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Ilie N, Diegelmann J. Impact of ultra-fast (3 s) light-cure on cell toxicity and viscoelastic behavior in a dental resin-based composite with RAFT-mediated polymerization. J Mech Behav Biomed Mater 2021; 124:104810. [PMID: 34500355 DOI: 10.1016/j.jmbbm.2021.104810] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The aim of the study was to determine the effects of ultra-fast (3 s) light-curing on the viscoelastic behaviour at clinically relevant frequencies, and cell toxicity, in a resin-based composite (RBC) with reversible addition-fragmentation-chain transfer (RAFT) mediated polymerization. METHODS Three different protocols were used to cure cylindrical samples (height = 4 mm, ϴ = 5 mm), including ultra-fast (3s) cure with high radiant emittance, 10 s and 20 s cure with moderate radiant emittance. The properties of the light curing device were evaluated in all curing protocols by spectrophotometry up to an exposure distance of 10 mm. The light transmission through the samples was determined in real-time with the same spectrophotometer. Absorbance was calculated as a function of wavelength. The quasi-static (indentation hardness/HIT, indentation modulus/EIT) and viscoelastic (storage modulus/E', loss modulus/E″, loss factor/tan δ) material behavior was determined in an instrumented indentation test with a DMA (Dynamic Mechanical Analysis) module for 10 frequencies (0.5-5 Hz) by profiling the center of the samples in 330 μm steps from top to bottom. Cellular toxicity on human gingival fibroblast (HGF-1) was assessed using a WST-1 colorimetric assay after incubation time of up to 3 months. One and multiple-way analysis of variance (ANOVA) with Tukey honestly significant difference (HSD) post-hoc tests (α = 0.05) were applied. RESULTS The irradiance transmitted through a 4 mm high sample was less than 7% of the incident irradiance, and the absorbance was similar for all curing protocols, showing a decrease with wavelength. Similar quasi-static and viscoelastic parameters were observed regardless of the curing protocol. HIT increased slightly and EIT, E', E″ and tan δ decreased with frequency. Occasionally, slightly higher confidence intervals were observed for the ultra-fast curing group, which were related to a potential accumulation of stress. The curing protocol had no effect on cell viability (p = 0.326) but the eluate age (p < 0.001, ηP2 = 0.879) did. None of the groups showed cell toxicity at any point in time with respect to the corresponding negative control. CONCLUSIONS The ultra-fast curing with high irradiance induced no cell toxicity and an equivalent viscoelastic behavior as with conventional curing protocols in a RAFT-modified RBC.
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Affiliation(s)
- Nicoleta Ilie
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU, Germany.
| | - Julia Diegelmann
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU, Germany
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TEKBAŞ ATAY M, BÜYÜKGÖZE DİNDAR M, OZVEREN N. EFFECT OF DISPOSABLE SHEATHS ON THE VICKERS MICROHARDNESS OF RESIN COMPOSITES. CLINICAL AND EXPERIMENTAL HEALTH SCIENCES 2021. [DOI: 10.33808/clinexphealthsci.752555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Yılmaz B, Bakkal M, Zengin Kurt B. Structural and mechanical analysis of three orthodontic adhesive composites cured with different light units. J Appl Biomater Funct Mater 2021; 18:2280800020901716. [PMID: 32242502 DOI: 10.1177/2280800020901716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To evaluate the effects of three different curing units on the physical and mechanical features of three different orthodontic adhesive resin materials. MATERIAL AND METHODS 45 specimens (5 mm in diameter, and 2 mm in thickness) of each of the three different adhesive composite resin materials (Transbond XT, Grēngloo™ Adhesive and Light Bond Paste) were cured with three different light units (a polywave third generation (Valo), a monowave (DemiUltra), and a second-generation LED (Optima 10)). To quantify degree of conversion (DC), the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy was used in transmission mode (ALPHA FT-IR Spectrometer, Bruker Optics, Germany). Vickers hardness value was recorded under constant load 100 g for 10 s with a microhardness tester (HMV M-1, Shimadzu Corp., Kyoto, Japan). The data were statistically analyzed using Kruskal-Wallis and chi-square tests. The level of significance was considered p < 0.05. RESULTS The highest DC values were obtained as a result of curing with Optima 10. This rate was followed by Demi Ultra and Valo, respectively. Transbond XT samples showed a lower level of conversion than the samples of Light Bond Paste and Grēngloo™ Adhesive. The top surfaces of each material showed higher hardness values than the bottom surfaces (p < 0.05). The Light Bond Paste showed the highest hardness values both on the top and bottom surfaces among the three materials, followed by Grēngloo™ Adhesive. While the hardness values of the top surfaces of the samples cured with Demi Ultra and Valo light units were similar, higher hardness values are recorded with Valo on the bottom surfaces (Valo; 85.200/75.200 (top/bottom) versus Demi Ultra; 86.100/66.000 (top/bottom)). CONCLUSIONS The different DC and the surface hardness properties were recorded for the resin as orthodontic adhesives depending on different light units. Shorter radiation time caused lower DC and surface hardness values.
