二硅酸锂铸瓷牙合贴面在牙列重度磨耗修复中的临床应用

［摘要］ 目的 评价二硅酸锂铸瓷后牙牙合贴面的临床效果。方法 对12例160颗重度磨耗前磨牙和磨牙用二硅酸锂铸瓷进行牙合贴面修复,观察3年,按照美国公共卫生服务修正标准对修复体的颜色匹配、边缘着色、修复体折裂、继发龋及边缘适合度等进行评价。结果 后牙牙合贴面中95.62%的颜色为A级,93.75%的修复体无边缘着色,98.13%的修复体完好无损,所有修复体中没有发现继发龋,95%的修复体边缘适合度为A级。结论 二硅酸锂铸瓷后牙牙合贴面近期临床修复效果优良。     

牙体预备形态对烤瓷贴面复合体抗折强度及断裂模式的影响

目的比较三种牙体预备方法对烤瓷贴面复合体（PVCs）抗折强度及断裂模式的影响。方法分别对离体上颌中切牙进行3种形态（I型、L型、U型）牙体预备，制作长石质烤瓷贴面，树脂黏接剂黏接．用MTS力学实验机测试各牙的断裂载荷值，记录瓷贴面的断裂频数，数据作统计学分析。结果I、L、U三型牙体预备的PVCs与天然牙对照组的断裂载荷值分别为278．61±73．86N（n=9）．295．17±71．76N（n=9），303．42±96．87N（n=8），332．29±60．06N（n=10），经统计学分析四组间断裂载荷值及瓷贴面的断裂模式差别无统计学意义（P〉0．05），3组实验组与对照组的牙体断裂模式差异有统计学意义（P〈0．05）。结论在正中[牙合]瓷贴面间接受力的条件下，采用3种牙体预备设计的PVCs均具有良好的的抗折性能．但烤瓷贴面修复改变了牙体组织在加载条件下的力学特性。     

烧结次数对椅旁计算机辅助设计与制作二硅酸锂玻璃陶瓷贴面不同部位颜色的影响

目的 评价烧结次数和渐变厚度及其交互性对椅旁计算机辅助设计与制作（CAD/CAM）二硅酸锂玻璃陶瓷贴面不同部位颜色的影响。方法 在标准中切牙模型上制备贴面修复模型,用椅旁扫描仪采集光学印模,椅旁CAD/CAM系统制作24个二硅酸锂玻璃陶瓷贴面样本共4组（n=6）,初次结晶组为对照组S0,其余按上釉烧结次数依次为S1、S2、S3组。使用Vita easyshade电子比色仪测定每个贴面的色彩参数L、C、H、a、b,用SAS 9.1.3统计软件采用重复测量多因素方差方法分析不同烧结次数以及不同部位厚度间各颜色指标的差异性。最后扫描电镜（SEM）观察每组贴面的晶体排列和致密度。结果 随着烧结次数增加,试件的L值总体呈减小趋势（P<0.05）。C和b的烧结次数有统计学意义（P<0.05）,其中,除S2组与S3组之间差异无统计学意义外（P>0.05）,其余各组之间的两两比较差异均有统计学意义（P<0.05）。SEM观察发现二硅酸锂晶体随着烧结次数增加,晶体变大,晶体间的孔隙变小,晶体间的锁结变得更为紧密。结论 上釉次数和厚度及其交互性对二硅酸锂玻璃陶瓷的色相、明度、彩度均存在影响。     

2种贴面材料在不同粘接系统下粘接强度的对比研究

目的:比较2种不同贴面材料与3种不同的瓷贴面粘接系统粘接后的粘接强度。方法:应用3种不同的瓷贴面粘接系统(Panavia F、Variolink Veneer、RelyX Veneer),将经过相同处理的离体牙和2种不同的贴面材料(IPS e.max铸瓷和CERAM-AGE聚合瓷)粘接,每组中随机选取一半试件(n=8)37℃水浴24 h,另一半(n=8)冷热循环5 000次后测试其剪切强度,电镜下观察断裂模式。结果:IPS e.max铸瓷组和CERAMAGE聚合瓷组中Variolink Veneer粘接系统在37℃水浴24 h后或5 000次冷热循环后都表现出了最高的粘接强度(P<0.05),所有试件在经过5 000次冷热循环后的粘接强度除Panavia F组外都有明显下降。结论:对于IPS e.max铸瓷和CERAMAGE聚合瓷,Variolink Veneer粘接系统的粘接强度高于Panavia F和RelyXVeneer粘接系统。     

