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Montoya C, Kurylec J, Ossa A, Orrego S. Cyclic strain of poly (methyl methacrylate) surfaces triggered the pathogenicity of Candida albicans. Acta Biomater 2023; 170:415-426. [PMID: 37625677 DOI: 10.1016/j.actbio.2023.08.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/21/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023]
Abstract
Candida albicans is an opportunistic yeast and the primary etiological factor in oral candidiasis and denture stomatitis. The pathogenesis of C. albicans could be triggered by several variables, including environmental, nutritional, and biomaterial surface cues. Specifically, biomaterial interactions are driven by different surface properties, including wettability, stiffness, and roughness. Dental biomaterials experience repetitive (cyclic) stresses from chewing and biomechanical movements. Pathogenic biofilms are formed over these biomaterial surfaces under cyclic strain. This study investigated the effect of the cyclic strain (deformation) of biomaterial surfaces on the virulence of Candida albicans. Candida biofilms were grown over Poly (methyl methacrylate) (PMMA) surfaces subjected to static (no strain) and cyclic strain with different levels (ε˜x=0.1 and 0.2%). To evaluate the biomaterial-biofilm interactions, the biofilm characteristics, yeast-to-hyphae transition, and the expression of virulent genes were measured. Results showed the biofilm biomass and metabolic activity to be significantly higher when Candida adhered to surfaces subjected to cyclic strain compared to static surfaces. Examination of the yeast-to-hyphae transition showed pseudo-hyphae cells (pathogenic) in cyclically strained biomaterial surfaces, whereas static surfaces showed spherical yeast cells (commensal). RNA sequencing was used to determine and compare the transcriptome profiles of cyclically strained and static surfaces. Genes and transcription factors associated with cell adhesion (CSH1, PGA10, and RBT5), biofilm formation (EFG1), and secretion of extracellular matrix (ECM) (CRH1, ADH5, GCA1, and GCA2) were significantly upregulated in the cyclically strained biomaterial surfaces compared to static ones. Genes and transcription factors associated with virulence (UME6 and HGC1) and the secretion of extracellular enzymes (LIP, PLB, and SAP families) were also significantly upregulated in the cyclically strained biomaterial surfaces compared to static. For the first time, this study reveals a biomaterial surface factor triggering the pathogenesis of Candida albicans, which is essential for understanding, controlling, and preventing oral infections. STATEMENT OF SIGNIFICANCE: Fungal infections produced by Candida albicans are a significant contributor to various health conditions. Candida becomes pathogenic when certain environmental conditions change, including temperature, pH, nutrients, and CO2 levels. In addition, surface properties, including wettability, stiffness, and roughness, drive the interactions between Candida and biomaterials. Clinically, Candida adheres to biomaterials that are under repetitive deformation due to body movements. In this work, we revealed that when Candida adhered to biomaterial surfaces subjected to repetitive deformation, the microorganism becomes pathogenic by increasing the formation of biofilms and the expression of virulent factors related to hyphae formation and secretion of enzymes. Findings from this work could aid the development of new strategies for treating fungal infections in medical devices or implanted biomaterials.
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Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, United States
| | - Julia Kurylec
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, United States
| | - Alex Ossa
- Production Engineering Department, School of Engineering, Universidad EAFIT, Medellín, Colombia
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, United States; Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, United States.
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Abstract
Despite its reputation as the most widely used restorative dental material currently, resin-based materials have acknowledged shortcomings. As most systematic survival studies of resin composites and dental adhesives indicate, secondary caries is the foremost reason for resin-based restoration failure and life span reduction. In subjects with high caries risk, the microbial community dominated by acidogenic and acid-tolerant bacteria triggers acid-induced deterioration of the bonding interface and/or bulk material and mineral loss around the restorations. In addition, resin-based materials undergo biodegradation in the oral cavity. As a result, the past decades have seen exponential growth in developing restorative dental materials for antimicrobial applications addressing secondary caries prevention and progression. Currently, the main challenge of bioactive resin development is the identification of efficient and safe anticaries agents that are detrimental free to final material properties and show satisfactory long-term performance and favorable clinical translation. This review centers on the continuous efforts to formulate novel bioactive resins employing 1 or multiple agents to enhance the antibiofilm efficacy or achieve multiple functionalities, such as remineralization and antimicrobial activity antidegradation. We present a comprehensive synthesis of the constraints and challenges encountered in the formulation process, the clinical performance-related prerequisites, the materials' intended applicability, and the current advancements in clinical implementation. Moreover, we identify crucial vulnerabilities that arise during the development of dental materials, including particle aggregation, alterations in color, susceptibility to hydrolysis, and loss of physicomechanical core properties of the targeted materials.
