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Almejrad L, Almansour A, Bartlett D, Austin R. CAD/CAM leucite-reinforced glass-ceramic for simulation of attrition in human enamel in vitro. Dent Mater 2024; 40:173-178. [PMID: 37951749 DOI: 10.1016/j.dental.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/25/2023] [Accepted: 11/04/2023] [Indexed: 11/14/2023]
Abstract
OBJECTIVE Investigate attrition simulation using CAD/CAM leucite-reinforced glass-ceramic antagonists on occlusal vs. buccal enamel. METHODS Three dental materials with known wear rates (resin-modified glass-ionomer, micro-filled, and fine particle composites) validated the wear simulator (CAD/CAM glass-ceramic antagonists, 200 cycles, 80 N load, deionised water irrigation, 0.7 mm sliding movement). Following this, human molars were sectioned into paired occlusal and buccal polished samples (n = 8/gp). Exposed 1.5 mm Ø enamel areas were subjected to attritional wear with and without pre-immersion in citric acid (5 min, 0.3%, pH 3.8). Profilometry measured step-height enamel wear and surface microhardness at different depths was calculated using Vickers indentation at 0.1 N and 0.5 N loads. RESULTS Dental material wear using the CAD/CAM antagonists showed consistency with previous data: mean (SD) resin-modified glass ionomer material loss of 177.77 (16.89) µm vs. 22.15 (1.30) µm fine particle hybrid composite resin wear vs. 13.63 (1.02) µm micro filled composite resin wear (P < 0.001). The coefficient of variation was less than 10%. Following validation, enamel sample wear was significantly increased when attrition was introduced (P < 0.001) independent of buccal vs. occlusal sample location (P < 0.05). Attrition resulted in occlusal wear of 26.1 ± 4.5 µm vs. buccal 26.3 ± 1.2 µm and attrition/erosion resulted in occlusal wear of 26.05 ± 4.46 µm vs. buccal 25.27 ± 1.16 µm. Whereas erosion-alone resulted in occlusal wear of 1.65 ± 0.13 µm and buccal 1.75 ± 0.03 µm. Microhardness testing at different loads revealed significantly greater hardness reductions in occlusal enamel vs. buccal enamel for 0.1 KgF indentations (P < 0.001) whereas in contrast 0.5 KgF indentations showed no differences. SIGNIFICANCE Wear simulation with CAD/CAM glass ceramic antagonists produced consistent wear in dental materials and human enamel, regardless of enamel surface origin. Lighter (0.1 KgF) hardness testing of occlusal vs. buccal origin revealed damage to the mechanical integrity of the superficial worn enamel.
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Affiliation(s)
- Lamya Almejrad
- Department of Prosthodontics, Centre for Oral, Clinical & Translational Sciences, King's College London, Faculty of Dentistry, Oral and Craniofacial Sciences, Guy's Hospital, London SE1 9RT, UK; King Saud University, Collage of Dentistry, Prosthetic Dental Science Department, Riyadh, Saudi Arabia
| | - Abdullah Almansour
- Department of Prosthodontics, Centre for Oral, Clinical & Translational Sciences, King's College London, Faculty of Dentistry, Oral and Craniofacial Sciences, Guy's Hospital, London SE1 9RT, UK; King Sattam Bin Abdulaziz University, College of Dentistry, Al-Kharj, Saudi Arabia
| | - David Bartlett
- Department of Prosthodontics, Centre for Oral, Clinical & Translational Sciences, King's College London, Faculty of Dentistry, Oral and Craniofacial Sciences, Guy's Hospital, London SE1 9RT, UK
| | - Rupert Austin
- Department of Prosthodontics, Centre for Oral, Clinical & Translational Sciences, King's College London, Faculty of Dentistry, Oral and Craniofacial Sciences, Guy's Hospital, London SE1 9RT, UK.
