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Antimicrobial effects of nano titanium dioxide and disinfectants on maxillofacial silicones

  • Pinar Cevik
    Corresponding author: Dr Pinar Cevik, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara 06510, TURKEY
    Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey; and Research Scholar, Department of General Practice and Dental Public Health, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, Texas
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  • Gulcin Akca
    Professor, Department of Medical Microbiology, Faculty of Dentistry, Division of Basic Sciences, Gazi University, Ankara, Turkey
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  • Neset Volkan Asar
    Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
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  • Emine Avci
    Epidemiologist, General Directorate of Public Health, Turkish Ministry of Health, Turkey
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  • Sudarat Kiat-amnuay
    Professor and Section Head, Department of General Practice and Dental Public Health, Houston Center for Biomaterials and Biomimetics, The University of Texas Health Science Center at Houston School of Dentistry, Houston, Texas
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  • Burak Yilmaz
    Associate Professor, Department of Reconstructive Dentistry and Gerodontology, and Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland; and Adjunct Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio
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      Statement of problem

      Deficient hygiene of maxillofacial prostheses can be a source of infection, and various disinfectants, including nano-oxides, have been suggested for the disinfection of silicone prostheses. While maxillofacial silicones involving nano-oxides at different sizes and concentrations have been evaluated in terms of their mechanical and physical properties, reports are lacking on the antimicrobial effect of nano titanium dioxide (TiO2) incorporated into maxillofacial silicones contaminated by different biofilms.


      The purpose of this in vitro study was to evaluate the antimicrobial effects of 6 different disinfectants and nano TiO2 incorporation into maxillofacial silicone contaminated with Staphylococcus aureus, Escherichia coli, and Candida albicans biofilms.

      Material and methods

      A total of 258 silicone specimens (129 pure silicones and 129 nano TiO2-incorporated silicones) were fabricated. Specimens in each silicone group (with or without nano TiO2) were divided into 7 disinfectant groups (control, 0.2% chlorhexidine gluconate, 4% chlorhexidine gluconate, 1% sodium hypochlorite, neutral soap, 100% white vinegar, and effervescent) in each biofilm group. Contaminated specimens were disinfected, and the suspension of each specimen was incubated at 37 °C for 24 hours. Proliferated colonies were recorded in colony-forming units per mL (CFU/mL). The differences in microbial levels among specimens were evaluated to test the effect of the type of silicone and the disinfectant (α=.05).


      Significant difference was found among disinfectants regardless of the silicone type (P<.05). Nano TiO2 incorporation showed an antimicrobial effect on S aureus, E coli, and C albicans biofilms. Nano TiO2 incorporated silicone cleaned with 4% chlorhexidine gluconate had statistically less C albicans than pure silicone. Using white vinegar or 4% chlorhexidine gluconate led to no E coli on either silicone. Nano TiO2 incorporated silicone cleaned with effervescent had fewer S aureus or C albicans biofilms.


