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Alnasser M, Alshammari AH, Siddiqui AY, Alothmani OS, Issrani R, Iqbal A, Khattak O, Prabhu N. Tissue Regeneration on Rise: Dental Hard Tissue Regeneration and Challenges-A Narrative Review. SCIENTIFICA 2024; 2024:9990562. [PMID: 38690100 PMCID: PMC11057954 DOI: 10.1155/2024/9990562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/01/2024] [Accepted: 03/27/2024] [Indexed: 05/02/2024]
Abstract
Background As people live longer, there is an increasing need for hard tissue regeneration and whole-tooth regeneration. Despite the advancements in the field of medicine, the field of regenerative dentistry is still challenging due to the complexity of dental hard tissues. Cross-disciplinary collaboration among material scientists, cellular biologists, and odontologists aimed at developing strategies and uncovering solutions related to dental tissue regeneration. Methodology. A search of the literature was done for pertinent research. Consistent with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020 Statement, the electronic databases looked at were PubMed, Science Direct, Scopus, and Google Scholar, with the keyword search "hard dental tissue regeneration." Results Database analysis yielded a total of 476 articles. 222 duplicate articles have been removed in total. Articles that have no connection to the directed regeneration of hard dental tissue were disregarded. The review concluded with the inclusion of four studies that were relevant to our research objective. Conclusion Current molecular signaling network investigations and novel viewpoints on cellular heterogeneity have made advancements in understanding of the kinetics of dental hard tissue regeneration possible. Here, we outline the fundamentals of stem hard dental tissue maintenance, regeneration, and repair, as well as recent advancements in the field of hard tissue regeneration. These intriguing findings help establish a framework that will eventually enable basic research findings to be utilized towards oral health-improving medicines.
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Affiliation(s)
- Muhsen Alnasser
- Department of Restorative Dental Sciences, College of Dentistry, Jouf University, Sakaka, Saudi Arabia
| | | | - Amna Yusuf Siddiqui
- Department of Endodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Osama Shujaa Alothmani
- Department of Endodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Rakhi Issrani
- Department of Preventive Dentistry, College of Dentistry, Jouf University, Sakaka, Saudi Arabia
- Department of Research Analytics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India
| | - Azhar Iqbal
- Department of Restorative Dental Sciences, College of Dentistry, Jouf University, Sakaka, Saudi Arabia
| | - Osama Khattak
- Department of Restorative Dental Sciences, College of Dentistry, Jouf University, Sakaka, Saudi Arabia
| | - Namdeo Prabhu
- Department of Oral and Maxillofacial Surgery and Diagnostic Sciences, College of Dentistry, Jouf University, Sakaka, Saudi Arabia
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Enamel Matrix Derivatives for Periodontal Regeneration: Recent Developments and Future Perspectives. JOURNAL OF HEALTHCARE ENGINEERING 2022; 2022:8661690. [PMID: 35449833 PMCID: PMC9017460 DOI: 10.1155/2022/8661690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 03/23/2022] [Indexed: 11/18/2022]
Abstract
In the era of the growing population, the demand for dental care is increasing at a fast pace for both older and younger people. One of the dental diseases that has attracted significant research is periodontitis. Periodontal therapy aims to regenerate tissues that are injured by periodontal disease. During recent decades, various pioneering strategies and products have been introduced for restoring or regeneration of periodontal deficiencies. One of these involves the regeneration of tissues under guidance using enamel matrix derivatives (EMDs) or combinations of these. EMDs are mainly comprised of amelogenins, which is one of the most common biological agents used in periodontics. Multiple studies have been reported regarding the role of EMD in periodontal tissue regeneration; however, the extensive mechanism remains elusive. The EMDs could promote periodontal regeneration mainly through inducing periodontal attachment during tooth formation. EMD mimics biological processes that occur during periodontal tissue growth. During root development, enamel matrix proteins are formed on the root surface by Hertwig's epithelial root sheath cells, initiating the process of cementogenesis. This article reviews the challenges and recent advances in preclinical and clinical applications of EMDs in periodontal regeneration. Moreover, we discuss the current evidence on the mechanisms of action of EMDs in the regeneration of periodontal tissues.
