Inclusion Criteria:  Participants in the study are children aged 6-12 years, compliant with the cognitive development of the child and the requirement for complete root development; Children, requiring conservative treatment of occlusal carious lesions on a second primary molar, without spontaneous unprovoked pain, percussion or palpation pain or other symptoms, indicating pulp involvement or periodontal pathology. Lesions are classified as distinct cavity with visible dentin without prior restoration or sealants by the International Caries Detection and Assessment System (ICDAS) with code 05. Included are caries lesions only on vital teeth. Children with one or more permanent molars giving indications for pit and fissure sealing; Patients without previous experience with laser treatment of carious lesions; Children who are not considered medically compromised or medically complex patients; Verbal assent from the child willing to comply with all study procedures and protocol; Obtained written informed consent by the patient's parent/guardian for participation in the study  Exclusion Criteria:  Patients who were undergoing therapy with neurological, sedative, analgesic, and/or anti-inflammatory drugs 7 days prior to treatment that might affect heart rate; Children, who were first-time dental patients; Children with systemic diseases or physiological development delays; Children with mental or cognitive problems; Present infectious diseases such as influenza, scarlet fever, etc. Excluded are molars which are affected by disturbances in the development of dental structures (hypoplasia, hypomineralization, fluorosis)