TY  - JOUR
AU  - Ayoub, Giuma
AU  - Ležaja-Zebić, Maja
AU  - Miletić, Vesna
AU  - Petrović, Rada
AU  - Veljović, Đorđe
AU  - Janaćković, Đorđe
PY  - 2020
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1046
AB  - The application of sintered calcium phosphate dental inserts in the central part of tooth cavities can reduce amount of embedded dental composite and polymerization shrinkage of final dental fillings. The aim of this study was to analyze comparatively physico-chemical and mechanical properties of dental inserts and shear bond strength (SBS) between three dissimilar hydroxyapatite-based dental inserts and different restorative materials, after application of different clinical protocols. Starting from two different hydroxyapatite nano powders and nanostructured stabilized zirconia (YSZ), monophasic two-step sintered dense HAp inserts (TSSHAp), biphasic single-step sintered controlled porous inserts (HAp/TCp), and single-step sintered reinforced HAp/YSZ inserts were processed and characterized. Obvious differences in the microstructure of inserts surface were visualized after etching with 37% phosphoric acid. Fracture toughness of sintered inserts was ranged between 1.01 and 1.85 MPam(1/2) (maximum value in the case of HAp/YSZ), while hardness values were in the range of 3.71-5.22 GPa (maximum value in the case of TSSHAp). Acid etching before application improved SBS between inserts and Maxcem compared to direct cement application. TSSHAp and HAP/TCp inserts showed comparable and relatively high SBS values, certainly higher compared to HAp/YSZ inserts. Slightly higher SBS values were measured in the case of TSSHAp insert group, and the highest mean SBS value of 18.51 MPa was determined between TSSHAp inserts and Filtek Z250_SBU following the "self-etch" protocol.
PB  - Wiley, Hoboken
T2  - Journal of Biomedical Materials Research Part B: Applied Biomaterials
T1  - Dissimilar sintered calcium phosphate dental inserts as dentine substitutes: Shear bond strength to restorative materials
DO  - 10.1002/jbm.b.34578
ER  - 

@article{
author = "Ayoub, Giuma and Ležaja-Zebić, Maja and Miletić, Vesna and Petrović, Rada and Veljović, Đorđe and Janaćković, Đorđe",
year = "2020",
abstract = "The application of sintered calcium phosphate dental inserts in the central part of tooth cavities can reduce amount of embedded dental composite and polymerization shrinkage of final dental fillings. The aim of this study was to analyze comparatively physico-chemical and mechanical properties of dental inserts and shear bond strength (SBS) between three dissimilar hydroxyapatite-based dental inserts and different restorative materials, after application of different clinical protocols. Starting from two different hydroxyapatite nano powders and nanostructured stabilized zirconia (YSZ), monophasic two-step sintered dense HAp inserts (TSSHAp), biphasic single-step sintered controlled porous inserts (HAp/TCp), and single-step sintered reinforced HAp/YSZ inserts were processed and characterized. Obvious differences in the microstructure of inserts surface were visualized after etching with 37% phosphoric acid. Fracture toughness of sintered inserts was ranged between 1.01 and 1.85 MPam(1/2) (maximum value in the case of HAp/YSZ), while hardness values were in the range of 3.71-5.22 GPa (maximum value in the case of TSSHAp). Acid etching before application improved SBS between inserts and Maxcem compared to direct cement application. TSSHAp and HAP/TCp inserts showed comparable and relatively high SBS values, certainly higher compared to HAp/YSZ inserts. Slightly higher SBS values were measured in the case of TSSHAp insert group, and the highest mean SBS value of 18.51 MPa was determined between TSSHAp inserts and Filtek Z250_SBU following the "self-etch" protocol.",
publisher = "Wiley, Hoboken",
journal = "Journal of Biomedical Materials Research Part B: Applied Biomaterials",
title = "Dissimilar sintered calcium phosphate dental inserts as dentine substitutes: Shear bond strength to restorative materials",
doi = "10.1002/jbm.b.34578"
}

Ayoub, G., Ležaja-Zebić, M., Miletić, V., Petrović, R., Veljović, Đ.,& Janaćković, Đ.. (2020). Dissimilar sintered calcium phosphate dental inserts as dentine substitutes: Shear bond strength to restorative materials. in Journal of Biomedical Materials Research Part B: Applied Biomaterials
Wiley, Hoboken..
https://doi.org/10.1002/jbm.b.34578

Ayoub G, Ležaja-Zebić M, Miletić V, Petrović R, Veljović Đ, Janaćković Đ. Dissimilar sintered calcium phosphate dental inserts as dentine substitutes: Shear bond strength to restorative materials. in Journal of Biomedical Materials Research Part B: Applied Biomaterials. 2020;.
doi:10.1002/jbm.b.34578 .

