## 1 Introduction  
Implant-supported prosthesis is considered one of the finest and most common approaches used to replace missing teeth [1]. About 12 million dental implants are placed every year worldwide [2]. However, a significant increase in peri-implant diseases was recently described. Similar to periodontal diseases, the main cause of peri-implant diseases is dental plaques, which supports correlated pathogenic bacterial growth [3]. Indeed, periodontal health is influenced by various factors such as oral hygiene, genetic and epi-genetic factors, systemic health, and nutrition [4, 5]. The recent literature shows that the prevalence of peri-implantitis is equal to 10% of the implants and 20% of the patients, while peri-implant mucositis affects about 30% of the sites and 50% of the subjects treated [2]. However, despite many preventive treatment approaches being suggested, nowadays, it is not possible to identify a reliable and consistent therapy for the treatment of these pathologies [6]; the prevention and sudden management of early symptomatology appear to be the most effective protocol [7; 8]. Indeed, it is known that the incidence of peri-implant diseases can be minimised through routine dental biofilm control. Recently, laser therapies have gained acceptance for the management of peri-implant mucositis [6]. Systematic reviews point out the wide range of wavelengths, powers, energies, time, and number of applications suggested for peri-implant disease treatments, leading to the conclusion of a non-univocal approach [9; 10; 11; 12]. However, semiconductor lasers such as diodes and solid-state lasers, including 1064-nm Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) and Erbium:YAG, seem to better support laser therapy advances [13]. Indeed, according to the wavelengths employed and the therapy parameters administered, several laser features through photodynamic therapies and photobiomodulation as well as surgery can be exploited. Therefore, diseased tissue may be removed [7; 8], inflammation reduced [11], and wound healing improved [14]; pathogenic bacteria can be killed or inhibited, and natural microbiota can be stimulated [15]. In particular, the evidence-based literature shows that laser therapies can decontaminate the implant surface and surrounding areas [6] and stimulate disease-impacted tissue recovery [9; 16; 17]. However, the incomplete knowledge of interactions between the peri-implant titanium with laser wavelengths and clinical parameters limits the laser application in peri-implantitis management [18]. The authors suggested that lasers can damage titanium screws because of temperature and trigger tissue necrosis [19] and microbiota biofilm alterations [20]. Therefore, despite the effective support of laser therapies, the clinical application remains operator-dependent. Recently, promising results on peri-implantitis were obtained by [PERSON] and collaborators [21] using a new 1064-nm Q-switch Nd:YAG nanosecond pulse. Indeed, effective decontamination with the 1064-nm Nd:YAG laser was observed. However, its effects on implant prosthesis materials such as titanium are not yet fully known. Therefore, our comparative in vitro study aimed to test the effects of 1064-nm Q-switch Nd:YAG nanosecond pulse on titanium surfaces. Plus, the new laser effects were compared with 1064-nm Nd:YAG and 980-nm diode lasers routinely employed for peri-implantitis management through laser therapy [11]. The predictor variable of this study was the peculiar ability of the 1064-nm Q-switch Nd:YAG nanosecond pulse to emit pulses in nanoseconds (ns) and provide a peak power of about 25 kW [21]. The primary variable was to point out the effect of this laser on titanium surfaces. The secondary object of the investigation was to show the reliability of 1064-nm Q-switch Nd:YAG nanosecond pulse employment compared to the 1064-nm Nd:YAG and 980-nm diode laser.