Interaction Between Pulpal Dentin Surfaces and Ca-Containing Endodontic Materials

Materials and Methods: Materials were Hypocal (Arch Quixmica), CRCS (Coltene/ Whaldent), CPC cement (experimental), Life (Kerr), and MTA-both white and gray (Tulsa Dental). In extracted first molar following mesial access pulpotomy an occlusal cavity was prepared reaching the pulpal chamber. The entire preparation was filled with one of the materials. The restored teeth, n=3 for each material, were stored in a synthetic tissue fluid (pH=7.2) at 37 º C for 3 m. Teeth (n=2) with occlusal cavities prepared in the above manner but without any restoration served as controls. Following storage, all teeth were sectioned sagitally and polished for examination by SEM and EDXA.

Results: The control pulpal surfaces exhibited mostly open tubules and some localized smear layer. Hypocal was found to be washed away leaving behind a thin adherent Ca-rich layer on the pulpal floor. CRCS resisted erosion and adhered to the dentine. But the adhesion was weak as was evidenced by separation of the material from the dentine due to desiccation. The debonded dentinal surface was found to be sealed due presumably to chelating with eugenol. Both CPC and Life were associated with some erosion but displayed intimate adaptation with and adherence to dentin resulting from the formation of an apatitic layer at respective dentin-material interfaces. In agreement with previous studies (2002 IADR #3156), both MTA bonded chemically to dentinal surface and remained resistant to erosion in the synthetic tissue fluid.

Conclusion: All Ca-containing materials studied demonstrated the ability to seal dentinal tubules. The degree to which they bond to the dentin and their stability in the synthetic tissue fluid were found to be dependent on their composition and structure.