Gingival Thickness Improvement After Atelocollagen Injection-Retrospective Study.

Background

This study evaluates the increase in gingival thickness following the administration of injectable atelocollagen. Materials and

Methods

A retrospective analysis was conducted using the medical records of 60 patients with a thin gingival phenotype at baseline, treated between 2017 and 2025. All patients received a standardised protocol for soft tissue thickness modification using atelocollagen injections. Based on the continuation of maintenance therapy, patients were divided into Group A (n = 30), consisting of patients who received booster doses at six-month intervals following completion of the full treatment protocol, and Group B (n = 30), consisting of patients who did not continue maintenance therapy. The observation period for all patients was five years. Gingival thickness was assessed by periodontal probe transparency using a standard WHO probe (WHO 621) and the Hu-Friedy Colorvue Biotype Probe. Longitudinal changes were analysed using linear mixed-effects models (LMMs) for continuous outcomes and generalised linear mixed-effects models (GLMMs) with a binomial distribution and logit link for binary outcomes, accounting for repeated measurements at the patient level.

Results

Significant effects of Group and Time, as well as their interaction, were observed for the proportion of sites with a thick gingiva (Group effect: F (1,93.14) = 57.94, p < 0.001; Group × Time interaction: p < 0.001). GLMM analysis confirmed a significant Group × Time interaction (χ2 = 23.11, p < 0.001), indicating sustained gingival thickness improvement in Group A and a gradual decrease in effectiveness in Group B.

Conclusions

Injectable atelocollagen represents a reliable, effective, and user-friendly method for long-term modification of gingival thickness, particularly when supported by maintenance therapy.