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The tangential projection represents an extraoral projection which with success can be performed with the dental X-ray set. The film is placed lateral to the angle of the mouth in a vertical position level with either the maxilla or the mandible. If a view of the midline is wanted the film is placed parallel with the sagittal plane; if e.g. the canine region is of interest the film is angulated. The central X-ray is directed horizontally and perpendicularly to the film passing (as a tangent) the anterior surface of either the maxilla or mandible. The beam area used for periapical projections is ideal also for this projection. The tangential projection is indicated as a supplemental projection for three-dimensional localization of e.g. supernumerary teeth in the maxillary anterior region and for the buccolingual position of an impacted canine. It is also very useful in combination with frontal projections in the planning of insertion of dental implants. According to the Danish legislation it is not allowed to use the dental X-ray set for extraoral projections unless intensifying screens are used. However, the Danish Institute of Radiation Hygiene has accepted tangential projections using dental X-ray films and omitting intensifying screens in edentulous patients due to their better resolution, which is of particular importance in the planning of implant insertion.

The retention of composite inlays depends on acid-etching of marginal enamel of the preparation. In many cases, only little marginal enamel is available, making loss of retention a liability. The present study evaluated the retention of three brands of composite inlays under various conditions. Inlays were fabricated and cemented in standardized enamel/dentin cavities prepared in extracted human teeth. The force necessary to extract a cemented inlay was used to express the retention of the inlay. The effects of thermocycling and choice of dentin-bonding agent on inlay retention were also determined. Inlays made of Estilux posterior C VS were more retentive than inlays of either Brilliant Dentin or SR-Isosit. The latter two products were found to provide similar retentive strengths. The retention of Estilux posterior C VS and SR-isosit inlays declined when samples were thermocycled. Treatment with Gluma increased retention of inlays, resulting in retentive strengths of the same magnitude for all three inlay systems. The choice of dentin-bonding agent was found to affect composite inlay retention to a greater extent than the choice of either composite brand, mode of inlay curing, or effect of thermocycling.

The use of a protective leaded shield as an alternative to leaded aprons and leaded neck collars for reduction of body doses originating from scattered radiation in intraoral radiography is discussed. The shield is stiff and has a U-shaped form fitting the neck of the patients and is kept in position by the patient himself. During exposure the shield is pressed against the patient's neck and kept in close contact with the inferior border of the mandible in a horizontal position. Three products of shields are described, all having lead equivalents of 0.5 mm. The protection of the thyroid gland is of maximum efficiency. Measurements of absorbed doses have shown the shield to have a protective effect equal to leaded aprons in cranial body regions, while gonadal doses are a little higher. Upper extremities are always protected by a shield, while many patients keep their hands and arms upon and not under an apron. Shields are easy to handle for the staff, hygienic, and cheaper than an apron. They can hardly be damaged and leaks following handling will not occur as for aprons. Leaded shields have recently been accepted as alternative to leaded aprons by the Danish National Institute of Radiation Hygiene.

The color stability of three composite resins used in the inlay/onlay technique was determined by means of irradiation with UV-light and by water storage. Generally, water storage resulted in greater changes in color than did UV-light, but no correlation was found between the results of the two chromogenic procedures. The microfilled composite resin was the least color stable, but none of the resins had alarmingly low color stability.

This paper reviews a series of paleo-pathologic studies made to investigate associations between dietary factors and development of occlusion, periodontal diseases and caries. The findings indicate that the change from hard to soft food, which has taken place during the last few hundred years, influences occlusion, craniofacial structures and oral health in several ways. Comparative studies show that the frequency of malocclusion has increased substantially. In the same time, a number of alterations have taken place in the morphology of the craniofacial skeleton. The results support the hypothesis that masticatory stress is a regulative factor in craniofacial growth and occlusal development. With soft food and low masticatory activity, jaw growth is not adequate for optimal occlusal development. Approximal wear itself, caused by the attritive diet, seems to be only a minor adjustive factor. Because of the occlusal wear, the crown height decreased with age and the teeth continued to erupt. As a result, root surfaces were exposed. This process has been equated with bone loss but the lack of inflammatory changes on the bone surface indicates that the alveolar bone was not affected by periodontal diseases. This suggests that the alveolar height was maintained at a constant level throughout life and no growth nor resorption took normally place at the crest. Only the exposure of the furcations increased the occurrence of periodontitis. The caries frequency was decreased by mechanical cleaning effect of attritive food but increased by exposure of the root surfaces. Furthermore, the oral microflora may have been modified by factors related to the chemical and physical properties of the diet.

Cooperation between Scandinavian Victim Identification Commissions was tested thoroughly after the ship disaster at Easter 1990. The fire claimed 158 victims all killed by poisonous smoke from a fast spreading fire, which went on for 36 hours. Many of the bodies were found incinerated in burnt-out cabins. More than 100 specialists were at work for 17 days before all missing persons were identified. The whole operation was led by the Norwegian authorities in Oslo. They decided that a search for human remains should be attempted in the destroyed part of the ship by help of police technicians, forensic pathologists and forensic dentists. The placing of forensic and dental expertise at the site of the disaster made it possible to identify all victims of the fire. Eighteen forensic trained dentists supported the work: thirteen from Norway, four from Denmark and one from Iceland. Two of the Danish dentists were placed at police headquarters in Copenhagen preparing the antemortem data from the Danish passengers on the ship.

The accuracy (fit) of MOD inlays of three brands of composite resin was determined by measuring the axial discrepancy (marginal opening in the approximal area). The axial discrepancy varied between 17 and 121 microns. Directly manufactured inlays were more accurate (axial discrepancy: 17-26 microns) than indirectly manufactured inlays (axial discrepancy: 40-121 microns). Inlays of a microfilled resin, SR-Isosit, were less accurate than inlays of two hybrid materials, Brilliant Dentin and Estilux posterior C VS (axial discrepancy: 121 microns vs 44 and 41 microns respectively). There was a tendency for 24-hour-old inlays to be less accurate than 10-min-old inlays. The formation of marginal gaps due to contraction of the resin cement was assessed in a light microscope on cemented single-surfaced inlays. Gaps were not formed when enamel margins were etched or dentin margins treated with a dentin-bonding agent of high efficacy. Gaps (2.4-5.6 microns) were formed, however, at untreated dentin margins and at margins treated with dentin-bonding agents of low efficacy.