[Prosthetic abutment preparation related to tooth shape and pulp extension].

Using a radiographic measuring technique, the authors determined the pulp-hard tissue ratio in 759 extracted, cariesfree, maxillary and mandibular teeth of exactly indicated ages. On the basis of the results obtained, recommendations are given for the depth of preparation of the various surfaces of the teeth as related to their ages. The suitability of various types of preparation for prosthetic abutments is discussed. For the preparation of the vestibular surface, the authors describe a modification of the grooving technique as yet recommended.