The Effect of the Light Intensity and Light Distances of LED and QTH Curing Devices on the Hardness of Two Light-Cured Nano-Resin Composites

Pnina Segal, Diva Lugassy, Eitan Mijiritsky, Michal Dekel, Ariel Ben-Amar, Zeev Ormianer, Shlomo Matalon

Department of Oral Rehabilitation, School of Dental Medicine, Tel Aviv University, Tel-Aviv, Israel.

DOI: 10.4236/msa.2015.611106                

Abstract

Background: Effective polymerization of the composite resin is essential to obtain long term clinical success and has a great importance obtaining improved mechanical properties. The purpose of this study was to measure the effect of the light intensity of LED and QTH curing devices in relation to the light distances, on the hardness (KHN) of two light cure nano-resin composite. Material and Methods: The top and bottom surfaces of the two nanofill composite specimens were evaluated. Two LED and two QTH light curing devices were used at nine different distances. Light intensity was measured with two radiometers placed at these same distances from the curing tip. 360 pvc dies were prepared with circular cavity 3 mm in diameter and 2 mm thick. The tested materials were placed in each cavity. The different light curing distances were standardized by adding pvc spacers dies at different height matching the different distances. Top and bottom surface microhardness were evaluated with a Micro Hardness Tester in knoop hardness numbers (Kg/mm²). Data were statistically analyzed using: Three-way ANOVA, Tukey and Pearsons test. Results: It was revealed that there was a statistically significant difference in microhardness between the composites (p < 0.001), between the nine distances (p < 0.001) and between the four light curing devices (p < 0.001). Increasing the distance of the light source from composite resin, the light intensity and the microhardness values at the top and bottom surface decrease. LED light curing devices produced a greater microhardness results at the bottom surface of the specimens. The Filtek Ultimate nanocomposite (3 m) showed highest microhardness values on the top and bottom surfaces, polymerized with all four curing devices and all nine distances compared to Empress Direct nano composite (Ivoclar vivadent). Clinical significant: Even with high power LED curing light, the distance between the tip of the light source and the restoration surface should be as close as possible. In this study, Filtek Ultimate showed better results (highest microhardness values) than Empress Direct.