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Ahlawat S, Kanaujia BK, Rambabu K, Peter I, Matekovits L. Circularly polarized differential intra-oral antenna design validation and characterization for tongue drive system. Sci Rep 2023; 13:9935. [PMID: 37336931 DOI: 10.1038/s41598-023-36717-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/08/2023] [Indexed: 06/21/2023] Open
Abstract
Assistive devices are becoming increasingly popular for physically disabled persons suffering tetraplegia and spinal cord injuries. Intraoral tongue drive system (iTDS) is one of the most feasible and non-invasive assistive technology (AT), which utilises the transferring and inferring of user intentions through different tongue gestures. Wireless transferring is of prime importance and requires a suitable design of the intra-oral antenna. In this paper, a compact circularly polarized differential intra-oral antenna is designed, and its performance is analysed within heterogeneous multilayer mouth and head models. It works at 2.4 GHz in the Industrial, Scientific, and Medical (ISM) band. The footprint of the differential antenna prototype is 0.271 λg [Formula: see text] 0.271 λg [Formula: see text] 0.015 λg. It is achieved using two pairs of spiral segments loaded in diagonal form near the edges of the central rotated square slot and a high dielectric constant substrate. Its spiral-slotted geometry further provides the desired swirling and miniaturization at the desired frequency band for both mouth scenarios. Additionally, corner triangular slits on the radiating patch assist in tuning the axial ratio (< 3 dB) in the desired ISM band. To validate the performance of the proposed in-mouth antenna, the measurement was carried out using the minced pork and the saline solution for closed and opened mouth cases, respectively. The measured - 10 dB impedance bandwidth and peak gain values in the minced pork are from 2.28 to 2.53 GHz (10.39%) and - 18.17 dBi, respectively, and in the saline solution, are from 2.3 to 2.54 GHz (9.92%) and - 15.47 dBi, respectively. Further, the specific absorption rate (SAR) is estimated, and the data communication link is computed with and without a balun loss. This confirms that the proposed differential intraoral antenna can establish direct interfacing at the RF front end of the intraoral tongue drive system.
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Affiliation(s)
- Sarita Ahlawat
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Binod Kumar Kanaujia
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
- Dr. Ambedkar National Institute of Technology, Jalandhar, 144011, India
| | - Karumudi Rambabu
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
| | - Ildiko Peter
- Department of Industrial Engineering and Management, Faculty of Engineering and Information Technology, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, 540139, Târgu-Mureş, Romania.
| | - Ladislau Matekovits
- Department of Electronics and Telecommunications, Politecnico di Torino, 10129, Turin, Italy
- Department of Measurements and Optical Electronics, Politehnica University Timisoara, 300223, Timisoara, Romania
- Instituto di Elettronica e di Ingegneria dell'informazione e delle Telecomunicazioni, National Research Council of Italy, 10129, Turin, Italy
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Mansouri M, O'Brien EP, Mondal K, Chen CC, Drummond JL, Hanley L, Rockne KJ. Stoichiometric models of sucrose and glucose fermentation by oral streptococci: Implications for free acid formation and enamel demineralization. Dent Mater 2023; 39:351-361. [PMID: 36906504 PMCID: PMC10162441 DOI: 10.1016/j.dental.2023.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 03/01/2023] [Indexed: 03/12/2023]
Abstract
OBJECTIVES The objective of this study is to develop stoichiometric models of sugar fermentation and cell biosynthesis for model cariogenic Streptococcus mutans and non-cariogenic Streptococcus sanguinis to better understand and predict metabolic product formation. METHODS Streptococcus mutans (strain UA159) and Streptococcus sanguinis (strain DSS-10) were grown separately in bioreactors fed brain heart infusion broth supplemented with either sucrose or glucose at 37 °C. Cell mass concentration and fermentation products were measured at different hydraulic residence times (HRT) to determine cell growth yield. RESULTS Sucrose growth yields were 0.080 ± 0.0078 g cell/g and 0.18 ± 0.031 g cell/g for S. sanguinis and S. mutans, respectively. For glucose, this reversed, with S. sanguinis having a yield of 0.10 ± 0.0080 g cell/g and S. mutans 0.053 ± 0.0064 g cell/g. Stoichiometric equations to predict free acid concentrations were developed for each test case. Results demonstrate that S. sanguinis produces more free acid at a given pH than S. mutans due to lesser cell yield and production of more acetic acid. Greater amounts of free acid were produced at the shortest HRT of 2.5 hr compared to longer HRTs for both microorganisms and substrates. SIGNIFICANCE The finding that the non-cariogenic S. sanguinis produces greater amounts of free acids than S. mutans strongly suggests that bacterial physiology and environmental factors affecting substrate/metabolite mass transfer play a much greater role in tooth or enamel/dentin demineralization than acidogenesis. These findings enhance the understanding of fermentation production by oral streptococci and provide useful data for comparing studies under different environmental conditions.
