Hyde 2010.

Methods	Study design: cross‐over RCT (three arms) Conducted in Leeds Dental Institute, University of Leeds, United Kingdom Number of centres: 1 Recruitment period: November 2006 to November 2008 Funding source: funded by a grant from Dunhill Medical Trust Study duration: November 2006 to June 2009
Participants	Inclusion criteria: people who were able to attend, with edentulous lower arch; had the mental foramen apparent clinically or radiographically on the denture‐bearing area of the lower ridge Exclusion criteria: people who were allergic to acrylic or silicone rubber 102 people assessed for eligibility. 69 randomised and allocated to block randomisation. 66 completed study
Interventions	Intervention 1: control ‐ standard technique (relative mucostatic) The dentures were constructed on a cast made using relatively mucostatic impression. The impression procedure used a spaced acrylic custom tray taken with medium‐bodied silicone material, followed by a light‐bodied silicone final impression. Intervention 2: traditional technique (redistribution of pressure) This method used 0.6 mm metal foils as relief, placed over the area of the mental foramina, and processed the finished denture on the spaced cast. Intervention 3: selective pressure technique To relieve pressure over the mental foramen, silicone from impression was removed by cutting from the area above the mental foramen. The custom impression tray was perforated in this area and final impression was made using light‐bodied silicone. Block randomisation was used to encode the dentures. The order of randomisation was maintained by a designated research nurse who delivered the encoded denture, without the prior knowledge of the clinician, for the participant to wear for one week. The participant wore each denture for one week and collected the second and third denture to assess each denture individually. The cross‐over did not have a washout period. Participants were given all three dentures together to wear for 1 to 2 weeks each, and asked to report the preferred denture. The preferred denture was worn for three months by the participant and all outcomes were assessed.
Outcomes	Primary outcome: impact of new dentures on quality of life by using OHIP‐14 self‐assessment questionnaire at baseline and after three months Secondary outcome: participant preference for dentures after four to five weeks of usage
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The order in which the dentures were assessed by the patient was determined by a block randomisation procedure."
Allocation concealment (selection bias)	Low risk	Quote: "The order the encoded dentures were to be worn was revealed on the day of insertion of the first denture by a designated research nurse, without the prior knowledge of the clinician."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The clinician, dental nurse and participants were blinded to the method of fabrication of the dentures.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	All outcome assessments were performed by participants; they were recorded by the research nurse and the dentist remained blinded to the choice.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: only three participants were lost to follow‐up, and this was accounted for in the final analysis.
Selective reporting (reporting bias)	Low risk	Comment: all outcomes were reported as planned.
Other bias	Low risk	Comment: no other bias found