DA Dixon

Optimal intake of vitamin D and calcium slows bone resorption and ensures adequate calcium for bone mineralisation. Optimal levels of vitamin D should have an immunosuppressive effect on periodontal disease. Older adults, particularly those with dark skin colour and/or those who live in northern latitudes, should consider oral vitamin D supplementation.

To provide an overview of radiographic film holders, from their inception in the early 1900s to present day. A Medline literature search was conducted for dental studies that used keywords that pertain to radiographic film holders. Hand searches of the bibliographies were also conducted. Sixty articles (dating from 1896 to 1998) that describe new or improved film holders are reviewed here. From the earliest days of dental radiography, dentists attempted to standardize radiographic images and techniques. The focus of researchers in the 1950s to the 1970s was to develop a film holder that would hold the film and allow easy and predictable alignment of the X-ray tube. As research projects became more dependent on dental radiographic measurements, the focus shifted to producing reproducible radiographic images, from which highly repeatable measurements could be made. Existing devices have strengths and weaknesses. Readily available devices are adequate for routine clinical use; however, user-friendly and patient-friendly film-holding devices that result in highly reliable and accurate measurements have yet to be introduced.