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Affiliation(s)
- Marzieh Mansouri
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, Chicago, IL, USA
| | - Evan P O'Brien
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, Chicago, IL, USA
| | - Karabi Mondal
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, Chicago, IL, USA
| | - Chien-Chia Chen
- Department of Chemistry, University of Illinois Chicago, Chicago, IL, USA
| | - James L Drummond
- Professor Emeritus of Restorative Dentistry, University of Illinois Chicago, Chicago, IL, USA
| | - Luke Hanley
- Department of Chemistry, University of Illinois Chicago, Chicago, IL, USA
| | - Karl J Rockne
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, Chicago, IL, USA.
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Kruzic JJ, Hoffman M, Arsecularatne JA. Fatigue and wear of human tooth enamel: A review. J Mech Behav Biomed Mater 2023; 138:105574. [PMID: 36473402 DOI: 10.1016/j.jmbbm.2022.105574] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/14/2022] [Accepted: 11/15/2022] [Indexed: 11/21/2022]
Abstract
Human tooth enamel must withstand the cyclic contact forces, wear, and corrosion processes involved with typical oral functions. Furthermore, unlike other human tissues, dental enamel does not have a significant capacity for healing or self-repair and thus the longevity of natural teeth in the oral environment depends to a large degree on the fatigue and wear properties of enamel. The purpose of this review is to provide an overview of our understanding of the fatigue and wear mechanisms of human enamel and how they relate to in vivo observations of tooth damage in the complex oral environment. A key finding of this review is that fatigue and wear processes are closely related. For example, the presence of abrasive wear particles significantly lowers the forces needed to initiate contact fatigue cracking while subsurface fatigue crack propagation drives key delamination wear mechanisms during attrition or attrition-corrosion of enamel. Furthermore, this review seeks to bring a materials science and mechanical engineering perspective to fatigue and wear phenomena. In this regard, we see developing a mechanistic description of fatigue and wear, and understanding the interconnectivity of the processes, as essential for successfully modelling enamel fatigue and wear damage and developing strategies and treatments to improve the longevity of our natural teeth. Furthermore, we anticipate that this review will stimulate ideas for extending the lifetime of the natural tooth structure and will help highlight where our understanding is too limited and where additional research into fatigue and wear of human tooth enamel is warranted.
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Affiliation(s)
- Jamie J Kruzic
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney NSW 2052, Australia.
| | - Mark Hoffman
- School of Engineering, University of Newcastle, Callaghan NSW 2308, Australia; School of Materials Science and Engineering, University of New South Wales (UNSW Sydney), Sydney NSW 2052, Australia
| | - Joseph A Arsecularatne
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney NSW 2052, Australia
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Guo J, Bing Z, Yang J, Tsoi JKH, Wang Y. Effect of roughness and acidic medium on wear behavior of dental resin composite. BMC Oral Health 2022; 22:470. [DOI: 10.1186/s12903-022-02516-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
Abstract
Abstract
Background
The aim of the study was to investigate whether the citric acid and rough surface have a synergistic effect leading to severe wear behavior of resin composite.
Materials and methods
Disk-shaped (Ø15 × 1.5 mm) specimens of resin composite (n = 12) with different initial roughness were prepared. Reciprocating ball-on-flat wear tests were performed under distilled water and citric acid (pH = 5.5) respectively. The coefficient of friction (COF), wear volume loss, and duration of the running-in period were quantified to assess the wear performance. And the values were analyzed with one-way ANOVA (α = 0.05). Regression analysis was applied to examine the influence of Ra values and mediums on the wear data. The wear morphology was analyzed by scanning electron microscopy and a 3D profilometer.
Results
The average COF was higher in distilled water than in citric acid but was independent of the surface roughness. For the composite, the volume loss of worn area and running-in period increased with surface roughness when tested under distilled water. However, these increasing trends were not found in citric acid. All specimens exhibited mild wear behavior with low COF and less superficial abrasion in acidic medium.
Conclusions
The effect of initial roughness on wear behavior depends on the medium. In distilled water, resin composites with high initial roughness exhibit a longer running-in time, which eventually leads to a significant increase in material loss. The adverse effects of high roughness can be alleviated by the lubrication of citric acid, which can maintain a mild wear behavior regardless of initial surface roughness.
