Influence of Length of Occlusal Support on Masticatory Function of Free-End Removable Partial Dentures: Short-Term Adaptation

Purpose To analyze masticatory function after a short adaptation period relative to occlusal support length reduction in free‐end removable partial denture (RPD) wearers. Materials and Methods Twenty‐three patients (55.2 ± 8.4 years) were rehabilitated with maxillary complete and mandibular free‐end RPDs extending to the second molars. Five occlusal support length conditions were determined by removing artificial teeth from the RPDs: full occlusal support (control); occlusal support to the first molars, second premolars, and first premolars; and no occlusal support. To explore a probable short‐term adaptation to occlusal support length reduction, participants wore their dentures at each condition for a period of 1 week before starting masticatory function assessment. For this purpose, masticatory performance, masticatory efficiency, chewing rate, selection chance, and breakage function were evaluated at each condition using the sieving method. Data were analyzed using repeated‐measures ANOVA and post hoc Dunnett tests (α = 0.05). Results Masticatory performance and masticatory efficiency for 2 to 4 mm particles under the condition of occlusal support to the first molars and second premolars were similar to control values (p > 0.05). Masticatory efficiency relative to particles smaller than 2 mm was also seen at the condition of support length to the first premolars (p > 0.05). Chewing rates showed adaptation only at the condition of support length to the first molars (p > 0.05). A similar trend was noted for the selection chance of 8‐mm particles, and breakage function for 8‐ and 2.4‐mm particles (p > 0.05). Conclusion After a 1‐week adaptation period to free‐end RPDs with occlusal support lengths reduced to the premolars, participants were able to achieve adequate masticatory function.