Background: The two most common models of workforce planning are the "stock and flow" and the demographic approach. The former balances future losses from a system against recruitment and retention, whilst the latter simply "grosses up" current provision based on changes to population demographics. However, such approaches ignore the impact of improving health and can confuse demand with population need. On the supply side, they also assume that there will be no changes to working practice in respect of service levels and service delivery, or any improvements in medical technology. This paper aims to examine the complex interactions between these factors in order to take a more considered approach to workforce planning in dentistry. (Contains 1 table and 2 figures.)