# SEM Studies Assessing the Efficacy of Laser Treatment for Primary Teetis: A Systematic Review
Clinical crowns of primary teeth are characterized by reduced height, and any potential cavities tend to present with wider and shallower dimensions [8]. Factors conducive to the accelerated onset of caries in primary teeth encompass attributes such as barrel-shaped crowns, expansive and planar contact surfaces of molars, and diminished mineralization of hard dental tissues [9]. Scanning electron microscopy (SEM) has emerged as an indispensable tool across diverse research disciplines, furnishing microscopic insights into the surface or near-surface characteristics of specimens [10]. Its application extends to the meticulous assessment of cavity preparation, facilitating the elucidation of the state of the smear layer and dentinal tubules [2]. Moreover, within the scientific literature, SEM images are employed for discerning the presence or absence of bacterial deposits [11]. The analytical potential of SEM proves instrumental in identifying areas of dentin resorption and the colonization of microorganisms. Notably, this method was judiciously applied to scrutinize root canals and furcation areas, specifically in a study addressing the complexities surrounding pulpectomy failure in primary teeth [12]. Erbium-doped yttrium aluminium garnet (Er:YAG) laser irradiation is posited as a potentially advantageous approach for caries removal or cavity preparation in primary teeth, primarily due to its purported minimal impact on pulp and surrounding tissues [13]. Furthermore, the Er:YAG laser demonstrates effectiveness in reducing microbial pathogens [14]. A comprehensive study comparing various caries removal methods [2] found no statistically significant differences in mineral densities at the cavity floors. These methods encompassed mechanical rotary and non-rotating systems, chemo-mechanical systems, and the Er:YAG laser. Notably, the authors underscored that although the orifices of the tubules remain unopened after laser treatment, the exposure of markedly rough surfaces may influence the bond strength of the filling [2]. The strategic use of carbon dioxide, argon, and neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers in clinical practice emerges as an effective approach for caries prevention. For instance, the application of an erbium, chromium: yttrium-scandium-gallium-garnet (ErCr:YSGG) laser without water cooling led to increased calcium and phosphorus contents, enhancing enamel resistance to demineralization. However, the sustained preventive efficacy of this method awaits long-term substantiation, with the recommendation of acidulated phosphate fluoride gel to complement this form of prevention [15]. The lasers commonly utilized for caries treatment or prevention are depicted in Figure 1.  
Figure 1: Lasers used for the preparation or conditioning of dental tissues. Dental caries is a pervasive issue, especially among children with primary dentition, and novel methods for its management are continuously under development. Known properties of lasers and effects of their use on dental tissues prompt speculation that lasers could be a suitable alternative to traditional caries treatment in deciduous teeth. However, the topic needs to be summarized and results from various studies compared to draw specific conclusions regarding whether lasers are indeed suitable treatment for tissues of primary dentition. The aim of this study is to systematically review and consolidate existing knowledge in the scientific literature regarding the use of SEM imaging to assess the efficacy of laser treatment for primary teeth. The authors intend to assess the alterations in the surfaces of primary teeth following laser treatment using SEM. This study sought to evaluate the null hypothesis suggesting that there is no discernible difference in the surface alterations of primary teeth when utilizing different laser systems as observed through Scanning Electron Microscopy (SEM) imaging. Given the absence of a systematic review on this specific topic in the searched databases, it is deemed essential to systematically address this gap.