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Sugii H, Yoshida S, Albougha MS, Hamano S, Hasegawa D, Itoyama T, Obata J, Kaneko H, Minowa F, Tomokiyo A, Maeda H. 4-META/MMA-TBB resin containing nano hydroxyapatite induces the healing of periodontal tissue repair in perforations at the pulp chamber floor. Cell Biochem Funct 2024; 42:e4058. [PMID: 38783647 DOI: 10.1002/cbf.4058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/12/2024] [Accepted: 05/12/2024] [Indexed: 05/25/2024]
Abstract
We aimed to evaluate the materials based on 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate tri-n-butylborane (Super-bond [SB]) and nano hydroxyapatite (naHAp) for the repair of perforation at pulp chamber floor (PPF) in vitro and in vivo models. SB and naHAp were mixed in the mass ratio of 10% or 30% to produce naHAp/SB. Human periodontal ligament stem cells (HPDLSCs) were cultured on resin discs of SB or naHAp/SB to analyze the effects of naHAp/SB on cell adhesion, proliferation, and cementoblastic differentiation. A rat PPF model was treated with SB or naHAp/SB to examine the effects of naHAp/SB on the healing of defected cementum and periodontal ligament (PDL) at the site of PPF. HPDLSCs were spindle-shaped and adhered to all resin discs. Changing the resin from SB to naHAp/SB did not significantly alter cell proliferation. Both 10% and 30% naHAp/SB were more effective than SB in promoting cementoblastic differentiation of HPDLSCs. In the rat PPF model, 30% naHAp/SB was more effective than SB in promoting the formation Sharpey's fiber-like structures with expression of the PDL-related marker and cementum-like structures with expression of cementum-related markers. In conclusion, 30% naHAp/SB can be the new restorative material for PPF because it exhibited the abilities of adhering to dentin and healing of defected periodontal tissue.
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Affiliation(s)
- Hideki Sugii
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | | | - Mhd Safwan Albougha
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Sayuri Hamano
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
- OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Daigaku Hasegawa
- Department of Endodontology, Kyushu University Hospital, Fukuoka, Japan
| | - Tomohiro Itoyama
- Department of Endodontology, Kyushu University Hospital, Fukuoka, Japan
| | - Junko Obata
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Hiroshi Kaneko
- Department of Endodontology, Kyushu University Hospital, Fukuoka, Japan
| | - Fumiko Minowa
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Atsushi Tomokiyo
- Restorative Dentistry, Faculty of Dental Medicine, Hokkaido University, Fukuoka, Japan
| | - Hidefumi Maeda
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
- Department of Endodontology, Kyushu University Hospital, Fukuoka, Japan
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Nicklisch N, Hinrichs C, Palaske L, Vach W, Alt KW. Variability in human tooth cementum thickness reflecting functional processes. J Periodontal Res 2024; 59:408-419. [PMID: 38126232 DOI: 10.1111/jre.13226] [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: 06/26/2023] [Revised: 11/19/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE The aim of this study was to investigate the thickness of acellular extrinsic fibre cementum (AEFC) at four root positions of anterior and posterior teeth with special focus on functional aspects. Furthermore, the correlations between cementum thickness and chronological age and sex are investigated. BACKGROUND While numerous studies confirm continuous cementum apposition with age, masticatory forces as well as physiological and orthodontically induced tooth movements also have the potential to affect tooth cementum thickness. MATERIALS AND METHODS Undecalcified teeth were embedded in resin and transverse-sectioned in the cervical third of the root. Two sections per root were selected, and digital images at four positions were obtained (mesial, distal, oral, and vestibular) using light microscopy. The AEFC thickness of 99 teeth (anterior = 66, posterior = 33, male = 54, female = 45) were measured in both sections. The differences in mean values between root positions and the association of root position variation with tooth type, age, sex, and subject as well as the overall effects of age and sex were analysed using a mixed model. RESULTS First incisors and canines showed the greatest mean AFEC thickness, in contrast to premolars which had the lowest values. Differences were found across the four root positions, with a pattern varying considerably between anterior and posterior teeth and between maxilla and mandible in the anterior teeth. An interaction between root position and subject pointed to the existence of an individual component in the variation of AEFC thickness across the four root positions. There was an age trend with an almost linear increase in cementum thickness of 1 μm per year. Overall, females tended to exhibit a significantly lesser AEFC thickness compared to males. CONCLUSIONS Distinct differences in the pattern of thickness values across the four root positions in anterior and posterior teeth support the assumption that the AEFC is strongly affected by functional processes. In addition to sex-specific differences and age-related trends, the root position variation of AEFC thickness varies from individual to individual.