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Affiliation(s)
- Berza Yılmaz
- Department of Orthodontics, Bezmialem Vakif University, Istanbul, Turkey
| | - Meltem Bakkal
- Department of Pediatric Dentistry, Bezmialem Vakif University, Istanbul, Turkey
| | - Belma Zengin Kurt
- Department of Pharmaceutical Biotechnology, Bezmialem Vakif University, Istanbul, Turkey
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Ilie N, Watts DC. Outcomes of ultra-fast (3 s) photo-cure in a RAFT-modified resin-composite. Dent Mater 2020; 36:570-579. [DOI: 10.1016/j.dental.2020.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 11/28/2022]
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Kim HJ, Bagheri R, Kim YK, Son JS, Kwon TY. Influence of Curing Mode on the Surface Energy and Sorption/Solubility of Dental Self-Adhesive Resin Cements. MATERIALS 2017; 10:ma10020129. [PMID: 28772489 PMCID: PMC5459112 DOI: 10.3390/ma10020129] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 11/21/2022]
Abstract
This study investigated the influence of curing mode (dual- or self-cure) on the surface energy and sorption/solubility of four self-adhesive resin cements (SARCs) and one conventional resin cement. The degree of conversion (DC) and surface energy parameters including degree of hydrophilicity (DH) were determined using Fourier transform infrared spectroscopy and contact angle measurements, respectively (n = 5). Sorption and solubility were assessed by mass gain or loss after storage in distilled water or lactic acid for 60 days (n = 5). A linear regression model was used to correlate between the results (%DC vs. DH and %DC/DH vs. sorption/solubility). For all materials, the dual-curing consistently produced significantly higher %DC values than the self-curing (p < 0.05). Significant negative linear regressions were established between the %DC and DH in both curing modes (p < 0.05). Overall, the SARCs showed higher sorption/solubility values, in particular when immersed in lactic acid, than the conventional resin cement. Linear regression revealed that %DC and DH were negatively and positively correlated with the sorption/solubility values, respectively. Dual-curing of SARCs seems to lower the sorption and/or solubility in comparison with self-curing by increased %DC and occasionally decreased hydrophilicity.
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Affiliation(s)
- Hyun-Jin Kim
- Department of Dental Science, Graduate School, Kyungpook National University, Daegu 41940, Korea.
| | - Rafat Bagheri
- Dental Materials Department and Biomaterials Research Centre, Shiraz University of Medical Sciences, Shiraz 7183643111, Iran.
| | - Young Kyung Kim
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu 41940, Korea.
| | - Jun Sik Son
- Korea Textile Development Institute, Daegu 41842, Korea.
| | - Tae-Yub Kwon
- Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, Daegu 41940, Korea.
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Bahrololoomi Z, Soleimani AA, Jafari N, Varkesh B. Micro-leakage of a Fissure Sealant Cured Using Quartz-tungsten-halogen and Plasma Arc Light Curing Units. J Dent Res Dent Clin Dent Prospects 2015; 8:252-5. [PMID: 25587389 PMCID: PMC4288917 DOI: 10.5681/joddd.2014.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 08/24/2014] [Indexed: 11/17/2022] Open
Abstract
Background and aims. Newer curing units such as plasma arc can polymerize the sealants in much shorter curing times. The aim of this study was to compare the effect of two different curing units on the micro-leakage of a fissure sealant material. Materials and methods. Sixty two extracted premolars without caries were randomly divided into two groups of 31 samples. Occlusal surfaces of all teeth were cleansed. Then, teeth surfaces were etched by 37% phosphoric acid. After rinsing and drying, occlusal surfaces of teeth were sealed by a fissure sealant. The sealant was then cured using either a halogen light curing unit or a plasma arc curing light. After sealing, the teeth were thermocycled for 500 cycles. The teeth were then sectioned and examined for micro-leakage. Statistical analyses were performed with Mann-Whitney test. Results. There was no significant difference between two groups regarding micro-leakage (P = 0.42). Conclusion. Results showed that there was no significant difference between two different curing units. Therefore, plasma arc unit might be a useful alternative for sealant polymerization.
