Dental Research JournalMedknow PublicationsComparison of color stability of a composite resin in different color mediaMohammad Reza Malekipour, Ala Sharafi, [...], and Farzaneh ShiraniAdditional article informationAbstractBackground:Color change of composite restorations in different color media during the time is a common problem in esthetic dentistry, causing the need to replace the restoration, and spending a great deal of cost and time to patients. The aim of this study is to investigate the effects of different common drinks consumed by patients on one of the widely used composites in dentistry.Materials and Methods:Sixty-five disk-shaped specimens were prepared with a light-cured composite (Z100-shade A2) and divided into five groups of 13 specimens. Samples of each group were immersed in staining solutions (tea, coffee, lemonade, and cola) and distilled water (as control). Color values (L*, a*, b*) were measured relative to the standard illuminant D65 over a white background, using the CIE L*a*b* system. Color change values were calculated before and after 1, 7, and 14 days of immersion. Repeated measures and one-way analysis of variance (ANOVA) and paired t tests were applied for statistical analysis.Results:Tea and coffee produced the most discoloration, whereas, water exhibited the least color change after immersion for 14 days in Z100 (P < 0.05). After one day of immersion, coffee caused the lowest discoloration in the test composite, compared to tea, cola, distilled water, and lemonade (P < 0.05).Conclusion:Staining solutions and immersion time are significant factors that affect color stability of composite resins.Keywords: Composite resin, discoloration, storage media, timeINTRODUCTIONNowadays patients seek better color-matching restorations and composite resins to satisfy this need.[1] Hence, the proper color match to the adjacent tooth is important not only in the first period of service, but also over a longer period of time.[2] Therefore, the success of composite restorations is due to their color stability over time and one of the important criteria for the composite selection is its color stability during its service.[24]Discoloration of composite resins can be caused by internal or external factors. Internally induced discolorations are permanent and are related to polymer quality, filler type, and amount, as well as the synergist added to the photoinitiator system. In light-cured composite resins, if curing is inadequate, unconverted camphorquinone will cause a yellowish discoloration. Furthermore, other components of the photoinitiator system namely tertiary aromatic or aliphatic amines tend to cause yellow or brown discoloration under the influence of light or heat. The resin's affinity for extrinsic stains is modulated by its conversion rate and physicochemical characteristics, with the water sorption rate being of particular importance. In the oral cavity, because of superficial degradation or a slight penetration and adsorption of staining agents at the superficial layer of the composite resins, discoloration of the surface or subsurface of the resin restorations can result. Moreover, externally induced discoloration can be related to surface roughness, surface integrity, and the polishing technique.[5]Color perception is a psychological issue and is affected by the observer's skill and may be reported differently on different occasions. To overcome such errors, color evaluating devices were employed and the data were recorded in the CIE L*a*b* system.[2] The CIE system uses three-dimensional colorimetric measurements: L* values correspond to the brightness of the color, a* values to the redgreen content, and b* values to the yellowblue content. The color changes (E) are calculated from the L*, a*, and b* values for each specimen, according to the following formula, which determines the three-dimensional color space: Elab* = [(L*)2 + (a*)2 + (b*)2]1/2, while luminosity values (DL*) were reached using L* = L* (tx)L*(t0), where (tx) represents immersion time and (t0) the baseline.[6] A perceptible color change that is E* > 1.0 will be referred to as acceptable up to the value E* = 3.7, in subjective visual determinations made in vitro under optimal lighting conditions.[7]Many investigations have been done on color stability of composites in different beverages. Most of these investigations include the influence of tea and coffee on the color stability of different dental restorative materials, such as, glass ionomer cements, resin veneers, indirect composites, provisional resin materials, and compomers. Some of these experiments show that changes in color and shade are greatest in tea,[8] whereas, some indicated coffee had the most effect in color change in the samples.[9] Hence, the present study is aimed at investigating the effects of different common drinks consumed by patients on one of the common composites in dentistry (Z100 dental restorative composite), which has been investigated without relying on human color perception. The hypothesis of this research study is that different color media have no effect on the color stability of composite resins at different times.MATERIALS AND METHODSSixty-five disk-shaped material specimens (10 mm in diameter 2 mm in thickness) were prepared using a glass mold (ring), with the desired dimensions. The mold was placed on a glass plate and the material was condensed into the mold from the top. The composite material was delivered directly from the syringe into the ring on top of the glass plate. The material was pressed using plastic instruments and a mylar matrix cellulose strip was then placed onto the ring and pressed on the top surface of the material. The tip of a light-curing unit (Coltolux 4, Coltene / Whaledent, Inc., Mahwah, NJ, USA) was positioned at a distance of 2 mm from the material surface and each material was activated by light according to the manufacturers instruction (Z100 3M ESPE, A2 shade / USA). Following this the composites were cured for 40 seconds using a light curing unit (coltolux 2.5-Coltene Waledent Inc./ USA). To ensure adequate curing, the specimens were cured for another 20 seconds after the glass blocks were removed.