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3
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Hubbard MJ, Mangum JE, Perez VA, Williams R. A Breakthrough in Understanding the Pathogenesis of Molar Hypomineralisation: The Mineralisation-Poisoning Model. Front Physiol 2022; 12:802833. [PMID: 34992550 PMCID: PMC8724775 DOI: 10.3389/fphys.2021.802833] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 11/26/2021] [Indexed: 11/13/2022] Open
Abstract
Popularly known as "chalky teeth", molar hypomineralisation (MH) affects over 1-in-5 children worldwide, triggering massive amounts of suffering from toothache and rapid decay. MH stems from childhood illness and so offers a medical-prevention avenue for improving oral and paediatric health. With a cross-sector translational research and education network (The D3 Group; thed3group.org) now highlighting this global health opportunity, aetiological understanding is urgently needed to enable better awareness, management and eventual prevention of MH. Causation and pathogenesis of "chalky enamel spots" (i.e., demarcated opacities, the defining pathology of MH) remain unclear despite 100 years of investigation. However, recent biochemical studies provided a pathomechanistic breakthrough by explaining several hallmarks of chalky opacities for the first time. This article outlines these findings in context of previous understanding and provides a working model for future investigations. The proposed pathomechanism, termed "mineralisation poisoning", involves localised exposure of immature enamel to serum albumin. Albumin binds to enamel-mineral crystals and blocks their growth, leading to chalky opacities with distinct borders. Being centred on extracellular fluid rather than enamel-forming cells as held by dogma, this localising pathomechanism invokes a new type of connection with childhood illness. These advances open a novel direction for research into pathogenesis and causation of MH, and offer prospects for better clinical management. Future research will require wide-ranging inputs that ideally should be coordinated through a worldwide translational network. We hope this breakthrough will ultimately lead to medical prevention of MH, prompting global health benefits including major reductions in childhood tooth decay.
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Affiliation(s)
- Michael J Hubbard
- Faculty of Medicine Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia.,Department of Pharmacology & Therapeutics, The University of Melbourne, Parkville, VIC, Australia.,Melbourne Dental School, The University of Melbourne, Parkville, VIC, Australia
| | - Jonathan E Mangum
- Department of Pharmacology & Therapeutics, The University of Melbourne, Parkville, VIC, Australia
| | - Vidal A Perez
- Department of Pharmacology & Therapeutics, The University of Melbourne, Parkville, VIC, Australia.,Department of Pediatric Stomatology, Faculty of Health Sciences, University of Talca, Talca, Chile
| | - Rebecca Williams
- Department of Pharmacology & Therapeutics, The University of Melbourne, Parkville, VIC, Australia.,Melbourne Dental School, The University of Melbourne, Parkville, VIC, Australia
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4
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Gan L, Liu Y, Cui DX, Pan Y, Wan M. New insight into dental epithelial stem cells: Identification, regulation, and function in tooth homeostasis and repair. World J Stem Cells 2020; 12:1327-1340. [PMID: 33312401 PMCID: PMC7705464 DOI: 10.4252/wjsc.v12.i11.1327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/21/2020] [Accepted: 09/15/2020] [Indexed: 02/06/2023] Open
Abstract
Tooth enamel, a highly mineralized tissue covering the outermost area of teeth, is always damaged by dental caries or trauma. Tooth enamel rarely repairs or renews itself, due to the loss of ameloblasts and dental epithelial stem cells (DESCs) once the tooth erupts. Unlike human teeth, mouse incisors grow continuously due to the presence of DESCs that generate enamel-producing ameloblasts and other supporting dental epithelial lineages. The ready accessibility of mouse DESCs and wide availability of related transgenic mouse lines make mouse incisors an excellent model to examine the identity and heterogeneity of dental epithelial stem/progenitor cells; explore the regulatory mechanisms underlying enamel formation; and help answer the open question regarding the therapeutic development of enamel engineering. In the present review, we update the current understanding about the identification of DESCs in mouse incisors and summarize the regulatory mechanisms of enamel formation driven by DESCs. The roles of DESCs during homeostasis and repair are also discussed, which should improve our knowledge regarding enamel tissue engineering.
