Youbo Liu,1,2 Zhongke Wang,1,2 Xiangrui Liu,1,2 Hongmei Chen,1,2 Ying Huang,1,2 Aodi Li,1,2 Yifan Pu,1,2 Ling Guo1,2 

1Department of Oral Prosthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, People’s Republic of China; 2Luzhou Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Luzhou, People’s Republic of China

Correspondence: Ling Guo, Department of Oral Prosthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, People’s Republic of China, Tel +86-15892900789, Email glsmiling@swmu.edu.cn

Statement of Problem: The high recurrence rate of denture stomatitis may be related to the strong resistance of fungi. Therefore, the method of providing biomaterials with antifungal properties is an attractive solution for improving microbial control.
Purpose: Against the drug resistance of Candida albicans, this study aim to elucidate the photocatalytic antibacterial effect of TiO2-HAP nanocomposite-modified PMMA on Candida albicans through in vitro experiments, and to evaluate the potential impact of the mechanical properties, optical properties, cytotoxicity and contact angle of the modified PMMA, to provide a scientific basis for the development of denture base resins with minimum percentage of photocatalytic additives.
Methods: In this study, TiO2-HAP nanoparticles were mixed with self-polymerized PMMA in different mass ratios, 0%wt was the control group. Various methods were used to characterize TiO2-HAP. Subsequently, the changes in mechanical and optical properties of the samples were measured, and Cell Counting Kit-8 (CCK-8) and cell live-death staining were used to detect the cytotoxicity of the samples to human gingival fibroblasts (HGFs) in vitro. The contact angle of the specimens was evaluated. The photocatalytic antibacterial activity of modified PMMA against Candida albicans was studied using a biofilm accumulation test and scanning electron microscopy.
Results: TiO2-HAP nanocomposites have an acceptable structure. When the addition amount of TiO2-HAP is 1.0%wt, the PMMA material showed peak mechanical properties. When the additional amount is less than 1%wt, The patient is still aesthetically acceptable PMMA showed no significant cytotoxicity at doses below 2%wt. While TiO2-HAP modified PMMA containing only 1%wt showed up to 94% antibacterial efficiency against Candida albicans under visible light.
Conclusion: Therefore, it is inferred that the optimal photocatalytic antimicrobial and mechanical properties of PMMA materials are achieved by adding 1%wt TiO2-HAP without causing significant changes in cytotoxicity and optical properties.

Keywords: TiO2-HAP, polymethyl methacrylate, photodynamic therapy, Candida albicans, antibiofilm