Ayoub, Giuma, Ležaja-Zebić, Maja, Miletić, Vesna, Petrović, Rada, Veljović, Đorđe, Janaćković, Đorđe, "Dissimilar sintered calcium phosphate dental inserts as dentine substitutes: Shear bond strength to restorative materials" in Journal of Biomedical Materials Research Part B: Applied Biomaterials (2020),
https://doi.org/10.1002/jbm.b.34578 . .

TY  - JOUR
AU  - Ayoub, Giuma
AU  - Veljović, Đorđe
AU  - Ležaja-Zebić, Maja
AU  - Miletić, Vesna
AU  - Palcevskis, Eriks
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2018
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2305
AB  - The objective of the study was to process nano-structured hydroxyapatite/yttrium-stabilized zirconia bioceramic and to investigate the possibilities of its application as dentin replacement in the form of dental inserts. The processing conditions were varied in order to optimize phase composition, microstructure, fracture toughness, hardness and shear bond strength (SBS) between the obtained composite inserts and restorative materials, following either the "total-etch" or "self-etch" clinical protocol. Composite nano-powder, obtained by mixing and homogenization of 80 wt% of stoichiometric hydroxyapatite (HAp) synthesized by modified precipitation method and 20wt% of yttrium-stabilized ZrO2 (YSZ) synthesized by plasma method, was isostatically pressed into cylinder-shaped green bodies. After dilatometric analysis, HAp/YSZ inserts were sintered in the temperature range from 1200 degrees C to 1300 degrees C. Hardness and fracture toughness of sintered inserts were ranged between 3.90 +/- 0.20 - 3.95 +/- 0.12 GPa and 1.82 +/- 0.04 - 1.88 +/- 0.03 MPam(1/2), respectively. Microstructural analysis of biphasic HAp/t-ZrO2 inserts indicated two potential fracture mechanisms for fracture toughness increasing. Sintering temperature and different clinical protocols affected SBS between processed inserts and commercial dental restorative materials. Maximum SBS values of 10.50 +/- 4.94 MPa (mean standard deviation) were reached in inserts sintered at 1300 degrees C, following the "self-etch" protocol of adhesive application. It could be concluded that resin-based composites could be strongly bonded to HAp/YSZ inserts, preferably with self-etch" adhesive application. In addition, the values of fracture toughness and hardness of the obtained inserts indicated the possibility of their usage as dentin substitutes, which could be a good prerequisite for satisfactory mechanics of restored teeth.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes
VL  - 44
IS  - 15
SP  - 18200
EP  - 18208
DO  - 10.1016/j.ceramint.2018.07.028
ER  - 

@article{
author = "Ayoub, Giuma and Veljović, Đorđe and Ležaja-Zebić, Maja and Miletić, Vesna and Palcevskis, Eriks and Petrović, Rada and Janaćković, Đorđe",
year = "2018",
abstract = "The objective of the study was to process nano-structured hydroxyapatite/yttrium-stabilized zirconia bioceramic and to investigate the possibilities of its application as dentin replacement in the form of dental inserts. The processing conditions were varied in order to optimize phase composition, microstructure, fracture toughness, hardness and shear bond strength (SBS) between the obtained composite inserts and restorative materials, following either the "total-etch" or "self-etch" clinical protocol. Composite nano-powder, obtained by mixing and homogenization of 80 wt% of stoichiometric hydroxyapatite (HAp) synthesized by modified precipitation method and 20wt% of yttrium-stabilized ZrO2 (YSZ) synthesized by plasma method, was isostatically pressed into cylinder-shaped green bodies. After dilatometric analysis, HAp/YSZ inserts were sintered in the temperature range from 1200 degrees C to 1300 degrees C. Hardness and fracture toughness of sintered inserts were ranged between 3.90 +/- 0.20 - 3.95 +/- 0.12 GPa and 1.82 +/- 0.04 - 1.88 +/- 0.03 MPam(1/2), respectively. Microstructural analysis of biphasic HAp/t-ZrO2 inserts indicated two potential fracture mechanisms for fracture toughness increasing. Sintering temperature and different clinical protocols affected SBS between processed inserts and commercial dental restorative materials. Maximum SBS values of 10.50 +/- 4.94 MPa (mean standard deviation) were reached in inserts sintered at 1300 degrees C, following the "self-etch" protocol of adhesive application. It could be concluded that resin-based composites could be strongly bonded to HAp/YSZ inserts, preferably with self-etch" adhesive application. In addition, the values of fracture toughness and hardness of the obtained inserts indicated the possibility of their usage as dentin substitutes, which could be a good prerequisite for satisfactory mechanics of restored teeth.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes",
volume = "44",
number = "15",
pages = "18200-18208",
doi = "10.1016/j.ceramint.2018.07.028"
}

Ayoub, G., Veljović, Đ., Ležaja-Zebić, M., Miletić, V., Palcevskis, E., Petrović, R.,& Janaćković, Đ.. (2018). Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes. in Ceramics International
Elsevier Sci Ltd, Oxford., 44(15), 18200-18208.
https://doi.org/10.1016/j.ceramint.2018.07.028

Ayoub G, Veljović Đ, Ležaja-Zebić M, Miletić V, Palcevskis E, Petrović R, Janaćković Đ. Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes. in Ceramics International. 2018;44(15):18200-18208.
doi:10.1016/j.ceramint.2018.07.028 .