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Affiliation(s)
- Zahra Bahrololoomi
- Associate Professor, Department of Pediatric Dentistry, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Ali Asghar Soleimani
- Assistant Professor, Department of Pediatric Dentistry, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Najmeh Jafari
- Postgraduate Student, Department of Oral Pathology, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Bentolhoda Varkesh
- Postgraduate Student, Department of Pediatric Dentistry, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
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KARAMAN E, GÖNÜLOL N. Does the light source affect the repairability of composite resins? Braz Oral Res 2014; 28:S1806-83242014000100238. [DOI: 10.1590/1807-3107bor-2014.vol28.0027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 03/13/2014] [Indexed: 11/22/2022] Open
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Orçun Zorba Y, Bayındır YZ, Turgut H, Yıldız M. Quality of curing in relation to different light sources by measuring hardness, degree of conversion and depth of cure. ACTA ACUST UNITED AC 2013. [DOI: 10.1179/143289109x12494867167521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- Y. Orçun Zorba
- Department of EndodonticsDentistry Faculty, Kırıkkale University, Kırıkkale, Turkey
| | - Y. Z. Bayındır
- Department of Restorative DentistryDentistry Faculty, Atatürk University, Erzurum, Turkey
| | - H. Turgut
- Department of Restorative DentistryDentistry Faculty, Atatürk University, Erzurum, Turkey
| | - M. Yıldız
- Department of Restorative DentistryDentistry Faculty, Atatürk University, Erzurum, Turkey
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Mirsasaani SS, Ghomi F, Hemati M, Tavasoli T. Measurement of solubility and water sorption of dental nanocomposites light cured by argon laser. IEEE Trans Nanobioscience 2013; 12:41-6. [PMID: 23292826 DOI: 10.1109/tnb.2012.2229468] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Different parameters used for photoactivation process and also composition provide changes in the properties of dental composites. In the present work the effect of different power density of argon laser and filler loading on solubility (SL) and water sorption (WS) of light-cure dental nanocomposites was studied. The resin of nanocomposites was prepared by mixing bisphenol A glycol dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) with a mass ratio of 65/35. 20 wt.% and 25 wt.% of nanosilica fillers with a primary particle size of 10 nm were added to the resin. Camphorquinone (CQ) and DMAEMA were added as photoinitiator system. The nanocomposites were cured by applying the laser beam at the wavelength of 472 nm and power densities of 260 and 340 mW/cm(2) for 40 sec. Solubility and water sorption were then measured according to ISO 4049, which in our case, the maximums were 2.2% and 4.3% at 260 mW/cm(2) and 20% filler, respectively. The minimum solubility (1.2%) and water sorption (3.8%) were achieved for the composite containing 25% filler cured at 340 mW/cm(2). The results confirmed that higher power density and filler loading decreased solubility of unreacted monomers and water sorption and improved physico-mechanical properties of nanocomposites.
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Affiliation(s)
- Seyed Shahabeddin Mirsasaani
- Biomaterials Group, Faculty of Biomedical Engineering (Center of Excellence), Amirkabir University of Technology, Tehran 158754412, Iran.
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Wang K, Yin R, Nie J, Yu Q. Synthesis and characterization of a novel dimethacrylate based on adamantane as possible dental resins. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012. [DOI: 10.1016/j.msec.2012.02.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Yaman BC, Efes BG, Dörter C, Gömeç Y, Erdilek D, Büyükgökçesu S. The effects of halogen and light-emitting diode light curing on the depth of cure and surface microhardness of composite resins. J Conserv Dent 2011; 14:136-9. [PMID: 21814353 PMCID: PMC3146104 DOI: 10.4103/0972-0707.82613] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 01/25/2011] [Accepted: 03/19/2011] [Indexed: 11/20/2022] Open
Abstract
Aim: Light-emitting diode light curing units (LED LCUs) have become more popular than halogen LCUs in routine dental restorative treatment. The aim of the study was to compare the effects of two conventional halogen (Hilux Plus and VIP) and two LED (Elipar FreeLight 2 and Smart Lite) light curing units on the depth of cure and the microhardness of various esthetic restorative materials. Materials and Methods: The curing depth and microhardness of a compomer (Dyract Extra), a resin-modified glass ionomer (Vitremer), a packable composite (Sculpt It), an ormocer (Admira), a hybrid composite (Tetric Ceram), two microhybrid composites (Miris and Clearfil Photo Posterior) and, a nanofil composite (Filtek Supreme) were determined using a scraping method and a hardness tester. A total of 320 samples were prepared using the eight different materials (n = 10 samples for each subgroup). The scraping test was based on ISO 4049:2000. Vicker's microhardness testing was carried out using hardness tester (Zwick 3212). Data were analyzed using one-way analysis of variance (ANOVA), Bonferroni and the Kolmogorov–Smirnov tests. Results: Best microhardness results were obtained with the LED light curing units and Tetric EvoCeram and Filtek Supreme achieved the highest hardness values. The nanofil composite, Filtek Supreme, showed the best curing depth results in all the tested light curing systems. Conclusions: The LEDs were found to be more successful than the halogen units with respect to both curing depth and microhardness properties.
