The Study On The Physical Properties Of A Dental Base Resin Cured With A New Developed Dental Base Resin Cooker

Methyl methacrylate (MMA) dental base resin was the most frequently used clinical dental base resin because of its good physical, chemical, mechanical and biological properties. Heat treatment was an indispensable step in the manufacturing of dentures with MMA base. The aim of this study was to develop, research and improve the synthesis techniques of MMA dental base resin, and to study the physical properties of the dental base resin cured with a new developed dental base resin cooker. The transverse flection, flexural strength, elastic modulus, impact strength and surface hardness of dental base resin were examined and compared, cured with the fast automatic dental resin hydraulic pressure cooker (FADRHPC), the multipurpose dental resin air-pressure cooker (MDRAPC) and the conventional water bath cooker (CWBC). The horseshoes shape mould was used to simulate edentulous jaw's dental alveoli crista, which could partly directly reflect the transformation tendency of dentures, and on which their line shrink and volume change level could be examined and calculated. To utilize the FADRHPC, this technique and the CWBC were used and evaluated to make complicated dentures (teeth missing both side), clinical adjusted occlusion height of the dentures were measured at the same time.The experiment results showed that:1. The physical properties including the transverse flection, flexural strength,impact strength and surface hardness results showed that there were no significant differences between three groups (P>0.05), but there was a significant difference in the transverse flection between the FADRHPC and the CWBC (P<0.05), which illustrated that the tenacity of dental base resin cured with the FADRHPC was better than that of the CWBC.2. To simulate edentulous jaw, the volume stability of the horseshoes shape test specimens were compared respectively, cured with the FADRHPC, the MDRAPC and the CWBC, the result showed that there were no significant differences between three groups (P>0.05) .3. The properties of PMMA dentures cured with the FADRHPC and the CWBC were examined and compared. The results showed that both the two techniques could produce satisfying dentures, and the FADRHPC had following good qualities comparing to the CWBC. (1) It could greatly shorten the heat treatment time, and raise efficiency. (2) It could greatly shorten the clinical diagnosing time and raise the clinical work efficiency because of less occlusion adjusting was needed in clinical. (3) Sanitation, it could save energy and eliminate the influences on environment from steam. (4) It could accomplish automatically in the whole process. Comparing with the MDRAPC, it could largely decrease the volume and weight of the device, and need not additional air compressor to compress, so it could greatly cut down the cost and had better furthermore clinical spread value.