[10]The upper side of the composites was marked for color testing. In the next step the specimen surfaces were polished using grit-1000 silicon carbide paper disks (soflex-3M ESPE-Ultra thin / USA). It was expected that polishing helped with creating conditions that were closer to the clinical circumstances. Sixty-five composite specimens were randomly divided into five groups of 13 specimens, and labeled. Before placing the samples in different drinks, restoration colors were determined using a spectrophotometer. The first group was stored in distilled water to serve as control. The other groups of specimens were immersed in cola (group 2), Behnoosh Lemonade (group 3), Ahmad Tea (group 4), and Farmand Turkey Coffee (group 5). The samples were soaked in different drinks for periods of one day, seven days, and fourteen days. Prior to testing the color change with a spectrophotometer and after removing the samples from the beverages, the specimens were sanitized from contaminants with an ultrasonic cleaner (SONICA Mod 2200 mh-Soltec 230 / 240 v / ITALY), washed in distilled water for five minutes, and dried with absorbent paper towels.The specimens colors were measured by using a Reflective spectrophotometer (Spectroflash 600- Data Color International/ USA). The aperture size was set to 6 mm and the specimens were exactly aligned with the device. A white background was selected and measurements were made according to the CIE L*a*b* color space relative to the CIE standard illuminant D65. The color changes of the specimens were evaluated using the following formula:[11]

Data were analyzed using the SPSS 12 Software. Repeated measures ANOVA were applied for each group separately and if it was significant, the Paired t-test was also applied. The analysis of variance test was used for the end color changes between different groups at different time durations. P-value less than 0.05 was considered as a significant level.RESULTSTable 1 shows that the amount of E in all groups was greater than 3.3, which indicates that the storage of specimens in different color media and at different time periods causes a clinically diagnosable color change in comparison to the baseline. The highest color change was caused by tea, at different time periods, and the minimum color change was caused by water, after seven and fourteen days, and coffee after one day of submersion.Table 1The comparison between average color changes E in each group for different time durationsThe difference between the color changes of different groups, at different time periods, was statistically significant and the paired t test showed that this difference in E was significant between all time periods in distilled water and coffee. Also DE was significant between the first and seventh and the first and fourteenth day of submersion in coca-cola. One-way analysis of variance shows that color changes in each of the specified time durations among the five groups of beverages are statistically significant (P < 0.05). Least significant difference (LSD) Post Hoc test between groups showed that discoloration in solutions and different time periods did not follow the same pattern. On the other hand, after one day of immersion, the discoloration in coffee solution was significantly lower and after fourteen days discoloration was significantly higher in comparison to other groups. However, tea had the most discoloration for the whole time period [Figure 1].

Figure 1Illustrates comparison between color changes of five groups for different time durationsDISCUSSIONOne of the features that should be investigated and experimented over time is the color stability of the composites. This study was carried out to see whether or not the consumption of beverages at special periods, after placement of restoration, may cause changes in the composite color.The specific objective of this study was to investigate the cumulative effect of the colorant solutions on the dental composites. For this purpose the composite resins were used for one, seven, and fourteen days of immersion treatments, because the composites remained in the oral cavity for a long time, with various staining substances, at different times and periods.Color perception is a psychological issue and is affected by the observer's skill and may be reported differently on different occasions. To overcome such errors color evaluating devices were employed and the data were recorded in the CIE L*a*b* system.[2] In the present study the color change was compared using three values of E, namely, the overall color change after a period of submersion,[12] similar to the research of Bagheri et al.[13,14]The composite disks were finished using the Soft-Lex system, which has a high filler surface with higher knoop hardness, and is less susceptible to chemical degradation.[15]It has been revealed that different beverages are the contributing factors to composite color stability. Also, the soaking time is of great importance, as it affects the composite color stability as well.[2,14] In this study, all the solutions, even distilled water, has caused discoloration in the composite resin, with E higher than 3.7. The rise in the E value of the control sample (distilled water), after being soaked for one day has probably been caused by the increased water absorption by the composite and departure of soluble materials from the structure.[2]If the resin matrix is capable of absorbing water, it is also capable of absorbing any other fluid, which ultimately leads to discoloration. Water sorption is mostly due to direct absorption in the resin matrix. Glass filler particles cannot absorb water, yet they can contribute to water adsorption at the surface of the material. The level of water sorption is a function of the resin content of the material and the strength of the resin-filler interface. Extreme water sorption causes the expansion and plasticizing of the resin, which leads to reduced longevity of the composite resin and hydrolysis of saline, which in turn creates microcracks. As a result, the microcracks or the interfacial gaps at the interface, between the filler and matrix, allow stain penetration and discoloration.[9] Moreover Z100 is a light activated composite, which contains BIS-GMA (Bisphenol A diglycidyl ether dimethacrylate) and TEGDMA (tri ethylene glycol dimethacrylate) as the resin matrix and 66% (volume) silica / zirconia. The filler average particle size is 0.6 m. Different studies have shown that the presence of TEG DMA in materials cause a high amount of hydrophilic capacity and more sensation of Bis-GMA to tonality and water absorption in comparison to Ultra DMA (UDMA). UDMA is more resistant to stain than Bis-GMA. Also, lower water sorption happens in the same situation.