Modifikacija svojstava stomatoprotetskih akrilata biocidnim agensima na bazi srebra
The research was based on the assumption that the modification ofcommercially available hot and cold polymerizing PMMA materialsby adding silver-based biocidal agents (silver nanoparticles - AgNPs;silver chloride - AgCl) results in their antimicrobial potential againstmicroorganisms that cause denture stomatitis, without potentiallytoxic effects on oral tissues. The goal of the research was to modifyand test the properties of hot and cold polymerizing PMMA(examination of the chemical structure, amount and distribution of thesilver-based biocidal agent; surface characteristics of the modifiedmaterials; the effect of the modification on the degree ofpolymerization, i.e. the amount of residual monomer; potential releaseof silver from the modified materials; biocompatibility testing in invitro conditions on cell cultures and testing the antimicrobial potentialof the modified materials against microorganisms isolated frompatients with prosthetic stomatitis as well as commercially availablestrains of C. albicans and S. aureus). The material was modified byincorporating different concentrations of AgNPs and AgCl (2%, 5%and 10% AgNPs, as well as 10% AgCl).The analysis of the composition of the oral flora of patients wearingmobile dental prostheses was performed by taking swabs from thebasal surface of the dental prostheses and the mucous membrane ofthe denture support on a sample of 15 patients with clinicallydiagnosed prosthetic stomatitis and an analogous control groupwithout clinical manifestations of this disease. The results of theanalysis of the composition of the oral flora of the denture supportingtissue in patients with denture stomatitis indicate the presence of C.albicans on the basal surfaces of mobile dentures as well as on thesurrounding oral tissue. The results of testing the chemical structureof modified PMMA materials indicate the incorporation of biocidalagents (AgNPs/AgCl) into the polymer chain with a better distributionof smaller sized biocidal agents (AgNPs). The color stability of themodified PMMA indicates a decrease in reflection, i.e. a significantdarkening of the modified materials (AgCl-PMMA CP is 90% darkerthan control, while AgNPs-PMMA CP is 130% darker thanunmodified PMMA CP; that is, AgCl-PMMA HP is 100% darker thancontrol, while AgNPs-PMMA HP is 200% darker than unmodifiedPMMA HP), so further work should be done to improve this property.The results of testing the degree of polymerization of modifiedPMMA materials indicate a decrease in the amount of residualmonomer in hot polymerizing PMMA, while modifying coldpolymerizing PMMA resulted in a decrease (10% AgNPs-PMMA)but also an increase in the amount of residual monomer (10% AgCl-PMMA). The release of silver from the modified materials did notoccur, so the antimicrobial effect can be explained by direct contactwith the tested microorganisms. The results indicate antimicrobialactivity against commercial strains of C. albicans and S. aureus aswell as C. albicans isolates. Regarding the investigation of the effectof modified hot and cold polymerizing AgNPs-PMMA and AgCl-PMMA on the viability and proliferation of L929 cells in cell culture,the results indicate their unchanged and optimal biocompatibilitycompared to the control and unmodified PMMA materials.The research resulted in chemically and antimicrobial effectivemodification of commercially available PMMA with biocidal agents,without affecting the viability and proliferation of cell culture. Thiscreated a good basis for further testing of modified materials in in vivoand clinical conditions, which would result in improved acrylatematerials for the production and readaptation of dental prostheses.Improving the properties of the materials available on the marketwould solve the problem of the prevalence of prosthetic stomatitis andenable its successful prevention and therapy, which would solve asignificant health and socioeconomic challenge.
Biografija autora: str. Bibliografija: str. 179-205 Datum odbrane: 16.10.2024. Prosthodontics, dental materials, microbiology, molecular biology
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