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Jasim ES, Kadhum AS, Hasan I. Keeping the teeth in line: Exploring the necessity of bonded retainers in orthodontics: A narrative review. J Orthod Sci 2024; 13:20. [PMID: 38784083 PMCID: PMC11114454 DOI: 10.4103/jos.jos_159_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/15/2024] [Accepted: 01/28/2024] [Indexed: 05/25/2024] Open
Abstract
In most recent studies, long-term retention after orthodontic treatment has been hypothesized that may be necessary to maintain the stability of the dentition and avoid post-treatment changes. The bonded fixed retainer is characterized by its clinical effectiveness, patient acceptance, and lack of patient complaints as compared with a removable retainer. An electronic database (such as PubMed, PubMed Central, Web of Science, Science Direct, Cochrane Library, Scopus, and ResearchGate) has been collected using specific keywords. Of the 152 articles, only randomized clinical trials that investigated different types of fixed retainers or compared fixed with removable retainers were illustrated in tables and included in this review. The present review has gone some way towards enhancing our understanding of the bonded fixed retainer, types, material, bonding methods, and how to improve its the success rate, besides the importance of new technology in fixed orthodontic retention.
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Affiliation(s)
- Esraa S. Jasim
- Department of Orthodontic, College of Dentistry, University of Baghdad, Iraq
| | - Ammar S. Kadhum
- Department of Orthodontic, College of Dentistry, University of Baghdad, Iraq
| | - Istabrak Hasan
- Department of Prosthetic Dentistry, Preclinical Education and Materials Science, Dental School, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany
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Lone SB, Zeeshan R, Khadim H, Khan MA, Khan AS, Asif A. Synthesis, monomer conversion, and mechanical properties of polylysine based dental composites. J Mech Behav Biomed Mater 2024; 151:106398. [PMID: 38237205 DOI: 10.1016/j.jmbbm.2024.106398] [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: 11/20/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 02/03/2024]
Abstract
OBJECTIVE The aim of this study was to synthesize a new bioactive and antibacterial composite by incorporating reactive calcium phosphate and antibacterial polylysine into a resin matrix and evaluate the effect of these fillers on structural analysis, degree of monomer conversion, mechanical properties, and bioactivity of these newly developed polypropylene based dental composites. METHODOLOGY Stock monomers were prepared by mixing urethane dimethacrylate and polypropylene glycol dimethacrylate and combined with 40 wt% silica to make experimental control (E-C). The other three experimental groups contained a fixed percentage of silica (40 wt%), monocalcium phosphate monohydrate, and β-tri calcium phosphate (5 wt% each) with varying amounts of polylysine (PL). These groups include E-CCP0 (0 wt% PL), E-CCP5 (5 wt% PL) and E-CCP10 (10 wt% PL). The commercial control used was Filtek™ Z250 3M ESPE. The degree of conversion was assessed by using Fourier transform infrared spectroscopy (FTIR). Compressive strength and Vicker's micro hardness testing were evaluated after 24 h of curing the samples. For bioactivity, prepared samples were placed in simulated body fluid for 0, 1, 7, and 28 days and were analyzed using a scanning electron microscope (SEM). SPSS 23 was used to analyze the data and one-way ANOVA and post hoc tukey's test were done, where the significant level was set ≤0.05. RESULTS Group E-C showed better mechanical properties than other experimental and commercial control groups. Group E-C showed the highest degree of conversion (72.72 ± 1.69%) followed by E-CCP0 (72.43 ± 1.47%), Z250 (72.26 ± 1.75%), E-CCP10 (71.07 ± 0.19%), and lowest value was shown by E-CCP5 (68.85 ± 7.23%). In shear bond testing the maximum value was obtained by E-C. The order in decreasing value of bond strength is E-C (8.13 ± 3.5 MPa) > Z250 (2.15 ± 1.1 MPa) > E-CCP10 (2.08 ± 2.1 MPa) > E-CCP5 (0.94 ± 0.8 MPa) > E-CCP0 (0.66 ± 0.2 MPa). In compressive testing, the maximum strength was observed by commercial control i.e., Z250 (210.36 ± 18 MPa) and E-C (206.55 ± 23 MPa), followed by E-CCP0 (108.06 ± 19 MPa), E-CCP5 (94.16 ± 9 MPa), and E-CCP10 (80.80 ± 13 MPa). The maximum number of hardness was shown by E-C (93.04 ± 8.23) followed by E-CCP0 (38.93 ± 9.21) > E-CCP10 (35.21 ± 12.31) > E-CCP5 (34.34 ± 12.49) > Z250 (25 ± 2.61). SEM images showed that the maximum apatite layer as shown by E-CCP10 and the order followed as E-CCP10 > E-CCP5 > E-CCP0 >Z250> E-C. CONCLUSION The experimental formulation showed an optimal degree of conversion with compromised mechanical properties when the polylysine percentage was increased. Apatite layer formation and polylysine at the interface may result in remineralization and ultimately lead to the prevention of secondary caries formation.
