Potency of hyaluronic acid from eggshell–membrane for open gingival embrasure reconstruction following orthodontic tooth movement (a histomorphological study)

Abstract

Background: The aim of this research was to assess the effectiveness of eggshell–membrane
(ESM)‑containing hyaluronic acid (HA) in the treatment of open gingival embrasure (OGE) following
orthodontic tooth movement (OTM).
Materials and Methods: This study is an in vivo quasi experimental research. A total of 24 Cavia cobaya
were equally divided into two groups, treatment (10% HA injection) and control (phosphate‑buffered
saline [PBS]). A separator was inserted between mandibular incisors to induce an OGE. A volume
of 20 μl of either PBS (n = 12) or ESM extract (n = 12) was locally injected within the interdental
papilla. Decapitation of animals was made on day 1, 4, and 7 postinjection. The staining was done
using hemotoxylin and eosin to observe angiogenesis and Mallory to observe the collagen density.
Fourier‑transform infrared spectroscopy (FTIR) and thin‑layer chromatography (TLC) analysis were
performed to detect the amount of HA available in ESM. The results were then compared with
independent t‑tests and the Mann–Whitney test. The level of statistical significance was set at 0.05.
Results: The FTIR and TLC analysis showed that HA was successfully identified in the ESM samples.
Local injection of 10% HA induced an increase of angiogenesis compared to the control group
on day 1 and 4 postinjection (P < 0.05). Significant differences (P < 0.05) were also noted in the
collagen density and the growth of interdental papilla on day 4 and 7 postinjection.
Conclusion: ESM has the potential effect of regenerating the interdental papilla construction after
OTM by increasing the collagen fiber density and inducing angiogenesis.
Key Words: Hyaluronic acid, open gingival embrasure, orthodontic tooth movement