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House KL, Pan L, O'Carroll DM, Xu S. Applications of scanning electron microscopy and focused ion beam milling in dental research. Eur J Oral Sci 2022; 130:e12853. [PMID: 35288994 DOI: 10.1111/eos.12853] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 01/06/2022] [Indexed: 12/15/2022]
Abstract
The abilities of scanning electron microscopy (SEM) and focused ion beam (FIB) milling for obtaining high-resolution images from top surfaces, cross-sectional surfaces, and even in three dimensions, are becoming increasingly important for imaging and analyzing tooth structures such as enamel and dentin. FIB was originally developed for material research in the semiconductor industry. However, use of SEM/FIB has been growing recently in dental research due to the versatility of dual platform instruments that can be used as a milling device to obtain low-artifact cross-sections of samples combined with high-resolution images. The advent of the SEM/FIB system and accessories may offer access to previously inaccessible length scales for characterizing tooth structures for dental research, opening exciting opportunities to address many central questions in dental research. New discoveries and fundamental breakthroughs in understanding are likely to follow. This review covers the applications, key findings, and future direction of SEM/FIB in dental research in morphology imaging, specimen preparation for transmission electron microscopy (TEM) analysis, and three-dimensional volume imaging using SEM/FIB tomography.
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Affiliation(s)
- Krystal L House
- Colgate Palmolive Company, Piscataway, New Jersey, USA.,Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Long Pan
- Colgate Palmolive Company, Piscataway, New Jersey, USA
| | - Deirdre M O'Carroll
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA.,Department of Materials Science and Engineering, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Shiyou Xu
- Colgate Palmolive Company, Piscataway, New Jersey, USA
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Fischer NG, Aparicio C. The salivary pellicle on dental biomaterials. Colloids Surf B Biointerfaces 2021; 200:111570. [PMID: 33460965 PMCID: PMC8005451 DOI: 10.1016/j.colsurfb.2021.111570] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/23/2020] [Accepted: 01/07/2021] [Indexed: 12/18/2022]
Abstract
The salivary pellicle, an adlayer formed by adsorption of salivary components on teeth and dental biomaterials, has direct consequences on basic outcomes of dentistry. Here, we provide an overview of salivary pellicle formation processes with a critical focus on dental biomaterials. We describe and critique the array of salivary pellicle measurement techniques. We also discuss factors that may affect salivary pellicle formation and the heterogeneity of the published literature describing salivary pellicle formation on dental biomaterials. Finally, we survey the many effects salivary pellicles have on dental biomaterials and highlight its implications on design criteria for dental biomaterials. Future investigations may lead to rationally designed dental biomaterials to control the salivary pellicle and enhance material function and patient outcomes.
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Affiliation(s)
- Nicholas G Fischer
- MDRCBB, Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Conrado Aparicio
- MDRCBB, Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, Minneapolis, Minnesota, 55455, USA.
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Almeida LKY, Carvalho TS, Bussaneli DG, Jeremias F. Congenital and acquired defects in enamel of primary teeth: prevalence, severity and risk factors in Brazilian children. Eur Arch Paediatr Dent 2021; 22:715-723. [PMID: 33710526 DOI: 10.1007/s40368-021-00612-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 02/27/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE This cross-sectional study evaluated the prevalence of tooth enamel defects and risk factors associated in primary dentition. METHODS A sample of 656 schoolchildren (population based), aged 4 years old, from Araraquara-SP (Brazil) was evaluated by two trained examiners according to the following indexes: Dental fluorosis (DF), deciduous molar hypomineralization (DMH), non-fluoride related developmental defects of enamel (DDE), tooth erosion and tooth attrition. Structured questionnaires identified socioeconomic condition, medical/dental history, behavior and dietary habits. Data were analyzed using Chi-square tests (p < 0.05). RESULTS Of the enamel congenital defects, DF was the most prevalent (6.1%, n = 40), followed by DMH (5.6%, n = 37). Of the acquired defects, attrition was the most prevalent (36.9%, n = 242), followed by erosion (2.4%, n = 16). The caries experience was similar between the affected children (29,5%; n = 94) and total sample (30.6%; n = 201). The etiological factors related to congenital defects were: not exclusively fed breast milk (p = 0.003) and jaundice at birth (p < 0.001); the association with acquired defects was found with vomiting frequent episodes (p = 0.037). CONCLUSION The general prevalence of enamel defects in primary dentition in Araraquara was 48.6%. Enamel defects may be associated with health-related factors and current lifestyle.