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Affiliation(s)
- Saadia Bano Lone
- Department of Dental Materials, Rashid Latif Dental College, Lahore, Pakistan
| | - Rabia Zeeshan
- Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan
| | - Hina Khadim
- Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan
| | - Muhammad Adnan Khan
- Department of Dental Materials, Institute of Basic Medical Sciences, Khyber Medical University Peshawar, Peshawar, Pakistan
| | - Abdul Samad Khan
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Anila Asif
- Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan.
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Mechanical characterization and adhesive properties of a dental adhesive modified with a polymer antibiotic conjugate. J Mech Behav Biomed Mater 2022; 129:105153. [DOI: 10.1016/j.jmbbm.2022.105153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 01/05/2022] [Accepted: 02/27/2022] [Indexed: 11/22/2022]
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Biocompatibility, mechanical, and bonding properties of a dental adhesive modified with antibacterial monomer and cross-linker. Clin Oral Investig 2020; 25:2877-2889. [PMID: 33006665 DOI: 10.1007/s00784-020-03605-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/23/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVES This study investigated the antibacterial, cytotoxicity, and mechanical properties of a dental adhesive modified with quaternary ammonium monomer ((2-acryloyloxyethyl)dimethyldodecylammonium bromide) and cross-linker (bis(2-acryloyloxyethyl)methyldodecylammonium bromide). MATERIALS AND METHODS Monomer (M), cross-linker (C), or a combination of these (M + C) were incorporated into adhesive Adper Single Bond Plus (SB) in 5, 10, or 25% (as wt%). A colony-forming unit and MTT assays were used to evaluate antibacterial properties against Streptococcus mutans and cell viability. Resin-dentin beams (0.9 ± 0.1 mm2) were evaluated for micro-tensile bond strength (μTBS) after 24 h, 6 months, and 3 years. Hourglass specimens were evaluated for ultimate tensile strength (UTS) after 24 h, 1 week, and 6 months. Micro-hardness measurements after softening in ethanol were taken as an indirect assessment of the polymer cross-linking density. Kruskal-Wallis, one-way ANOVA, two-way ANOVA, and Student's t test were used for analysis of the antibacterial, cytotoxicity, μTBS, UTS, and hardness data, all with a significance level of p < 0.05. RESULTS 10%M and 25%M demonstrated a significant reduction in S. mutans relative to SB (p < 0.001). No differences in cytotoxicity were detected for any of the groups. After 6 months, no changes in μTBS were shown for any of the groups. After 3 years, all groups evidenced a significant decrease in μTBS (p < 0.05) except 5%M, 5%C, and 5%M + 5%C. All groups demonstrated either stable or significantly increased UTS after 6 months. Except for the cross-linker groups, a significant decrease in micro-hardness was shown for all groups after softening in ethanol (p < 0.05). CONCLUSIONS A 5-10% of monomer may render the resin antibacterial without a compromise to its mechanical and bonding properties. CLINICAL RELEVANCE Biomodification of a resin adhesive with an antibacterial monomer and cross-linker may help improve the life span of adhesive restorations.
