Allen W R, Retief D H, Russell C M, Denys F R
Department of Biomaterials, University of Alabama School of Dentistry, UAB Station, Birmingham 35294, USA.
J Dent Assoc S Afr. 1994 Jul;49(7):331-7.
The shear bond strengths of the XR-Bonding System used in conjunction with Herculite composite, to the dentine of forty extracted human permanent first and second molars were determined after the test specimens were stored in physiological saline at 37 degrees C for 48 hours, one week, two weeks and four weeks, respectively. A shear load was applied to the base of the bonded composite cylinders with a knife-edged rod at a crosshead speed of 0.5 mm/minute. The shear bond strengths were expressed in megapascals (MPa). The quantitative microleakage of Class V preparations in dentine (cementum) in forty-eight extracted human maxillary permanent canines restored with the same dentinal bonding system and after storage in physiological saline at 37 degrees C for the same time intervals as for the shear bond strength tests, was determined. On the final day of each time interval the teeth were thermocycled X 500 in a 2 per cent methylene blue solution between 8 degrees C and 50 degrees C with a dwell time of 15 seconds. Microleakage was determined by a spectrophotometric dye-recovery method and expressed in microgram dye/restoration. There was a significant trend for the shear bond strengths to increase with duration of storage (p = 0.01) but the quantitative microleakage was not significantly different (p = 0.75).
在将测试样本分别于37摄氏度的生理盐水中储存48小时、1周、2周和4周后，测定了与Herculite复合材料联合使用的XR-粘结系统与40颗拔除的人类恒牙第一和第二磨牙的牙本质之间的剪切粘结强度。使用刃口杆以0.5毫米/分钟的十字头速度对粘结复合圆柱体的底部施加剪切力。剪切粘结强度以兆帕（MPa）表示。测定了48颗拔除的人类上颌恒尖牙中V类牙本质（牙骨质）预备体在使用相同牙本质粘结系统并在37摄氏度生理盐水中储存与剪切粘结强度测试相同时间间隔后的定量微渗漏情况。在每个时间间隔的最后一天，将牙齿在8摄氏度至50摄氏度的2%亚甲蓝溶液中进行500次热循环，保压时间为15秒。通过分光光度法染料回收法测定微渗漏，并以微克染料/修复体表示。剪切粘结强度有随储存时间延长而增加的显著趋势（p = 0.01），但定量微渗漏无显著差异（p = 0.75）。
