A Comparison of the Bleaching Effectiveness of Chlorine Dioxide and Hydrogen Peroxide on Dental Composite

Braz Dent J Brazilian Dental Journal Braz. Dent. J. 0103-6440 Fundação Odontológica de Ribeirão Preto Este estudo foi realizado para verificar se resinas compostas podem ser clareadas com uso do dióxido de cloro, em comparação com peróxido de hidrogênio. Foram preparados discos com resina restauradora Filtek Z350 3M ESPE (n=40), com dimensões 5 mm de diâmetro × 2 mm de espessura. Os discos foram divididos em 4 grupos de 10 discos cada. A avaliação da cor foi realizada por meio do CIEDE2000. Os discos foram manchados com soluções de café, chá, vinho e água destilada (controle) por 5 h diárias durante 14 dias. A avaliação da cor foi repetida nos discos manchados e seguida por clareamento de 5 discos de cada grupo, utilizando dióxido de cloro ou peróxido de hidrogênio pela técnica de consultório. Finalmente, uma última avaliação da cor foi realizada e as técnicas comparadas estatisticamente. DE2000 após o clareamento foi muito próxima ao baseline, para ambos os agentes clareadores, embora o dióxido de cloro tenha mostrado melhores resultados do que o peróxido de hidrogênio. Após o manchamento, houve uma descoloração clinicamente significativa (ΔE2000≥3,43) para os grupos de chá, café e vinho, sendo que o clareamento (ΔE2000) foi melhor obtido com o grupo do vinho, em comparação com chá e café. No geral, o grupo controle (água destilada) teve a menor mudança de cor nos três intervalos. Após o clareamento, a cor em todos os espécimes voltou próxima ao baseline. As diferenças de cor entre o clareamento e o baseline foram inferiores a 3,43 para todos os grupos. Os resultados indicam que o dióxido de cloro é ligeiramente superior ao peróxido de hidrogênio no clareamento de resinas compostas, mantendo a cor próxima à escala do baseline. Introduction Composite resin restorations have been widely used since their introduction due to their excellent esthetic properties. However, a major disadvantage is their discoloration after prolonged exposure to the oral environment, leading to their replacement due to unacceptable color matching (1). Composite resin restorations have a tendency to stain over long-term exposure to several beverages and food materials (2). The typical commonly consumed beverages, which can cause staining, are coffee (3), tea (2), wine (3) and carbonated drinks (4). Replacement of the restoration following discoloration can be avoided by bleaching3, which is more convenient for the dentist as well as more economical for the patient in terms of both time and money. Bleaching can be performed using a variety of bleaching agents and hydrogen peroxide is considered the best, but has shown to have deleterious effects on the properties of composite. Therefore, a comparative study was carried out to assess the effectiveness of bleaching agents through color changes obtained with chlorine dioxide, which is a very popular industrial bleaching agent (5), and hydrogen peroxide, which is the most widely used dental bleaching agent (6). This study aimed to explore chlorine dioxide as a possible alternative to hydrogen peroxide. Material and Methods Composite Selection and Disc Preparation The chosen composite was 3M ESPE Filtek Z350 Universal Restorative, which is a widely used visible light-activated direct restorative nanocomposite designed for anterior and posterior restorations (3M ESPE, St. Paul, MN, USA). The composite resin was injected into stainless steel molds (5 mm diameter x 2 mm thickness) and covered by a glass plate with a Mylar strip. Finger pressure was applied to the covering glass plate to expel excess materials and create a smooth surface. The composite resins were then polymerized in a LED-curing unit (with a 430-480 nm wavelength range) for 40 s to allow thorough polymerization from both sides. The discs were removed from the molds and stored in de-ionized water for a day in an incubator maintained at 37 ºC to allow thorough leaching of any non-polymerized resins, establishing equilibrium in water uptake. The polished discs were then stored in de-ionized water for 24 h before use. A total of 40 discs, 10 in each group, were prepared. Baseline Color Assessment The