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Hydro-Thermal Fatigue of Polymer Matrix Composite Biomaterials. MATERIALS 2019; 12:ma12223650. [PMID: 31698746 PMCID: PMC6888490 DOI: 10.3390/ma12223650] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 11/03/2019] [Accepted: 11/04/2019] [Indexed: 11/16/2022]
Abstract
This study discusses a quantitative fatigue evaluation of polymer-ceramic composites for dental restorations, i.e., commercial (Filtek Z550) and experimental Ex-nano (G), Ex-flow (G). Their evaluation is based on the following descriptors: mechanical strength, elastic modulus and strain work to fracture. Supposed to reflect factors of environmental degradation conditions, thermal fatigue was simulated with a special computer-controlled device performing algorithms of thermocycling. The specimens intended for the strength test underwent 104 hydro-thermal fatigue cycles. This procedure of thermocycling was preceded by aging, which meant immersing the specimens in artificial saliva at 37 °C for 30 days. The strength tests after aging only and after aging and thermocycles were performed in line with the three-point flexural strength (TFS) test, specified in ISO 4049, and the biaxial flexural strength (BFS) test, specifically piston-on-three-ball in accordance with ISO 6872. Based on the results, it can be stated that composites with higher volume content of inorganic particles after aging only show higher strength than materials with lower filler particle content. For example, the average flexural bending strength of the Ex-flow (G) composite was about 45% lower than the value obtained for the Ex-nano (G) material. The residual strength after thermocycles is significantly lower for the experimental composites, whereas a smaller decrease in strength is recorded for the commercial composites. Decreases in strength were about 4% (Filtek Z550), 43% (Ex-nano (G)), and 29% (Ex-flow (G)) for the BFS test; and about 17% (Filtek Z550), 55% (Ex-nano (G)), 60% (Ex-flow (G)) for the TFS test. The elastic modulus of the experimental composites after only aging is higher (about 42%) than that of the commercial composite, but the elastic modulus of the commercial composite increases significantly after thermocycling. A descriptor known as strain work to fracture turns out to be a good descriptor for evaluating the hydro-thermal fatigue of the tested polymer-ceramic composites.
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Lassila L, Keulemans F, Säilynoja E, Vallittu PK, Garoushi S. Mechanical properties and fracture behavior of flowable fiber reinforced composite restorations. Dent Mater 2018; 34:598-606. [PMID: 29366493 DOI: 10.1016/j.dental.2018.01.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/18/2017] [Accepted: 01/08/2018] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The aim was to evaluate the effect of short glass-fiber/filler particles proportion on fracture toughness (FT) and flexural strength (FS) of an experimental flowable fiber-reinforced composite (Exp-SFRC) with two methacrylate resin formulations. In addition, we wanted to investigate how the fracture-behavior of composite restorations affected by FT values of SFRC-substructure. METHODS Exp-SFRC was prepared by mixing 50wt% of dimethacrylate based resin matrix (bisGMA or UDMA based) to 50wt% of various weight fractions of glass-fiber/particulate filler (0:50, 10:40, 20:30, 30:20, 40:10, 50:0wt%, respectively). FT and FS were determined for each experimental material following standards. Specimens (n=8) were dry stored (37°C for 2 days) before they were tested. Four groups of posterior composite crowns (n=6) composed of different Exp-SFRCs as substructure and surface layer of commercial particulate filler composite were fabricated. Crowns were statically loaded until fracture. Failure modes were visually examined. The results were statistically analysed using ANOVA followed by post hoc Tukey's test. RESULTS ANOVA revealed that ratio of glass-fiber/particulate filler had significant effect (p<0.05) on tested mechanical properties of the Exp-SFRC with both monomer systems. Exp-SFRC (50wt%) had significantly higher FT (2.6MPam1/2) and FS (175.5MPa) (p<0.05) compared to non-reinforced material (1.3MPam1/2, 123MPa). Failure mode analysis of crown restorations revealed that FT value of the substructure directly influenced the failure mode. SIGNIFICANCE This study shows that short glass-fibers can significantly reinforce flowable composite resin and the FT value of SFRC-substructure has prior importance, as it influences the crack arresting mechanism.
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Affiliation(s)
- Lippo Lassila
- Department of Biomaterials Science, Institute of Dentistry, University of Turku, Finland; Turku Clinical Biomaterial Center-TCBC, Institute of Dentistry, University of Turku, Turku, Finland
| | - Filip Keulemans
- Department of Biomaterials Science, Institute of Dentistry, University of Turku, Finland
| | - Eija Säilynoja
- Research Development and Production Department, Stick Tech Ltd-Member of GC Group, Turku, Finland
| | - Pekka K Vallittu
- Department of Biomaterials Science, Institute of Dentistry, University of Turku, Finland; Turku Clinical Biomaterial Center-TCBC, Institute of Dentistry, University of Turku, Turku, Finland; City of Turku Welfare Division, Oral Health Care, Turku, Finland
| | - Sufyan Garoushi
- Department of Biomaterials Science, Institute of Dentistry, University of Turku, Finland; Turku Clinical Biomaterial Center-TCBC, Institute of Dentistry, University of Turku, Turku, Finland.
