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I. M. Dmitruk et al.
when material is used in implant, especially for an enhancement of its biocompatibility. In recent years, significant advances in the manufacturing and quality of dental
and orthopedic implants have been achieved in the modern surgery. However, there
are many problems to be solved to improve the functioning of different implants.
Nevertheless, it should be noted that the majority of implants still have a limited
lifetime (up to 15 years). Different complications often occur due to an inflammation, infections, allergic reactions, corrosion, wear, fractures, and lack of osteointegration. It is recognized that the improvement of biological response of implants
depends on their surface functionality. The surface topography and chemical composition of the implant determine such properties as surface roughness and wettability,
which are essential for the formation of a solid implant–bone interface and for low
risk of infection. All these acute problems make the implant surface engineering an
extremely important area of research. Thus, the usage of nano- and microstructuring
of the implant surfaces is to be one of the promising methods for an enhancement
of implant functionality [1, 2]. Such methods as plasma spraying, sandblasting, acid
and anodic etching have been commercially successful for the implant treatment.
However, some of these methods have been distinguished by such disadvantages as
the surface contamination, the change of the structure and properties of the basic
material, etc. [2]. More advanced methods, such as photolithography, electron beam
lithography, and nanoprinted lithography, allow one to create surfaces with ordered
or random nanoscale and microscale structures without altering the chemical composition of the surface [3]. Recent achievements show that the laser treatment of the
implant surfaces provides both specific surface topography and less surface contamination compared to other methods [4]. Comparative studies of material processing
using different types of lasers have shown that femtosecond lasers have the advantages over nanosecond lasers in terms of higher accuracy of treatment, the reduction
of the area affected by heat, and the reduction of contamination of the modified area
[5].
Many scientific groups study laser-induced periodic surface structures (LIPSS)
formed on the surface of metals and alloys perspective for the dental [6, 7]. Thus,
authors of [8] studied the grooves with different periodicities and “lotus-like” structures on a titanium surface induced by femtosecond laser pulses from the point of view
of their influence on the behavior of human fibroblast and MG-63 osteoblast cells.
“Lotus-like” structures have been found to be superhydrophobic. These structures
promote osteoblast proliferation but inhibit fibroblast proliferation that is useful for
orthopedic titanium implants. Therefore, there is possible correlation between the
laser-induced hydrophobicity and cell growth, namely, the higher hydrophobicity
reduces the fibroblast proliferation. Thus, simple wetting tests on the structured
surfaces can predict cell response on laser-modified surfaces.
Authors of [9] reveal specific morphological changes of titanium surface under
the femtosecond laser treatment with different laser fluencies in vacuum. Chemical analysis of the treated Ti surface indicates the local surface cleaning under the
influence of high-intensity femtosecond radiation.
I. M. Dmitruk et al.
when material is used in implant, especially for an enhancement of its biocompatibility. In recent years, significant advances in the manufacturing and quality of dental
and orthopedic implants have been achieved in the modern surgery. However, there
are many problems to be solved to improve the functioning of different implants.
Nevertheless, it should be noted that the majority of implants still have a limited
lifetime (up to 15 years). Different complications often occur due to an inflammation, infections, allergic reactions, corrosion, wear, fractures, and lack of osteointegration. It is recognized that the improvement of biological response of implants
depends on their surface functionality. The surface topography and chemical composition of the implant determine such properties as surface roughness and wettability,
which are essential for the formation of a solid implant–bone interface and for low
risk of infection. All these acute problems make the implant surface engineering an
extremely important area of research. Thus, the usage of nano- and microstructuring
of the implant surfaces is to be one of the promising methods for an enhancement
of implant functionality [1, 2]. Such methods as plasma spraying, sandblasting, acid
and anodic etching have been commercially successful for the implant treatment.
However, some of these methods have been distinguished by such disadvantages as
the surface contamination, the change of the structure and properties of the basic
material, etc. [2]. More advanced methods, such as photolithography, electron beam
lithography, and nanoprinted lithography, allow one to create surfaces with ordered
or random nanoscale and microscale structures without altering the chemical composition of the surface [3]. Recent achievements show that the laser treatment of the
implant surfaces provides both specific surface topography and less surface contamination compared to other methods [4]. Comparative studies of material processing
using different types of lasers have shown that femtosecond lasers have the advantages over nanosecond lasers in terms of higher accuracy of treatment, the reduction
of the area affected by heat, and the reduction of contamination of the modified area
[5].
Many scientific groups study laser-induced periodic surface structures (LIPSS)
formed on the surface of metals and alloys perspective for the dental [6, 7]. Thus,
authors of [8] studied the grooves with different periodicities and “lotus-like” structures on a titanium surface induced by femtosecond laser pulses from the point of view
of their influence on the behavior of human fibroblast and MG-63 osteoblast cells.
“Lotus-like” structures have been found to be superhydrophobic. These structures
promote osteoblast proliferation but inhibit fibroblast proliferation that is useful for
orthopedic titanium implants. Therefore, there is possible correlation between the
laser-induced hydrophobicity and cell growth, namely, the higher hydrophobicity
reduces the fibroblast proliferation. Thus, simple wetting tests on the structured
surfaces can predict cell response on laser-modified surfaces.
Authors of [9] reveal specific morphological changes of titanium surface under
the femtosecond laser treatment with different laser fluencies in vacuum. Chemical analysis of the treated Ti surface indicates the local surface cleaning under the
influence of high-intensity femtosecond radiation.