2000 Volume 20 Issue 3 Pages 294-309
To study the provision of a suitable microenvironment for reparative dentine formation, wound healing in rat molar pulps was examined by light and electron microscopy following pulp amputation and direct capping with calcium hydroxide paste, folmcresol, or high molecular-weight hyaluronic acid. The effects of these pulp capping agents were compared. In hyaluronic acid-treated pulps, at 2 days after amputation, wound surfaces were covered with blood and fibrin clots and inflammatory cells such as neutrophils and macrophages. At 1 week after amputation, odontoblast-like cells produced globular calcified nodules along the existing dentine walls. At 2 weeks, a layer of reparative dentine had been formed by odontoblast-like cells over the dentine walls. Between 30 and 60 days, the formation of reparative dentine had extended throughout the pulp chamber. The healing observed after direct capping with hyaluronic acid was, except for the formation of dentine bridges, similar to those seen after calcium hydroxide or formcresol capping. These results suggest that high molecular-weight hyaluronic acid can provide an environment suitable for reparative dentine formation through mesenchymal cell differentiation during healing of the amputated dental pulp.
