Competitive environments, fear, guilt, anxiety, restlessness, anger, disorganization, bills, unemployment, poor sleep, etc. are factors that usually cause emotional stress. Related to these factors are several systemic and oral diseases, such as non- carious lesions (abfraction, erosion, abrasion, wear), periodontitis, xerostomia, burning mouth syndrome, autoimmune diseases (e.g oral lichen planus) and cancer that might by triggered by the immunological disturbance that is caused by con- tinuous persistent and no-functional stress.