CAD／CAM制作的整体硅酸锂全瓷冠与饰面瓷一氧化锆全瓷冠的比较研究：模拟疲劳试验下的破坏模式与可靠性

目的：本研究的目的在于评估CAD／cAM制作的整体硅酸锂全瓷冠与手工饰瓷的氧化锆全瓷冠的体外疲劳表现和可靠性。材料和方法：利用CAD设计并采用快速成型技术制作下颌磨牙进行全冠预备后的基牙模型,通过CAD／CAM系统分别完成全解剖式的19颗硅酸锂全瓷冠（IPS e.maxCAD）和21颗手工饰瓷的氧化锆全瓷冠（IPS e.max ZirCAD／Ceram）。用树脂粘结材料将上述全瓷冠粘结于前期储存在水中的拟牙本质复合树脂模型上。在模拟口腔运动的疲劳试验中,用半径318mm的碳钨压头从全瓷冠的远颊尖加力并缓慢向舌侧滑动07mm．用三种不同的步进应力方法测试,直到试件发生破坏。当试件出现大块崩瓷或冠折裂时视为失败。如果承受高负载（〉900N）时试件仍未出现失败．则测试方法改变为应力比r呈阶梯式变化的疲劳试验。计算应力水平概率曲线及可靠性。结果：手工饰瓷的氧化锆全冠加载200N负荷完成10万次循环时出现崩瓷,其可靠性〈0．01（0．03～000,双侧90％的可信区间）。在整个步进应力（18万循环,900N）模拟1：3腔运动疲劳试验中未发生CAD／CAM制作的整体硅酸锂全瓷冠的失败,在应力比r的疲劳试验（100万循环．100～1000N）中整体硅酸锂全瓷冠也未见失败。1100～1200N负载可能是阈值范围．硅酸锂全瓷冠出现破坏或折裂。结论：基于目前的疲劳试验结果．CAD／CAM制作的全解剖式硅酸锂全瓷冠具有较高的抗疲劳特性．而手工饰瓷的氧化锆全瓷冠在较低负载的循环试验过程中易出现崩瓷。     

三种二硅酸锂玻璃陶瓷冠抗折强度研究

目的    通过抗折破坏实验分析3种牙科二硅酸锂玻璃陶瓷抗折强度的差异,为国产二硅酸锂玻璃陶瓷临床应用提供依据。方法    将30个下颌第一磨牙标准预备体代型随机分为3组,每组10个,分别制作国产二硅酸锂玻璃陶瓷冠试件（DID组）、IPS e.max CAD冠试件（IPC组）和IPS e.max Press冠试件（IPP组）。3组全瓷冠试件粘接后,分别放置于电子万能试验机上,用直径6 mm圆形加载头,以0.5 mm/min速度垂直加载于全瓷冠面中央至瓷层碎裂,记录最大载荷,即二硅酸锂玻璃陶瓷冠抗折强度。用扫描电镜（SEM）观察表面形态。采用SPSS21.0 统计软件对3组全瓷冠试件抗折强度值进行单因素方差分析和组间两两比较的q检验,检验水准取双侧α = 0.05。结果    3组全瓷冠试件抗折强度结果：DID组为（949.7 ± 119. 4）N,IPC组为（1746.9 ± 244.8）N,IPP组为（2161.8 ± 239.0）N 。3组间总的比较,差异有统计学意义（F = 86.685,P < 0.05）;各组间两两比较,差异亦均有统计学意义（均P < 0.05）。3组全瓷冠试件的断裂模式无显著差异,大部分试件断裂类型均为Ⅰ型。SEM观察,DID组可见晶体在样本中分布不均匀,大小不一,表面有细小裂隙;IPC组可见析出晶体在样本中分布较均匀,晶体较为长大;IPP组可见析出的棒状二硅酸锂晶体均匀分布于玻璃相中,互相嵌合,并形成一种互锁微结构。结论    研究条件下,不同二硅酸锂玻璃陶瓷对抗折强度及断裂类型均有影响,国产二硅酸锂玻璃陶瓷可以满足临床要求,对于其在临床应用有一定指导意义。     

