Hacemos una revisión de la perspectiva del uso a futuro de las nanopartículas de plata en práctica dental.Nanotechnology has been used for medical applications in several forms, including dental practice with the development of silver nanoparticles (Ag NPs) as a useful tool. The aim of this review was to identify the properties and appliances of Ag NPs in dental practice. Silver compounds and NPs have already been used as dental restorative material, endodontic retrofill cements, dental implants and caries inhibitory solution. Despite the effectiveness that Ag NPs has showed in dental practice, Ag NPs remain a controversial area of research with respect to their toxicity in biological and ecological systems. Therefore any application of Ag NPs in dentistry requires more studies. In order to avoided the toxicity of these materials Ag NPs can be temporarily used in dentistry

ARGUETA FIGUEROA, LILIANA

CUEVAS GUAJARDO, SAHAMANTA

GARCIA CONTRERAS, RENE

JIMENEZ MARTINEZ, ROCIO

MEJIA RUBALCAVA, CYNTHIA

Mendieta Zerón, Hugo

SANCHEZ REYNA, PAOLA ARISELDA

International Dental Journal

Repositorio Institucional de la Universidad Autónoma del Estado de México

International Dental Journaldoi: 10.1111/j.1875-595X.2011.00072.xPerspectives for the use of silver nanoparticles in dentalpracticeRene´ Garcı´a-Contreras1, Liliana Argueta-Figueroa1, Cynthia Mejı´a-Rubalcava1,Rocio Jime´nez-Martı´nez1, Sahamanta Cuevas-Guajardo1, Paola Ariselda Sa´nchez-Reyna1and Hugo Mendieta-Zeron21 Dental Research Center (CIEAO), Faculty of Dentistry, Autonomous University State of Mexico (UAEMex), Mexico; 2 Medical Research Center(CICMED), UAEMex, Mexico.Nanotechnology has been used for medical applications in several forms, including dental practice with the development ofsilver nanoparticles (Ag NPs) as a useful tool. The aim of this review was to identify the properties and appliances of Ag NPsin dental practice. Silver compounds and NPs have already been used as dental restorative material, endodontic retrofillcements, dental implants and caries inhibitory solution. Despite the effectiveness that Ag NPs has showed in dental practice,Ag NPs remain a controversial area of research with respect to their toxicity in biological and ecological systems. Thereforeany application of Ag NPs in dentistry requires more studies. In order to avoided the toxicity of these materials Ag NPs canbe temporarily used in dentistry.Key words: Silver nanoparticles, dental practice, applications of Ag NPsINTRODUCTIONNanotechnology, which concerns structures at thenanometer scale (1–100 nm), is considered as a vitalcurrent technology of the 21st century based on itseconomic and scientific potential. In 2008, the publicexpenditure of nanotechnology was 430 mmd com-pared to 25 mmd in 19971,2. Nanoparticles (NPs) havea greater surface-to-volume ratio (per unit mass) thannon-nanoscale particles of the same material, andtherefore are more reactive. Particles smaller than50 nm are subject to the laws of quantum physics3.In 2008 and 2009, silver production was 21 300 and21 400 tons, respectively, according to United StatesGeological Survey (USGS)4. Over the years, silvercompounds and NPs (Figure 1) have exhibited antibac-terial activity resulting in the widespread use of silvernanoparticles (Ag NPs) in bedding, washing machines,water purification, toothpaste, shampoo and rinse,nursing bottles, fabrics, deodorants, filters, kitchenutensils, toys and humidifiers5. Furthermore, silvercompounds and NPs6 have been studied for dentalapplications including dental restorative material7, end-odontic retrofill cement8, dental implants9, and cariesinhibitory solution10. The aim of this brief review was toidentify the properties and appliances of Ag NPs indentistry practice.ANTIMICROBIAL PROPERTIESMost of the studies have indicated that silver interactswith sulfhydryl groups of proteins and with DNA,altering hydrogen bonding, respiratory processes, DNAunwinding, cell-wall synthesis and cell division11,12. Atthe macro level, these interactions effectively producebacterial death13.It is recognized that Ag NPs have antimicrobialactivity against Gram-negative bacteria performing‘pits’ in the cell wall of the bacteria. Clearly, amembrane with such morphology exhibits a significantincrease in permeability, resulting in death of the cell.Overall, silver mainly induces denaturation and oxidi-zation for cell wall which lead to rupture of theinternal cell organelles, resulting in bacterialdeath14,15. Although bacterial cell lysis could be oneof the reasons for the observed antibacterial property,NPs also modulate the phosphotyrosine profile ofputative bacterial peptides, which could affect bacte-rial signal transduction and inhibit the growth of theorganisms16.