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Thadathil Varghese J, Raju R, Farrar P, Prentice L, Prusty BG. Comparative analysis of self-cure and dual cure-dental composites on their physico-mechanical behaviour. Aust Dent J 2024; 69:124-138. [PMID: 38131257 DOI: 10.1111/adj.13004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND Clinical practitioners may have become familiar with the rapid transformation of dental composites. However, they may not scientifically understand the factors influencing the mechanical and physical properties. Scientific knowledge of filler-resin interaction can significantly improve clinical understanding of resin composites. Several independent studies have examined the mechanical and physico-mechanical properties of dental resin composites; however, no comprehensive study has examined the influence of fillers and resin materials on the physico-mechanical properties of both self-cure and dual-cure composites. METHODS This study performed investigations on the physico-mechanical behaviour of four commercially available dual-cure dental composites (Bioactive, Fill Up!, Surefil One, Cention N) and two commercially available self-cure dental composites (Stela Capsule and Stela Automix). Test specimens for flexural and compressive strength, microhardness, fracture toughness, and hydrolytic behaviour were prepared and tested as per respective standards. The data sets were statistically analysed using one-way ANOVA and Tukey's post-hoc comparison. RESULTS There was a substantial variation in flexural strength and modulus values in this study, ranging from 32.0 to 113.4 MPa and 2.36 to 12.07 GPa, respectively. Similarly, there were significant differences in compressive strength between the materials in this study, ranging from 119.3 to 223.5 MPa. The highest fracture toughness value was found to be 1.41 MPa.m0.5, while the lowest value was 0.43 MPa.m0.5. Variations in surface microhardness were significant (24.11-68.0 N/mm2), which correlated with the filler content. Water sorption and solubility demonstrated high variations among materials, with Surefil One exceeding ISO 4049 thresholds significantly. CONCLUSIONS A linear correlation can be established between surface microhardness (HV) and flexural and compressive moduli, as well as filler content (wt.%). However, both flexural and compressive strengths are impacted by the resin's constituent monomers and the resin-filler matrix's cross-linking capability. Additionally, factors such as filler size, shape, and the cross-linking ability of the resin-filler matrix play a crucial role in fracture toughness and the propagation of cracks within the restoration. Also, resin monomers and filler particle size affect the hydrolytic degradation characteristics of composites, which can also affect their mechanical properties. © 2023 Australian Dental Association.
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Affiliation(s)
- J Thadathil Varghese
- School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - R Raju
- ARC Centre for Automated Manufacture of Advanced Composites, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - P Farrar
- SDI Limited, Bayswater, Victoria, Australia
| | - L Prentice
- SDI Limited, Bayswater, Victoria, Australia
| | - B G Prusty
- School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, New South Wales, Australia
- ARC Centre for Automated Manufacture of Advanced Composites, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Australian Composites Manufacturing CRC Ltd. (ACM CRC), University of New South Wales, Sydney, New South Wales, Australia
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Thyvalikakath T, Siddiqui ZA, Eckert G, LaPradd M, Duncan WD, Gordan VV, Rindal DB, Jurkovich M, Gilbert GH. Survival analysis of posterior composite restorations in National Dental PBRN general dentistry practices. J Dent 2024; 141:104831. [PMID: 38190879 PMCID: PMC10866618 DOI: 10.1016/j.jdent.2024.104831] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 01/01/2024] [Accepted: 01/02/2024] [Indexed: 01/10/2024] Open
Abstract
OBJECTIVE Quantify the survival of posterior composite restorations (PCR) placed during the study period in permanent teeth in United States (US) general dental community practices and factors predictive of that survival. METHODS A retrospective cohort study was conducted utilizing de-identified electronic dental record (EDR) data of patients who received a PCR in 99 general dentistry practices in the National Dental Practice-Based Research Network (Network). The final analyzed data set included 700,885 PCRs from 200,988 patients. Descriptive statistics and Kaplan Meier (product limit) estimator were performed to estimate the survival rate (defined as the PCR not receiving any subsequent treatment) after the first PCR was observed in the EDR during the study time. The Cox proportional hazards model was done to account for patient- and tooth-specific covariates. RESULTS The overall median survival time was 13.3 years. The annual failure rates were 4.5-5.8 % for years 1-5; 5.3-5.7 %, 4.9-5.5 %, and 3.3-5.2 % for years 6-10, 11-15, and 16-20, respectively. The failure descriptions recorded for < 7 % failures were mostly caries (54 %) and broken or fractured tooth/restorations (23 %). The following variables significantly predicted PCR survival: number of surfaces that comprised the PCR; having at least one interproximal surface; tooth type; type of prior treatment received on the tooth; Network region; patient age and sex. Based on the magnitude of the multivariable estimates, no single factor predominated. CONCLUSIONS This study of Network practices geographically distributed across the US observed PCR survival rates and predictive factors comparable to studies done in academic settings and outside the US. CLINICAL SIGNIFICANCE Specific baseline factors significantly predict the survival of PCRs done in US community dental practices.