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Affiliation(s)
- Nicole Nicklisch
- Faculty of Medicine and Dentistry, Danube Private University, Krems, Austria
| | | | - Lukas Palaske
- Faculty of Medicine and Dentistry, Danube Private University, Krems, Austria
| | - Werner Vach
- Institute of Prehistory and Archaeological Science, University of Basel, Basel, Switzerland
| | - Kurt W Alt
- Faculty of Medicine and Dentistry, Danube Private University, Krems, Austria
- Institute of Prehistory and Archaeological Science, University of Basel, Basel, Switzerland
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Guo X, Li J, Wu Y, Xu L. Recent advancements in hydrogels as novel tissue engineering scaffolds for dental pulp regeneration. Int J Biol Macromol 2024; 264:130708. [PMID: 38460622 DOI: 10.1016/j.ijbiomac.2024.130708] [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: 12/07/2023] [Revised: 02/22/2024] [Accepted: 03/05/2024] [Indexed: 03/11/2024]
Abstract
Although conventional root canal treatment offers an effective therapeutic solution, it negatively affects the viability of the affected tooth. In recent years, pulp regeneration technology has emerged as a novel method for treating irreversible pulpitis due to its ability to maintain tooth vitality. The successful implementation of this technique depends on scaffolds and transplantation of exogenous stem cells or recruitment of endogenous stem cells. Accordingly, the three-dimensional structure and viscoelastic characteristics of hydrogel scaffolds, which parallel those of the extracellular matrix, have generated considerable interest. Furthermore, hydrogels support the controlled release of regenerative drugs and to load a wide variety of bioactive molecules. By integrating antibacterial agents into the hydrogel matrix and stimulating an immune response, root canal disinfection can be significantly improved and the rate of pulp regeneration can be accelerated. This review aims to provide an overview of the clinical applications of hydrogels that have been reported in the last 5 years, and offer a comprehensive summary of the different approaches that have been utilized for the optimization of hydrogel scaffolds for pulp regeneration. Advancements and challenges in pulp regeneration using hydrogels treating aged teeth are discussed.
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Affiliation(s)
- Xiaofei Guo
- Xiangya Shool of Stomatology, Central South University, Changsha, Hunan, China
| | - Jiaxuan Li
- Xiangya School of Medicine, Central South University, Changsha, Hunan 410083, China
| | - Yong Wu
- Department of Nephrology, The Second Xiangya Hospital, Key Laboratory of Kidney Disease and Blood Purification, Central South University, Changsha, Hunan, China
| | - Laijun Xu
- Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou 510280, China; School of Stomatology, Changsha Medical University, Changsha, Hunan 410219, China.
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Cho DH, Aguayo S, Cartagena-Rivera AX. Atomic force microscopy-mediated mechanobiological profiling of complex human tissues. Biomaterials 2023; 303:122389. [PMID: 37988897 PMCID: PMC10842832 DOI: 10.1016/j.biomaterials.2023.122389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/30/2023] [Accepted: 11/04/2023] [Indexed: 11/23/2023]
Abstract
Tissue mechanobiology is an emerging field with the overarching goal of understanding the interplay between biophysical and biochemical responses affecting development, physiology, and disease. Changes in mechanical properties including stiffness and viscosity have been shown to describe how cells and tissues respond to mechanical cues and modify critical biological functions. To quantitatively characterize the mechanical properties of tissues at physiologically relevant conditions, atomic force microscopy (AFM) has emerged as a highly versatile biomechanical technology. In this review, we describe the fundamental principles of AFM, typical AFM modalities used for tissue mechanics, and commonly used elastic and viscoelastic contact mechanics models to characterize complex human tissues. Furthermore, we discuss the application of AFM-based mechanobiology to characterize the mechanical responses within complex human tissues to track their developmental, physiological/functional, and diseased states, including oral, hearing, and cancer-related tissues. Finally, we discuss the current outlook and challenges to further advance the field of tissue mechanobiology. Altogether, AFM-based tissue mechanobiology provides a mechanistic understanding of biological processes governing the unique functions of tissues.
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Affiliation(s)
- David H Cho
- Section on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Sebastian Aguayo
- Dentistry School, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile; Schools of Engineering, Medicine, and Biological Sciences, Institute for Biological and Medical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexander X Cartagena-Rivera
- Section on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA.
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Luo X, Niu J, Su G, Zhou L, Zhang X, Liu Y, Wang Q, Sun N. Research progress of biomimetic materials in oral medicine. J Biol Eng 2023; 17:72. [PMID: 37996886 PMCID: PMC10668381 DOI: 10.1186/s13036-023-00382-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/02/2023] [Indexed: 11/25/2023] Open
Abstract
Biomimetic materials are able to mimic the structure and functional properties of native tissues especially natural oral tissues. They have attracted growing attention for their potential to achieve configurable and functional reconstruction in oral medicine. Though tremendous progress has been made regarding biomimetic materials, significant challenges still remain in terms of controversy on the mechanism of tooth tissue regeneration, lack of options for manufacturing such materials and insufficiency of in vivo experimental tests in related fields. In this review, the biomimetic materials used in oral medicine are summarized systematically, including tooth defect, tooth loss, periodontal diseases and maxillofacial bone defect. Various theoretical foundations of biomimetic materials research are reviewed, introducing the current and pertinent results. The benefits and limitations of these materials are summed up at the same time. Finally, challenges and potential of this field are discussed. This review provides the framework and support for further research in addition to giving a generally novel and fundamental basis for the utilization of biomimetic materials in the future.
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Affiliation(s)
- Xinyu Luo
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Jiayue Niu
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Guanyu Su
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Linxi Zhou
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- College of Stomatology, Shanghai Jiao Tong University, Shanghai, 200011, China.
- National Center for Stomatology, Shanghai, 200011, China.
- National Clinical Research Center for Oral Diseases, Shanghai, 200011, China.
- Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China.
| | - Xue Zhang
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Ying Liu
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Qiang Wang
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Ningning Sun
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China.
