Dental treatment profile of New Zealand Defence Force personnel.

OBJECTIVE: To evaluate the dental treatment provided over one year to serving personnel and new entrants in the New Zealand Defence Force (NZDF). METHOD: Dental treatment data from 4,380 personnel in the 12 months following their last annual dental examination were retrieved and evaluated from electronic data archives. These included all treatment provided for 2000 randomly-selected regular serving personnel and for all 2380 new entrants entering the Service in the years 2005 and 2006. RESULTS: Treatment data were recorded for 1770 (88.5%) of the 2000 serving personnel in the year following their last dental examination. Excluding examinations and radiographs, treatments averaged 2.3 per person. Amalgam and composite restorations contributed 40%, preventive and oral hygiene services 44%, and tooth extractions 6% of treatments; the "other" category amounted to 10% of treatments. For the 2380 new entrants, treatment data were recorded for 1959 (82.3%) during their first year of service. Treatments averaged 3.6 per person; amalgam and composite restorations contributed 58%, preventive and oral hygiene services 25%, and extractions 10%. The remaining 10% of treatment items recorded comprised a diverse range of procedures. CONCLUSIONS: The level of treatment provided was low for both serving personnel and new entrants. Ninety percent of teeth were present and functional. Amalgam and composite restorations, preventive care and oral hygiene procedures made up the majority of treatment provided.

Dental status of New Zealand Defence Force personnel.

BACKGROUND: No epidemiological data are available on the dental health of New Zealand Defence Force personnel. AIM: To describe the oral health status of serving personnel and new entrants in the New Zealand Defence Force (NZDF). METHOD: The dental records of 4,380 personnel were transcribed from an electronic archive of individual clinical data. Twenty defined codes were used to record the dental status at their last annual examination and first entrant examination. This study evaluated the dental status of 2000 randomly-selected serving personnel and of all 2,380 new recruits over the period 2004 to 2006. RESULTS: Among the serving personnel, 88% had a full complement of natural teeth. Fifty-two percent of erupted teeth were sound. Fifty-six percent of the remaining teeth had been restored with amalgam or composite material; 25% were missing (or unerupted), and 19% were distributed between the remaining 10 status codes. Some 55 dentures were recorded (0.2% of total codes). Among the new entrants, 90% had a full complement of natural teeth; 72% of those teeth were recorded as sound. Among the other 28%, 46% had been restored with amalgam or composite material, 36% were missing or unerupted, and 19% were distributed between the remaining 10 status codes. Thirteen dentures were recorded (0.2% of total codes). CONCLUSIONS: This first epidemiological evaluation of the dental status of NZDF personnel revealed an encouraging standard of dental health among serving personnel and new entrants. Overall, we believe that the dental needs or demands of the majority of NZDF personnel are unlikely to interfere with their operational tasks.

Health effects of dental amalgam exposure: a retrospective cohort study.

BACKGROUND: Whether dental amalgam fillings (containing mercury) are hazardous is a long-standing issue, with few epidemiological investigations. Allegations have particularly involved nervous system disorders, such as multiple sclerosis, Alzheimer's disease, and chronic fatigue syndrome. This retrospective cohort study, the largest of its kind, contained people in the New Zealand Defence Force (NZDF) between 1977 and 1997. The NZDF has its own dental service, providing all personnel with regular and consistent treatment. Comprehensive treatment records are maintained and archived. METHODS: Yearly dental treatment histories, including amalgam filling placements, were compiled from individual records. To minimize amalgam exposure misclassification the cohort was restricted to people who, at NZDF entry, were aged <26 years and had all their posterior teeth. The cohort was linked with morbidity records. Data were analysed with a proportional hazards model, using a time-varying exposure unit of 100 amalgam surface-years. RESULTS: The final cohort contained 20 000 people, 84% males. Associations with medical diagnostic categories, particularly disorders of the nervous system and kidney, were examined. Of conditions allegedly associated with amalgam, multiple sclerosis had an adjusted hazard ratio (HR) of 1.24 (95% CI: 0.99, 1.53, P = 0.06), but there was no association with chronic fatigue syndrome (HR = 0.98, 95% CI: 0.94, 1.03), or kidney diseases. There were insufficient cases for investigation of Alzheimer's or Parkinson's diseases. CONCLUSIONS: Results were generally reassuring, and provide only limited evidence of an association between amalgam and disease. Further follow-up of the cohort will permit investigation of diseases more common in the elderly.

Artificial mouth model systems and their contribution to caries research: a review.

The complexity of the oral environment, and ethical problems associated with studies of oral diseases in humans inevitably directed the attention to development of laboratory models, that simulate the human oral microcosm. These developments and in particular the in vitro 'artificial mouth' systems have progressed from simple and basic apparatus devised by Magitot and Miller at the end of 19th century to the currently available, highly sophisticated, computer-controlled, multi-station artificial mouth systems. These advances have metamorphosed from the early studies devised primarily to investigate factors affecting the carious process to the present designs that evaluate growth, pathogenicity, metabolism and mineralization of dental plaque under highly controlled conditions. The modern 'artificial mouth systems' can evaluate microbial interactions in simulated dental plaque and similar biofilms and monitor their physical, chemical, biological and molecular features to a very high degree of accuracy. We review and trace here the historical aspects and developments leading to the currently available artificial mouth systems and discuss their contribution to the study of oral flora, especially related to many variants of dental caries.