A retrospective study on patient satisfaction and Oral Health-Related Quality of Life with fixed 4- or 6-implant supported prostheses over 3-7 years.

Objectives: To compare patients' satisfaction and oral health-related quality of life (OHRQoL) in edentulous patients treated by All-on-4 and All-on-6 implant-supported fixed prostheses rehabilitation over 3-7 years.

Methods: All patients (n = 125) were divided into short-term (3-5 years, n = 71) and long-term (5-7 years, n = 54) follow-up groups. Patients' satisfaction was examined in a cross-sectional survey. OHRQoL and psychological impact were evaluated using the Oral Health Impact Profile (OHIP). Comparison of All-on-4 and All-on-6, including OHIP values, satisfaction scores, treatment duration and complications, were analyzed using the Chi-square test and the Mann-Whitney U test. Potential influence of patient-related factors on patient-reported outcome measures (PROMs) were analyzed via the Mann-Whitney U test, the Kruskal-Wallis test and multiple regression analyses. Power calculation was conducted in R Studio.

Results: Both All-on-4 and All-on-6 follow-up groups showed high scores in total satisfaction and PROMs, including chewing comfort, aesthetics, cleanability, and stability, with no significant difference (p > 0.05). Meanwhile, no significant differences were observed in the OHIP scores between two groups in both follow-up durations (p > 0.05). However, in patients with 3-5 years follow-up, All-on-4 group had significantly lower phonetic satisfaction scores than All-on-6 group (p < 0.05). Additionally, during both follow-up periods, All-on-4 patients exhibited notably superior psychological effect in contrast to All-on-6 patients (p < 0.05).

Conclusions: Edentulous patients treated by four or six implant-supported fixed prostheses showed same high satisfaction in oral health-related quality of life in both 3-5 years and 5-7 years follow-ups.