Author(s):
1. Valentina Veselinović, University of Banja Luka, Medical Faculty, Republic of Srpska, Bosnia and Herzegovina
2. Nataša Trtić, Republic of Srpska, Bosnia and Herzegovina
3. Rebeka Rudolf, University of Maribor, Faculty of Mechanical Engineering, Slovenia
4. Verica Pavlić, PHI Institute of Dentistry, Banja Luka, Republic of Srpska, Bosnia and Herzegovina
5. Radmila Arbutina, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
6. Saša Marin, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina

Abstract:
Introduction: Urgent demand for high-esthetic material, which at the same time has the possibility of absorption of mastication stress, has led to the technological development of hybrid nanoceramics used in CAD / CAM technology. Aim: The aim of the study was to evaluate the effects of different surface modification of hybrid nanoceramic crowns on the quality of the cement retention and the influence of the mastication stress after one year of functions. Materials and methods: 50 hybrid nanoceramic CAD/CAM crowns (CERASMART, GC) are cemented on titanium implant abutments with self adhesive resin cement (G-CEM, LinkAce). The samples were divided into five main groups according to surface treatment (n=10): I (sandblasted with 50 microns Al2O3), II (treated with CERAMIC PRIMER II, GC), III (treated with 5% hydrofluoric acid), IV (treated with combination of 5% hydrofluoric acid and CERAMIC PRIMER II), V (control, non-treated group). The samples were storaged during 24 hours on 37°C, thermocycled and loaded under 10 000 mechanical cycles loads MCO (simulation of 12 months of function). Retention forces measured in Universal testing machine. The data was represented as mean ± standard deviation, and for statistical analysis ANOVA test was used. Results: The highest initial retention force was demonstrated in the group IV (6.99±1.18), followed by group I (6.22±1.29), group III (5,97±1,25), group II (5,86±1,17) and control group samples (4.92±1.19). A statistically significant decline in retention force was recorded in all tested groups, with the lowest decrease observed in samples treated with a combination of 5% hydrofluoric acid and CERAMIC PRIMER II (6.08 ± 1.03). Conclusion: Mechanical and chemical surface modification can strongly influenced the retentions between resin cement and hybrid nanoceramics. The results from this study are suggesting that the most efficient clinical outcome resulting by combination of 5% hidrofluoric acid and CERAMIC PRIMER II.

Key words:
hybrid nanoceramics,surface treatments,termocycling,mechanical cycle loading,cementation,cement retention

Thematic field:
SYMPOSIUM B - Biomaterials and nanomedicine

Date of abstract submission:
24.07.2017.

Conference:
Contemporary Materials 2017 - Savremeni Materijali