Is a two-step impression mandatory for complete denture fabrication on the severely resorbed mandible? A randomized trial on patient perception and denture quality

Objectives: To evaluate the effectiveness of CCDs produced by two impression procedures for the mandibular ridge, in patients with severe mandibular atrophy.

Methods: Fifty-two completely edentulous patients with severely resorbed mandibles were randomly allocated into two groups according to the impression procedure of the mandibular ridge: SI - single impression (stock tray and irreversible hydrocolloid); TI - two-step impression (custom tray, border molding with compound, and polyether). Assessments of oral health related quality of life (OHRQoL, primary outcome) and denture satisfaction were performed by using validated questionnaires. Denture quality was evaluated by means of functional tests.

Results: Regardless of the technique, participants reported better OHRQoL (P < 0.001) in both follow-up periods (3 and 6 months after denture delivery), and groups resulted in similar OHIP-EDENT scores in its different domains (P > 0.05). Between-group differences were insignificant for general satisfaction (3 months, P = 0.699, 6 months, P = 0.392), as well as for aspects such as esthetics, comfort, mastication, speech, and prosthesis retention (P > 0.05). Overall clinical quality of the CCDs (P = 0.383) was similar between-group, as well as in specific aspects - interocclusal distance, occlusion, articulation, retention of the maxillary denture, and stability of both maxillary and mandibular dentures (P > 0.05).

Conclusions: Mandibular CCDs based on a single impression technique showed quality levels comparable to those generated by a two-step impression, both from the patient and clinician perspective.

Clinical significance: A simplified impression technique which eliminates the secondary impression can provide CCDs of good clinical quality, which influences the OHRQoL, and satisfaction in the same extent they would by a two-step procedure, even for patients with severely reabsorbed mandibular ridges. (ClinicalTrials.gov: NCT02339194).