PROBLEM TO BE SOLVED: To obtain a dental resin composition which is excellent in antibacterial property and antifouling property, has good safety and storage stability, has high photocurability, and is suitably used for both coating and filling, and the composition. To provide various dental materials having good hardness, strength and durability and capable of maintaining a semi-permanent antibacterial action. An antibacterial dental resin composition containing a quaternary ammonium salt (A) having an unsaturated group having a non-halogen anion and / or an oligomer thereof and a polymer.【課題】抗菌性、防汚性に優れ、安全性及び保存安定性が良好であり、光硬化性が高く、コーティングでも充填でも好適に用いられる歯科用樹脂組成物と、該組成物から得られる良好な硬度、強度と耐久性を有する、半永久的抗菌作用を維持できる各種歯科用材料を提供すること。【解決手段】非ハロゲン系アニオンを有する不飽和基を有する第四級アンモニウム塩（Ａ）及び／又はそのオリゴマー、ポリマーを含有することを特徴とする抗菌性歯科用樹脂組成物。
