Available online 10 November 2023

Nanosecond laser patterning is employed to produce periodical microgrooves on the surface of 3Y-TZP.

Interconnected microcracks, sub-micrometric pits and material pile-up are produced on the grooves after the laser treatment.

Hydrothermal degradation resistance of 3Y-TZP is decreased after the laser patterning.

Human mesenchymal stem cell spreading, elongation and alignment is enhanced on the 50 µm pattern.

Staphylococcus aureus adhesion is reduced on the patterns of low periodicity (30 and 50 µm).

Laser surface micropatterning of dental-grade zirconia (3Y-TZP) was explored with the objective of providing defined linear patterns capable of guiding bone-cell response.

A nanosecond (ns-) laser was employed to fabricate microgrooves on the surface of 3Y-TZP discs, yielding three different groove periodicities (i.e., 30, 50 and 100 µm). The resulting topography and surface damage were characterized by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). X-Ray diffraction (XRD) and Raman spectroscopy techniques were employed to assess the hydrothermal degradation resistance of the modified topographies. Preliminary biological studies were conducted to evaluate adhesion (6 h) of human mesenchymal stem cells (hMSC) to the patterns in terms of cell number and morphology. Finally, Staphylococcus aureus adhesion (4 h) to the microgrooves was investigated.

The surface analysis showed grooves of approximately 1.8 µm height that exhibited surface damage in the form of pile-up at the edge of the microgrooves, microcracks and cavities. Accelerated aging tests revealed a slight decrease of the hydrothermal degradation resistance after laser patterning, and the Raman mapping showed the presence of monoclinic phase heterogeneously distributed along the patterned surfaces. An increase of the hMSC area was identified on all the microgrooved surfaces, although only the 50 µm periodicity, which is closer to the cell size, significantly favored cell elongation and alignment along the grooves. A decrease in Staphylococcus aureus adhesion was observed on the investigated micropatterns.

The study suggests that linear microgrooves of 50 µm periodicity may help in promoting hMSC adhesion and alignment, while reducing bacterial cell attachment.

Zirconia

Dental implants

Laser patterning

Surface topography

Hydrothermal degradation

Osseointegration

Cell adhesion

Antibacterial

© 2023 The Authors. Published by Elsevier Inc. on behalf of The Academy of Dental Materials.