Role of Essential Oil-Based Mouthwashes in Controlling Gingivitis in Patients Undergoing Fixed Orthodontic Treatment. A Review of Clinical Trials

Essential oil (EO)-based mouthwashes have been used for oral health maintenance due to their antimicrobial and anti-inflammatory properties. The aim was to review clinical trials that assessed the role of EO-based mouthwashes in controlling gingivitis in patients undergoing fixed orthodontic treatment (OT). The Patients, Interventions, Control and Outcome (PICO) format was based on the following: (a) P: Patients undergoing fixed OT (b) Intervention: EO-based mouth-wash; Control: Mouthwashes that did not contain EOs or no mouthwash (d) Outcome: Control of gingivitis measured by clinical indices. Databases were searched manually and electronically up to and including May 2021 using different medical subject subheadings. Data screening and extraction were performed. The risk of bias within randomized controlled trials was assessed using the revised Cochrane Collaboration’s risk of bias tool (RoB 2). The Risk of Bias In Non-randomized Studies—of Interventions (ROBINS-I) tool was used for non-randomized controlled trials. Disagreements related to literature search and RoB evaluations were resolved via discussion. Six clinical studies were included. Four studies showed that Listerine(®) is effective in controlling gingivitis in patients undergoing fixed OT. One study reported that the use of 5% Fructus mume mouthwash resulted in a significant reduction in gingival bleeding. Two mouthwashes that contained 1% Matricaria chamomilla L. and 0.5% Zingiber officinale were also found to be efficient in controlling gingival bleeding. Four, one and one studies had a low, moderate and high RoB, respectively. In conclusion, EO-based mouthwashes seem to be effective for the management of gingivitis among patients undergoing fixed OT. Further well-designed and power-adjusted clinical trials are needed.