In 2003 the project Changes in oral health and preventive behaviour was carried out for the sixth time in succession in the Netherlands. Children and adolescents were asked to fill out a questionnaire and to participate in an oral health examination. Compared to the 1996/1997 results 9-year-olds had a lower incidence of FS and DMFS, 14-year-olds had a higher incidence of DS, and 20-year-olds had a larger number of DS and a smaller number of FS, DMFS and DMFT in 2003. The care index in 2003 was between 48% and 68%. Compared to the 1996/1997 results more 21-year olds visited the dentist annually instead of twice a year. Considering possible consequences of the change in the Dutch health insurance system as of January 2006, such tendencies need careful monitoring.

This studys objective is to assess long term results of vertical distraction osteogenesis for the extremely resorbed edentulous mandible by clinically measuring and taking x-rays from the beginning of the treatment of 16 subsequent patients to its final moment in the follow up period (ranging from 2-62 months). Bone height, nerve sensitivity, complications and loss of implant were registered. Average bone resorption after 3 years was 11.2%. Out of 16 patients 5 experienced sensory nerve disturbance; 3 suffered complications. The implant success rate was 89,2%. Distraction osteogenesis appears to be a reliable technique, with which stable bone tissue is developed. Risk of sensory nerve disturbance and complications however, must be taken into consideration.

The failure load and failure mode of severely damaged endodontically treated maxillary premolars were examined within a laboratory study. The premolars were divided into 4 groups. The first of which was restored with prefab metal posts, the second with prefab fibre posts and the third with custom-made fibre posts; all 3 receiving direct resin crowns. In a 4th (control) group no post-space preparation was performed and no posts were placed; a direct resin composite complete crown was made. After thermocycling, all specimens were statically loaded in a universal test machine until failure, under an angle of 30. There was no significant difference between the mean failure loads. Failure was merely due to unfavourable, non-repairable fractures (ending below the simulation of bone level). This study suggests that posts are not necessarily required to increase the failure load of direct resin composite crowns, however, clinical studies are necessary to confirm these findings.

Periodontitis in humans can be divided into two clinical forms: aggressive and chronic periodontitis. Recent studies on the microbial composition of subgingival plaque reveal no major differences but for a slightly higher prevalence of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in the aggressive form. Treatment of both forms involves mechanical supra- and subgingival debridement and periodontal surgery on indication. Recently, it has been shown that adjunctive systemic antimicrobial therapy with metronidazole and amoxicilline significantly improves clinical treatment outcome in patients with generalized aggressive periodontitis. Microbial diagnosis appears to be a useful procedure in determining the most efficient use of antibiotics in treating patients with periodontitis.

A lot of attention has been paid to the questions of how and why teeth erupt. In the past many theories were developed, all of which showed mechanistic characteristics and suggested that a certain structure exerts force on the tooth germ to initiate its eruption. The dominant theory considered the collagenous fibres or the fibroblasts within the periodontal ligament to be the primary moving force in the eruption process. However, most research was done on continuously erupting incisors of rodents or lagomorphs, an experimental model with serious drawbacks. Because dogs, like humans, have teeth with limited eruption, 25 years ago research was carried out on tooth eruption in beagles. One of the most important conclusions of this study was that the periodontal ligament is not the primary moving force in tooth eruption, as its development only begins at the end of the eruption process. In subsequent years several others have focused their research on tooth eruption in beagles. The current state of knowledge in this field can be summarized as follows: the reduced enamel epithelium and the dental follicle control bone deposition and resorption around an erupting tooth germ, enabling its occlusal movement; the periodontal ligament develops only after its emergence in the oral cavity, and is thus not important in the eruption process; the tooth itself does not play a role in the regulation of its eruption.

An asymptomatic radiolucency between a vital 44 and 45 was detected in a 64-year-old woman. Treatment consisted of enucleation. Histopathologically, the features of a lateral periodontal cyst were observed. The lateral periodontal cyst is a rather rare developmental odontogenic cyst that has a tendency to recur after incomplete removal.

Detection of focal infections aims at the identification and subsequent treatment of sources of odontogenic inflammation in order to prevent health threats in patients who are often medically compromised. Examination for dental foci often precedes medical treatment of patients with increased risks of endocarditis, patients with a joint prosthesis, patients scheduled for chemotherapy or head and neck radiotherapy or candidates for organ transplantations. Although examination for possible sources of dental inflammation is performed on a routine basis in many hospitals, the scientific basis for this policy apparently is very limited, and there is an evident need for welldesigned randomized clinical trials in this field.