Smith S John S, McCord J Fraser, Macfarlane Tatiana V
The University Dental Hospital of Manchester, Manchester, United Kingdom.
J Prosthet Dent. 2002 Oct;88(4):423-30. doi: 10.1067/mpr.2002.128746.
Little evidence is available on the length of time that adhesive should be allowed to dry before irreversible hydrocolloid impression making.
This study investigated the effect of adhesive drying times on the bond strengths of 2 irreversible hydrocolloid impression materials to 2 "custom" tray materials.
A total of 1,632 specimens were tested: 816 in tensile tests and 816 in tests of the shear bond strength (megapascals) of 2 irreversible hydrocolloid impression materials to an autopolymerizing and a visible light-polymerizing acrylic resin tray material. In the first part of the investigation, a single coat of adhesive was applied to specimen plates that simulated the custom impression tray surface; in the second part, a second coat of adhesive was applied after the irreversible hydrocolloid was removed, and the effect of this second coating on bond strength was examined. In both parts, the adhesive was allowed to dry for a range of times (0 to 8 minutes at 30-second intervals, for a total of 17 time periods) before the addition of the impression material. The specimen plates were placed in a humidor and separated in a universal testing machine operated at a crosshead speed of 100 mm/min with 0- to 5-kN load cell. Data from each of the 1,632 specimens were collected and evaluated with analysis of variance, regression analysis, and t tests (P<.05).
Significant differences in mean bond strengths were found between specimens with a 4-minute adhesive drying time (0.179 MPa tensile, 0.068 MPa shear) and specimens with a 0-minute drying time (0.065 MPa tensile, 0.015 MPa shear). Any period over 4 minutes produced no significant difference. The mean bond strengths of the single-coated specimens were 0.179 MPa (tensile) and 0.076 MPa (shear). These values were significantly greater than those for specimens with a second adhesive layer (0.136 MPa tensile, 0.035 MPa shear) over all time periods. Mean tensile bond strengths (0.158 MPa) were consistently higher than shear bond strengths (0.056 MPa) for all combinations of tray material, adhesive application, and time.
Within the limitations of this study, the results suggest that adhesive applied to the autopolymerized and light-polymerized custom tray materials tested should be allowed to dry for at least 4 minutes before irreversible hydrocolloid is applied. Better results were obtained when the adhesive layer from a failed irreversible hydrocolloid impression was removed and replaced rather than overlaid with an additional adhesive coating.
关于在制作不可逆水胶体印模之前，粘合剂应干燥多长时间，目前几乎没有相关证据。
本研究调查了粘合剂干燥时间对两种不可逆水胶体印模材料与两种“定制”托盘材料之间粘结强度的影响。
共测试了1632个样本：816个用于拉伸试验，816个用于测试两种不可逆水胶体印模材料与自凝和可见光固化丙烯酸树脂托盘材料之间的剪切粘结强度（兆帕）。在研究的第一部分，在模拟定制印模托盘表面的样本板上涂一层粘合剂；在第二部分，去除不可逆水胶体后再涂一层粘合剂，并检查这第二层涂层对粘结强度的影响。在这两部分中，在添加印模材料之前，让粘合剂干燥一系列时间（每隔30秒干燥0至8分钟，共17个时间段）。将样本板放入保湿箱中，并在万能试验机中分离，试验机的十字头速度为每分钟
100 毫米，配有0至5千牛的测力传感器。收集并评估1632个样本中每个样本的数据，采用方差分析、回归分析和t检验（P<0.05）。
粘合剂干燥4分钟的样本（拉伸强度0.179兆帕，剪切强度0.068兆帕）与干燥0分钟的样本（拉伸强度0.065兆帕，剪切强度0.015兆帕）之间的平均粘结强度存在显著差异。超过4分钟的任何时间段均未产生显著差异。单涂层样本的平均粘结强度为拉伸强度0.179兆帕，剪切强度0.076兆帕。在所有时间段内，这些值均显著高于有第二层粘合剂涂层的样本（拉伸强度0.136兆帕，剪切强度0.035兆帕）。对于托盘材料、粘合剂应用和时间的所有组合，平均拉伸粘结强度（0.158兆帕）始终高于剪切粘结强度（0.056兆帕）。
在本研究的局限性范围内，结果表明，在应用不可逆水胶体之前，涂覆在测试的自凝和光固化定制托盘材料上的粘合剂应至少干燥4分钟。当去除并更换失败的不可逆水胶体印模上的粘合剂层，而不是再涂一层额外的粘合剂涂层时，可获得更好的结果。