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Affiliation(s)
- Batu Can Yaman
- Department of Operative Dentistry, Faculty of Dentistry, Istanbul University, Capa/Fatih-34093, Istanbul, Turkey
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Cekic-Nagas I, Ergun G. Effect of different light curing methods on mechanical and physical properties of resin-cements polymerized through ceramic discs. J Appl Oral Sci 2011; 19:403-12. [PMID: 21710093 PMCID: PMC4223794 DOI: 10.1590/s1678-77572011005000017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 10/26/2010] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The aim of this study was to compare the polimerization ability of three different light-curing units (quartz tungsten halogen, light-emitting diodes and plasma arc) and their exposure modes (high-intensity and soft-start) by determination of microhardness, water sorption and solubility, and diametral tensile strength of 5 dual-curing resin cements. MATERIAL AND METHODS A total of 720 disc-shaped samples (1 mm height and 5 mm diameter) were prepared from different dual-curing resin cements (Duolink, Nexus, Bifix-QM, Panavia F and RelyX Unicem). Photoactivation was performed by using quartz tungsten halogen (high-power and soft-up modes), light-emitting diode (standard and exponential modes) and plasma arc (normal and ramp-curing modes) curing units through ceramic discs. Then the samples (n=8/per group) were stored dry in the dark at 37°C for 24 h. The Vickers hardness test was performed on the resin cement layer with a microhardness tester (Shimadzu HMV). For sorption and solubility tests; the samples were stored in a desiccator at 37°C and weighed to a constant mass. The samples were weighed both before and after being immersed in deionized water for different periods of time (24 h and 7 days) and being desiccated. The diametral tensile strength of the samples was tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by nonparametric Kruskal Wallis and Mann-Whitney U tests at 5% significance level. RESULTS Resin cement and light-curing unit had significant effects (p<0.05) on microhardness, diametral tensile strength, water solubility and sorption. However, no significant differences (p>0.05) were obtained with different modes of LCUs. CONCLUSION The study indicates that polymerization of resin cements with different light-curing units may result in various polymer structures, and consequently different mechanical and physical properties.
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Affiliation(s)
- Isil Cekic-Nagas
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
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13
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Al-kheraif AA. Effects of curing units and staining solutions on the color susceptibility of a microhybrid composite resin. J Dent Sci 2011. [DOI: 10.1016/j.jds.2011.02.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Iriyama NT, Tango RN, Manetta IP, Sinhoreti MAC, Correr Sobrinho L, Saavedra GDSFA. Effect of light-curing method and indirect veneering materials on the Knoop hardness of a resin cement. Braz Oral Res 2009; 23:108-12. [PMID: 19684942 DOI: 10.1590/s1806-83242009000200003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Accepted: 09/20/2007] [Indexed: 11/22/2022] Open
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Hooshmand T, Mahmoodi N, Keshvad A. Microhardness of a resin cement polymerized by light-emitting diode and halogen lights through ceramic. J Prosthodont 2009; 18:411-6. [PMID: 19486456 DOI: 10.1111/j.1532-849x.2009.00449.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE This study evaluated the curing efficiency of light-emitting diode (LED) and halogen [quartz tungsten halogens (QTH)] lights through ceramic by determining the surface microhardness of a highly filled resin cement. MATERIALS AND METHODS Resin cement specimens (Variolink Ultra; with and without catalyst) (5-mm diameter, 1-mm thick) were condensed in a Teflon mold. They were irradiated through a ceramic disc (IPS Empress 2, diameter 5 mm, thickness 2 mm) by high-power light-curing units as follows: (1) QTH for 40 seconds (continuous), (2) LED for 20 seconds, and (3) LED for 40 seconds (5-second ramp mode). The specimens in control groups were cured under a Mylar strip. Vickers microhardness was measured on the top and bottom surfaces by a microhardness tester. Data were analyzed using analysis of variance (ANOVA) and a post hoc Bonferroni test at a significance level of p < 0.05. RESULTS The mean microhardness values of the top and bottom surfaces for the dual-cured cement polymerized beneath the ceramic by QTH or LED (40 seconds) were significantly higher than that of light-cured cement (p < 0.05). The top and bottom surface microhardness of dual-cured cement polymerized beneath the ceramic did not show a statistically significant difference between the LED and QTH for 40 seconds (p > 0.05). CONCLUSIONS The efficiency of high-power LED light in polymerization of the resin cement used in this study was comparable to the high-power QTH light only with a longer exposure time. A reduced curing time of 20 seconds with high-power LED light for photopolymerizing the dual-cured resin cement under ceramic restorations with a minimum 2-mm thickness is not recommended.