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Physical characterization of unfilled and nanofilled dental resins: Static versus dynamic mechanical properties. Dent Mater 2016; 32:e185-97. [DOI: 10.1016/j.dental.2016.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 03/04/2016] [Accepted: 06/03/2016] [Indexed: 11/20/2022]
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Hirayama S, Iwai H, Tanimoto Y. Mechanical evaluation of five flowable resin composites by the dynamic micro-indentation method. JOURNAL OF DENTAL BIOMECHANICS 2014; 5:1758736014533983. [PMID: 25342983 PMCID: PMC4206663 DOI: 10.1177/1758736014533983] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 04/05/2014] [Indexed: 11/30/2022]
Abstract
Measurement of the strength of brittle materials, such as resin composites, is extremely difficult. Micro-indentation hardness testing is a convenient way of investigating the mechanical properties of a small volume of material. In this study, the mechanical properties of five commercially available flowable resin composites were investigated by the dynamic micro-indentation method. Additionally, the effects of inorganic-filler content on the dynamic hardness and elastic modulus of flowable composites obtained by this method were investigated. The weight percentages of the inorganic fillers in the resin composites were determined by the ashing technique. The results indicate that the mechanical properties of flowable composites are affected by not only the filler content but also the properties of the resin matrix. In conclusion, the dynamic micro-indentation method is a useful technique for determining the mechanical behavior of dental resin composites as brittle material.
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Affiliation(s)
- Satoshi Hirayama
- Department of Operative Dentistry, School of Dentistry at Matsudo, Nihon University, Matsudo, Japan
| | - Hirotoshi Iwai
- Department of Operative Dentistry, School of Dentistry at Matsudo, Nihon University, Matsudo, Japan
| | - Yasuhiro Tanimoto
- Department of Dental Biomaterials, School of Dentistry at Matsudo, Nihon University, Matsudo, Japan
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Flury S, Lussi A, Hickel R, Ilie N. Light curing through glass ceramics: effect of curing mode on micromechanical properties of dual-curing resin cements. Clin Oral Investig 2013; 18:809-18. [DOI: 10.1007/s00784-013-1051-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 07/05/2013] [Indexed: 10/26/2022]
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LIN J, SUN M, ZHENG Z, SHINYA A, HAN J, LIN H, ZHENG G, SHINYA A. Effects of rotating fatigue on the mechanical properties of microhybrid and nanofiller-containing composites. Dent Mater J 2013; 32:476-83. [DOI: 10.4012/dmj.2012-225] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Wahbi MA, Aalam FA, Fatiny FI, Radwan SA, Eshan IY, Al-Samadani KH. Characterization of heat emission of light-curing units. Saudi Dent J 2012; 24:91-8. [PMID: 23960535 DOI: 10.1016/j.sdentj.2012.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 11/22/2011] [Accepted: 01/31/2012] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES This study was designed to analyze the heat emissions produced by light-curing units (LCUs) of different intensities during their operation. The null hypothesis was that the tested LCUs would show no differences in their temperature rises. METHODS FIVE COMMERCIALLY AVAILABLE LCUS WERE TESTED: a "Flipo" plasma arc, "Cromalux 100" quartz-tungsten-halogen, "L.E. Demetron 1" second-generation light-emitting diode (LED), and "Blue Phase C5" and "UltraLume 5" third-generation LED LCUs. The intensity of each LCU was measured with two radiometers. The temperature rise due to illumination was registered with a type-K thermocouple, which was connected to a computer-based data acquisition system. Temperature changes were recorded in continues 10 and 20 s intervals up to 300 s. RESULTS The Flipo (ARC) light source revealed the highest mean heat emission while the L.E. Demetron 1 LED showing the lowest mean value at 10 and 20 s exposure times. Moreover, Cromalux (QTH) recorded the second highest value for all intervals (12.71, 14.63, 14.60) of heat emission than Blue Phase C5 (LED) (12.25, 13.87, 13.69), interestingly at 20 s illumination for all intervals the highest results (18.15, 19.27, 20.31) were also recorded with Flipo (PAC) LCU, and the lowest (6.71, 5.97, 5.55) with L.E. Demetron 1 LED, while Blue Phase C5 (LED) recorded the second highest value at the 1st and 2nd 20 s intervals (14.12, 11.84, 10.18) of heat emission than Cromalux (QTH) (12.26, 11.43, 10.26). The speed of temperature or heat rise during the 10 and 20 s depends on light intensity of emitted light. However, the QTH LCU was investigated resulted in a higher temperature rise than LED curing units of the same power density. CONCLUSION The PAC curing unit induced a significantly higher heat emission and temperature increase in all periods, and data were statistically different than the other tested groups (p < .05). LED (Blue Phase C5) was not statistically significant (p < .05) (at 10 s) than QTH units, also LED (Blue Phase C5, UltraLume 5) generates obvious heat emission and temperature rises than QTH units (at 20 s) except for those which have lower power density of LED curing units (first generation). Thus, the null hypothesis was rejected.
