MATERIALE PLASTICE ♦ 51♦ No. 3 ♦ 2014 http://www.revmaterialeplastice.ro 328 Influence of Different Coloured Solutions on Some Plastics used for Prosthetic Restoration Materials CRISTINA KREMS 1 , COSMIN SINESCU 2 *, PAUL CORNEL FREIMAN 3 *, ANDREEA-CODRUTA COJOCARIU 1 , MEDA LAVINIA NEGRUTIU 2 , CODRUTA ANGELA PODARIU 2 1 University of Medicine and Pharmacy “Victor Babes” Timisoara, Prosthetics Dental Faculty, 2 Eftimie Murgu Sq., 300041, Timisoara, Romania 2 University of Medicine and Pharmacy “Victor Babes” from Timisoara, Faculty of Dentistry, 2 Eftimie Murgu Sq., 300041, Timisoara, Romania 3 “VasileGoldis” Western University of Arad, 94 Revolutiei Blv., 310025, Arad, Romania The purpose of this study was to evaluate colour changes of aesthetic fixed prosthetic restoration materials, when these materials are exposed to a drink rich in colorants, in this case, cola, coffee and red wine. For the study were required 18 fixed partial dentures: 6 integral polymeric dentures, 6 metal-polymeric dentures and 6 metal-ceramic dentures. To verify the colour there were used: VITA EASYSHADE spectrophotometer and the VITA shade for ceramic restorations. Following the results obtained, it was concluded that prosthetic composite resin changes quickly their colour, compared to the ceramic. Also, the liquid that affect the most in changing the colour of this material is coffee. Keywords: composite resin, colour change, aesthetic restorative materials * email: freimannp@yahoo.com; T el: 0722663315; minosinescu@yahoo.com; Tel.: 0722280132 At present aesthetic dentistry passes through modifications and improvements that have a tendency to an efficient development of techniques and materials to fulfill the patients requirements, which in turn, in addition to effective therapeutic treatments are looking for an as natural as possible aesthetic aspect. One of these materials is represented by composite resins, because it shows similar properties with those of the natural teeth [1]. However, in spite of surprisingly good results which can be obtained after such restorations, if was noticed that the lifetime of a acrylate or polymeric dental crowns are much less, compared with a ceramic dental crown, for example. The colour stability represents one of the most important factors for the selection of composite resin materials in aesthetic restorations. The success and the failure of such prosthetic restorations depend on the colour stability and its changes, their evaluation resulting to improvement thereafter the chemical structure leading to improvements in the dental field of aesthetics [2]. The colour modifications might be caused by intrinsic factors namely the quality of the resin matrix, photoinitiators as well as anorganic filling material [3-4]. Change of colour is mainly due to extrinsic absorption of colorants existing in food and drinks. The result of interactions between the external colorants and resin composite material components resulting in damage of colour[5]. There are numerous studies in vitro, which demonstrated that the common drinks like coffee, red wine [6-9] or cola drinks [10-12] may cause visible alteration in the colour of composite resins surfaces. This fact is mainly due to the porosity of these materials results in losing the original properties, among the effects are found: the halitosis, changing the colour to these contributing the lack of corresponding oral hygiene. Through vigorous hygiene procedures can be removed colorants absorbed on the surface of the material, instead, colorants absorbed in the deep matrix of the material most of the time requires the replacement of the fixed prosthetic restoration. The lack of the porosity of ceramics and its biocompatibility with the oral environment represented the main reason for which this kind of prosthetic construct has been chosen as being the term of comparison in the idea that studies have shown that ceramic prosthetic restorations have the ability to maintain the original colour a longer time. Experimental part Materials and methods For this study were needed 18 fixed prosthetic restorations: 6 integral polymeric partial prosthesis, 6metal- polymeric fixed partial prosthesis and 6metal-ceramic fixed partial prosthesis. There have been also used, six receptacles: two filled with red wine, two with coffee and other two with cola drinks. In each of the six receptacles were immersed: an integral polymeric fixed partial prosthesis, a fixed partial metal-ceramic prosthesis and a fixed partial metal-polymeric prosthesis. The six receptacles have been divided into two categories: three receptacles, with each of the three drinks, in which no thermic factor has occurred and the other three receptacles in which the intervened and thermic factor. The three sets of tests in which did not interfere the thermic factor were left for 90 days at a constant temperature of 37 o C, receptacles liquids being changed every day. In the other three receptacles, in which thermal factor intervened, the samples were moved constant, every 10 minutes at a temperature of 50°C at temperatures of - 18° C, two hours per day for the same number of days, in order to simulate an usual masticatory habit. A very important aspect was that before immersion in solutions, all 18 restorations have been checked their colour by using a spectrophotometer,VITA EASYSHADE (fig.1).