Retention is not an unambiguous variable. The degree of retention is dependent on biologic and physiologic properties of a complete denture and the denture-bearing and surrounding tissues. Quantifying retention forces of a complete denture can be carried out with three types of methods: subjective methods, methods with clinical more or less objective criteria, and nearly entire objective methods using measurement equipment. The subjective and most of the methods with clinical criteria are not or little reliable. However, for epidemiological research the methods with clinical criteria are very pragmatic. Of all objective methods using measurement equipment, the gnathodynamometer is the only apparatus with proven reliability.

This article briefly outlines the principles of economic evaluation in dentistry. It discusses the different types of analyses, such as cost-effectiveness analysis, cost-benefit analysis and cost-utility analysis. Furthermore, it makes clear when these analyses are most appropriate for use. Having a basic understanding of the most common analyses can be helpful to make choices between different interventions. Increasing demand for dental interventions and limited budgets necessitate the allocation of scarce resources efficiently. By identifying, measuring, valuing and comparing costs and outcome of interventions, economic evaluation can also help patients and carers in choosing between interventions. The article gives some examples in restorative dentistry to explain the relevance of economic evaluation.

Porphyria is a disease of specific enzymes in the biosynthesis of heme, caused by either genetic defects or environmental factors. This review of the literature presents the different types of porphyria and describes their possible causes, clinical signs, diagnosis and therapy. In addition, oral findings observed in patients with porphyria and the potential implications of the disease for dental treatment are discussed.

Processes playing a role in normal odontogenesis may also occur in development of odontogenic tumours. Studying odontogenesis may shed new light on the pathogenesis of odontogenic tumours and studying odontogenic tumours may do the same for understanding normal odontogenesis. An overview is given on the developments in this field since the last 25 years. Analysis of protein and gene expression have deepened the understanding of mechanisms playing a role in odontogenesis but thus far has not contributed very much to the knowledge on the pathogenesis of odontogenic tumours.

According to some people, the renewed Dutch civil disciplinary law is not fulfilling the expectations. Some procedures seem to be redundant for accused dentists. Besides the civil disciplinary law, also the professional disciplinary law of the Dutch Dental Association is questionable. The Association is planning to change the current professional disciplinary law. However, the proposed amendments may have the consequence that a Dutch dentist more frequently will be faced with a civil disciplinary law procedure or a normal civil law procedure.

A 26-year-old woman was referred by a dentist to an oral and maxillofacial surgeon after an unsuccesful attempt to remove a mandibular third molar. A panoramic radiograph showed the remaining root of the third molar and the patient suffered from insensitivity of the lower lip. The root of the third molar was removed surgically. The sensitivity of the lip recovered completely within three months. Injury of the inferior alveolar nerve and the lingual nerve is a serious complication after mandibular third molar removal. The inferior alveolar nerve is at risk for injury if the third molar root is intimately connected with the mandibular canal. Refraining from preoperative clinical and radiographic diagnostics is malpraxis. Surgical skill is a prerequisite to reduce the risk of nerve injury.

Providers of continuing postgraduate education in dentistry are more and more using quality trustmarks. Trustmarks are getting well-known among general practitioners. On the website of the Dutch Q-trustmark one can read the requirements to acquire this quality trustmark.