color of the polished composite discs was assessed according to the Commission Internationale de l'Eclairege (CIE) Delta E 2000 (CIEDE2000) color space using an Eye1 spectrophotometer (X-rite, Grand Rapids, MI, USA). The CIEDE2000 formula was developed by members of the CIE Technical Committee, providing an improved procedure for the computation of industrial color differences (7). Where ΔE00 is the change in color; RT is a hue rotation term; ΔL, ΔC, and ΔH are the compensation differences for neutral colors (primed values; L,C,H); SL is the compensation for lightness; SC is the compensation for chroma; SH is the compensation for hue; and kL, kC, and kH are constants and usually unity. The diameter of the discs exactly coincided with the diameter of the reflectance handle aperture of the spectrophotometer. A mold was prepared and an outline of the position of the reflectance arm was traced over it, in order to place discs in an identical manner every time, thus avoiding the error due to positioning. Each sample with the side that was exposed for color assessment, was kept a note of and at every interval, the same side of the same sample was assessed against the previous readings. Staining Beverage Preparation, the Staining Process and Color Assessment The dietary colorants used in this study were common beverages, which may cause staining of composite resin surfaces with their natural colors. Three different beverages were used in this experiment: coffee (Nescafé Sunrise Coffee-Chicory mix, Nestlé, Gurgaon, India), tea (Brooke Bond Taj Mahal; Hindustan Unilever Limited, Mumbai, India), and red wine (Raya red wine, Nandi Hills; Grover Vineyards Limited, Bangalore, India). Coffee was prepared by boiling 1.3 g of coffee from a sachet in 100 mL of water for two minutes. Tea was prepared by immersing a 2 g tea bag in 100 mL of boiling water. The wine was directly poured into the test tubes. The samples were kept in incubators for 5 h, after which they were washed with distilled water, immersed in distilled water, and kept in the incubators at 37 ºC. This was carried out for 14 days with fresh solutions of beverages each day. A control group with distilled water was also kept for consideration. Finally, the samples were washed and kept in distilled water for a day and color assessment was performed prior to bleaching, as mentioned above. Bleaching and Post-Bleaching Color Assessment Samples were bleached following the initial color assessment. The hydrogen peroxide-based system was Opalescence Boost 40% concentration (Ultradent Products, Inc. South Jordan, UT, USA) while the chlorine dioxide-based system was DioxiWhite Pro Teeth Whitening System with DioxiCare 500-750 ppm/0.050-0.075% concentration; (Frontier Pharma, Long Island, NY, USA). Bleaching was performed as per the manufacturer's instructions. Opalescence Boost 40% is a red gel supplied in two separate syringes, which were mixed and applied with a mixing tip for three cycles of 15 min each. The DioxiWhite in-office bleaching agent gel was mixed in a closed container to keep the concentration of chlorine dioxide constant. Application was repeated seven times for 5 min each time, after which bleaching gel was changed. Polymerizing light was used for chlorine dioxide. Each sample was individually bleached. After this, all the samples were assessed for color changes on the same side as previously described. Statistical Analysis A limit of DE2000 of 3.43 was interpreted as a clinically acceptable difference in this study, which is equivalent to the conventional clinically significant value of 3.3 ΔE*ab (8,9,10) and was calculated by the help of an automatic calculating computer program available at http://www.boscarol.com/DeltaE.html. Data was entered in an MS Excel sheet and analyzed using the Statistical Package for Social Sciences (SPSS version 16). The independent-sample t-test was used to analyze the significance of results between hydrogen peroxide and chlorine dioxide. One-way ANOVA test was used to analyze the effect of the bleaching agents among the different stains. A p value of <0.05 was used as a cut-off level for statistical significance. Results Mean values and significant differences (SDs) of ∆E2000 for intervals of staining