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Affiliation(s)
- Lu Gan
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Ying Liu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Di-Xin Cui
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Yue Pan
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Mian Wan
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan Province, China
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5
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Perez VA, Mangum JE, Hubbard MJ. Pathogenesis of Molar Hypomineralisation: Aged Albumin Demarcates Chalky Regions of Hypomineralised Enamel. Front Physiol 2020; 11:579015. [PMID: 33101060 PMCID: PMC7556231 DOI: 10.3389/fphys.2020.579015] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/04/2020] [Indexed: 11/13/2022] Open
Abstract
Molar hypomineralisation (MH) is becoming globally recognised as a significant public health problem linked to childhood tooth decay. However, with causation and pathogenesis unclear after 100 years of investigation, better pathological understanding is needed if MH is to become preventable. Our studies have implicated serum albumin in an extracellular pathomechanism for chalky enamel, opposing longheld dogma about systemic injury to enamel-forming cells. Hypothesising that chalky enamel arises through developmental exposure to serum albumin, this study used biochemical approaches to characterise demarcated opacities from 6-year molars. Addressing contradictory literature, normal enamel was found to completely lack albumin subject to removal of surface contamination. Querying surface permeability, intact opacities were found to lack salivary amylase, indicating that “enamel albumin” had become entrapped before tooth eruption. Thirdly, comparative profiling of chalky and hard-white enamel supported a dose-response relationship between albumin and clinical hardness of opacities. Moreover, albumin abundance delineated chalky enamel from white transitional enamel at opacity borders. Finally, addressing the corollary that enamel albumin had been entrapped for several years, clear signs of molecular ageing (oxidative aggregation and fragmentation) were identified. By establishing aged albumin as a biomarker for chalky enamel, these findings hold methodological, clinical, and aetiological significance. Foremost, direct inhibition of enamel-crystal growth by albumin (here termed “mineralisation poisoning”) at last provides a cogent explanation for the clinical presentation of demarcated opacities. Together, these findings justify pursuit of an extracellular paradigm for the pathogenesis of MH and offer exciting new prospects for alleviating childhood tooth decay through medical prevention of MH.
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Affiliation(s)
- Vidal A Perez
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC, Australia.,Department of Pediatric Stomatology, Faculty of Health Sciences, University of Talca, Talca, Chile
| | - Jonathan E Mangum
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC, Australia
| | - Michael J Hubbard
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia.,Faculty of Medicine Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia.,Melbourne Dental School, The University of Melbourne, Parkville, VIC, Australia
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Gil-Bona A, Bidlack FB. Tooth Enamel and its Dynamic Protein Matrix. Int J Mol Sci 2020; 21:ijms21124458. [PMID: 32585904 PMCID: PMC7352428 DOI: 10.3390/ijms21124458] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 12/12/2022] Open
Abstract
Tooth enamel is the outer covering of tooth crowns, the hardest material in the mammalian body, yet fracture resistant. The extremely high content of 95 wt% calcium phosphate in healthy adult teeth is achieved through mineralization of a proteinaceous matrix that changes in abundance and composition. Enamel-specific proteins and proteases are known to be critical for proper enamel formation. Recent proteomics analyses revealed many other proteins with their roles in enamel formation yet to be unraveled. Although the exact protein composition of healthy tooth enamel is still unknown, it is apparent that compromised enamel deviates in amount and composition of its organic material. Why these differences affect both the mineralization process before tooth eruption and the properties of erupted teeth will become apparent as proteomics protocols are adjusted to the variability between species, tooth size, sample size and ephemeral organic content of forming teeth. This review summarizes the current knowledge and published proteomics data of healthy and diseased tooth enamel, including advancements in forensic applications and disease models in animals. A summary and discussion of the status quo highlights how recent proteomics findings advance our understating of the complexity and temporal changes of extracellular matrix composition during tooth enamel formation.
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Affiliation(s)
- Ana Gil-Bona
- The Forsyth Institute, Cambridge, MA 02142, USA
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
- Correspondence: (A.G.-B.); (F.B.B.)
| | - Felicitas B. Bidlack
- The Forsyth Institute, Cambridge, MA 02142, USA
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
- Correspondence: (A.G.-B.); (F.B.B.)
