The effect of chlorhexidine mouthwash on gingival health around stainless steel crowns in primary molars

Aim: Stainless steel crowns (SSC), widely used in pediatric dentistry, may cause gingivitis and discomfort. In this study, we investigated the effect of these crowns on gingival index (GI), periodontal probing depth (PPD), Oral Hygiene Index-Simplified (OHI-S), and the effect of chlorhexidine (CHX) mouthwash on reducing these indices in crowned teeth. Materials and Methods: A randomized double-blind controlled trial was conducted on 56 healthy children aged 4 to 9 years old requiring pulpotomy and SSC on mandibular primary molars. Patients were randomly divided into control and intervention (using chlorhexidine mouthwash) groups. In the second session, two weeks later, GI, OHI-S, and PPD were measured in previously crowned and controlled teeth. Statistical analysis: Non-parametric tests Mann-Whitney and Wilcoxon were used to analyze OHI-S, PPD, and GI scores between groups. Results: Comparing SSC-restored teeth between the intervention and control groups showed OHI-S and GI indices were lower in the intervention group and this difference was significant (P = 0.004), (P=0.003), however PPD in crowned teeth did not differ significantly between the two groups (P> 0.05). In the control group, GI and PPD increased significantly in crowned teeth, while plaque accumulation remained unchanged. In contrast, the CHX group showed no significant differences between crowned and control teeth. Conclusion: Chlorhexidine mouthwash usage improved gingival health, and decreased plaque accumulation. Therefore, providing instructions about using mouthwash after placing SSCs especially in patients with poor oral hygiene is recommended. Trial registration: This trial was registered at the Iranian Registry of Clinical Trials (IRCT) on April 17, 2021, under registration number IRCT20210417050994N1.