The aim of the study was to evaluate the biocompatibility of an adhesive sy
stem and a resin component when implanted into connective tissue of rats. F
orty sponges embedded in both materials: Scotchbond MP (SBMP/3M - Group A)
and 2 - hydroxyethyl-methacrylate (HEMA - Group B), were implanted into dor
sal connective tissue of 20 animals. After 7, 15, 30, or 60 days of the imp
lantation, the animals were sacrificed; implant sites were excised and imme
rsed for 24 hours in Kamovisky's fixative. The samples were processed under
routine histologic technique, being stained with H & E. Histological evalu
ation showed that both materials promoted at 7 days intense inflammatory re
sponse with predominance of neutrophils and macrophages. The intense connec
tive reaction was replaced for fibroblastic proliferation associated with m
acrophages and foreign body giant cells over time. The persistent moderate
inflammatory reaction adjacent to scattered fragments of materials was grea
ter to HEMA than to the SBMP. Both experimental materials did not show acce
ptable biocompatibility with connective tissue of rats in spite of allowing
an evident connective tissue healing.