This is a pilot study. The investigators hypothesize that the peri-implant soft tissue response to de novo plaque accumulation is similar to that of normal gingival tissue in the same subjects.

The investigators propose to conduct a controlled clinical trial to evaluate peri-implant soft tissue response to de novo plaque accumulation in comparison to the response of gingival tissue in the same subjects

Inclusion Criteria:

-Male and Female ³21 years of age.

Oral site specific inclusion criteria:

• 1) Presence of 2 implants in the maxillary or mandibular arch supporting fixed restorations in function for at least 1 year (Test)
• 2) Presence of 2 teeth in the corresponding position of the implant (Control); -3) Absence of active infections at both test and control sites
• 4) Absence of radiographic bone loss at both test and control sites
• 5) Pocket depth ≤4mm at both test and control sites
• 6) must give written informed consent.

Exclusion Criteria:

• 1) Treatment with antibiotics for any dental or medical condition within 1 month before screening
• 2) Systemic diseases that require chronic use of anti-inflammatory medications, antibiotics or anticoagulants
• 3) Ongoing medications for systemic conditions initiated <3 months before the start of the study or the requirement to take prophylactic antibiotics for invasive dental procedures
• 4) Significant organ disease including impaired kidney function, heart murmur, rheumatic fever, bleeding disorder
• 5) Active infectious diseases such as hepatitis, tuberculosis and HIV
• 6) Clinically detectable caries and periodontal disease
• 7) Tobacco use of any kind
• 8) Use of medications affecting periodontal status (diphenylhydantoin, cyclosporine etc.)
• 9) No pregnancy or lactation or expectation to become pregnant within next 3 months.

Participants will be excluded from the study or analysis if any of the following occur during the study: 1) Changes in the patient medical status or medications that met the exclusion criteria; 2) Use of antimicrobial rinses; 3) Use of irrigating devices; 4) Subject noncompliance with stent wearing during the experimental mucositis/gingivitis phase and/or Vitamin C use; 5) Use of anti-inflammatory drugs or antibiotics; 6) allergic history to common toothpaste or mouth rinse ingredients.

Acute use of acetaminophen will be permitted.