Safety and Efficacy of the Erbium Laser in Debonding Dental Accessories: A Narrative Review.

Objective: This article aims to review the safety and efficacy of the Er:YAG laser in debonding dental accessories. Methods: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles published between 2010 and 2022 on the removal of dental accessories using erbium laser were searched. The selected articles were then classified according to the accessories used: adhesives, brackets, restorations, or implant crowns. Enamel surface roughness, shear bond strength, adhesive remnant index, duration time (t), pulp chamber temperature (T), morphology (M), and other variables were then noted. Results: The dental accessories and adhesives used were described along with the laser parameters used, such as frequency, pulse width, irradiation time, scanning mode, water-air cooling, and other variables. Conclusions: Laser removal using Er:YAG laser of dental accessories such as brackets, crowns, and veneers is fundamentally safe, time-saving, and does not cause damage to the enamel nor the underlying dentin. However, there was no distinct advantage with laser removal seen, such as those residual adhesives of brackets on the tooth surface and temporary adhesives of restorations.

Effect of nanosecond- and microsecond-pulse Er,Cr:YSGG laser ablation on dentin shear bond strength of universal adhesives.

OBJECTIVE: The study aimed to evaluate the bond strength of universal adhesives to dentin after Er,Cr:YSGG laser irradiation with nanosecond-domain and microsecond-domain pulses. METHODS: Eighty extracted caries-free, sound human molars were divided into eight groups. The enamel was removed until the dentin occlusal flat dentin surface was exposed. Etch-and-rinse followed by adhesive was applied to group 1, and a self-etch adhesive was applied to group 2. Er,Cr:YSGG laser (3 mJ, 100 Hz, 100 ns), (3 mJ, 100 Hz, 150 µs), and (20 mJ, 100 Hz, 150 µs) were applied to groups 3-4, 5-6, and 7-8, respectively. The laser preparation was followed by self-etch adhesives or adhesives treatment. When the composite resin had been built up on the samples, the shear bond strength was tested, and the data were statistically analyzed using analysis of variance (ANOVA). RESULTS: Groups prepared with nanosecond-pulse laser showed significantly higher bond strength values than the microsecond-pulse laser groups and self-etch mode group, and the SEM photographs also showed more dentinal tubules and no damage in the ablation area. The shear bond strength of long pulse laser ablated was comparable to that of self-etching system when it was combined with a self-etch adhesive at low energy, but higher energy laser degraded shear bond strength. CONCLUSIONS: The pulse width of Er,Cr:YSGG laser affects the bond strength, nanosecond pulses of laser irradiation without water cooling can enhance bond strength, but microsecond pulses of laser cannot enhance bond strength.

Effects of Dentin Ablation by a Q-Switching Er:YSGG Laser with a High Pulse Repetition Rate.

Objective: The aim of the study was to evaluate the characteristics of dentin ablation with a high pulse repetition rate Q-switching 2.79 µm laser. Materials and methods: Dentin was ablated using a homemade Q-switching Er:YSGG laser with a high pulse repetition rate. Er:YSGG radiation was applied with a pulse energy of 1 or 10 mJ for 100 or 3 Hz pulse repetition rate, respectively. A scanning electron microscope (SEM) was used to observe the microstructures of dentin samples after ablation. Teeth were irradiated in vitro with a 100 Hz pulse repetition rate under two different modes: free running and Q-switching. A thermocouple was applied to measure the temperature in the pulp cavity during ablation. Results: A 100 or 3 Hz Q-switching laser was used to irradiate dentin for 30 and 100 sec, respectively. There was no significant difference in ablation mass loss between the two conditions. The SEM photographs showed more dentinal tubules and no damage in the ablation area when using the 100 Hz Q-switching laser. The temperature of the pulp cavity was maintained below 41°C when using a Q-switching laser. Conclusions: The Q-switching Er:YSGG laser with a high pulse repetition rate exhibited greater ablation efficiency and better morphology than the low pulse repetition rate Q-switching laser. The experimental results also demonstrate the significant advantage of the Q-switching laser over free-running lasers for protecting dental pulp tissue. The Q-switching Er:YSGG laser with a high pulse repetition rate is expected to become an efficient new dental tool.