Impact of Peracetic Acid and Cetylpyridinium Chloride Disinfection on Removable Partial Denture Materials

This in vitro study evaluated the effects of peracetic acid (PA, 0.25 mg/mL) and cetylpyridinium chloride (CPC, 0.5 mg/mL) solutions on the surfaces of heat-polymerized acrylic resin and cobalt-chromium alloy (Co-Cr). Heat-7 polymerized acrylic resin specimens, 90 (_ᴓ1_4_ _× _3_ _m_m_)_,_ _7_0_ _(65 × 10 × 3.3 mm), and 78 Co-Cr (_ᴓ1_2_ _× _3_ _m_m_)_ _underwent daily 10-minute immersions for periods simulating roughly 3 years (8-23 days) or 5 years (13-38 days) in: distilled water (8/13 days), CPC 10 (23/38 days), or PA (8/13 days). Evaluated parameters for acrylic resin included: surface 11 r_o_u_g_h_n_e_s_s_ _(_R_a_,_ _μm_)_,_ _Knoop Hardness (HK, kgf/mm²), c_o_l_o_r_ _c_h_a_n_g_e_ _(_ΔE_)_,_ _a_n_d_ _f_l_e_x_u_r_a_l_ _strength (MPa). For Co-Cr, were assessed: Ra, gloss change (ΔGU), and chemical degradation and surface topography using a scanning electron microscope (SEM). Data were analyzed by ANOVA, Wald Test, and Kruskal-W_a_l_l_i_s_ _f_o_l_l_o_w_e_d_ _b_y_ _D_u_n_n_'_s_ _t_e_s_t_ _(_α _=_ _0.05). PA enhanced resin flexural strength. CPC induced minor resin discoloration post 3 years (p=0.015). For Co-Cr, after 5 years, roughness values rose significantly in both CPC and PA immersions, PA also enhanced corrosion resistance through the formation of a more stable passivation layer. PA proved promising as a disinfectant for removable partial denture, suggesting a new clinical application due to its high oxidative potential. PA prosthesis disinfection in laboratories is recommended, considering positive impact on preserving mechanical properties and preventing metal alloy corrosion.