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Dederichs M, Joedecke P, Weber CT, Guentsch A. Functional Load Capacity of Teeth with Reduced Periodontal Support: A Finite Element Analysis. Bioengineering (Basel) 2023; 10:1330. [PMID: 38002454 PMCID: PMC10669356 DOI: 10.3390/bioengineering10111330] [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: 09/14/2023] [Revised: 10/25/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
The purpose of this study was to investigate the functional load capacity of the periodontal ligament (PDL) in a full arch maxilla and mandible model using a numerical simulation. The goal was to determine the functional load pattern in multi- and single-rooted teeth with full and reduced periodontal support. CBCT data were used to create 3D models of a maxilla and mandible. The DICOM dataset was used to create a CAD model. For a precise description of the surfaces of each structure (enamel, dentin, cementum, pulp, PDL, gingiva, bone), each tooth was segmented separately, and the biomechanical characteristics were considered. Finite Element Analysis (FEA) software computed the biomechanical behavior of the stepwise increased force of 700 N in the cranial and 350 N in the ventral direction of the muscle approach of the masseter muscle. The periodontal attachment (cementum-PDL-bone contact) was subsequently reduced in 1 mm increments, and the simulation was repeated. Quantitative (pressure, tension, and deformation) and qualitative (color-coded images) data were recorded and descriptively analyzed. The teeth with the highest load capacities were the upper and lower molars (0.4-0.6 MPa), followed by the premolars (0.4-0.5 MPa) and canines (0.3-0.4 MPa) when vertically loaded. Qualitative data showed that the areas with the highest stress in the PDL were single-rooted teeth in the cervical and apical area and molars in the cervical and apical area in addition to the furcation roof. In both single- and multi-rooted teeth, the gradual reduction in bone levels caused an increase in the load on the remaining PDL. Cervical and apical areas, as well as the furcation roof, are the zones with the highest functional stress. The greater the bone loss, the higher the mechanical load on the residual periodontal supporting structures.
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Affiliation(s)
- Marco Dederichs
- Policlinic of Prosthetic Dentistry and Material Science, Centre for Dental Medicine, Jena University Hospital, D-07743 Jena, Germany;
| | - Paul Joedecke
- Department of Engineering and Industrial Design, Magdeburg-Stendal University of Applied Sciences, D-39114 Magdeburg, Germany (C.-T.W.)
| | - Christian-Toralf Weber
- Department of Engineering and Industrial Design, Magdeburg-Stendal University of Applied Sciences, D-39114 Magdeburg, Germany (C.-T.W.)
| | - Arndt Guentsch
- School of Dentistry, Marquette University, Milwaukee, WI 53233, USA
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Thompson LA, Chen H. Physiology of Aging of Older Adults: Systemic and Oral Health Considerations-2021 Update. Clin Geriatr Med 2023; 39:225-234. [PMID: 37045530 DOI: 10.1016/j.cger.2023.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Most oral health care providers encounter older adults in their practices and can play a critical role in supporting independence and quality of life for this aging cohort. Physiologic and structural oral cavity changes associated with normal aging may affect the presentation and oral health care of older adults. This article reviews the normative aging of dentition and oral structures and physiologic changes associated with normal aging, including cardiovascular, metabolic, and musculoskeletal changes, and how they may affect oral health. Oral health providers should be aware of normal aging processes when they plan care or schedule procedures for older adults.
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Affiliation(s)
- Lisa A Thompson
- Geriatric Dental Fellowship, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115, USA
| | - Helen Chen
- Hebrew SeniorLife, Boston, MA, USA; Division of Gerontology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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8
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Moga RA, Olteanu CD, Daniel BM, Buru SM. Finite Elements Analysis of Tooth-A Comparative Analysis of Multiple Failure Criteria. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:ijerph20054133. [PMID: 36901151 PMCID: PMC10002102 DOI: 10.3390/ijerph20054133] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 02/19/2023] [Accepted: 02/23/2023] [Indexed: 06/01/2023]
Abstract
Herein Finite elements analysis (FEA) study assesses the adequacy and accuracy of five failure criteria (Von Mises (VM), Tresca, maximum principal (S1), minimum principal (S3), and Hydrostatic pressure) for the study of tooth as a structure (made of enamel, dentin, and cement), along with its stress absorption-dissipation ability. Eighty-one 3D models of the second lower premolar (with intact and 1-8 mm reduced periodontium) were subjected to five orthodontic forces (intrusion, extrusion, tipping, rotation, and translation) of 0.5 N (approx. 50 gf) (in a total of 405 FEA simulations). Only the Tresca and VM criteria showed biomechanically correct stress display during the 0-8 mm periodontal breakdown simulation, while the other three showed various unusual biomechanical stress display. All five failure criteria displayed comparable quantitative stress results (with Tresca and VM producing the highest of all), showing the rotational and translational movements to produce the highest amount of stress, while intrusion and extrusion, the lowest. The tooth structure absorbed and dissipated most of the stress produced by the orthodontic loads (from a total of 0.5 N/50 gf only 0.125 N/12.5 gf reached PDL and 0.01 N/1 gf the pulp and NVB). The Tresca criterion seems to be more accurate than Von Mises for the study of tooth as structure.
