Implant-supported overdentures improve denture retention and patient satisfaction, but debonding of attachment housings from the denture base remains a frequent prosthetic complication. This in vitro study evaluated the influence of attachment-housing and denture-base materials on debonding occurrence and maximum tensile force in resin-cemented attachment housing denture-base complexes subjected to cyclic mechanical loading. Thirty standardized specimens were digitally designed and fabricated from three denture-base materials—polymethylmethacrylate (PMMA) (n = 12), polyetheretherketone (PEEK) (n = 12), and cobalt-chromium (Co-Cr) (n = 6)—and combined with either titanium or PEEK attachment housings, which were bonded with a dual-polymerized resin cement. The specimens were subjected to 1100 cycles of alternating tensile and compressive loading, and debonding occurrence and maximum tensile force were recorded. Debonding occurred in 60% of the specimens and differed significantly among denture base materials. No debond-ing was observed in the Co-Cr specimens, whereas debonding occurred in 75% of the PMMA and PEEK specimens. The Co-Cr specimens also demonstrated significantly higher maximum tensile force values than the PMMA and PEEK groups, while regarding the attachment-housing material, no significant main effect was detected. Within the limitations of this in vitro study, the denture-base material, fabrication, and surface treatment combinations significantly influenced debonding and tensile force during cyclic loading, whereas the attachment-housing material did not demonstrate a significant main effect.

Implant-supported overdentures improve denture retention and patient satisfaction, but debonding of attachment housings from the denture base remains a frequent prosthetic complication. This in vitro study evaluated the influence of attachment housing and denture base materials on debonding occurrence and maximum tensile force in resin-cemented attachment housing–denture base complexes subjected to cyclic mechanical loading. Thirty standardized specimens were digitally designed and fabricated from 3 denture base materials—polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), and cobalt-chromium (Co-Cr)—and combined with either titanium or PEEK attachment housings, which were bonded with a dual-polymerized resin cement. Specimens were subjected to 1,100 cycles of alternating tensile and compressive loading, and debonding occurrence and maximum tensile force were recorded. Debonding occurred in 60% of specimens and differed significantly among denture base materials, with no debonding observed in Co-Cr specimens, whereas debonding occurred in 75% of PMMA and PEEK specimens. Co-Cr specimens also demonstrated significantly higher maximum tensile force values than PMMA and PEEK groups, while attachment housing material showed no significant effect. Within the limitations of this in vitro study, the denture base material significantly influenced debonding and tensile force during cyclic loading, whereas the attachment housing material did not demonstrate a significant main effect.