* Study design This is a randomized controlled single blinded clinical trial, with split mouth design.
* Sample size Forty seven subjects with fixed orthodontic appliance were recruited from patients attending dental teaching clinics at Jordan University of Science and Technology. The age range was between 18 and 35 years. They were randomly assigned to use interdental brush on one side of the mouth, and water floss on the other side in a split mouth design.
The study lasted for 3 months.
1. Inclusion criteria:
1\. Patients with fixed orthodontic appliance in the upper and lower arches. 2. Patients with healthy gingiva with no periodontal disease. 3. Patient's orthodontic plan doesn't require extraction of any teeth during the study period. .
4\. Patients should have at least 26 teeth. 5. Patients are motivated and able to clean their teeth. 6. Patients should not have caries, overhang restorations, crowns, bridges or implants 7. Adults 18-35 years old.
2. Exclusion criteria:
1\. Smokers 2. Medically compromised patients 3. Pregnant woman.
* Ethical considerations The study was approved by the Institutional Review Board (IRB) of Jordan University of Science and Technology (51/166/2024). All participating patients were informed of the study's purpose, objectives, and methods. They all provided a written informed consent before data collection.
* Data collection:
1. Patients randomly used water floss on one side of the mouth , and the interdental brush on the other side.
2. Randomization was used to assign the intervention to either the left or right side of the mouth.
The following will be assessed
1- Plaque score using Rustogi modified navy plaque index for buccal and lingual surfaces, where the tooth was divided into multiple zones as the following :
The divided zones are:
Whole mouth: areas A,B,C,D,E,F,G and H. Marginal (gum line): areas A,B and C. Interproximal: areas D and F
0 score was given the area where there is no plaque.
1 score was given in the area where there is plaque Intraoral photos using professional camera were taken for all teeth and all surfaces to record the plaque score.
2\. gingival inflammation was recorded using gingival index at six sites per tooth (distobuccal, midbuccal, mesiobuccal, distolingual/palatal, midlingual/palatal, mesiolingual/palatal) as follows : 0= Normal gingiva.
1. Mild inflammation - slight change in colour and slight edema but no bleeding on probing.
2. Moderate inflammation - redness, edema and glazing, bleeding on probing.
3. Severe inflammation - marked redness and edema, ulceration with tendency for spontaneous bleeding.
3.Visual Analog Scale (VAS) visual analog scale from 0 - 10 (0 - unsatisfied, uncomfortable, or difficult to use, 10 -very satisfied, comfortable, and easy to use) in each visit was taken.
Randomization and Blinding Independent of the clinical assessment, a third-party dentist used a computer-generated random number sequence to determine which side of each patient's mouth will be cleaned by interdental brush and which side will be cleaned by the oral irrigator. While participants were aware of which device they were using on each side, the examiner who performed the clinical examinations was blinded.
* Adverse events monitoring: Participants were monitored for adverse events during the study period such as gingival trauma, sensitivity, recession, tooth or restoration damage.
