Tentative conclusions : Applications of concentrated solutions of vitamin D, as dressings over nearly exposed pulps in children, appear to stimulate barrier response. This does not occur if there was an antecedent pulpitis.
Method: Large carious cavities were excavated in permanent teeth of children. When the pulps were nearly exposed, dressings containing vitamin D were inserted, sealed with cement and left for about a month. On removal of the dressings, many cavity floors appeared to have hardened ; comparison of radiographs suggested that the dentin between cavity and pulp had become thicker. In thirty- three cases, using solution of vitamin D (3,000 internat. units per grm.) and vitamin A (Carr-Price 500) in oil, twenty-six appeared to show barrier stimulation. Using vitamin D in oil only (3,000 internat. units per grm.), nine out of ten cases showed barrier stimulation. Controls, using boiled olive oil, showed no response.
Reference: Some observations on the conservative treatment of the dental pulp, M.D.S. thesis, University of Durham, 1935.