Richard E. Stallard

Periodontic-endodontic relationships

Abstract An obvious relationship exists between poor oral hygiene, the accumulation of dental plaque, and the development of both gingivitis and dental caries. The association between pulpal pathosis and periodontal disease, however, is not as well established. In fact, all too often the dental pulp and periodontal supporting structures are considered as separate independent entities. Clinical experience with root sensitivity, unexpected pulpal death following periodontal therapy, and failure of some periodontal lesions to respond to therapy without endodontic treatment points to an interrelationship. Although reports appear in the literature stating that there is no relationship between the severity of periodontal disease and changes in the dental pulp, other investigators report that a definite relationship exists between the presence of periodontal lesions and the status of the pulpal tissues. Both hypotheses cannot be true; therefore, an attempt is made in this article to summarize the existing evidence and report current investigative findings in this area as viewed by the teacher, researcher, and practitioner.

Tissue reaction to jet injection

Abstract An animal study of injections delivered by the jet technique reveals that injected solutions follow lines of least resistance in the fascial planes; both jet and needle injection techniques produce similar inflammatory responses in the underlying tissues, the severity of which depends on the amount of trauma or damage to those tissues; inflammatory reaction is more localized with needle injections than that observed with jet injections; adventitia of blood vessels, perineurium, and periosteum apparently form a barrier that the jet stream cannot easily penetrate after it has lost its velocity following penetration of the tissues; and the amount of loose areolar connective tissue present subcutaneously at the injection site determines the volume which may be accommodated by the tissues.