A new visible light-cured composite resin, Fotofil, has been developed for the esthetic restoration of anterior teeth. The pulpal responses elicited by this material in unlined cavities and cavities lined with Dycal were compared with those elicited by a negative control consisting of modified zinc oxide-eugenol cement Notebec and a silicate cement Syntrex. The pulpal responses were evaluated in the permanent maxillary and mandibular incisors in vervet monkeys using labial Claterial in each monkey. Groups of 10 monkeys were killed at intervals of 2 days, and 2 and 8 weeks after restoration of the teeth. The most severe pulpal responses were elicited by the unlined Fotofil and Syntrex restorations at all three time intervals. The Dycal lined Fotofil restorations elicited a milder pulp response than the Nobetec at 2 days and 2 weeks. No pulpal response was elicited by the latter two materials at 8 weeks. These results clearly showed that Fotofil and Syntrex are irritant to the dental pulp up to 8 weeks. The placement of a Dycal liner beneath Fotofil restorations reduced the pulpal irritation elicited by this material to levels which were lower than those elicited by the Nobetec control at 2 days and 2 weeks.