Histopathological Evaluation of Subcutaneous Tissue Reaction in Mice to a Calcium Hydroxide Paste Developed for Root Canal Fillings

Abstract

We aimed to evaluate the subcutaneous tissue reaction to a new calcium hydroxide paste for root canal fillings developed by Neo Dental Chemical Products Co., Tokyo, Japan. We injected calcium hydroxide paste and a water-based control subcutaneously into the dorsal area of 6-week-old anaesthetized male ddY mice. The tissue surrounding the injection sites was removed from mice in each group, 2 days, 1 week, 3 weeks and 12 weeks after the injection, and histopathologically examined. We found necrotic and degenerative changes, as well as foreign body reaction or proliferation of granulation tissue in specimens from both groups until 3 weeks after the injection. Some lymphocyte infiltration was observed in the 12-week specimens of the control group only. We conclude that calcium hydroxide paste is safe to use as a root canal filling material.

Keywords

Tissue reaction Histopathological evaluation Calcium hydroxide Root canal filling material Polyethylene glycol

References

Kawakami

Mizoguchi

Matsuura

Shimizu

Kurihara

Ito

: Histopathological safety evaluation of polyethylene glycol applied subcutaneously in mice. J Int Med Res 2004; 32: 66–69.

International Organization for Standardization (ISO) : Biological Evaluation of Medical Devices — Part 6: Test for Local Effects after Implantation (ISO 10993-6: 1994). Geneva, Switzerland: ISO, 1994.

Kawakami

Nakamura

Hasegawa

Akahane

Eda

: Ultrastructural study of initial calcification in the rat subcutaneous tissue elicited by root canal filling material. Oral Surg Oral Med Oral Pathol 1987; 63: 360–365.

Metin

Aktoren

Olgac

: Histopathological evaluation of root canal filling materials. J Dent Res 2003; 82: B-299.

Tanzilli

Nevins

Borden

: The reaction of rat connective tissue to polyethylene tube implants filled with Hydron or gutta-percha. Oral Surg Oral Med Oral Pathol 1983; 55: 507–513.

Erausquin

Muruzabal

: Tissue reaction to root canal filling with absorbable paste. Oral Surg Oral Med Oral Pathol 1969; 28: 567–578.

Ochiai

Shimizu

Kurihara

Hasegawa

Kawakami

: Tissue reaction to the calcium hydroxide pastes for root canal filling (in Japanese, English abstract available). J Matsumoto Dent Univ Soc 2003; 29: 228–233.