Keywords

Light-Curing Devices, Nano-Filled Resin Composites, Microhardness

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Mosner, N. and Salz, U. (2001) New Developments of Polymeric Dental Composites. Progress in Polymer Science, 26, 535-576. http://dx.doi.org/10.1016/S0079-6700(01)00005-3
[2]	Bowen, R.L. and Washington, D.C. (1963) Properties of a Silica-Reinforced Polymer for Dental Restorations. The Journal of the American Dental Association, 66, 57-64. http://dx.doi.org/10.14219/jada.archive.1963.0010
[3]	Cramer, N.B., Stansbury, J.W. and Bowman, C.N. (2011) Recent Advances and Developments in Composite Dental Restorative Materials. Journal of Dental Research, 90, 402-416. http://dx.doi.org/10.1177/0022034510381263
[4]	Rueggeberg, F.A. (2011) State of the Art: Dental Photocuring—A Review. Dental Materials, 27, 39-52. http://dx.doi.org/10.1016/j.dental.2010.10.021
[5]	Malhotra, N. and Mala, K. (2011) Light Curing Considerations for Resin Based Composite Materials: A review. Part 1. Compendium, 31, 498-506.
[6]	Ruyter, I.E. and Oysaed, H. (1982) Conversion in Different Depths of Ultraviolet and Visible Light Activated Composite Materials. Acta Odontologica Scandinavica, 40, 179-192. http://dx.doi.org/10.3109/00016358209012726
[7]	Wayne, D.C. (1980) Factors Affecting the Depth of Cure of UV-Polymerized Composites. Journal of Dental Research, 59, 800-808. http://dx.doi.org/10.1177/00220345800590050901
[8]	Lippke, J.A., Gordon, L.K., Brash, D.E. and Haseltine, W.A. (1981) Distribution of UV Light-Induced Damage in a Defined Sequence of Human DNA: Detection of Alkaline Sensitive Lesion at Pyrimidine Nucleoside-Cytidine Sequences. Proceedings of the National Academy of Sciences, 78, 3388-3392. http://dx.doi.org/10.1073/pnas.78.6.3388
[9]	Dental Product Spotlight (2002) Visible Light Curing. Journal of the American Dental Association, 133, 1430-1431.
[10]	Garcia, A.H., Lozano, M.A., Vila, J.C., Escribano, A.B. and Galve, P.F. (2006) Composite Resins. A Review of the Materials and Clinical Indications. Medicina Oral Patologia Oral y Cirugia Bucal, 11, 215-220.
[11]	Roberson, T. (2006) Art and Science of Operative Dentistry. 5th Edition, Mosby, St. Louis, 205-210.
[12]	Correr, A.B., Coehlho Sinhoreti, M.A., Sobrinho, L.C., Tango, R.N., Jochims, L.F. and Consani, S. (2005) Effect of the Increase of Energy Dentistry on Knoop Hardness of Dental Composites Light-Cured by Conventional QTH, LED and Xenon Plasma Arc. Brazilian Dental Journal, 16, 218-224. http://dx.doi.org/10.1590/S0103-64402005000300009
[13]	Kramer, N., Lohbauer, U., Godoy, F.G. and Frankenberger, R. (2008) Light Curing of Resin-Based Composites in the LED Era. American Journal of Dentistry, 21, 135-142.
[14]	Caughman, W.F., Rueggeberg, F.A. and Curtis, J.W. (1995) Clinical Guidelines for Photocuring Restorative Resins. The Journal of the American Dental Association, 126, 1280-1282. http://dx.doi.org/10.14219/jada.archive.1995.0364
[15]	Chang, J.B., Seok-Hee, H., Sang, K.L., Hyo-Joung, S., Hyung, K. and Yong Hoom, K. (2008) The Effect of Light Intensity and Light-Curing Time on the Degree of Polymerization of Dental Composite Resins. Dental Materials Journal, 27, 523-533. http://dx.doi.org/10.4012/dmj.27.523
[16]	Yoon, T.H., Lee, Y.K., Lim, B.S. and Kim, C.W. (2002) Degree of Polymerization of Resin Composite by Different Light Source. Journal of Oral Rehabilitation, 29, 1165-1173. http://dx.doi.org/10.1046/j.1365-2842.2002.00970.x
[17]	Mills, R.W., Jandt, K.D. and Ashworth, S.H. (1993) Dental Composite Depth of Cure with Halogen and Blue Light Emitting Diode Technology. British Dental Journal, 186, 388-391.
[18]	Pires, J.A.F., Cvitko, E., Denehy, G.E. and Swift, E.J. (1993) Effects of Curing Tip Distance on Light Intensity and Composite Resin Microhardness. Quintessence International, 24, 517-521.
