Fabrication of micropores on titanium implants using femtosecond laser technology: Perpendicular attachment of connective tissues as a pilot study

Abstract

Peri-implantitis leads to the destruction of hard and soft tissues, ultimately leading to a loss of the dental implant supporting structures. Current treatments can limit disease progression; however, true regeneration, characterised by perpendicularly oriented fibre attachment to the implant surface, remains challenging. Herein, we aim to enhance the quality of the peri-implant soft-tissue integration via the fabrication of vertically aligned micropores on Ti alloy (Ti6Al4V, Ti64) implant surfaces. The micropores are created via the subtraction fabrication method known as femtosecond (FS) laser micromachining. This study achieved highly accurate micropore texturing on Ti64 substrates with optimised parameters of 2 × 104 pulses per spot, 100 kHz and 220 FS laser pulse duration. The surface characteristics of human gingival fibroblasts (hGF), such as morphology and roughness, were investigated by scanning electron microscope and optical profiler techniques. The FS micromachining approach resulted in outstanding topographical properties of highly systematic vertically aligned micropores (7 and 15 µm) on the Ti64 surfaces. The response of hGF cells with the micro-patterned surfaces was also investigated by confocal laser scanning microscopy and scanning electron microscopy after ten days in vitro culture. The hGF cells migrated deep (>10 µm) and attached along the internal walls of the vertically orientated micropores demonstrating excellent integration. This pilot study provides a possible new concept for a clinically valuable strategy to enhance Ti surface properties with precise micropores for promoting superior peri-implant subgingival soft tissue integration.