Ayoub, Giuma, Veljović, Đorđe, Ležaja-Zebić, Maja, Miletić, Vesna, Palcevskis, Eriks, Petrović, Rada, Janaćković, Đorđe, "Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes" in Ceramics International, 44, no. 15 (2018):18200-18208,
https://doi.org/10.1016/j.ceramint.2018.07.028 . .

TY  - JOUR
AU  - Matić, Tamara
AU  - Ležaja-Zebić, Maja
AU  - Cvijović-Alagić, Ivana
AU  - Miletić, Vesna
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
AU  - Veljović, Đorđe
PY  - 2018
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2281
AB  - This study aimed to investigate the possibility of modifying model BisGMA/TEGDMA dental composite by substituting 10 wt. % of conventional glass fillers with bioactive fillers based on calcinated nanosized hydroxyapatite (HAp) and Mg-doped hydroxyapatite (Mg-HAp). HAp and Mg-HAp powders were synthesized hydrothermally. Mechanical properties: hardness by Vickers (HV) and flexural strength (Fs) were tested initially and after being stored for 28 days in simulated body fluid (SBF). The experimental composites with HAp and Mg-HAp particles showed no statistically significant difference in HV compared to the control (p>0.05) either initially or after storage. Although mean Fs values of modified composites tested initially were lower (62 MPa) than those of the control (72 MPa), after 28 days of storage in SBF Fs values were greater for modified composites (42 MPa control sample, 48 MPa HAp, and Mg-HAp samples). In vitro bioactivity of BisGMA/TEGDMA composites with HAp and Mg-HAp particles after 28 days in SBF was not detected.
PB  - Savez inženjera metalurgije Srbije, Beograd
T2  - Metallurgical & Materials Engineering
T1  - The effect of calcinated hydroxyapatite and magnesium doped hydroxyapatite as fillers on the mechanical properties of a model bisgma/tegdma dental composite initially and after aging
VL  - 24
IS  - 4
SP  - 271
EP  - 281
DO  - 10.30544/403
ER  - 

@article{
author = "Matić, Tamara and Ležaja-Zebić, Maja and Cvijović-Alagić, Ivana and Miletić, Vesna and Petrović, Rada and Janaćković, Đorđe and Veljović, Đorđe",
year = "2018",
abstract = "This study aimed to investigate the possibility of modifying model BisGMA/TEGDMA dental composite by substituting 10 wt. % of conventional glass fillers with bioactive fillers based on calcinated nanosized hydroxyapatite (HAp) and Mg-doped hydroxyapatite (Mg-HAp). HAp and Mg-HAp powders were synthesized hydrothermally. Mechanical properties: hardness by Vickers (HV) and flexural strength (Fs) were tested initially and after being stored for 28 days in simulated body fluid (SBF). The experimental composites with HAp and Mg-HAp particles showed no statistically significant difference in HV compared to the control (p>0.05) either initially or after storage. Although mean Fs values of modified composites tested initially were lower (62 MPa) than those of the control (72 MPa), after 28 days of storage in SBF Fs values were greater for modified composites (42 MPa control sample, 48 MPa HAp, and Mg-HAp samples). In vitro bioactivity of BisGMA/TEGDMA composites with HAp and Mg-HAp particles after 28 days in SBF was not detected.",
publisher = "Savez inženjera metalurgije Srbije, Beograd",
journal = "Metallurgical & Materials Engineering",
title = "The effect of calcinated hydroxyapatite and magnesium doped hydroxyapatite as fillers on the mechanical properties of a model bisgma/tegdma dental composite initially and after aging",
volume = "24",
number = "4",
pages = "271-281",
doi = "10.30544/403"
}

Matić, T., Ležaja-Zebić, M., Cvijović-Alagić, I., Miletić, V., Petrović, R., Janaćković, Đ.,& Veljović, Đ.. (2018). The effect of calcinated hydroxyapatite and magnesium doped hydroxyapatite as fillers on the mechanical properties of a model bisgma/tegdma dental composite initially and after aging. in Metallurgical & Materials Engineering
Savez inženjera metalurgije Srbije, Beograd., 24(4), 271-281.
https://doi.org/10.30544/403

Matić T, Ležaja-Zebić M, Cvijović-Alagić I, Miletić V, Petrović R, Janaćković Đ, Veljović Đ. The effect of calcinated hydroxyapatite and magnesium doped hydroxyapatite as fillers on the mechanical properties of a model bisgma/tegdma dental composite initially and after aging. in Metallurgical & Materials Engineering. 2018;24(4):271-281.
doi:10.30544/403 .