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Affiliation(s)
- Radu Andrei Moga
- Department of Cariology, Endodontics and Oral Pathology, School of Dental Medicine, University of Medicine and Pharmacy Iuliu Hatieganu, Str. Motilor 33, 400001 Cluj-Napoca, Romania
| | - Cristian Doru Olteanu
- Department of Orthodontics, School of Dental Medicine, University of Medicine and Pharmacy Iuliu Hatieganu, Str. Avram Iancu 31, 400083 Cluj-Napoca, Romania
| | - Botez Mircea Daniel
- Department of Structural Mechanics, School of Civil Engineering, Technical University of Cluj-Napoca, Str. Memorandumului 28, 400114 Cluj-Napoca, Romania
| | - Stefan Marius Buru
- Department of Structural Mechanics, School of Civil Engineering, Technical University of Cluj-Napoca, Str. Memorandumului 28, 400114 Cluj-Napoca, Romania
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Dorado S, Arias A, Jimenez-Octavio JR. Biomechanical Modelling for Tooth Survival Studies: Mechanical Properties, Loads and Boundary Conditions-A Narrative Review. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7852. [PMID: 36363451 PMCID: PMC9657341 DOI: 10.3390/ma15217852] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 06/16/2023]
Abstract
Recent biomechanical studies have focused on studying the response of teeth before and after different treatments under functional and parafunctional loads. These studies often involve experimental and/or finite element analysis (FEA). Current loading and boundary conditions may not entirely represent the real condition of the tooth in clinical situations. The importance of homogenizing both sample characterization and boundary conditions definition for future dental biomechanical studies is highlighted. The mechanical properties of dental structural tissues are presented, along with the effect of functional and parafunctional loads and other environmental and biological parameters that may influence tooth survival. A range of values for Young's modulus, Poisson ratio, compressive strength, threshold stress intensity factor and fracture toughness are provided for enamel and dentin; as well as Young's modulus and Poisson ratio for the PDL, trabecular and cortical bone. Angles, loading magnitude and frequency are provided for functional and parafunctional loads. The environmental and physiological conditions (age, gender, tooth, humidity, etc.), that may influence tooth survival are also discussed. Oversimplifications of biomechanical models could end up in results that divert from the natural behavior of teeth. Experimental validation models with close-to-reality boundary conditions should be developed to compare the validity of simplified models.
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Affiliation(s)
- Saúl Dorado
- Department of Mechanical Engineering, Escuela Técnica Superior de Ingeniería ICAI, Universidad Pontificia Comillas, 28015 Madrid, Spain
| | - Ana Arias
- Department of Conservative and Prosthetic Dentistry, School of Dentistry, Complutense University, 28040 Madrid, Spain
| | - Jesus R. Jimenez-Octavio
- Instituto de Investigación Tecnológica, Escuela Técnica Superior de Ingeniería ICAI, Universidad Pontificia Comillas, 28015 Madrid, Spain
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10
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Hinrichs C, Nicklisch N, Mardare CC, Orechovski B, Hassel AW, Kleber C, Alt KW. Incremental lines in human acellular tooth cementum - new insights by SEM analysis. Ann Anat 2022; 243:151933. [PMID: 35307556 DOI: 10.1016/j.aanat.2022.151933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/05/2022] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Tooth cementum covers the surface of the root dentine and is produced and laid down in thin layers continuously throughout life. Functionally, different types of tooth cementum can be distinguished, which can be roughly divided into acellular (primary cementum) and cellular (secondary cementum) forms. One main type is acellular extrinsic fibre cementum (AEFC), which covers the cervical and middle third of the root. Light microscopic examinations of transverse sections of AEFC show lamellar patterns of alternating light and dark lines called growth or incremental lines. Following mammalian research, a seasonal rhythm of incremental line formation is also assumed in humans. Previous attempts at visualising incremental lines in the AEFC by scanning electron microscopy (SEM) were not particularly successful. The aim of the present study was to detect incremental lines in the AEFC and to analyse their underlying structure by SEM. METHODS For this purpose, non-embedded and resin-embedded transverse and longitudinal sections of three single-rooted teeth obtained from different patients were investigated. The thin sections were not pre-treated (e.g. by etching, grinding or coating). RESULTS Lamellar structures, which could be identified as incremental lines, were detectable in both transverse and longitudinal sections, with transverse orientation in the cross-section and longitudinal orientation in the longitudinal section. The lamellar pattern was created by broad fibre-rich layers alternating with narrow fibre-poor layers. The orientation of the collagen fibres changed from layer to layer from transverse to radial direction. The visibility of the layered structure discovered varied significantly. CONCLUSIONS The study demonstrate that it is possible, in principle, to detect incremental lines in AEFC and to identify their basic structure using SEM. Our results suggest that the density and orientation of the fibres play an essential role in the formation of incremental lines. Functional aspects seem to be of particular importance.
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Affiliation(s)
| | - Nicole Nicklisch
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria.
| | - Cezarina C Mardare
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria.
| | - Bernhard Orechovski
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria.
| | - Achim W Hassel
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria.
| | - Christoph Kleber
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria.
| | - Kurt W Alt
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Prehistory and Archaeological Science, University of Basel, Spalenring 145, 4055 Basel; Switzerland.
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11
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Sterkenburgh T, Schulz-Kornas E, Nowak M, Staszyk C. A Computerized Simulation of the Occlusal Surface in Equine Cheek Teeth: A Simplified Model. Front Vet Sci 2022; 8:789133. [PMID: 35047585 PMCID: PMC8761981 DOI: 10.3389/fvets.2021.789133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Equine mastication, as well as dental wear patterns, is highly important for the development of treatments in equine dentistry. During the last decades, the stress and strain distributions of equine teeth have been successfully simulated using finite element analysis. Yet, to date, there is no simulation available for dental tooth wear in equines. In this study, we developed a simplified two-dimensional computer simulation of dental wear. It provides a first tentative explanation for the development of the marked physiological inclination of the occlusal surface and for pathological conditions such as sharp enamel points in equine cheek teeth. The mechanical properties of the dental structures as well as the movement of the mandible during the equine chewing cycle were simulated according to previously published data. The simulation setup was optimized in preliminary test runs. Further simulations were conducted varying the lateral excursion of the mandible and the presence or absence of incisor contact during the chewing cycle. The results of simulations showed clear analogies to tooth wear patterns in living equids, including the formation of wear abnormalities. Our analysis indicates that small variations in the pattern of movement during the masticatory cycle, as well as incisor contacts, are leading to marked changes in the occlusal tooth wear patterns. This opens new research avenues to better understand the development of dental wear abnormalities in equines and might have serious implications on captive animal health, welfare, and longevity.
