Effects of Lasers and Their Delivery Characteristics on Machined and Micro-Roughened Titanium Dental Implant Surfaces

Abstract

The aim of the study was to investigate the effects of neodymium: yttrium aluminium garnet (Nd:YAG) (1064 nm) and erbium: yttrium aluminium garnet (Er:YAG) (2940 nm) laser energy on titanium when delivered with conventional optics (focusing handpieces or plain ended optical fibres) or with a conical tip. Machined and micro-roughened implant discs were subjected to laser irradiation under a variety of energy settings either dry (without water) or wet (with water). Samples were scanned using a 3D non-contact laser profilometer and analysed for surface roughness, volume of peaks and the maximum diameter of the ablated area. Conical tip designs when used with both lasers showed no surface effect at any power setting on both machined and micro-roughened implant surfaces, regardless of the irrigation condition. When used with conventional delivery systems, laser effects on titanium were dose related, and were more profound with the Nd:YAG than with the Er:YAG laser. High laser pulse energies caused surface fusion which reduced the roughness of micro-roughened titanium surfaces. Likewise, repeated pulses and higher power densities also caused greater surface modifications. The presence of water reduced the influence of laser irradiation on titanium. It may be concluded that conical fibres can reduce unwanted surface modification, and this may be relevant to clinical protocols for debridement or disinfection of titanium dental implants.

Effects of lasers on titanium dental implant surfaces: a narrative review

“…When multiple Nd:YAG laser pulses are delivered onto the same site, extensive changes to the titanium surface will result. Fenelon et al in 2020 showed this effect for both machined and rough surface titanium samples irradiated with plain fibre tips and documented severe surface modifications, which increased in severity with increasing pulse energy [63]. The nature of such effects can be documented using measurements of surface roughness, as well as 3D imagery (Fig.…”

“…600 mJ/pulse) could influence machined titanium surfaces, causing roughening of the surface, with a complex pattern of peaks and troughs. Rough implant surfaces with micro and nano-scale features may be more prone to the absorption of laser energy, putting them more at risk of unintended modification of the surface at lower power settings [63]. On many occasions, it is impossible to completely remove the biofilm without causing surface alterations [64].…”

“…Using the same panel setting, changing the handpiece or tip will alter the attenuation within the delivery system as well as the dispersion of energy from the tip. In practical terms, this means that thresholds need to be considered for different laser delivery systems as well as for different laser wavelengths [63].…”

“…A possible explanation for the more pronounced surface effect seen on a roughened (etched grit-blasted) surface than a machined surface discs lies in the greater surface area of the former. Fenelon et al in 2020 used 3D profilometry to show the dense pattern of fine peaks and troughs on a roughened surface results in a greatly increased surface area [63]. This rough surface reflects less but absorbs more laser energy than a machined surface (Fig.…”

Anesthetic-, irrigation- and pain-free dentistry? The case for a femtosecond laser enabled intraoral robotic device

“…Such pulse durations are between one million and one billion times longer than those in the picosecond and femtosecond range used by USP lasers (40). Their effect on dental hard tissues is thermo-mechanical in nature, and they have limited ability to ablate metals and ceramics (42).…”