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Affiliation(s)
- L K Y Almeida
- Department of Morphology, Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, UNESP, São Paulo State University, Rua Humaitá, 1680, Araraquara, SP, 14801-903, Brasil
| | - T S Carvalho
- Department of Morphology, Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, UNESP, São Paulo State University, Rua Humaitá, 1680, Araraquara, SP, 14801-903, Brasil
| | - D G Bussaneli
- Department of Morphology, Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, UNESP, São Paulo State University, Rua Humaitá, 1680, Araraquara, SP, 14801-903, Brasil
| | - F Jeremias
- Department of Morphology, Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, UNESP, São Paulo State University, Rua Humaitá, 1680, Araraquara, SP, 14801-903, Brasil.
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Branco AC, Colaço R, Figueiredo-Pina CG, Serro AP. A State-of-the-Art Review on the Wear of the Occlusal Surfaces of Natural Teeth and Prosthetic Crowns. MATERIALS 2020; 13:ma13163525. [PMID: 32785120 PMCID: PMC7476047 DOI: 10.3390/ma13163525] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/31/2020] [Accepted: 08/06/2020] [Indexed: 11/16/2022]
Abstract
This review focuses on the wear mechanisms of natural and restorative dental materials, presenting a comprehensive description and analysis of the works published in the last two decades on the wear at the interface of occlusal surfaces. Different groups of tribological pairs were considered: tooth-tooth, tooth-restorative material (tooth-ceramic, tooth-resin-based-materials, and tooth-metal), and restorative-restorative materials. The lack of standardization of the wear tests impairs the direct comparison of the obtained results. However, it was possible to infer about the main wear mechanisms observed on the different classes of dental materials. Concerning ceramics, their toughness and surface finishing determines the wear of antagonist tooth. Abrasion revealed to be the main wear mechanisms at occlusal interface. In the case of resin-based composites, the cohesion of the organic matrix and the nature, shape, and amount of filler particles greatly influences the dental wear. The protruding and detachment of the filler particles are the main causes of abrasion of antagonist enamel. Metallic materials induce lower wear on antagonist enamel than the other classes of materials, because of their low hardness and high ductility. Most of the studies revealed plastic deformation and adhesive wear as the main wear mechanisms. Overall, more research in this area is needed for a better understanding of the mechanisms involved at the occlusal surfaces wear. This would be essential for the development of more suitable restoration materials.
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Affiliation(s)
- Ana Catarina Branco
- Centro de Química Estrutural (CQE), Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (A.C.B.); (A.P.S.)
- Centro de Desenvolvimento de Produto e Transferência de Tecnologia (CDP2T), Department of Mechanical Engineering, Instituto Politécnico de Setúbal, 2910-761 Setúbal, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, 2829-511 Caparica, Portugal
| | - Rogério Colaço
- Instituto de Engenharia Mecânica (IDMEC), Department of Mechanical Engineering, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal;
| | - Célio Gabriel Figueiredo-Pina
- Centro de Desenvolvimento de Produto e Transferência de Tecnologia (CDP2T), Department of Mechanical Engineering, Instituto Politécnico de Setúbal, 2910-761 Setúbal, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, 2829-511 Caparica, Portugal
- Centro de Física e Engenharia de Materiais Avançados (CeFEMA), Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal
- Correspondence:
| | - Ana Paula Serro
- Centro de Química Estrutural (CQE), Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (A.C.B.); (A.P.S.)
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz, 2829-511 Caparica, Portugal
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Abstract
Since 1966 the term “tribology” has integrated different topics like friction, lubrication and wear. After a few years, interest in this type of phenomena rapidly spread out around the world of biology and medicine, determining a new research area defined as biotribology. This commentary is conceived within this framework with the aim of underlining the close link between tribology and dentistry regarding both physiological and restorative issues. The contact between teeth requires investigation into their tribological behavior focusing on the enamel wear process against natural teeth and/or artificial teeth, allowing us to obtain useful information on the tribological behavior of restorative materials. Thus, tested materials may be natural teeth, restorative materials (metal alloys, ceramics, composites) or both. This work aims to make a contribution to underlining the need for greater standardization of tribological experimental procedures as well as to obtaining more homogeneous and indicative results on the tested tribo systems.