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7
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Tissue Engineering Approaches for Enamel, Dentin, and Pulp Regeneration: An Update. Stem Cells Int 2020; 2020:5734539. [PMID: 32184832 PMCID: PMC7060883 DOI: 10.1155/2020/5734539] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 01/07/2020] [Indexed: 12/12/2022] Open
Abstract
Stem/progenitor cells are undifferentiated cells characterized by their exclusive ability for self-renewal and multilineage differentiation potential. In recent years, researchers and investigations explored the prospect of employing stem/progenitor cell therapy in regenerative medicine, especially stem/progenitor cells originating from the oral tissues. In this context, the regeneration of the lost dental tissues including enamel, dentin, and the dental pulp are pivotal targets for stem/progenitor cell therapy. The present review elaborates on the different sources of stem/progenitor cells and their potential clinical applications to regenerate enamel, dentin, and the dental pulpal tissues.
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8
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Lepperdinger U, Maurer E, Witsch-Baumgartner M, Stigler R, Zschocke J, Lussi A, Kapferer-Seebacher I. Expanding the phenotype of hypomaturation amelogenesis imperfecta due to a novel SLC24A4 variant. Clin Oral Investig 2020; 24:3519-3525. [PMID: 32034543 DOI: 10.1007/s00784-020-03222-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 01/23/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Biallelic variants in solute carrier family 24 member 4 (SLC24A4) have been previously reported to cause non-syndromic autosomal recessive amelogenesis imperfecta (AI) of the pigmented hypomaturation type (MIM #615887). We here describe a novel variant in SLC24A4 causing mild enamel hypomaturation defects also in heterozygous individuals. MATERIALS AND METHODS In the present pedigree analysis, a large consanguineous Syrian family with AI of the hypomaturation type was investigated by clinical and dental evaluation, and exome and Sanger sequencing. Dental histological investigations of seven primary and two permanent teeth were performed. RESULTS Homozygous variants in SLC24A4 (c.1604G>A; p.Gly535Asp) were identified in five individuals with brown discolorations and irregular pits and grooves of the teeth. Severe attritions, occlusal abfractions, and the radiological lack of contrast between enamel and dentin point out a mineralization defect. Histological dental investigations confirmed the clinical diagnosis of AI of the hypomaturation type. In two heterozygous individuals, a mild hypomaturation defect was present with white and light brown enamel discolorations. CONCLUSIONS This is the first report of heterozygous SLC24A4 variants causing mild hypomaturation defects, providing confirmatory evidence that the function of SLC24A4 in calcium transport has a crucial role in the maturation stage of amelogenesis. CLINICAL RELEVANCE The present report is expanding the clinical phenotype of SLC24A4 variants to more severe forms of amelogenesis imperfecta. An autosomal-dominant inheritance pattern with mild clinical phenotypes in heterozygotes has to be considered.
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Affiliation(s)
- Ulrike Lepperdinger
- Department of Operative and Restorative Dentistry, Medical University of Innsbruck, Anichstraße 35, A-6020, Innsbruck, Austria
| | - Elisabeth Maurer
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | | | - Robert Stigler
- Department of Oral and Maxillofacial Surgery, Medical University Innsbruck, Innsbruck, Austria
| | - Johannes Zschocke
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Adrian Lussi
- Department of Operative Dentistry and Periodontology, Faculty of Dentistry, University Medical Centre, Freiburg, Germany
| | - Ines Kapferer-Seebacher
- Department of Operative and Restorative Dentistry, Medical University of Innsbruck, Anichstraße 35, A-6020, Innsbruck, Austria.
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9
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Pandya M, Diekwisch TGH. Enamel biomimetics-fiction or future of dentistry. Int J Oral Sci 2019. [PMID: 30610185 DOI: 10.1038/s41368-018-0038-6,1-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.
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Affiliation(s)
- Mirali Pandya
- Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, USA
| | - Thomas G H Diekwisch
- Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, USA.
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10
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Abstract
Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues. Five pathways for tooth enamel engineering hold great promise for developing new technologies, leading to novel biomaterials and biotechnologies to regenerate enamel tissue. Tooth enamel is a unique tissue-specific biomaterial with exceptional structural and mechanical properties. In recent years, many approaches have been adopted to generate or regenerate this complex tissue; Mirali Pandya and Thomas Diekwisch of Texas A&M College of Dentistry, USA conducted a review of the current state and future directions of enamel tissue engineering. In their review, the authors focused on five pathways for enamel tissue engineering: (1) physical synthesis of enamel; (2) biochemical enamel engineering; (3) in situ enamel engineering; (4) cell-based enamel engineering; and (5) whole tooth regeneration. The authors conclude that those five approaches will help identify the biological mechanisms that lead to the generation of tooth enamel.