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Affiliation(s)
- M.A.S. Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
- Dental Biomedical Sciences PhD Program, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - I.M. Garcia
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - L. Mokeem
- Dental Biomedical Sciences PhD Program, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - M.D. Weir
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - H.H.K. Xu
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - C. Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - S. Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, USA
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Roldan L, Montoya C, Solanki V, Cai KQ, Yang M, Correa S, Orrego S. A Novel Injectable Piezoelectric Hydrogel for Periodontal Disease Treatment. ACS Appl Mater Interfaces 2023; 15:43441-43454. [PMID: 37672788 DOI: 10.1021/acsami.3c08336] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Periodontal disease is a multifactorial, bacterially induced inflammatory condition characterized by the progressive destruction of periodontal tissues. The successful nonsurgical treatment of periodontitis requires multifunctional technologies offering antibacterial therapies and promotion of bone regeneration simultaneously. For the first time, in this study, an injectable piezoelectric hydrogel (PiezoGEL) was developed after combining gelatin methacryloyl (GelMA) with biocompatible piezoelectric fillers of barium titanate (BTO) that produce electrical charges when stimulated by biomechanical vibrations (e.g., mastication, movements). We harnessed the benefits of hydrogels (injectable, light curable, conforms to pocket spaces, biocompatible) with the bioactive effects of piezoelectric charges. A thorough biomaterial characterization confirmed piezoelectric fillers' successful integration with the hydrogel, photopolymerizability, injectability for clinical use, and electrical charge generation to enable bioactive effects (antibacterial and bone tissue regeneration). PiezoGEL showed significant reductions in pathogenic biofilm biomass (∼41%), metabolic activity (∼75%), and the number of viable cells (∼2-3 log) compared to hydrogels without BTO fillers in vitro. Molecular analysis related the antibacterial effects to be associated with reduced cell adhesion (downregulation of porP and fimA) and increased oxidative stress (upregulation of oxyR) genes. Moreover, PiezoGEL significantly enhanced bone marrow stem cell (BMSC) viability and osteogenic differentiation by upregulating RUNX2, COL1A1, and ALP. In vivo, PiezoGEL effectively reduced periodontal inflammation and increased bone tissue regeneration compared to control groups in a mice model. Findings from this study suggest PiezoGEL to be a promising and novel therapeutic candidate for the treatment of periodontal disease nonsurgically.
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Affiliation(s)
- Lina Roldan
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Research Group (GIB), Universidad EAFIT, Medellín 050037, Colombia
| | - Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Varun Solanki
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Kathy Q Cai
- Histopathology Facility, Fox Chase Cancer, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Maobin Yang
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Santiago Correa
- Bioengineering Research Group (GIB), Universidad EAFIT, Medellín 050037, Colombia
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Department, College of Engineering, Temple University. Philadelphia, Pennsylvania 19122, United States
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Roldan L, Isaza C, Ospina J, Montoya C, Domínguez J, Orrego S, Correa S. A Comparative Study of HA/DBM Compounds Derived from Bovine and Porcine for Bone Regeneration. J Funct Biomater 2023; 14:439. [PMID: 37754853 PMCID: PMC10532284 DOI: 10.3390/jfb14090439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 07/25/2023] [Accepted: 08/17/2023] [Indexed: 09/28/2023] Open
Abstract
This comparative study investigated the tissue regeneration and inflammatory response induced by xenografts comprised of hydroxyapatite (HA) and demineralized bone matrix (DBM) extracted from porcine (P) and bovine (B) sources. First, extraction of HA and DBM was independently conducted, followed by chemical and morphological characterization. Second, mixtures of HA/DBM were prepared in 50/50 and 60/40 concentrations, and the chemical, morphological, and mechanical properties were evaluated. A rat calvarial defect model was used to evaluate the tissue regeneration and inflammatory responses at 3 and 6 months. The commercial allograft DBM Puros® was used as a clinical reference. Different variables related to tissue regeneration were evaluated, including tissue thickness regeneration (%), amount of regenerated bone area (%), and amount of regenerated collagen area (%). The inflammatory response was evaluated by quantifying the blood vessel area. Overall, tissue regeneration from porcine grafts was superior to bovine. After 3 months of implantation, the tissue thickness regeneration in the 50/50P compound and the commercial DBM was significantly higher (~99%) than in the bovine materials (~23%). The 50/50P and DBM produced higher tissue regeneration than the naturally healed controls. Similar trends were observed for the regenerated bone and collagen areas. The blood vessel area was correlated with tissue regeneration in the first 3 months of evaluation. After 6 months of implantation, HA/DBM compounds showed less regenerated collagen than the DBM-only xenografts. In addition, all animal-derived xenografts improved tissue regeneration compared with the naturally healed defects. No clinical complications associated with any implanted compound were noted.
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Affiliation(s)
- Lina Roldan
- Grupo de Investigación en Bioingeniería (GIB), Universidad EAFIT, Medellín 050022, Colombia; (L.R.); (C.I.)