[19]	Pilo, A., Oelgisser, D. and Cardash, H.S. (1999) Survey of Output Intensity and Potential for Depth of Cure among Light-Curing Units in Clinical Use. Journal of Dentistry, 27, 235-241. http://dx.doi.org/10.1016/S0300-5712(98)00052-9
[20]	Ceballos, L., Fuentes, M.V., Tafalla, H., Martinez, A., Flores, J. and Rodriguez, J. (2009) Curing Effectiveness of Resin Composites at Different Exposure Times Using LED and Halogen Units. Medicina Oral Patologia Oral y Cirugia Bucal, 14, E51-E56.
[21]	Leonard, D.L., Charlton, D.G., Roberts, H.W. and Cohen, M.E. (2002) Polymerization Efficiency of Led Curing Lights. Journal of Esthetic and Restorative Dentistry, 14, 286-295. http://dx.doi.org/10.1111/j.1708-8240.2002.tb00524.x
[22]	Corciolani, G., Vichi, A., Davidson, C.L. and Ferrari, M. (2008) The Influence of Tip Geometry and Distance on Light Curing Efficacy. Operative Dentistry, 33, 325-331. http://dx.doi.org/10.2341/07-94
[23]	Rode, K.M., Kawano, Y. and Turbino, M.L. (2007) Evaluation of Curing Light Distance on Resin Composite Microhardness and Polymerization. Operative Dentistry, 32, 571-578. http://dx.doi.org/10.2341/06-163
[24]	Aguiar, F.H.B., Lazzari, C.R., Lime, D.A.N.L., Ambrosano, G.M.B. and Lovadino, J.R. (2005) Effect of Light Curing Tip Distance and Resin Shade on Microhardness of a Hybrid Resin Composite. Brazilian Oral Research, 19, 302-306. http://dx.doi.org/10.1590/S1806-83242005000400012
[25]	Thome, T., Steagall Jr., W., Arlene, T., Braga, S.R.M. and Turbino, M.L. (2007) Influence of the Distance of the Curing Light Source and Composite Shade on Hardness of Two Composites. Journal of Applied Oral Science, 15, 486-492. http://dx.doi.org/10.1590/S1678-77572007000600006
[26]	Nagas, I.C., Egilmez, F. and Ergun, G. (2010) The Effect of Irradiation Distance on Microhardness of Resin Composites Cured with Different Light Curing Units. European Journal of Dentistry, 4, 440-446.
[27]	Correr, L., Lima, A.A., Consani, S., Coelho Sinhoreti, M.A. and Knowles, J.A. (2000) Influence of Curing Tip Distance on Composite Knoop Hardness Values. Brazilian Dental Journal, 11, 11-17.
[28]	Li, Y., Swartz, M.L., Philips, R.W., Moore, B.K. and Roberts, T.A. (1985) Effect of Filler Content and Size on Properties of Composites. Journal of Dental Research, 64, 1396-1401. http://dx.doi.org/10.1177/00220345850640121501
[29]	Rueggeberg, F.A., Caughman, W.F. and Comer, R.W. (1996) The Effect of Autoclaving on Energy Transmission through Light-Curing Tips. The Journal of the American Dental Association, 127, 1183-1187. http://dx.doi.org/10.14219/jada.archive.1996.0409
[30]	Price, B.T.R., Corey, A.F. and Pantelis, A. (2003) Evaluation of a Second-Generation LED Curing Light. Journal of the Canadian Dental Association, 69, 666a-666h.
[31]	Roberson, T. (2006) Art and Science of Operative Dentistry. 5th Edition, Mosby, St. Louis, 500-502.
[32]	Ferracane, J.L. (1995) Current Trends in Dental Composites. Critical Reviews in Oral Biology & Medicine, 6, 302-318. http://dx.doi.org/10.1177/10454411950060040301
[33]	Dijken, J.W.V. (1986) A Clinical Evaluation of Anterior Conventional, Microfiller, and Hybrid Composite Resin Fillings. Acta Odontologica Scandinavica, 44, 357-367. http://dx.doi.org/10.3109/00016358609094346
[34]	Yap, A., Tan, C.H. and Chung, S.M. (2004) Wear Behavior of New Composite Restoratives. Operative Dentistry, 29, 269-274.
[35]	Topcu, F.T., Erdemer, U., Sahinkesen, G., Yildiz, E., Uslan, I. and Acikel, C. (2010) Evaluation of Microhardness, Surface Roughness and Wear Behavior of Different Types of Resin Composites Polymerized with Two Different Light Sources. Journal of Biomedical Materials Research, 92, 470-478.
[36]	Mitra, S.B., Wu, D. and Holmes, B.N. (2003) An Application of Nanotechnology in Advanced Dental Materials. The Journal of the American Dental Association, 134, 1382-1390. http://dx.doi.org/10.14219/jada.archive.2003.0054
