 Dentists use sedation to help patients accept difficult procedures and to relieve anxiety. During sedation, the well-being of the patient is monitored by the dental team. When carried out according to recognised guidelines,intravenous dental sedation is considered to be very safe. For some patients, dental sedation is a useful alternative to general anaesthetic. It is cheaper and has the potential to be more accessible. Oximetrymeasurement of oxygen status is the current gold standard in dental sedation. The main risk to the patient during sedation is a slowing of breathing due to the effects of the sedative drug. Studies from other settings where sedation is practiced suggest that an additional monitor with capnography facilitates early detection of depressed breathing. However, the results of studies from other medical settings cannot be generalised to dental sedation, because of different techniques used and the types of patients. The depth of sedation may also be vary. For dental sedation, patients remain responsive at all times and breathe for themselves. Capnography gives breath by breath information using a simple device placed close to the nose and mouth. It has been recommended by several governing medical bodies that each area of medicine, should develop its own guidelines for sedation. Therefore, there is a need to research the application of capnography for dental sedation. The proposed study will take place at a university hospital site. Patients will be randomly divided into two groups. Both groups will receive sedation in the normal way. The study group will have capnography monitoring added. The study will look for differences in breathing between the two groups. Additional information regarding other aspects of monitoring will also be obtained. The results from the proposed study may help to improve patient safety and change current practice during sedation for dentistry. 