      The tested disinfectants and nano TiO2 incorporation into silicone were effective against most of the microorganisms used in this study.
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        • Han Y.
        • Kiat-amnuay S.
        • Powers J.M.
        • Zhao Y.
        Effect of nano-oxide concentration on the mechanical properties of a maxillofacial silicone elastomer.
        J Prosthet Dent. 2008; 100: 465-473
        • Guiotti A.M.
        • Goiato M.C.
        • Dos Santos D.M.
        Evaluation of the shore a hardness of silicone for facial prosthesis as to the effect of storage period and chemical disinfection.
        J Craniofac Surg. 2010; 21: 323-327
        • Guiotti A.M.
        • Cunha B.G.
        • Paulini M.B.
        • et al.
        Antimicrobial activity of conventional and plant-extract disinfectant solutions on microbial biofilms on a maxillofacial polymer surface.
        J Prosthet Dent. 2016; 116: 136-143
        • Kiat-Amnuay S.
        • Mekayarajjananonth T.
        • Powers J.M.
        • Chambers M.S.
        • Lemon J.C.
        Interactions of pigments and opacifiers on color stability of MDX4-4210/type A maxillofacial elastomers subjected to artificial aging.
        J Prosthet Dent. 2006; 95: 249-257
        • Guiotti A.M.
        • Goiato M.C.
        • Dos Santos D.M.
        • et al.
        Comparison of conventional and plant-extract disinfectant solutions on the hardness and color stability of a maxillofacial elastomer after artificial aging.
        J Prosthet Dent. 2016; 115: 501-508
        • Cevik P.
        • Eraslan O.
        Effects of the addition of titanium dioxide and silaned silica nanoparticles on the mechanical properties of Maxillofacial Silicones.
        J Prosthodont. 2017; 26: 611-615
        • Nikawa H.
        • Hamada T.
        • Yamamoto T.
        Denture plaque - Past and recent concerns.
        J Dent. 1998; 26: 299-304
        • Sheen S.R.
        • Harrison A.
        Assessment of plaque prevention on dentures using an experimental cleanser.
        J Prosthet Dent. 2000; 84: 594-601
        • Cevik P.
        • Polat S.
        • Duman A.N.
        Effects of the addition of titanium dioxide and silaned silica nanoparticles on the color stability of a maxillofacial silicone elastomer submitted to artificial aging.
        Cumhur Dent J. 2016; 19: 9-15
        • Mirabedini S.M.
        • Mohseni M.
        • PazokiFard S.
        • Esfandeh M.
        Effect of TiO2 on the mechanical and adhesion properties of RTV silicone elastomer coatings.
        Colloids Surfaces A Physicochem Eng Asp. 2008; 317: 80-86
        • Allaker R.P.
        Critical review in oral biology & medicine: The use of nanoparticles to control oral biofilm formation.
        J Dent Res. 2010; 89: 1175-1186
        • Sondi I.
        • Salopek-Sondi B.
        Silver nanoparticles as antimicrobial agent: A case study on E. coli as a model for Gram-negative bacteria.
        J Colloid Interface Sci. 2004; 275: 177-182
        • Besinis A.
        • De Peralta T.
        • Handy R.D.
        The antibacterial effects of silver, titanium dioxide and silica dioxide nanoparticles compared to the dental disinfectant chlorhexidine on Streptococcus mutans using a suite of bioassays.
        Nanotoxicology. 2014; 8: 1-16
        • Adams L.K.
        • Lyon D.Y.
        • Alvarez P.J.J.
        Comparative eco-toxicity of nanoscale TiO2, SiO2, and ZnO water suspensions.
        Water Res. 2006; 40: 3527-3532
        • Goiato M.C.
        • Rossatti Zucolotti B.C.
        • Mancuso D.N.
        • Dos Santos D.M.
        • Pellizzer E.P.
        • Ramos Verri F.
        Care and cleaning of maxillofacial prostheses.
        J Craniofac Surg. 2010; 21: 1270-1273
        • Filié Haddad M.
        • Coelho Goiato M.
        • Micheline dos Santos D.
        • Moreno A.
        • Filipe D’almeida N.
        • Alves Pesqueira A.
