Evaluation of soft‐tissue response around laser microgrooved titanium percutaneous devices

Abstract

Percutaneous devices are prone to epidermal downgrowth and sinus tract formation, which can serve as a nidus for bacterial colonization and increase the risk of periprosthetic infection. A laser microgrooved topography has been shown to limit gingival epidermal downgrowth around dental implants. However, the efficacy of this laser microgrooved topography to limit epidermal downgrowth around nongingival percutaneous devices is yet to be investigated. In this study, devices with a porouscoated subdermal component and a percutaneous post were designed and manufactured. The proximal 2 mm section of the percutaneous post were left smooth, or were textured with either a porous coating, or with the laser microgrooved topography. The smooth and porous topographies served as controls. The devices were tested in a hairless guinea pig back model, where 18 animals were randomly assigned into three groups, with each group receiving one implant type (n = 6/group). Four weeks postimplantation, the devices with surrounding soft-tissues were harvested and processed for histological analyses. Results indicated that the laser microgrooved topography failed to prevent epidermal downgrowth (23 ± 4%) around percutaneous posts in this model. Furthermore, no significant differences (p = 0.70) in epidermal downgrowth were present between the three topographies, with all the groups exhibiting similar measures of downgrowth. Overall, these findings suggest that the laser microgrooved topography may not halt downgrowth around percutaneous devices for dermal applications.

Soft and Hard Tissue Integration around Percutaneous Bone-Anchored Titanium Prostheses: Toward Achieving Holistic Biointegration

“…113 Similarly, laser microgrooved percutaneous devices presented reduced gingival epidermal downgrowth, but no significant reduction in epidermal downgrowth was noted in extraoral percutaneous abutments. 97 Notwithstanding, acid treatment (10−20 min) of Ti increased its surface roughness to Sa = 0.2−0.5 μm that conferred instant adhesive properties to Ti manifested as an increase in shear adhesion strength of 60 kPa, when tested using murine dermal tissues. 114 Along similar lines, aligned titania nanopores (TNPs of 50−75 nm diameter) generated by electrochemical anodization of Ti increased filopodial extensions and stress fibers by gingival fibroblasts (GFs), suggesting stronger, greater cell spreading and adhesion.…”

“…While extremely rough abutments can encourage microbial colonization, microrough nanotopographic (Sa ∼ 134 ± 30 nm) abutment surfaces created by anodization elicited stronger adhesion of gingival fibroblasts and wound healing characteristics . Similarly, laser microgrooved percutaneous devices presented reduced gingival epidermal downgrowth, but no significant reduction in epidermal downgrowth was noted in extraoral percutaneous abutments . Notwithstanding, acid treatment (10–20 min) of Ti increased its surface roughness to Sa = 0.2–0.5 μm that conferred instant adhesive properties to Ti manifested as an increase in shear adhesion strength of 60 kPa, when tested using murine dermal tissues .…”

“…Peri-implant soft tissue attachment is further complicated by the aggressive foreign body response elicited by the skin against transcutaneous metallic abutments, which is in stark contrast to Ti osseointegration or acceptance of Ti implants by the bone tissue. Such an innate immune response from the skin to foreign metallic prostheses is manifested as epithelial downgrowth, a skin-related phenomenon wherein the epidermal keratinocytes migrate away from the implant surface creating invaginations/moist pockets that can be colonized by bacterial and fungal pathogens. , Furthermore, the epidermal keratinocytes adhere weakly to metallic abutment surfaces through weaker/lesser cell-ECM attachment structures, namely, hemidesmosomes (HDs), internal basal lamina (IBL), and focal adhesions compared to natural/biological percutaneous structures like teeth and nails . Therefore, peri-implant epithelium (PIE) and underlying connective tissue around metallic prosthesis is weak and can be easily breached.…”

Effects of Electrolyte on Laser-Induced Periodic Surface Structures with Picosecond Laser Pulses

“…Micro/Nanostructures can alter tribology [ 1 , 2 ], wettability [ 3 , 4 ], optical properties [ 5 , 6 ] and bioaffinity [ 7 , 8 ] on the material surface. The short-pulsed laser (SPL) is an appropriate method to fabricate nanostructures, called laser-induced periodic surface structures (LIPSSs), inducing a reduction of friction [ 9 , 10 ], water repellency and hydrophilicity [ 11 , 12 , 13 ], anti-reflection [ 14 , 15 ] and improvement of biocompatibility [ 16 , 17 ].…”