Mehaničke i kemijske karakteristike kompozitnih materijala funkcionaliziranih bioaktivnim staklom smanjenog udjela natrija i obogaćenog fluoridima

doctoral thesis

• Title (english): Mechanical and chemical characteristics of resin composites funcionalized with a low-sodium fluoride-containing bioactive glass
• Author: Alen Muradbegović
• Mentor: Danijela Marović (mentor)
• Committee member: Zrinka Tarle (predsjednik povjerenstva)
• Committee member: Jurica Matijević (član povjerenstva)
• Committee member: Iva Šrut Rakić (član povjerenstva)
• Granter: University of Zagreb; School of Dental Medicine; Zagreb
• Defense date and country: 2023-12-20, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Dental Medicine
• Universal decimal classification (UDC): 616.31 - Stomatology

Abstract

Ciljevi ovog istraživanja bili su: (I) dizajnirati seriju eksperimentalnih kompozitnih materijala s inkrementnim povećanjem težinskog udjela (5 – 40 %) novosintetiziranog bioaktivnog stakla (N-BG), (II) usporediti reaktivno punilo N-BG s konvencionalnim bioaktivnim staklom (45S5- BG) u sastavu eksperimentalnih kompozitnih materijala i (III) ispitati mehaničke i kemijske promjene materijala kao posljedice umjetnog starenja. Makromehanička svojstva (savojna čvrstoća i modul) te mikromehaničko... More svojstvo (mikrotvrdoća prema Vickersu) izmjereni su jedan dan nakon polimerizacije i nakon umjetnog starenja imerzijom u vodi i termocikliranjem. Apsorpcija vode i topljivost izmjereni su prema protokolu ISO 4049, a precipitacija kalcijevog fosfata ispitana je pomoću skenirajuće elektronske mikroskopije, energetski disperzivne rendgenske spektroskopije i infracrvene spektroskopije s Fourierovom transformacijom. Kod kompozitnih materijala s dodatkom 45S5-BG opaženo je značajno smanjenje makromehaničkih i mikromehaničkih svojstava s povećanjem udjela bioaktivnog stakla. Nasuprot tome, kompozitni materijali s dodatkom N-BG-a pokazali su značajno postojanija makromehanička svojstva, dok je za mikromehanička svojstva čak opaženo i statistički značajno poboljšanje pri većim težinskim udjelima N-BG-a (20 – 40 %). Apsorpcija vode bila je statistički značajno
izraženija kod kompozitnih materijala s 45S5-BG, povećavajući se 7 puta u usporedbi s kontrolnim materijalom, dok je za N-BG povećanje apsorpcije vode u usporedbi s kontrolom bilo samo dvostruko. Topljivost se povećala pri većim količinama bioaktivnog stakla, s naglim porastom za težinske udjele 45S5-BG od 20 do 40 %. Kalcijev fosfat precipitiran je na površinama svih kompozitnih materijala s težinskim udjelima bioaktivnog stakla od 10 % ili više. Poboljšana svojstva kompozitnih materijala funkcionaliziranih dodatkom N-BG-a ukazuju na bolju mehaničku, kemijsku i dimenzijsku stabilnost bez ugrožavanja mogućnosti
taloženja kalcijevog fosfata. S obzirom na poboljšana mehanička svojstva uz očuvanu bioaktivnost, N-BG predstavlja višestruke prednosti za upotrebu kao funkcionalno punilo remineralizirajućih kompozitnih materijala u usporedbi s tradicionalnim bioaktivnim staklom 45S5-BG. Less

Abstract (english)

Aims: The aims of this study were as follows: (I) to design a series of experimental composite materials with incremental increases in the filler ratios (5-40 wt%) of newly synthesized bioactive glass (N-BG), (II) to compare the reactive N-BG filler with conventional bioactive glass (45S5-BG) in the experimental composite materials, and (III) to examine the mechanical
and chemical changes of the materials that occur as a result of artificial ageing. Materials and methods: Macromechanical... More properties (flexural strength and modulus) and micromechanical properties (Vickers microhardness) were measured one day following polymerization and following artificial ageing by immersion in water and thermocycling. The ISO 4049 protocol was used to measure water sorption and solubility, while scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy were used to examine calcium phosphate precipitation.
Results: A significant decrease in macromechanical and micromechanical properties was observed in composite materials containing 45S5-BG as the ratio of bioactive glass increased. In contrast, composite materials containing N-BG showed significantly more stable macromechanical properties, with statistically significant improvements in micromechanical
properties observed at higher fractions of N-BG (20-40 wt%). Water sorption was significantly greater in composite materials containing 45S5-BG, increasing sevenfold when compared to the control material, whereas for N-BG, the increase in water sorption was only twofold. Solubility increased with increasing levels of bioactive glass, with 45S5-BG fractions of 20-40 wt% showing the greatest rise. Calcium phosphate was precipitated on the surfaces of all composite materials containing 10 wt% or more bioactive glass fractions.
Conclusion: Improved properties of N-BG-functionalized composite materials indicate better mechanical, chemical and dimensional stability without compromising the potential for calcium phosphate precipitation. Compared to more conventional bioactive glass 45S5-BG, N-BG offers a number of advantages for use as a functional filler in remineralizing composite materials due to its improved mechanical properties with preserved bioactivity. Less

• Keywords: stomatološki materijali; kompozitne smole; fluoridikalcij fosfat
• Keywords (english): Dental Materials; Composite Resins; Fluorides; Calcium Phosphates
• Language: croatian
• URN:NBN: urn:nbn:hr:127:626624
• Promotion: 2024
• Study programme: Title: Dental medicine; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti u području biomedicine i zdravstva (doktor/doktorica znanosti u području biomedicine i zdravstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-10-07 11:13:11