Ablation Precision and Thermal Effects of a Picosecond Infrared Laser (PIRL) on Roots of Human Teeth: A Pilot Study Ex Vivo

Abstract

Background/Aim: Picosecond infrared laser (PIRL) was investigated regarding its possible therapeutic application in cutting dental roots. Materials and Methods: Extracted human teeth were processed in the root area by laser ablations followed by histological evaluation. Dentin adjacent to the cutting surface was evaluated morphometrically. Results: PIRL produced clearly defined cutting boundaries in dental roots. At the bottom of the cavity, the ablation surface became slightly concave. Heat development in this scantly hydrated tissue was considerable. We attributed the excess heating effects to heat accumulation due to multiple pulse overlap across a limited scan range imposed by tooth geometries. Conclusion: Defined areas of the tooth root may be treated using the PIRL. For clinical translation, it would be necessary to improve beam delivery to facilitate beam steering for the intended oral application (e.g. by using a fiber) and identify optimal repetition rates/scan speeds combined with cooling techniques to minimize accumulated heat within ablation cavities.

Metabolic Lipids in Melanoma Enable Rapid Determination of Actionable BRAF-V600E Mutation with Picosecond Infrared Laser Mass Spectrometry in 10 s

“…One such ambient MS method utilizes the efficient coupling, on the picosecond time scale, between ablation and vibrational hydroxyl (−OH) stretch modes in water molecules (abundant in biological tissues) . Using pulses of mid-infrared laser energy with durations on the picosecond scale, a highly efficient desorption source is created − that minimally damages the tissue outside the ablation zone, ,− requiring less than 1 mm 3 of tissue for a 10 s determination of various tissue pathologies through supervised multivariate modeling and comparisons with previously established, pathology-validated molecular libraries. ,, The method entitled picosecond infrared laser mass spectrometry (PIRL-MS) has been shown to recapitulate several morphometrically (as well as molecularly) distinct types and subtypes of cancers based on metabolic lipids statistically correlated to various pathologies. − ,, PIRL-MS analysis, however, has not been examined for its potential utility in elucidating a specific mutation status from its correlated downstream metabolites. In this work, a set of metabolite ions associated with an oncogenic BRAF-V600E driver mutation were identified with untargeted PIRL-MS in a cell line model.…”

Picosecond Infrared Laser Mass Spectrometry Identifies a Metabolite Array for 10 s Diagnosis of Select Skin Cancer Types: A Proof-of-Concept Feasibility Study

“…Much like reports of utility of infrared lasers with larger pulse durations in MS, , a picosecond infrared laser sampling probe (ambient analysis) combined with MS (PIRL-MS) has recently shown utility in 10 s diagnosis of medulloblastoma subgroups with >95% sensitivity and specificity, and no signal carry over between measurements . This aerosolization is driven primarily through photomechanical mechanisms with minimal thermal damage − and produces scar-free incisions that heal rapidly, so that it is well suited to skin cancer investigations in situ where cosmesis is important. In addition, as PIRL-MS requires only ∼1 mm 3 of tissue, downstream gross histopathologic evaluations of the laser sampled tissue is not drastically compromised .…”

A Novel Method for Adjusting the Taper and Adaption of Automatic Tooth Preparations with a High-Power Femtosecond Laser

“…However, current research on the use of lasers in dentistry has mainly focused on the microscopic morphology, thermal effect, and ablation efficiency of lasers on the dental hard tissues [ 14 , 28 , 29 , 30 , 31 ]. There have been few studies on the accuracy of robotically controlled femtosecond laser ablation in tooth preparation.…”