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Affiliation(s)
- Tabassom Hooshmand
- Department of Dental Materials, School of Dentistry/Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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16
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Insufficient cure under the condition of high irradiance and short irradiation time. Dent Mater 2009; 25:283-9. [PMID: 18760834 DOI: 10.1016/j.dental.2008.07.007] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 05/30/2008] [Accepted: 07/18/2008] [Indexed: 11/21/2022]
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DOGAN A, HUBBEZOGLU I, DOGAN OM, BOLAYIR G, DEMIR H. Temperature rise induced by various light curing units through human dentin. Dent Mater J 2009; 28:253-60. [DOI: 10.4012/dmj.28.253] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Rüttermann S, Servos A, Raab WHM, Janda R. In vitro effect of light-emitting diode light polymerization on the color stability of three resin-based restorative materials. Acta Odontol Scand 2008; 66:43-9. [PMID: 18320418 DOI: 10.1080/00016350801918385] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To investigate the color stability of resin-based restorative materials when polymerized with light-emitting diode (LED) curing light in the constant or exponential mode. MATERIAL AND METHODS Eight specimens of Admira (AD), Compoglass F (CO), and Tetric EvoCeram (TE) constantly cured or exponentially cured with a high-powered LED curing light for 10, 20, or 60 s. The CIE-Lab values (L*, a*, b*) were measured prior to and after performing the water storage or color stability test according to EN ISO 7491 (Suntest). RESULTS Statistical analysis showed significant changes in the color values after each of the aging processes, as well as between DeltaL, Deltaa, Deltab, and DeltaE of the materials, which were dependent on curing time, mode, and aging condition (p<0.05). CO performed very well during water storage, but AD and TE exceeded the clinically relevant limit DeltaE=1. After the Suntest and 180 d additional water storage, TE showed the highest mean (SD) DeltaE=4.4 (1.1) to 5.4 (1.9). Although AD and CO performed best in the constant mode, they exceeded DeltaE=1. All materials shifted to more red. CONCLUSIONS The extent of discoloration depended on (a) the curing mode, (b) the curing time, and (c) the aging condition. Not all materials performed clinically acceptably in all tests; TE even showed unacceptable DeltaE>3.3. The optimal curing time was 20 s for both curing modes and all tested materials.
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BAEK CJ, HYUN SH, LEE SK, SEOL HJ, KIM HII, KWON YH. The Effects of Light Intensity and Light-curing Time on the Degree of Polymerization of Dental Composite Resins. Dent Mater J 2008; 27:523-33. [DOI: 10.4012/dmj.27.523] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Tango RN, Sinhoreti MAC, Correr AB, Correr-Sobrinho L, Henriques GEP. Effect of Light-Curing Method and Cement Activation Mode on Resin Cement Knoop Hardness. J Prosthodont 2007; 16:480-4. [PMID: 17760867 DOI: 10.1111/j.1532-849x.2007.00234.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To evaluate the Knoop hardness (KHN) of the resin cement Enforce activated by chemical/physical mode or physical mode solely; light-cured directly or through a 1.5 mm thick ceramic disc (HeraCeram) on shade DD2. MATERIALS AND METHODS Light-curing was carried out using a conventional quartz tungsten halogen light (QTH) (XL2500) for 40 seconds at 700 mW/cm(2); light-emitting diodes (LED) (Ultrablue Is) for 40 seconds at 440 mW/cm(2); and Xenon plasma arc (PAC) (Apollo 95E) for 3 seconds at 1600 mW/cm(2). Bovine incisors had their buccal faces flattened and hybridized. A mold was seated on these surfaces and filled with cement. A disc of the acid-etched and silanized veneering material was seated over this set for light-curing. After dry storage (24 hours at 37 degrees C), specimens (n= 10) were sectioned for KHN measurements performed in a microhardness tester (50 gf load for 15 seconds). Data were submitted to ANOVA and Tukey's test (alpha= 0.05). RESULTS The highest KHN values were obtained with LED, for both dual-cured and light-cured cement. The lowest KHN value was obtained with light-cured PAC. Light-curing with QTH resulted in hardness values similar to PAC in dual-cured groups. CONCLUSIONS Light-curing through HeraCeram can influence resin cement hardness.
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Affiliation(s)
- Rubens Nisie Tango
- Department of Restorative Dentistry, Piracicaba Dental School-UNICAMP, Sao Paulo, Brazil
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Khosroshahi ME, Atai M, Nourbakhsh MS. Photopolymerization of dental resin as restorative material using an argon laser. Lasers Med Sci 2007; 23:399-406. [PMID: 17934770 DOI: 10.1007/s10103-007-0487-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Accepted: 07/13/2007] [Indexed: 10/22/2022]
Abstract
The effect of the 488-nm wavelength of argon laser at different power densities and irradiation times on the degree of conversion (DC), temperature rise, water sorption, solubility, flexural strength, flexural modulus, and microhardness of bisphenole A glycol dimethacrylate and triethylen glycol dimethacrylate with a mass ratio of 75:25 was studied. Camphorquinone and N,N'-dimethyl aminoethyl methacrylate were added to the monomer as a photo initiator system. The DC% of the resin was measured using Fourier transform infrared spectroscopy. The maximum DC% (50%), which was reached in 20 s, and temperature rise because of the reaction (13.5 degrees C) were both higher at 1075 than 700 mW/cm(2). Water sorption and solubility were measured according to ISO4049, which in our case were 23.7 and 2.20 microg/mm(3) at 1075 mW/cm(2), respectively. A flexural modulus of 1.1 GPa and microhardness of 19.6 kg/mm(2) were achieved above the power density. No significant difference was observed (i.e., p>0.05) for water sorption and flexural strength at 700 and 1075 mW/cm(2).