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA 19122, USA; (C.M.); (S.O.)
| | - Catalina Isaza
- Grupo de Investigación en Bioingeniería (GIB), Universidad EAFIT, Medellín 050022, Colombia; (L.R.); (C.I.)
| | - Juan Ospina
- Centro de Investigación y Desarrollo Cárnico, Industrias de Alimentos Zenú S.A.S., Grupo Nutresa, Medellín 050044, Colombia;
| | - Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA 19122, USA; (C.M.); (S.O.)
| | - José Domínguez
- Grupo de Investigación en Bioingeniería (GIB), Universidad EAFIT, Medellín 050022, Colombia; (L.R.); (C.I.)
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA 19122, USA; (C.M.); (S.O.)
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA 191122, USA
| | - Santiago Correa
- Grupo de Investigación en Bioingeniería (GIB), Universidad EAFIT, Medellín 050022, Colombia; (L.R.); (C.I.)
- Escuela de Ciencias Aplicadas e Ingeniería, Universidad EAFIT, Medellín 050022, Colombia
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Montoya C, Roldan L, Yu M, Valliani S, Ta C, Yang M, Orrego S. Smart dental materials for antimicrobial applications. Bioact Mater 2023; 24:1-19. [PMID: 36582351 PMCID: PMC9763696 DOI: 10.1016/j.bioactmat.2022.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/17/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
Smart biomaterials can sense and react to physiological or external environmental stimuli (e.g., mechanical, chemical, electrical, or magnetic signals). The last decades have seen exponential growth in the use and development of smart dental biomaterials for antimicrobial applications in dentistry. These biomaterial systems offer improved efficacy and controllable bio-functionalities to prevent infections and extend the longevity of dental devices. This review article presents the current state-of-the-art of design, evaluation, advantages, and limitations of bioactive and stimuli-responsive and autonomous dental materials for antimicrobial applications. First, the importance and classification of smart biomaterials are discussed. Second, the categories of bioresponsive antibacterial dental materials are systematically itemized based on different stimuli, including pH, enzymes, light, magnetic field, and vibrations. For each category, their antimicrobial mechanism, applications, and examples are discussed. Finally, we examined the limitations and obstacles required to develop clinically relevant applications of these appealing technologies.
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Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Lina Roldan
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Research Group (GIB), Universidad EAFIT, Medellín, Colombia
| | - Michelle Yu
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Sara Valliani
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Christina Ta
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Maobin Yang
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, USA
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, USA
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Ghosh S, Qiao W, Yang Z, Orrego S, Neelakantan P. Engineering Dental Tissues Using Biomaterials with Piezoelectric Effect: Current Progress and Future Perspectives. J Funct Biomater 2022; 14:jfb14010008. [PMID: 36662055 PMCID: PMC9867283 DOI: 10.3390/jfb14010008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/08/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Dental caries and traumatic injuries to teeth may cause irreversible inflammation and eventual death of the dental pulp. Nevertheless, predictably, repair and regeneration of the dentin-pulp complex remain a formidable challenge. In recent years, smart multifunctional materials with antimicrobial, anti-inflammatory, and pro-regenerative properties have emerged as promising approaches to meet this critical clinical need. As a unique class of smart materials, piezoelectric materials have an unprecedented advantage over other stimuli-responsive materials due to their inherent capability to generate electric charges, which have been shown to facilitate both antimicrobial action and tissue regeneration. Nonetheless, studies on piezoelectric biomaterials in the repair and regeneration of the dentin-pulp complex remain limited. In this review, we summarize the biomedical applications of piezoelectric biomaterials in dental applications and elucidate the underlying molecular mechanisms contributing to the biological effect of piezoelectricity. Moreover, we highlight how this state-of-the-art can be further exploited in the future for dental tissue engineering.
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Affiliation(s)
- Sumanta Ghosh
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Wei Qiao
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Zhengbao Yang
- Department of Mechanical Engineering & Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
| | - Santiago Orrego
- Oral Health Sciences Department, Kornberg School of Dentistry, Temple University, Philadelphia, PA 19140, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA 19140, USA
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
- Correspondence:
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Abstract
Candida-associated denture stomatitis is a recurring disease affecting up to 67% of denture wearers. Poly(methyl methacrylate) (PMMA) remains the main material employed in the fabrication of dentures due to its desirable physical, mechanical, and aesthetic properties. However, the improvement of its antimicrobial properties remains a challenge. To address this need, we developed PMMA composite filled with piezoelectric nanoparticles of barium titanate (BaTiO3) for therapeutic effects. Candida albicans biofilms were cultivated on the surface of the composites under continuous cyclic mechanical loading to activate the piezoelectric charges and to resemble mastication patterns. The interactions between biofilms and biomaterials were evaluated by measuring the biofilm biomass, metabolic activity, and the number of viable cells. To explore the antifungal mechanisms, changes in the expression of genes encoding adhesins and superoxide dismutase were assessed using reverse transcription-polymerase chain reaction. With the addition of piezoelectric nanoparticles, we observed a significant reduction in the biofilm formation and interference in the yeast-to-hyphae transition compared to the standard PMMA. Moreover, we observed that the cyclic deformation of biomaterial surfaces without antifungal agents produced increased biomass, metabolic activity, and a number of viable cells compared to the static/no-deformed surfaces. Cyclic deformation appears to be a novel mechanobiological signal that enables pathogenicity and virulence of C. albicans cells with increased expression of the yeast-to-hyphae transition genes. The outcome of this study opens new opportunities for the design of antifungal dentures for improved clinical service and reduced need for cleaning methods.