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Effect of occlusal slope related to uneven attrition on root stress distribution and potential fracture. J Dent Sci 2019; 13:367-373. [PMID: 30895147 PMCID: PMC6388864 DOI: 10.1016/j.jds.2018.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/19/2018] [Indexed: 11/25/2022] Open
Abstract
Background/purpose Severely uneven occlusal attrition is thought to play an important role in the occurrence of spontaneous vertical root fracture (VRF), a frequent problem among Chinese people. This study evaluated the influence of occlusal slope related to uneven attrition on the root stress condition. Materials and methods A finite element model of the mandibular first molar was established. Two different occlusal slope patterns were simulated in 5 models: (A) sound tooth, (B) 0.5–1.5 mm and (C) 2–3 mm attrition increased buccally, and (D) 0.5–1.5 mm and (E) 2–3 mm attrition increased distally. A static load of 200 N was applied vertically or angled at 45° to the longitudinal axis. The von Mises stress was evaluated. Results Under vertical loading, more stress was transferred from the cervical to the middle root with attrition, especially the mesial root, while stress declined with attrition under oblique loading. Stress was mainly distributed in the buccal surface and mesial root with vertical loading, or in the lingual surface and distal root with oblique loading. The maximum von Mises with oblique loading was significantly higher than with vertical loading. Conclusion Uneven occlusal attrition made the middle of the mesial root bear more stress, increasing fracture risk under vertical load. This finding suggests that timely restoration of the sloped occlusal morphology in teeth with severe attrition should be recommended to prevent VRFs. Lateral loading was not a risk factor of typical vertical root fractures, but the high stress could cause distal root cervical fracture.
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Experimental Comparison on Dental BioTribological Pairs Zirconia/Zirconia and Zirconia/Natural Tooth by Using a Reciprocating Tribometer. J Med Syst 2019; 43:97. [PMID: 30868440 DOI: 10.1007/s10916-019-1230-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/27/2019] [Indexed: 10/27/2022]
Abstract
The application of tribology in dentistry is growing rapidly, intense research has been conducted to develop an understanding of dental tribology for better selection of artificial materials and dental implant design. Dental biotribology, has been one of the most important branches in biotribology in recent years. The aim of this research is to investigate the tribological performances in the tooth-to-tooth contact and material-to-natural tooth contact (zirconia vs. zirconia and natural tooth vs. zirconia). The presented research was carried out by testing the above mentioned tribological pairs with the use of a reciprocating tribometer under lubricated conditions (artificial saliva). The normal force used in the tests was 20 N the time for each test was of 60 min. The stroke length was 2 mm, according to the range of displacement used in scientific literature. The wear mass loss evaluation was evaluated by using a gravimetric method. In order to characterize the wear mechanisms, present in the worn surfaces after each of tribo-tests, a topographic analysis was carried with a 3D non-contact optical profiler. The results show that the minimum value of the COF is obtained in the case of Zirconia vs. Zirconia tribo-couple. The results on the wear mass loss show a very low wear rate when coupling in tribological condition natural tooth with a ceramic restoration (a mean value of 0.5 mg was found). This rate is even lower when the contact is between two artificial zirconia teeth.
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Cougot N, Douillard T, Dalmas F, Pradelle N, Gauthier R, Sanon C, Grosgogeat B, Colon P, Chevalier J. Towards quantitative analysis of enamel erosion by focused ion beam tomography. Dent Mater 2018; 34:e289-e300. [DOI: 10.1016/j.dental.2018.08.304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/30/2018] [Accepted: 08/27/2018] [Indexed: 10/28/2022]
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Kruzic JJ, Arsecularatne JA, Tanaka CB, Hoffman MJ, Cesar PF. Recent advances in understanding the fatigue and wear behavior of dental composites and ceramics. J Mech Behav Biomed Mater 2018; 88:504-533. [PMID: 30223214 DOI: 10.1016/j.jmbbm.2018.08.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/06/2018] [Accepted: 08/08/2018] [Indexed: 12/30/2022]
Abstract
Dental composite and ceramic restorative materials are designed to closely mimic the aesthetics and function of natural tooth tissue, and their longevity in the oral environment depends to a large degree on their fatigue and wear properties. The purpose of this review is to highlight some recent advances in our understanding of fatigue and wear mechanisms, and how they contribute to restoration failures in the complex oral environment. Overall, fatigue and wear processes are found to be closely related, with wear of dental ceramic occlusal surfaces providing initiation sites for fatigue failures, and subsurface fatigue crack propagation driving key wear mechanisms for composites, ceramics, and enamel. Furthermore, both fatigue and wear of composite restorations may be important in enabling secondary caries formation, which is the leading cause of composite restoration failures. Overall, developing a mechanistic description of fatigue, wear, and secondary caries formation, along with understanding the interconnectivity of all three processes, are together seen as essential keys to successfully using in vitro studies to predict in vivo outcomes and develop improved dental restorative materials.