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Affiliation(s)
- M E Khosroshahi
- Faculty of Biomedical Eng, Amirkabir University of Technology, Tehran, Iran.
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Shah S, Roebuck EM, Nugent Z, Deery C. In vitro microleakage of a fissure sealant polymerized by either a quartz tungsten halogen curing light or a plasma arc curing light. Int J Paediatr Dent 2007; 17:371-7. [PMID: 17683327 DOI: 10.1111/j.1365-263x.2007.00825.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND The benefits of using plasma arc curing lights with their shorter curing times in the management of children are potentially great, provided there are no adverse effects. OBJECTIVE The aim of this study was to investigate whether the microleakage of a resin-based sealant is influenced by polymerization with either a conventional quartz tungsten halogen or a plasma arc curing light. DESIGN This study took the form of an in vitro randomized control trial. Seventy extracted human first and second permanent premolars and molars were randomly allocated into two groups. Their occlusal surfaces were sealed with a light-cured fissure sealant using either a quartz tungsten halogen curing light or a plasma arc curing light. The teeth were then sectioned, resulting in four surfaces per tooth, which were examined for microleakage under x 15 magnification with a light microscope. The principal unit of analysis was the tooth (worst section score) and not the section microleakage score. RESULTS No statistical significant difference in microleakage scoring between the two groups was demonstrated. CONCLUSION This study found no difference in the degree of microleakage of fissure sealants polymerized by either light source.
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Affiliation(s)
- Sarah Shah
- Department of Paediatric Dentistry, Royal London Dental Hospital, London, UK
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Shi S, Nie J. Dimethacrylate based on cycloaliphatic epoxide for dental composite. Dent Mater 2007; 24:530-5. [PMID: 17673283 DOI: 10.1016/j.dental.2007.05.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Revised: 11/27/2006] [Accepted: 05/31/2007] [Indexed: 11/21/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the kinetics and mechanical properties of dimethacrylate monomer based on cycloaliphatic epoxide for dental restorative composite. METHODS Dimethacrylate based on cycloaliphatic epoxide (EPCDMA) was copolymeirzed with TEGDMA by varying the curing conditions: monomer composition and light intensity. A real-time near FTIR technique was employed to monitor the double bond conversion and the rate of polymerization. Dynamic mechanical analysis was performed on a dynamic mechanical analyzer, and volume shrinkage of the cured samples was determined by pycnometric method. RESULTS The results of kinetics showed that, two peaks of maximum rate of polymerization (Rpmax) occurred when the amount of TEGDMA was more than 30wt%. Increasing the amount of TEGDMA, the final double bond conversion and polymerization shrinkage both increased, while the glass transition temperature (Tg) decreased. All EPCDMA/TEGDMA mixtures had slightly higher storage modulus at body temperature (37 degrees C). When compared with Bis-GMA/TEGDMA (70/30), the EPCDMA/TEGDMA (70/30) system assumed similar reactivity and volume shrinkage but higher Tg. SIGNIFICANCE EPCDMA had comparable mechanical properties to those of Bis-GMA.
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Affiliation(s)
- Suqing Shi
- Key Laboratory of Biomedical Polymers of Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, PR China
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Janda R, Roulet JF, Latta M, Rüttermann S. Water sorption and solubility of contemporary resin-based filling materials. J Biomed Mater Res B Appl Biomater 2007; 82:545-51. [PMID: 17285606 DOI: 10.1002/jbm.b.30760] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE Evaluation of water sorption and solubility of contemporary resin-based filling materials. METHODS Specimens of Herculite (HE), Point 4 (P4), TetricCeram (TC), Miris (MI), TetricCeram HB (HB), Solitaire 2 (SO), SureFil (SU), Definite (DE), Admira (AD), Dyract AP (DY), Compoglass F (CO), and TetricFlow (TF) were prepared according to ISO 4049. Water sorption and solubility were measured after water storage at 37 degrees C for 7 days. RESULTS Water sorption was HE 14 microg mm(-3), P4 17 microg mm(-3), TC 12 microg mm(-3), MI 13 microg mm(-3), HB 9 microg mm(-3), SO 18 microg mm(-3), SU 9 microg mm(-3), DE 14 microg mm(-3), AD 27 microg mm(-3), DY 19 microg mm(-3), CO 23 microg mm(-3), and TF 19 microg mm(-3). Solubility was HE 3 microg mm(-3), P4 3 microg mm(-3), TC 1 microg mm(-3), MI 0 microg mm(-3), HB 0 microg mm(-3), SO 3 microg mm(-3), SU 0 microg mm(-3), DE 1 microg mm(-3), AD 2 microg mm(-3), DY 4 microg mm(-3), CO -2 microg mm(-3), and TF 1 microg mm(-3). CONCLUSION All materials met the corresponding requirement in ISO 4049. Filler load negatively correlated with water sorption but not with solubility. There was an influence of the resin matrix, too. No significant differences were found between composites, ormocers, and compomers.
