Experimental Peri-implant Mucositis in Humans

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.