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Affiliation(s)
- Mohammed A Wahbi
- Conservative Dentistry, Makkah Dental Centre, P.O. Box 3381, Makkah, Saudi Arabia
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Albino LGB, Rodrigues JA, Kawano Y, Cassoni A. Knoop microhardness and FT-Raman evaluation of composite resins: influence of opacity and photoactivation source. Braz Oral Res 2011; 25:267-73. [DOI: 10.1590/s1806-83242011000300013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 03/04/2011] [Indexed: 11/22/2022] Open
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Pick B, Meira JB, Driemeier L, Braga RR. A critical view on biaxial and short-beam uniaxial flexural strength tests applied to resin composites using Weibull, fractographic and finite element analyses. Dent Mater 2010; 26:83-90. [DOI: 10.1016/j.dental.2009.09.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 06/14/2009] [Accepted: 09/04/2009] [Indexed: 11/16/2022]
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Souza ROA, Ozcan M, Michida SMA, de Melo RM, Pavanelli CA, Bottino MA, Soares LES, Martin AA. Conversion degree of indirect resin composites and effect of thermocycling on their physical properties. J Prosthodont 2009; 19:218-25. [PMID: 20040031 DOI: 10.1111/j.1532-849x.2009.00551.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
PURPOSE This study evaluated the degree of conversion (DC) of four indirect resin composites (IRCs) with various compositions processed in different polymerization units and investigated the effect of thermal aging on the flexural strength and Vicker's microhardness. MATERIALS AND METHODS Specimens were prepared from four IRC materials, namely Gr 1: Resilab (Wilcos); Gr2: Sinfony (3M ESPE); Gr3: VITA VMLC (VITA Zahnfabrik); Gr4: VITA Zeta (VITA Zahnfabrik) using special molds for flexural strength test (N = 80, n = 10 per group) (25 x 2 x 2 mm(3), ISO 4049), for Vicker's microhardness test (N = 80, n = 10 per group) (5 x 4 mm(2)) and for DC (N = 10) using FT-Raman Spectroscopy. For both flexural strength and microhardness tests, half of the specimens were randomly stored in distilled water at 37 degrees C for 24 hours (Groups 1 to 4), and the other half (Groups 5 to 8) were subjected to thermocycling (5000 cycles, 5 to 55 +/- 1 degree C, dwell time: 30 seconds). Flexural strength was measured in a universal testing machine (crosshead speed: 0.8 mm/min). Microhardness test was performed at 50 g. The data were analyzed using one-way and two-way ANOVA and Tukey's test (alpha= 0.05). The correlation between flexural strength and microhardness was evaluated with Pearson's correlation test (alpha= 0.05). RESULTS A significant effect for the type of IRC and thermocycling was found (p= 0.001, p= 0.001) on the flexural strength results, but thermocycling did not significantly affect the microhardness results (p= 0.078). The interaction factors were significant for both flexural strength and microhardness parameters (p= 0.001 and 0.002, respectively). Thermocycling decreased the flexural strength of the three IRCs tested significantly (p < 0.05), except for VITA Zeta (106.3 +/- 9.1 to 97.2 +/- 14 MPa) (p > 0.05) when compared with nonthermocycled groups. Microhardness results of only Sinfony were significantly affected by thermocycling (25.1 +/- 2.1 to 31 +/- 3.3 Kg/mm(2)). DC values ranged between 63% and 81%, and were not significantly different between the IRCs (p > 0.05). While a positive correlation was found between flexural strength and microhardness without (r = 0.309) and with thermocycling (r = 0.100) for VITA VMLC, negative correlations were found for Resilab under the same conditions (r =-0.190 and -0.305, respectively) (Pearson's correlation coefficient). CONCLUSION Although all four IRCs presented nonsignificant DC values, flexural strength and microhardness values varied between materials with and without thermocycling.