[13] Moreover, it has been noted that a composite with large filler particles are more prone to water aging discoloration than a composite with small filler particles, which is in line with the hydrolytic degradation matrix filler interfaces. Thus, a composite with large filler particles has more color permeability than a composite with small filler particles. Accordingly, we can conclude that the Z100 composite, in the presence of small-to-large filler particles, with a BIS-GMA and TEG- DMA resin base, is more prone to color discoloration and water sorption. Clinically, visible discoloration has been seen in all groups, even in the distilled water.[1618]As we know composite Z100 is a microhybrid composite with small and large filler particles, so after the finishing and polishing procedure, many voids are left on the composite surface, which affect its quality and also increase the external discoloration.Adversely, according to Paravina et al.'s study, the apparent color difference is related to rough surfaces, which are a result of the polishing techniques of composites.[19] Polishing the composite up to Grit-1000 greatly helps to better stimulate the clinical circumstance. The results signify that the highest water sorption, and therefore, stain ability occurs during the first day in the samples that are soaked in tea. Similarly, the most water sorption and color change in the seven-day test occurs in the tea-soaked samples. After 14 days of being soaked, tea and coffee samples demonstrate essentially the same color change. The color change in tea and coffee are significantly higher compared to other drinks, which is compatible with the findings in the Bagheri et al. study, due to more color changes of specimens in coffee and tea solutions.[13]In this study all solutions especially coffee, tea, and cola showed visible discoloration in composite. This is in line with the findings obtained in other investigations.[2023] Coffee had the least and the most discoloration on the first and fourteenth day, respectively. This may be due to the delayed effect of coffee on the resin composite discoloration. Adsorption and absorption can be the cause of coffee discoloration. Coffee includes yellow color causing materials that have low polarity, which are released with delay and penetrate to the organic part of the materials, which may be due to the matching of the polymeric materials with the yellow color causing materials in the coffee. Time has been a dominating factor in a further color change in the coffee-soaked samples, as shown by different values of E found over time. This finding is in confirmation with the findings of Gupta et al.[2]In the present study the color change in coffee and tea drinks were essentially the same after 14 days of immersion. Tea showed the most discoloration at all times, which was similar to another study that did not study the role of coffee.[24] On account of denaturized materials in Black tea and a compound with tannins, these materials caused chemical interactions that led to stable discolorations.[25] Both tea and coffee contained yellow colorants with different polarities. Higher polarity components (like those in tea) were eluted first, while lower polarity components (like those in coffee) were eluted at a later time.Discoloration by tea due to adsorption of polar colorants onto the surface of the resin composite materials could be removed by brushing the teeth, whereas, discoloration by coffee was due to both absorption and adsorption of the polar colorants onto the surface of materials. This adsorption and penetration of colorants into the organic phase of the materials were explained by the authors as probably being due to the compatibility of the polymer phase with the yellow colorants of coffee.Furthermore, results of this study showed that the color change in group 2 (Coca) dropped with time. Ruyter demonstrated that cola had the lowest pH and that it might damage the surface integrity of the resin composite materials. It did not produce as much discoloration as coffee or tea, possibly due to its lack of yellow colorant.[26] Furthermore, the findings of Bagheri et al. also lent support to the present study, in that, coffee, tea, and red wine caused more discoloration than soy sauce and cola.[13]The results of the present study provided information on the color stability of the Z100 resin composite and the staining potential of some drinks commonly consumed in daily life. Although the latter could have been well-researched and documented in previous studies, this study showed that colored solution in different time periods caused the composite's discoloration differently.CONCLUSIONSThe color stability of Z100 composite restorative materials was evaluated after one, seven, and fourteen days of immersion, in various staining solutions. Within the limitations of this study, the following conclusions were drawn:1. Filtek Z100 (the universal resin composite) was found to be susceptible to color change2. For the Z100 resin composite restorative material tested, color change values in different color media were greater than or equal to 3.7. In other words, the color change in these staining agents was visually perceptible, as well as, clinically unacceptable. In clinical practice, patients should be aware of the staining effects of the drinks tested in this study, while practitioners should take into consideration the staining susceptibility of the resin composites.FootnotesSource of Support: Nil.Conflict of Interest: None declared.Article informationDent Res J (Isfahan). 2012 Jul-Aug; 9(4): 441446. PMCID: PMC3491332Mohammad Reza Malekipour,1 Ala Sharafi,1 Shantia Kazemi,2 Saber Khazaei,2 and Farzaneh Shirani31Department of Operative Dentistry, Faculty of Dentistry, Azad University, Khorasgan (Isfahan Branch), Isfahan, Iran2Dental Students Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran3Dental Material Research Center and Department of Operative Dentistry, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, IranAddress for correspondence: Dr. Farzaneh Shirani, Dental Materials Research Center and Department of Operative Dentistry, School of Dentistry, Isfahan University of Medical Sciences, Hezar jerib St, Isfahan, Iran. E-mail: fshirani48/at/yahoo.comReceived March 2012; Accepted June 2012.Copyright : Dental Research JournalREFERENCES1. Roberson TM, Heymann HO, Swift EJ. Sturdevant's art and science of operative dentistry. St Louis: Mosby; 2002. 