Monkey pulp reactions to restorative materials.

Deep buccal cavities in 99 teeth in eight young monkeys were filled with the following combination of materials: a light-cured microfilled composite with or without a base, a chemically cured composite with a base, a silicate cement, and a zinc oxide-eugenol cement. The acid etch technique and intermediate layer of resin was used in the composite group. Pulp reactions and presence and location of bacteria were studied after 8 days and after 90 days. In the short observation period the inflammatory reactions were more pronounced when unlined composite fillings were evaluated compared with silicate cement fillings and with lined fillings. Bacteria were seen in all unlined cavities and a significant association between presence of bacteria and moderate to severe inflammatory responses was found. The most severe inflammatory reactions were seen when bacteria were found in the dentinal tubules. After 90 days slight inflammatory changes prevailed in all groups. A significant correlation between bacteria and inflammatory reactions could still be observed.