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Characterization of mechanical and physicochemical properties of composite and glass-ionomer cements

dc.contributor.advisorAntonović, Dušan
dc.contributor.otherDimitrijević-Branković, Suzana
dc.contributor.otherUskoković, Petar
dc.contributor.otherMarinković, Aleksandar D.
dc.contributor.otherMilošević, Miloš
dc.creatorMitrović, Aleksandra
dc.date.accessioned2021-05-14T13:06:52Z
dc.date.available2021-05-14T13:06:52Z
dc.date.issued2020-09-15
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=8122
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:23635/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=37899529
dc.identifier.urihttps://nardus.mpn.gov.rs/handle/123456789/18300
dc.description.abstractU ovoj doktorskoj disertaciji ispitivana su mehaniþka i fiziþko-hemijska svojstva savremenih, komercijalno dostupnih dentalnih cemenata. Izvršena je uporedna analiza þetiri razliþita samovezujuüa dvojno-polimerizujuüa kompozitna cementa na bazi smole, Maxcem Elite (Kerr, USA), Relyx U200 (3M, ESPE, Germany), Multilink Automix (Ivoclar Vivadent, Liechtenstein) i SeT PP (SDI, Australia), glas-jonomer cementa Riva Luting (SDI, Australia) i samovezujuüeg glasjonomer cementa modifikovanog smolom Riva Luting Plus (SDI, Australia). Osnovna svrha izbora materijala razliþitog sastava i indikacija je bila da se obuhvate sve tri grupe trajnih dentalnih cemenata za adhezivnu tehniku cementiranja, kako bi se komparativnom karakterizacijom ispitala svojstva što šireg spektra materijala. Kompozitni cementi na bazi smole imaju izvanredna estetska svojstva, dobre mehaniþke i zadovoljavajuüe biološke karakteristike i koriste se za restauracije prednjih i boþnih zuba. Meÿutim, glavni nedostaci ove grupe materijala su polimerizaciona kontrakcija, nepotpuna konverzija monomera u polimer i veüi porast temperature tokom polimerizacije koji može da prouzrokuje termiþku traumu u pulpi. Usled polimerizacione kontrakcije, spoj zubnih tkiva i ispuna može biti ugrožen, pa se ova pojava smatra glavnim uzrokom nastanka mikroprslina, koja dalje omoguüava prodor pljuvaþke i mikroorganizama. Neizreagovani monomeri mogu da se naruše mehaniþka svojstva i biokompatiblnost ovih materijala. Glas-jonomer cementi (GJC) su materijali na bazi vode i jedini pravi samovezujuüi (samoadhezivni) materijali koji imaju antikariogeno dejstvo i sposobnost kontinuiranog oslobaÿanja fluora bez promene fiziþkih svojstava. GJC-i nemaju široko rasprostranjenu primenu kao kompozitni cementi na bazi smole zbog lošijih mehaniþkih svojstava i sporog vezivanja. Metodom trodimenzionalne korelacije digitalnih slika (3D DIC) izvršena su merenja von Mizesovih deformacija i pomeranja u svim ispitivanim materijalima. Takoÿe, kod ispitivanih materijala izmerena je mikrotvrdoüa po Vikersu, stepen konverzije i maksimalna temperatura koju ispitivani materijali dostižu tokom svetlosne polimerizacije LED lampom, primenom termoparova. Ispitana je morfologija karakteristiþnih oblasti ispitivanih dentalnih materijala razliþitog hemijskog sastava primenom skenirajuüe elektronske mikroskopije. Rezultati dobijeni 3D DIC metodom su pokazali da je kod svih ispitivanih materijala uoþeno nehomogeno deformaciono polje i da su veüe maksimalne vrednosti von Mizesovih deformacija u perifernom delu uzoraka, a manje maksimalne vrednosti u centralnom delu. Najveüe vrednosti maksimalnih deformacija imao je kompozitni cement Multilink Automix, a najmanje vrednosti pokazao je glas-jonomer Riva Luting. Na osnovu izmerenih vrednosti pomeranja za sve ispitivane kompozitne cemente dobijeno se usled polimerizacione kontrakcije materijala naspramna površina uzorka u odnosu na površinu uzorka osvetljenu LED lampom kontrahuje u pravcu centra mase materijala. Korišüenjem 3D DIC metoda izmerene su promene polja deformacija i posle preporuþenog vremena polimerizacije. Najveüe izmerene vrednosti pomeranja imao kompozitni cement Multilink Automix, a najmanje vrednosti pomeranja pokazao je kompozitni cement Relyx U200. Statistiþkom analizom dobijeno je da su vrednosti Mizesove deformacije u perifernom delu uzorka bile su u znaþajnoj korelaciji sa pomeranjem. Veüa vrednost deformacije je bila povezana i sa veüom vrednošüu pomeranja (Pearsonov koeficijent r=0,639; p<0,001). Pozitivna korelacija je registrovana i izmeÿu Mizesove deformacije u centralnom delu uzorka i pomeranjem (Pearsonov koeficijent r=0,493; p=0,006). Rezultati mikrotvrdoüe su pokazali najveüe vrednosti mikrotvrdoüe neposredno posle polimerizacije kod materijala Relyx U200, a