Objectives: In recent years, a new field of work has been created with the use of laser beam to provide titanium surface decontamination. The aim of this study was to evaluate the effect of various laser systems in smokers and non-smokers with peri-implantitis.

Materials and Methods: According to the study protocol, patients, who were diagnosed with peri-implantitis based on the clinical and radiographic evaluations, were divided into six groups: Group 1: smokers undergoing diode laser application; Group 2: smokers undergoing Erbium, chromium: yttrium, scandium, gallium, garnet (Er, Cr:YSGG) laser application; Group 3: smokers undergoing Erbium:yttrium-aluminum-garnet (Er:YAG) laser application; Group 4: non-smokers undergoing diode laser application; Group 5: non-smokers undergoing Er, Cr:YSGG laser application; and Group 6: non-smokers undergoing Er:YAG laser application. Peri-implant sulcus depth (SD), clinical attachment level (CAL), suppuration, modified plaque index (mPI), gingival index (GI), and modified sulcus bleeding index (mSBI) were recorded and peri-implant sulcus fluid (PISF) was collected to evaluate osteocalcin.

Inclusion Criteria:

1. Presence of pocket in probing depth of ≥4 mm in at least one implant
2. No mobility in implant
3. Implants with bridge foot and opposite occlusion
4. Having no systemic disease that may affect the outcome of treatment
5. No systemic use of antibiotics for the last six months
6. Not receiving peri-implantitis treatment for the last three months
7. Individuals at the 30-60 years of age.

Exclusion Criteria:

1. Individuals who did not agree to participate in the study
2. Individuals receiving radiation therapy
3. Individuals using alcohol
4. Presence of pregnancy and lactation period
5. Individuals with parafunctional habits such as clenching or bruxism.