THE EFFECTS OF BARIUM SULFATE AND IODIDE COMPOUND ON THE CHARACTERISTICS OF DENTAL ACRYLIC RESINS

치과용 아크릴릭 레진의 방사선 불투과도에 관한 연구 - 황산바륨과 요오드 화합물 첨가 -

Aspirating or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectible radiopacity with minimal change of mechanical properties and color. The radiopacity, color change(CIE 6..E) and microhardness of acrylic resins were determined after mixing barium sulfate or iodide compound. Thermocycling course was conducted to determine the change of characteristic of resins after using for a long time in the mouth. Five or ten percent of barium sulfate to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic resin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque materials, resin was cured to 20×20×2 mm plate, polished with #600 sand paper and finally polished with Microcloth(Buehler). The specimens were thermocycled in 5 and 55 t distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thcrmocycling. The radiopacity of specimens on the X -ray films was measured with densitometer(X-rite). The color change was detennined with differential colorimeter(Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester(Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, had combined effect on the radiopacity of the dental acrylic resins(p<0.0l). 2. The two variables, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of the dental acrylic resins(p<0.01). But the kinds of acrylic resins did not influence on the color change of mixed dental acrylic resins(p>0.05). 3. Each of the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of dental acrylic resins(p<0.0l). 4. The high radiopaque materials used in this study did not yield clinically usable radiopacity, and the color change was great after mixing those materials.