nakon 24h najveüe vrednosti mikrotvrdoüe bile su kod materijala Riva Luting. Porast vrednosti mikrotvrdoüe bio je prisutan kodsvih ispitivanih materijala nakon 24h, što je ukazalo na dugotrajnu reakciju oþvršüavanja materijala. Statistiþkom analizom dobijeno je da su vrednosti Relyx U200, Maxcem Elite i Multilink Automix pokazali su statistiþki znaþajno veüe vrednosti tvrdoüe u poreÿenju sa materijalima Riva Luting i Riva Luting Plus, dok je SeT PP imao statistiþki znaþajno niže vrednosti tvrdoüe u odnosu na ostale dentalne cemente, osim Riva Luting (p<0,05). Nakon 24 h Riva Luting i Riva Luting Plus su pokazali statistiþki znaþajno veüu vrednost tvrdoüe u poreÿenju sa ostalim dentalnim cementima (p<0,05). Vrednosti tvrdoüe materijala Relyx U200 su bile statistiþki znaþajno veüe u odnosu na Multilink Automix, Maxcem Elite i SeT PP (p<0,05). SeT PP je, sliþno kao i u merenju neposredno posle polimerizacije, imao statistiþki najnižu vrednost tvrdoüe od svih ispitivanih materijala (p<0,05). Vrednosti tvrdoüe dentalnih cemenata neposredno posle polimerizacije i nakon 24 h nisu bile statistiþki znaþajno razliþite samo u sluþaju materijala Maxcem Elite (p>0,05). Svi ostali ispitivani materijali su imali statistiþki znaþajno veüe vrednosti mikrotvrdoüe nakon 24 h u odnosu na vrednosti dobijene neposredno posle polimerizacije (p<0,05). Ispitivani kompozitni materijali su pokazali znaþajno poveüanje konverzije nakon upotrebe LED lampe u trajanju od 20 s. Najveüe vrednosti stepena konverzije imali su Multilink Automix i Relyx U200, respektivno, što je i u skladu sa rezultatima dobijenim 3D DIC metodom korelacije digitalnih slika i mikrotvrdoüe po Vikersu. Mikografije ispitivanih materijala ukazuju na nehomogenu stukturu koja se sastoji od aglomerata veüih i manjih dimenzija, veliþine od 2 do 15 ȝm što znaþi da u ispitivanim materijalima punioci nisu monodisperzni. Svi ispitivani materijali su procentualno najviše imali veliþine preþnika þestica punioca u opsegu 1,0-2,0 ȝm...sr
dc.description.abstractThe aim of this doctoral dissertation is investigation of the mechanical, physical and chemical properties of contemporary, commercially available dental cements. Comparative analysis of four different self-adhesive resin based dual-curing composite cements, Maxcem Elite (Kerr, USA), Relyx U200 (3M, ESPE, Germany), Multilink Automix (Ivoclar Vivadent, Liechtenstein) and SeT PP (SDI, Australia), the glass-ionomer cement Riva Luting (SDI, Australia) and the self-adhesive resin-modified glass-ionomer Riva Luting Plus r (SDI, Australia) was performed. The main purpose of selection of material with different composition and indications was to cover all three groups of permanent dental cements for adhesive cementation, in order to investigate the properties of a wide range of materials by comparative characterization. Resin-based composite cements have outstanding aesthetic properties, good mechanical and acceptable biological characteristics and they are used for restorations of the anterior and lateral teeth. However, the major disadvantages of this material group are polymerization shrinkage, incomplete monomer to polymer conversion, and a higher temperature increase during polymerization that can cause thermal trauma to the pulp. Due to polymerization shrinkage, the contact area between dental tissues and restorative material can be compromised, and this phenomenon is considered to be the main cause of the marginal microcracks formation, which further allows penetration of saliva and microorganisms. Unreacted monomers can impair the mechanical properties and biocompatibility of these materials. Glass-ionomer cements (GJCs) are water-based materials and the only real self-adhesive materials that have anticarcinogenic effect and the ability to release fluorine continuously without changing physical properties. GJCs don’t have widespread application as resin-based composite cements due to poorer mechanical properties and slow bonding. Three-dimensional Digital Image Correlation (3D DIC) was used to measure von Mises strain and displacements in all tested materials. Also, Vickers micro hardness, the degree of conversion and the maximum materials’ temperature reached during LED light polymerization, using thermocouples was measured. The morphology of characteristic areas of the examined dental materials of different chemical composition was investigated using scanning electron microscopy (SEM). The results obtained with the 3D DIC method showed that in all the tested materials a nonhomogeneous strain field was