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Affiliation(s)
- Tomas Sterkenburgh
- Veterinary Practice Dr. M. Nowak, Equine Clinic Meerbusch, Meerbusch, Germany
| | - Ellen Schulz-Kornas
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Department of Cariology, Endodontology and Periodontology, University of Leipzig, Leipzig, Germany
| | - Michael Nowak
- Veterinary Practice Dr. M. Nowak, Equine Clinic Meerbusch, Meerbusch, Germany
| | - Carsten Staszyk
- Institute of Veterinary-Anatomy, Histology and Embryology, Justus-Liebig-University Gießen, Giessen, Germany
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Andresen AK, Jonsson MV, Sulo G, Thelen DS, Shi XQ. Radiographic features in 2D imaging as predictors for justified CBCT examinations of canine-induced root resorption. Dentomaxillofac Radiol 2022; 51:20210165. [PMID: 34324382 PMCID: PMC8693324 DOI: 10.1259/dmfr.20210165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES This retrospective observational study aimed to evaluate the diagnostic accuracy of two-dimensional radiographs on canine-induced root resorption (CIRR) in lateral incisors and identify predictors of CIRR in patients with impacted maxillary canines (IMC). METHODS Ninety-nine patients aged 9-17 years, with 156 IMCs, were included in the study. All had CBCT-volumes and two-dimensional radiographs consisting of at least one panoramic radiograph. Two radiologists jointly viewed all cases twice. First, radiographic features related to the IMC and possible CIRR were recorded from two-dimensional radiographs. Then, CIRR was determined from CBCT and according to position and extension classified as mild, moderate and severe. RESULTS CIRRs was detected in 80% of lateral incisors (mild: 45%; moderate: 44%; severe: 11%). The sensitivity was generally low at mild and moderate cut-offs (29 and 29%), and somewhat higher for severe (50%). Corresponding specificities were 48%, 63% and 68%. Canine cusp-tip superimposing the lateral incisor's middle third and root/crown ratio >1 was positively associated with mild CIRR, with an odds ratio (OR) of 3.8 and 6.7, respectively. In addition, the root development stage was positively associated with moderate/severe CIRR when the canine root was nearly or fully developed (OR = 3.1). CONCLUSIONS The diagnostic accuracy of two-dimensional radiographs was inadequate for detecting CIRR amongst patients referred for CBCT examinations. Based on our results, none of the suggested two-dimensional radiographic features could predict moderate/severe CIRR except for root development stage. IMC in a later stage of root development seems to be associated with a higher risk of moderate/severe CIRR.
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Affiliation(s)
- Amanda K.H. Andresen
- Department of Clinical Dentistry, Section for Oral and Maxillofacial Radiology, University of Bergen, Norway, United Kingdom
| | | | | | - Dorina S. Thelen
- Oral Health Centre of Expertise in Western Norway, Bergen, Norway, United Kingdom
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13
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Lum JTS, Chan YN, Leung KSY. Current applications and future perspectives on elemental analysis of non-invasive samples for human biomonitoring. Talanta 2021; 234:122683. [PMID: 34364482 DOI: 10.1016/j.talanta.2021.122683] [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: 03/24/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 12/09/2022]
Abstract
Humans are continuously exposed to numerous environmental pollutants including potentially toxic elements. Essential elements play an important role in human health. Abnormal elemental levels in the body, in different forms that existed, have been reported to be correlated with different diseases and environmental exposure. Blood is the conventional biological sample used in human biomonitoring. However, blood samples can only reflect short-term exposure and require invasive sampling, which poses infection risk to individuals. In recent years, the number of research evaluating the effectiveness of non-invasive samples (hair, nails, urine, meconium, breast milk, placenta, cord blood, saliva and teeth) for human biomonitoring is increasing. These samples can be collected easily and provide extra information in addition to blood analysis. Yet, the correlation between the elemental concentration in non-invasive samples and in blood is not well established, which hinders the application of those samples in routine human biomonitoring. This review aims at providing a fundamental overview of analytical methods of non-invasive samples in human biomonitoring. The content covers the sample collection and pretreatment, sample preparation and instrumental analysis. The technical discussions are separated into solution analysis and solid analysis. In the last section, the authors highlight some of the perspectives on the future of elemental analysis in human biomonitoring.
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Affiliation(s)
- Judy Tsz-Shan Lum
- Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Yun-Nam Chan
- Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Kelvin Sze-Yin Leung
- Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region; HKBU Institute of Research and Continuing Education, Shenzhen Virtual University Park, Shenzhen, China.
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14
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Yi Q, Feng X, Zhang C, Wang X, Wu X, Wang J, Cui F, Wang S. Comparison of dynamic mechanical properties of dentin between deciduous and permanent teeth. Connect Tissue Res 2021; 62:402-410. [PMID: 32308055 DOI: 10.1080/03008207.2020.1758684] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Purpose: Even though differences between deciduous and permanent dentin have been widely studied, their dynamic mechanical behavior has never been compared. The objective of the present study was to quantify the differences between deciduous and permanent dentin under cyclic mechanical loading, which is similar to masticatory stress.Materials and Methods: Deciduous and permanent teeth, respectively from children (9 ~ 12 years old) and young people (18 ~ 25 years old), were wet-sectioned perpendicular to the longitudinal axis and the central specimens of coronal dentin were evaluated by nanoscopic dynamic mechanical analysis (nanoDMA).Results: The average storage, loss, and complex moduli, as well as the hardness of deciduous dentin were significantly (p < 0.05) lower than those of permanent dentin. Moreover, the tan δ value of permanent dentin was significantly (p < 0.05) lower than that of deciduous dentin across the loading frequency range, indicating that viscoelastic behavior and loss of elastic energy were significantly reduced in the stiffer permanent dentin. All the nanoDMA responses showed a significant influence of the dynamic loading frequency (p < 0.05): Both deciduous and permanent dentin showed reduced viscoelasticty with increased loading frequencies.Conclusions: Compared with deciduous dentin, permanent dentin exhibits higher stiffness with reduced energy loss during deformation, and therefore superior mechanical characteristics for the mastication process.
