Study On Friction And Wear Properties Of Fluorapatite Glass Ceramics,Feldspathic Porcelain And Natural Teeth In Different Environments

Objective:1,Tu study the dental fluorapatite glass ceramic,feldspathic porcelain and natural teeth under the condition of dry friction and lubrication of saliva of friction and wear performance,by studying the clinical commonly used two kinds of veneer porcelain restoration material and friction and wear properties of natural fang enamel,compare the abrasion resistance performances of the two kinds of veneer porcelain itself and the natural tooth wear,and the wear mechanism is discussed in this paper.The purpose of this study is to provide experimental basis for clinical selection of ceramic veneer restorative materials similar to enamel abrasion performance,and to help develop dental restorative materials more suitable for the oral environment in the future.2,Evaluate the effects of saliva and different surface treatments on the friction and wear performance of fluorapatite glass ceramics,as well as the friction and wear performance of fluorapatite glass ceramics and natural teeth under different loads and speeds.Methods:1,Using mmv-1 universal vertical friction and wear testing machine,the zirconia-ceramic veneer double layer samples coated with two kinds of veneer porcelain,ips-emaxcream and Vita vm9,were tested with a size of 20 mm x 20 mm x 4.5 mm.Friction and wear tests were carried out on two kinds of zirconia ceramic samples under dry friction and saliva lubrication respectively under different vertical loads and rotating speeds.2,Using mmv-1 universal vertical friction and wear testing machine,the vertical load is set to 20/40/60 N,the sliding frequency is 50/100/150r/min,and the cycle times are 1500 revolutions.The experimental rotation radius was about 6mm,and 5 samples were selected from each group.Before the test,optical profilometer was used to test the surface morphology and roughness of porcelain surface(Wyko NT9300,Veeco Inc.,Plainview,NY,USA).The porcelain surface was etched with 2.5%hydrofluoric acid for 30 seconds and the surface morphology was recorded by SEM,QUANTA FEG 250.FEI,Hillsboro,OR)were tested with dry rubbing and saliva added.By changing the load size and rotation speed,to understand the friction and wear performance of fluoropatite glass ceramic(ips-emaxcream)and natural teeth after dry friction and the addition of saliva.3,Finally using scanning electron microscopy(sem)and super microscope depth of field and calculate the IPS-emaxcream,Vita vm9 with natural tooth wear surface microscopic morphology and measured with optical three-dimensional contourgraph veneer porcelain wear volume,the 3-d contour instrument with MTS scanning natural teeth before,during,and after wear test sample calculation of natural tooth actual volume loss,and using the computer to determine its dynamic coefficient of friction.4,Statistical analysis:SPSS 17.0 statistical software was used for one-way anova and t test to determine whether there were differences in the friction coefficient and wear amount between the groups,and P<0.05 was considered as significant.Results:1,The dynamic friction coefficient and wear amount of fluorapatite glass ceramics under the condition of saliva lubrication are significantly greater than that under the condition of dry friction;In contrast to fluoropatite glass ceramics,the dynamic friction coefficient and wear rate of feldspar ceramic during dry friction are higher than those under salivary lubrication.Under the condition of dry friction and saliva lubrication,the wear amount of fluoropatite glass ceramics is smaller than that of feldspathic decorative ceramics.Under the condition of saliva lubrication,fluoropatite glass ceramics and corresponding natural teeth showed more serious wear surface than dry friction.Under the condition of dry friction,the wear of feldspathic decorative porcelain and corresponding natural teeth was more serious than that of fluoropatite glass ceramics,and the difference was relatively small under the condition of saliva lubrication.2,After the addition of saliva,the friction coefficient and wear amount between fluorapatite glass ceramics and natural teeth increased significantly,and saliva changed the adhesion and wear mechanism between them.The wear mechanism of saliva environment is the combination of adhesive wear and corrosion wear.In the early stage of fluorapatite glass ceramic and natural tooth wear under dry friction condition,the friction coefficient and wear amount increase with the increase of surface roughness of fluorapatite glass ceramic.Conclusion:1,Compared with feldspar decorative porcelain,fluorapatite glass ceramics and natural teeth show better wear resistance under dry friction conditions,and the addition of saliva can reduce the difference between the two kinds of decorative porcelain.2,After the addition of saliva,the friction coefficient and wear amount between fluoropatite glass ceramics and natural teeth are increased.Saliva can change the wear mechanism of two friction pairs of fluoropatite glass ceramics and natural teeth,increase the adhesion during the friction process between the two contact surfaces,and form a wear mechanism dominated by adhesive wear.In dry friction,the smoother the surface,the better the friction and wear performance of fluorapatite glass ceramics.