Background This is the third paper in a series of four examining a tool which could be used to determine sedation need among patients.Aim The aim of this paper was to assess the reasons why people do not attend the dentist regularly, in order to understand the potential need for sedation services among both attending and non-attending patients.Methods and results A large telephone survey conducted across 12 primary care trusts (PCTs) found that 17% of participants did not attend the dentist regularly. One of the top reasons given for non-attendance that could be considered a barrier was fear/anxiety. The figure reached in paper 2 (A 2011; 211: E11) stated that approximately 5% of attending patients will, at some time, need sedation services. However, the data from this survey have suggested that anxiety accounts for 16% of people who do not attend the dentist regularly.Conclusion It could be assumed that if non-attending patients were included, with high levels of anxiety, the sedation need would rise to 6.9% throughout the entire population. © 2011 Macmillan Publishers Limited. All rights reserved.