The aim of this investigation is to evaluate the impact of the 14- day consumption of a nitrate-rich diet on the the extent of gingival inflammation in a cohort of periodontal aftercare patients. Recorded parameters were gingival index, plaque control record, salivary nitrate/nitrite level and vascular parameters

This investigation evaluated the impact of a nitrate-rich diet on the extent of gingival inflammation in a cohort of periodontal aftercare patients. Forty-four (23 test/21 placebo) periodontal aftercare patients with chronic gingivitis were enrolled. At baseline, gingival index (GI), plaque con- trol record (PCR) and salivary nitrate level (SNL) were recorded, followed by sub- and supragingival debridement. Subsequently, participants were randomly provided with 100 ml bottles of a lettuce juice beverage to be consumed 39 daily over 14 days, containing either a standardized amount of nitrate resulting in an intake of approximately 200 mg nitrate per day (test) or being devoid of nitrate (placebo).

Inclusion Criteria:

• number of teeth ≥ 10
• body mass index (BMI) ≥ 24 ≤ 30
• presence of mild to moderate gingivitis (Gingiva Index > category GI 0 ≤ category GI 2) at a minimum of 3 teeth
• history of periodontal disease and inclusion in a regular scheme of supportive periodontal therapy (regularly repeated subgingival biofilm removal 2-4 x/year)

Exclusion Criteria:

• manifestation of severe gingivitis (Gingiva Index = 3) at any tooth
• manifestation of inflammatory oral mucosal diseases other than gingivitis
• xerostomia (salivary flow ≤ 0.1 ml/minute)
• inability for regular oral home care
• known allergies and intolerances to any of the ingredients of the experimental juice beverages
• inability to follow the study protocol due to intellectual or physical handicaps

Patients were allocated using a computer-generated randomization list in blocks of six either to the test or the placebo group. Assignment to a participant number was done according to the chronological order of enrolment in the study. All therapeutic and diagnostic interventions were performed at the Department of Periodontology of the University Hospital of Wuerzburg. All examinations were performed by two experienced, inter- and intra-calibrated periodontists not being involved in patient assignment and hand out of the experimental juices respectively.