Chemical Retraction Agents – in vivo and in vitro Studies into their Physico-Chemical Properties, Biocompatibility with Gingival Margin Tissues and Compatibility with Elastomer Impression Materials

Abstract

Gingival margin retraction/displacement (GMR/D) is a commonly accepted procedure in restorative dentistry. Of the various retraction methods, the chemo-mechanical approach with retraction media and chemical retraction agents (ChRAs) is mostly used. Different local and/or systemic side effects were observed after "chemical attacks" from these retraction agents. Moreover, no consensus exists as to the compatibility of chemical agents with different impression materials. This paper reports the findings of in vivo and in vitro studies and we discuss the physico-chemical properties of chemical retraction agents, their undesirable clinical side effects, biological activity and compatibility with selected groups of elastomer impression materials.

Effects of Gingival Retraction Paste and Subsequent Cleaning with Hydrogen Peroxide on the Polymerization of Three Elastomeric Impression Materials: An In Vitro Study

“…8 Several studies have investigated the effect of gingival displacement medicaments on the physical properties of impression materials. 1,5,6,[9][10][11][12][13][14][15] Negative effects of ferric subsulfate, ferric sulfate, and aluminum chloride on the polymerization and tear strength of different types of final impression materials have been demonstrated. 9,12 This is possibly due to sulfur that delays or inhibits polymerization.…”

In�vitro effects of vasoconstrictive retraction agents on primary human gingival fibroblasts

“…However, their mechanism of action has not been completely clarified yet. The results presented in the previous studies based on in vitro experiments have expanded the knowledge on the action of vasoconstrictive retraction agents in primary HGFs (1,26,29). Through the assessment of selected oxidative stress markers, such as lipid peroxidation (the concentration of malondialdehyde (MDA)), protein damage (-SH), colony formation, and the expression of manganese superoxide dismutase (MnSOD), it was concluded that the experimental gels induced oxidative changes in primary HGFs at the lowest level.…”

“…Table I shows their characteristics. These chemicals were diluted with Dulbecco's modified Eagle's medium (DMEM) to 1:20 ratio, which was further studied based on our previous studies (1,25).…”

“…Temporary changes in the architecture of the free gingival margin, as well as the gingival crevicular fluid flow and the control of bleeding effect into gingival sulcus, are necessary for the precise treatment procedures in restorative dentistry. Past several decades have witnessed the use of chemo-mechanical methods with various retraction/displacement media and chemical retraction/displacement agents by dentists (1). This technique provides optimal conditions for imaging and transmission of morphological status of the prepared tooth and/or design of the implant's structure and the surrounding periodontal configuration to the dental laboratory through impression materials or optical/digital scanning in the patient's mouth in the computer-aided design/computer-aided manufacturing (CAD/CAM) techniques (2).…”

The Direct Cytotoxic Effects of Different Hemostatic Agents on Human Gingival Fibroblasts

“…Healthy gingival epithelial cells and epithelial attachment constitute a natural physical barrier protecting the connective tissues and minimizing the level of damage. Additionally, the aggressive clinical action of chemical hemostatic agents may be less intense because their concentration is diluted by either natural gingival fluids, saliva, or water spray . However, the findings of the present in vitro study suggest that the risk of tissue damage is high with the use of hemostatic agents such as Astringedent, Hemox‐A, Hemodent, Vicostat, and 3M ESPE Astringent Retraction Paste.…”