
Comparative Evaluation of Gingival Displacement and Patient Outcomes with Different Gingival Retraction Techniques: A Cross-over Clinical Trial
ZC64-ZC68
Correspondence
Amrutha Shenoy,
Assistant Professor, Department of Prosthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai-600077, Tamil Nadu, India.
E-mail: amruthashenoyd.sdc@saveetha.com
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<0.05, employing one-way analysis of variance and Tukey post-hoc tests for gingival retraction and Visual Analog Scale (VAS) scores.
Results: Among the 60 tested samples, significant differences in gingival retraction were noted (p<0.05). Both experimental groups (Mechanical gingival retraction=698.53±43.276 μm, Chemical retraction=509.33±29.405 μm) exhibited more gingival displacement than the control group (mean gingival retraction=164.8±15.725 μm), with mechanical retraction cord displaying the highest value. The mean gingival displacement rankings were as follows: mechanical retraction > 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) (p<0.05). However, the differences between mechanical and chemical retraction were not statistically significant (p>0.05).
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.