Experimental Study On Simultaneous Repair Of Tetracyclic Dental With ZrO Page 2 Phenomenon By Different Resin Adhesives

Aesthetics are important evaluation criteria discolored teeth cosmetic restoration, andchroma repaired to ensure its aesthetic is the first condition.However restore the color andbrightness of discolored teeth has become the patient’s goals and aspirations of the majority ofdentists,especiallythegroup ofpeopleaffectedbytetracycline.In recent years,ZrO2ceramic materials are rapidly developing of all-ceramic materials,which meet all of the performance of all-ceramic materials, but also they are better than otherall-ceramic materials in strength, toughness, etc.To the teeth are deeply infected by tetracyclinefamily of drugs and depth of discolored teeth dead dental pulp, subject to the ability ofporcelain veneers to mask the impact of certain factors and limitations, can not achievesatisfactory results.Some scholars have found the ultimate color of porcelain veneers can beapplied as an adhesive resin cement to adjust in order to achieve the aesthetic effect of patientsatisfaction. Due to the different masking properties of the resin cements, resin cements itselfmay have an impact on the final color restoration.However one of most important factor in thesuccessof theporcelainveneer restorationsand adhesivewhichisbond strength.ObjectiveZrO2ceramic veneer repair to simulate two different levels of tetracycline colored by X-Rite MA68II computer colorimeter observe color effects of the four colors of Kerr NX3light-cured resin cements and SDI dual-cure resin cement in experiment, and to test shear strength oftwo adhesive system by Universal test equipment and TC-501F cold cycler.To elect resincement that not only the color,but also the mechanical properties are matched by tetracycline ofpatients which achieve satisfaction tooth color with ZrO2porcelain veneer restorations, toprovidereferenceforclinicalpracticedoctor.Methods:1.In experiment,according to the different simulation tetracycline backgrounds (light grayand dark gray group group), in accordance with the principles of the completely randomized80tiles into two large groups; Depending on the resin binder, turn each large group were randomlydivided into four groups, a total of eight teams, each team10specimens.The two kinds of thesimulate tetracycline were used to bond by white and transparent color Kerr NX3light-curedresin cements, A1and A3SDI dual cure resin cement, with X-Rite MA68II computercolorimeter were measured totest the surface L*a*b*that before ZrO2porcelain veneers piece bonded (control group) and after two ZrO2porcelain veneers bonded and the color values (ΔE)between ZrO2porcelain veneers before bonding and in each group after bonding, according tothe International Commission on illumination (CIE) were evaluated in1976L*a*b standardcolorimetricsystem.2.The ZrO2porcelain veneers are embedded with ultra-anhydrite and prepare high as2mm,a length of9mm, a width6mmof each rectangular resin block of each of the20were randomlydivided into A, B two groups of10specimens. A group on the adhesive surface of eachspecimen etching, cleaning, drying, dry coupling with Kerr NX3light-cured adhesive resincements; group B bonded surfaces of the coupling agent applied to the specimen, drying, andthen SDI dual cure resin cement bonding. Then from the A, B groups each selected fivespecimens be5~55℃thermal cycling10,000times. With a universal testing machine todetectthe specimenshearstrengthofresincements.Results1.1Use NX3light-cured resin cements and SDI dual-cure resin cement bonding porcelainveneer which repair simulation of tetracycline teeth, before and after the bond of ZrO2porcelain veneer specimens there was statistically significant difference between the surface L*,a*, b*value(P <0.05).1.2The same kind of adhesive resin cements, the L*value of light gray set higher thangray group. With Kerr NX3white light-curing L*value of the difference between the controlgroup was not statistically significant (P>0.05), the difference between the rest of the group andthecontrol group werestatisticallysignificant(P <0.05).1.3Tetracycline under dark gray background,only Kerr NX3white light cured group,before and after bonding color values of porcelain veneer pieces surface color are△E <1.5,noteasyto identifywiththenaked eye.1.4Tetracycline under light gray background,Kerr NX3white light cured group, SDIA1dual curing group and SDI A3dual curing group,before and after bonding color values ofporcelain veneer pieces surface color are△E <1.5,and between each experimental groupcompared the three groups of color, the color difference between the compared values Delta E <1.5.2.1No thermal cycles before treatment A: Kerr NX3resin cement group and B:SDI resincementspecimens ofshearbondstrength valueshadsignificantdifference(P<0.05)2.2After thermal cycling treatment, Kerr NX3resin cement group and B:SDI resin cement groupspecimens ofshearbond strength values werenot statisticallydifferent(P>0.05).2.3A, B groups in each respective bonding shear strength values before and after thermalcyclingthedifferencewas notstatisticallysignificant(P>0.05).Conclusion1.Tetracycline teeth under dark gray background with Kerr NX3white light-cured resincementtorepairthebody’s colorbetter2.Tetracycline teeth under light gray background with SDI A1dual cure resin cement canwellreflecttheeffectofthefinalrestoration prosthesis.3.The bond strength of Kerr NX3resin cement bonding system stronger than SDI adhesiveresincementssystem,able tomeettheclinicalrequirements.