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Affiliation(s)
- Thankam Thyvalikakath
- Office of Dental Informatics & Digital Health, Indiana University School of Dentistry, IUPUI, Research Scientist & Director, Dental Informatics, Center for Biomedical Informatics, Regenstrief Institute, Inc., OH 144A, 415 Lansing Street, Indianapolis, IN 46202, USA.
| | - Zasim Azhar Siddiqui
- West Virginia University School of Pharmacy, Morgantown, WV, USA; Department of Public Health and Dental Informatics, Indiana University School of Dentistry, IUPUI, Indianapolis, IN 46202, USA
| | - George Eckert
- Department of Biostatistics and Health Data Science, Indiana University School of Medicine, 340W 10th St, Indianapolis, IN 46202, USA
| | - Michelle LaPradd
- Department of Biostatistics and Health Data Science, Indiana University School of Medicine, 340W 10th St, Indianapolis, IN 46202, USA; Syneos Health, 1030 Sync St, Morrisville, NC 27560, USA
| | - William D Duncan
- Department of Community Dentistry, University of Florida, College of Dentistry, Gainesville, FL, USA; Biomedical Data Science and Shared Resource, Roswell Park Cancer Center, Buffalo, NY, USA
| | - Valeria V Gordan
- University of Florida, College of Dentistry, Gainesville, FL, USA
| | - D Brad Rindal
- 8170 33rd Avenue South | P.O. Box 1524, MS 23301A Minneapolis MN 55440, USA
| | - Mark Jurkovich
- HealthPartners Institute, Minneapolis MN, USA; 8170 33rd Ave S, Bloomington, MN 55440, USA
| | - Gregg H Gilbert
- Department of Clinical and Community Sciences, School of Dentistry, SDB Room 109, University of Alabama at Birmingham, Birmingham, AL, USA; National Dental PBRN Collaborative Group, 1720 University Blvd, Birmingham, AL 35294, USA; University of Alabama at Birmingham, Birmingham, AL, USA
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Naguib G, Maghrabi AA, Mira AI, Mously HA, Hajjaj M, Hamed MT. Influence of inorganic nanoparticles on dental materials' mechanical properties. A narrative review. BMC Oral Health 2023; 23:897. [PMID: 37990196 PMCID: PMC10662115 DOI: 10.1186/s12903-023-03652-1] [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: 09/13/2023] [Accepted: 11/09/2023] [Indexed: 11/23/2023] Open
Abstract
Inorganic nanoparticles have been widely incorporated in conventional dental materials to help in improving their properties. The literature has shown that incorporating nanoparticles in dental materials in different specialties could have a positive effect on reinforcing the mechanical properties of those materials; however, there was no consensus on the effectiveness of using nanoparticles in enhancing the mechanical properties of dental materials, due to the variety of the properties of nanoparticles itself and their effect on the mechanical properties. This article attempted to analytically review all the studies that assessed the effect of different types of inorganic nanoparticles on the most commonly used dental materials in dental specialties such as polymethyl methacrylate, glass ionomer cement, resin composite, resin adhesive, orthodontic adhesive, and endodontic sealer. The results had shown that those inorganic nanoparticles demonstrated positive potential in improving those mechanical properties in most of the dental materials studied. That potential was attributed to the ultra-small sizes and unique physical and chemical qualities that those inorganic nanoparticles possess, together with the significant surface area to volume ratio. It was concluded from this comprehensive analysis that while a definitive recommendation cannot be provided due to the variety of nanoparticle types, shapes, and incorporated dental material, the consensus suggests using nanoparticles in low concentrations less than 1% by weight along with a silane coupling agent to minimize agglomeration issues and benefit from their properties.
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Affiliation(s)
- Ghada Naguib
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
- Department of Oral Biology, Cairo University School of Dentistry, Cairo, Egypt.
| | | | - Abdulghani I Mira
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hisham A Mously
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Maher Hajjaj
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohamed T Hamed
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Fixed Prosthodontics, Cairo University School of Dentistry, Cairo, Egypt
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Aram A, Hong H, Song C, Bass M, Platt JA, Chutinan S. Physical Properties and Clinical Performance of Short Fiber Reinforced Resin-based Composite in Posterior Dentition: Systematic Review and Meta-analysis. Oper Dent 2023; 48:E119-E136. [PMID: 37655625 DOI: 10.2341/22-003-lit] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2023] [Indexed: 09/02/2023]
Abstract
OBJECTIVE This study compares the physical properties and clinical performance of short fiber reinforced composites (SFRC) to those of particulate-filled resin-based composites (PFRC) for class I and II direct restorations in permanent dentition. METHODS Systematic review and meta-analysis was conducted using PubMed, Embase (Elsevier), and Dentistry and Oral Sciences Source (EBSCO) databases. The outcomes evaluated were physical properties including flexural strength, flexural modulus, elastic modulus, microhardness, shrinkage, fracture toughness, degree of conversion, and depth of cure. Clinical performance was evaluated with a systematic review. RESULTS The meta-analyses favored SFRC for flexural strength and fracture toughness compared to every PFRC subgroup, with a high quality of evidence. For all other properties, the meta-analyses favored SFRC to overall PFRC, with some non-significant differences with certain PFRC subgroups. The most recent clinical trial showed SFRC performed similarly to PFRC, however older studies suggest inferior surface texture and discoloration of SFRC compared to PFRC. CONCLUSION This study can aid dental professionals in clinical decision making, supporting that SFRC offers improved physical properties, especially fracture resistance and flexural strength, compared to PFRC.
