Clinical determination of angle convergence in a tooth preparation for a complete crown.

The relationship of the convergence angle (CA) to the height of the axial walls is the most important factor for providing retention and resistance in tooth preparation for a complete crown. Several studies have shown that the ideal CA is difficult to achieve in clinical practice. The technique described in this article allows for the determination of the CA during the tooth preparation procedure, based on an instrument developed and created by the authors.

Identification of medically compromised dental patients in a Portuguese population.

PURPOSE: The age of the patients, the presence of one or more chronic disorders and the patients' drug regimens can influence dental treatment and oral health. This is a prospective, descriptive study to identify subjects with compromised health who received dental treatment between November 2010 and June 2011 at private dental practices run by graduates of the Portuguese Catholic University. MATERIALS AND METHODS: Application software in Microsoft Excel was developed containing the questionnaire, based on the EMRRH (European medical risk related history), which allowed the collection of data from 1603 adult patients. Microsoft Excel, G*Power and SPSS V.18 were used for statistical treatment. RESULTS: The five most frequent medical conditions found were: 1) hypertension, 21.0%; 2) arrhythmias, 11.2%; 3) Angina pectoris, 8.3%; 4) allergies, 77%; 5) thyroid disease, 6.2%. The medications taken related to these were: a) antihypertensives, 11.0%; b) antidepressants, anxiolytics and hypnotics, 10.6%; c) acetylsalicylic acid, 4.2%; d) antiarrhythmic and sympathomimetic drugs, 4.1%; e) haemostatic treatment, 3.6%. 42.7% of the patients had no medical risks, 32.9% were classified as ASA II, 11.7% as ASA III and 12.7% as ASA IV. CONCLUSION: This study emphasises the importance of often-neglected anamnesis in oral care. The high prevalence of patients with medical conditions should be continuously studied to verify the changes over time and should be expanded to other regions and countries.

Classification of extensively damaged teeth to evaluate prognosis.

The restoration of teeth with extensive structural damage is an important clinical procedure in dental practice. However, despite the availability of a variety of materials, techniques and studies in the scientific literature, the criteria for selection of such teeth for restoration need clarification. The approach to severely compromised teeth should be based on consistent scientific evidence to reduce dental error and improve the prognosis. If restoration is indicated, it must conserve and protect the remaining tooth structure. In this article, we develop and suggest clinical criteria and guidelines that clinicians may use to identify and classify extensively damaged teeth to help in the diagnosis, treatment plan and prognosis.