Nd:YAG laser has shown some potential to be used in dental practice replacing the conventional method. In particular, it can be used to modify the tooth surface by the ablation process. The laser provides an ability to accurately deliver a significant amount of energy into a confined region. Thus, alteration of the sample surface and composition may occur during the process. Additionally, the use of a laser in ablation procedure is also associated with heat generation and potential thermal injury that may be experienced by a patient. The wet condition of the samples is expected to reduce the thermal effect. In this paper, the changes of enamel surface and elemental composition following laser irradiation of Nd:YAG laser are discussed. The teeth samples were irradiated at 1.5 Hz of pulse rate, 100 ms of pulse width, and range of fluences of 80-120 J/cm 2. Field Emission Scanning Microscopy (FESEM) and Energy Dispersive X-ray (EDX) were used to analyze the morphology and composition of the teeth samples. Samples were compared before and after laser irradiation. The percentages of carbon increased after laser irradiation, while oxygen decreased for most of the samples. The morphologies of the samples were varied with a more pronounced effect on the sample surface at higher fluence. In addition, the effect of wet sample condition is also investigated and discussed. It is demonstrated that the ablation in wet condition produced less damage to the enamel surface compared to dry sample. However, no remarkable difference between the elemental composition of wet and dry samples.

Ablation using Nd:YAG laser has potential in resulting a rough effect on tooth surfaces. The objective of this study is to perform a comparative evaluation of the roughness structure of enamel using the Cynosure Cynergy Nd:YAG laser and 37% phosphoric acid. The results obtained for laser-etched with a pulse width of 300ms show roughed and porous surface with greater depth. Both show remarkable graininess on the surface and fewer indentations. Comparison of the elemental compositions demonstrated that calcium has higher composition when exposed to laser-etch compared to acid-etch. The atomic percentages of calcium in sample A for acid-etched and laser-etched are 5.08 and 9.61, respectively. While acid-etched and laser-etched for sample B are 3.98 and 12.84, respectively. Other elements are not profoundly affected by the technique used in this study. However, carbon and oxygen show inconsistent results for both of the samples. Thus, Nd:YAG laser provides significant effects on the tooth surface but does not primarily modify the element compositions of the tooth. Therefore, Nd:YAG laser can potentially be implemented for etching procedure as a replacement of acid etching technique.

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Nd:YAG laser with a wavelength of 1064 nm has been used for various applications in dentistry, including for soft tissue and hard tissue applications. This study aimed to investigate the changes in morphological structures and elemental composition of enamel surface after composite removal using energy variations of Nd:YAG laser. 12 healthy human premolar teeth were cut into half, and Blūgloo adhesives were applied to the tooth surface. The samples were subjected to Nd:YAG laser irradiations with three different energy parameters, 510 mJ, 540 mJ, and 580 mJ. The changes in enamel surface morphology and composition of elements were analyzed using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-Ray (EDX). Surface morphology indicates that 540 mJ can potentially be used for composite adhesives removal. For the elemental composition, carbon, phosphorus, and calcium were statistically significant between samples without composite, after bracket debonding, and after laser irradiation. Several morphological changes may occur on the enamel surface after samples were irradiated with a laser. Energy parameter of the laser plays a vital role towards the desired surface. In this study, 540 mJ is seen to be potential for material removal process on the enamel surface.

The effect of Er,Cr:YSGG laser for ablation of commercialized adhesive dental materials were studied using 12 sets of tooth samples. The surface morphology and composition of the tooth samples was observed before and after irradiation using FESEM and EDX. Time dependency of exposure is observed in the tooth sample. Adhesive material Grēngloo produced better ablation on long exposure compared to adhesive material Blūgloo. The ablation effect was also compared between presence and absence of water. The enamel surface produced is highly dependent on the technique used to ablate the adhesive material. Without water, enamel surface appeared roughed and depth of crater was also created. In particular, both materials produce different quality of ablation and reacted differently under different laser parameter and setting.