二硅酸锂和白榴石基玻璃陶瓷在模拟咀嚼循环下的耐磨性研究

目的：比较二硅酸锂和白榴石基玻璃陶瓷在模拟咀嚼循环的条件下磨损行为的演变。方法：采用热压铸造技术制备白榴石基玻璃陶瓷（IPS Empress Esthetic ETC1型铸瓷）和二硅酸锂玻璃陶瓷（IPS e．max Press HT型铸瓷）试件,分别与滑石瓷配副,磨损条件为加载力10 N、转速200 r／min,磨损进行100万转次,使用三维形貌扫描仪在每10转万次循环节点测量磨损体积量,扫描电镜观测表面微观形貌。结果：10万转次白榴石基陶瓷磨损量多于二硅酸锂陶瓷,20万至100万转次后两者没有统计学差异。白榴石基陶瓷表面犁沟与碎片剥脱后的粗糙面交错分布,二硅酸锂陶瓷表面以深且宽大的犁沟为主。随着时间的演变,两种陶瓷的犁沟状磨痕逐渐表浅。结论：白榴石基玻璃陶瓷在磨损初期磨损量多于二硅酸锂陶瓷,磨损中后期的磨损量没有显著性差异。     

二硅酸锂玻璃陶瓷在前牙过小牙修复的临床应用

目的 评价二硅酸锂玻璃陶瓷在前牙过小牙修复中的临床应用。方法 对45例患者的87颗牙使用IPS e.max Press铸瓷贴面修复,于修复完成后1、6、12、24、36个月进行复查,参见改良加利福尼亚牙科协会（CDA）/Ryge标准进行评价,检查包括边缘适合性,瓷表面质地,颜色匹配,牙敏感症状和牙龈健康情况五个方面。结果 1个月复查时,11颗基牙出现牙敏感症状,予脱敏治疗处理后症状明显改善。6个月复查牙龈情况,9颗基牙出现牙龈炎症,经卫生宣教及系统牙周治疗后症状好转。1个月及6个月复查时,所有贴面边缘密合,完整性好,瓷表面质地良好。12个月复查时出现1颗贴面完整脱落,清洁处理后重新粘固未再次发生脱落。24个月复查时,一患者进食过程中前牙误咬硬物发生修复体崩折,牙本质暴露,予重新制作贴面进行修复。观察到36个月时7颗基牙出现不同程度龈退缩。结论 二硅酸锂玻璃陶瓷贴面适用于前牙区过小牙修复,可获得良好的临床效果和远期预后。     

安氏Ⅰ类错牙合畸形牙合平面与上气道形态功能及舌骨位置的相关性

目的 探讨安氏Ⅰ类错牙合畸形牙合平面与上气道形态功能与舌骨位置的相关性及其临床意义。方法 随机选取2014年1月—2019年1月治疗的安氏Ⅰ类错牙合畸形牙合患者120例,观察正畸治疗前与治疗3个月时上气道形态功能指标（SNA、SNB、ANB、SPPS、MPS、IPS、S-PNS、Ba-PNS）变化情况;根据牙合平面角度（OP-SN）将患者分为A（35例,10°≤OP-SN<15°）、B（45例,15°≤OP-SN<20°）、C（40例,20°≤OP-SN<25°）3组,观察治疗3个月时3组患者睡眠指标变化[平均血氧饱和度（MSaO₂）、最低血氧饱和度（LSaO₂）、氧减指数、平均脉率]以及牙合平面（OP-SN）、上气道形态功能与舌骨位置（H-PS、H-VPS）变化情况,采用SPSS 20.0软件中的Pearson相关性分析评价牙合平面与上气道形态功能以及与舌骨位置的相关性。结果 正畸治疗后SNA、MPS、IPS、S-PNS、Ba-PNS较治疗前显著升高（P<0.05）,而SNB、ANB、SPPS较治疗前显著下降（P<0.05）;3组不同牙合平面中OP-SN、ANB角随牙合平面角度升高而升高,而SNA、SNB角随牙合平面角度升高而降低,组间差异具有统计学意义（P<0.05）;OP-SN与SNA、SNB呈负相关（P<0.05）,与ANB呈正相关（P<0.05）;SNA、SNB、ANB、SPPS、MPS、TPS上气道形态测量指标与H-PS、H-VPS指标呈正相关（P<0.05）。结论 安氏I类错牙合畸形牙合人群平面与上气道形态功能及舌骨位置密切相关。     

