Impact of material type and acidic oral environment on physical properties and protein adsorption of subtractively and additively manufactured resin‐ceramics for definitive crowns

Abstract Purpose This study aimed to explore how material type and simulated acidic oral environment can affect the physical properties and protein adsorption of subtractively manufactured (SM) and additively manufactured (AM) resin–ceramic materials for definitive crowns. Materials and Methods Disk‐shaped specimens (Ø10 × 5 mm) were fabricated from an SM (Vita Enamic, VE) and an AM (Permanent Crown, PC) resin–ceramic material indicated for definitive crowns. Each specimen surface was finely polished. Twenty‐five specimens from each material were immersed in acidic artificial saliva (pH 5.0 ± 0.2) at 37 ° C for 7 days to simulate aging in an acidic oral environment. The non‐aged specimens ( n = 25 per material) served as controls. Surface roughness ( R a , S a ), microhardness (HV), and protein adsorption (OD) were evaluated. R a and S a were analyzed using two‐way aligned rank transform analysis of variance (ANOVA) tests, HV using a two‐way ANOVA, and OD using a factorial linear model with HC3 heteroskedasticity‐robust standard errors. Post hoc comparisons were performed using estimated marginal means with Sidak or Tukey adjustments, with the significance level set at α = 0.05. Results Aging significantly increased the R a and S a , whereas it decreased the HV for both materials ( p ≤ 0.013). VE had higher HV than PC ( p < 0.001). Although the OD of tested materials did not differ under non‐aged condition and aging did not affect the OD ( p ≥ 0.091), PC demonstrated greater OD than VE when aged in acidic saliva ( p = 0.039). Conclusions Although the roughness of tested materials remained below clinical thresholds, acidic aging increased surface irregularities and reduced the hardness. VE may be more resistant to wear and protein accumulation‐related complications than PC with acidic oral challenges.