed Mater 2014; 38:91-104. [DOI: 10.1016/j.jmbbm.2014.06.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 06/12/2014] [Accepted: 06/14/2014] [Indexed: 10/25/2022]
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Stock S, Deymier-Black A, Veis A, Telser A, Lux E, Cai Z. Bovine and equine peritubular and intertubular dentin. Acta Biomater 2014; 10:3969-77. [PMID: 24911530 DOI: 10.1016/j.actbio.2014.05.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/15/2014] [Accepted: 05/23/2014] [Indexed: 10/25/2022]
Abstract
Dentin contains 1-2μm diameter tubules extending from the pulp cavity to near the junction with enamel. Peritubular dentin (PTD) borders the tubule lumens and is surrounded by intertubular dentin (ITD). Differences in PTD and ITD composition and microstructure remain poorly understood. Here, a (∼200nm)(2), 10.1keV synchrotron X-ray beam maps X-ray fluorescence and X-ray diffraction simultaneously around tubules in 15-30μm thick bovine and equine specimens. Increased Ca fluorescence surrounding tubule lumens confirms that PTD is present, and the relative intensities in PTD and ITD correspond to carbonated apatite (cAp) volume fraction of ∼0.8 in PTD vs. 0.65 assumed for ITD. In the PTD near the lumen edges, Zn intensity is strongly peaked, corresponding to a Zn content of ∼0.9mgg(-1) for an assumed concentration of ∼0.4mgg(-1) for ITD. In the equine specimen, the Zn K-edge position indicates that Zn(2+) is present, similar to bovine dentin (Deymier-Black et al., 2013), and the above edge structure is consistent with spectra from macromolecules related to biomineralization. Transmission X-ray diffraction shows only cAp, and the 00.2 diffraction peak (Miller-Bravais indices) width is constant from ITD to the lumen edge. The cAp 00.2 average preferred orientation is axisymmetric (about the tubule axis) in both bovine and equine dentin, and the axisymmetric preferred orientation continues from ITD through the PTD to the tubule lumen. These data indicate that cAp structure does not vary from PTD to ITD.
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Dorvee JR, Deymier-Black A, Gerkowicz L, Veis A. Peritubular dentin, a highly mineralized, non-collagenous, component of dentin: isolation and capture by laser microdissection. Connect Tissue Res 2014; 55 Suppl 1:9-14. [PMID: 25158171 DOI: 10.3109/03008207.2014.923876] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We demonstrate the capability and technique to perform microdissection and isolation of select regions of untreated, mineralized dentin using laser capture. Dentin is a complex, non-homogeneous tissue comprised of a mineralized collagenous matrix (intertubular dentin [ITD]), odontoblastic processes (ODPs), a void space (tubules) that forms within the ITD left behind by the retraction of ODPs during dentin maturation, and a highly mineralized non-collagenous component that exists at the interface between the tubules and ITD known as peritubular dentin (PTD). PTD forms as the dentin matures. The ODPs retract toward the direction of the pulp; leaving very little PTD at either the DEJ or near the pulp. Statistical analysis of thin cross-sections of coronal bovine dentin imaged by light microscopy reveal that the area occupied by PTD >50%. To examine the nature of PTD and its relation to both the tubules and ITD, we devised a series of steps to carefully prepare sections of coronal bovine dentin so that areas of the dentin tissue could be cut and isolated for further analysis. We demonstrate that it is possible to selectively isolate targeted regions of dentin for analysis and that high resolution analysis of such sections can be performed using electron microscopy. Results show that the mineralized PTD has a different texture than mineralized ITD and that there is a distinct boundary between the PTD and the ITD. Selective isolation of mineralized tissue components for further analytical study opens the door for the investigation of similar enigmatic mineralized structures.
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Affiliation(s)
- Jason R Dorvee
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University , Chicago, IL , USA
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Bedran-Russo AK, Pauli GF, Chen SN, McAlpine J, Castellan CS, Phansalkar RS, Aguiar TR, Vidal CMP, Napotilano JG, Nam JW, Leme AA. Dentin biomodification: strategies, renewable resources and clinical applications. Dent Mater 2013; 30:62-76. [PMID: 24309436 DOI: 10.1016/j.dental.2013.10.012] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/20/2013] [Accepted: 10/30/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications. METHODS The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications. In addition, new data is presented on laboratorial methods for the standardization of proanthocyanidin-rich preparations as a renewable source of plant-derived biomodification agents. RESULTS Biomodification agents can be categorized as physical methods and chemical agents. Synthetic and naturally occurring chemical strategies present distinctive mechanism of interaction with the tissue. Initially thought to be driven only by inter- or intra-molecular collagen induced non-enzymatic cross-linking, multiple interactions with other dentin components are fundamental for the long-term biomechanics and biostability of the tissue. Oligomeric proanthocyanidins show promising bioactivity, and their chemical complexity requires systematic evaluation of the active compounds to produce a fully standardized intervention material from renewable resource, prior to their detailed clinical evaluation. SIGNIFICANCE Understanding the hierarchical structure of dentin and the targeting effect of the bioactive compounds will establish their use in both dentin-biomaterials interface and caries management.
