The effect of various retraction materials on color stability of artificial Gingiva and dentine; An in-vitro study

Objectives: The aim of this study is to evaluate the effects of three different retraction agents on the color of dentin and artificial gingiva following the gingival retraction.
Materials and Methods: 36 lower anterior incisors which were embedded in polymethyl-methacrylate resin 3mm below the enamel-cement junction were prepared with a 1.5 mm chamfer finish line. The margin of each sample was waxed 1mm above the enamel-cementum junction and periodontal probe was used to provide the artificial gingival pocket. For each specimen, silicone indexes were prepared to make an artificialgingiva. Following the removal of the waxes, 3 mm artificial gingiva was created by a silicone material. Then three different retractionmethods (Retraction cord + %25 aluminum chloride, retraction cord + %20 ferricsulphate and retraction paste including 15% aluminum chloride) were applied for 180 seconds and then rinsed for 30 seconds. Retraction materials were completely removed from the specimens surfaces. Color measurements were applied before and after the retraction by Easy shade device from three points of buccal surfaces that were indicated before the retraction. Polymethyl-methacrylate block was used for calibration of the Easy Shade device. After the calculation of ΔE values, the discoloration of the dentine and artificial gingiva was determined. Data were analyzed using one-way ANOVA and Tukey honestly significant difference (HSD) test (a=.05).
Results: For the artificialgingiva, application of the retraction paste showed statistically lowest values in comparison to the other methods P(sig.):0,00<0,01). For the dentine, retraction cord + %25 aluminum chloride showed statistically significant lower ∆E values in comparison to retraction cord + %20 ferricsulphate, but application of the retraction paste including %15 aluminum chloride did not show statistically significant difference compared to the other methods.
Conclusion: The retraction solutions containing ferric sulphate caused discoloration both in dentineand also in the gingiva.