The aim of the study was to assess the acceptability of the assisted individual and compliance with home use, as well as their clinical impact on the plaque index (PI) and bleeding on probing (BOP), with monthly reassessments allowing for continuous monitoring of all parameters.

The study was conducted as a randomized controlled clinical trial with a crossover design in patients affected by gingivitis. All data were anonymized by assigning a unique identification code to each participant. Subjects were selected according to predefined inclusion and exclusion criteria. Patients aged between 18 and 65 years with interdental spaces suitable for the use of interdental brushes were included.

At baseline (T0), all patients underwent a periodontal clinical examination, including assessment of clinical indices and documentation of initial conditions. A professional oral hygiene session was also performed using ultrasonic instruments and air flow with glycine powder. Patients received instructions for home oral hygiene using a two-tone plaque disclosing agent to highlight areas of greater cleaning difficulty. Initial intraoral conditions were documented photographically. At the end of the session, each patient was assigned to one of two treatment groups. Randomization was performed by coin toss.

All patients were provided with a supply of interdental brushes and received standardized instructions for their use. After collecting clinical indices at baseline (T0), six evaluation time points (T1-T6) were scheduled at 30-day intervals. At each time point, the following clinical parameters were recorded:

• Full Mouth Plaque Score (FMPS)
• Interdental Plaque Index
• Full Mouth Bleeding Score (FMBS)
• Papillary Bleeding Index

Measurements were performed using a standardized millimeter periodontal probe (PCP UNC 15) and a plaque disclosing agent.

At T3 (90 days), a crossover of the interdental devices between the two groups was performed: patients in Group 1 replaced the rubber interdental brush with the bristle device and vice versa. Subsequent clinical assessments were conducted using the same methods until the end of the study (T6). During each follow-up visit, a clinical reassessment was performed, including removal of any residual plaque using air polishing if necessary.

At the end of the study (T6), in addition to recording clinical indices and final photographic documentation, participants completed a 17-item questionnaire designed to assess device acceptability, frequency and method of use, and knowledge of interdental devices. All collected data were recorded digitally and processed for descriptive and comparative statistical analyses between the two treatments.

Inclusion Criteria:

• Age between 18 and 50 years
• Interdental spaces suitable for the use of interdental brushes

Exclusion Criteria:

• Age below 18 or above 50 years
• Presence of periodontitis
• Presence of generalized diastemas
• Presence of removable prostheses or orthodontic appliances
• Presence of tremors or reduced mobility of the upper limbs; adequate oculomotor coordination required
• Type 1 or type 2 diabetes
• Immunodeficiency or immunocompromised conditions (e.g., HIV infection)
• Pregnancy or breastfeeding
• Hormonal therapy
• Current pharmacological therapy with drugs known to cause gingival hyperplasia, such as phenytoin, cyclosporine, and calcium channel blockers
• Psychiatric disorders
• Heavy smoking (>10 cigarettes/day)
• Alcohol or drug abuse
• Xerostomia
• Patients with fixed dental implants