2. Gupta R, Parkash H, Shah N, Jain V. A spectrophotometric evaluation of color changes of various tooth colored veneering materials after exposure to commonly consumed beverages. J Indian Prosthodont Soc. 2005;5:728.3. Abu-Bakr N, Han L, Okamoto A, Iwaku M. Color stability of compomer after immersion in various media. J Esthet Dent. 2000;12:25863. [PubMed]4. Kolbeck C, Rosentritt M, Lang R, Handel G. Discoloration of facing and restorative composites by UV-irradiation and staining food. Dent Mater. 2006;22:638. [PubMed]5. Gaintantzopoulou M, Kakaboura A, Vougiouklakis G. Colour stability of tooth-coloured restorative materials. Eur J Prosthodont Restor Dent. 2005;13:516. [PubMed]6. Powers JM, Sakaguchi RL. Craig's restorative dental materials. St Louis, MO: Mosby Elsevier; 2006. 7. Domingos PA, Garcia PP, Oliveira AL, Palma-Dibb RG. Composite resin color stability: Influence of light sources and immersion media. J Appl Oral Sci. 2011;19:20411. [PubMed]8. Turker SB, Kocak A, Aktepe E. Effect of five staining solutions on the colour stability of two acrylics and three composite resins based provisional restorations. Eur J Prosthodont Restor Dent. 2006;14:1215. [PubMed]9. Ertas E, Guler AU, Yucel AC, Koprulu H, Guler E. Color stability of resin composites after immersion in different drinks. Dent Mater J. 2006;25:3716. [PubMed]10. Awliya WY, Al-Alwani DJ, Gashmer ES, Al-Mandil HB. The Effect of commonly used types of coffee on surface microhardness and color stability of resin-based composite restoration. Saudi Dent J. 2010;22:18993. [PMC free article] [PubMed]11. Johnston WM. Color measurement in dentistry. J Dent. 2009;37(Suppl 1):e26. [PubMed]12. Patel SB, Gordan VV, Barrett AA, Shen C. The effect of surface finishing and storage solutions on the color stability of resin-based composites. J Am Dent Assoc. 2004;135:58794. quiz 654. [PubMed]13. 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;33:38998. [PubMed]14. Yannikakis SA, Zissis AJ, Polyzois GL, Caroni C. Color stability of provisional resin restorative materials. J Prosthet Dent. 1998;80:5339. [PubMed]15. Lee YK, Powers JM. Discoloration of dental resin composites after immersion in a series of organic and chemical solutions. J Biomed Mater Res B Appl Biomater. 2005;73:3617. [PubMed]16. Ferracane JL, Marker VA. Solvent degradation and reduced fracture toughness in aged composites. J Dent Res. 1992;71:139. [PubMed]17. Manabe A, Kato Y, Finger WJ, Kanehira M, Komatsu M. Discoloration of coating resins exposed to staining solutions in vitro. Dent Mater J. 2009;28:33843. [PubMed]18. Vichi A, Ferrari M, Davidson CL. Color and opacity variations in three different resin-based composite products after water aging. Dent Mater. 2004;20:5304. [PubMed]19. Paravina RD, Kimura M, Powers JM. Evaluation of polymerization-dependent changes in color and translucency of resin composites using two formulae. Odontology. 2005;93:4651. [PubMed]20. Iazzetti G, Burgess JO, Gardiner D, Ripps A. Color stability of fluoride-containing restorative materials. Oper Dent. 2000;25:5205. [PubMed]21. Lu H, Roeder LB, Lei L, Powers JM. Effect of surface roughness on stain resistance of dental resin composites. J Esthet Restor Dent. 2005;17:1028. [PubMed]22. Um CM, Ruyter IE. Staining of resin-based veneering materials with coffee and tea. Quintessence Int. 1991;22:37786. [PubMed]23. Villalta P, Lu H, Okte Z, Garcia-Godoy F, Powers JM. Effects of staining and bleaching on color change of dental composite resins. J Prosthet Dent. 2006;95:13742. [PubMed]24. Ghahramanloo A, Madani AS, Sohrabi K, Sabzevari S. An evaluation of color stability of reinforced composite resin compared with dental porcelain in commonly consumed beverages. J Calif Dent Assoc. 2008;36:67380. [PubMed]25. Lee YK, Powers JM. Combined effect of staining substances on the discoloration of esthetic Class V dental restorative materials. J Mater Sci Mater Med. 2007;18:16570. [PubMed]26. Ruyter IE. Composites-characterization of composite filling materials: Reactor response. Adv Dent Res. 1988;2:1229. [PubMed]

Colour Changes of Tooth-Coloured Restorative Dental Materials Immersed in Food Simulating Solution Aimi Razak, Ashanti Long, Shivaani Sivananda- DDS Year 5 Student, MAHSA University, Kuala LumpurDr. Shekhar Bhatia, BDS, MDS, Lecturer in Conservative Dentistry, Faculty of Dentistry, MAHSA University, Kuala LumpurDr. Shivani Kohli, BDS, MDS, Lecturer in Prosthetics Dentistry, Faculty of Dentistry, MAHSA University, Kuala LumpurDr. Ratnasothy a/l N Subramaniam, Associate Professor, Family Dentistry, Faculty of Dentistry, MAHSA University, Kuala LumpurAbtractThe study examines the surface staining of two different types of photopolymerised composite by tea. Thirty samples each from two generations of composite with different filler particle sizes, Filtek Z250 (3M ESPE) microhybrid and Filtek Z350 XT (3M ESPE) nanohybrid of A2 shade were subjected to an experimental 7-day staining period with each of them immersed in a solution containing 75gm of Lipton tea and 15gm of sugar and kept in 37 Celsius to simulate the temperature of the oral cavity.After 1,3,5 and 7 days, visual examination of all samples were done to detect colour difference of each sample by comparison, using the Lobene Stain Index, which uses a grading system ranging from 0 to 3.It was found that both restorative material used in this study were susceptible to staining by tea. However, Filtek Z350 XT showed more resistance to staining, while Filtek Z250 produced more stained samples. The colour changes of both groups of samples were found to be statistically significant only for day one of the study (p < 0.05). However, the results showed insignificant findings on the 3rd, 5th and 7th day (p > 0.05).In conclusion, composite restorative materials are susceptible to staining regardless of the composition and particle size, but the degree in which it affects the aesthetic value is dependent upon specific composition of said material and other external conditions.