ª 2011 FDI World Dental Federation 1REV I EW ART I C L EIt is worth noting that the antibacterial activity ofnanosilver is dominated by silver ions (Ag+ ions) whenfine Ag NPs (less than about 10 nm in averagediameter) are employed that release high concentra-tions of these ions. In contrast, when relatively largerAg NPs are used, the concentration of the releasedAg+ ions is lower17. Likewise, Ag NPs with average size14 ± 6 nm and Ag+ ions such as AgNO3, inhibit thegrowth of Escherichia coli 55 ± 8% and 100%,respectively (Table 1 shows the antimicrobial effect ofAg NPs).Furthermore, silver particles are also used as alter-native radiopacifier to get the necessary radiopacity tocalcium silicate cements (CSC) and assess the purity ofthe radiopacifying agents18. These nanomaterials,which can be prepared in a simple and cost-effectivemanner, may be suitable for the formulation of newtypes of bactericidal materials13.CARIES INHIBITORY PROPERTIESThe most common worldwide oral diseases are dentalcaries and periodontal diseases, 60–90%, according tothe World Health Organization (WHO)19. In Mexico,some authors estimate that such diseases affect 90%and 70% of the population, respectively20. In thisregard, the use of silver solution, specifically, silverdiamine fluoride (Ag [NH3] 2F) has been used as cariesinhibitor. In context, fluoride and silver interact syner-gistically to form fluorapatite. The first step is theformation of calcium fluoride (CaF2) and silver phos-phate (Ag3PO4) in a basic environment, the secondreaction is the subsequent dissociation of calcium andfluoride21.Experimental composite adhesives (ECAs) showedslower bacterial growth than those containing conven-tional adhesives, suggesting that ECAs can help preventenamel demineralization around their surfaces withoutcompromising physical properties22.RESTORATIVE MATERIALSWhereas restorative materials with a silver polymercompound have showed effective antimicrobial prop-erties on implant components against StreptococcusTable 1 Antimicrobial properties of Ag NPsGram-positive bacteria Streptococcus sanguis6Bacillus subtilis35Enterococcus faecalis35Staphylococcus aureus36Gram-negative bacteria Escherichia coli36Salmonella typhimurium35Shigella dysenteriae type 138Citrobacter sp37Pseudomona aeruginosa37Pseudomona fluorescens38Fungi Candida albicans39Fusarium oxysporum37Virus Arenavirus40Human immunodeficiency virus-142Murine norovirus41Hepatitis B virus42(a)(b)(c)Figure 1. Scanning Electron Microscope views of Ag NPs. Illustra-tion provided by Professor Rau´l Alberto Morales Luckie, Faculty ofChemistry, UAEMex.2 ª 2011 FDI World Dental FederationGarcı´a-Contreras et al.sanguis6, silver has been incorporated into glass iono-mer cements in order to improve the antibacterialproperties, including also, compressive, tensile strengthand creep resistance.Biofilms are surface-adherent populations of micro-organisms consisting of cells, water and extracellularmatrix material. Nanotechnology is a promising field ofscience which can guide our understanding of the roleof interspecies interaction in the development ofbiofilm. Streptococcus mutans with other species ofbacteria has been known to form dental biofilm. Thecorrelation between genetically modified bacteria Strep-tococcus mutans and nanoscale morphology has beenassessed using atomic force microscopy (AFMi). Occa-sionally, silver nanofibers have been attached to theimplant surfaces to reduce the need of using high dosesof antibiotics during the healing period, giving self-cleaning against plaque