observed. Also, maximum values of von Mises strain were observed in the peripheral part of the samples and smaller in the central part. Multilink Automix composite cement had the highest values of maximum strain, and the glass-ionomer Riva Luting showed the lowest strain values. Based on the measured displacement values for all tested composite cements, due to the polymerization shrinkage of the material, the opposite surface of the specimen relative to the specimen surface illuminated by the LED lamp shrinks towards the center of material mass. The changes in the deformation and displacement fields, even after the recommended polymerization time, were measured with 3D DIC method. Multilink Automix composite cement had the highest measured displacement values, and the Relyx U200 composite cement showed the lowest displacement values. Statistical analysis showed that Mises strain values in the peripheral part of the sample were significantly correlated with displacement. A higher deformation value was also associated with a higher displacement value (Pearson coefficient r = 0.639; p <0.001). A positive correlation was also registered between Mises deformation in the central part of the sample and displacement (Pearson coefficient r = 0.493; p = 0.006). The micro hardness results showed that material Relyx U200 had the highest micro hardness values immediately after polymerization, andafter 24 h the highest micro hardness values were found with the Riva Luting material. An increase in micro hardness values was present in all tested materials after 24 h, which indicated a longlasting material curing reaction. Statistical analysis showed that Relyx U200, Maxcem Elite and Multilink Automix values showed statistically significantly higher hardness values compared to Riva Luting and Riva Luting Plus materials, while SeT PP had statistically significantly lower hardness values compared to other dental cements except Riva Luting (p <0.05). After 24 h, Riva Luting and Riva Luting Plus showed significantly higher hardness values compared to other dental cements (p <0.05). The hardness values of material Relyx U200 were statistically significantly higher compared to Multilink Automix, Maxcem Elite and SeT PP (p <0.05). The SeT PP had statistically the lowest hardness value of all the materials tested (p <0.05). The hardness values of dental cements immediately after polymerization and after 24 h were not statistically significantly different except in the case of material Maxcem Elite (p> 0.05). All other tested materials had statistically significantly higher micro hardness values after 24 h than micro hardness values obtained immediately after polymerization (p <0.05). The tested composite materials showed a significant increase in conversion after using an LED lamp for 20 s. Multilink Automix and Relyx U200 had the highest degree of conversion, respectively, which is in compliance with the results obtained by the 3D DIC method and Vickers micro hardness. The micrographs of the tested materials indicate a nonhomogeneous structure consisting of agglomerates of larger and smaller sizes, ranging from 2 to 15 ȝm which means that the fillers in the tested materials are not mono dispersed. All tested materials had highest percent of the diameter filler particle in the range of 1.0–2.0 ȝm...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Технолошко-металуршки факултетsr
dc.rightsopenAccessen
dc.sourceУниверзитет у Београдуsr
dc.subjectkompozitni cementi na bazi smolesr
dc.subjectresin-based composite cementsen
dc.subjectglas-jonomer cementisr
dc.subjectpolimerizaciona kontrakcija, 3D korelacija digitalnih slikasr
dc.subjectdimenziona stabilnostsr
dc.subjectmikrotvrdoüasr
dc.subjectstepen konverzijesr
dc.subjectSEM, termoparovisr
dc.subjectglass-ionomer cementsen
dc.subjectpolymerization shrinkageen
dc.subject3D Digital Image Correlationen
dc.subjectdimensional stabilityen
dc.subjectmicro hardnessen
dc.subjectdegree of conversionen
dc.subjectSEM, thermocouplesen
dc.titleKarakterizacija mehaničkih i fizičko-hemijskih svojstava kompozitnih i glas-jonomernih cemenatasr
dc.title.alternativeCharacterization of mechanical and physicochemical properties of composite and glass-ionomer cementsen
dc.typePhD thesis
dc.rights.licenseBY-NC-ND
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/71427/Disertacija.pdf
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/71428/IzvestajKomisije28697.pdf
dc.identifier.rcubhttps://hdl.handle.net/21.15107/rcub_nardus_18300


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