Keyword:colour, composite, tea solution, staining.

INTRODUCTIONAesthetic failure is one of the most common reasons for the replacement of restorations.1 Currently, resin-based composite (RBC) materials are the most prominent esthetic restorative materials because of their universal usage, minimal loss of tooth structure, and ability to be directly placed without laboratory procedures.2 A good combination of the tooth colour and the initial colour of the material before curing is an important clinical factor for a successful outcome. More importantly, this combination must remain after the material is completely cured and throughout the life time of the restoration. Even though manufacturers found a breakthrough in light-cured formulations of composite materials, which have considerably better aesthetic quality due to the exclusion of benzoyl peroxide in its composition, most users note discolouration of restorative material over a period of years. This still pose as a major problem for aesthetic restorations.3-5Discolouration of tooth-coloured, resin-based materials may be caused by intrinsic or extrinsic factors. The intrinsic factors in the deeper layers of the materials involve a variery of factors related to their composition.1,3 More specifically, the type of photo-initiator, nature of resin matrix, filler content, filler particle size distribution are related to colour stability. Colour stability is also influenced by the intensity and duration of polymerization and, consequently, by the degree of conversion. Staining of composite materials could be a consequence of (1) alteration of resin matrix, (b) alteration in the interface between matrix and fillers, (c) change in tertiary amines in composite under heat and light, (d) oxidation in structures of polymer matrix, and (e) oxidation of unreacted pendant methylacrylate group. In addition to that, water accumulation has also been reported to be responsible for internal color change. Water plays an important role in chemical degradation process such as oxidation and hydrolysis and the subsequent change of the optical properties of the provisional restorative materials.The extrinsic factor that contributes to staining of composite are : (a) production of coloured components in plaque by chromogenic bacteria, (b) retention of coloured substances from dietary constituents passing through the oral cavity, and (c) formation of coloured products from the chemical transformation of pellicle components. Factors such as diet (coffee, tea, and red wine), smoking, exposure to antimicrobial agents, and daily teeth cleaning affect extrinsic stain development.6-9This study focuses on evaluating the colour changes of two different tooth-coloured restorative dental materials immersed in food simulating solutions (i.e. tea) that have been subjected to accelerated aging, and if possible, to relate staining capability of said materials to the difference in their composition.AIMS & OBJECTIVESThere are two main aims and objectives of this research project are as follows:To evaluate the degree of staining of two different composites (3M Filtek Z 250 & 3M Filtek Z 350 XT ) in a food simulating solution ( Tea ).To evaluate the effect of duration on the degree of staining in the composites immersed in a food simulating solution.MATERIALS & METHODSMaterials 1.Restorative material (Table 1)Filtek Z250 ( 3M ESPE )Filtek Z350 XT ( 3M ESPE )2.Drinking straws3.Light curing unit ( Motion Blue Life LED 320 )4.Carborandom disc ( 25 x 0.3 mm Separating Disc Secudisk )5.Opti Discs ( OptiDisc Kerr Course/ Medium, Fine, Extra Fine )6.Deionized Distilled Water (DDW)7.Tea Powder / Tea Bags ( Lipton )8.Incubator9.Sugar ( Prai Granulated Sugar )10.Electronic Digital Caliper ( Kern Germany )11.Measuring Cylinder 100 ml12.Electronic Balance ( A & D Company Limited ) Fx 300i13.Hand Instruments : Plugger, Ball burnisher, Metal rulerMethodologyThis is an in vitro study that has been carried out at MAHSA University. The restorative materials tested in this study are Filtek Z250 (3M ESPE ) and Filtek Z350 XT (3M ESPE). 60 samples are prepared with 30 samples for each group. The restorative material is then packed into drinking straws with a diameter of 13 mm and thickness of 1 mm. These specimens were then light cured for 40 seconds with a light curing unit (Motion Blue Life LED 320 ) and then sectioned with a carborandom disc ( 25 x 0.3 mm Separating Disc Secudisk ) according to 1 mm thickness to fabricate a total of 60 individual discs. The samples were then polished with Opti Discs (OptiDisc Kerr) from coarse or medium to fine and then finally extra - fine. This is done by the same operator to reduce variability.All the 60 specimens are placed in a container containing deionized distilled water (DDW) at 37C for 24 hours as a baseline measurement. After 24 hours, the specimens were taken out from the deionized distilled water and a baseline colour measurement will be made after blot drying the specimens.All the 30 samples from both groups ( 60 samples ) will be immersed into tea solution (Lipton Brand) where each solution is prepared using 15gm of tea powder, 10 gm sugar (PRAI Brand Granulated Sugar) and 100ml of hot water. All the discs will be immersed into the solutions after the solution becomes cold.The specimens are then kept in each solution for a period of 1 day, 2 days, 3 days, 4 days, 5 days, 6 days and 1 week. This time period is done to stimulate the period of continuous exposure and the specimens will be stored in an incubator at 37C.After each period, the discs from each sub group were removed and irrigate under running