GUM RETRACTION METHODS IN ORTHOPEDIC DENTISTRY: CURRENT STATE OF THE PROBLEM

Gingival retraction is the procedure of bending the gingival margin away from the tooth surface, which provides sufficient horizontal and vertical space between the prepared finish line and the gingiva for the introduction of a sufficient amount of impression material. Several factors influence the success and durability of orthopedic restorations in dentistry. In particular, supragingival margins are necessary to maintain periodontal health, but do not provide optimal aesthetics. The gingival margin should be clean and accessible during impression making, and the gingival groove should be wide enough (from 0.15 to 0.20 mm). Therefore, in orthopedic dentistry, the problem of the optimal gum retraction technique, the influence of the chosen technique on the impression procedure is relevant. Ideally, the gum retraction technique should be simple, fast and inexpensive, should not cause damage to the periodontal tissues. Today, there are various methods of retraction, including retraction cords, rotary curettage, copper tapes, electrosurgical techniques, laser retraction, and the use of some types of polymer and plastic materials. The article provides an overview of the main commonly accepted methods of gum retraction, which can be classified into mechanical, chemical and surgical. Particular attention is paid to such retraction methods as non-medicated cords, medicated cords, wireless methods, astringent hemostatic agents, retraction paste for gums, vasoconstrictors, lasers, rotary curettage, electrosurgery. Study substantiation: Despite significant progress of orthopedic dentistry in the last decades, clear criteria for selection of method of retraction are not currently allocated. The purpose of the study: to conduct an analysis of modern and available methods of gum retraction in orthopedic dentistry, to highlight the safety and effectiveness criteria of each of the methods, depending on the clinical situation. The materials and methods: the available scientific sources of recent years, devoted to the technique of gum retraction in orthopedic dentistry, analyzed by the methods of review, system and content analysis. The search strategy was to manually search the Pub-Med and Google Scholar databases from 1985 to 2022 for articles related to retraction prior to making an impression of a fixed prosthesis. Key words included "impression making" and "gingival retraction". The clinical effectiveness of retraction methods is assessed according to the following criteria: A – effectiveness (degree of horizontal and vertical gum recession, possibility of controlling bleeding and outflow of gum fluid). B – degree of retraction (ideally, the agents used should not lead to damage to the epithelial tissue). Otherwise, this damage should be reversible. The maximum apical recession after gingival retraction should not exceed 0.10 mm. C-absorption of retraction agents in tissue should not cause systemic effects. The conclusion of the review is a general assessment of the effectiveness of retraction methods according to the following criteria: effectiveness, degree of retraction, absorption of retraction agents. Emphasis is placed on the greatest efficiency of the laser retraction method. The author suggests further research in this direction. Despite the significant progress of orthopedic dentistry in recent decades, additional research should be conducted to develop clear criteria for the effectiveness of gum retraction methods.