Background: Deficient gingiva between teeth that sometimes occur after fixed orthodontic treatment, has significant appearance and dental health implications. The gaps between teeth can disrupt smile harmony and increase risk of food impaction, leading to food impaction, bacterial colonisation, and plaque accumulation. Objectives: This study assessed the reconstruction of deficient interdental gingiva (DIG) using injections of umbilical cord-mesenchymal stem cells (UC-MSC) compared to physiological saline in post-treatment orthodontic patients. Methods: This two-arm, parallel, double-blinded, randomised controlled trial included 21  DIG from participants aged 20 to 40 years, randomly assigned to receive either UC-MSC or physiological saline injections at six-week intervals over three sessions. Soft tissue from intraoral scans at week 0, 6, 12, 24, and 36 were superimposed and volumetric changes analysed.  Results: No statistically significant differences were found in interdental gingiva volume within or between the UC-MSC and control groups (p > 0.05). Pain scores were zero, with no notable adverse effects.  Conclusion: There were no significant post-intervention changes in DIG reconstruction with either UC-MSCs or physiological saline. No complications were observed during the 6-month observation period. Further studies involving larger sample sizes and longer follow-ups can better evaluate the regenerative potential of UC-MSCs and assess possible long-term complications. Investigating alternative stem cell sources and combination therapies may enhance outcomes. Maintaining strict oral hygiene remains critical for controlling inflammation and optimising the regenerative effects of UC-MSCs.

Keywords

Deficient interdental gingiva, stem cell, reconstruction, saline, orthodontics