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Affiliation(s)
- A Aram
- Ariana Aram, DMD, Harvard School of Dental Medicine, Boston, MA, USA
| | - H Hong
- Houlin Hong, MPH, Department of Community Health and Social Sciences, CUNY School of Public Health and Health Policy, New York, NY, USA
| | - C Song
- Crystal Song, BS, Harvard School of Dental Medicine, Boston, MA, USA
| | - M Bass
- Michelle Bass, PhD, MSI, AHIP, Pennsylvania Hospital Library, Pennsylvania Hospital, Philadelphia, PA, USA
| | - J A Platt
- Jeffrey A Platt, DDS, MS, Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, USA
| | - S Chutinan
- *Supattriya Chutinan, DDS, MSD, Department of Restorative Dentistry and Biomaterials Science, Harvard School of Dental Medicine, Boston, MA, USA
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Fracture toughness and brittleness of novel CAD/CAM resin composite block. Dent Mater 2022; 38:e308-e317. [DOI: 10.1016/j.dental.2022.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 10/04/2022] [Accepted: 11/11/2022] [Indexed: 11/24/2022]
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Treatment of Tooth Wear Using Direct or Indirect Restorations: A Systematic Review of Clinical Studies. Bioengineering (Basel) 2022; 9:bioengineering9080346. [PMID: 36004871 PMCID: PMC9404995 DOI: 10.3390/bioengineering9080346] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/17/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022] Open
Abstract
Tooth wear is considered a well-developed issue in daily clinical practice; however, there is no standard protocol for treatment. The aim of this manuscript was to systematically review the literature to evaluate the clinical outcomes of direct or indirect restorations for treating tooth wear. A literature search was conducted through the PubMed MedLine, Scopus, ISI Web of Science, Scielo, and EMBASE databases up to 29 April 2022. Clinical studies evaluating the clinical performance of direct or indirect restorations for treating tooth wear for a minimum follow-up of 6 months were included in the review. A total of 2776 records were obtained from the search databases. After full-text reading, 16 studies were included in the qualitative analysis. Considering the high heterogenicity of the studies included, a meta-analysis could not be performed. All studies included the rehabilitation of anterior and posterior teeth with extensive wear, using both indirect and direct restorations for a maximum follow-up of 10 years. Restoration materials included ceramo-metal crowns, full gold crowns, lithium disilicate ceramic, zirconia, polymer infiltrated ceramic networks, and resin composites. Most of the reports assessed the survival rate of the restorations and the clinical features using the United States Public Health Service (USPHS) Evaluation System criteria. Contradictory discoveries were perceived concerning the type of restoration with better clinical performance. Considering the current literature available, there is no evidence in the superiority of any restoration technique to ensure the highest clinical performance for treating tooth wear.
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Barot T, Rawtani D, Kulkarni P. Physicochemical and biological assessment of silver nanoparticles immobilized Halloysite nanotubes-based resin composite for dental applications. Heliyon 2020; 6:e03601. [PMID: 32195405 PMCID: PMC7078557 DOI: 10.1016/j.heliyon.2020.e03601] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 02/24/2020] [Accepted: 03/11/2020] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE The purpose of this study was to investigate the effect of Silver nanoparticle immobilized Halloysite Nanotubes (HNT/Ag) fillers on physicochemical, mechanical, and biological properties of novel experimental dental resin composite in order to compare with the properties of corresponding composites containing conventional glass fillers. METHODS Dental resin (Bis-GMA/TEGDMA with ratio 70/30) composites were prepared by incorporation of varied mass fraction of HNT/Ag. Experimental composites were divided into six groups, one control group and five experimental groups containing mass fraction 1 to 10.0 wt. % of HNT/Ag. Mechanical properties of the dental composites were recorded. Degree of conversion and depth of cure of the dental resin composites were assessed. Antimicrobial properties were assessed using agar diffusion test and evaluation of cytotoxicity were performed on NIH-3T3 cell line. RESULTS The inclusion of mass fractions (1-5 wt. %) of the HNT/Ag in dental resins composites, significantly improved mechanical properties. While, addition of larger mass fractions (7.5 and 10 wt. %) of the HNT/Ag did not show further improvement in the mechanical properties of dental resins composites. Theses composites also demonstrated satisfactory depth of cure and degree of conversion. A significant antibacterial activity was observed on S. mutans. No significant cytotoxicity was found on NIH-3T3 cell lines. CONCLUSION The incorporation of HNT/Ag in Bis-GMA/TEGDMA dental resins composites resulted in enhancement in mechanical as well as biological properties for dental applications. CLINICAL SIGNIFICANCE HNT/Ag containing dental composite is proposed to be highly valuable in the development of restorative dental material for patients with high risk of dental caries.
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Affiliation(s)
| | - Deepak Rawtani
- Gujarat Forensic Sciences University, Nr. DFS Head Quarters, Sector 9, Gandhinagar, Gujarat, 382007, India
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Barot T, Rawtani D, Kulkarni P, Hussain CM, Akkireddy S. Physicochemical and biological assessment of flowable resin composites incorporated with farnesol loaded halloysite nanotubes for dental applications. J Mech Behav Biomed Mater 2020; 104:103675. [PMID: 32174431 DOI: 10.1016/j.jmbbm.2020.103675] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 12/23/2022]
Abstract
The aim of this study was to fabricate flowable resin composites, by incorporating Farnesol loaded Halloysite Nanotubes (Fa-HNT) as a filler and evaluate their physicochemical as well as biological properties. Chemical and morphological characterization of antibacterial filler, Fa-HNT were performed using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM). The antibacterial filler was mixed into composite material consisting of methacrylate monomers and dental glass fillers at concentrations of 1-20% (wt./wt.). It was observed that addition of mass fractions of Fa-HNT causes enhancement of compressive strength as well as flexural modulus of the composite. However, it significantly decreases flexural strength and degree of conversion. A significant antibacterial activity of dental composite was observed with increase in the area of zone of inhibition against the strains of Streptococcus mutans (S. mutans). There was no cytotoxicity observed by Fa-HNT resin composites on NIH-3T3 (mouse embryonic fibroblast cells) cell lines. A favourable integration of antibacterial filler with significant mechanical properties was achieved at concentrations from 7 to 13 wt% of Fa-HNT in dental composites, which is desirable in dentistry.
