Evaluation of the effect of filler size loading, storage condition (wet & dry)‎; and, storage time, on color change of light cured composites

الملخص EN

Objectives: The aim of the present study was to evaluate the effect of filler size loading, storage condition (wet & dry), and storage time on color change of light cured composites.

Methods: A total of 90 disc shaped specimens were fabricated.

The specimens were divided into 3 main groups, 30 specimens each, according to the type of resin-composite used (Te- Econom, Heliomolar and Filtek Supreme).

Each group was further subdivided into three subgroups, 15 specimens each, according to the storage condition to which they were subjected to (S); namely S1 where specimens were stored in a dry dark tight sealed container, and S2 where specimens stored in a wet condition namely; in deionized water contained within a dark bottle.

Each subgroup was further subdivided into three subgroups, 5 specimens each, according to the storage period (P) where P1 denotes for one month storage period, P2 denotes for three months storage period and P3 denotes for six months storage period.

All specimens were stored for 24 hours at room temperature 37 ± 1°C and 100% relative humidity.

All speciemens were treated as previously assigned and then color difference ΔE* was calculated for each sample using the following equation: ΔE* = {(ΔL*) ² + (Δa*) ² + (Δb*) ²} ½ Results: The results of the current study revealed that, for all tested resin-composites, perceptible color change was observed when stored in both conditions, at all assigned periods.

However, the greatest perceptible color change was observed by Filtek Supreme, followed by Te-Econom, and then Heliomolar recorded the lowest values.

Conclusion: Under the conditions of the current study, the following conclusions could be derived: 1- The type of composite has an influence on the color change regardless the storage condition and period.

2- The storage condition strongly influence the color of all tested resin-composites with the wet condition disturbing color more than the dry one, independent of the composite type or the storage period.

3- The storage period has an obvious role on the color changes in all tested materials in spite of the type of composite and the storage condition assigned.