and baseline, bleaching and baseline, and bleaching and staining are listed in Table 1. After staining, there was a clinically significant discoloration (∆E2000≥3.43) for the tea, coffee and wine groups, and discoloration (∆E2000) was seen more in the wine group as compared to tea and coffee. Overall, the control group (distilled water) had the least color change in the three intervals. After bleaching, the color in all specimens returned close to the baseline. The color differences between bleaching and baseline were less than 3.43 for all groups. Statistical analysis results showed that the color change between bleaching and baseline was better for chlorine dioxide as compared to hydrogen peroxide for the tea, coffee and wine groups. The color change observed between bleaching and baseline was significantly better with chlorine dioxide on the wine group (Table 2). Table 1. Comparison of two bleaching agents for different staining beverage. Mean values and SDs of ∆E2000s for intervals of staining and baseline, bleaching and baseline, and bleaching and staining (STBL: Staining and baseline; BBL: Baseline and bleaching; BST: Bleaching and staining; Agent 1: Hydrogen peroxide; Agent 2: Chlorine dioxide P value<0.05 is considered as statistically significant) Table 2. Mean values (SDs) of color change STBL: Staining and baseline; BBL: Baseline and bleaching; BST: Bleaching and staining; Agent 1: Hydrogen peroxide; Agent 2: Chlorine dioxide. P value<0.05 is considered as statistically significant The statistical analysis showed that the color change between bleaching and baseline was better for chlorine dioxide compared to hydrogen peroxide for each stain. Among the stains, wine caused the most discoloration, followed by tea and coffee. Tea stains were bleached well by both agents; coffee and wine were better bleached by chlorine dioxide. Discussion To date, the use of chlorine dioxide in dentistry has been restricted to disinfection of waterlines (11), soft denture liners and acrylic dentures (12). Further, some studies have shown its usage as a mouth rinse ( 13 , 14 , 15 ) to reduce oral malodor. However, to our knowledge, there are no studies stating its usage as a bleaching agent. Restorative composites have been previously subjected to bleaching with hydrogen peroxide, which is the most widely used bleaching agent; nevertheless, its efficacy in bleaching such composites is now being questioned (6). The use of hydrogen peroxide increases the sensitivity of teeth (16) and decreases the enamel-composite bond strength (17). Some researchers have proved that bleaching may adversely affect the surface texture of composites and that surface roughness significantly changes with bleaching, although the extent of these effects varied according to composite shade and bleaching agent (18). It has also been shown that nanocomposites are more prone to staining but are more effectively bleached than microhybrid composites (3). Further, bleaching does not increase the staining susceptibility of nano or microhybrid composites ( 19 , 20 ). In a previous study, the researchers concluded that the effect of bleaching on the surface texture was material-dependent and time-dependent and that bleaching with 38% hydrogen peroxide and 15% carbamide peroxide did not cause major surface texture changes on the polished surfaces of the restorative materials (21). There is also evidence that bleaching of nanocomposites yields color changes to nearly baseline with minimal surface roughness as observed by scanning electron microscopy (22). Due to the deleterious effects of hydrogen peroxide on the surface of composites, it is contra-indicated to be used on them. Future studies should focus on testing chlorine dioxide's effects on the surface of composite, and if it holds good, chlorine dioxide can be a possible alternative to hydrogen peroxide. Most previous studies follow CIELAB for the color assessment of dental materials as indicated by the CIE in 1976. In this study, we used CIEDE2000, which has consistently performed better than other color difference formulae to predict visual results more accurately than with observer uncertainty (23). The composite resin shades were also tested and it was found that the