Denture relines involve adding plastic to the fitting surface of the denture to provide an improved fit. The process can normally be completed in a working day. An impression of the denture will be taken first thing in a morning by the Clinical Dental Technician. The denture will then be fitted later the same day. Relines are required after time and gum tissue changes, they will then restore the retentive qualities of the denture. These changes to gum tissue are quite normal and are mainly caused by bone loss and aging.