BIocompatibility investigation of nanosynthesized materials based on calcium silicates and its impact on pulpo-periodontal tissue

Abstract

Introduction: Biocompatibility is interpreted as the material's ability to act within the adequate host response in a specific situation. The host’s response to foreign body will depend on its chemical reactivity, surface structure and topography. It has been shown that nanostructured surface more closely mimic the hierarchical organization of the bone tissue in comparison to microstructured, by increasing the concentration of active biomolecules that may affect cell migration, adhesion, differentiation and proliferation. During the nineties, mineral trioxide aggregate (MTA) was presented as a material of choice for retrograde fillings because of its lower apical microleakage, setting in the presence of moisture and high pH. Despite some favorable properties, MTA exhibits dry consistency, low flowability and long setting time which limit its clinical use. The aim of this study was to synthesize nanostructured materials based on highly active calcium silicates with enhanced properties and analyze their biocompatibility and bioactivity in comparison to MTA+ (Cerkamed, Stalowa Wola- Poland). Materials and Methods: The sol-gel method in a combination with hightemperature self-propagating reaction was applied for the synthesis of investigated materials. Phase analysis of investigated materials before and after hydratation was performed by XRD and FTIR, while the morphology of the samples was studied by SEM and EDS. The pH measurements were performed using pH-meter, while the amount of released ions was determined using ICP-OES. Biocompatibility of fresh investigated materials and their elutes (24h, 7 and 21 day) was conducted using indirect (MTT), direct test (LDH), proliferation test (3H-thymidine) and direct method (Neutral red). The interaction of directly applied investigated materials with dental pulp tissue was analyzed in an entire human tooth culture model (15 and 30 days). Eighteen guinea pigs received intramuscular sterile polyethylene tubes filled with investigated materials (15, 30 and 60 days). For intraosseous implementation twelve New Zealand white rabbits, divided into two groups (30 and 90 days) were used. Four calvary defects per animal were created with trepan burs and filled with freshly prepared investigated materials. The occurrence of inflammatory responses and hard tissue formation was categorized according to the previously established scores...

Uvod: Biokompatibilnost se tumači kao sposobnost materijala da deluje uz adekvatan odgovor domaćina u određenoj situaciji. Odgovor domaćina na strano telo zavisiće od njegove hemijske reaktivnosti, površinske strukture i topografije. Dokazano je da nanostrukturirana površina bliže podražava hijerarhijsku organizaciju koštanog tkiva u odnosu na mikrostrukturiranu, povećanjem koncentracije aktivnih biomolekula koji utiču na ćelijsku migraciju, adheziju, diferencijaciju i proliferaciju. Tokom devedesetih godina, mineralni trioksidni agregat (MTA) predstavljen je kao materijal izbora za retrogradne kavitete zbog nižeg apikalnog mikropropuštanja, vezivanja u prisustvu vlage i visoke pH vrednosti. Uprkos povoljnim osobinama, MTA pokazuje suvu konzistenciju, nisku viskoznost i dugo vremena vezivanja, što ograničava njegovu kliničku upotrebu. Cilj ove studije bio je da se sintetišu nanomaterijali na bazi veoma aktivnih kalcijum-silikata unapređenih fizičko-hemijskih svojstava i ispitaju njihova biokompatibilnost i bioaktivnost u odnosu na MTA+ (Cerkamed, Stalowa Wola- Poljska). Materijali i Metod: Postupak sol-gel metode u kombinaciji sa metodom visoko-temperaturne lančane reakcije sagorevanja primenjen je u toku sinteze ispitivanih materijala. Analiza faza pre i posle hidratacija izvedena je pomoću XRD i FTIR, dok je morfologija uzoraka proučavana SEM i EDS. pH merenja su obavljena korišćenjem pH-metra, dok je količina oslobođenih jona određivana korišćenjem ICP-OES. Biokompatibilnost svežih materijala i njihovih ekstrakata (24h, 7 i 21 dan) je ispitana primenom indirektnog testa (MTT), direktnog testa (LDH), testa proliferacije (3H-timidin) i direktnom metodom (Neutralno crvena). Interakcija direktno primenjenih ispitivanih materijala sa pulpnim tkivom analizirana je na modelu kulture humanih zuba (15 i 30 dana). Osamnaest zamorca služilo je za intramišićnu implementaciju sterilnih polietilenskih cevčica ispunjenih ispitivanim materijalima (15, 30 i 60 dana). Za intrakoštani implantacioni test upotrebljeno je dvanaest novozelandskih belih zečeva podeljenih u dve grupe (30 i 90 dana)...