Table 2: The selection criteria of the volunteers.

Inclusion Criteria	Exclusion Criteria
1. The volunteers were healthy with ages above 18 years.	1. The volunteer had oral lesions on the buccal mucosa.
2. The volunteers had the same number of teeth on the left and right side of their mouth.	2. The volunteer had poor blood circulation,
3. The volunteers had ASA physical status of I or II.	3. The volunteer had allergies to chlorhexidine or lidocaine.
4. The volunteers had the intact oral mucosal membrane.	4. The volunteer use antimicrobial mouthwash prior to the experiment.
	5. The volunteer received antibiotics within 2 weeks prior to the study.