LABORATORY EVALUATION OF 3 VISIBLE-LIGHT-CURED RESINOUS LINERS

Objectives. The aim of the present study was to evaluate the compositi on and the laboratory performance of three visible light-cured resinou s liners (Cavalite, Ionoseal and Timeline). Methods: Monomers were sep arated from fillers and were analysed by HPLC. Set pastes were analyse d by FTIR spectroscopy and diametral strengths and water solubility we re measured. Results. The monomers identified in the liners were BisEM A/2-HEMA (Cavalite), BisDMA/BisGMA (Ionoseal) and UEDMA (Timeline). Si gnificant variations were found in the filler content but the mechanic al response as assessed by the diametral tensile strength showed no st atistical differences. The curing efficiency ranged from 24.2 to 31.0% (top surfaces) to 26.0-54.0% (bottom surfaces) of remaining C=C bonds . No positive correlations were found between curing efficiency and op tical properties. The bond strength of the liners to dentine was negli gible compared with that to composite. All the liners demonstrated ext ensive gap formation and debonding at the liner-dentine interfaces in marginal adaptation testing. Statistical differences were noticed in t he water absorption and water solubility values of the products. Ionos eal showed extensive hydrolytic degradation compared with the other li ners. No evidence of acid-base reaction was found in the set products. Copyright (C) 1996 Elsevier Science Ltd.