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Perez VA, Mangum JE, Hubbard MJ. Direct evidence that KLK4 is a hydroxyapatite-binding protein. Biochem Biophys Res Commun 2017; 495:1896-1900. [PMID: 29229389 DOI: 10.1016/j.bbrc.2017.12.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 12/07/2017] [Indexed: 11/17/2022]
Abstract
The protease kallikrein 4 (KLK4) plays a pivotal role during dental enamel formation by degrading the major enamel protein, amelogenin, prior to the final steps of enamel hardening. KLK4 dysfunction is known to cause some types of developmental defect in enamel but the mechanisms responsible for transient retention of KLK4 in semi-hardened enamel matrix remain unclear. To address contradictory reports about the affinity of KLK4 for enamel hydroxyapatite-like mineral, we used pure components in quasi-physiological conditions and found that KLK4 binds hydroxyapatite directly. Hypothesising KLK4 self-destructs once amelogenin is degraded, biochemical analyses revealed that KLK4 progressively lost activity, became aggregated, and autofragmented when incubated without substrate in both the presence and absence of reducer. However, with non-ionic detergent present as proxy substrate, KLK4 remained active and intact throughout. These findings prompt a new mechanistic model and line of enquiry into the role of KLK4 in enamel hardening and malformation.
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Affiliation(s)
- Vidal A Perez
- Department of Pharmacology & Therapeutics, The University of Melbourne, Victoria, Australia; Department of Pediatric Stomatology, University of Talca, Talca, Chile
| | - Jonathan E Mangum
- Department of Pharmacology & Therapeutics, The University of Melbourne, Victoria, Australia
| | - Michael J Hubbard
- Department of Pharmacology & Therapeutics, The University of Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia.
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12
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Hubbard MJ, Mangum JE, Perez VA, Nervo GJ, Hall RK. Molar Hypomineralisation: A Call to Arms for Enamel Researchers. Front Physiol 2017; 8:546. [PMID: 28824445 PMCID: PMC5540900 DOI: 10.3389/fphys.2017.00546] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/14/2017] [Indexed: 11/20/2022] Open
Abstract
Developmental dental defects (DDDs, hereafter “D3s”) hold significance for scientists and practitioners from both medicine and dentistry. Although, attention has classically dwelt on three other D3s (amelogenesis imperfecta, dental fluorosis, and enamel hypoplasia), dental interest has recently swung toward Molar Hypomineralisation (MH), a prevalent condition characterised by well-delineated (“demarcated”) opacities in enamel. MH imposes a significant burden on global health and has potential to become medically preventable, being linked to infantile illness. Yet even in medico-dental research communities there is only narrow awareness of this childhood problem and its link to tooth decay, and of allied research opportunities. Major knowledge gaps exist at population, case and tooth levels and salient information from enamel researchers has sometimes been omitted from clinically-oriented conclusions. From our perspective, a cross-sector translational approach is required to address these complex inadequacies effectively, with the ultimate aim of prevention. Drawing on experience with a translational research network spanning Australia and New Zealand (The D3 Group; www.thed3group.org), we firstly depict MH as a silent public health problem that is generally more concerning than the three classical D3s. Second, we argue that diverse research inputs are needed to undertake a multi-faceted attack on this problem, and outline demarcated opacities as the central research target. Third, we suggest that, given past victories studying other dental conditions, enamel researchers stand to make crucial contributions to the understanding and prevention of MH. Finally, to focus geographically diverse research interests onto this nascent field, further internationalisation of The D3 Group is warranted.
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Affiliation(s)
- Michael J Hubbard
- Department of Paediatrics, University of MelbourneMelbourne, VIC, Australia.,Department of Pharmacology and Therapeutics, University of MelbourneMelbourne, VIC, Australia
| | - Jonathan E Mangum
- Department of Pharmacology and Therapeutics, University of MelbourneMelbourne, VIC, Australia
| | - Vidal A Perez
- Department of Pharmacology and Therapeutics, University of MelbourneMelbourne, VIC, Australia.,Department of Pediatric Stomatology, University of TalcaTalca, Chile
| | - Garry J Nervo
- Department of Pharmacology and Therapeutics, University of MelbourneMelbourne, VIC, Australia
| | - Roger K Hall
- Department of Pharmacology and Therapeutics, University of MelbourneMelbourne, VIC, Australia
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