Effects of a 4-week free-sugar avoidance during periodontal therapy: An explorative randomized controlled clinical trial

Background: This study investigated the effect of a 4-week free-sugar avoidance on periodontal parameters during periodontal therapy. Methods: Twenty-one patients with untreated periodontitis and daily free-sugar intake were allocated to a sugar avoidance group (SAG) and a control group (CG). The SAG received a 45-min dietary consultation and was instructed to avoid free sugars during the following 4 weeks after subgingival instrumentation, while the CG continued with their regular diet. Bleeding on probing (BOP), plaque control record, body weight (BW), visceral fat (FATv), and a food frequency questionnaire (FFQ) were collected at baseline (T1), 4 weeks (T2), and 8 weeks (T3) after subgingival instrumentation. Results: The main outcome parameter BOP was significantly reduced at T2 by 40.3% +/- 15.54 in the SAG and 34% +/- 12.47 in the CG (intra-p value both <0.001, inter-p value 0.361). A linear regression analysis of changes at patient level adjusted for age and FATv revealed a significant group difference for BOP (regression coefficient = -6.8; p = 0.019). Significant reductions were observed in BW, FATv and mean daily intake of free sugars (-14.4 g/day), and a significant increase of vitamin C derived from fruits (75.89 mg/day) at T2 in the SAG only. Conclusion: This study may indicate additional beneficial effects of a sugar avoidance on periodontal and metabolic parameters, and nutritional intake during periodontal therapy. German Clinical Trials Register (DRKS00026699).