This study is for people at least 21 years old who have signs of problems, like swollen gums and shrinking bones, by dental implants.

At Visit 1, the dentist will:

• do an oral exam
• ask some questions
• decide if the person qualifies for being in the study
• make an appointment for Visit 2 if they qualify

At Visit 2 (Baseline), the dentist will:

• do a special cleaning of the implants

• examine the whole mouth

• collect some fluid

• take x-rays

• put the people into one of two groups (taking into account whether or not they smoke)

  1. one group will have the study antibiotic put on all the areas in their mouth with gum problems
  2. the other group will not receive the antibiotic At Visit 3 (about a month later), only fluid samples will be collected.

At Visit 4 (about 3 months later), the dentist will:

• collect fluid samples
• examine the whole mouth
• apply the antibiotic again for people in that group

At Visit 5 (about 6 months later), the dentist will:

• collect fluid samples
• examine the whole mouth
• take x-rays

Inclusion Criteria:

• 21 years of age and good general health
• appropriately documented Informed Consent
• willing to adhere to the study schedule, prohibitions and restrictions specified in the protocol
• female subjects must meet the pregnancy and contraceptive requirements
• must have oral health appropriate for study inclusion

Exclusion Criteria:

• oral health inappropriate for study inclusion
• females self-reporting pregnancy or lactation, or having a positive urine pregnancy result
• reporting any of the following conditions:
• allergy to a tetracycline-class drug
• systemic medical conditions requiring antibiotic prophylaxis prior to invasive dental procedures
• active systemic infectious disease such as hepatitis, human immunodeficiency virus (HIV) or tuberculosis
• diagnosed with clinically significant or unstable organic disease, or compromised healing potential, heart murmurs, histories of rheumatic fever, valvular disease or prosthetic joint replacement
• participation in a dental clinical trial or use of an investigational drug within 30 days of enrollment
• employees of the Investigator or study center, with direct involvement in the proposed study or other studies, as well as family members of the employees or the Investigator
• anyone who the investigator determines should not be included in the study for any reason that could compromise safety or the analysis of study results

180 Days

Adverse Events were a primary outcome measure, so we have used a 1% reporting threshold, rather than the standard 5%