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Affiliation(s)
- Tejas Barot
- Institute of Research and Development, Gujarat Forensic Sciences University, sector 9, near Police Bhawan, Gandhinagar-382007, Gujarat, India
| | - Deepak Rawtani
- Institute of Research and Development, Gujarat Forensic Sciences University, sector 9, near Police Bhawan, Gandhinagar-382007, Gujarat, India.
| | - Pratik Kulkarni
- Institute of Research and Development, Gujarat Forensic Sciences University, sector 9, near Police Bhawan, Gandhinagar-382007, Gujarat, India
| | - Chaudhery Mustansar Hussain
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, 161 Warren St., University Heights, Newark, NJ 07102, USA
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Aregawi W, Darvell BW, Fok ASL. Fracture mechanics of circular discs with a V-notch subjected to wedging. Dent Mater 2020; 36:413-419. [PMID: 32008749 DOI: 10.1016/j.dental.2020.01.010] [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: 09/06/2019] [Revised: 12/19/2019] [Accepted: 01/14/2020] [Indexed: 11/20/2022]
Abstract
OBJECTIVE A method proposed for determining the fracture toughness (FT) of dental materials involves a 'roller' wedging open a V-notch in a cylindrical specimen. There are a number of problems with the design of this test and its mechanical analysis, and thus with the validity of the results obtained, were it to be used. Firstly, friction is ignored in calculating the horizontal wedging force. Secondly, the test specimen does not make use of a pre-crack at the notch tip. The aim of this study was to evaluate the effects of these factors on the FT calculated. METHODS An analytical solution for the mode-I stress intensity factor (KI) of the compact tension specimen, which bears some similarities, is taken to be applicable. The mechanics of the specimen has been reanalysed, with a finite-element study of the resultant stresses, and compared with the compact-tension test. RESULTS The assumed analytical solution can provide accurate estimates for KI for the V notched specimen. However, the apparent agreement is due to the fortuitous combination of an overestimated horizontal wedging force and an underestimated stress singularity at the crack tip. In any case, ignoring friction will lead to an overestimate of FT. SIGNIFICANCE It is concluded that the test as presented is invalid.
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Affiliation(s)
- Wondwosen Aregawi
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, United States
| | - Brian W Darvell
- Dental Materials Science, School of Dentistry, University of Birmingham, UK
| | - Alex S L Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, United States.
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Wear Characteristics of Dental Ceramic CAD/CAM Materials Opposing Various Dental Composite Resins. MATERIALS 2019; 12:ma12111839. [PMID: 31174298 PMCID: PMC6600963 DOI: 10.3390/ma12111839] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/22/2019] [Accepted: 06/03/2019] [Indexed: 11/17/2022]
Abstract
The aim of this study was to evaluate the wear properties of opposed dental ceramic restorative CAD/CAM materials and several posterior direct restorative composite resins. Three kinds of dental ceramics CAD/CAM materials (monolithic zirconia, lithium disilicate, leucite) and four dental composite resins—that is, MI Gracefil, Gradia Direct P, Estelite Σ Quick, and Filtek Supreme Ultra—were used in this study. For each of the 12 groups (three ceramics × four composite resins), five each of a canine-shaped ceramic specimen and a cuboidal shape opposing composite resin were prepared. All of the specimens were tested in a thermomechanical loading machine (50 N, 100,000 cycles, 5/55 °C). Wear losses of ceramic specimens and composite resin specimens were evaluated using a three-dimensional profiling system and an electronic scale, respectively. Statistical analyses were performed using the Kruskal–Wallis test and Mann–Whitney U test with Bonferroni’s correction. Zirconia showed significantly less volumetric loss than lithium disilicate or leucite regardless of composite resin type (p > 0.05/3 = 0.017), and that Estelite Σ Quick showed significantly more weight loss than Filtek Supreme Ultra, MI Gracefil, or Gradia Direct P regardless of ceramic type (p > 0.05/6 = 0.083). Zirconia showed less volumetric loss than lithium disilicate or leucite. Some composite resins opposing ceramics showed considerable weight loss.
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Maas MS, Alania Y, Natale LC, Rodrigues MC, Watts DC, Braga RR. Trends in restorative composites research: what is in the future? Braz Oral Res 2017; 31:e55. [PMID: 28902235 DOI: 10.1590/1807-3107bor-2017.vol31.0055] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 05/22/2017] [Indexed: 01/12/2023] Open
Abstract
Clinical trials have identified secondary caries and bulk fracture as the main causes for composite restoration failure. As a measure to avoid frequent reinterventions for restoration replacement, composites with some sort of defense mechanism against biofilm formation and demineralization, as well as materials with lower susceptibility to crack propagation are necessary. Also, the restorative procedure with composites are very time-consuming and technically demanding, particularly concerning the application of the adhesive system. Therefore, together with bulk-fill composites, self-adhesive restorative composites could reduce operator error and chairside time. This literature review describes the current stage of development of remineralizing, antibacterial and self-healing composites. Also, an overview of the research on fiber-reinforced composites and self-adhesive composites, both introduced for clinical use in recent years, is presented.
