Three groups of individuals will be recruited: those that are orally healthy and do not have any oral discomfort (N=58), those who have gingivitis (i.e., bleeding gums; N=58), and those who have periodontal disease (N=58). The groups will be matched by gender and smoking status. Women are predicted to account for 50% of the participants. The age distribution will be 18 to 95 years. Subjects will not be excluded based on race, gender, or ethnicity.