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Affiliation(s)
- Qiao Yi
- Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, P. R. China
| | - Xiaoyu Feng
- Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, P. R. China
| | - Chunmei Zhang
- Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, P. R. China
| | - Xiumei Wang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, P. R. China
| | - Xiaoshan Wu
- Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, P. R. China.,Department of Oral and Maxillofacial Surgery, Xiangya Hospital, Central South University, Shangsha, China
| | - Jingsong Wang
- Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, P. R. China.,Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing, P. R. China
| | - Fuzhai Cui
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, P. R. China
| | - Songlin Wang
- Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, P. R. China.,Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing, P. R. China
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15
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Thompson LA, Chen H. Physiology of Aging of Older Adults: Systemic and Oral Health Considerations-2021 Update. Dent Clin North Am 2021; 65:275-284. [PMID: 33641753 DOI: 10.1016/j.cden.2020.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Most oral health care providers encounter older adults in their practices and can play a critical role in supporting independence and quality of life for this aging cohort. Physiologic and structural oral cavity changes associated with normal aging may affect the presentation and oral health care of older adults. This article reviews the normative aging of dentition and oral structures and physiologic changes associated with normal aging, including cardiovascular, metabolic, and musculoskeletal changes, and how they may affect oral health. Oral health providers should be aware of normal aging processes when they plan care or schedule procedures for older adults.
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Affiliation(s)
- Lisa A Thompson
- Geriatric Dental Fellowship, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115, USA
| | - Helen Chen
- Hebrew SeniorLife, Boston, MA, USA; Division of Gerontology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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16
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Liao H, Zhang H, Xiang J, Chen G, Cao Z. The effect of the surgical microscope on the outcome of root scaling. Am J Transl Res 2020; 12:7199-7210. [PMID: 33312360 PMCID: PMC7724328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 10/10/2020] [Indexed: 06/12/2023]
Abstract
The benefits of using a surgical microscope in periodontal therapy were mainly based on subjective statements made by patients or periodontists. We aimed to provide laboratory evidence for the advantages of using a surgical microscope during root scaling on periodontitis teeth. In the present study, the extracted teeth were categorized into four groups: normal teeth (normal control [NC] group), untreated periodontitis teeth (periodontitis control [PC] group), root surface scaled without magnification (macro group), and root surface instrumented with a microscope (micro group). To analyze both the mechanical and biological properties of the root surfaces, we performed nanoindentation in addition to the traditional methods. We found that by using a surgical microscope, we improved the clearance of bacterial deposits and calculi on periodontitis root surfaces. Nanoindentation results revealed that the nanotopography pattern, elastic modulus, and nanohardness of the root surface in the micro group were closest to those in the NC group. The immunofluorescence assay and cell proliferation analyses revealed improved morphology and enhanced adhesion and proliferation of periodontal ligament cells on the root surface in the micro group compared with the macro group. After instrumentation, the expression levels of interleukin-6 and interleukin-8 decreased when compared with the PC group. Our results demonstrated that surgical microscope application could improve the outcomes of periodontal treatment, implying that a surgical microscope can be a powerful tool for periodontists to seek accurate clinical periodontal performance and gain better biocompatibility of the treated root surfaces.
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Affiliation(s)
- Haiqing Liao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
| | - Huihui Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
- Department of Periodontology, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
| | - Junbo Xiang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
- Department of Periodontology, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
| | - Guanting Chen
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
- Department of Periodontology, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
| | - Zhengguo Cao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
- Department of Periodontology, School & Hospital of Stomatology, Wuhan UniversityLuoyu Road, Wuhan 430079, China
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17
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Iohara K, Zayed M, Takei Y, Watanabe H, Nakashima M. Treatment of Pulpectomized Teeth With Trypsin Prior to Transplantation of Mobilized Dental Pulp Stem Cells Enhances Pulp Regeneration in Aged Dogs. Front Bioeng Biotechnol 2020; 8:983. [PMID: 32923438 PMCID: PMC7456913 DOI: 10.3389/fbioe.2020.00983] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/28/2020] [Indexed: 12/20/2022] Open
Abstract
There is an age-dependent decline of pulp regeneration, due to the decline of migration, proliferation, and cell survival of resident stem cells. Trypsin is a proteolytic enzyme clinically used for tissue repair. Here, we investigated the effects of trypsin pretreatment of pulpectomized teeth prior to cell transplantation on pulp regeneration in aged dogs. The amount of regenerated pulp was significantly higher in trypsin-pretreated teeth compared to untreated teeth. Trypsin pretreatment increased the number of cells attached to the dentinal wall that differentiated into odontoblast-like cells. The trypsin receptor, PAR2, was higher in vitro expression in the periodontal ligament cells (PDLCs) from aged dogs compared to those from young. The direct effects of trypsin on aged PDLCs were increased expression of genes related to immunomodulation, cell survival, and extracellular matrix degradation. To examine the indirect effects on microenvironment, highly extracted proteins from aged cementum were identified by proteomic analyses. Western blotting demonstrated that significantly increased fibronectin was released by the trypsin treatment of aged cementum compared to young cementum. The aged cementum extract (CE) and dentin extract (DE) by trypsin treatment increased angiogenesis, neurite extension and migration activities as elicited by fibronectin. Furthermore, the DE significantly increased the mRNA expression of immunomodulatory factors and pulp markers in the aged DPSCs. These results demonstrated the effects of trypsin on the microenvironment in addition to the resident cells including PDLCs in the aged teeth. In conclusion, the potential utility of trypsin pretreatment to stimulate pulp regeneration in aged teeth and the underlying mechanisms were demonstrated.