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Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University. Philadelphia, Pennsylvania 19140, United States
| | - Julia Kurylec
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University. Philadelphia, Pennsylvania 19140, United States
| | - Divyashri Baraniya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University. Philadelphia, Pennsylvania 19140, United States
| | - Aparna Tripathi
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University. Philadelphia, Pennsylvania 19140, United States
| | - Sumant Puri
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University. Philadelphia, Pennsylvania 19140, United States
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University. Philadelphia, Pennsylvania 19140, United States.,Bioengineering Department, College of Engineering, Temple University. Philadelphia, Pennsylvania 19122, United States
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Montoya C, Jain A, Londoño JJ, Correa S, Lelkes PI, Melo MA, Orrego S. Multifunctional Dental Composite with Piezoelectric Nanofillers for Combined Antibacterial and Mineralization Effects. ACS Appl Mater Interfaces 2021; 13:43868-43879. [PMID: 34494813 DOI: 10.1021/acsami.1c06331] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
After nearly seven decades of development, dental composite restorations continue to show limited clinical service. The triggering point for restoration failure is the degradation of the bond at the tooth-biomaterial interface from chemical, biological, and mechanical sources. Oral biofilms form at the bonded interfaces, producing enzymes and acids that demineralize hard tissues and damage the composite. Removing bacteria from bonded interfaces and remineralizing marginal gaps will increase restorations' clinical service. To address this need, we propose for the first time the use of piezoelectric nanoparticles of barium titanate (BaTiO3) as a multifunctional bioactive filler in dental resin composites, offering combined antibacterial and (re)mineralization effects. In this work, we developed and characterized the properties of dental piezoelectric resin composites, including the degree of conversion and mechanical and physical properties, for restorative applications. Moreover, we evaluated the antibacterial and mineralization responses of piezoelectric composites in vitro. We observed a significant reduction in biofilm growth (up to 90%) and the formation of thick and dense layers of calcium phosphate minerals in piezoelectric composites compared to control groups. The antibacterial mechanism was also revealed. Additionally, we developed a unique approach evaluating the bond strength of dentin-adhesive-composite interfaces subjected to simultaneous attacks from bacteria and cyclic mechanical loading operating in synergy. Our innovative bioactive multifunctional composite provides an ideal technology for restorative applications using a single filler with combined long-lasting nonrechargeable antibacterial/remineralization effects.
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Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Anubhav Jain
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Juan José Londoño
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Research Group (GIB), Department of Mechanical Engineering, Universidad EAFIT, Medellin 050022, Colombia
| | - Santiago Correa
- Bioengineering Research Group (GIB), Department of Mechanical Engineering, Universidad EAFIT, Medellin 050022, Colombia
| | - Peter I Lelkes
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Mary Anne Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, Maryland 21201, United States
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, United States
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Montoya C, Du Y, Gianforcaro AL, Orrego S, Yang M, Lelkes PI. On the road to smart biomaterials for bone research: definitions, concepts, advances, and outlook. Bone Res 2021; 9:12. [PMID: 33574225 PMCID: PMC7878740 DOI: 10.1038/s41413-020-00131-z] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 11/16/2020] [Accepted: 11/20/2020] [Indexed: 01/31/2023] Open
Abstract
The demand for biomaterials that promote the repair, replacement, or restoration of hard and soft tissues continues to grow as the population ages. Traditionally, smart biomaterials have been thought as those that respond to stimuli. However, the continuous evolution of the field warrants a fresh look at the concept of smartness of biomaterials. This review presents a redefinition of the term "Smart Biomaterial" and discusses recent advances in and applications of smart biomaterials for hard tissue restoration and regeneration. To clarify the use of the term "smart biomaterials", we propose four degrees of smartness according to the level of interaction of the biomaterials with the bio-environment and the biological/cellular responses they elicit, defining these materials as inert, active, responsive, and autonomous. Then, we present an up-to-date survey of applications of smart biomaterials for hard tissues, based on the materials' responses (external and internal stimuli) and their use as immune-modulatory biomaterials. Finally, we discuss the limitations and obstacles to the translation from basic research (bench) to clinical utilization that is required for the development of clinically relevant applications of these technologies.
