Evaluation of some physical properties of prepared molding wax in comparison to commercial available wax

摘要

Aims: to evaluate the some physical properties (melting range, hardness and thermal expansion) of two prepared mixtures wax contain paraffin oil in comparison with commercial type wax. Materials and Methods: Two mixtures of experimental modeling wax were prepared, mixture No.1 (M1) and mixture No.2 (M2). These two mixtures underwent three physical tests in compare to commercial modeling wax which is a control group, these tests are: 1- Melting range test, 5 capillary tubes were sealed and filled with all type of wax and placed inside electro thermal melting point apparatus.The start of melting wax considered the beginning melting point and when the wax completely became fluid, it is considered the ending melting point. 2 Needle penetration test (hardness test), 5 cylindrical shape samples for each type of wax were prepared and tested for hardness by standard vicate apparatus. 3- Linear thermal expansion, for each type of wax, 5 samples were prepared in a mold , the samples were heated to 25 C° and 40 C° and the distance between reference marks at the lower temperature and the change in length on heating to higher temperature is determined by electronic digital caliper and thermal expansion is calculated as percentage of the total length of sample. Results: Statistical analysis of melting range test showed a significant difference between tested groups in both minimum and maximum melting point. M1 had the higher mean in minimum and maximum melting point. Hardness test analysis showed a significant difference between tested groups, higher mean of hardness was observed in M2, M1 and control group respectively. ANOVA of linear thermal expansion showed a significant difference between groups at 25 C° and at 40 C°. The control group of wax observed the highest mean of thermal expansion at 25 C° and 40 C° than the other two types of wax.Conclusion: The modification of dental wax improved some of the physical properties than commercial one.