上颌中切牙不同预备形式单端IPS e.max CAD粘接桥的粘接性能研究

目的 研究不同预备形式对上颌中切牙单端IPS e.max CAD粘接桥粘接性能的影响。方法 选取完整离体上颌中切牙32颗,随机分为4组（n=8）,A组：舌侧全覆盖翼板;B组：舌侧翼板占据中切牙舌面中1/2;C组：舌侧翼板远中边缘位于中切牙近远中向1/2;D组：仅邻面翼板。制作IPS e.max CAD单端粘接桥,树脂水门汀粘接,包埋,万能力学试验机测试各组试件的破坏载荷力值并观察破坏模式。结果 A组、B组、C组、D组破坏载荷分别为（199.01±16.46）N、（82.24±9.46）N、（84.67±11.71）N、（61.20±8.41）N。A组破坏载荷力值大于其余三组,差异有统计学意义（P<0.01）,D组破坏载荷力值明显小于A、B、C三组（P<0.01）,B组和C组间无明显差别（P>0.05）。破坏模式以粘接桥脱粘接最多,A组全部伴有牙体折裂。结论 上颌中切牙舌侧翼板完全覆盖型粘接桥具有最佳的粘接性能,能够满足临床需求,但同时易出现基牙牙体折断。     

���ֶ�����﮲����մɹڿ���ǿ���о�

??Objective    To investigate the fracture resistance of different lithium disilicate crowns by mechanical test.  Methods    Totally 30 epoxy dies crowns were divided into 3 groups. They were cemented to domestic lithium disilicate glass-ceramic crowns in Group DID?? to IPS e.max CAD crowns in Group IPC and to IPS e.max Press crowns in Group IPP respectively. Use the universal testing machine to survey the flexural  strength.Stainless steel ball with a diameter of 6 mm was vertically placed on the occlusal surface of the crowns at a speed of 0.5mm/min.Fracture was defined as occurrence of chipping. The loads at fracture were registered??scanning electron microscopy ??SEM?? was used to  observe cross-section morphology. SPSS21.0 was used to analyze the fracture resistance of the three groups??the standard being α = 0.05. Results    The mean fracture resistance of the domestic lithium disilicate glass-ceramic crowns was ??949.7 ± 119.4?? N?? IPC group ??1746.9 ± 244.8?? N?? IPP group ??2161.8 ± 239.0?? N. The difference among the three groups was statistically significant ??F = 86.685??P < 0.05??. The difference had statistical significance ??P < 0.05?? when the groups were compared in pairs. The fracture mode of the three groups of all-ceramic crowns had no significant difference?? and the fracture mode was mostly type ??. Under SEM?? all sizes of crystals with fine cracks on surface could be seen unevenly distributing in samples of group DID?? the big and long crystals could be seen relatively evenly distributing in samples of group IPC??and in group IPP?? the rodlike lithium disilicate crystals were evenly distributed in glass phase?? interdigitated?? and formed an interlocking microstructure. Conclusion    In the study?? different lithium disilicate glass-ceramic crowns have influence on fracture resistance and fracture mode?? and domestic lithium disilicate porcelain can meet the clinical requirement?? which has certain guiding significance for its clinical application.     

Biaxial flexural strength and translucent characteristics of dental lithium disilicate glass ceramics with different translucencies

PurposeThe aim of this study was to evaluate the biaxial flexural strength and translucent characteristics of dental lithium disilicate glass ceramics with different translucencies.MethodsTwo heat pressed lithium disilicate glass ceramics (IPS e.max Press and an experimental ceramic) and one computer aided design/ computer aided manufacture (CAD/CAM) lithium disilicate glass ceramic (IPS e.max CAD) with different translucencies were evaluated. Disk-shaped specimens of each group were subjected to a biaxial flexural strength (BFS) test. Translucent parameters (TP) were also tested at 0.5 mm and 1.0 mm thickness, respectively. X-ray diffraction (XRD) and SEM were used for crystalline and microstructural analysis.ResultsBFS values of two heat pressed lithium disilicate glass ceramics were significantly higher than the CAD/CAM counterpart. No difference in BFS between two heat pressed glass ceramic was found. There were significant differences in BFS and TP values among the tested subgroups with different translucencies for IPS e.max Press and IPS e.max CAD. No difference in crystalline composition was found among the tested glass ceramics, but microstructure with shorter and wider crystal was revealed for IPS e.max CAD ceramics.ConclusionsLithium disilicate glass ceramics with different translucencies demonstrated different BFS and TP values.     