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Affiliation(s)
- Jamie J Kruzic
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, NSW 2052, Australia.
| | | | - Carina B Tanaka
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Mark J Hoffman
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, NSW 2052, Australia; School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Paulo F Cesar
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
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Chowdhury CR, Shahnawaz K, Kumari P D, Chowdhury A, Gootveld M, Lynch E. Highly acidic pH values of carbonated sweet drinks, fruit juices, mineral waters and unregulated fluoride levels in oral care products and drinks in India: a public health concern. Perspect Public Health 2018; 139:186-194. [PMID: 30015577 DOI: 10.1177/1757913918787218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The objective of this study was to quantify and assess the concentrations of fluoride in commonly used oral care products, fruit juices, bottled waters, soft drinks, favoured bottled milk and milkshakes and to determine the pH of carbonated sweet drinks and drinks marketed in India. MATERIALS AND METHODS Various commercial brands of dentifrices, toothpowders, mouthwashes, bottled waters, sweet carbonated drinks and fruit juices were collected randomly from different outlets in Mangalore city, Karnataka, India. A fluoride ion-selective electrode was employed to estimate the fluoride concentrations. A standardised pH meter was used to detect pH in the drinks. RESULTS The fluoride level in toothpastes ranged between 96 and 1397 mg/l, whereas in toothpowder the fluoride content ranged from 35 to 1380 mg/l and mouthwash fluoride concentrations varied from 6 to 228 mg/l. The fluoride level in bottled waters ranged between 0.10 and 0.12 mg/l, and that in fruit juices between 0.09 and 0.21 mg/l. Most of the carbonated sweet drinks and fruit juices had highly acidic pH values which ranged between 2.62 and 4.26. CONCLUSION Of the wide variety of dentifrices and toothpowders available in India, most brands do not indicate the fluoride levels on their packaging or inserts. Similarly, the unregulated acidic pH values of carbonated sweet drinks are not only potentially contributing to non-carious tooth loss (enamel erosion and dentine erosion), but are also a contributing factor to the weight gain observed in Indian adolescents.
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Affiliation(s)
- C R Chowdhury
- Professor Head, Department of Oral Biology & Genomic Studies, A.B. Shetty Memorial Institute of Dental Sciences, Nitte, Deralakatte, Mangalore 575018, India
| | - K Shahnawaz
- Lecturer, Department of Oral Biology & Genomic Studies, A.B. Shetty Memorial Institute of Dental Sciences, Nitte, Mangalore, India
| | - D Kumari P
- Research Scholar, Department of Oral Biology & Genomic Studies, A.B. Shetty Memorial Institute of Dental Sciences, Nitte, Mangalore, India
| | - A Chowdhury
- Researcher, Global Child Dental Health Taskforce, King's College London, London, UK
| | - M Gootveld
- Professor, Faculty of Health and Life Sciences, De Montfort University, Leicester, UK
| | - E Lynch
- Principal Director of Biomedical and Clinical Research, School of Dental Medicine, State University of Nevada UNLV, Las Vegas, Nevada, USA
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Yu P, Xu Z, Arola DD, Min J, Zhao P, Gao S. Effect of acidic agents on the wear behavior of a polymer infiltrated ceramic network (PICN) material. J Mech Behav Biomed Mater 2017; 74:154-163. [DOI: 10.1016/j.jmbbm.2017.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/30/2017] [Accepted: 06/01/2017] [Indexed: 10/19/2022]
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Ranjitkar S, Turan A, Mann C, Gully GA, Marsman M, Edwards S, Kaidonis JA, Hall C, Lekkas D, Wetselaar P, Brook AH, Lobbezoo F, Townsend GC. Surface-Sensitive Microwear Texture Analysis of Attrition and Erosion. J Dent Res 2016; 96:300-307. [PMID: 27927887 DOI: 10.1177/0022034516680585] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Scale-sensitive fractal analysis of high-resolution 3-dimensional surface reconstructions of wear patterns has advanced our knowledge in evolutionary biology, and has opened up opportunities for translatory applications in clinical practice. To elucidate the microwear characteristics of attrition and erosion in worn natural teeth, we scanned 50 extracted human teeth using a confocal