This randomized clinical trial aims to compare the effectiveness of Listerine and Chlorhexidine mouthwashes in improving periodontal health in patients undergoing fixed orthodontic treatment. Gingival Index and Plaque Index will be assessed at baseline, 2 weeks, and 4 weeks.

Orthodontic treatment using fixed appliances can significantly impair oral hygiene due to the presence of brackets, bands, and wires, which create retentive areas that promote plaque accumulation. This buildup can result in gingival inflammation, leading to gingivitis or even periodontitis if not managed effectively. Mechanical plaque control, such as brushing and flossing, is often insufficient under these conditions. Thus, adjunctive chemical plaque control agents like mouthwashes are commonly recommended.

Chlorhexidine (CHX) is widely considered the gold standard for chemical plaque control due to its broad-spectrum antimicrobial activity and prolonged substantivity in the oral cavity. However, CHX is associated with side effects such as tooth staining, altered taste sensation, and mucosal irritation, limiting its long-term use. In contrast, Listerine is a commercially available essential oil-based mouthwash that has demonstrated anti-plaque and anti-inflammatory properties without the same level of side effects.

This double-blind, randomized controlled trial aims to compare the clinical efficacy of CHX (0.12%) and Listerine mouthwash in improving periodontal health among patients undergoing fixed orthodontic treatment. The study will be conducted over a period of 4 weeks at the Orthodontics Department of Saidu College of Dentistry, Swat. A total of 60 participants (30 per group), aged between 13 and 25 years, will be enrolled using non-probability consecutive sampling. Participants will be randomized into two groups using block randomization: one receiving CHX and the other Listerine, both in identical, unlabelled bottles to ensure blinding of both the investigator and participants.

The primary outcome measures are changes in Plaque Index (PI) and Gingival Index (GI), assessed at baseline (Day 0), 2 weeks, and 4 weeks. Oral examinations will be conducted by calibrated examiners using standard indices and WHO probes. Data will be analyzed using R software, with t-tests applied to compare mean scores between groups. Age and gender will be considered as potential effect modifiers.

The study is designed to evaluate whether Listerine, as a more tolerable alternative, provides comparable or superior improvements in periodontal health compared to CHX in orthodontic patients. If proven effective, Listerine may serve as a safer, more acceptable option for long-term use during orthodontic treatment.

Inclusion Criteria:

• Aged 13-40 years
• Permanent dentition (including first molars)
• Willing to undergo orthodontic treatment and follow instructions

Exclusion Criteria:

• Systemic illness (e.g., diabetes, heart disease, hepatitis)
• Pregnant/lactating females
• Tobacco use
• History of allergies to mouthwash/toothpaste
• Use of mouthwash in past 3 months
• Abnormal oral morphology or parafunctional habits

Non Applicable

Participants will be randomly assigned to either the Chlorhexidine or Listerine group using a block randomization method. To ensure blinding, both mouthwashes will be dispensed in identical, unlabelled bottles. Neither the participants, the care providers will be aware of the group allocation throughout the study period.