 The purpose of this observational, non-controlled, single site trial with a retrospective design is to verify, in a large paediatric population affected by gingivitis, the tolerability and safety of 0.1 HA-based film-forming devices Gengigel Prof Fluid, Ricerfarma administered three to five times a day over a 4-week period as an adjunct to domiciliary care and oral hygiene instructions 