No abstract

Failure of a post-retained restoration can provide a challenge to the general dental practitioner (GDP) in terms of diagnosis, treatment planning and communication with the patient. The cause of failure must be identified, and a thorough assessment of the restoration, remaining tooth and its functional and aesthetic demands carried out in order to plan treatment to provide the most reliable result. Clinical Relevance: This article discusses the assessment of failing post-retained crowns, with discussion of reasons for failure, thereby assisting the GDP in decision-making and treatment planning for such teeth.

To effectively carry out root canal therapy, the clinician must accurately determine the apical limit of the root canal system as well as the position of the canal terminus. Its position can be estimated using a variety of techniques, including radiographs, tactile feedback from endodontic instruments and electronic apex locators. This article describes the micro-anatomy of the apical terminus, different methods of measuring root canal system length and how a tooth can function as an electrical capacitor. This capacitor model represents a starting point upon which all apex locators are based. An understanding of this model can help the practitioner to optimise the use of apex locators, understand their limitations and avoid errors that can occur.