SummaryThe present study investigated the development of crown and bridge resin using a new PNC-EMA monomer. M MA monomer has long been used for crown and bridge resins, but the polymer prepared with MMA monomer has certain demerits such as low mechanical strength and abrasion resistance. The authors prepared a polymer by mixing 3PNC-EMA monomer having a P=N bond in its skeleton, previously synthesized by ANZAI et al., with a monomer currently available the compressive strength and hardness increased in accordance with increased amounts of the mixed 3PNC-EMA monomer, but water sorption reached 1.86 mg/cm2 when the mixed amount of 3PNC-EMA was 28%. The degree of abrasion decreased in accordance with the increase in the mixed amount of 3PNC-EMA, showing a value 1/3 that of PM MA, when mixed in a proportion of 70%.