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Affiliation(s)
- Koichiro Iohara
- Department of Stem Cell Biology and Regenerative Medicine, National Center for Geriatrics and Gerontology, Research Institute, Obu, Japan
| | - Mohammed Zayed
- Department of Stem Cell Biology and Regenerative Medicine, National Center for Geriatrics and Gerontology, Research Institute, Obu, Japan.,Department of Surgery, College of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Yoshifumi Takei
- Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, Nagoya, Japan
| | - Hideto Watanabe
- Institute for Molecular Science of Medicine, Aichi Medical University, Nagakute, Japan
| | - Misako Nakashima
- Department of Stem Cell Biology and Regenerative Medicine, National Center for Geriatrics and Gerontology, Research Institute, Obu, Japan.,Aeras Bio Inc., Air Water Group, Kobe, Japan
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18
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The pararadicular radiolucency with vital pulp: Clinicopathologic features of 21 cemental tears. Oral Surg Oral Med Oral Pathol Oral Radiol 2019; 128:680-689. [DOI: 10.1016/j.oooo.2019.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 07/03/2019] [Accepted: 07/21/2019] [Indexed: 11/18/2022]
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19
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Park CH. Biomaterial-Based Approaches for Regeneration of Periodontal Ligament and Cementum Using 3D Platforms. Int J Mol Sci 2019; 20:E4364. [PMID: 31491973 PMCID: PMC6770383 DOI: 10.3390/ijms20184364] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 02/07/2023] Open
Abstract
Currently, various tissue engineering strategies have been developed for multiple tissue regeneration and integrative structure formations as well as single tissue formation in musculoskeletal complexes. In particular, the regeneration of periodontal tissues or tooth-supportive structures is still challenging to spatiotemporally compartmentalize PCL (poly-ε-caprolactone)-cementum constructs with micron-scaled interfaces, integrative tissue (or cementum) formations with optimal dimensions along the tooth-root surfaces, and specific orientations of engineered periodontal ligaments (PDLs). Here, we discuss current advanced approaches to spatiotemporally control PDL orientations with specific angulations and to regenerate cementum layers on the tooth-root surfaces with Sharpey's fiber anchorages for state-of-the-art periodontal tissue engineering.
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Affiliation(s)
- Chan Ho Park
- Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, Daegu 41940, Korea.
- Institute for Biomaterials Research and Development, Kyungpook National University, Daegu 41940, Korea.
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20
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Bertrand B, Cunha E, Bécart A, Gosset D, Hédouin V. Age at death estimation by cementochronology: Too precise to be true or too precise to be accurate? AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 169:464-481. [DOI: 10.1002/ajpa.23849] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/14/2019] [Accepted: 04/19/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Benoit Bertrand
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
- Muséum national d'Histoire naturelle, Département Homme et EnvironnementUMR 7194 ‐ HNHP, Institut de Paléontologie Humaine F‐75013 Paris France
| | - Eugenia Cunha
- Laboratory of Forensic AnthropologyCentre for Functional Ecology, Department of Life Sciences, University of Coimbra Coimbra Portugal
- National Institute of Legal Medicine and forensic SciencesLargo da Sé Nova Coimbra Portugal
| | - Anne Bécart
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
| | - Didier Gosset
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
| | - Valery Hédouin
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
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21
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Couoh LR. Differences between biological and chronological age-at-death in human skeletal remains: A change of perspective. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2017; 163:671-695. [DOI: 10.1002/ajpa.23236] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 04/05/2017] [Accepted: 04/10/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Lourdes R. Couoh
- Postgraduate Division, Faculty of Philosophy and Literature, Institute of Anthropological Research; The National Autonomous University of Mexico [UNAM]; Coyoacán, Mexico city 04510 Mexico
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22
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Huang L, Salmon B, Yin X, Helms JA. From restoration to regeneration: periodontal aging and opportunities for therapeutic intervention. Periodontol 2000 2016; 72:19-29. [PMID: 27501489 PMCID: PMC6190904 DOI: 10.1111/prd.12127] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
With the march of time our bodies start to wear out: eyesight fades, skin loses its elasticity, teeth and bones become more brittle and injuries heal more slowly. These universal features of aging can be traced back to our stem cells. Aging has a profound effect on stem cells: DNA mutations naturally accumulate over time and our bodies have evolved highly specialized mechanisms to remove these damaged cells. Whilst obviously beneficial, this repair mechanism also reduces the pool of available stem cells and this, in turn, has a dramatic effect on tissue homeostasis and on our rate of healing. Simply put: fewer stem cells means a decline in tissue function and slower healing. Despite this seemingly intractable situation, research over the past decade now demonstrates that some of the effects of aging are reversible. Nobel prize-winning research demonstrates that old cells can become young again, and lessons learned from these experiments-in-a-dish are now being translated into human therapies. Scientists and clinicians around the world are identifying and characterizing methods to activate stem cells to reinvigorate the body's natural regenerative process. If this research in dental regenerative medicine pans out, the end result will be tissue homeostasis and healing back to the levels we appreciated when we were young.