        Color stability of maxillofacial silicone with nanoparticle pigment and opacifier submitted to disinfection and artificial aging.
        J Biomed Opt. 2011; 16095004
        • Goiato M.C.
        • Haddad M.F.
        • dos Santos D.M.
        • Pesqueira A.A.
        • Moreno A.
        Hardness evaluation of prosthetic silicones containing opacifiers following chemical disinfection and accelerated aging.
        Braz Oral Res. 2010; 24: 303-308
        • Ariani N.
        • Visser A.
        • Teulings M.R.I.M.
        • et al.
        Efficacy of cleansing agents in killing microorganisms in mixed species biofilms present on silicone facial prostheses—an in vitro study.
        Clin Oral Investig. 2015; 19: 2285-2293
        • Barnabé W.
        • De Mendonça Neto T.
        • Pimenta F.C.
        • Pegoraro L.F.
        • Scolaro J.M.
        Efficacy of sodium hypochlorite and coconut soap used as disinfecting agents in the reduction of denture stomatitis, Streptococcus mutans and Candida albicans.
        J Oral Rehabil. 2004; 31: 453-459
        • Shi Y.
        • Song W.
        • Feng Z.H.
        • et al.
        Disinfection of maxillofacial silicone elastomer using a novel antimicrobial agent: Recombinant human beta-defensin-3.
        Eur J Clin Microbiol Infect Dis. 2009; 28: 415-420
        • Machado de Andrade I.
        • Cruz P.C.
        • Silva-Lovato C.H.
        • de Souza R.F.
        • Cristina Monteiro Souza-Gugelmin M.
        • de Freitas Oliveira Paranhos H.
        Effect of chlorhexidine on denture biofilm accumulation.
        J Prosthodont. 2012; 21: 2-6
        • Pavarina A.C.
        • Pizzolitto A.C.
        • Machado A.L.
        • Vergani C.E.
        • Giampaolo E.T.
        An infection control protocol: Effectiveness of immersion solutions to reduce the microbial growth on dental prostheses.
        J Oral Rehabil. 2003; 30: 532-536
        • Ellepola A.N.B.
        • Samaranayake L.P.
        Oral candidal infections and antimycotics.
        Crit Rev Oral Biol Med. 2000; 11: 172-198
        • Ferreira M.Á.F.
        • Pereira-Cenci T.
        • Rodrigues de Vasconcelos L.M.
        • Rodrigues-Garcia R.C.M.
        • Del Bel Cury A.A.
        Efficacy of denture cleansers on denture liners contaminated with Candida species.
        Clin Oral Investig. 2009; 13: 237-242
        • Eleni P.N.
        • Krokida M.K.
        • Polyzois G.L.
        • Gettleman L.
        Dynamic mechanical thermal analysis of maxillofacial prosthetic elastomers: The effect of different disinfecting aging procedures.
        J Craniofac Surg. 2014; 25: e251-e255
        • Moon A.
        • Powers J.M.
        • Kiat-Amnuay S.
        Color stability of denture teeth and acrylic base resin subjected daily to various consumer cleansers.
        J Esthet Restor Dent. 2014; 26: 247-255
        • Beyerle M.P.
        • Hensley D.M.
        • Bradley D.V.J.
        • Schwartz R.S.
        • Hilton T.J.
        Immersion disinfection of irreversible hydrocolloid impressions with sodium hypochlorite. Part I: Microbiology.
        Int J Prosthodont. 1994; 7: 234-238
        • Bell J.A.
        • Brockmann S.L.
        • Feil P.
        • Sackuvich D.A.
        The effectiveness of two disinfectants on denture base acrylic resin with an organic load.
        J Prosthet Dent. 1989; 61: 580-583
        • Chau V.B.
        • Saunders T.R.
        • Pimsler M.
        • Elfring D.R.
        In-depth disinfection of acrylic resins.
        J Prosthet Dent. 1995; 74: 309-313
        • Rutala W.A.
        • Weber D.J.
        Uses of inorganic hypochlorite (bleach) in health-care facilities.
        Clin Microbiol Rev. 1997; 10: 597-610
        • Pesqueira A.A.
        • Goiato M.C.
        • Dos Santos D.M.
        • Haddad M.F.
        • Moreno A.
        Effect of disinfection and accelerated ageing on dimensional stability and detail reproduction of a facial silicone with nanoparticles.
