Free sugars and gingival inflammation: A systematic review and meta-analysis

Consumption of free sugars has been associated with chronic non-communicable diseases. The aim of the study was to investigate the effect of free-sugar consumption on gingival inflammation using a systematic review and meta-analysis based on the PICO question 'What impact does the restriction of free sugars have on the inflammation of gingival tissue?'

Literature review and analyses were based on the Cochrane Handbook for Systematic Reviews of Interventions. Controlled clinical studies reporting on free-sugar interventions and gingival inflammation were included. Risk of bias was performed with ROBINS-I and ROB-2, and effect sizes were estimated with robust variance meta-regressions.

Of the 1777 primarily identified studies, 1768 were excluded, and 9 studies with 209 participants with gingival inflammation measures were included. Six of these studies reported on the dental plaque scores of 113 participants. Restriction of free sugars, when compared with no such restriction, was associated with statistically significantly improved gingival health scores (standard mean difference [SMD] = -0.92; 95% confidence interval [CI]: -1.43 to -0.42, p < .004; I² [heterogeneity] = 46.8) and a trend towards lower dental plaque scores (SMD = -0.61; 95% CI: -1.28 to 0.05, p < .07; I²  = 41.3). The observed improvement of gingival inflammation scores with restricted consumption of free sugar was robust against various statistical imputations. No meta-regression models were feasible because of the limited number of studies. The median publication year was 1982. Risk-of-bias analysis showed a moderate risk in all studies.

Restriction of free sugar was shown to be associated with reduced gingival inflammation. The systematic review was registered at PROSPERO (CRD 42020157914).