Effect of immediate dentin sealing on load-bearing capacity under accelerated fatigue of thin occlusal veneers made of CAD-CAM glass-ceramic and resin composite material

ObjectiveThe objective of this study was to assess the influence of immediate dentin sealing (IDS) on the fatigue behavior of laminate occlusal veneers fabricated with CAD/CAM lithium disilicate ceramic and resin composite.MethodsForty sound human molars were prepared and randomly divided into 4 groups (n = 10): RC–IDS+ (IDS and resin composite occlusal laminate veneer); RC–IDS- (resin composite occlusal laminate veneer without IDS); LD–IDS+ (IDS and lithium disilicate laminate veneer); LD–IDS- (lithium disilicate occlusal laminate veneer without IDS). The restorations were obtained using a digital workflow. After surface conditioning and bonding, thermocycling and accelerated fatigue tests (20 Hz, 5000 cycles with an initial load of 300 N, step-size of 100 N for 10,000 cycles, up to 1000 N, and then a step-size of 50 N until failure) were conducted. Fatigue data were recorded for both outcomes (crack or fracture) and statistically analyzed. Fractographic and adhesive interface analysis were conducted.ResultsThe indirect resin composite groups showed better fatigue behavior compared to lithium disilicate. IDS only had a positive effect for the survival of resin composite restorations for the ‘fracture’ outcome. Evident presence of micro-gaps at the adhesive interface in the LD–IDS- group could be noted.SignificanceImmediate dentin sealing improved fatigue resistance behavior of resin composite occlusal veneers. However, this effect was not observed in lithium disilicate veneers.     

Internal and marginal adaptation of pressable and computer-aided design/computer-assisted manufacture onlay restorations

The aim of this research was to evaluate internal and marginal adaptation of lithium disilicate partial crowns fabricated using IPS e.max Press and IPS e.max CAD systems. Forty maxillary first molars were divided into two groups. The margins were located above the cementoenamel junction mesially and below it distally. The adaptation of the restoration was evaluated by means of the silicone replica technique. The lowest marginal discrepancy was measured between the preparation margin on the enamel and the IPS e.max Press specimens; the highest discrepancy was observed on the occlusal surface of the IPS e.max CAD specimens. Both systems tested demonstrated acceptable marginal discrepancies in vitro.     

Fracture resistance of monolithic zirconia molar crowns with reduced thickness

Abstract

Objectives. The purpose of the present study was to analyze the relationship between fracture load of monolithic zirconia crowns and axial/occlusal thickness and to evaluate the fracture resistance of monolithic zirconia crowns with reduced thickness in comparison with that of monolithic lithium disilicate crowns with regular thickness. Materials and methods. Monolithic zirconia crowns (Lava Plus Zirconia, 3M/ESPE) with specified axial/occlusal thicknesses and lithium disilicate crowns (IPS e.max press, Ivoclar/Vivadent) with regular thickness were fabricated using a dental CAD/CAM system and a press technique, respectively. The crowns cemented onto dies were loaded until fracture. Based on measurements of the crown thickness made by micro-CT and the fracture load, multiple regression analysis was performed. Results. It was revealed that the occlusal thickness significantly affected the fracture load (p < 0.01), but the axial thickness did not (p = 0.2828). Although the reduction of the occlusal thickness decreased the fracture resistance of the monolithic zirconia crowns, the fracture load of the zirconia crowns with the occlusal thickness of 0.5 mm (5558 ± 522 N) was significantly higher than that of lithium disilicate crowns with an occlusal thickness of 1.5 mm (3147 ± 409 N). Conclusion. Within the limitations of the present study, it is suggested that monolithic zirconia crown with chamfer width of 0.5 mm and occlusal thickness of 0.5 mm can be used in the molar region in terms of fracture resistance.     

