Amer A. Taqa

Abstract

    Aim of the study: Evaluation the flow of a new experimental modeling waxes. Materials and methods: synthesis of one hundred twenty (120) samples of different modeling waxes by mixing different percentages of local natural waxes (hard paraffin, soft paraffin and beeswax) and additives (starch, gum Arabic, rosin and Na-CMC (Na-carboxymethylcellulose)) using mold made from brass according to ADA specification No.24, then measure the flow of them by using vicat apparatus after making modification. Results: The experimental modeling wax (80% hard paraffin+20% soft paraffin) and (80% beeswax+20% soft paraffin) had the most nearest properties to control (Poly wax) at 40°and 45°C and experimental modeling wax (90% beeswax +10% Starch) to control (Major) at 40°C and experimental modeling waxes (80% beeswax+20% hard paraffin), (80% hard paraffin+15% soft paraffin+5% beeswax), (70% hard paraffin+20% soft paraffin+10% Beeswax) and (90% Beeswax+10% Starch) to control (Major) at 45°C. Conclusions: Flow of waxes showed increased with the increasing heating the temperature from 40°C to 45°C. Keywords:Flow, Wax, Vicat apparatus    

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Abstract

Aim: To evaluate the effect of change in time, temperature (increase or decrease) on the degree of conversion and residual monomer release of the vertex heat cured acrylic resin. Material and Methods: The total number of samples (176) were divided into three main groups cured according to ADA and three curing cycles with modifications in time and temperature, degree of conversion and residual monomer properties were measured for all the samples. Results: Analyzed statistically by (Descriptive statistics, ANOVA and Duncan’s multiple range test) and showed that both changes in time and temperature showed significant changes in the degree of conversion, residual monomer. Conclusion: The rapid simplified and regular manufacturer’s instruction curing cycles showed the best results regarding the degree of conversion, residual monomer. Keywords: Temperature, Time, Conversion factor, Acrylic resin.

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