Influence of Coca-cola on Surface Roughness and Microhardness of Flexible Denture Base Material
Two potential problems commonly associated with flexible denture base material are surface roughness and the reduction of microhardness due to many reasons, rough surface can cause bacterial collection and the patient feels discomfort, and the possibility of the denture scratched when the surface hardness is reduced. The aim of this study was to evaluate the influence of Coca-cola on the surface quality of the flexible denture base material represented by the surface roughness and microhardness. A total of (10) samples were prepared for this study with the dimension of ( 40mm, 10mm, 3mm) length, width, and height respectively from thermo-plastic flexible resin (X-flexible capsules, color; K2 , size; L\China) by the conventional methods following the manufacturer instructions. The samples were immersed in Coca-cola drink for 12 days at room temperature. This period represents the average of one year of the beverage consumption, the drink has been changing daily.The samples were marked randomly and kept in special containers, and each sample has two rectangular surfaces used for the tests. One side is used for microhardness test and the other side used for the surface roughness test. The first tests were done before immersing the samples in coca-cola as control group. And after immersing the second tests were done as experimental group. In this study the data was analyzed using Independent samples (T- test). And results showed that there is no statistically significant difference in the surface roughness of the samples before and after immersing in Coca-cola (P-value > 0,05), while the microhardness test showed statistically a significant difference (P-value < 0,05) before and after immersing in Coca-cola. The surface roughness of flexible thermoplastic resin is not affected by coca-cola drink. While the levels of mirohardness showed decreasing after immersion in coca-cola drink. Therefore, the flexible thermoplastic material could be damaged if it is subjected to extra consumption of Coca-cola drink by the patient and this leads to lessen the amount of hardness by the time that could affect the efficiency of the prostheses, also could affect the mechanical bonding between artificial teeth and flexible denture base.