        J Med Eng Technol. 2012; 36: 217-221
        • Cevik P.
        • Yildirim-Bicer A.Z.
        Effect of different types of disinfection solution and aging on the hardness and colour stability of maxillofacial silicone elastomers.
        Int J Artif Organs. 2018; 41: 108-114
        • Laux C.
        • Peschel A.
        • Krismer B.
        Staphylococcus aureus colonization of the human nose and interaction with other microbiome members.
        Microbiol Spectr. 2019; 7 (p. 2, 4)
        • Hong S.W.
        • Kim M.R.
        • Lee E.Y.
        • et al.
        Extracellular vesicles derived from Staphylococcus aureus induce atopic dermatitis-like skin inflammation.
        Allergy Eur J Allergy Clin Immunol. 2011; 66: 351-359
        • De Paula Pereira R.
        • Lucas M.G.
        • Spolidorio D.M.P.
        • Filho J.N.A.
        Antimicrobial activity of disinfectant agents incorporated into type IV dental stone.
        Gerodontology. 2012; 29: e267-e274
        • Mat-Rani S.
        • Chotprasert N.
        • Srimaneekarn N.
        • Choonharuangdej S.
        Fungicidal effect of lemongrass essential oil on Candida albicans biofilm pre-established on maxillofacial silicone specimens.
        J Int Soc Prev Community Dent. 2021; 11: 525-530
        • Cousins B.G.
        • Allison H.E.
        • Doherty P.J.
        • et al.
        Effects of a nanoparticulate silica substrate on cell attachment of Candida albicans.
        J Appl Microbiol. 2007; 102: 757-765
        • Haghighi F.
        • Mohammadi S.H.R.
        • Mohammadi P.
        • Eskandari M.
        • Hosseinkhani S.
        The evaluation of Candida albicans biofilms formation on silicone catheter, PVC and glass coated with titanium dioxide nanoparticles by XTT method and ATPase assay.
        Bratisl Lek Listy. 2012; 113: 707-711
        • Salvia A.C.R.D.
        • Matilde F.D.S.
        • Rosa F.C.S.
        • et al.
        Disinfection protocols to prevent cross-contamination between dental offices and prosthetic laboratories.
        J Infect Public Health. 2013; 6: 377-382
        • Basman A.
        • Peker I.
        • Akca G.
        • Alkurt M.T.
        • Sarikir C.
        • Celik I.
        Evaluation of toothbrush disinfection via different methods.
        Braz Oral Res. 2016; 30: 4
        • Akay C.
        • Cevik P.
        • Karakis D.
        • Sevim H.
        In vitro cytotoxicity of maxillofacial silicone elastomers: Effect of nano-particles.
        J Prosthodont. 2018; 27: 584-587
        • Wei C.
        • Lin W.Y.
        • Zainal Z.
        • et al.
        Bactericidal activity of tio2 photocatalyst in aqueous media: Toward a solar-assisted water disinfection system.
        Environ Sci Technol. 1994; 28: 934-938
        • Jones N.
        • Ray B.
        • Ranjit K.T.
        • Manna A.C.
        Antibacterial activity of ZnO nanoparticle suspensions on a broad spectrum of microorganisms.
        FEMS Microbiol Lett. 2008; 279: 71-76
        • Franklin N.M.
        • Rogers N.J.
        • Apte S.C.
        • Batley G.E.
        • Gadd G.E.
        • Casey P.S.
        Comparative toxicity of nanoparticulate ZnO, bulk ZnO, and ZnCl2 to a freshwater microalga (Pseudokirchneriella subcapitata): The importance of particle solubility.
        Environ Sci Technol. 2007; 41: 8484-8490
        • Dizaj S.M.
        • Lotfipour F.
        • Barzegar-Jalali M.
        • Zarrintan M.H.
        • Adibkia K.
        Antimicrobial activity of the metals and metal oxide nanoparticles.
        Mater Sci Eng C Mater Biol Appl. 2014; 44: 278-284
        • Goiato M.C.
        • Haddad M.F.
        • Pesqueira A.A.
        • Moreno A.
        • dos Santos D.M.
        • Bannwart L.C.
        Effect of chemical disinfection and accelerated aging on color stability of maxillofacial silicone with opacifiers.
        J Prosthodont. 2011; 20: 566-569