242
I. M. Dmitruk et al.
fulfilled. The topography features of the obtained laser-induced periodic/disordered
surfaces are examined from the point of view of efficiency of cell culture viability
on such surfaces.
2 Experimental Details
For the laser treatment of specimen surfaces, the technological capabilities of the
Femtosecond Laser Centre for Collective Use of NAS of Ukraine have been used,
namely, a femtosecond laser composed of a Ti:sapphire laser set “Mira Optima
900-F” and regenerative amplifier “Legend HE” by “Coherent” (USA). The main
parameters of a femtosecond laser are a pulse duration 150 fs–3 ps (with chirp), a
repetition rate of 1 kHz, an average power up to 1 W, a pulse energy up to 1 mJ, and
the main wavelength of the radiation 800 nm. The generation of the second (400 nm)
and third (266 nm) harmonics of the femtosecond laser was also available due to
the usage of corresponding optical borate crystals. For the generation of the third
harmonic, the plate compensator of group velocity (calcite) and plate (λ/2) 800 which
rotated the polarization plane of the radiation of the fundamental harmonic (800 nm)
were put after the crystal generator of the second harmonic in the experimental setup.
The laser beam focused on the surface of the irradiated sample with a lens. The power
density of the laser radiation could be varied by adjusting the distance of the sample
from the lens focus. To measure the average power (up to 10 W), the laser power
meter “Field Master GS” with the detector head “LM-10” (“Coherent,” USA) was
used. A computer-controlled three-coordinate platform (Standa, Lithuania) has been
used for precision moving-scanning of the samples. All laser treatment procedures
have been performed in air.
The morphology of the studied specimen surfaces has been analyzed by means
of scanning electron microscopy (SEM) using Tescan VEGA 3 microscope.
The samples in our study are of three types related to dental implants, namely,
metal, two-component alloy, and ceramics. The samples of Zr and Ti–Zr alloys are in
the form of ground or polished washers. Some of the specimen surfaces were modified
by the method of sandblasting with large grit with subsequent electroetching—SLE
surface (Sand-blasted, Large grit, and Electro-etched). Sintered yttrium-stabilized
tetragonal zirconia polycrystalline (Y-TZP) samples have been also examined.
For the biocompatibility study, the samples were sterilized in autoclave (121 °C
during 1 h) and placed in 24-well plates. Each well was filled up with 20% of Fetal
Bovine Serum (FBS; Invitrogen) in Dulbecco’s Modified Eagle Medium (DMEM;
Invitrogen, cat. no. 11960) overnight. This procedure was performed to mimic protein
adhesion to the implant surface after implantation. Next day media removed from well
and 2 ml of DMEM supplemented with 10% Fetal Bovine Serum (FBS; Invitrogen),
2 mM l-glutamine (Invitrogen, cat. no. 25030), 0.1 mM 2-mercaptoethanol (Sigma,
cat. no. M7522), 50 units/mL penicillin, and 50 g/mL streptomycin (Invitrogen, cat.
no. 15070) was added to each well. 10 5 Rats Osteoblast and Dermal Fibroblast (in
separate well) were seeded on the top surface of each sample and incubated at 37 °C
I. M. Dmitruk et al.
fulfilled. The topography features of the obtained laser-induced periodic/disordered
surfaces are examined from the point of view of efficiency of cell culture viability
on such surfaces.
2 Experimental Details
For the laser treatment of specimen surfaces, the technological capabilities of the
Femtosecond Laser Centre for Collective Use of NAS of Ukraine have been used,
namely, a femtosecond laser composed of a Ti:sapphire laser set “Mira Optima
900-F” and regenerative amplifier “Legend HE” by “Coherent” (USA). The main
parameters of a femtosecond laser are a pulse duration 150 fs–3 ps (with chirp), a
repetition rate of 1 kHz, an average power up to 1 W, a pulse energy up to 1 mJ, and
the main wavelength of the radiation 800 nm. The generation of the second (400 nm)
and third (266 nm) harmonics of the femtosecond laser was also available due to
the usage of corresponding optical borate crystals. For the generation of the third
harmonic, the plate compensator of group velocity (calcite) and plate (λ/2) 800 which
rotated the polarization plane of the radiation of the fundamental harmonic (800 nm)
were put after the crystal generator of the second harmonic in the experimental setup.
The laser beam focused on the surface of the irradiated sample with a lens. The power
density of the laser radiation could be varied by adjusting the distance of the sample
from the lens focus. To measure the average power (up to 10 W), the laser power
meter “Field Master GS” with the detector head “LM-10” (“Coherent,” USA) was
used. A computer-controlled three-coordinate platform (Standa, Lithuania) has been
used for precision moving-scanning of the samples. All laser treatment procedures
have been performed in air.
The morphology of the studied specimen surfaces has been analyzed by means
of scanning electron microscopy (SEM) using Tescan VEGA 3 microscope.
The samples in our study are of three types related to dental implants, namely,
metal, two-component alloy, and ceramics. The samples of Zr and Ti–Zr alloys are in
the form of ground or polished washers. Some of the specimen surfaces were modified
by the method of sandblasting with large grit with subsequent electroetching—SLE
surface (Sand-blasted, Large grit, and Electro-etched). Sintered yttrium-stabilized
tetragonal zirconia polycrystalline (Y-TZP) samples have been also examined.
For the biocompatibility study, the samples were sterilized in autoclave (121 °C
during 1 h) and placed in 24-well plates. Each well was filled up with 20% of Fetal
Bovine Serum (FBS; Invitrogen) in Dulbecco’s Modified Eagle Medium (DMEM;
Invitrogen, cat. no. 11960) overnight. This procedure was performed to mimic protein
adhesion to the implant surface after implantation. Next day media removed from well
and 2 ml of DMEM supplemented with 10% Fetal Bovine Serum (FBS; Invitrogen),
2 mM l-glutamine (Invitrogen, cat. no. 25030), 0.1 mM 2-mercaptoethanol (Sigma,
cat. no. M7522), 50 units/mL penicillin, and 50 g/mL streptomycin (Invitrogen, cat.
no. 15070) was added to each well. 10 5 Rats Osteoblast and Dermal Fibroblast (in
separate well) were seeded on the top surface of each sample and incubated at 37 °C