Before relining a complete denture, what essential step must be taken first?

The essential step that must be taken before relining a complete denture is to take new impressions. This is crucial because relining involves adapting the denture base to the current contours of the patient’s oral tissues, which may have changed due to factors such as bone resorption or soft tissue healing. Taking new impressions ensures that the new relining material accurately captures these changes, leading to a better fit and improved function of the denture.

Establishing posterior occlusion is important, but it typically occurs after new impressions have been taken and the denture is relined to ensure functional compatibility. Polishing the denture should occur after adjustments and modifications are made, not before relining since the surface may need to be altered. Adjusting occlusal height is also a step that is more relevant after the denture has been relined and is designed to accommodate the updated fit and function, rather than being a prerequisite for relining.