biofilm9.THERAPEUTICSNanostructures of different sizes, shapes and materialproperties have many applications in biomedical imag-ing, clinical diagnostics and therapeutics. In spite ofwhat has been achieved so far, a complete understand-ing of how cells interact with nanostructures of well-defined sizes, at the molecular level, remains poorlyunderstood.Gold and Ag NPs coated with antibodies can regulatethe process of membrane receptor internalization.The binding and activation of membrane receptorsand subsequent protein expression strongly depend onnanoparticle size. Although all NPs within the2–100 nm size range alter signaling processes essentialfor basic cell functions (including cell death) 7, 40- and50-nm NPs demonstrate the greatest effect. Theseresults show that NPs should no longer be viewed assimple carriers for biomedical applications, but can alsoplay an active role in mediating biological effects. Thesefindings may assist in the design of nanoscale deliveryand therapeutic systems and provide insights intonanotoxicity23.ADVERSE EFFECTSMetal ions are released from casting alloys and causedamage to cell structures and local inflammation.Ag(NH3)2F in contact to Human Gingival Fibroblast(HGF) for only one hour induced irreversible necrosis celldeath, whereas longer duration of contact with AgCl wasnecessary to induce this same effect. These data suggestthe importance of cautious application of Ag (NH3)2Finto the oral cavity24. Ag(NH3)2F shows much moresensibility at dose-dependent ion against three normalcells and three cancer line cells than AgCl (Figure 2a,b).Nanotoxicity is the toxicity imposed by nanomateri-als25. The toxic effects of Ag NPs are proportional tothe activity of free Ag+ ions released by the NPs26.Although NPs have tremendous potential for a host ofapplications, their adverse effects on living cells haveraised serious concerns for their use in the healthcareand consumer sectors. For example, NPs may be takenup directly into the brain by trans-synaptic transportand Ag NPs can enter via the blood-brain barrier andaccumulate in different regions of the brain and thismay be beneficial for drug delivery, increasing a risk tothe patient. It has also been reported that nanoparticleexposure can induce impairments to normal neuron-microglia microenviroment and even aggravate theprocess of brain pathology27.In support of the damage notion, in vitro cell linestudies have shown decreased mitochondrial functionafter exposure to Ag NPs in murine neuroblastomacells28, hepatic cells29, germline stem cells30, humanskin carcinoma31 and human epidermal keratinocytesand fibroblasts32, while in vivo studies showed thatexposure to NPs could result in an inflammation,oxidative stress, myocardial infarction and thrombosis33.HPLF(a)Ag(NH3)2F  (mM)HGFViabl cell number(%)(b)AgCl(mM)Figure 2. Cytotoxicity of Ag(NH3)F2 and AgCl against six cell lines,respectively. HPLF, human periodontal ligament ﬁbroblast cells;HGF, human gingival ﬁbroblast cells; HPC, human pulp cells andhuman oral squamous cells carcinoma obtained from differentpatients (HSC-2, 3, 4) were incubated for 24 h with the indicatedconcentrations of metal and then the relative viable cell number wasdetermined by MTT method. Each value represents the mean±S.D. oftriplicate assays. Reproducible results were obtained in further twoindependent experiments.ª 2011 FDI World Dental Federation 3Silver nanoparticles in dental practiceAs above mentioned, NPs could alter the permeabilityof blood brain barrier34.Exposure to Ag NPs has been associated with tissuedamage especially in liver. In rats, it has been deter-mined for Ag NPs a No Observable AdverseEffect Level (NOAEL) of 30 mg ⁄kg and the LowestObservable Adverse Effect Level (LOAEL) of125 mg ⁄kg35.NPs could also damage DNA causing deletions,mutations, single and double strand breakages, adductformation, and cross linking with proteins. Somestudies have confirmed DNA adducts and oxidationand induced DNA fragmentation following exposure tometal oxide NPs. In response to DNA insult, cellsattempt to repair damage DNA but repair failure maylead to cell death (apoptosis) or cell transformation. Inthe case of