## 4 Discussion
Previous studies showed that tea and coffee result in a greater color change than Coca-Cola [15]. Other studies also reported that the yellow coloring of tea and coffee was caused by the presence of highly polar compounds that precipitate on the surface by adsorption [2]. Additionally, other researchers have proved that the presence of tannin-containing components and denaturing elements in yellow tea cause chemical alterations that produce persistent discoloration [40]. Coca-Cola caused discoloration of composite resin because it was a carbonated soft drink that was yellow-brown in color. Additionally, both Coca-Cola and orange juice, besides their decolorizing effect, were found to be abrasive to composite resins [41]. Finally, other variables can have a significant influence of mechanical behavior of composite materials, such as depth of cure [42], curing type [43], and wear [44]. Therefore, these variables could have an effect also on color stability. It would be interesting to include also these factors in future research reports. [PERSON] et al. compared color stability after solution immersion of microhybrid and nanohybrid composites, reporting the maximum discoloration in microhybrid composite and Coke [45]. [PERSON] et al. also investigated four different nanohybrid composites after immersion in Red Bull, Coca-Cola, and Dimes Lemonade, discovering that all three soft drinks affected the color stability of the composite resin [46]. [PERSON] et al. assessed the color stability of flow composites after immersion in tea, coffee, and wine and found that coffee and wine provided the greatest color change [47]. According to [PERSON] et al., fillers are added to dental composites to enhance their strength and reflectivity. By lowering the amount of the organic component, an increase in the amount of filler will also decrease contraction stress after polymerization and the material's subsequent shrinkage. Additionally, fillers make it possible to obtain materials with a high level of esthetic value as well as excellent handling [48]. Orange juice generated discoloration in the composite resin due to the juice's staining and erosive effects on the components and the presence of yellow pigments. Although orange juice has a pH of 3.8, low-pH staining solutions chemically erode the composite material. According to the study, the presence of orthophosphoric as well as carbonic acids causes a color change in Coca-Cola. Coca-Cola has a pH of around 2.4, caused by the presence of citric acid and resulting in the release of ions from its matrix. The study found that Coca-Cola discolored more than orange juice, which matched our findings [41]. In clinical settings, as well as in vitro, certain reactions can cause color changes. In vivo, because of the rinsing action of saliva and the patient's oral hygiene performance, these alterations and discoloration of tooth-colored restorative materials become less popular [49]. The optical characteristics that differ caused by exposure to water could be explained by the material's composition and how it is affected by environmental conditions. According to previous research, water could penetrate the matrix or the filler-matrix connection in resin-based composite material. Cracking in the resin matrices, as well as interfacial gaps between the filler and the resin matrix, are caused by swelling and plasticizing effects, allowing stains to penetrate and discolor the restoration [50]. In the realm of dental materials and color measurement methodologies, modern digital systems have introduced an era of efficiency, producing highly dependable and easily analyzed visual results [51]. In CIE Lab's color space, the L value is known as lightness, and if a mismatch occurs, it was demonstrated to be the most easily detectable color dimension. The study by [PERSON] et al. demonstrated tooth color measurement by using both a spectrophotometer and a SpectroShade Micro and found that evaluations of color-measuring devices could be influenced by several processing mistakes with each device [52].