water for 20 seconds and blotted dry with tissue paper before colour measurement. Stains were assessed visually and recorded using Lobene Stain Index10 (which is based on these four scores:0 = no stain 1 = light stain (yellow to light brown or gray)2 = moderate stain (medium brown)3 = heavy stain (dark brown to black)For this assessment, each sample is measured by two investigators which are by 2 researchers. Firstly, one researcher will assess the results and then the second researcher will assess the results. These results are then combined and an average result of both will be taken.RESULTSStatistical AnalysisThe statistical analysis was analyzed using Independent t-Test.Mean value was calculated separately for Filtek Z250 and Filetk Z350 XT for day 1, 3, 5 and 7. Generally, Filtek Z250 marked a higher mean value compared to Filetk Z350 XT for all the days.The formula for the sample mean is as follows:The values obtained were summarized in Table 2 and Graph 1 explains the degree of staining based on the mean value obtained for Filtek Z250 and Filtek Z350 XT for 1 day, 3 days, 5 days and 7 days.DISCUSSIONTea has been proven to play a significant role in causing discolouration of composite resins through the act of adsorption or absorption. Staining solutions and immersion time were significant factors that affected colour stability of the composite resins after polishing. 3M ESPE Filtek Z350 XT, which is a nanohybrid, was chosen because it is currently the choice of composite restorative material used in many dental clinics. The other composite resin studied was 3M ESPE Filtek Z250 Universal Restoration, a microhybrid composite from the same manufacturer.For Filtek Z250, which is the predecessor to Filtek Z350XT, the 3 major components of composite restorative material are retained from the previous make of composite from the same brand (Filtek Z100). Here, the majority of TEGDMA has been replaced with a blend of UDMA and Bis-EMA . Both these compounds are of high molecular weight, and therefore have lesser double bonds per unit of weight. The high molecular weight results in less shrinkage, decreased aging, and a slightly softer matrix. These resins impart a greater hydrophobicity and are less sensitive to changes in atmospheric pressure.5 Filler particle size for this make is also a breakthrough in the microhybrid region, with particle zirconia/silica particle distribution ranging from 0.01m to 3.5 m. The average size is around 0.6 m.Filtek Z350 XT Universal Restorative is a visible light-activated composite designed for use in anterior and posterior restorations. This material consists of three primary ingredients: an organic matrix, inorganic filler particles, and a coupling agent. Other ingredients include colour stabilizers, pigments, and an activation system. The organic resin matrix contains mainly UDMA ((urethane dimethacrylate) and Bis-EMA (Bisphenol A polyethethyleneglycol dietherdimethacrylate).UDMA and Bis-EMA) resins are of higher molecular weight than TEGDMA and therefore have fewer double bonds per unit of weight. The higher molecular weight of the resin results in less shrinkage, improved aging and a slightly softer resin. TEGDMA and PEGDMA are used in minor amounts to adjust the viscosity. PEGDMA (hydrophobic) was used to replace part of the TEGDMA (hydrophilic) component to moderate shrinkage in Filtek Z350 XT restorative.11As for the filler particles, the manufacturer used a combination of non-agglomerated/ non aggregated 0.020 m silica filler, non agglomerated/ non aggregated 0.004 to 0.011 m zirconia filler, and aggregated zirconia/silica cluster fillers (comprised of 20nm silica and 4 to 11 nm zirconia filler particles).In this study, tea was chosen as this beverage is a staple drink in Malaysians daily dietary habits. Tea contains Tannin (tannic acid), a substance which gives it its yellowish-brown appearance. Tannin has been found to be the source of discolouration in composite resins. The presence of tannic acid causes swelling of the restoration, thereby manipulating the susceptibility of the composite surface to staining.12Sugar was added because the presence of sugar in coffee and tea increased the colour difference compared to coffee or tea without sugar for light-polymerised composite material and microhybrid composites.8,10 Also, most Malaysians generally consume tea with sugar as accompaniment. The omission of milk in this study is due to established laboratory studies showing the protective nature of milk against tooth erosion. Milk contains a high concentration of calcium, which, along with phosphate, may have a protective effect on tooth enamel and consequently resist deterioration of tooth surface. Cows milk has shown that it can strengthen tooth enamel by remineralisation after exposure to acidic drinks.13 Therefore, even though tea is acidic and milk is alkaline in nature, it is thought that the presence of milk in the solution would offset, if not mar the actual extent of discolouration tea would have on the samples. Low consumption of milk was also a reason behind the exclusion of milk from this study, which is concurrent with a data from the national survey among adults in Malaysia in 2006. The survey reports that the average consumption of milk among adults was 0.14 serving per day (1 serving = 250 mL; 0.14 serving= 35 mL) compared to the recommendation of one to two servings per day. Only 17.1% of the adult population consumed milk with the frequency of 1.4 times daily.8Samples were kept at 37 Celcius constantly in incubator throughout the entire study to simulate the average temperature in the oral cavity. Although this contradicts the fact that most people prefer hot tea, it was presumed that the temperature of the beverage drops soon after consumption, therefore, the samples remain at normal human body temperature for most of the period. Furthermore, previous studies on this topic also warranted the selection of the temperature above. 