SYNOPSIS
The aim of this study was to investigate the effect of bioabsorbable material on the direct pulp capping to know whether this material has a function in dentin regen-eration by bioabsorption.
Class V cavities with the exposed pulp area were prepared on the buccal surface of first molars in young beagle dogs. All cavities were conditioned with a self-etching primer (Clearfil SE Primer). In the cavities of right side (experimental group), the exposed pulp was covered with a bioabsorbable sheet (Kurabio AG), and then the cavities were coated with an adhesive agent (Clearfil SE Bond) and resorted with a resin composite. The left side cavities (control group) were applied the adhesive agent without the bioabsorbable sheet and restored with a resin composite. On three and six months after surgery, the teeth were extracted, im-mersion-fixed and decalcified. Afterward, the teeth were frozen-sectioned, stained with hematoxylin and eosin and observed using a light microscopy.
In the experimental group, a large amount of the tertiary dentin was formed into the prepared cavity. On the other hand, the tertiary dentin was almost not formed into the cavity in the control group.
The significantly tertiary dentin formation was recognized into the prepared cavity when the exposed pulp area had been covered by a bioabsorbable material. This result suggested that the space making by a bioabsorbable material could produce the derivation of pulp tissue and then dentin regeneration into the pre-pared cavity.

Key words:bioabsorbable material, tertiary dentin, regeneration, direct pulp capping