new CIEDE2000 color space is better than CIELAB (24). The present results show that chlorine dioxide is superior to hydrogen peroxide in terms of color of the bleached samples compared to their baseline color before staining. As is true for all in vitro studies, the constraint of reproducing accurate clinical conditions also applies to the present study. Acknowledgements We would like to thank Dr. Tina Purayil, Reader, Manipal College of Dental Sciences for guiding us on this project. Dr. Kishore Ginjupalli, Head of the Department, Dental Materials, Manipal College of Dental Sciences also contributed significantly in the designing of the study. 1 1. Wilson NH, Burke FJ, Mjor IA. Reasons for placement and replacement of restorations of direct restorative materials by a selected group of practitioners in the United Kingdom. Quint Int 1997;28:245-248. Wilson NH Burke FJ Mjor IA Reasons for placement and replacement of restorations of direct restorative materials by a selected group of practitioners in the United Kingdom Quint Int 1997 28 245 248 2 2. Bagheri R, Burrow MF, Tyas M. Influence of food-simulating solutions and surface finish on susceptibility to staining of aesthetic restorative materials. J Dent 2005;33:389-398. Bagheri R Burrow MF Tyas M Influence of food-simulating solutions and surface finish on susceptibility to staining of aesthetic restorative materials J Dent 2005 33 389 398 3 3. Villalta P, Lu H, Okte Z, Garcia-Godoy F, Powers JM. Effects of staining and bleaching on color change of dental composite resins. J Prosth Dent 2006;95:137-142. Villalta P Lu H Okte Z Garcia-Godoy F Powers JM Effects of staining and bleaching on color change of dental composite resins J Prosth Dent 2006 95 137 142 4 4. Ren YF, Feng L, Serban D, et al.. Effects of common beverage colorants on color stability of dental composite resins: the utility of a thermocycling stain challenge model in vitro. J Dent 2012;40: e48-e56. Ren YF Feng L Serban D Effects of common beverage colorants on color stability of dental composite resins: the utility of a thermocycling stain challenge model in vitro J Dent 2012 40 e48 e56 5 5 Norell M, Svedin BH. "Process for the production of chlorine dioxide." U.S. Patent No. 4978517. 18 Dec. 1990. Norell M Svedin BH "Process for the production of chlorine dioxide 4978517 1990 6 6 Haiwood VB. History, safety and effectiveness of current bleaching techniques and applications of the Nightguard vital bleaching technique. Quint Int 1992;23:471-488. Haiwood VB History, safety and effectiveness of current bleaching techniques and applications of the Nightguard vital bleaching technique Quint Int 1992 23 471 488 7 7. Sharma G, Wu W, Dalal EN. The CIEDE2000 color-difference formula: Implementation notes, supplementary test data, and mathematical observations. Col Res App 2005;30:21-30. Sharma G Wu W Dalal EN The CIEDE2000 color-difference formula: Implementation notes, supplementary test data, and mathematical observations Col Res App 2005 30 21 30 8 8. Gujjari AK, Bhatnagar VM, Basavaraju RM. Color stability and flexural strength of poly (methyl methacrylate) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to beverages and food dye: an in vitro study. Indian J Dent Res 2013;24:172-7.10. Gujjari AK Bhatnagar VM Basavaraju RM Color stability and flexural strength of poly (methyl methacrylate) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to beverages and food dye: an in vitro study Indian J Dent Res 2013 24 172 7.10 9 9. Um CM, Ruyter IE. Staining of resin-based veneering materials with coffee and tea. Quint Intl 1991;22:377-386. Um CM Ruyter IE Staining of resin-based veneering materials with coffee and tea Quint Intl 1991 22 377 386 10 10. Vichi A, Ferrari M, Davidson CL. Color and opacity variations in three different resin-based composite products after water aging. Dent Mater. 