Statement of problem

Current methods of evaluating denture retention lack clinical relevance because of simplified testing conditions and limited design innovation. Bioinspired features such as octopus-like suction cups (SCs) offer a promising solution but remain underinvestigated. A more realistic in vitro model incorporating a peripheral seal (PS), artificial saliva, and these novel designs is needed to better assess and enhance denture retention.

Purpose

The purpose of this in vitro study was to evaluate the influence of preload forces, PS simulation, and spatially distributed octopus-inspired SC surface modifications on the retention of maxillary complete dentures.

Material and methods

The investigation was conducted in 2 phases. In Phase I, 12 3-dimensionally (3D) printed maxillary dentures were divided into 2 groups (n=6) to assess the effect of a simulated PS. Group NO PS (control) lacked a PS, while Group PS incorporated a silicone-based PS created using a printed mold. Retention was measured using a vertical pull-off test under 2 preload forces (4 N and 10 N) with artificial saliva. In Phase II, 50 dentures were assigned to 5 groups (n=10): Smooth (smooth surface), PSC (palatal SCs), Peri-SC (peripheral SCs), Peri-NSC (peripheral negative suction cups), and Adhesive-smooth (smooth surface with adhesive). All dentures were tested using the same PS simulation and preload conditions with triplicate retention measurements. Data were analyzed using 2-way analysis of variance (ANOVA) and Tukey post hoc tests (α=.05).

Results

Retention significantly increased in the presence of a PS at both preload levels (P<.05). Higher preload forces enhanced retention across all groups. Adhesive-smooth exhibited the greatest retention (P<.001), Peri-NSCs outperformed the Peri-SCs, PSCs, and Smooth dentures.

Conclusions

The simulated PS method provides a more clinically relevant approach to denture retention testing. Bioinspired SC modifications significantly improved denture retention under varying preload conditions tested using the simulated PS. Peri-NSCs represent a promising design strategy for enhancing the retention and stability of maxillary complete dentures.