Difference Between Ht Group And Group

910 Words Jun 11th, 2016 4 Pages
We preformed 2-waty ANOVA statically analysis on mean irradiance with p< 0.05. All Pairwise Multiple Comparison Procedures (Holm-Sidak method) show overall significance level = 0.05 (Table III, IV).
The mean irradiance for HT group at the recommended temperature decreases from 331.77 mW/cm2 to 188 mW/cm2 as the tackiness increases from 1 to 2mm. The mean irradiance for LT group decreases from 276.2 mW/cm2 to 121.17 mW/cm2 as the thickness increase from 1 to 2. There are statistically significant differences among the thickness group within the HT group and the same observation is seen in LT group (Fig 11). The result is expected since higher material thickness absorbs more light and result in lower light transmission. More importantly, there is a statistically significant difference between HT group and LT group in all thickness groups, which is indicating a fundament difference in the light transmission between two materials and is discussed later in this thesis (Table V, VI).
Many authors have studies the effect of sample thickness on optical properties on ceramic materials 53, 57, 61-63. Also, many authors propose regression analysis based one the Beer-Lambert law. However, the physical meaning of the regression parameters has never been fully explained 53, 77.

Based on Beer-Lambert law, given a flat surface of IPS e.max® CAD sample which receives an incident irradiance (I0) normal to the surface, if the total reflected irradiance is (Ir), then the irradiance…
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