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Affiliation(s)
- Mariel Soeiro Maas
- Universidade de São Paulo - USP, School of Dentistry,Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
| | - Yvette Alania
- Universidade de São Paulo - USP, School of Dentistry,Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
| | - Livia Camargo Natale
- Universidade de São Paulo - USP, School of Dentistry,Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
| | - Marcela Charantola Rodrigues
- Universidade de São Paulo - USP, School of Dentistry,Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
| | - David Christopher Watts
- University of Manchester School of Medical Sciences, Division of Dentistry, Manchester, United Kingdom
| | - Roberto Ruggiero Braga
- Universidade de São Paulo - USP, School of Dentistry,Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
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Replacement of glass particles by multidirectional short glass fibers in experimental composites: Effects on degree of conversion, mechanical properties and polymerization shrinkage. Dent Mater 2016; 32:e204-10. [PMID: 27372238 DOI: 10.1016/j.dental.2016.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/22/2016] [Accepted: 06/16/2016] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To test the null hypothesis that the replacement of a small fraction of glass particles with random short glass fibers does not affect degree of conversion (DC), flexural strength (FS), fracture toughness (FT) and post-gel polymerization shrinkage (PS) of experimental composites. METHODS Four experimental photocurable composites containing 1 BisGMA:1 TEGDMA (by weight) and 60vol% of fillers were prepared. The reinforcing phase was constituted by barium glass particles (2μm) and 0%, 2.5%, 5.0% or 7.5% of silanated glass fibers (1.4mm in length, 7-13μm in diameter). DC (n=4) was obtained using near-FTIR. FS (n=10) was calculated via biaxial flexural test and FT (n=10) used the "single edge notched beam" method. PS at 5min (n=8) was determined using the strain gage method. Data were analyzed by ANOVA/Tukey test (DC, FS, PS) or Kruskal-Wallis/Dunn's test (FT, alpha: 5% for both tests). RESULTS DC was similar among groups (p>0.05). Only the composite containing 5.0% of fibers presented lower FS than the control (p<0.001). FT increased significantly between the control (1.3±0.17MPam(0.5)) and the composites containing either 5.0% (2.7±0.6MPam(0.5)) or 7.5% of fibers (2.8±0.6MPam(0.5), p<0.001). PS in relation to control was significantly reduced at 2.5% fibers (from 0.81±0.13% to 0.57±0.13%) and further reduced between 5.0% and 7.5% (from 0.42±0.12% to 0.23±0.07%, p<0.001). SIGNIFICANCE The replacement of a small fraction of filler particles with glass fibers significantly increased fracture toughness and reduced post-gel shrinkage of experimental composites.
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MESE A, EA PALAMARA J, BAGHERI R, FANI M, BURROW MF. Fracture toughness of seven resin composites evaluated by three methods of mode I fracture toughness ( KIc). Dent Mater J 2016; 35:893-899. [DOI: 10.4012/dmj.2016-140] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Ayse MESE
- Department of Prosthodontics, School of Dentistry, Dicle University
| | - Joseph EA PALAMARA
- Restorative Section, Melbourne Dental School, The University of Melbourne
| | - Rafat BAGHERI
- Restorative Section, Melbourne Dental School, The University of Melbourne
- Department of Dental Materials and Biomaterials Research Center, School of Dentistry, Shiraz University of Medical Sciences
| | - Mehdi FANI
- Department of Dental Materials and Biomaterials Research Center, School of Dentistry, Shiraz University of Medical Sciences
| | - Michael F. BURROW
- Restorative Section, Melbourne Dental School, The University of Melbourne
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SHINKAI K, SUZUKI S. Effect of cyclic impact loading on the surface properties of flowable resin composites. Dent Mater J 2014; 33:874-9. [DOI: 10.4012/dmj.2014-010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Sumino N, Tsubota K, Takamizawa T, Shiratsuchi K, Miyazaki M, Latta MA. Comparison of the wear and flexural characteristics of flowable resin composites for posterior lesions. Acta Odontol Scand 2013; 71:820-7. [PMID: 23638859 DOI: 10.3109/00016357.2012.734405] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To determine the localized wear and flexural properties of flowable resin composites for posterior lesions compared with universal resin composites produced by the same manufacturers. METHODS Ten specimens of each of three flowable resins, G-ænial Universal Flo, G-ænial Flo and Clearfil Majesty Flow, and the corresponding resin composite materials, Kalore and Clearfil Majesty Esthetics, were prepared in custom fixtures and subjected to 400,000 wear machine cycles to simulate localized wear. The total maximum depth and volume loss of the wear facets was calculated for each specimen using a profilometer. A three-point bending test was performed to determine the flexural strength, modulus of elasticity and resilience. Values were statistically compared using one-way analysis of variance (ANOVA) followed by Tukey's Honestly Significant Difference (HSD) test. RESULTS The wear depth ranged from 58.3-126.9 m and the volumetric loss ranged from 0.019-0.049 mm(3), with significant differences observed between restorative materials. The wear depth of G-ænial Universal Flo was significantly smaller than those of the other resin composites tested. The flexural strengths and elastic modulus ranged from 90.5-135.1 MPa and from 4.7-7.6 GPa, respectively. A significantly greater flexural strength and higher elastic modulus was found for G-ænial Universal Flo than the other composites. CONCLUSIONS The wear and mechanical properties of the flowable resin composites tested suggested improved performance compared with universal resin composites.
