Replacing missing lower back teeth with an implant-supported removable partial denture.

Two treatment options will be compared (the trial will be designed as a within-subject cross-over trial, hence each subject will experience both interventions): a) use of a conventional removable partial denture. This will involve standard clinical practice in designing and constructing a removable partial denture. In general, it will involve approximately 4 clinical appointments, each lasting between 30-60 minutes each. The appointments will generally be about 1 week apart, depending on how quickly the dental laboratory can prepare and return the required denture work. The denture will be tooth retained. After a 3 month adaptation period, a range of simple clinical tests and questionnaires will be used to assess the denture performance (approximately 2 hour appointment). b) use of a removable partial denture retained and supported by dental implants. This will involve the surgical placement of two short and narrow implants per patient, conducted under local anaesthetic. The surgical appointment will take approximately 2 hours. Following healing (minimum of 6 weeks), the removable partial denture will be modified to incorporate the resilient retainer system (approximately 2 hour appointment), hence the denture will be both tooth and implant retained (after a 3 month adaptation period, a range of simple clinical tests and questionnaires will be used to assess the denture performance (approximately 2 hour appointment). . There will be a minimal-to-no wash-out period between the two treatment options. The dentures will be modified such that the patient will experience the alternate treatment option. The aim will be for one operator to conduct all treatments, hence minimising the potential for operator inconsistencies.