Effects Of Staining Solutions On The Color Stability,translucency And Surface Roughness Of CAD/CAM Aesthetic Restorative Materials

Background:CAD/CAM restorative materials are rapidly developed and widely used in oral aesthetic restoration because of their good biocompatibility and excellent mechanical properties,the success of aesthetic restoration not only depends on the mechanical and physical properties of the materials,but also on their aesthetic properties.Evaluation of the long-term color stability,translucency and surface roughness of aesthetic restorative materials is considered to be the most important factors affecting the outcome and longevity of clinical restoration treatment.However,until now,there is still a scarcity of knowledge about the color stability,translucency and surface roughness of CAD/CAM restorative materials used in dental restorative therapies.Purpose:The purpose of this in vitro study was to compare the effects of artificial saliva and three staining solutions on the color stability,translucency and surface roughness of four CAD/CAM restorative materials,Lava Plus Zirconia,lithium disilicate glass-ceramic IPS E.max CAD,breCAM.BioHpp,and Composite Resin.By this study,the effects of staining solutions on color stability,translucency and surface roughness of all-ceramic and BioHpp materials were evaluated to guide the selection of restorative materials in clinical aesthetic restorative area,especially in anterior teeth area.Methods:There were four different CAD/CAM restorative materials(N=68,diameter 10 mm,thickness 1.5 mm)including Lava Plus Zirconia,lithium disilicate glass-ceramic IPS E.max CAD,breCAM.BioHpp,and Composite Resin.After production by the CAD/CAM technique,these four materials were further processed according to manufacturer instructions,Specifically processed as:Lava and E.max were sintered,veneered with feldspathic porcelain,and glazed;BioHpp was veneered with composite and then polished;and Composite Resin was polished.Four materials were soaked in artificial saliva,coffee,black tea and red wine(n=4)in a 37℃ incubator for 30 days.Before soaking,from specimens of each material,one was randomly selected to make scanning detection.Color parameters L*,a*,and b*were measured with a spectroradiometer against a grey,white,and black background before and after the soaking,and color difference(AE)and relative translucency parameter(RTP)were calculated.In addition,the surface roughness(Ra)of the materials was measured with a laser scanning microscope for shape measurement before and after the soaking.Statistical analysis of AE,RTP and Ra was performed using the analysis of variance and paired t-test(a=0.01),Results:1.There was no statistical significance in the color changes of Lava and E.max specimens caused by soaking in the four solutions(P>0.01),and the color differences△E<3.7 of Lava and E.max specimens were within the clinically acceptable threshold;Composite.Resin and BioHpp specimens which soaked in red wine were found statistically significant in color difference compared with those soaked in artificial saliva,coffee and black tea(P<0.01),and the color differences △E>3.7exceeding the clinically acceptable threshold.2.There were statistically different in translucency among Lava,E.max,Composite Resin whether before or after soaking(P<0.01).There was no significant between before and after soaking of translucency for Lava and E.max materials(P>0.01);There were statistically significant in translucency of Composite Resin brought about by soaking in coffee,black tea and red wine(P<0.01),and the translucency of Composite Resin was decreased.3.There were differences between Lava and Composite Resin in surface roughness whether before or after soaking(P<0.01),no difference between the other materials(P>0.01).After soaking in staining solutions,the surface roughness of Lava,E.max,and BioHpp demonstrated an increasing trend,but the increases were not statistically significant(P>0.01);as for Composite Resin specimens,their roughness was not influenced by artificial saliva,coffee,or black tea(P>0.01),but influenced by red wine(P<0.01).Conclusions:1.Red wine had the greatest impact on the color stability of BioHpp veneered with composite;the color difference of BioHpp and Composite Resin exceeded the clinically acceptable threshold(AE>3.7).2.After soaking in staining solutions,the translucency of Lava and E.max did not change,but Composite Resin decreased.3.After soaking in staining solutions,the surface roughness of Lava,E.max,and BioHpp demonstrated an increasing trend,but this increasing trend was not statistically significant;Composite Resin soaked in red wine had increased roughness,but the roughness was still within the clinically acceptable range(Ra<0.5μm).