Effect of occlusal thickness design on the fracture resistance of endocrowns restored with lithium disilicate ceramic and zirconia

目的 探讨二硅酸锂陶瓷和氧化锆制作的下颌第一磨牙髓腔固位冠的面厚度设计对抗折性能的影响。方法 根据修复设计（冠部材料及厚度）的不同,将24个下颌第一磨牙树脂仿真牙随机分成4组,每组6个。二硅酸锂2 mm组：采用二硅酸锂陶瓷制作修复体,面厚度2 mm,固位体长4 mm;二硅酸锂4 mm组：采用二硅酸锂陶瓷制作修复体,面厚度4 mm,固位体长2 mm;氧化锆2 mm组：采用氧化锆制作修复体,面厚度2 mm,固位体长4 mm;氧化锆4 mm组：采用氧化锆制作修复体,面厚度4 mm,固位体长2 mm。使用树脂水门汀粘接系统（RelyX Ultimate Clicker）粘接后,冷热循环10 000次。将万能试验机与牙长轴呈135°,位移速度0.5 mm·min^-1,在颊尖加载,测定抗折力及折裂方式,并用SPSS 15.0软件进行方差分析和多重比较。结果 二硅酸锂2 mm组、二硅酸锂4 mm组、氧化锆2 mm组、氧化锆4 mm组的抗折力分别为（890.54±83.41）、（2 320.87±728.57）、（2 258.05±557.66）和（3 847.70±495.99）N。氧化锆4 mm组的抗折力最高,二硅酸锂2 mm组的抗折力最低。结论 磨牙髓腔固位冠使用氧化锆较二硅酸锂陶瓷有更高的抗折力,增加修复体面厚度可提高抗折力,但基牙折裂风险也增加。     

2种椅旁CAD/CAM修复材料冠抗折强度的体外研究

目的:比较2 种椅旁CAD/CAM 即刻修复材料(IPS e.max CAD 和Vita Enamic)体外不同面厚度下冠抗折强度的差异,为临床CAD/CAM 修复体的制作提供参考.方法 :定制树脂全冠预备体代型42 个,以面预备量1.5、2.0、2.5 mm 随机分为3 组,CEREC 扫描代型,储存数据,分别利...     

离体下颌前磨牙预备状况与贴面抗折性的关系

目的:旨在比较下颌前磨牙牙体预备和不预备后制备全瓷贴面和复合树脂贴面的抗折力。方法:40个新鲜离体下颌前磨牙随机分为4组(n=10):NPR组(牙体不预备直接0.2 mm厚树脂贴面修复);NPC组(牙体不预备直接0.2 mm厚铸瓷贴面修复);P2C组(牙体预备0.2 mm,修复0.2 mm厚铸瓷贴面);P5C组(牙体预备0.5 mm,修复0.5 mm厚铸瓷贴面),预备面均包绕颊侧延伸颌面1 mm。所有试件常规粘接后进行冷热循环实验(10000次/5~55℃),在万能材料试验机下进行抗折测试(2 KN,0.5 mm/min),断裂面放大10倍分析,数据方差检验。结果:各组抗折力均值分别为:NPR=(690.33±233),NPC=(790.52±408),P2C=(1131.34±341),P5C=(983.56±202)。所有组均有统计学差异(P<0.05),NPR、NPC组抗折力均小于P2C,然后P5C组抗折力与其余各组差距不明显。断裂分析显示断裂面呈现混合断裂(60%),内聚断裂(20%),根裂(15%),粘接断裂(5%)。结论:微量(0.2 mm)的前磨牙牙体预备后修复全瓷贴面可获得最大抗折力,当预备超过0.5 mm时可能会发生牙体折裂。     

基底瓷与饰面瓷厚度配比对IPS e.max全瓷冠断裂载荷的影响

目的:比较不同基底瓷饰面瓷厚度配比对IPS e.max全瓷冠断裂载荷的影响,为临床上全瓷冠的优化设计提供参考依据。方法:加工IPS e.max类似全瓷冠试件,控制咬合面和轴壁总厚度均为1.50 mm,其基底瓷与饰面瓷厚度比分别为1∶4(a组)、1∶2(b组)、1∶1(c组)、2∶1(d组)和4∶1(e组)五组(n=60),应用Hertzian接触实验对试件进行加载,测量试件的断裂载荷并计算其平均值和标准差。结果:1∶4(a)组断裂载荷最小(3 253.13 N),4∶1(e)组最大(5 447.08 N),且随厚度配比比例增加,断裂载荷增大。经方差分析,a、b、c、d、e五组断裂载荷平均值总体差异有统计学意义(P<0.05)。两两比较结果显示:a组与c、d、e组,b组与c、d、e组之间差异有统计学意义(P<0.05);a组与b组之间,c、d、e三组之间差异无统计学意义(P>0.05)。结论:基底瓷饰面瓷厚度配比对IPS e.max全瓷冠断裂载荷有较大影响,且影响IPS e.max双层试件的断裂方式。