Comparative Evaluation of Gingival Displacement and Patient Outcomes with Different Gingival Retraction Techniques: A Cross-over Clinical Trial

Abstract

Introduction: The success of fixed restorations depends on marginal integrity, particularly in subgingival areas. Gingival retraction facilitates proper placement of impression material in the displaced gingival sulcus; however, a lack of consensus on evaluation criteria hinders comparative studies of gingival retraction systems. Aim: To evaluate the effectiveness of mechanical retraction cord and chemical gingival retraction paste compared to a control group with no retraction. Materials and Methods: This study was a cross-over clinical trial conducted at Saveetha Dental College and Hospitals in Chennai, Tamil Nadu, India, involving 20 patients requiring single crowns from May 2024 and June 2024. Patients were allocated into three groups-no retraction, chemical retraction, and mechanical retraction-based on randomisation. Patients with healthy gingival and periodontal status, exhibiting no bleeding on probing, were included in the study. Impressions were taken at baseline, and subsequent gingival displacements on days 7 and 27 were performed using chemical and mechanical methods according to random allocation. A Visual Analogue Scale (VAS) score was used to analyse post-operative comfort. Gingival displacement was measured with a stereomicroscope, and results were tabulated. Data analyses were performed using Statistical Package for Social Sciences (SPSS) software (version 26.0). Statistical significance was set at a threshold of p chemical retraction > no retraction. For VAS scores, statistically significant results were observed for mechanical retraction compared to no retraction (0.9±0.052) and mechanical retraction (3.40±0.049), as well as between no retraction and chemical retraction (2.6±0.057) (p0.05). Conclusion: Although there was a statistically significant difference in the amount of displacement between the chemical and mechanical systems, both were within the clinically acceptable range (220 microns). Hence, chemical retraction can be used as a substitute for mechanical retraction techniques.

Keywords

• chemical retraction
• gingival sulcus
• mechanical retraction
• stereomicroscope
• vas score