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Affiliation(s)
- Natsu Sumino
- Department of Operative Dentistry, Nihon University School of Dentistry, Kanda-Surugadai, Chiyoda-ku, Tokyo, Japan
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Guo G, Fan Y, Zhang JF, Hagan JL, Xu X. Novel dental composites reinforced with zirconia-silica ceramic nanofibers. Dent Mater 2011; 28:360-8. [PMID: 22153326 DOI: 10.1016/j.dental.2011.11.006] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 08/30/2011] [Accepted: 11/07/2011] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To fabricate and characterize dental composites reinforced with various amounts of zirconia-silica (ZS) or zirconia-yttria-silica (ZYS) ceramic nanofibers. METHODS Control composites (70 wt% glass particle filler, no nanofibers) and experimental composites (2.5, 5.0, and 7.5 wt% ZS or ZYS nanofibers replacing glass particle filler) were prepared by blending 29 wt% dental resin monomers, 70 wt% filler, and 1.0 wt% initiator, and polymerized by either heat or dental curing light. Flexural strength (FS), flexural modulus (FM), energy at break (EAB), and fracture toughness (FT) were tested after the specimens were stored in 37°C deionized water for 24h, 3 months, or 6 months. Degree of conversion (DC) of monomers in composites was measured using Fourier transformed near-infrared (FT-NIR) spectroscopy. Fractured surfaces were observed by field-emission scanning electron microscope (FE-SEM). The data were analyzed using ANOVA with Tukey's Honestly Significant Differences test used for post hoc analysis. RESULTS Reinforcement of dental composites with ZS or ZYS nanofibers (2.5% or 5.0%) can significantly increase the FS, FM and EAB of dental composites over the control. Further increase the content of ZS nanofiber (7.5%), however, decreases these properties (although they are still higher than those of the control). Addition of nanofibers did not decrease the long-term mechanical properties of these composites. All ZS reinforced composites (containing 2.5%, 5.0% and 7.5% ZS nanofibers) exhibit significantly higher fracture toughness than the control. The DC of the composites decreases with ZS nanofiber content. SIGNIFICANCE Incorporation of ceramic nanofibers in dental composites can significantly improve their mechanical properties and fracture toughness and thus may extend their service life.
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Affiliation(s)
- Guangqing Guo
- Department of Comprehensive Dentistry and Biomaterials, Louisiana State University Health Sciences Center, School of Dentistry, New Orleans, LA 70119, USA
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Elbishari H, Satterthwaite J, Silikas N. Effect of filler size and temperature on packing stress and viscosity of resin-composites. Int J Mol Sci 2011; 12:5330-8. [PMID: 21954362 PMCID: PMC3179169 DOI: 10.3390/ijms12085330] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 07/12/2011] [Accepted: 08/12/2011] [Indexed: 12/02/2022] Open
Abstract
The objective of this study was to investigate the effect of filler size on the packing stress and viscosity of uncured resin-composite at 23 °C and 37 °C. A precision instrument used was designed upon the penetrometer principle. Eight resin-composite materials were tested. Packing-stress ranged from 2.60 to 0.43 MPa and viscosity ranged from 2.88 to 0.02 MPa.s at 23 °C. Values for both properties were reduced significantly at 37 °C. Statistical analysis, by ANOVA and post hoc methods, were carried out to check any significant differences between materials tested (P < 0.05). Conclusions: Filler size and distribution will affect the viscosity and packing of resin-composites during cavity placement.
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Affiliation(s)
- Haitham Elbishari
- School of Dentistry, University of Manchester, Higher Cambridge Street, Manchester M15 6FH, UK; E-Mails: (J.S.); (N.S.)
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Balkenhol M, Köhler H, Orbach K, Wöstmann B. Fracture toughness of cross-linked and non-cross-linked temporary crown and fixed partial denture materials. Dent Mater 2009; 25:917-28. [PMID: 19249090 DOI: 10.1016/j.dental.2009.01.099] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 10/07/2008] [Accepted: 01/20/2009] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Temporary crowns and fixed partial dentures are exposed to considerable functional loading, which places severe demands on the biomaterials used for their fabrication (= temporary crown & bridge materials, t-c&b). As the longevity of biopolymers is influenced by the ability to withstand a crack propagation, the aim of this study was to investigate the fracture toughness of cross-linked and non-cross-linked t-c&bs. METHODS Four different t-c&bs (Luxatemp AM Plus, Protemp 3 Garant, Structur Premium, Trim) were used to fabricate bar shaped specimens (2mmx5mmx25mm, ISO 13586). A notch (depth 2.47mm) was placed in the center of the specimen using a diamond cutting disc and a sharp pre-crack was added using a razor blade. 60 specimens per material were subjected to different storage conditions (dry and water 37 degrees C: 30min, 60min, 4h, 24h, 168h; thermocycling 5-55 degrees C: 168h) prior to fracture (3-point bending setup). The fracture sites were inspected using SEM analysis. Data was subjected to parametric statistics (p=0.05). RESULTS The K(IC) values varied between 0.4 and 1.3MPam(0.5) depending on the material and storage time. Highest K(IC) were observed for Protemp 3 Garant. Fracture toughness was significantly affected by thermocycling for all dimethacrylates (p<0.05) except for Structur Premium. All dimethacrylates showed a linear-elastic fracture mechanism, whereas the monomethacrylate showed an elasto-plastic fracture mechanism. SIGNIFICANCE Dimethacrylates exhibit a low resistance against crack propagation immediately after curing. In contrast, monomethacrylates may compensate for crack propagation due to plastic deformation. However, K(IC) is compromised with increasing storage time.
