Deliperi Simone, Bardwell David N, Papathanasiou Aikaterini, Perry Ronald
Tufts University School of Dental Medicine, Boston, MA, USA.
Am J Dent. 2003 Oct;16(5):351-5.
To evaluate the efficacy of differing resin based liner materials in reducing microleakage.
80 freshly extracted caries-free human premolars and molars were used. MO/DO Class II standardized preparations were performed with the gingival margin placed 1 mm above the CEJ. Teeth were randomly divided into two groups; each one was divided into four subgroups (A-B-C-D for Group 1 and E-F-G-H for Group 2). Each prepared tooth was etched with 32% H3PO4 (Uni Etch); in Group 1, one coat of One Step and in Group 2, two coats and two cures of Prime & Bond NT adhesives were applied. In each group 1 mm layer of three different liners was used: A2 Heliomolar RO for A and E; A2 Heliomolar Flow for B and F; A2 Bisfil 2B for C and G. No liner was used for D and H subgroups. Teeth were then restored using 2 mm increments of Pyramid A2 Dentin and A1 Enamel and cured with a VIP curing light. Teeth were thermocycled x500 between 5 degrees C and 55 degrees C with a dwell of 30 seconds and then placed in a 0.5% methylene blue dye solution for 24 hours at 37 degrees C. Samples were sectioned longitudinally and evaluated for microleakage at the gingival margin under a stereomicroscope at x20 magnification. Dye penetration was scored using an Ordinal Scoring System where 0= no penetration; 1= enamel penetration; and 2= dentin penetration.
A Chi Square Test revealed a statistically significant difference between Group 1 and Groups 2 (P < 0.001). Group 1 yielded the most microleakage. No statistically significant difference was noted between the subgroups of each group; a statistically significant difference of B and D vs. E and H (P < 0.01 > 0.001) and B vs. G and D (P < 0.05 > 0.01) was also noted. The dentin bonding agent in Group 2 contributed to a reduction of microleakage when compared to Group 1.
评估不同树脂类衬层材料在减少微渗漏方面的效果。
使用80颗新拔除的无龋人类前磨牙和磨牙。制备MO/DO II类标准洞形，龈缘位于釉牙骨质界上方1mm处。牙齿随机分为两组；每组再分为四个亚组（第1组为A - B - C - D，第2组为E - F - G - H）。每颗制备好的牙齿用32%的H3PO4（优酸蚀剂）酸蚀；第1组涂一层一步法粘结剂，第2组涂两层并光照固化两次的全酸蚀粘结剂（Prime & Bond NT）。每组使用三种不同衬层材料各1mm厚：A和E组用A2光固化复合树脂（Heliomolar RO）；B和F组用A2流动树脂（Heliomolar Flow）；C和G组用A2双固化复合树脂（Bisfil 2B）。D和H亚组不使用衬层材料。然后用2mm厚的金字塔A2型牙本质和A1型釉质材料修复牙齿，并用VIP光固化灯固化。牙齿在5℃至55℃之间进行500次热循环，每次保持30秒，然后置于37℃的0.5%亚甲蓝染料溶液中24小时。样本沿纵向切开，在20倍体视显微镜下评估龈缘处的微渗漏情况。使用序数评分系统对染料渗透情况进行评分，0 = 无渗透；1 = 釉质渗透；2 = 牙本质渗透。
卡方检验显示第1组和第2组之间存在统计学显著差异（P < 0.001）。第1组产生的微渗漏最多。每组亚组之间未发现统计学显著差异；还发现B和D组与E和H组之间（P < 0.01 > 0.001）以及B组与G和D组之间（P < 0.05 > 0.01）存在统计学显著差异。与第1组相比，第2组的牙本质粘结剂有助于减少微渗漏。
