Abstract
Polymethyl methacrylate (PMMA) is widely used in clinical treatments in dentistry, e.g. denture base materials, temporary restoration, and orthodontic appliances. There are a wide variety of microbes in the oral cavity. As the surfaces of prostheses are exposed in the oral cavity, with nutrition from daily diet, bacteria and fungi are induced to adhere on surfaces of prostheses. Under accumulation, microbes form biofilms, which contribute to dental caries and periodontal diseases.
In clinical appliance, a specific set of functional properties are required for a polymeric material. Usually, it depends on biocompatibility of a material whether the material is qualified for medical use. Most polymeric materials are nontoxic and have sufficient mechanical properties to be biological materials. Surface modification is the mainstream method to improve polymeric materials due to its short development cycle.
In this research, we modified surfaces of PMMA, including chemical grafting poly(2-hydroxyethyl methacrylate) (PHEMA) and plasma grafting polyethylene glycol methacrylate (PEGMA), to study how surface modification affects bacterial adhesion. Functional groups, chemical bonds, hydrophilicity, and roughness on the surfaces were determined by Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS), contact angle, and Surfcorder respectively.
Furthermore, how zeta potential affects bacterial adhesion on PMMA and PMMA-PHEMA was studied. Biocompatibility of the modified samples of the human gingival fibroblasts (HGF) was evaluated by cell viability test with MTT assay. To analyze if the grafted materials are antibacterial, direct contact and bacteria adhesion tests were performed.
Results indicated that PMMA grafted with PHEMA shows increased hydrophilicity with decreased adhered bacteria while not killing nor inhibiting growth of bacteria. Besides, surfaces of PMMA-PHEMA are more negatively charged, which repells bacteria because their outer membrane is also negatively charged. MTT assay also showed better biocompatibility on PMMA-PHEMA. Therefore, we proved that grafting PHEMA onto PMMA prevents bacterial adhesion compared with PMMA only.
In clinical appliance, a specific set of functional properties are required for a polymeric material. Usually, it depends on biocompatibility of a material whether the material is qualified for medical use. Most polymeric materials are nontoxic and have sufficient mechanical properties to be biological materials. Surface modification is the mainstream method to improve polymeric materials due to its short development cycle.
In this research, we modified surfaces of PMMA, including chemical grafting poly(2-hydroxyethyl methacrylate) (PHEMA) and plasma grafting polyethylene glycol methacrylate (PEGMA), to study how surface modification affects bacterial adhesion. Functional groups, chemical bonds, hydrophilicity, and roughness on the surfaces were determined by Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS), contact angle, and Surfcorder respectively.
Furthermore, how zeta potential affects bacterial adhesion on PMMA and PMMA-PHEMA was studied. Biocompatibility of the modified samples of the human gingival fibroblasts (HGF) was evaluated by cell viability test with MTT assay. To analyze if the grafted materials are antibacterial, direct contact and bacteria adhesion tests were performed.
Results indicated that PMMA grafted with PHEMA shows increased hydrophilicity with decreased adhered bacteria while not killing nor inhibiting growth of bacteria. Besides, surfaces of PMMA-PHEMA are more negatively charged, which repells bacteria because their outer membrane is also negatively charged. MTT assay also showed better biocompatibility on PMMA-PHEMA. Therefore, we proved that grafting PHEMA onto PMMA prevents bacterial adhesion compared with PMMA only.
| Original language | Chinese (Traditional) |
|---|---|
| DOIs | |
| Publication status | Published - 2017 |
| Externally published | Yes |