severe damage to DNA, cells may die byeither necrosis or apoptosis. In this regard, it has beenpublished previously that exposure to certain metaloxide NPs induces apoptosis36.Corrosion and discoloration of dental materials incontact with Ag NPs may be a concern. On the otherhand, antibacterial property carries with it a potentialenvironmental risk once these NPs are discharged intothe environment. Of particular concern, Ag+ ionsfrom AgNO3 inhibit the algae’s photosynthesis around18 times more than Ag NPs. However, over a longperiod, the NPs are even more toxic than the ionsalone37. These environmental concerns have led to adebate among advocacy groups and governments onwhether special regulation of nanotechnology is war-ranted.CONCLUSIONDespite the effectiveness that Ag NPs have showed indental practice, Ag NPs remain a controversial area ofresearch with respect to their toxicity in biological andecological systems38. Therefore any applications of AgNPs in dentistry requires more study. Initially, in orderto avoide the toxicity of these materials we think AgNPs can be used for temporary periods in the dentalfield.REFERENCES1. Harper TE, Holister P. The Nanotechnology OpportunityReport. 2nd edn, London: Cientifica; 2003.2. Roco M. Nanoscale science and engineering: unifying andtransforming tools. AIChE J 2004 50: 890–897.3. Auffan M, Rose J, Bottero JY et al. Towards a definition ofinorganic nanoparticles from an environmental, health and safetyperspective. Nat Nanotechnol 2009 4: 634–641.4. Kelly TD, Matos GR. Historical statistics for mineral and mate-rial commodities in the United States. 2010. Available from:http://minerals.usgs.gov/ds/2005/140/. Accessed 31 May 2011,18:04 PM.5. Maynard AD. Nanotechnology: A Research Strategy forAddressing Risk. Washington: Woodrow Wilson InternationalCenter for Scholars; 2006. Available from: http://www.tinhoahoc.com/Nanotechnology/RiskRelatedReseach_Maynard_7-06-Final.pdf. Accessed 31 May 2011, 18:04 PM.6. Slenters TV, Hauser-Gerspach I, Daniels AU et al. Silver coordi-nation compounds as light-stable, nano-structured and anti-bacterial coatings for dental implant and restorative materials.J Mater Chem 2008 18: 5359–5362.7. Jia H, Hou W, Wei L et al. The structures and antibacterialproperties of nano-SiO2 supported silver ⁄ zinc-silver materials.Dent Mater 2008 24: 244–249.8. Pissiotis E, Spangberg L. Reaction of bony tissue to implantedsilver glass ionomer and a reinforced zinc oxide-eugenol cement.Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000 89:623–629.9. Sheikh FA, Barakat NA, Kanjwal MA et al. Electrospun titaniumdioxide nanofibers containing hydroxyapatite and silver nano-particles as future implant materials. J Mater Sci Mater Med 201021: 2551–2559.10. Swift EJ Jr. In vitro caries-inhibitory properties of a silver cermet.J Dent Res 1989 68: 1088–1093.11. Lansdown AB. Silver in health care: antimicrobial effects andsafety in use. Curr Probl Dermatol 2006 33: 17–34.12. Oppermann RV, Johansen JR. Effect of fluoride and non-fluoridesalts of copper, silver and tin on the acidogenicity of dental pla-que in vivo. Scand J Dent Res 1980 88: 476–480.13. Wu MY, Suryanarayanan K, van Ooij WJ et al. Using microbialgenomics to evaluate the effectiveness of silver to prevent biofilmformation. Water Sci Technol 2007 55: 413–419.14. Lara HH, Ixtepan-Turrent L, Garza-Trevino EN et al. PVP-coated silver nanoparticles block the transmission of cell-free andcell-associated HIV-1 in human cervical culture. J Nanobiotech-nology 2010 8: 15.15. Sondi I, Salopek-Sondi B. Silver nanoparticles as antimicrobialagent: a case study on E. coli as a model for Gram-negativebacteria. J Colloid Interface Sci 2004 275: 177–182.16. Shrivastava S, Bera T, Singh SK et al. Characterization of anti-platelet properties of silver nanoparticles. ACS Nano 2009 3:1357–1364.17. Sotiriou GA, Pratsinis SE. Antibacterial activity of nanosilver ionsand particles. Environ Sci Technol 2010 44: 5649–5654.18. Camilleri J, Gandolfi MG. Evaluation of the radiopacity ofcalcium silicate cements containing different radiopacifiers. IntEndod J 2010 43: 21–30.19. World Health Organization. 