Inclusion Criteria:  Residents of Lo-Sheng sanatorium of the Ministry of Health and Welfare, Taiwan Compliant with the presence of more than four teeth in each of the upper and lower four regions Those who have not used antibiotics and mouthwash two months before the test  Exclusion Criteria:  Moderate to severe dementia CDR (Clinical Dementia Assessment Scale) is greater than or equal to 2 points or more Those with a score of less than 17 on the MMSE Simple Mind Scale Nasogastric Tube Inserters Those who are allergic to mouthwash Those who are on course of antibiotics and steroids Those who have had dental cleansing within one month