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Affiliation(s)
- Ralf Janda
- Medical Faculty, Department of Operative and Preventive Dentistry and Endodontics, Centre of Dentistry, Heinrich-Heine-University, Düsseldorf, Germany
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Janda R, Roulet JF, Latta M, Rüttermann S. The effects of thermocycling on the flexural strength and flexural modulus of modern resin-based filling materials. Dent Mater 2006; 22:1103-8. [PMID: 16406120 DOI: 10.1016/j.dental.2005.09.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 08/17/2005] [Accepted: 09/07/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Evaluation of flexural strengths and flexural moduli of hybrids, packables, ormocers, compomers and flowables prior to, and after, thermocycling. MATERIALS AND METHODS Twenty specimens, size (25 +/- 2) mm x (2 +/- 0.1) mm x (2+/-0.1) mm, of Herculite (HE), Point 4 (P4), TetricCeram (TC), Miris (MI), TetricCeram HB, (HB), Solitaire 2 (SO), Surefil A (SU), Definte (DE), Admira (AD), Dyract AP (DY), Compoglass (CO) and TetricFlow (TF) were made according to ISO 4049. A three-point-bending test was carried out for the first 10 specimens after 24 h water storage at 37 degrees C and for the second 10 specimens after 30-day water storage at 37 degrees C, followed by 5000 thermocycles between +5 and +55 degrees C. For each test series flexural strengths and flexural moduli were calculated. Statistical significance was p < 0.05. RESULTS Flexural strengths of DY and CO missed the 80 MPa limit of ISO 4049 for occlusal fillings prior to and after thermocycling. AD missed it after thermocycling. HE, P4, TC, MI, HB, SO, SU, DE and TF did not significantly differ prior to and after thermocycling. Flexural strength of SO and AD significantly decreased after thermocycling. No change of the flexural moduli could be observed for any of the test materials. Only SU exceeded 10,000 MPa prior to and after thermocycling. SIGNIFICANCE Only DY and CO missed the flexural strength limit of ISO 4049 for occlusal fillings. Only SU exceeded a flexural modulus of 10,000 MPa prior to and after thermocycling.
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Affiliation(s)
- R Janda
- Centre of Dentistry, Heinrich-Heine-University, Düsseldorf, Germany
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Schneider LFJ, Consani S, Ogliari F, Correr AB, Sobrinho LC, Sinhoreti MAC. Effect of time and polymerization cycle on the degree of conversion of a resin composite. Oper Dent 2006; 31:489-95. [PMID: 16924990 DOI: 10.2341/05-81] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this investigation was to verify the influence of 3 light curing units on the degree of conversion, using different irradiation conditions: 1) manufacturers' recommended times of photo-activation, 2) standardizing total energy density among the units and 3) standardizing energy density at the 450-490 nm wavelength range among the units and the effect of these irradiation conditions on the post-cure. Three light curing units were used: halogen, light emitting diodes (LED) and xenon plasma. Seven groups were tested (n=6). Twenty-four hours after the photo-activation procedures, half of the composite specimens were submitted to Fourier Transformed Infrared Spectroscopy analysis. The other half was analyzed after 1 month. The results were submitted to 2-way ANOVA and Tukey's test (5%). Twenty-four hour analysis revealed that the second set of irradiation conditions produced a similar degree of conversion among the LCUs. After 1 month, the conversion values were statistically higher for 20 seconds of halogen exposure (increased from 46.78 to 49.66%), 20 seconds of LED exposure (from 46.20 to 51.15%), 30 seconds of LED exposure (from 48.29% to 50.68%) and 3 seconds of PAC exposure (from 42.57 to 51.39%). The initial degree of conversion and post-cure depended on the photo-activation condition applied.
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Yazici AR, Müftü A, Kugel G, Perry RD. Comparison of Temperature Changes in the Pulp Chamber Induced by Various Light Curing Units, In Vitro. Oper Dent 2006; 31:261-5. [PMID: 16827031 DOI: 10.2341/05-26] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
The thickness of the residual dentin is a critical factor in the reducing thermal transfer to pulp, and this transfer varies with the curing unit used.
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Affiliation(s)
- A Rüya Yazici
- Hacettepe University, Faculty of Dentistry, Department of Conservative Dentistry, Ankara, Turkey.