profiler at a high optical resolution (X-Y, 0.17 µm; Z < 3 nm). Our hypothesis was that microwear complexity would be greater in erosion and that anisotropy would be greater in attrition. The teeth were divided into 4 groups, including 2 wear types (attrition and erosion) and 2 locations (anterior and posterior teeth; n = 12 for each anterior group, n = 13 for each posterior group) for 2 tissue types (enamel and dentine). The raw 3-dimensional data cloud was subjected to a newly developed rigorous standardization technique to reduce interscanner variability as well as to filter anomalous scanning data. Linear mixed effects (regression) analyses conducted separately for the dependent variables, complexity and anisotropy, showed the following effects of the independent variables: significant interactions between wear type and tissue type ( P = 0.0157 and P = 0.0003, respectively) and significant effects of location ( P < 0.0001 and P = 0.0035, respectively). There were significant associations between complexity and anisotropy when the dependent variable was either complexity ( P = 0.0003) or anisotropy ( P = 0.0014). Our findings of greater complexity in erosion and greater anisotropy in attrition confirm our hypothesis. The greatest geometric means were noted in dentine erosion for complexity and dentine attrition for anisotropy. Dentine also exhibited microwear characteristics that were more consistent with wear types than enamel. Overall, our findings could complement macrowear assessment in dental clinical practice and research and could assist in the early detection and management of pathologic tooth wear.
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Affiliation(s)
- S Ranjitkar
- 1 School of Dentistry, University of Adelaide, Adelaide, Australia
| | - A Turan
- 2 Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute Amsterdam, VU University Amsterdam, Amsterdam, Netherlands
| | - C Mann
- 1 School of Dentistry, University of Adelaide, Adelaide, Australia
| | - G A Gully
- 3 School of Biological Sciences, Flinders University, Bedford Park, Australia
| | - M Marsman
- 2 Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute Amsterdam, VU University Amsterdam, Amsterdam, Netherlands
| | - S Edwards
- 4 Adelaide Health Technology Assessment, School of Public Health, University of Adelaide, Adelaide, Australia
| | - J A Kaidonis
- 1 School of Dentistry, University of Adelaide, Adelaide, Australia
| | - C Hall
- 5 Future Industries Institute, University of South Australia, Mawson Lakes, Australia
| | - D Lekkas
- 1 School of Dentistry, University of Adelaide, Adelaide, Australia
| | - P Wetselaar
- 2 Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute Amsterdam, VU University Amsterdam, Amsterdam, Netherlands
| | - A H Brook
- 1 School of Dentistry, University of Adelaide, Adelaide, Australia.,6 Institute of Dentistry, Queen Mary University of London, London, UK
| | - F Lobbezoo
- 2 Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute Amsterdam, VU University Amsterdam, Amsterdam, Netherlands
| | - G C Townsend
- 1 School of Dentistry, University of Adelaide, Adelaide, Australia
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Arsecularatne J, Chung N, Hoffman M. An in vitro study of the wear behaviour of dental composites. BIOSURFACE AND BIOTRIBOLOGY 2016. [DOI: 10.1016/j.bsbt.2016.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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20
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Raphael KG, Santiago V, Lobbezoo F. Bruxism is a continuously distributed behaviour, but disorder decisions are dichotomous (Response to letter by Manfredini, De Laat, Winocur, & Ahlberg (2016)). J Oral Rehabil 2016; 43:802-3. [PMID: 27558868 DOI: 10.1111/joor.12425] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- K G Raphael
- Department of Oral & Maxillofacial Pathology, Radiology, and Medicine, New York University College of Dentistry, New York, NY, USA.
| | - V Santiago
- Department of Oral & Maxillofacial Pathology, Radiology, and Medicine, New York University College of Dentistry, New York, NY, USA
| | - F Lobbezoo
- Department of Oral & Maxillofacial Pathology, Radiology, and Medicine, New York University College of Dentistry, New York, NY, USA.,Department of Oral Health Sciences, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute Amsterdam, University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
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