Influence of acidic monomer on polymerization of dual-curing resin cements

研究了自蚀刻底漆（SEP）中酸性单体对自蚀刻底漆作为牙齿调节剂的双固化树脂水泥（RC）聚合的影响。研究了四种不同成分的商用胶粘剂体系。通过改变SEP处理时间（10s或30s）、光照或不光照（光固化或自固化），测定RC与牛牙本质和丙烯酸树脂板（PMMA）的剪切结合强度，以估计RC的聚合程度。测定了各SEP在牛牙本质表面的pH值变化，以估计酸性单体的残留量。不同产品的sep混合后的pH值在1.5 ~ 3.3之间存在差异。应用于牙本质表面的sep在施用5分钟后，pH值仅上升0.3 ~ 4.5左右。结果表明，在RC的作用下，SEP处理后的牙本质表面仍有较好的酸性单体残留。对于任何粘结体系，SEP的处理时间和RC的固化方式对其与牙本质的粘结强度均无显著影响。然而，对于两种胶粘剂体系，自固化样品与PMMA的结合强度明显低于光固化样品。此外，当使用树脂嵌体光固化处理剂代替每种SEP进行PMMA预处理时，所有rc的自固化样品的结合强度都明显低于光固化样品，并且两种rc在自固化模式下几乎没有与PMMA结合。上述结果表明，每种SEP中所含的酸性单体都会影响RC的自固化方式，可以在SEP中加入自固化的二次催化剂来加速两种产物的树脂水泥聚合。

The purpose of this study was to examine the influences of acidic monomer included in self etching primer (SEP) on polymerization of dual-curing resin cement (RC) which uses a SEP as tooth conditioner. Four commercial adhesive systems with different composition were investigated. The shear bond strengths of these RCs to bovine dentin and acrylic resin plate (PMMA) were measured, changing the treating time of SEP(10s or 30s) and with or without light-irradiation to RC(light-curing or self curing mode, respectively), to estimate the degree of polymerization of RC. The change of pH value of each SEP applied on bovine dentin surface was also measured to estimate the residue of acidic monomer.The pH values of SEPs immediately after mixing were different among products in the range of 1.5〜3.3. The pH values of SEPs applied on dentin surface only rose about 0.3〜4.5 even five minutes after application. This result suggested that the acidic monomers still remained fairly on dentin surface treated with SEP at application of RC.The bond strength to dentin was not significantly influenced with the treating time of SEP and the curing mode of RC for any adhesive system. Regarding the bonding to PMMA, however the self Cured samples showed significant lower bond strengths than the light-cured samples for two adhesive systems. Moreover when the light-curing primer for resin inlay was used instead of each SEP on pre-treating of PMMA, the bond strengths of self cured samples were significantly lower than that of light-cured samples for all the RCs used, and two RCs did not almost bond to PMMA in self curing mode.These results suggested that acidic monomer included in each SEP could influence on the self curing mode of the RC and a secondary catalyst for the self curing might be added into the SEP to accelerate polymerization of the resin cement for two products.