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Affiliation(s)
- Lan Huang
- Orthodontic Department, Stomatology Hospital of Chongqing Medical University; Chongqing Key Laboratory of Oral Disease and Biomedical Sciences; Chongqing Municipal Key Laboratory, Chongqing, 401147, China
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305
| | - Benjamin Salmon
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305
- Dental School, University Paris Descartes PRES Sorbonne Paris Cite, EA 2496, Montrouge, France and AP-HP Odontology Department Bretonneau, Hopitaux Universitaires Paris Nord Val de Seine, Paris, France
| | - Xing Yin
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Jill A. Helms
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305
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23
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Wren AW. Vitreous Materials for Dental Restoration and Reconstruction. BIOCOMPATIBLE GLASSES 2016. [DOI: 10.1007/978-3-319-44249-5_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Effect of proteoglycans at interfaces as related to location, architecture, and mechanical cues. Arch Oral Biol 2015; 63:82-92. [PMID: 26741830 DOI: 10.1016/j.archoralbio.2015.11.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 08/15/2015] [Accepted: 11/24/2015] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Covalently bound functional GAGs orchestrate tissue mechanics through time-dependent characteristics. OBJECTIVE The role of specific glycosaminoglycans (GAGs) at the ligament-cementum and cementum-dentin interfaces within a human periodontal complex were examined. Matrix swelling and resistance to compression under health and modeled diseased states was investigated. MATERIALS AND METHODS The presence of keratin sulfate (KS) and chondroitin sulfate (CS) GAGs at the ligament-cementum and cementum-dentin interfaces in human molars (N=5) was illustrated by using enzymes, atomic force microscopy (AFM), and AFM-based nanoindentation. The change in physical characteristics of modeled diseased states through sequential digestion of keratin sulfate (KS) and chondroitin sulfate (CS) GAGs was investigated. One-way ANOVA tests with P<0.05 were performed to determine significant differences between groups. Additionally, the presence of mineral within the seemingly hygroscopic interfaces was investigated using transmission electron microscopy. RESULTS Immunohistochemistry (N=3) indicated presence of biglycan and fibromodulin small leucine rich proteoglycans at the interfaces. Digestion of matrices with enzymes confirmed the presence of KS and CS GAGs at the interfaces by illustrating a change in tissue architecture and mechanics. A significant increase in height (nm), decrease in elastic modulus (GPa), and tissue deformation rate (nm/s) of the PDL-C attachment site (215±63-424±94nm; 1.5±0.7-0.4±0.2GPa; 21±7-48±22nm/s), and cementum-dentin interface (122±69-360±159nm; 2.9±1.3-0.7±0.3GPa; 18±4-30±6nm/s) was observed. CONCLUSIONS The sequential removal of GAGs indicated loss in intricate structural hierarchy of hygroscopic interfaces. From a mechanics perspective, GAGs provide tissue recovery/resilience. The results of this study provide insights into the role of GAGs toward conserved tooth movement in the socket in response to mechanical loads, and modulation of potentially deleterious strain at tissue interfaces.
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25
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Dorozhkin SV. Calcium orthophosphates (CaPO 4): occurrence and properties. Prog Biomater 2015; 5:9-70. [PMID: 27471662 PMCID: PMC4943586 DOI: 10.1007/s40204-015-0045-z] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/05/2015] [Indexed: 01/02/2023] Open
Abstract
The present overview is intended to point the readers' attention to the important subject of calcium orthophosphates (CaPO4). This type of materials is of the special significance for the human beings because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with CaPO4, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenorthophosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of CaPO4. Similarly, dental caries and osteoporosis might be considered as in vivo dissolution of CaPO4. In addition, natural CaPO4 are the major source of phosphorus, which is used to produce agricultural fertilizers, detergents and various phosphorus-containing chemicals. Thus, there is a great significance of CaPO4 for the humankind and, in this paper, an overview on the current knowledge on this subject is provided.
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Peck CC. Biomechanics of occlusion - implications for oral rehabilitation. J Oral Rehabil 2015; 43:205-14. [DOI: 10.1111/joor.12345] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2015] [Indexed: 11/26/2022]
Affiliation(s)
- C. C. Peck
- Faculty of Dentistry; The University of Sydney; Sydney NSW Australia
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27
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Djomehri SI, Candell S, Case T, Browning A, Marshall GW, Yun W, Lau SH, Webb S, Ho SP. Mineral density volume gradients in normal and diseased human tissues. PLoS One 2015; 10:e0121611. [PMID: 25856386 PMCID: PMC4391782 DOI: 10.1371/journal.pone.0121611] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 02/02/2015] [Indexed: 11/29/2022] Open
Abstract
Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.
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Affiliation(s)
- Sabra I. Djomehri
- Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of San Francisco, San Francisco, California, United States of America
| | - Susan Candell
- Xradia Inc., Pleasanton, California, United States of America
| | - Thomas Case
- Xradia Inc., Pleasanton, California, United States of America
| | - Alyssa Browning
- Xradia Inc., Pleasanton, California, United States of America
| | - Grayson W. Marshall
- Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of San Francisco, San Francisco, California, United States of America
| | - Wenbing Yun
- Xradia Inc., Pleasanton, California, United States of America
| | - S. H. Lau
- Xradia Inc., Pleasanton, California, United States of America
| | - Samuel Webb
- Stanford Synchrotron Radiation Lightsource, Stanford Linear Accelerator Center, Menlo Park, California, United States of America
| | - Sunita P. Ho
- Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of San Francisco, San Francisco, California, United States of America
- * E-mail:
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