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Nalcaci A, Kucukesmen C, Uludag B. Effect of high-powered LED polymerization on the shear bond strength of a light-polymerized resin luting agent to ceramic and dentin. J Prosthet Dent 2005; 94:140-5. [PMID: 16046968 DOI: 10.1016/j.prosdent.2005.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STATEMENT OF PROBLEM A newly introduced high-powered light-emitting diode (LED) light-polymerization unit with various polymerization modes is purported to polymerize dental resins more quickly than standard units. However, there is insufficient information about the effects of this type of light source and its polymerization modes on resin luting agents (RLAs). PURPOSE This in vitro study evaluated the effects of different modes of a high-powered LED polymerization unit on the shear bond strength of a light-polymerized RLA to ceramic and dentin. MATERIAL AND METHODS Sixty ceramic cylinders (3 x 3 mm) were fabricated from a heat-pressed ceramic (IPS Empress 2). Specimen surfaces were abraded using 600-grit silicon carbide paper and airborne-particle abraded with 50-mum desiccant alumina particles, cleaned ultrasonically, etched using hydrofluoric acid, and treated with a silane coupling agent (Ceramic primer). Sixty noncarious, freshly extracted, permanent human molar teeth were embedded in autopolymerizing acrylic resin, and their dentin surfaces were wet-ground using a grinding and polishing machine fitted with 180-grit abrasive disks. The ground dentin surfaces were then etched with 37% phosphoric acid gel, and an adhesive agent (Single Bond) was applied. Ceramic specimens (n = 15) were bonded to dentin surfaces with a dual-initiated RLA (Rely-X ARC) and individually polymerized by 1 of 4 different modes, as follows: Halogen standard mode (Control) (600 mW/cm2 for 40 seconds); high-powered LED fast mode (1100 mW/cm2 for 10 seconds); high-powered LED pulse mode (1100 mW/cm2 for 10 seconds); and high-powered LED exponential mode (1100 mW/cm2 for 20 seconds). Cemented specimens were subjected to shear loading until fracture using a universal testing machine. A stereomicroscope (x25) was used to identify the mode of fracture. Bond strength (MPa) data were analyzed using 1-way analysis of variance and the Tukey HSD test (alpha = .05). RESULTS Specimens polymerized using halogen standard mode (23.9 +/- 1.3 MPa) and LED exponential mode (23.0 +/- 1.1 MPa) had significantly higher ( P < .001) mean shear bond strengths compared with both LED fast (15.1 +/- 1.3 MPa) and pulse (14.6 +/- 1.3 MPa) modes. The Tukey HSD tests showed no significant differences in shear bond strength between specimens polymerized using high-powered LED exponential mode and halogen standard mode. Most failures were adhesive failures at the dentin-RLA interface or the RLA-ceramic interface in specimens polymerized using high-powered LED fast or pulse modes. CONCLUSION Within the limitations of this study, the shear bond strength of an RLA to ceramic and dentin was found to be similar when polymerized using halogen light in standard mode and high-powered LED light in exponential mode, whereas shear bond strength was significantly lower when polymerized using LED in fast or pulse mode.
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Affiliation(s)
- Adil Nalcaci
- Faculty of Dentistry, Ankara University, Ankara, Turkey.
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Santos MJMC, Souza Júnior MHDSE, Santos Júnior GC, El-Mowafy O, Chedid Cavalcanti AP, Neme CF. Influence of light intensity and curing cycle on microleakage of Class V composite resin restorations. J Appl Oral Sci 2005; 13:193-7. [PMID: 20924548 DOI: 10.1590/s1678-77572005000200019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to determine the effect of a softstart polymerization method from Quartz-Tungsten-Halogen (QTH) and Plasma Arc (PAC) curing units on microleakage of Class V composite resin restorations with dentin cavosurface margins. Seventy-five bovine incisors received standardized class V cavities in all dentin margins. Teeth were divided into 5 equal groups according to the curing cycle. The cavities were incrementally restored with a composite resin (Single Bond/Z-100, 3M). Light curing was applied as follows: Group I: PAC light continuous-cycle curing at 1600 mW/cm² for 3s; Group II: PAC light step-cycle curing (2s at 800 mW/cm² then 4s at 1600 mW/cm²); Group III: QTH light continuous-cycle curing at 400 mW/cm² for 40s; Group IV: QTH light ramp-cycle curing (from 100 to 600 mW/cm² in 15s followed by 25s at 600 mW/cm²); Group V: QTH light pulse-delay curing (200 mW/cm² for 3s followed by 3 min delay then 600 mW/cm² for 30s). Teeth were stored in distilled water at 37ºC for 30 days and then subjected to thermocycling for 500 cycles at 5 and 55ºC. Root apices were sealed and teeth coated with nail varnish before they were immersed in 0.5% fuchsine red dye solution. Teeth were then sectioned and slices were scanned with a computer scanner to determine the area of dye leakage using a computer program (Image Tools). Images of tooth slices were also visually examined under magnification and dye penetration along the tooth/restoration interface was scored. Significant differences in the degree of dye penetration and leakage were detected between groups (p<.05). Groups I and II had significantly higher values of dye penetration and leakage than groups III, IV and V. In conclusion, the use of PAC light curing in a continuous or step cycle modes resulted in increased microleakage of Class V resin composite restorations compared with medium intensity QTH light curing. Pulse, ramp and continuous-cycle curing modes with QTH light resulted in similar degrees of microleakage.
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