'The last post?': assessment of the failing post-retained crown.

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.

DIAGNOdent laser fluorescence assessment of endodontic infection.

INTRODUCTION: Real-time assessment of the microbial status of the root canal system would be useful in clinical endodontic practice for determining endpoints of biomechanical treatment. This laboratory study used an existing laser fluorescence device, the DIAGNOdent (KaVo, Biberach, Germany), in a proof-of-concept study. METHODS: Visible laser red light (wavelength 655 nm) was used to elicit fluorescence emissions in the near-infrared range from infected and uninfected root canals. A prototype sapphire tip designed for periodontal assessment was used to analyze the pulp chamber and coronal third of the root canal system in extracted teeth. The fluorescence properties of bacterial cultures, monospecies biofilms in root canals, pulpal soft tissues, and sound dentin were also evaluated, together with 50 extracted teeth with known endodontic pathology. RESULTS: Sound dentin and healthy pulpal soft tissue gave an average fluorescence reading of 5 (on a scale of 100), whereas biofilms of Enterococcus faecalis and Streptococcus mutans established in root canals showed a progressive increase in fluorescence over time. Fluorescence readings reduced to the "healthy" threshold reading of 5 when root canals were endodontically treated, and the experimentally created bacterial biofilms were removed completely. High fluorescence readings were recorded in the root canals and pulp chambers of extracted teeth with radiographic evidence of periapical pathology and scanning electron microscopy evidence of bacterial infection. CONCLUSIONS: The use of the DIAGNOdent fluorescence approach for the assessment of the status of the pulp chamber and root canal system holds promise for clinical application; once more, flexible tips can be developed for gaining greater penetration into middle and apical thirds of the root canal.

Cost-effectiveness decision analysis of obtaining periapical radiographs of traumatized maxillary incisors.

A long-term decision analysis approach has been applied to the problem of whether or not periapical radiographs should be taken routinely of patients presenting with simple fractures of otherwise asymptomatic maxillary incisors. Information from the literature concerning the accuracy of cold, hot and electrical tests for pulp vitality, combined with data on the accuracy of radiographic diagnosis of periapical pathology, and therefore vitality, has been used in the analysis of the diagnostic problem structured in the form of a decision tree. By adding information concerning the direct costs of examining and treating patients over a 10-year period to the analysis and varying the likely prevalence of periapical lesions in a three-way sensitivity analysis, the following results were arrived at: (1) if the disease prevalence in teenage patients is < 5%, it is economically justifiable to make a visual inspection only and then to proceed with simple restorative treatment; (2) if there is evidence from the clinical examination or patient history that the prevalence of pulp necrosis is between 5% and 50% then, in our case, radiographs were the most appropriate single diagnostic test.

On decision making in endodontics. A study of diagnosis and management of periapical lesions in endodontically treated teeth.

In radiographic evaluation of the results of endodontic therapy the development or persistence of periapical radiolucencies often serve as criterion for therapeutic failure. However, using three endodontists and three oral radiologists as observers the present study found consensus only in 27% of cases classified as having periapical radiolucencies. By applying signal-detection theory to periapical radiographic diagnosis, the variations among observers were explained by their adoption of different criteria of periapical disease resulting in different positions on a receiver-operating-characteristic (ROC) curve. The potential of reducing the interexaminer variation through two different calibration programs was investigated. Even though both methods resulted in increased examiner agreement the benefits seemed limited. It was argued that this is due to the complex structure of the decision making process. Among a group of well-experienced general practitioners substantial variations in attitudes to treatment of periapical lesions in endodontically treated teeth was demonstrated. From decision theory and endodontic teaching paradigms a hypothesis was evolved explaining the variations in treatment with variations in subjective probabilities of disease and expected complications. However, this hypothesis could not be confirmed in groups of endodontists and general practitioners. Instead the decision makers seemed to rely on a limited number of heuristic principles. From a normative point of view clinical management of periapical lesions in endodontically treated teeth was approached by using formal decision analysis. Temporal and logical display of decision alternatives, values of probabilities and utilities of the different outcomes are the features of such an analysis. In the concluding part of the study this method was used to calculate optimal decision strategy for an endodontic recall program. It was demonstrated that patients should be examined one year after endodontic treatment. Patients with signs of periapical disease are reexamined after a further three years. At this moment a mild suspicion of periapical pathosis will lead to retreatment of a tooth.