8,10The duration of the study considered the cumulative effect of months or years of tea consumption, which elucidates the constant exposure of samples to the staining solution. It purely deliberated the extent of staining on composite materials, excluding the effect normal act of oral hygiene routine such as tooth brushing and the use of mouth rinses.For the purpose of synchronizing and standardizing the finished products, polishing was done by a sole operator, using polishing discs (OptiDisc by Kerr) ranging from coarse/medium, fine, to extra fine. A high-gloss surface is generally considered less-susceptible to staining.10 Rough surfaces mechanically retain surface stains more than smooth surfaces. It can be concluded that the rougher the finished surface, the more vulnerable the restoration is to bacterial and plaque accumulation. 11 Also, a poorly-finished restoration leads to increased surface area for adsorption of pigments from food, allowing discolouration along marginal lines of the restoration to occur. 6,11Discolouration of composite resins can be evaluated via various instruments. In this study, Lobene (1968)14 Stain Index was used for assessment of the extent of staining by this beverage. The score was given accordingly from the lightest to the darkest based on four scores from 0 to 3.10. This method was chosen due to the limitations of the research team to utilise more accurate equipment such as a spectrophotometer. It has been found that the human eye is best in detecting colour difference by comparison. The National Bureau of Standards (NBS) established a sophisticated classification to describe colour change difference by NBS units. They say that the acceptable limit for the colour shift is E 0.05(Not Significant)

7 daysZ250Z350XT2.15 (0.645)2.08 (0.671)0.412> 0.05(Not Significant)

Graph 1: Colour changes for 3M Filtek 250 and 3M Filtek 350XT in tea solution.

Pengaruh Lama Perendaman Dalam Larutan Teh Hitam Terhadap Perubahan Warna Pada Resin Komposit HybridThe Effect Of Lengthy Immersion In Black Tea Solution On Hybrid Composite Resin Color ChangeKTI KG 2007Undergraduate Theses from YOPTUMYFKPP / 2012-06-13 00:20:15Oleh : Bungawati AristianaDibuat : 2012-06-13, dengan 1 file

Keyword :Resin komposit hybrid, teh hitam, perubahan warna, lama perendamanSubjek :Resin komposit hybridKepala Subjek :teh hitamNomor Panggil (DDC) :20070340070Url :http://FK UMYResin komposit hybrid merupakan material tumpatan sewarna gigi. Resin komposit hybrid mempunyai sifat menyerap air secara difusi pada resin matriks dan bersifat adsorpsi pada bahan pengisi. Teh hitam merupakan salah satu jenis minuman yang paling sering dikonsumsi oleh masyarakat Indonesia. Teh hitam mempunyai zat warna katekin yang bila melalui proses oksidasi enzimatis memiliki sifat larut dalam air. Penelitian ini bertujuan untuk mengetahui pengaruh lama perendaman larutan teh hitam terhadap perubahan warna Resin komposit hybrid.Sampel pada penelitian ini adalah Resin komposit hybrid dengan ukuran diameter 11 mm dan tebal 2 mm, sebanyak 20 buah yang terbagi dalam 4 kelompok. Kelompok pertama direndam dalam akuades sebagai kelompok control dan 3 kelompok lainnya direndam dalam larutan teh hitam yang masing masing selama 5 hari, 1 hari dan 15 hari. Perubahan warna akan diukur dengan monochromameter. Analisis data menggunakan Anava 1 jalur dan LSD0,05.Hasil uji Anava satu jalur menunjukkan adanya pengaruh lama perendaman dalam larutan teh hitam terhadap perubahan warna Resin komposit hybrid (p0,5).Hasil uji LSD0,05 menunjukkan adanya nilai perubahan warna yang signifikan antara setiap kelompok.Kesimpulan penelitian ini adalah perubahan warna resin komposit hybrid paling signifikan terjadi pada kelompok lama perendaman 15 hari.Deskripsi Alternatif :

Hybrid composite resin is a tooth colored material filling. Hybrid composite resin has the properties of absorbing water diffusion in the resin matrix and the character of adsorption on the filler material. Black tea is one of most popular beverage that consumed by the indonesian people. The cathechin colorant in black tea which is soluble in water through enzymatic oxidation process. This study aims is to determine the influence of immersion solution of black tea to change the color of a hybrid composite resin.The sample of this study is a hybrid composite resin with a diameter of 11 mm and 2 mm thick, 20 pieces are divided into 4 groups. The first group was immersion in distilled water as a control group and 3 other group immersed in a solution of black tea, each for 5 days, 10 days, and 15 days. The color change will be measured by monochromameter. Data analysis using One Way Anava and LSD0,05.The result of One Way Anav shows the effect immersion in a solution of black tea on a hybrid composite resin color changes (p0,05). LSD0,05 results showed a significant change in color values between each group. The conclusion of this research is the color transformation of hybrid composite resin is effected significancy in the most long time immersion, that is 15 days immersion in black tea solution.Copyrights :Copyright @ 2001 by Digilib Fakultas Kedokteran UMY. Verbatim copying and distribution of this entire article is permitted by author in any medium, provided this notice is preserved.