2004;20:530-534. Vichi A Ferrari M Davidson CL Color and opacity variations in three different resin-based composite products after water aging Dent Mater 2004 20 530 534 11 11. Smith AJ, Bagg J, Hood J. Use of chlorine dioxide to disinfect dental unit waterlines. J Hosp Inf 2001;49:285-288. Smith AJ Bagg J Hood J Use of chlorine dioxide to disinfect dental unit waterlines J Hosp Inf 2001 49 285 288 12 12. Furukawa KK, Niagro FD, Runyan DA, Cameron SM. Effectiveness of chlorine dioxide in disinfection on two soft denture liners. J Prosth Dent 1998;80:723-729. Furukawa KK Niagro FD Runyan DA Cameron SM Effectiveness of chlorine dioxide in disinfection on two soft denture liners J Prosth Dent 1998 80 723 729 13 13. Peruzzo DC, Jandiroba PF, Nogueira Filho G da R. Use of 0.1% chlorine dioxide to inhibit the formation of morning volatile sulphur compounds (VSC). Braz Oral Res 2007;21:70-74. Peruzzo DC Jandiroba PF Nogueira Filho G da R Use of 0.1% chlorine dioxide to inhibit the formation of morning volatile sulphur compounds (VSC) Braz Oral Res 2007 21 70 74 14 14. Frascella J, Gilbert R, Fernandez P. Odor reduction potential of a chlorine dioxide mouthrinse. J Clin Dent 1998;9:39-42. Frascella J Gilbert R Fernandez P Odor reduction potential of a chlorine dioxide mouthrinse J Clin Dent 1998 9 39 42 15 15. Frascella J, Gilbert RD, Fernandez P, Hendler J. Efficacy of a chlorine dioxide-containing mouth rinse in oral malodor. Compend Contin Educ Dent 2000;21:241-244. Frascella J Gilbert RD Fernandez P Hendler J Efficacy of a chlorine dioxide-containing mouth rinse in oral malodor Compend Contin Educ Dent 2000 21 241 244 16 16. Tredwin CJ, Naik S, Lewis NJ, Scully C. Hydrogen peroxide tooth-whitening (bleaching) products: review of adverse effects and safety issues. Brit Dent J 2006;200:371-376. Tredwin CJ Naik S Lewis NJ Scully C Hydrogen peroxide tooth-whitening (bleaching) products: review of adverse effects and safety issues Brit Dent J 2006 200 371 376 17 17. Dishman MV, Covey DA, Baughan LW. The effects of peroxide bleaching on composite to enamel bond strength. Dent Mater 1994;10:33-36. Dishman MV Covey DA Baughan LW The effects of peroxide bleaching on composite to enamel bond strength Dent Mater 1994 10 33 36 18 18. Hafez R, Ahmed D, Yousry M, El-Badrawy W, El-Mowafy O. Effect of in-office bleaching on color and surface roughness of composite restoratives. Eur J Dent 2011;4:118-127. Hafez R Ahmed D Yousry M El-Badrawy W El-Mowafy O Effect of in-office bleaching on color and surface roughness of composite restoratives Eur J Dent 2011 4 118 127 19 19. Turker SB, Biskin T. Effect of three bleaching agents on the surface properties of three different esthetic restorative materials. J Prosth Dent. 2003;89:466-473. Turker SB Biskin T Effect of three bleaching agents on the surface properties of three different esthetic restorative materials J Prosth Dent 2003 89 466 473 20 20. Al Kheraif AA, Qasim SS, Ramakrishnaiah R, Ihtesham ur Rehman et-al.. Effect of different beverages on the color stability and degree of conversion of nano and microhybrid composites. Dent Mater J 2013;32:326-331. Al Kheraif AA Qasim SS Ramakrishnaiah R Rehman Ihtesham ur Effect of different beverages on the color stability and degree of conversion of nano and microhybrid composites Dent Mater J 2013 32 326 331 21 21. Waly GH, El Sharkawy FM. Hydrogen peroxide bleaching: effects on surface roughness, color and staining susceptibility of microhybrid and nanocomposite. J Am Sci 2012;8:190-199. Waly GH El Sharkawy FM Hydrogen peroxide bleaching: effects on surface roughness, color and staining susceptibility of microhybrid and nanocomposite J Am Sci 2012 8 190 199 22 22. Polydorou O, Hellwig E, Auschill TM. The effect of different bleaching agents on the surface texture of restorative materials. Op Dent 2006;31:473-480. Polydorou O Hellwig E Auschill TM The effect of different bleaching agents on the surface texture of restorative materials Op Dent 2006 31 473 480 23 23. Pruthi G, Jain V, Kandpal HC, Mathur VP, Shah N. Effect of bleaching on color change and surface topography of composite restorations. Int J Dent 2010;Article ID 695748. Pruthi G Jain V Kandpal HC Mathur VP Shah N Effect of bleaching on color change and surface topography of composite restorations Int J Dent 2010 695748 24 24. Perez M del M, Saleh A, Yebra A, Pulgar R. Study of the variation between CIELAB delta E * and CIEDE2000 color-differences of resin composites. Dent Mater 2007;26:21-28. Perez M del M Saleh A Study of the variation between CIELAB delta E * and CIEDE2000 color-differences of resin composites Dent Mater 2007 26 21 28