Effect of Three Different Commonly Available Gingival Retraction Systems on the Amount of Gingival Displacement: An In Vivo Study

INTRODUCTION: Accurate recording of finish line margins is essential for the success of fixed prosthodontic restoration. Gingival displacement plays a crucial role in achieving adequate exposure of the subgingival margins, thereby ensuring proper marginal adaptation and long-term periodontal health. Various gingival retraction systems, including conventional cords and newer cordless materials such as pastes and gels, are available; however, their comparative effectiveness remains a topic of clinical interest. This study aimed to evaluate and compare the effectiveness of three commonly used gingival retraction systems in achieving gingival displacement based on pre- and post-retraction measurements. MATERIALS AND METHODS: This prospective observational in vivo study included 15 systemically healthy participants aged 18-25 years old. Gingival displacement was evaluated on the maxillary right central incisor using three retraction systems: retraction cord (n = 15), astringent retraction paste (n = 15), and Racegel (n = 15). The control group (n = 15) had no gingival retraction. Baseline impressions were recorded without retraction, followed by post-retraction impressions after the application of each system under standardized conditions. Thus, each participant underwent four impression procedures, yielding a total of 60 impressions. One impression without gingival retraction served as the control, while three additional impressions were recorded following gingival displacement using the respective retraction systems. Consequently, 15 control impressions and 45 impressions after gingival retraction (15 per system) were obtained. The casts were sectioned and analyzed using a stereomicroscope and ImageJ software (National Institutes of Health (NIH), Bethesda, MD, USA). Horizontal and vertical displacements were measured in micrometers (µm). Statistical analyses were performed using one-way analysis of variance and post-hoc Tukey's tests. RESULTS: The mean horizontal displacement was highest in the retraction cord group (92.289 ± 28.724 µm), followed by Racegel (62.409 ± 21.978 µm) and retraction paste (58.213 ± 18.485 µm), with statistically significant differences among the groups (p < 0.001). Similarly, vertical displacement was greatest with retraction cord (458.530 ± 112.414 µm), followed by retraction paste (416.638 ± 110.911 µm) and Racegel (370.697 ± 68.476 µm), with significant differences (p < 0.001). CONCLUSION: The retraction cord demonstrated superior gingival displacement compared to the cordless systems. However, Racegel and retraction paste provided clinically acceptable results and may be considered alternatives in situations prioritizing patient comfort and minimal tissue trauma.