In vivo efficacy of an adhesive system with a self-etching primer incorporating the antibacterial monomer MDPB

在这项研究中，研究了一种新开发的牙本质结合系统的临床效果，该系统采用自蚀刻引物，其中含有5%的抗菌单体MDPB（12-甲基丙烯酰氧十二烷基溴化吡啶），主要是通过比格犬进行体内试验。研究了该引物对人龋牙本质细菌的杀伤活性，结果表明，该引物对龋牙本质细菌的杀灭效果优于专利引物。将变形链球菌接种于犬牙内制备的牙腔，建立了模拟残留细菌牙腔的模型系统。将实验引物或亲本引物涂于牙槽内后采集牙本质样品，测定活菌数量。应用实验引物后，未回收活菌，母引物组细菌回收率显著高于母引物组。用实验引物或母引物对接种变形链球菌的牙槽进行复合树脂修复，并在7天和30天后进行牙髓组织病理学检查。实验引物修复的牙齿在7天的评估期内仅显示出轻微的成牙细胞变化，而用母体引物修复的牙齿则观察到轻微的炎症细胞浸润。7 d后，修复牙体无炎症反应，体内形成1 μm厚的杂化层，并形成树脂标记物。这些结果表明，含MDPB的实验引物在体外和体内均具有抗菌作用、生物相容性和可靠的结合能力，可能有利于临床应用。

In this study, clinical benefit of a newly developed dentin bonding system with a self-etching primer incorporating the antibacterial monomer MDPB(12-methacryloyloxydodecylpyridinium bromide)at 5% were investigated, mainly by in vivo tests using beagle dogs.1. When the killing activities against the bacteria recovered from human carious dentin were investigated, the experimental primer was more bactericidal compared with proprietary prirners.2. The model system simulating the cavity which contain residual bacteria was established by inoculating Streptococcus mutans to the cavity prepared in the tooth of a dog. The dentinal sample was collected after application of the experimental primer or parent primer to the cavity, and the number of viable bacteria was determnined. No viable bacteria were recovered after application of the experimental primer, and the bacterial recovery was signiflcantly greater for the parent primer group. The cavities inoculated with S.mutans were also restored with resin composite using the experimental or parent primer, and the pulp response was histopathologically examined after 7 or 30 days. The teeth restored with the experimental primer showed only slight odontoblastic changes at 7-day evaluation period, although mild infiltration of inflammatory cells was observed for restorations with the parent primer.3. After 7 days, the teeth restored with the experimental primer showed no inflammatory responses, and bonding interfaces with 1 μm-thick hybrid layer and resin tag fomation in vivo.These results indicate that the experimental primer containing MDPB exhibited antibacterial effects, biocompatibility, and reliable bonding abilities not only in vitro but also in vivo, possibly being beneficial for clinical use.