A double‐blind randomised clinical trial of two techniques for gingival displacement

Abstract

Knowledge about security and the potential damage originated by the gingival displacement techniques has not been described through randomised clinical studies. This crossover, double-blind, randomised clinical trial evaluated clinical and immunological factors related to conventional and cordless gingival displacement (GD) techniques, and patients' perceptions in 12 subjects with the employment of 2 GD techniques: conventional (gingival cord + 25% AlCl3 astringent gel) and cordless (15% AlCl3 astringent-based paste). In each subject, two anterior teeth were treated and a 10-day wash-out period separated the two treatments. Periodontal indices were evaluated before (baseline) and 1 and 10 days after GD. Interleukin 1β, interleukin 6 and tumour necrosis factor α concentrations in gingival crevicular fluid were measured before and 1 day after GD. Subjective parameters (pain, unpleasant taste and stress) were also evaluated. Data were analysed by one-way repeated-measures analysis of variance and Tukey's test (immunological factors), the Friedman test (periodontal parameters) and Fisher's exact or chi-squared test (subjective parameters), with a significance level of 95%. Gingival bleeding index, probing depth and plaque index values did not differ significantly between groups at any timepoint. Neither technique resulted in worse periodontal indices. Both techniques yielded similar results for pain and unpleasant taste, but conventional GD was significantly more stressful than cordless GD for volunteers. Both treatments significantly increased mean concentrations of the three cytokines, with the conventional technique producing the highest cytokine levels. Cordless GD is less stressful for patients and results in lower post-treatment levels of inflammatory cytokines compared with conventional GD.

Efficiency of Cordless Versus Cord Techniques of Gingival Retraction: A Systematic Review

“…In three articles, cord techniques were less efficient in controlling bleeding and to lesser extent, when nonimpregnated cords were used. On the other hand, Sarmento et al reported no difference in hemostasis control between cord and cordless gingival retraction techniques, possibly due to the synergistic use of a hemostatic agent (Viscostat; Ultradent).…”

“…Four studies commented on the influence of cords or paste on gingival/periodontal health. Three studies reported greater traumatic injury when cords were packed in the sulcus, resulting in an increased tendency for gingival recession, although Sarmento et al failed to identify any significant difference between both techniques.…”

Gingival Retraction Methods: A Systematic Review

“…The results exhibited no statistically significant difference in the gingival recession, PI, BOP, and AL from the baseline to 12 months of Merocel placement. A double‐blind randomized clinical trial of two techniques was undertaken by Sarmento et al . Cord with astringent and Expasyl paste were incorporated, and neither of the two techniques resulted in any significant change in the periodontal indices.…”

“…Gingival retraction methods can cause an inflammatory response mainly due to mechanical trauma or the chemical agents present in the astringents . According to Feng et al, the gingival retraction can result in increased levels of pro‐inflammatory cytokines, which can cause gingival recession.…”

The periodontal restorative interface: esthetic considerations

“…Furthermore, this was recently confirmed in a double‐blind randomized clinical trial in which gingival cord with 25% aluminium chloride astringent gel and a 15% aluminium chloride astringent‐based paste cordless displacement material were compared. Neither technique resulted in worse periodontal indices at 10 days after retraction; however, lower post‐treatment levels of inflammatory cytokines were present after the use of the paste cordless displacement material compared with the cord . Further research in this area is needed.…”