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Affiliation(s)
- Markus Balkenhol
- Department of Prosthetic Dentistry, Justus-Liebig-University, Schlangenzahl 14, D-35392 Giessen, Germany.
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19
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Investigations on mechanical behaviour of dental composites. Clin Oral Investig 2009; 13:427-38. [DOI: 10.1007/s00784-009-0258-4] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Revised: 02/04/2009] [Accepted: 02/05/2009] [Indexed: 10/21/2022]
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Cho SD, Bulpakdi P, Matis BA, Platt JA. Effect of Bleaching on Fracture Toughness of Resin Composites. Oper Dent 2009; 34:703-8. [DOI: 10.2341/08-120-l] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Bleaching after composite placement does not have a significant adverse effect on the fracture toughness of composite materials.
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IRIE M, TJANDRAWINATA R, E L, YAMASHIRO T, SUZUKI K. Flexural Performance of Flowable versus Conventional Light-cured Composite Resins in a Long-term in vitro Study. Dent Mater J 2008; 27:300-9. [DOI: 10.4012/dmj.27.300] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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da Rosa Rodolpho PA, Cenci MS, Donassollo TA, Loguércio AD, Demarco FF. A clinical evaluation of posterior composite restorations: 17-year findings. J Dent 2006; 34:427-35. [PMID: 16314023 DOI: 10.1016/j.jdent.2005.09.006] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 09/13/2005] [Accepted: 09/20/2005] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE Since an increasing number of composite restorations in posterior teeth are placed as a routine, this study was conducted to evaluate long-term survival of these restorations placed in general practice. METHODS Patients from a private dental office that received restorations in posterior teeth between 1987 and 1988 with P-50 (3M) or Herculite XR (Kerr) resin composites were selected and invited to participate. Restorations were placed under rubber dam isolation. Dentine walls were covered with glass ionomer cement, and composites were placed according to manufacturer's instructions. Thirty-eight patients agreed to participate and signed an informed consent prior to the evaluation. Two calibrated operators worked independently in the evaluation, using modified USPHS criteria. Survival of restorations or subsets of restorations grouped on the basis of variables (material, tooth, cavity type and size) was determined using Kaplan-Meier survival curves. RESULTS Ninety-eight failures were recorded among the 282 restorations providing a crude estimate of 34.8% failures. The survival rate was not significant for material (p=0.92) but was significant between tooth (lower premolars and lower molars, p<0.0001), cavity type (p<0.001) and size (p<0.001). The majority of restorations exhibited A or B scores for the evaluated criteria. The main failure cause was fracture of both composites. CONCLUSIONS The clinical performance of posterior resin composite restorations evaluated was acceptable after 17-year evaluation. However, the probability of failure of resin composite restorations in molars, Class II, and large restorations is higher.
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Affiliation(s)
- Paulo Antônio da Rosa Rodolpho
- Graduate Program in Dentistry, Cariology Area, Faculty of Dentistry of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil
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Papadogiannis Y, Lakes RS, Palaghias G, Helvatjoglu-Antoniades M, Papadogiannis D. Fatigue of packable dental composites. Dent Mater 2006; 23:235-42. [PMID: 16490246 DOI: 10.1016/j.dental.2006.01.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 01/12/2006] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The purpose of the study was to measure the fatigue properties of four dental resin composites using a dynamic mechanical analysis and to relate the results with viscoelastic properties. METHODS Dynamic torsional loading was conducted at resonance at 30-50Hz. Specimens were thoroughly cured and tested dry at 21 degrees C. RESULTS All of the specimens showed a loss of strength following repeated stress, due to material fatigue. The material with the highest shear modulus had the lowest damping and the highest fatigue strength. SIGNIFICANCE Dental composites exhibit a modest loss of strength due to fatigue. Since mastication involves many cycles of stress during the life of a restoration, fatigue properties should be taken into account in restoration design.
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Affiliation(s)
- Y Papadogiannis
- Aristotle University of Thessaloniki, School of Dentistry, Department of Operative Dentistry, Thessaloniki, Greece.
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Brandão L, Adabo GL, Vaz LG, Saad JRC. Compressive strength and compressive fatigue limit of conventional and high viscosity posterior resin composites. Braz Oral Res 2006; 19:272-7. [PMID: 16491255 DOI: 10.1590/s1806-83242005000400007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to compare the compressive strengths and compressive fatigue limits of three posterior composite resins (Filtek P-60, Surefil and Prodigy Condensable) and a universal restorative composite (Z-100). Cylindrical specimens (8 mm in length x 4 mm in diameter) were used. The dynamic test was performed using the staircase method, and the ratio between compressive fatigue limit and compressive resistance was also calculated (n = 15). The compressive strength and compressive fatigue limit data were analyzed by Anova and Tukeys test. The Z-100 composite demonstrated higher compression strength (307.20 MPa) than Surefil (266.93 MPa) and Prodigy Condensable (222.08 MPa). The resistance of Filtek P-60 (270.44 MPa) was similar to the resistances of Z-100 and Surefil, while Prodigy Condensable presented the lowest compressive strength. In the compressive fatigue limit tests, Filtek P-60 demonstrated a higher value (184.20 MPa) than Prodigy Condensable (155.50 MPa). Surefil (165.74 MPa) and Z-100 (161.22 MPa) presented limits similar to those of Filtek P-60 and Prodigy Condensable. The compressive fatigue limit/compressive strength ratio was 70.01% for Prodigy Condensable, 68.11% for Filtek P-60, 62.09% for Surefil and 52.48% for Z-100. It was concluded that the Z-100 universal composite was more sensitive to the dynamic test than the high viscosity materials.
