Hamid A, Sutton W, Hume W R
Department of Restorative Dentistry, University of California, San Francisco 94143-0758, USA.
Am J Dent. 1996 Oct;9(5):211-4.
The effects of phosphoric acid concentration and time of dentin treatment on the movement of 2-hydroxyethylmethacrylate (HEMA) from a bonding resin-resin composite combination through dentin were investigated in vitro.
Freshly extracted human third molar teeth were divided into seven groups each of 10 teeth. A closed chamber was attached to the CEJ of each tooth to contain 1 ml distilled water. An occlusal cavity of 6 mm diameter and remaining dentin thickness of 1.0-1.5 mm was prepared in each tooth. Dentin was treated with either 10% phosphoric acid for 15, 30 or 60 seconds or with 37% phosphoric acid for 15, 30 or 60 seconds. A control group not treated with acid was also prepared. The cavities were rinsed, dried and then treated with the HEMA-containing Scotchbond Multi-Purpose bonding resin which was light-cured for 10 seconds. The cavities were then restored with Z100 and light-cured for 30 seconds. Water samples were retrieved from the chambers over a time course (4.32, 14.4, 43.2, 144 & 432 minutes; 1, 3 and 10 days) and analyzed by high performance liquid chromatography.
HEMA was detected in the pulp chambers of all teeth from 4.32 minutes after resin placement. Mean total (cumulative) release at 10 days for all groups was in the 2-4 mumol range. The highest HEMA diffusion rate was 4.32 minutes after placement and were in the range 6-13 times greater than control in the 10%-15 seconds, 10%-30 seconds, 10%-60 seconds, 37%-15 seconds, and 37%-30 seconds groups. Unexpectedly, by far the lowest early rate at 4.32 minutes was in the 37%-60 seconds group (0.6 times of no-acid control).
体外研究磷酸浓度和牙本质处理时间对2-羟乙基甲基丙烯酸酯（HEMA）从粘结树脂-树脂复合体组合通过牙本质移动的影响。
将新鲜拔除的人第三磨牙分为7组，每组10颗牙。在每颗牙的牙釉质牙骨质界（CEJ）处连接一个封闭腔室，内含1 ml蒸馏水。在每颗牙上制备直径6 mm、剩余牙本质厚度为1.0 - 1.5 mm的咬合面洞。牙本质分别用10%磷酸处理15、30或60秒，或用37%磷酸处理15、30或60秒。还制备了未用酸处理的对照组。洞冲洗、干燥后，用含HEMA的Scotchbond多功能粘结树脂处理，光照固化10秒。然后用Z100修复洞并光照固化30秒。在不同时间点（4.32、14.4、43.2、144和432分钟；1、3和10天）从腔室中采集水样，并用高效液相色谱法分析。
树脂放置后4.32分钟，在所有牙齿的髓腔中均检测到HEMA。所有组在10天时的平均总（累积）释放量在2 - 4 μmol范围内。最高的HEMA扩散速率在放置后4.32分钟，在10%-15秒、10%-30秒、10%-60秒、37%-15秒和37%-30秒组中比对照组高6 - 13倍。出乎意料的是，到目前为止，在4.32分钟时最低的早期速率出现在37%-60秒组（为未酸处理对照组的0.6倍）。