2011. Available from: http://www.who.int/mediacentre/factsheets/fs318/en/index.html. Accessed31 May 2011, 18:04 PM.20. de la Fuente-Herna´ndez J, Gonza´lez de Cosı´o M, Ortega-Maldonado M et al. [Dental decay and tooth loss at the highschool level in Mexican students]. Salud Publica Mex 2008 50:235–240.21. Rosenblatt A, Stamford TC, Niederman R. Silver diamine fluoride:a caries ‘silver-fluoride bullet’. J Dent Res 2009 88: 116–125.22. Ahn SJ, Lee SJ, Kook JK et al. Experimental antimicrobialorthodontic adhesives using nanofillers and silver nanoparticles.Dent Mater 2009 25: 206–213.23. Jiang W, Kim BY, Rutka JT et al. Nanoparticle-mediated cellularresponse is size-dependent. Nat Nanotechnol 2008 3: 145–150.24. Contreras RG, Sakagami H, Nakajima H et al. Type of cell deathinduced by various metal cations in cultured human gingivalfibroblasts. In Vivo 2010 24: 513–517.25. Fadeel B, Garcia-Bennett AE. Better safe than sorry: under-standing the toxicological properties of inorganic nanoparticlesmanufactured for biomedical applications. Adv Drug Deliv Rev2010 62: 362–374.4 ª 2011 FDI World Dental FederationGarcı´a-Contreras et al.26. Park EJ, Yi J, Kim Y et al. Silver nanoparticles induce cytotoxicityby a Trojan-horse type mechanism. Toxicol In Vitro 2010 24:872–878.27. Yang Z, Liu ZW, Allaker RP et al. A review of nanoparticlefunctionality and toxicity on the central nervous system. J R SocInterface 2010 7(Suppl. 4): S411–S422.28. Schrand AM, Braydich-Stolle LK, Schlager JJ et al. Can silvernanoparticles be useful as potential biological labels? Nanotech-nol 2008 19: 104–119.29. Hussain SM, Hess KL, Gearhart JM et al. In vitro toxicity ofnanoparticles in BRL 3A rat liver cells. Toxicol In Vitro 2005 19:975–983.30. Braydich-Stolle L, Hussain S, Schlager JJ et al. In vitro cytotox-icity of nanoparticles in mammalian germline stem cells. ToxicolSci 2005 88: 412–419.31. Arora S, Jain J, Rajwade JM et al. Cellular responses induced bysilver nanoparticles: in vitro studies. Toxicol Lett 2008 179: 93–100.32. Burd A, Kwok CH, Hung SC et al. A comparative study of thecytotoxicity of silver-based dressings in monolayer cell, tissueexplant, and animal models. Wound Repair Regen 2007 15: 94–104.33. Kumar CSSR. Nanomaterials: toxicity, health and environmentalissues. Wiley-VCH, LA, USA: 2006; p. 96, 306–308.34. Zhao Y, Nalwa HS. Nanotoxicology. Stewenson Ranch, USA:American Scientific Publishers; 2006.35. Kim YS, Song MY, Park JD et al. Subchronic oral toxicity ofsilver nanoparticles. Part Fibre Toxicol 2010 7: 20.36. Huang YW, Wu C, Aronstam RS. Toxicity of Transition MetalOxide Nanoparticles: recent Insights from in vitro Studies.Materials 2010 3: 4842–4859.37. Navarro E, Piccapietra F, Wagner B et al. Toxicity of silvernanoparticles to Chlamydomonas reinhardtii. Environ Sci Tech-nol 2008 42: 8959–8964.38. Allaker RP. The use of nanoparticles to control oral biofilm for-mation. J Dent Res 2010 89: 1175–1186.39. Sadhasivam S, Shanmugam P, Yun K. Biosynthesis of silvernanoparticles by Streptomyces hygroscopicus and antimicrobialactivity against medically important pathogenic microorganisms.Colloids Surf B Biointerfaces 2010 81: 358–362.40. Speshock JL, Murdock RC, Braydich-Stolle LK et al. Interactionof silver nanoparticles with Tacaribe virus. J Nanobiotechnology2010 8: 19.41. De GB, Sintubin L, Baert L et al. Biogenic silver for disinfectionof water contaminated with viruses. Appl Environ Microbiol2010 76: 1082–1087.42. Lu L, Sun RW, Chen R et al. Silver nanoparticles inhibit hepatitisB virus replication. Antivir Ther 2008 13: 253–262.Correspondence to:Rene´ Garcı´a Contreras,Dental Research Center,Faculty of Dentistry,Autonomous University State of Mexico,Karatasca 604,Nueva Oxtotitlan 50100,Mexico.Email: dentist.garcia@gmail.comª 2011 FDI World Dental Federation 5Silver nanoparticles in dental practice

Perspectives for the use of silver nanoparticles in dental practice

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Perspectives for the use of silver nanoparticles in dental practice

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Repositorio Institucional de la Universidad Autónoma del Estado de México