A Study of Light Cured Wax Pattern

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The high viscous light cured wax(HVLW) and the low viscous light cured wax(LVLW) were made experimentally. When it hardens by the irradiation of the 475 nm wave length light, the color of LVLW changes from light green to ocher. There two experimental light cured waxs, conventional inlay waxs and two light cured waxs on the market were tested by the instruction of JIS-6503 or ADA specification No.4. The curing shrinkage and the scratch hardness were also measured.The following results were obtained.1. The light cured waxs are very easy to insert into the prepared cavityby finger pressure, possible to carve the original tooth anatomy in these waxs and at the margins after solldification and have free manipulation time.2. The melted waxs except LVLW vaporized at 500ﾟC have left no solid residue in excess of 0.1% of the original weight when tested according to the instruction of ADA specification No.4.3. The values for flow of the blue and red inlay waxs at 34 to 45ﾟC were increased abruptly and these waxs were thoughrt to reveal comparatively large distortion compared with the low flaw of the light cured wax at these temperature.4. The amount or linear thermal expansion of the light cured waxs is smaller than the conventional blue and red inlay waxs. It is thought to be possible to form and remove the low distortion wax pattern resulted from thermal changes and release or stresses when light cured waxs are used.5. HVLW has a similar touch in carving by the wax carver to the blue inlay wax and this fact is also concluded from the scratch hardness test.6. HVLW showed high shrinkage compared with the conventional blue or red inlay wax. It seems to be difficult to distinguish die material and wax because of its yellow color.Not only the manipulation of the wax but the accuracy of the castings shall be considered. The castings made from these experimental light cured waxs shall be clinically applied to the patients in future.