Clinical-Functional Efficacy of Individual Adaptation Caps for Retention and Fixation of Removable Prostheses in Patients with Complete Tooth Loss: A Prospective Randomised Controlled Trial
European Journal of Prosthodontics and Restorative Dentistry (2026) 34(2s),136–148
KeywordsIndividual adaptation cap; complete denture; denture adhesive; dental biomaterials; EVA polymer; oral biomaterial interface; prosthesis retention; edentulous patients
AuthorsAbstractBackground: Impaired retention is still a significant functional problem of conventional complete denture in patients with resorbed ridges, decreased salivary support and/or unstable denture-mucosa adaptation. Individual adaptation caps (IACs) produced by thermoforming ethylene vinyl acetate (EVAc) shell and tissue-conditioning mucosal contact layer could serve as patient-specific oral biomaterial interfaces for better retention and load distribution. Objective: To evaluate the clinical-functional efficacy, biomaterial tolerability, and therapeutic performance of IACs compared with standard complete dentures and denture adhesive in edentulous patients. Methods: A 120 completely edentulous patients were enrolled in a prospective, three-arm, parallel-group randomised controlled trial, where they were randomly assigned to one of three groups: standard complete denture alone, standard complete denture plus commercial denture adhesive, and standard complete denture plus IAC. Results were evaluated at baseline, 1 month, 3 months and 6 months and comprised prosthesis retention force, masticatory efficiency, OHIP-EDENT, patient satisfaction, mucosal health, prosthesis stability and adverse mucosal events. Results: At 6 months, the IAC group showed superior retention force compared with denture adhesive and standard denture groups (16.8 ± 2.7 N vs 9.2 ± 2.0 N and 7.1 ± 1.6 N; p < 0.001). Masticatory efficiency was also higher with IACs (74.1 ± 9.4% vs 55.4 ± 8.2% and 44.7 ± 7.1%; p <0.001). OHIP-EDENT scores decreased by 72.5% in the IAC group, while satisfaction reached 8.9 ± 0.7/10. Mucosal health and prosthesis stability were significantly improved, with no increase in adverse mucosal events. Conclusion: IACs provide a non-drug, biomaterial-based therapeutic interface that improves denture retention, function, mucosal health, and patient-reported outcomes. Their superiority over denture adhesive supports their clinical relevance for prosthodontic biomaterial research. 1. INTRODUCTION A significant number of adults in the world are completely toothless and the prevalence of complete dentures (CDs) varies across the world regions and age groups (from 7% to 40% of adults), that is tens of millions of people using CDs to restore oral function, aesthetics and phonation (Petersen & Yamamoto, 2005; Tyrovolas et al., 2016). Despite the advancements of implant based prosthetic rehabilitation, complete dentures are still the most common rehabilitative modality in resource•••••••••••••••••••••••••••••••• ejprd.org- Published by Riset Publishing Services LLC.
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