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Affiliation(s)
- Rodrigo O A Souza
- Department of Dental Materials and Prosthodontics, São Jose dos Campos Dental School, São Paulo State University, São Jose dos Campos, Brazil
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Cassoni A, Ferla JDO, Shibli JA, Kawano Y. Knoop Microhardness and FT-Raman Spectroscopic Evaluation of a Resin-Based Dental Material Light-Cured by an Argon Ion Laser and Halogen Lamp: Anin VitroStudy. Photomed Laser Surg 2008; 26:531-9. [DOI: 10.1089/pho.2007.2212] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Alessandra Cassoni
- Department of Restorative Dentistry, Guarulhos University, Guarulhos, Brazil
| | | | - Jamil Awad Shibli
- Department of Periodontology, Guarulhos University, Guarulhos, Brazil
| | - Yoshio Kawano
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
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Alves EB, Alonso RCB, Correr GM, Correr AB, de Moraes RR, Sinhoreti MAC, Correr-Sobrinho L. Transdental Photo-activation Technique: Hardness and Marginal Adaptation of Composite Restorations Using Different Light Sources. Oper Dent 2008; 33:421-5. [DOI: 10.2341/07-109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
The association of transdental and direct photo-activation of composite restorations might improve marginal adaptation, while not being detrimental to composite hardness.
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Janda R, Roulet JF, Latta M, Kaminsky M, Rüttermann S. Effect of exponential polymerization on color stability of resin-based filling materials. Dent Mater 2006; 23:696-704. [PMID: 16899289 DOI: 10.1016/j.dental.2006.06.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Revised: 03/13/2006] [Accepted: 06/19/2006] [Indexed: 02/08/2023]
Abstract
PURPOSE To investigate the influence of a halogen light curing device used with constant or exponential polymerization mode on the color stability of contemporary resin-based filling materials. MATERIALS AND METHODS Eight samples of Charisma (CH), Durafill (DU), Definite (DE), and Dyract AP (DY) each were light-cured with constant power or with soft-start mode (Translux Energy) for 20, 40 or 60s. The CIE-Lab-values (L(*), a(*), b(*)) were measured prior to and after performing dry aging, water aging or a Suntest (EN ISO 7491) and Delta L-, Delta a-, Delta b-, and Delta E-values were calculated. RESULTS Statistical analysis (GLM and repetition of measures) showed significant changes (p<0.05) of the color values for each material's curing mode and time after each of the aging processes. Four-way ANOVA revealed significant differences (p<0.05) between Delta L-, Delta a-, Delta b-, and Delta E of the materials in dependence on the curing time and mode and aging condition. Exponentially-cured DU was the most color-unstable material after aging in water followed by the 20s exponentially cured DE and CH samples. After the Suntest, DY showed significant bleaching (negative Delta b) and the largest Delta E for all curing times and modes followed by the DE samples. DU and CH were the most color-stable materials in this test. SIGNIFICANCE The extent of discoloration depends on the (a) curing time, (b) curing mode, (c) aging condition, and (d) material. For the constant curing mode, 40s curing time for the exponential 60s seems to be appropriate.
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Affiliation(s)
- R Janda
- Heinrich-Heine-University, Medical Faculty, Centre of Dentistry, Department of Operative and Preventive Dentistry and Endodontics, Moorenstr. 5, Geb. 18.13, D-40225 Düsseldorf, Germany.
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Rodrigues Filho LE, Burger LADS, Kenshima S, Bauer JRDO, Medeiros IS, Muench A. Effect of light-activation methods and water storage on the flexural strength of two composite resins and a compomer. Braz Oral Res 2006; 20:143-7. [PMID: 16878208 DOI: 10.1590/s1806-83242006000200010] [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] [Received: 05/10/2005] [Accepted: 04/27/2006] [Indexed: 11/22/2022] Open
Abstract
The present study evaluated the flexural strength of three composite resins recommended for direct esthetic restorations: a polyacid modified composite (Dyract AP), a unimodal composite resin (Filtek Z250) and a hybrid composite resin (Point 4). The variation factors, apart from the type of composite resin, were the light activation method and the water storage period. The composite resins were light-cured in continuous mode (40 s, 500 mW/cm²) or in ramp mode (0-800 mW/cm² for 10 s followed by 30 s at 800 mW/cm²) and stored for 24 hours or 30 days in distilled water at 37°C. The data were analyzed by ANOVA and Tukey test for multiple comparisons (alpha = 0.05). The composite resin Z250 presented the highest mean flexural strength (166.74 MPa) and Dyract AP presented the lowest one (129.76 MPa). The storage for 30 days decreased the flexural strength in ramp mode (24 h: 156.64 MPa; 30 days: 135.58 MPa). The light activation method alone did not lead to different flexural strength values.