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Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, 19140, USA
| | - Yu Du
- Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, PA, 19140, USA
- Guangdong Provincial Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Anthony L Gianforcaro
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, 19122, USA
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, 19140, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, 19122, USA
| | - Maobin Yang
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, 19140, USA
- Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, PA, 19140, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, 19122, USA
| | - Peter I Lelkes
- Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, PA, 19140, USA.
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, 19122, USA.
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Yang M, Chaghtai A, Melendez M, Hasson H, Whitaker E, Badi M, Sperrazza L, Godel J, Yesilsoy C, Tellez M, Orrego S, Montoya C, Ismail A. Mitigating saliva aerosol contamination in a dental school clinic. BMC Oral Health 2021; 21:52. [PMID: 33546674 PMCID: PMC7863034 DOI: 10.1186/s12903-021-01417-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/15/2021] [Indexed: 12/17/2022] Open
Abstract
Background Transmission of COVID-19 via salivary aerosol particles generated when using handpieces or ultrasonic scalers is a major concern during the COVID-19 pandemic. The aim of this study was to assess the spread of dental aerosols on patients and dental providers during aerosol-generating dental procedures. Methods This pilot study was conducted with one volunteer. A dental unit used at the dental school for general dental care was the site of the experiment. Before the study, three measurement meters (DustTrak 8534, PTrak 8525 and AeroTrak 9306) were used to measure the ambient distribution of particles in the ambient air surrounding the dental chair. The volunteer wore a bouffant, goggles, and shoe covers and was seated in the dental chair in supine position, and covered with a surgical drape. The dentist and dental assistant donned bouffant, goggles, face shields, N95 masks, surgical gowns and shoe covers. The simulation was conducted by using a high-speed handpiece with a diamond bur operating in the oral cavity for 6 min without touching the teeth. A new set of measurement was obtained while using an ultrasonic scaler to clean all teeth of the volunteer. For both aerosol generating procedures, the aerosol particles were measured with the use of saliva ejector (SE) and high-speed suction (HSS) followed a separate set of measurement with the additional use of an extra oral high-volume suction (HVS) unit that was placed close to the mouth to capture the aerosol in addition to SE and HSS. The distribution of the air particles, including the size and concentration of aerosols, was measured around the patient, dentist, dental assistant, 3 feet above the patient, and the floor. Results Four locations were identified with elevated aerosol levels compared to the baseline, including the chest of the dentist, the chest of patient, the chest of assistant and 3 feet above the patient. The use of additional extra oral high volume suction reduced aerosol to or below the baseline level. Conclusions The increase of the level of aerosol with size less than 10 µm was minimal during dental procedures when using SE and HSS. Use of HVS further reduced aerosol levels below the ambient levels.
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Affiliation(s)
- Maobin Yang
- Department of Endodontology, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA.
| | - Asad Chaghtai
- Environmental Health and Radiation Safety, Temple University Health Sciences Center, Philadelphia, USA
| | - Marc Melendez
- Environmental Health and Radiation Safety, Temple University Health Sciences Center, Philadelphia, USA
| | - Hana Hasson
- Department of Restorative Dentistry, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Eugene Whitaker
- Department of Restorative Dentistry, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Mustafa Badi
- Department of Oral and Maxillofacial Pathology, Medicine and Surgery, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Leona Sperrazza
- Department of Oral and Maxillofacial Pathology, Medicine and Surgery, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Jeffrey Godel
- Department of Orthodontics, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Cemil Yesilsoy
- Department of Endodontology, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Marisol Tellez
- Department of Oral Health Sciences, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Santiago Orrego
- Department of Oral Health Sciences, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Carolina Montoya
- Department of Oral Health Sciences, Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
| | - Amid Ismail
- Maurice H Kornberg School of Dentistry, Temple University, Philadelphia, USA
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11
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Orrego S, Chen Z, Krekora U, Hou D, Jeon SY, Pittman M, Montoya C, Chen Y, Kang SH. Bioinspired Materials with Self-Adaptable Mechanical Properties. Adv Mater 2020; 32:e1906970. [PMID: 32301207 DOI: 10.1002/adma.201906970] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 03/06/2020] [Accepted: 03/15/2020] [Indexed: 06/11/2023]
Abstract
Natural structural materials, such as bone, can autonomously modulate their mechanical properties in response to external loading to prevent failure. These material systems smartly control the addition/removal of material in locations of high/low mechanical stress by utilizing local resources guided by biological signals. On the contrary, synthetic structural materials have unchanging mechanical properties limiting their mechanical performance and service life. Inspired by the mineralization process of bone, a material system that adapts its mechanical properties in response to external mechanical loading is reported. It is found that charges from piezoelectric scaffolds can induce mineralization from surrounding media. It is shown that the material system can adapt to external mechanical loading by inducing mineral deposition in proportion to the magnitude of the stress and the resulting piezoelectric charges. Moreover, the mineralization mechanism allows a simple one-step route for fabricating functionally graded materials by controlling the stress distribution along the scaffold. The findings can pave the way for a new class of self-regenerating materials that reinforce regions of high stress or induce deposition of minerals on the damaged areas from the increase in mechanical stress to prevent/mitigate failure. It is envisioned that the findings can contribute to addressing the current challenges of synthetic materials for load-bearing applications from self-adaptive capabilities.
