Long-term water sorption of three resin-based restorative materials

Ma’an M. Nayif, BDS, MSc,(a) Abdul-Haq A. Suliman, BDS, MSc, PhD,(b) Toru Nikaido, DDS, PhD,(a) Masaomi Ikeda, BSc, RDT,(a) Richard M. Foxton, BDS, PhD,(c) and Junji Tagami, DDS, PhD(a,d)

(a)Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan, (b)Department of Conservative Dentistry, College of Dentistry, Mosul University, Mosul, Iraq, (c)Division of Conservative Dentistry, Guy’s, King’s and St. Thomas’ Dental Institute, Kings College of London, London, UK, and (d)Center of Excellence Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone, Tokyo Medical and Dental University, Tokyo, Japan

Purpose: To evaluate water sorption of three resin-based restorative materials over 180 days of storage in de-ionized water.
Materials and Methods: Three disks (12.0 mm in diameter and 1.25 mm in thickness) were prepared for each light-cured resin-based material; a polyacid-modified resin composite (élan), an organically modified ceramic (Definite), and a hybrid resin composite (Prodigy). The disks were immersed in de-ionized water at 37�C for 180 days. The weight of the disks was measured at intervals of 1, 7, 14, 60, and 180 days. The results were analyzed using two-way ANOVA followed by the Bonferroni comparison test at 95% level of confidence.
Results: Significant differences (p<0.05) were found among the materials and the storage time. Over 180 days, élan showed earlier and higher water sorption compared with the other materials. Prodigy exhibited the least water sorption over the test period.
Conclusion: Water sorption of the resin-based restorative materials was material and storage time dependent. Prodigy resin composite was the most stable material with the lowest water sorption. (Int Chin J Dent 2005; 5: 1-6.)
Clinical Significance: The polyacid-modified resin composite (élan) showed earlier and higher water sorption behavior than the other materials. It was suggested that undesirable properties might appear subsequent to water sorption.
Key Words: polyacid-modified resin composite, resin composite, water sorption.