Disilicate Dental Ceramic Surface Preparation by 1070 nm Fiber Laser: Thermal and Ultrastructural Analysis

Abstract

Lithium disilicate dental ceramic bonding, realized by using different resins, is strictly dependent on micro-mechanical retention and chemical adhesion. The aim of this in vitro study was to investigate the capability of a 1070 nm fiber laser for their surface treatment. Samples were irradiated by a pulsed fiber laser at 1070 nm with different parameters (peak power of 5, 7.5 and 10 kW, repetition rate (RR) 20 kHz, speed of 10 and 50 mm/s, and total energy density from 1.3 to 27 kW/cm2) and the thermal elevation during the experiment was recorded by a fiber Bragg grating (FBG) temperature sensor. Subsequently, the surface modifications were analyzed by optical microscope, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS). With a peak power of 5 kW, RR of 20 kHz, and speed of 50 mm/s, the microscopic observation of the irradiated surface showed increased roughness with small areas of melting and carbonization. EDS analysis revealed that, with these parameters, there are no evident differences between laser-processed samples and controls. Thermal elevation during laser irradiation ranged between 5 °C and 9 °C. A 1070 nm fiber laser can be considered as a good device to increase the adhesion of lithium disilicate ceramics when optimum parameters are considered.

Applications of Laser Welding in Dentistry: A State-of-the-Art Review

“…Several methods were proposed for this purpose, the most popular being the utilization of hydrofluoric acid [ 123 ], but, unfortunately, its employment is not free from disadvantages [ 124 ]. For this reason, the utilization of the laser technology seems to be a good way to characterize the ceramic surface demonstrating, at the proper parameters, to preserve it from cracks, melting and fissure formation [ 125 ].…”

Effect of fiber laser application on titanium surface on bonding strength of resin cement

“…Diş hekimliğinin hemen her alanında kullanılmaya başlanan Er:YAG, Nd:YAG, CO2 ve Er,Cr:YSGG lazer sistemleri titanyum materyalinin yüzey pürüzlendirilmesinde de kullanılmaya başlanmıştır. 51 Bir çok çalışma, farklı güç aralıklarına sahip çeşitli lazerlerin, farklı dental materyallerin mekanik özellikleri ve bağlanma kuvvetleri üzerindeki etkisini araştırmıştır. 43,44,52 Titanyum gibi su içeriği olmayan bir materyal üzerinde uygulanan lazer ışını, yüzeyin lazer enerjisinin emmesiyle yüzey alanının eriyip oyulmasını sağlar, böylece yüzey topografisi değişir ve yüzey alanı genişler.…”

“…30,54,55 Bu avantajları fiber lazerlerin son yıllarda materyal yüzeylerinin işlenmesinde sıklıkla tercih edilmelerini sağlamıştır. 30,51,56,57 Ancak, diş hekimliğinde kullanımları ile ilgili çalışmalar sınırlıdır. Fiber lazer kullanılarak titanyum yüzeyi pürüzlendirilen bir çalışmada, bağlanma kuvveti değerleinin önemli ölçüde arttığı belirtilmiştir.…”

Fiber Lasers and Their Medical Applications

“…The thermal effect of laser irradiation is so small that could not damage or destroy the irradiated tissue. Such fiber lasers are widely used in therapy [41][42][43], diagnostics [44][45][46], cosmetics [40,42], and research [47,48]. The second group refers to the thermal response and members of this group are often called ablative fiber lasers.…”

“…However, there is no depth that benefits, such as compactness, high reliability, low cost, high beam quality, and power efficiency could pave the way for fiber lasers to compete with Er:YAG and diode lasers in terms of pulse energy. In this context, ex vivo study for 1070 nm fiber lasers, carried out on both tissues and materials, could be one of the promising results due to reduced thermal elevation in the irradiated tissues, thanks to the possibility of emission in ns pulse duration, limiting the collateral damage due to the overheating of the target [41]. Custom-developed laser system, developed by UFOLAB, Bilkent, illustrated in Figure 13, is another encouraging study, in which an in-house developed Yb-doped fiber burst-mode laser amplifier system with an adjustable in-burst repetition rate is seeded by an all-normal dispersion laser oscillator generating a mode-locked signal at a repetition rate of 108 MHz as the seed source.…”