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Affiliation(s)
- Letícia Brandão
- Department of Restorative Dentistry, Federal University of Santa Maria
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Tanimoto Y, Nishiwaki T, Nemoto K. Dynamic Viscoelastic Behavior of Dental Composites Measured by Split Hopkinson Pressure Bar. Dent Mater J 2006; 25:234-40. [PMID: 16916223 DOI: 10.4012/dmj.25.234] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The present study evaluated the dynamic viscoelastic behavior of commercially available dental composites by a Split Hopkinson pressure bar (SHPB) test machine. Five commercially available composite resins--namely, two conventional hybrid composites (Filtek Z100, Z100; Filtek Z250, Z250), a packable composite (Filtek P60, P60), a flowable composite (Filtek Flow, FL), and a nanofill composite (Filtek Supreme, SU)--were evaluated. By means of SHPB technique, the dynamic stress-strain curve, storage modulus, and loss tangent of the five dental composites were calculated. All specimens exhibited a nonlinear stress-strain curve in the loading process, which resulted not only from the viscoelasticity--but also from the plasticity--of matrix. In terms of storage modulus, no significant differences were exhibited among the five dental composites (p > 0.05). In terms of loss tangent, Z100 showed a significantly higher value than P60, FL, and SU (p < 0.05). Within the limitations of this investigation using SHPB, it was indicated that the loss tangent increased with increasing filler content.
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Affiliation(s)
- Yasuhiro Tanimoto
- Department of Dental Biomaterials, Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, 2-870-1, Sakaecho Nishi, Matsudo, Chiba 271-8587, Japan.
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Dyer SR, Lassila LVJ, Jokinen M, Vallittu PK. Effect of cross-sectional design on the modulus of elasticity and toughness of fiber-reinforced composite materials. J Prosthet Dent 2005; 94:219-26. [PMID: 16126074 DOI: 10.1016/j.prosdent.2005.06.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STATEMENT OF PROBLEM Many current fabrication protocols for dental fiber-reinforced composites use hand lay-up techniques and technician design input. Little information exists regarding how the manipulation of the cross-sectional design of a prosthesis might affect the modulus of elasticity and toughness. PURPOSE The aim of this study was to determine the effect of simple and complex cross-sectional designs on the modulus of elasticity and toughness of fiber-reinforced composite used for dental prostheses. MATERIAL AND METHODS Two particulate composites (BelleGlass HP and Targis) were reinforced with ultra-high-molecular-weight polyethylene fiber ribbon (Connect), woven E-glass fibers (Vectris Frame), or unidirectional R-glass fibers (Vectris Pontic). A range of fiber positions, orientations, or geometries were incorporated into the rhombic specimens (2 x 2 x 25 mm(3)) to achieve simple and complex experimental cross-sectional designs. The control specimen did not contain fiber reinforcement. Specimens (n=6) were stored 1 week in distilled water at 37 degrees C prior to 3-point load testing to determine the modulus of elasticity (GPa) and toughness (MPa). The data within each main fiber group were subjected to 1-way analysis of variance and a Tukey post hoc test (alpha=.05). Cross-sections of randomly selected test specimens (n=2) were made for scanning electron microscope (SEM) analysis of the fiber distribution. RESULTS The mean modulus of elasticity varied from 8.7 +/- 2.0 GPa (Targis control) to 21.6 +/- 1.4 GPa (2 unidirectional glass fiber reinforcements, 1 each at the tension side and the compression side). Mean toughness varied from 0.07 +/- 0.02 MPa (unidirectional glass fiber positioned at the compression side) as the lowest mean, to 4.53 +/- 0.89 MPa (unidirectional glass fiber positioned at the tension side) as the highest. Significant differences were identified between specimen groups in each main category (all groups P<.001, except modulus of elasticity of the woven E-glass groups, where P=.003). SEM micrographs showed fiber distribution in the cross section of test specimens to correspond with the intended fiber geometry. CONCLUSION The modulus of elasticity of the composite specimens increased when 1 or more glass fiber groups were located at the compression side of the specimen. Toughness was most effectively increased when 1 or more fiber groups were located at the tension side of the specimen.
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Affiliation(s)
- Scott R Dyer
- Department of Restorative Dentistry, Division of Biomaterials and Biomechanics, Oregon Health and Science University, 611 SW Campus Drive, Portland, OR 97239, USA.
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Allen EP, Bayne SC, Brodine AH, Cronin RJ, Donovan TE, Kois JC, Summitt JB. Annual review of selected dental literature: report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry. J Prosthet Dent 2003; 90:50-80. [PMID: 12869974 DOI: 10.1016/s0022-3913(03)00299-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Edward P Allen
- Department of Periodontics, Texas A&M University System, Baylor College of Dentistry, Dallas, Texas, USA.
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