## 1 Introduction  
Ooseointegrated dental implants are an effective treatment for missing teeth with high survival rates. However, peri-implantitis is one of the major complications for supporting bone destruction leading to a loss of the implant [1; 2; 3; 4]. Peri-implantitis is an inflammatory lesion affecting the surrounding tissue of an osseointegrated implant resulting from bacterial infection and biofilm formation [5; 6; 7]. Treatments of peri-implantitis aim at bacterial controls and decontamination to promote re-osseointegration [3; 7; 8]. Effective decontamination of the infected surface is crucial, and various decontamination methods have been proposed in the literature [1; 4; 9; 10; 11]. Despite numerous suggested effective decontamination methods from multiple studies, a consensus on gold standards for peri-implantitis treatments remains elusive. Additionally, challenges persist in the re-osseointegration of previously contaminated implants [1; 2]. Decontamination methods for peri-implantitis include mechanical debridement using scalers and ultrasonic scalers with plastic, metal, or carbon fiber tips, air-polishing systems, and lasers. Alternative approaches to treatment comprise disinfection modalities, such as antiseptics, photothermal laser disinfection, photodynamic therapy, the administration of local or systemic antibiotics, or a combination of these methods [5; 12; 13; 14; 15]. Air-polishing therapy is one of the mechanical decontamination methods, involving the use of low-abrasive powders, water, and pressurized air to remove biofilm from implant surfaces through abrasion. Various types of abrasive powders are available, including sodium bicarbonate, glycine salt, aluminum trioxide, and calcium carbonate [16]. Compared to sodium bicarbonate powders, in vitro and in vivo studies have demonstrated that glycine powders are less abrasive, safe, and effective for biofilm removal [17; 18; 19]. Various types of lasers, including neodymium-doped yttrium aluminum garnet (Nd:YAG), erbium-doped yttrium aluminum garnet (Er:YAG), erbium-chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG), and carbon dioxide (CO2) lasers, have been used for periodontal treatments [7; 20]. The erbium family lasers that produce middle infrared lasers, Er:YAG and Er.Cr:YSGG, have gained attention for their efficacy in treating peri-implantitis [21]. The Er:YAG laser has demonstrated potent bactericidal properties and an ability to neutralize bacterial toxins against periodontal pathogens [7; 15; 22]. Chlorhexidine gluconate is a diphenyl compound with broad-spectrum antibacterial properties, acting by altering bacterial cell membranes and causing leakage and subsequent cell destruction [23]. Chlorhexidine is reported as a chemical antiseptic that can be used as a decontamination method in peri-implantitis [16]. Chlorhexidine demonstrates a bactericidal effect and the inhibition of biofilm formation [20]. Also, chlorhexidine has been shown to contribute to re-osseointegration in peri-implantitis lesions [16; 24]. Bone density quantifies the size of the marrow space relative to the bone volume and serves as a valuable metric for assessing the quality of osseointegration in decontaminated implants [25]. The fractal dimension (FD) is a quantitative value for evaluating the trabecular bone pattern [26]. This method involves statistical analysis of the structural patterns in the fractal dimension and is independent of projection geometry and radiodensity; thus, it is widely employed in the dental field, including the evaluation of implant stability [27; 28]. As inflammation in the bone progresses, the trabecular bone is destroyed, and lower FD values are obtained [25]. Also, the mean grayscale value (GV) serves as the metric for quantifying bone density measurements [25; 29]. The mean GV demonstrates the intensity of attenuated X-rays using a numerical scale.