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Affiliation(s)
- Santiago Orrego
- Department of Oral Health Sciences, Temple University, Philadelphia, PA, 19140, USA
- Bioengineering Department, Temple University, Philadelphia, PA, 19140, USA
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Zhezhi Chen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Urszula Krekora
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Decheng Hou
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Seung-Yeol Jeon
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Matthew Pittman
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Carolina Montoya
- Department of Oral Health Sciences, Temple University, Philadelphia, PA, 19140, USA
| | - Yun Chen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Sung Hoon Kang
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, MD, 21218, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
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12
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Du Y, Montoya C, Orrego S, Wei X, Ling J, Lelkes PI, Yang M. Cover Image, Volume 52, Issue 6. Cell Prolif 2019. [DOI: 10.1111/cpr.12728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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13
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Orrego S, Posada K, Ortiz A, Jaramillo J, Gaviria G. PNS46 ATENCION VIRTUAL EN SALUD: DE LA ESTRATEGIA A LA TACTICA. Value Health Reg Issues 2019. [DOI: 10.1016/j.vhri.2019.08.394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Du Y, Montoya C, Orrego S, Wei X, Ling J, Lelkes PI, Yang M. Topographic cues of a novel bilayered scaffold modulate dental pulp stem cells differentiation by regulating YAP signalling through cytoskeleton adjustments. Cell Prolif 2019; 52:e12676. [PMID: 31424140 PMCID: PMC6869304 DOI: 10.1111/cpr.12676] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 02/06/2023] Open
Abstract
Objectives Topographic cues can modulate morphology and differentiation of mesenchymal stem cells. This study aimed to determine how topographic cues of a novel bilayered poly (lactic‐co‐glycolic acid) (PLGA) scaffold affect osteogenic/odontogenic differentiation of dental pulp stem cells (DPSCs). Methods The surface morphology of the scaffolds was visualized by scanning electron microscope, and the surface roughness was measured by profilometry. DPSCs were cultured on each side of the scaffolds. Cell morphology, expression of Yes‐associated protein (YAP) and osteogenic/odontogenic differentiation were analysed by immunohistochemistry, real‐time polymerase chain reaction, and Alizarin Red S staining. In addition, cytochalasin D (CytoD), an F‐actin disruptor, was used to examine the effects of F‐actin on intracellular YAP localisation. Verteporfin, a YAP transcriptional inhibitor, was used to explore the effects of YAP signalling on osteogenic/odontogenic differentiation of DPSCs. Results The closed side of our scaffold showed smaller pores and less roughness than the open side. On the closed side, DPSCs exhibited enhanced F‐actin stress fibre alignment, larger spreading area, more elongated appearance, predominant nuclear YAP localization and spontaneous osteogenic differentiation. Inhibition of F‐actin alignments was correlated with nuclear YAP exclusion of DPSCs. Verteporfin restricted YAP localisation to the cytoplasm, down‐regulated expression of early osteogenic/odontogenic markers and inhibited mineralization of DPSCs cultures. Conclusions The surface topographic cues changed F‐actin alignment and morphology of DPSCs, which in turn regulated YAP signalling to control osteogenic/odontogenic differentiation.
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Affiliation(s)
- Yu Du
- Guangdong Provincial Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.,Regenerative Health Research Laboratory, Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania
| | - Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.,Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Xi Wei
- Guangdong Provincial Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Junqi Ling
- Guangdong Provincial Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Peter I Lelkes
- Regenerative Health Research Laboratory, Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.,Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Maobin Yang
- Regenerative Health Research Laboratory, Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania.,Department of Bioengineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
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Dagro A, Rajbhandari L, Orrego S, Kang SH, Venkatesan A, Ramesh KT. Quantifying the Local Mechanical Properties of Cells in a Fibrous Three-Dimensional Microenvironment. Biophys J 2019; 117:817-828. [PMID: 31421835 DOI: 10.1016/j.bpj.2019.07.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 06/28/2019] [Accepted: 07/26/2019] [Indexed: 12/27/2022] Open
Abstract
Measurements of the mechanical response of biological cells are critical for understanding injury and disease, for developing diagnostic tools, and for computational models in mechanobiology. Although it is well known that cells are sensitive to the topography of their microenvironment, the current paradigm in mechanical testing of adherent cells is mostly limited to specimens grown on flat two-dimensional substrates. In this study, we introduce a technique in which cellular indentation via optical trapping is performed on cells at a high spatial resolution to obtain their regional mechanical properties while they exist in a more favorable three-dimensional microenvironment. We combine our approach with nonlinear contact mechanics theory to consider the effects of a large deformation. This allows us to probe length scales that are relevant for obtaining overall cell stiffness values. The experimental results herein provide the hyperelastic material properties at both high (∼100 s-1) and low (∼1-10 s-1) strain rates of murine central nervous system glial cells. The limitations due to possible misalignment of the indenter in the three-dimensional space are examined using a computational model.
