功能单体结构对口腔正畸胶粘剂性能的影响

Influence of functional monomer structure on performance of orthodontics adhesive

制备了一种口腔正畸胶粘剂,并研究了功能单体结构对其性能的影响。功能单体二甲基丙烯酸乙氧基均苯四甲酸酯(PMDM)结构中含有双甲基丙烯酸酯可聚合基团、双粘接性羧基及强极性羟基基团。研究结果表明,随着PMDM含量的增加,羧基浓度增加,胶粘剂的粘接强度也随之增大;当w(PMDM)=10%时,剪切强度达最大值(20.81MPa);与传统功能单体4-甲基丙烯酰氧乙基偏苯三酸酐(4-META)相比,PMDM的优点是可以通过聚合基团引发交联反应,并且易溶于基质树脂中,从而减少了稀释剂的用量,胶粘剂固化物的硬度提高至90.37N/mm2;PMDM中的极性基团可与填料羟基磷灰石(HAP)中的羟基形成次价键,从而提高了基质树脂与HAP的界面粘接力,使胶粘剂与牙釉质之间的破坏方式为粘接破坏,有利于正畸托槽的摘除。

A dental orthodontics adhesive was prepared,and the influences of functional monomer structure on performance of orthodontics adhesive were investigated. The pyromellitic dimethacrylate（PMDM） was used as a functional monomer which contains dimethacrylate polymeric groups,double cohesiveness carboxyl groups and strong polar hydroxyl groups. The research results showed that the bonding strength of orthodontics adhesive was increased with increase of PMDM content or carboxyl consistence, the maximal shear strength was 20.81 MPa when mass fraction of PMDM was 10%. Comparing with the conventional monofunctional methacrylate monomer 4-META,PMDM can trigger crosslink reaction through polymeric groups and can easily be dissolved in the matrix resin,so thinner content was reduced and hardness of adhesive was increased to 90.37 N/mm^2. The interface bonding strength between matrix resin and inorganic filler hydroxyapatite （HAP） could be improved because the secondary valence bond between polar groups in PMDM and hydroxyl in HAP was formed, so the breakage mode between adhesive and enamel was bonding breakage and it was propitious to extirpate orthodontics brackets.