Impact of the extension of the anterior-posterior spread on quality of life and satisfaction of patients treated with implant-retained mandibular overdentures-a randomized clinical trial

Objectives: To compare the degree of satisfaction (SD) and the impact on oral health-related quality of life (OHRQoL) of edentulous patients treated with conventional complete dentures (CCDs) and mandibular overdentures (IODs) with a short anteroposterior spread (S-APS) or a large antero-posterior spread (L-APS). Materials and methods: Edentulous patients were treated with CCDs and subsequently randomly allocated to receive a bar clip mandibular overdenture retained by 2 interforaminal implants (Control) or 4 (Test: 2 additional implants distal to the mental foramen). The Oral Health Impact Profile Edent questionnaire (OHIP-20E) and the Visual Analogue Scale (VAS) were applied at a mean follow-up of 38.5 months to assess the impact on OHRQoL and DS, respectively. Comparisons between the type of prosthesis and the extension of the AP spread were made with Student's t test for paired samples and for independent samples, respectively, at a significance level of 5%. Results: The IODs had significantly lower OHRQoL values in the dimensions "functional limitation" (p=0.03), "physical pain" (p=0.02), "psychological discomfort" (p<0.01), "disability physical" (p<0.01) and "general score" (p<0.01) (n=20 patients). The IODs presented DS values significantly for "aesthetics" (p=0.04), "stability" (p=0.03), "masticatory capacity" (p<0.01), "function" (p<0.01) and "oral condition" (p=0.03). The S-APS group (control) resulted in significantly lower values in the dimensions "physical pain" (p<0.01) and "general score" (p<0.01) and no domain with statistical difference in the VAS scale. Conclusions: IODs significantly improved OHRQoL and DS. The increase in AP spread did not result in benefits for the patient's OHRQOL and DS in this clinical study. (Study Protocol Number: 1.452.492) Clinical Significance: Implantology has experienced in the last 20 years a permanent evolution that aim at increasing predictability and improving long-term clinical performance. Placement of short implants distally to the mental foramen, for instance, and the resulting increase of the anterior-posterior spread, is a promising approach and is worthy of investigation.