A Phase 4 interventional study of Benzydamine hydrochloride mouthrinse and Placebo mouthrinse in Plaque Induced Gingival Disease and Oral Health, sponsored by University of Zagreb. Completed at 1 site in Croatia. Open to female participants, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-04.
Sponsored by University of Zagreb · Phase 4, Interventional, and Prevention
The goal of this clinical trial is to evaluate the effect of a mouthrinse containing an active ingredient benzydamine hydrochloride in the absence of daily oral hygiene. The study includes periodontally healthy female subjects and experimental phase will last for three days. Plaque accumulation is the primary evaluated outcome, measured by a particular periodontal index called Plaque Control Record (PCR). Gingival inflammation (bleeding) is the secondary evaluated outcome, measured by a particular periodontal index called Bleeding on Probing (BoP). Researchers will compare benzyadamine hydrochloride mouthrinse to a placebo (a look-alike substance that contains no active ingredient) mouthwash to see whether benzydamine hydrochloride use results in greater plaque accumulation.
This study is designed as a randomized, double-blind, placebo-controlled, parallel-group clinical trial to evaluate the effects of a benzydamine hydrochloride-containing mouthrinse on supragingival plaque accumulation and gingival inflammatory response under conditions of restricted mechanical oral hygiene. The experimental model is based on a short-term plaque regrowth protocol, enabling controlled assessment of the chemical effects of the investigational product in the absence of confounding mechanical plaque removal.
A total of 50 periodontally healthy female participants will be enrolled and randomly assigned to either the test group (benzydamine hydrochloride mouthrinse) or the control group (placebo mouthrinse). Randomization will be performed using a predefined allocation sequence to ensure balanced group distribution. Both participants and investigators will be blinded to group assignment, with the test and placebo formulations matched in color, taste, and packaging to maintain allocation concealment.
Prior to the experimental phase, all participants will receive professional dental prophylaxis to establish a standardized baseline with minimal plaque accumulation and absence of gingival inflammation. Following this, subjects will be instructed to refrain from all mechanical oral hygiene procedures, including toothbrushing and interdental cleaning, for the duration of the 3-day experimental period.
During the experimental phase, participants will use the assigned mouthrinse twice daily, rinsing with 15 mL of solution for a standardized duration according to detailed written instructions.
The investigational product contains benzydamine hydrochloride, a locally acting non-steroidal anti-inflammatory agent with analgesic and anti-inflammatory properties, which may influence gingival tissue response and potentially affect plaque accumulation dynamics. The placebo formulation is devoid of active pharmacological ingredients but is otherwise identical in formulation characteristics to ensure effective blinding.
Clinical assessments will be conducted at baseline and at the end of the 3-day experimental period. Plaque accumulation will be assessed using the Plaque Control Record (PCR), which quantifies the presence of plaque on six tooth surfaces and expresses the findings as a percentage of plaque-positive sites. Gingival inflammation will be evaluated as a secondary outcome using Bleeding on Probing (BoP), recorded dichotomously following periodontal probing.
All clinical measurements will be performed by a previously calibrated examiner using standardized instruments and probing force to ensure consistency and reproducibility of recorded data.
This study design allows for the isolation of the chemical effects of benzydamine hydrochloride by eliminating mechanical plaque control, thereby providing insight into its influence on early plaque formation and gingival inflammatory response compared to placebo. The short duration of the experimental phase ensures participant safety while allowing detection of early biological changes in plaque accumulation and gingival health.
314 studies on the registry are indexed under Dental Plaque; 54 are open to participants now.
This study's enrollment of 50 is below the median of 59 across 279 interventional studies indexed under Dental Plaque.
Browse Dental Plaque studies →University of Zagreb is the lead sponsor of 67 studies on the registry; 13 are open to participants now.
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Exclusion Criteria:
Experimental arm participants will use the assigned mouthrinse containing benzydamine hydrochloride twice daily, rinsing with 15 mL of solution for a standardized duration according to the manufacturer's instructions.
Drug: Benzydamine hydrochloride mouthrinse
Placebo mouthwash arm participants will use the assigned placebo mouthrinse, formulated to be identical in color, taste, and packaging to ensure effective allocation concealment. The mouthrinse will be used twice daily, with 15 mL of solution, following a standardized rinsing duration in accordance with the manufacturer's instructions.
Other: Placebo mouthrinse
Participants assigned to the intervention arm will use a mouthrinse containing benzydamine hydrochloride twice daily. A volume of 15 mL will be used per rinse, following a standardized rinsing duration in accordance with the manufacturer's instructions. During the 3-day experimental period, participants will refrain from all mechanical oral hygiene measures to allow assessment of the chemical effects of the mouthrinse on plaque accumulation and gingival inflammation.
Participants assigned to the placebo arm will use a mouthrinse without active pharmacological ingredients, formulated to match the test product in color, taste, and packaging to ensure blinding. The mouthrinse will be used twice daily in a volume of 15 mL, following a standardized rinsing duration in accordance with the manufacturer's instructions. Mechanical oral hygiene measures will be suspended throughout the 3-day experimental period.
3-day plaque accumulation assessed by Plaque Control Record (PCR)
Plaque accumulation will be evaluated using the Plaque Control Record (PCR), which assesses the presence or absence of supragingival plaque on six surfaces of each tooth. The results will be expressed as the percentage of plaque-positive surfaces relative to the total number of examined surfaces, providing a quantitative measure of plaque regrowth under conditions of suspended mechanical oral hygiene.
Time frame: Baseline (Day 0) and Day 3
3-day gingival inflammation assessed by Bleeding on Probing (BoP)
Gingival inflammation will be assessed using Bleeding on Probing (BoP), recorded dichotomously (presence/absence of bleeding) following gentle probing of the gingival sulcus at standardized sites. The outcome will be expressed as the percentage of bleeding-positive sites, reflecting the degree of gingival inflammatory response.
Time frame: Baseline (Day 0) and Day 3
Plan to share: No
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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University of Zagreb