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Affiliation(s)
- Amy Dagro
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland.
| | | | - Santiago Orrego
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Sung Hoon Kang
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, Maryland
| | - Arun Venkatesan
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland
| | - Kaliat T Ramesh
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, Maryland
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Li J, Orrego S, Pan J, He P, Kang SH. Ultrasensitive, flexible, and low-cost nanoporous piezoresistive composites for tactile pressure sensing. Nanoscale 2019; 11:2779-2786. [PMID: 30672952 DOI: 10.1039/c8nr09959f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Highly sensitive flexible tactile sensors are of continuing interest for various applications including wearable devices, human-machine interface systems, and internet of things. Current technologies for high sensitivity piezoresistive sensors rely on costly materials and/or fabrication methods such as graphene-based and micro-structured composites limiting accessibility and scalability. Here, we report a facile sacrificial casting-etching method to synthesize nanoporous carbon nanotube/polymer composites for ultra-sensitive and low-cost piezoresistive pressure sensors. Our synthesis method overcomes the limitations of the traditional solution-dip-coating method for adhering nanoscale conductive materials to the nanoscale porous surface. Importantly, we show ultra-high sensitivity with a strain gauge factor over 300, which is ∼50 times higher than that of traditional CNT-based piezoresistive sensors and ∼10 times higher than that of most of the graphene-based ones. For practical tactile sensing applications, we demonstrate that the sensors can detect both gentle pressures (1 Pa-1 kPa) and low pressures (1 kPa-25 kPa) with a fraction of the cost. Our nanoporous polymer composite could contribute to expanding the scope of using nanocomposites for applications including subtle locomotion sensing, interactive human-machine interface systems, and internet of things from its easy tunability for sensing diverse range of tactile signals.
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Affiliation(s)
- Jing Li
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
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17
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Orrego S, Melo MA, Lee S, Xu HHK, Arola DD. Fatigue of human dentin by cyclic loading and during oral biofilm challenge. J Biomed Mater Res B Appl Biomater 2016; 105:1978-1985. [DOI: 10.1002/jbm.b.33729] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 05/16/2016] [Accepted: 05/24/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Santiago Orrego
- Department of Mechanical EngineeringUniversity of Maryland Baltimore CountyBaltimore Maryland
| | - Mary Anne Melo
- Department of EndodonticsProsthodontics, and Operative Dentistry, Dental School, University of Maryland BaltimoreBaltimore Maryland
| | - Se‐Han Lee
- Division of Mechanical EngineeringKyungnam UniversityChangwon631‐701 Korea
| | - Hockin H. K. Xu
- Department of EndodonticsProsthodontics, and Operative Dentistry, Dental School, University of Maryland BaltimoreBaltimore Maryland
| | - Dwayne D. Arola
- Department of Materials Science and EngineeringUniversity of WashingtonSeattle Washington, DC
- Department of Restorative DentistrySchool of Dentistry, University of WashingtonSeattle Washington, DC
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Melo MA, Orrego S, Weir MD, Xu HHK, Arola DD. Designing Multiagent Dental Materials for Enhanced Resistance to Biofilm Damage at the Bonded Interface. ACS Appl Mater Interfaces 2016; 8:11779-87. [PMID: 27081913 DOI: 10.1021/acsami.6b01923] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The oral environment is considered to be an asperous environment for restored tooth structure. Recurrent dental caries is a common cause of failure of tooth-colored restorations. Bacterial acids, microleakage, and cyclic stresses can lead to deterioration of the polymeric resin-tooth bonded interface. Research on the incorporation of cutting-edge anticaries agents for the design of new, long-lasting, bioactive resin-based dental materials is demanding and provoking work. Released antibacterial agents such as silver nanoparticles (NAg), nonreleased antibacterial macromolecules (DMAHDM, dimethylaminohexadecyl methacrylate), and released acid neutralizer amorphous calcium phosphate nanoparticles (NACP) have shown potential as individual and dual anticaries approaches. In this study, these agents were synthesized, and a prospective combination was incorporated into all the dental materials required to perform a composite restoration: dental primer, adhesive, and composite. We focused on combining different dental materials loaded with multiagents to improve the durability of the complex dental bonding interface. A combined effect of bacterial acid attack and fatigue on the bonding interface simulated the harsh oral environment. Human saliva-derived oral biofilm was grown on each sample prior to the cyclic loading. The oral biofilm viability during the fatigue performance was monitored by the live-dead assay. Damage of the samples that developed during the test was quantified from the fatigue life distributions. Results indicate that the resultant multiagent dental composite materials were able to reduce the acidic impact of the oral biofilm, thereby improving the strength and resistance to fatigue failure of the dentin-resin bonded interface. In summary, this study shows that dental restorative materials containing multiple therapeutic agents of different chemical characteristics can be beneficial toward improving resistance to mechanical and acidic challenges in oral environments.