[37]	Asmussen, E. (1982) Restorative Resins: Hardness and Strength vs. Quantity of Remaining Double Bonds. European Journal of Oral Sciences, 90, 484-489. http://dx.doi.org/10.1111/j.1600-0722.1982.tb00766.x
[38]	Chung, K.H. and Greener, E.H. (1990) Correlation between Degree of Conversion, Filler Concentration and Mechanical Properties of Posterior Composite Resins. Journal of Oral Rehabilitation, 17, 487-494. http://dx.doi.org/10.1111/j.1365-2842.1990.tb01419.x
[39]	Ferracane, J.L. (1985) Correlation between Hardness and Degree of Conversion during the Setting Reaction of Unfilled Dental Restorative Resins. Dental Materials, 1, 11-14. http://dx.doi.org/10.1016/S0109-5641(85)80058-0
[40]	Wang, L., Dalpino, P.H.P., Lopes, L.G. and Pereira, J.C. (2003) Mechanical Properties of Dental Restorative Materials Relative Contribution of Laboratory Tests. Journal of Applied Oral Science, 11, 162-167. http://dx.doi.org/10.1590/S1678-77572003000300002
[41]	Rode, K.M., Kawano, Y. and Turbino, M.L. (2007) Evaluation of Curing Light Distance on Resin Composite Microhardness and Polymerization. Operative Dentistry, 32, 571-578. http://dx.doi.org/10.2341/06-163
[42]	Hansen, E.K. and Asmussen, E. (1997) Visible Light Curing Units: Correlation between Depth of Cure and Distance between Exit Window and Resin Surface. Acta Odontologia, 55, 162-166. http://dx.doi.org/10.3109/00016359709115410
[43]	Malhotra, N. and Mala, K. (2010) Light-Curing Considerations for Resin-Based Composite Materials: A Review Part 2. Compendium, 31, 584-592.
[44]	Phillips, R.W. (1982) Skinner’s Science of Dental Materials. 8th Edition, Saunders, Philadelphia, 230.
[45]	Cook, W.D. (1986) Curing Efficiency and Ocular Hazards of Dental Photopolymerization Sources. Biomaterials, 7, 449-454. http://dx.doi.org/10.1016/0142-9612(86)90033-5
[46]	Barghi, N., Berry, T. and Hatton, C. (1994) Evaluating Intensity Output of Curing Lights in Private Dental Offices. The Journal of the American Dental Association, 125, 992-996. http://dx.doi.org/10.14219/jada.archive.1994.0204
[47]	Ashaafi, M.M., Maawadh, A.M. and Qahtani, M.Q. (2011) Evaluation of Light Intensity Output of QTH and LED Curing Devices in Various Governmental Health Institutions. Operative Dentistry, 36, 356-361. http://dx.doi.org/10.2341/10-247-O
[48]	Mousavinasab, S.M. and Meyers, L. (2011) Comparison of Depth of Cure, Hardness and Heat Generation of LED and High Intensity QTH Light Sources. European Journal of Dentistry, 5, 299-304.
[49]	Yoon, T.H., Lee, Y.K., Lim, B.S. and Kim, C.W. (2002) Degree of Polymerization of Resin Composites by Different light Sources. Journal of Oral Rehabilitation, 29, 1165-1173. http://dx.doi.org/10.1046/j.1365-2842.2002.00970.x
[50]	Uhl, A., Sigusch, B.W. and Jandt, K.D. (2004) Second Generation LEDs for the Polymerization of Oral Biomaterials. Dental Materials, 20, 80-87. http://dx.doi.org/10.1016/S0109-5641(03)00095-2
[51]	Price, R.B.T., Corey, A.F. and Andreou, P. (2005) Knop Hardness of Ten Resin Composites Irradiated with High-Power LED and Quartz-Tungsten-Halogen Lights. Biomaterials, 26, 2631-2641. http://dx.doi.org/10.1016/j.biomaterials.2004.06.050
[52]	Mota, E.G., Weiss, A., Sphor, A.M., Oshima, H.M.S. and Carvalho, L.M.N. (2011) Relationship between Filler Content and Selected Mechanical Properties of Six Microhybrid Composites. Revista Odonto Ciência, 26, 151-155. http://dx.doi.org/10.1590/S1980-65232011000200010
[53]	Craig, R.G. (2006) Restorative Dental Materials. 12th Edition, Mosby, St Louis, 190-209.
[54]	Mota, E.G., Oshima, H.M.S., Burnett, L.H., Pires, L.A.G. and Rosa, R.S. (2006) Evaluation of Diametral Tensile Strength and Knoop Microhardness of Five Nanofilled Composites in Dentin and Enamel Shades. Stomatologija, 8, 67-69.