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Oper Dent. 2007 Nov-Dec;32(6):616-22.The effect of curing units and staining solutions on the color stability of resin composites.Yazici AR1, Celik C, Dayanga B, Ozgnaltay G.Author information AbstractThis study investigated the effects of two different light curing units and two staining solutions on the color stability of a hybrid composite and a nanohybrid composite after different immersion periods. Thirty disk-shaped specimens (10 mm in diameter, 2-mm thick) were fabricated for each of the resin composites, Clearfil AP-X and Filtek Supreme. The specimens were randomly divided into two groups according to the curing unit used: Group I specimens (n = 15) were cured with a quartz-tungsten-halogen (QTH) light for 40 seconds, and Group II specimens (n = 15) were cured with a light-emitting diode (LED) unit in standard mode for 40 seconds. The specimens were incubated in 100% humidity at 37 degrees C for 24 hours. Then, the baseline color values (L*, a*, b*) of each specimen were measured with a spectrophotometer according to the CIELab color scale. After baseline color measurements, five randomly selected specimens from each group (Groups I and II) were immersed in one of two staining solutions (tea or coffee) or distilled water (control). After 1, 7 and 30 days of immersion, the color values of each specimen were remeasured and the color change value (deltaE*ab) calculated. Color changes caused by immersion in tea and coffee for 30 days were only perceptible in the Clearfil AP-X specimens cured with QTH or LED. In the Filtek Supreme specimens, coffee perceptibly stained the teeth after all immersion periods and tea stained after 30 days. Polymerization with QTH or LED did not cause any significant difference in the color stability of Clearfil AP-X or Filtek Supreme. While there were no significant differences between staining solutions in the Clearfil AP-X specimens cured with LED after one and seven days of storage and one day of storage in the QTH cured specimens, significant differences were observed between water and coffee after seven days of storage. In the Filtek Supreme specimens cured with QTH or LED, there were statistically significant differences between the staining solutions after one and seven days of storage. After 30 days of storage, no significant difference was found between tea and coffee in either resin composite cured with QTH or LED. The effect of the staining solutions (tea, coffee) on color changes in composites was immersion time and resin-material dependent.PMID: 18051013 [PubMed - indexed for MEDLINE

Quintessence Int. 2010 Sep;41(8):695-702.A long-term laboratory test on staining susceptibility of esthetic composite resin materials.Ardu S1, Braut V, Gutemberg D, Krejci I, Dietschi D, Feilzer AJ.AbstractOBJECTIVE: To evaluate the color stability of composite resin types designed for esthetic anterior restorations when continuously exposed to various staining agents.METHOD AND MATERIALS: Thirty-six disk-shaped specimens were made of each of 12 composite materials (1 microfilled and 11 hybrid composites). After dry storage at 37 degrees C for 24 hours in an incubator (INP-500, Memmert), the initial color of each specimen was assessed by a calibrated reflectance spectrophotometer (SpectroShade). Specimens were immersed in five staining solutions or dry stored (control). All specimens were kept in an incubator at 37 degrees C for 99 days. Test solutions were changed every 14th day to avoid bacteria or yeast contamination. After 99 days of storage, spectrophotometric measurements were again performed and L*a*b* scores once more recorded to determine the color changes.RESULTS: Wine proved to have the highest staining potential followed by coffee, tea, orange juice, and cola, which had the lowest staining potential. The highest color change measured against a white background was observed for Durafill (Heraeus Kulzer) in wine (DeltaE = 62.3), while the least staining was found for Enamel HFO (Micerium) in cola (DeltaE = 3.5). The highest color change measured against a black background was observed for EsthetX (Dentsply) in wine (DeltaE = 46.0), while the least staining was observed for Enamel HFO in cola (DeltaE = 2.5).CONCLUSION: Composite staining susceptibility proved to vary among composite structure and brands. Potential discoloration might be limited by dietary restriction based on such in vitro evaluation.J Dent. 2012 Dec;40 Suppl 2:e55-63. doi: 10.1016/j.jdent.2012.06.002. Epub 2012 Jun 17.Effects of sports drinks on color stability of nanofilled and microhybrid composites after long-term immersion.Erdemir U1, Yildiz E, Eren MM.Author information AbstractOBJECTIVES: This study assessed the effects of three sports drinks on the color stability of two nanofilled and two microhybrid composite materials after 1-month and 6-month periods.MATERIALS AND METHODS: Twenty-eight disc-shaped specimens (diameter: 10mm and thickness: 2mm) each were made from four resin composites (Clearfil Majesty Posterior, Filtek Supreme, Clearfil APX, and Filtek Z250). All the specimens were stored in distilled water for 24h at 37C. Then, the baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color scale. Seven randomly selected specimens from each composite material were then immersed in one of the three sports drinks (Powerade, Red Bull, and Burn) or distilled water (control) for 1 and 6 months. After each immersion, the color values of each specimen were remeasured, and the color change value (E) was calculated. The data were evaluated using the Kruskal-Wallis and Mann-Whitney U-tests.RESULTS: The tested resin composites showed color changes over the 6-month evaluation periods. At 1 month, highest level of color changes was observed in the Clearfil APX specimens immersed in Burn (p