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Affiliation(s)
- Ana K Bedran-Russo
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA.
| | - Guido F Pauli
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Shao-Nong Chen
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - James McAlpine
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Carina S Castellan
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA; Department of Biochemistry and Dental Biomaterials, School of Dentistry, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Rasika S Phansalkar
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Thaiane R Aguiar
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Cristina M P Vidal
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA
| | - José G Napotilano
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Joo-Won Nam
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Ariene A Leme
- Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA
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Sowmya S, Bumgardener JD, Chennazhi KP, Nair SV, Jayakumar R. Role of nanostructured biopolymers and bioceramics in enamel, dentin and periodontal tissue regeneration. Prog Polym Sci 2013. [DOI: 10.1016/j.progpolymsci.2013.05.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Eltit F, Ebacher V, Wang R. Inelastic deformation and microcracking process in human dentin. J Struct Biol 2013; 183:141-8. [DOI: 10.1016/j.jsb.2013.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/16/2013] [Accepted: 04/01/2013] [Indexed: 11/28/2022]
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Campos MJDS, de Albuquerque EG, Pinto BCH, Húngaro HM, Gravina MA, Fraga MR, Vitral RWF. The role of orthodontic tooth movement in bone and root mineral density: a study of patients submitted and not submitted to orthodontic treatment. Med Sci Monit 2013. [PMID: 23197239 PMCID: PMC3560800 DOI: 10.12659/msm.883604] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Background Orthodontic force application to the teeth is responsible for a series of biological responses in the bone and dentin, which lead to some alterations of the mineral density of the tissues. Our objective was determine, through cone-beam computed tomography (CBCT), the mineral density of the apical third of the roots of the upper central incisors and of the periapical bone portion surrounding these teeth, in patients submitted to orthodontic treated and untreated individuals. Material/Methods 30 untreated individuals and 15 treated ones (treatment cessation at least 1 year before the study) underwent CBCT. Mineral density was assessed in the apical third of the root of the upper central incisors and in the alveolar bone in the periapical region of these teeth. In order to reduce CBCT-related mineral density variability, we standardized the cone-beam tomography device, the image-acquisition settings and the field of view positioning and size. Student’s t test was used for the analyses. Results bone mineral density (BMD) and root mineral density (RMD), in Hounsfield Units, were 674.84 and 1282.26 for the untreated group and 630.28 and 1370.29 for the treated group, respectively. The differences between the group means were statistically significant for RMD (p<0.05). Conclusions untreated individuals had a significant lower mean RMD in comparison with those submitted to orthodontic treatment.
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Pelin IM, Trunfio-Sfarghiu AM, Farge P, Piednoir A, Pirat C, Ramos SMM. Multiscale characterization of partially demineralized superficial and deep dentin surfaces. Eur J Oral Sci 2013; 121:341-8. [DOI: 10.1111/eos.12058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Irina M. Pelin
- Laboratory of Natural Polymers; Bioactive and Biocompatible Materials; Petru Poni Institute of Macromolecular Chemistry of Romanian Academy; Iasi; Romania
| | - Ana-Maria Trunfio-Sfarghiu
- Laboratory of Contact and Structural Mechanics; University of Lyon 1; CNRS; INSA-Lyon; UMR 5259; Villeurbanne; France
| | | | - Agnes Piednoir
- Laboratory of Condensed Matter Physics and Nanostructures; University of Lyon 1; CNRS; UMR 5586; Villeurbanne; France
| | - Christophe Pirat
- Laboratory of Condensed Matter Physics and Nanostructures; University of Lyon 1; CNRS; UMR 5586; Villeurbanne; France
| | - Stella M. M. Ramos
- Laboratory of Condensed Matter Physics and Nanostructures; University of Lyon 1; CNRS; UMR 5586; Villeurbanne; France
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Cloitre T, Panayotov IV, Tassery H, Gergely C, Levallois B, Cuisinier FJG. Multiphoton imaging of the dentine-enamel junction. JOURNAL OF BIOPHOTONICS 2013; 6:330-337. [PMID: 22815209 DOI: 10.1002/jbio.201200065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 06/21/2012] [Accepted: 06/22/2012] [Indexed: 06/01/2023]
Abstract
Multiphoton microscopy has been used to reveal structural details of dentine and enamel at the dentin-enamel junction (DEJ) based on their 2-photon excited fluorescence (2PEF) emission and second harmonic generation (SHG). In dentine tubule 2PEF intensity varies due to protein content variation. Intertubular dentin produces both SHG and 2PEF signals. Tubules are surrounded by a thin circular zone with a lower SHG signal than the bulk dentine and the presence of collagen fibers perpendicular to the tubule longitudinal axis is indicated by strong SHG responses. The DEJ appears as a low intensity line on the 2PEF images and this was never previously reported. The SHG signal is completely absent for enamel and aprismatic enamel shows a homogeneous low 2PEF signal contrary to prismatic enamel. The SHG intensity of mantle dentine is increasing from the dentine-enamel junction in the first 12 μm indicating a progressive presence of fibrillar collagen and corresponding to the more external part of mantle dentine where matrix metallo-proteases accumulate. The high information content of multiphoton images confirms the huge potential of this method to investigate tooth structures in physiological and pathological conditions.
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Affiliation(s)
- Thierry Cloitre
- Université Montpellier 2, Laboratoire Charles Coulomb UMR 5221, F-34095 Montpellier, France
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