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

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.