Ronald J. Heys

Histological Considerations of Direct Pulp Capping Agents

The results from this study showed a variety of pulpal responses to various calcium hydroxide materials when placed directly on the dental pulp. Two of the materials proved to be more successful at stimulating reparative dentin bridging and healing of the underlying pulp tissue. The remainder of the pulp capping agents were ineffective at healing the pulp and forming a reparative dentin bridge. When teeth were capped with these other agents, the pulp showed necrosis and chronic inflammation.

Healing of primate dental pulps capped with Teflon

The pulps of Rhesus monkey teeth were exposed and capped with three materials: Teflon, a commercial hard-set calcium hydroxide (Ca(OH)2) material, and Ca(OH)2 plus saline. Experimental test periods were 3, 10, and 21 days, and 5 and 8 weeks. After treatment, the teeth were removed and processed for routine histologic evaluation. Teeth treated with the two Ca(OH)2 materials showed resolution of the inflammatory response and hard tissue formation at the exposure site as early as 10 days postoperatively, with consistent healing at 21 days and longer. Teflon had a similar soft tissue healing pattern but at a slower rate. Hard tissue formation at the exposure site in the teeth treated with Teflon was infrequent at the early time periods and present in only 20% of the teeth treated for 5 and 8 weeks. By evaluating the soft and hard tissue responses of the Ca(OH)2-capped and Teflon-capped teeth it may be possible, in future studies, to identify events unique to odontoblast differentiation during pulpal healing.

The effect of various restorative materials on the microhardness of reparative dentin.

This study showed a statistically significant difference between the microhardness of reparative and primary dentin at both five- and eight-week intervals. Reparative dentin from occlusal trauma is harder than reparative dentin underlying a cavity preparation at the 99% level. No statistical difference was noted in the hardness of reparative dentin underlying different materials, but trends were observed.

Quality assessment of amalgam and inlay restorations on posterior teeth: a retrospective study.

This study was designed to assess and compare the quality of posterior proximo-occlusal amalgam and inlay restorations relative to type of restoration (material, surfaces involved, and cusp protection) and length of service of the restorations. A clinical evaluation system based on operationally defined and clinically important criteria was used. Clinically and statistically significant differences were found between overall ratings for amalgam and inlay restorations and between small (two-surface) amalgam and inlay restorations, as well as between larger (three-surface) amalgam and inlay restorations. In all cases, inlay restorations were of higher quality. A not acceptable rating for marginal integrity was the most frequent reason for not acceptable overall ratings. There was no difference in satisfactory/not acceptable ratings for inlay restorations with or without protected cusps (p = .95).