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Affiliation(s)
- Mary Anne Melo
- Division of Operative Dentistry, Department of General Dentistry, School of Dentistry, University of Maryland Baltimore , Baltimore, Maryland 21201, United States
| | - Santiago Orrego
- Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University , Baltimore, Maryland 21218, United States
| | - Michael D Weir
- Biomaterials and Tissue Engineering Division, Department of Endodontics, Prosthodontics and Periodontics, School of Dentistry, University of Maryland Baltimore , Baltimore, Maryland 21201, United States
| | - Huakun H K Xu
- Biomaterials and Tissue Engineering Division, Department of Endodontics, Prosthodontics and Periodontics, School of Dentistry, University of Maryland Baltimore , Baltimore, Maryland 21201, United States
| | - Dwayne D Arola
- Department of Materials Science & Engineering, College of Engineering, University of Washington , Seattle, Washington 98195, United States
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Orrego S, Romberg E, Arola D. Synergistic degradation of dentin by cyclic stress and buffer agitation. J Mech Behav Biomed Mater 2015; 44:121-32. [PMID: 25637823 PMCID: PMC4499057 DOI: 10.1016/j.jmbbm.2015.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 11/30/2022]
Abstract
Secondary caries and non-carious lesions develop in regions of stress concentrations and oral fluid movement. The objective of this study was to evaluate the influence of cyclic stress and fluid movement on material loss and subsurface degradation of dentin within an acidic environment. Rectangular specimens of radicular dentin were prepared from caries-free unrestored 3rd molars. Two groups were subjected to cyclic cantilever loading within a lactic acid solution (pH = 5) to achieve compressive stresses on the inner (pulpal) or outer sides of the specimens. Two additional groups were evaluated in the same solution, one subjected to movement only (no stress) and the second held stagnant (control: no stress or movement). Exterior material loss profiles and subsurface degradation were quantified on the two sides of the specimens. Results showed that under cyclic stress material loss was significantly greater (p ≤ 0.0005) on the pulpal side than on the outer side and significantly greater (p ≤ 0.05) under compression than tension. However, movement only caused significantly greater material loss (p ≤ 0.0005) than cyclic stress. Subsurface degradation was greatest at the location of highest stress, but was not influenced by stress state or movement.
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Affiliation(s)
- Santiago Orrego
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Elaine Romberg
- Department of Endodontics, Prosthodontics, and Operative Dentistry, Dental School, University of Maryland, Baltimore, MD, USA
| | - Dwayne Arola
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA; Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA, USA.
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Do D, Orrego S, Majd H, Ryou H, Mutluay MM, Xu HHK, Arola D. Accelerated fatigue of dentin with exposure to lactic acid. Biomaterials 2013; 34:8650-8659. [PMID: 23948166 DOI: 10.1016/j.biomaterials.2013.07.090] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 07/26/2013] [Indexed: 11/19/2022]
Abstract
Composite restorations accumulate more biofilm than other dental materials. This increases the likelihood for the hard tissues supporting a restoration (i.e. dentin and enamel) to be exposed to acidic conditions beyond that resulting from dietary variations. In this investigation the fatigue strength and fatigue crack growth resistance of human coronal dentin were characterized within a lactic acid solution (with pH = 5) and compared to that of controls evaluated in neutral conditions (pH = 7). A comparison of the fatigue life distributions showed that the lactic acid exposure resulted in a significant reduction in the fatigue strength (p ≤ 0.001), and nearly 30% reduction in the apparent endurance limit (from 44 MPa to 32 MPa). The reduction in pH also caused a significant decrease (p ≤ 0.05) in the threshold stress intensity range required for the initiation of cyclic crack growth, and significant increase in the incremental rate of crack extension. Exposure of tooth structure to lactic acid may cause demineralization, but it also increases the likelihood of restored tooth failures via fatigue, and after short time periods.
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Affiliation(s)
- D Do
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD USA
| | - S Orrego
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD USA
| | - H Majd
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD USA
| | - H Ryou
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD USA
| | - M M Mutluay
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD USA
- Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland
| | - Hockin H K Xu
- Department of Endodontics, Prosthodontics, and Operative Dentistry, Dental School, University of Maryland, Baltimore, MD 21201
| | - D Arola
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD USA
- Department of Endodontics, Prosthodontics, and Operative Dentistry, Dental School, University of Maryland, Baltimore, MD 21201
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