Comparative Evaluation of Water Absorption, Solubility, Degree of Conversion, and Color Stability in Ormocer-Based and Flowable Bulk-Fill Composites

Objective: This study aimed to evaluate the water absorption, solubility, degree of conversion, and color stability of flowable bulk-fill composites and ormocer-based resin. Materials and Methods: Five flowable bulk-fill composites (SDR, Beautifil Bulk, Omnichroma Flow Bulk, Venus Bulk Fill, Charisma Bulk Flow One) and two composites (Filtek Z250, Admira Fusion 5) were tested (n=40). Color and mass measurements were taken initially, after 24 hours, and after 28 days. Statistical analyses were performed using IBM SPSS V23 and the R program with the WRS2 package. Non-normally distributed data were analyzed using the Kruskal-Wallis H test and Dunn test for post-hoc comparisons, while robust ANOVA with Bonferroni correction was used for group and time comparisons. The significance level was set at p < 0.050. Results: Charisma Bulk Flow had the highest solubility, Admira Fusion 5 the lowest (p=0.02). Degree of conversion and color stability showed significant differences (p