Feldspar Ceramic Strength and The Reinforcing Effect by Adhesive Cementation Under Accelerated Aging

Abstract This study evaluated the effect of the accelerated artificial aging (AAA) on feldspar ceramic strength and the reinforcing effect promoted by adhesive cementation with resin luting agent. One hundred twenty feldspar ceramic disks were obtained. Sixty disks were acid-etched, silanized, and coated with an experimental resin luting agent simulating the adhesive luting procedures. Four groups were created (n=30): uncoated ceramic (control group), uncoated ceramic submitted to AAA, ceramic coated with resin luting agent, and coated ceramic submitted to AAA. Biaxial flexural testing with ball-on-ring setup was carried out. Biaxial flexural strength (s bf , MPa), characteristic strength (s 0 , MPa), and Weibull modulus (m) were calculated for axial positions z=0 (ceramic surface) and z=−t2 (luting agent surface). Data of s bf at positions z=0 and z=-t2 were separately submitted to statistical analyses (a=0.05). The uncoated ceramic submitted to AAA had no significant difference in s bf and s 0 compared with the control group. Resin coating of the ceramic increased s bf and s 0 at z=0. The AAA increased the s bf and s 0 for the resin-coated ceramic specimens at z=0 and also the s 0 at axial position z=-t2. The structural reliability at z=0 and z=-t2 was not influenced by the variables tested. In conclusion, resin coating improved the mechanical strength of the feldspar ceramic. The AAA procedure was not effective in aging the uncoated or resin-coated feldspar ceramic specimens.摘要 本研究评估了加速人工老化（accelerated artificial aging, AAA）对长石陶瓷强度的影响，以及树脂粘接剂（resin luting agent）粘接固位所带来的增强效果。本研究共制备120块长石陶瓷圆盘，其中60块经酸蚀（acid-etched）、硅烷化（silanized）处理后，涂布实验用树脂粘接剂以模拟粘接固位操作流程。实验共设4组（每组n=30）：未涂布陶瓷对照组、经AAA处理的未涂布陶瓷组、涂布树脂粘接剂的陶瓷组，以及经AAA处理的涂布树脂粘接剂陶瓷组。采用球环法装置（ball-on-ring setup）开展双轴弯曲试验（biaxial flexural testing），分别在轴向位置z=0（陶瓷表面）与z=−t2（粘接剂表面）处，计算双轴弯曲强度（biaxial flexural strength, s_bf, MPa）、特征强度（characteristic strength, s₀, MPa）与威布尔模量（Weibull modulus, m）。分别对z=0与z=−t2位置的s_bf数据开展统计学分析，显著性水平设为α=0.05。经AAA处理的未涂布陶瓷组，其s_bf与s₀与对照组无显著性差异。陶瓷表面涂布树脂粘接剂可提升z=0位置的s_bf与s₀。针对涂布树脂粘接剂的陶瓷试件，AAA处理可提升其z=0位置的s_bf与s₀，同时提升其轴向位置z=−t2处的s₀。轴向位置z=0与z=−t2处的结构可靠性不受本次实验变量的影响。综上，树脂涂层可提升长石陶瓷的机械强度。AAA处理对未涂布或涂布树脂涂层的长石陶瓷试件均未起到有效老化作用。