Decontamination of the implant surface plays a pivotal role in managing peri-implant diseases. Various techniques have been suggested for surface decontamination such as dental lasers. To achieve optimal outcomes, it is important to differentiate between adjunctive and alternative laser application at the recommended settings for sulcular debridement and implant surface disinfection. This article presents a comprehensive literature review of the current understanding of laser-assisted treatments for both non-surgical and surgical management of peri-implantitis. Additionally, a treatment flowchart is provided, outlining the characteristics and benefits of the lasers discussed. Based on current evidence, Er:YAG and Er,Cr:YSGG lasers emerge as the most promising types for the management of peri-implantitis. However, further research and clinical studies are necessary to establish standardized protocols and optimize the use of laser therapy in managing peri-implantitis effectively.
Peri-implantitis is a biological complication that affects dental implants. It is characterized by a nonspecific inflammatory reaction induced by a bacterial biofilm that affects both soft and hard tissues, leading to progressive peri-implant bone loss and the formation of a pocket and inflammation in peri-implant tissues (Schwarz et al. 2018). As dental implants continue to gain popularity, peri-implantitis poses a significant challenge in preventing and treating associated complications. Peri-implant mucositis is considered a prevalent condition, and the risk of developing peri-implantitis can be influenced by various factors related to both the patient and the implant (Derks et al. 2016). According to a systematic review and meta-analysis (Diaz et al. 2022), the prevalence of peri-implantitis was 19.53% (95% CI 12.87-26.19) at the patient level and 12.53% (95% CI 11.67-13.39) at the implant level. However, the variability in prevalence can depend on different factors, including the follow-up period, disease definition, and individual risk factors.
Treating peri-implantitis poses challenges in both non-surgical and surgical management. The primary objective in addressing peri-implantitis should be the complete elimination of biofilm that accumulates on intricate surfaces of dental implants. This approach can effectively resolve inflammation in the surrounding soft tissue and halt the progression of bone loss. Various techniques exist for decontaminating implant surfaces, each capable of altering the chemical and physical characteristics of the implant surface. These methods include mechanical debridement approaches, chemical strategies, power-based air abrasive, implantoplasty, phototherapy, or laser-assisted strategies (Figuero et al. 2014; Monje et al. 2022; Parma-Benfenati et al. 2013). Recently, the EFP S3 level clinical practice guideline recommends against using air-polishing or Er:YAG laser for implant surface decontamination during peri-implantitis surgery. Instead, titanium brushes may be considered as an alternative or adjunct. There is insufficient evidence to recommend implantoplasty, and the overall quality of evidence is low, indicating a need for further research in this area (Herrera et al. 2023).
Although current evidence suggests that there are no available treatments that can completely resolve established peri-implantitis, the laser may play an important role in its treatment due to its multiple effects on tissues. These effects occur according to the power emitted by the laser. If it is high power, so-called high-level laser therapy (HLLT), ablation or vaporization, hemostasis, microbial inhibition, and destruction will be implemented along with heat generation. Conversely, if the power is less than 670mW/cm2, known as lower-level laser therapy (LLLT), biological effects such as photomodulation or photobiostimulation (PBM) take over (Asnaashari & Safavi 2013; Mizutani et al. 2016). The impact could potentially stem from photochemical reactions occurring within cells rather than thermal occurrences. Nevertheless, the exact mechanism of PBM remains ambiguous. LLLT can also appear simultaneously with HLLT by energy penetrating or scattering in the surrounding tissues. Furthermore, laser therapy may also help alleviate a patient's physical and mental stress and reduce pain during and after surgery (Aoki et al. 2015).
Various types of lasers with different wavelengths are available for treating peri-implantitis. If classifying the lasers based on source materials, the common types used in dentistry are the erbium-doped yttrium-aluminum-garnet (Er:YAG) laser, the erbium, chromium-doped yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser, diode lasers, carbon dioxide (CO2) lasers, neodymium-doped yttrium-aluminum-garnet (Nd:YAG) lasers. If classifying the dental lasers based on wavelength, most of them fall into two categories: one is near infrared (NIR) laser, 700nm – 1400nm, including diode laser and Nd:YAG laser; the other is far infrared (FIR) laser, including Er,Cr:YSGG (2780nm), Er:YAG (2940nm), and CO2 (10600nm) laser. The laser wavelengths used for decontaminating implant surfaces should ideally have strong absorption in water, enabling them to effectively vaporize any water-based biofilm and inflammatory granulation tissue. Among these lasers, the Erbium laser (Er:YAG and Er,Cr:YSGG) exhibited the highest water absorption coefficient (Aoki et al. 2004, Aoki et al. 2015). On the other hand, if the benefit of LLLT is anticipated, the incorporation of NIR irradiation with monochromatic or narrow-band wavelengths is suggested (Pires et al. 2011).
It is noteworthy that the Nd:YAG laser has been found to commonly cause extensive melting on titanium (Ti) surfaces, regardless of the surface treatments, and it is generally considered contraindicated for use on Ti implant surfaces (Kreisler et al. 2002; Romanos et al. 2000). However, some researchers have cautiously used the Nd:YAG laser around the implant for its benefits of deep tissue decontamination, microbial load reduction, and photobiomodulation, without direct contact with the implant surface. In cases where the Nd:YAG laser was employed, decontamination of the implant surface was performed using an ultrasonic instrument with diluted chlorhexidine (CHX) (Strauss et al. 2021) or Er:YAG laser ((Fragkioudakis et al. 2023) in combination.
Fundamentally, studies have suggested that the Erbium laser is effective in removing calculus from cementum (Aoki et al. 2000) and also a more favorable approach for eliminating calcified deposits on the micro-structured surface of Ti implants. In addition, it causes less harm or thermal damage compared to mechanical debridement techniques and other types of laser (Kreisler et al. 2002; Matsuyama et al. 2003; Schwarz, Rothamel et al. 2003; Strever et al. 2017; Takagi et al. 2018). Nevertheless, the majority of studies have shown limited benefits associated with the adjunct application of diode laser or PDT in the treatment of peri-implantitis (Aimetti et al. 2019; Albaker et al. 2018; Papadopoulos et al. 2015; Roccuzzo et al. 2022; Tenore et al. 2020). It is essential to operate the lasers at the manufacturer's recommended setting for sulcular debridement and implant disinfection. It should be noted that using different parameters such as power, pulse duration, and repetition rate can lead to varying outcomes. The optimal energy output varies between manufacturers due to each having a unique energy profile, which stems from intrinsic differences in their laser delivery systems (Takagi et al. 2018). The characteristics and overall benefits of the lasers are summarized in Table 1.