Effect of Hyaluronic Acid on Gingival Recession Treatment

Overview

Gingival marginal tissue recession is the displacement of the soft tissue margin apical to the cementoenamel junction (CEJ) with exposure of the root surface. It is a common clinical finding in patients with high standards of oral hygiene and can be found in more than 90% of patients. Buccal exposure of roots leading to esthetic concerns and dentinal hypersensitivity are the most frequent reasons for patients to seek treatment for the same. Gingival recession therapy is still challenging for clinicians. The ultimate goal of root coverage procedures is the complete coverage of the recession defect with an esthetic appearance comparable to adjacent healthy soft tissues in combination with physiological probing pocket depths. Various treatment modalities have been put forth for the correction of gingival recession. These include free gingival autograft, subepithelial connective tissue graft (SCTG), coronally advanced flap (CAF) and various combinations. Coronally advanced flap (CAF) in conjunction with the connective tissue graft (CTG) is considered the gold standard of treatment of gingival recession due to its high predictability of the treatment results. Several authors have explored the use of biological agents or like enamel matrix derivative (EMD), platelet-derived growth factor-BB (PDGF), fibroblast growth factor-2 (FGF-2), which are a group of proteins capable of inducing gene or cell activation for cell recruitment, matrix biosynthesis, and cellular differentiation, in an attempt to regenerate the lost periodontium to enhance its long term stability Hyaluronic acid (HA) is one such biologic agent that demonstrates future for periodontal regeneration. It is a major component of the extracellular matrix in almost all tissues. The primary role of HA is to bind water and to allow the transportation of key metabolites and therefore to maintain the structural and homeostatic integrity of these tissues. HA suppresses tissue breakdown activating metalloproteinase inhibitors. It represents one of the most hygroscopic molecules known in nature. As a physical background material, it functions as space filler, lubricant and a protein excluder as well. In vitro studies and animal studies have demonstrated that HA significantly increases the tensile strength of granulation tissue, stimulates clot formation, induces angiogenesis, increases osteogenesis, and does not interfere in the calcification nodules during bone formation. Furthermore, HA facilitates cell migration and differentiation during tissue formation and repair of both soft and hard tissues. It improves ligament cell viability and early osteogenic differentiation. Considering the fact that HA has positive effects on wound healing, we hypothesized that it may also improve the results of root coverage by CAF+CTG. Therefore, the aim of this randomized controlled clinical trial (RCT) will be to evaluate the potential benefit of the adjunctive use of HA in combination with CAF+CTG and to compare the outcomes with CAF+CTG alone, when treating single Miller class I and class II/RT1gingival recessions.