Reactions of connective tissue to compomers, composite and amalgam root-end filling materials

To evaluate the subcutaneous connective tissue reaction to compomers, composite and amalgam root-end filling materials.

This study was conducted in 30 Wistar albino rats. The materials were mixed or light-cured according to the manufacturer's directions and placed in polyethylene tubes. Group 1 - Dyract compomer (Dentsply); group 2 - F2000 compomer (3M); group 3 - Valux Plus composite (3M); group 4 - Oralloy high-copper amalgam (Coltene). The tubes containing the materials were implanted into the dorsal connective tissue of rats, which were killed 7, 15, 30, 60 and 90 days after the implantation procedure. Thirty extra empty tubes were also placed as controls. The implant sites were excised and prepared for histological evaluation. Sections of 6-microm thickness were stained with haematoxylin and eosin and assessed under light microscopy. The presence of inflammation, predominant cell type and thickness of fibrous connective tissue adjacent to each implant were recorded. Reactions were scored as: 0: none or few cells and no reaction; 1: less than 25 cells and mild reaction; 2: between 25 and 125 cells and moderate reaction; 3: 125 and more cells and severe reaction. Fibrous capsules were considered to be thin if their thickness was less than 150 microm and thick if it was more than 150 microm. Necrosis and formation of calcification were categorized as 'yes' or 'no'.

All four materials caused moderate or severe inflammatory reactions in the first 7-day period, but these reactions decreased by the 60th and 90th days. No significant difference in inflammatory cell numbers between the materials could be detected at the 90th day.

Valux Plus composite, Dyract and F2000 compomers and Oralloy amalgam were biocompatible.