Matić, Tamara, Ležaja-Zebić, Maja, Cvijović-Alagić, Ivana, Miletić, Vesna, Petrović, Rada, Janaćković, Đorđe, Veljović, Đorđe, "The effect of calcinated hydroxyapatite and magnesium doped hydroxyapatite as fillers on the mechanical properties of a model bisgma/tegdma dental composite initially and after aging" in Metallurgical & Materials Engineering, 24, no. 4 (2018):271-281,
https://doi.org/10.30544/403 . .

TY  - JOUR
AU  - Jokić, Bojan
AU  - Stamenković, Ivan
AU  - Zrilić, Milorad
AU  - Obradović-Đuričić, Kosovka
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2012
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1757
AB  - In this study, spherical particles of hydroxyapatite (HA) and alpha-tricalcium phosphate (alpha-Ca-3(PO4)(2): alpha-TCP) doped with different amounts of silicon were used for the preparation of scaffolds. The scaffolds were obtained by a replica foam method using particles of narrow size distribution pre-annealed at 1150 degrees C with different alpha-TCP and HA contents in order to investigate the effect of composition on their morphological and mechanical properties. Morphology, size, and distribution of the particles were characterized using scanning electron microscopy and particle size analyzer. The obtained alpha-TCP-HA scaffolds had compressive strengths up to 5.7 MPa with a uniform and interconnected porous structure. X-ray diffraction analysis used to determine the crystal structure of the scaffolds confirmed that the alpha-TCP-HA content could be controlled by the amount of silicon ions.
PB  - Elsevier Science Bv, Amsterdam
T2  - Materials Letters
T1  - Silicon-doped biphasic alpha-calcium-phosphate/hydroxyapatite scaffolds obtained by a replica foam method using uniform pre-annealed spherical particles
VL  - 74
SP  - 155
EP  - 158
DO  - 10.1016/j.matlet.2012.01.081
ER  - 

@article{
author = "Jokić, Bojan and Stamenković, Ivan and Zrilić, Milorad and Obradović-Đuričić, Kosovka and Petrović, Rada and Janaćković, Đorđe",
year = "2012",
abstract = "In this study, spherical particles of hydroxyapatite (HA) and alpha-tricalcium phosphate (alpha-Ca-3(PO4)(2): alpha-TCP) doped with different amounts of silicon were used for the preparation of scaffolds. The scaffolds were obtained by a replica foam method using particles of narrow size distribution pre-annealed at 1150 degrees C with different alpha-TCP and HA contents in order to investigate the effect of composition on their morphological and mechanical properties. Morphology, size, and distribution of the particles were characterized using scanning electron microscopy and particle size analyzer. The obtained alpha-TCP-HA scaffolds had compressive strengths up to 5.7 MPa with a uniform and interconnected porous structure. X-ray diffraction analysis used to determine the crystal structure of the scaffolds confirmed that the alpha-TCP-HA content could be controlled by the amount of silicon ions.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Materials Letters",
title = "Silicon-doped biphasic alpha-calcium-phosphate/hydroxyapatite scaffolds obtained by a replica foam method using uniform pre-annealed spherical particles",
volume = "74",
pages = "155-158",
doi = "10.1016/j.matlet.2012.01.081"
}

Jokić, B., Stamenković, I., Zrilić, M., Obradović-Đuričić, K., Petrović, R.,& Janaćković, Đ.. (2012). Silicon-doped biphasic alpha-calcium-phosphate/hydroxyapatite scaffolds obtained by a replica foam method using uniform pre-annealed spherical particles. in Materials Letters
Elsevier Science Bv, Amsterdam., 74, 155-158.
https://doi.org/10.1016/j.matlet.2012.01.081

Jokić B, Stamenković I, Zrilić M, Obradović-Đuričić K, Petrović R, Janaćković Đ. Silicon-doped biphasic alpha-calcium-phosphate/hydroxyapatite scaffolds obtained by a replica foam method using uniform pre-annealed spherical particles. in Materials Letters. 2012;74:155-158.
doi:10.1016/j.matlet.2012.01.081 .

Jokić, Bojan, Stamenković, Ivan, Zrilić, Milorad, Obradović-Đuričić, Kosovka, Petrović, Rada, Janaćković, Đorđe, "Silicon-doped biphasic alpha-calcium-phosphate/hydroxyapatite scaffolds obtained by a replica foam method using uniform pre-annealed spherical particles" in Materials Letters, 74 (2012):155-158,
https://doi.org/10.1016/j.matlet.2012.01.081 . .