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Obici AC, Sinhoreti MAC, Correr-Sobrinho L, Góes MFD, Consani S. Evaluation of mechanical properties of Z250 composite resin light-cured by different methods. J Appl Oral Sci 2005; 13:393-8. [PMID: 20865226 DOI: 10.1590/s1678-77572005000400015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Accepted: 07/26/2005] [Indexed: 11/21/2022] Open
Abstract
This study evaluated some mechanical parameters of Z250 composite resin using different light-curing methods. Ten specimens were prepared for each mechanical test group with different dimensions according to the test. Light-curing was performed by: a). continuous light (800mW/cm²-40s); b). exponential light (0-800mW/cm²-40s); c). intermittent light (2s-600mW/cm²; 2s without light-80s); d). stepped light (10s-150mW/cm²; 30s-650mW/cm²); e). PAC (1320mW/cm²-3s); f). LED (350mW/cm²-40s). After 24 ± 1 h, the specimens were loaded at a crosshead speed of 0.5 mm/min until fracture. The mechanical properties were calculated and analyzed by ANOVA and Tukey test (5%). The results showed that the highest compressive strength values were found for the continuous, exponential, intermittent and stepped light methods, whereas PAC and LED obtained the lowest values. LED, stepped light, PAC, exponential and continuous light presented the highest values for diametral tensile strength. The intermittent light showed the lowest value, which was significantly lower than the value obtained for LED only. Flexural strength results were not significantly different between all light-curing methods. Finally, the highest modulus of elasticity values were obtained for LED, exponential, continuous and intermittent light, whereas PAC and stepped light showed the lowest values. The mechanical properties were affected by light-curing methods employed.
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Stewardson D, Shortall A, Harrington E, Lumley P. Thermal changes and cure depths associated with a high intensity light activation unit. J Dent 2004; 32:643-51. [DOI: 10.1016/j.jdent.2004.06.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2003] [Revised: 06/23/2004] [Accepted: 06/23/2004] [Indexed: 10/26/2022] Open
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Garcia FCP, Wang L, D'Alpino PHP, Souza JBD, Araújo PAD, Mondelli RFDL. Evaluation of the roughness and mass loss of the flowable composites after simulated toothbrushing abrasion. Braz Oral Res 2004; 18:156-61. [PMID: 15311320 DOI: 10.1590/s1806-83242004000200012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The purpose of this study was to measure mass loss and surface roughness changes of different brands of flowable resin composites after a simulated toothbrushing test. The null hypotheses were that there would be no differences in mass loss and no significant changes in surface roughness after this test and that there would be no correlation between the two variables. The tested materials were Aeliteflo (Bisco), Flow-It (Pentron), Flow-It LF (Pentron), Natural Flow (DFL) and Wave (SDI). Z100 (3M/ESPE) microhybrid and Silux Plus (3M/ESPE) microfilled resin composites were used as control materials. Twelve specimens (5 mm in diameter, 3 mm thick) of each material were prepared according to manufacturers' instructions. Toothbrushing abrasion was performed on all specimens from each of the materials using a simulator. The percentage mass loss and surface roughness were assessed before and after 100,000 brushstrokes, using a Sartorius analytical balance of 0.0001 g accuracy and a Hommel Tester T1000, respectively. The measurements of both properties were statistically compared by paired t-test and Tukey's test (p < 0.05). All materials presented a statistically significant mass loss comparing initial and final values, with the exception of Flow-It LF. However, no difference was revealed when comparing the mass loss of the different tested materials. All materials became rougher and Wave presented statistically higher roughness compared to the other resin composites. Flowable resin composites did not seem to be superior to the control groups, and they can be expected to wear by mass loss and to have an increased roughness of surface after toothbrushing action. The anticipated null hypotheses were partially accepted.
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Laser literature watch. JOURNAL OF CLINICAL LASER MEDICINE & SURGERY 2004; 22:69-75. [PMID: 15117491 DOI: 10.1089/104454704773661010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
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