The impact of retraction cords on the gingival margin level: A randomized clinical trial

Purpose

To examine the impact of placing plain and impregnated retraction cords for two different retraction times on the postoperative gingival margin level and periodontal health.

Materials and Methods

A total of 40 endodontically treated mandibular first molars were selected and randomly allocated into four groups (n = 10/group); A: plain retraction cord for 10 min, B: plain retraction cord, 20 min, C: impregnated (25% aluminum chloride (AlCl₃) retraction cord, 10 min, D: impregnated retraction cord (25% AlCl₃), 20 min. Intraoral digital scans were acquired, and periodontal parameters (Plaque index [PI], Bleeding on probing [BOP], and probing depth [PD]) were assessed at baseline, 7 days, and 28 days after retraction. The digital scans were superimposed to measure the change in the mid-buccal gingival margin level. Statistical differences between groups at the threetime points were tested using one-way ANOVA and Chi-square tests (α = 0.05).

Results

AlCl₃-impregnated retraction cord for 20 min resulted in a statistically significant change in gingival margin level than limiting its application to 10 min or using plain cords at the three-time points (p < 0.05) with 88 ± 4 µm gingival recession after 28 days. The assessed periodontal parameters only showed a significant difference between groups in BOP after 7 days of retraction (p = 0.0009); however, all parameters returned to normal after 28 days with no significant difference between groups (p > 0.05).

Conclusions

To avoid transient gingival inflammation or permanent gingival recession, no matter how small, the retraction time of AlCl₃-impregnated cords should be limited to no more than 10 min.