Evaluation of Gingival Displacement Methods

This study was designed to compare four different gingival displacement techniques in terms of their effectiveness in achieving both vertical and horizontal gingival retraction. The aim was to evaluate the extent of gingival tissue displacement and the associated clinical outcomes, such as bleeding, for each intervention, thereby helping clinicians select the most appropriate method in various clinical scenarios.

Systemically healthy individuals over 18 years of age requiring fixed prosthodontic treatment with abutment teeth in the canine, premolar, or molar regions were included in this study. Fifty-two teeth were randomly assigned to four groups (n=13) and prepared with an epigingival margin and chamfer finish line.

Group K: 15% ferric sulfate-impregnated retraction cord Group P1: Retraction paste in capsule form containing 15% aluminum chloride Group P2: Retraction paste in injector form containing 15% aluminum chloride with a compression cap Group L: 810-nm diode laser All teeth were prepared with an epigingival margin and chamfer finish line to standardize clinical conditions. Gingival displacement was evaluated in two dimensions: Vertical displacement was measured using a periodontal probe before and one week after gingival displacement. Horizontal displacement was assessed by taking polyvinyl siloxane impressions at the same time points. These impressions were analyzed under a stereomicroscope, and displacement was quantified using calibrated image analysis software.

Each intervention was applied following standardized protocols: In Groups K, P1, and P2, materials were applied for 3 minutes. In Group L, the diode laser was used in contact mode to ablate the sulcular epithelium using specific pulse and power settings (1.0 W, 1 ms pulse length). In addition to displacement measurements, post-displacement hemorrhage was clinically evaluated as a secondary outcome to assess tissue trauma and hemostatic effectiveness. All clinical procedures and measurements were performed by the same calibrated operator to ensure consistency.

Statistical analysis was conducted using SPSS software. The distribution of data was tested with the Shapiro-Wilk test. Inter-group comparisons were analyzed with the Kruskal-Wallis and Dunn's post hoc tests; intra-group comparisons used paired t-tests or Wilcoxon Signed Rank tests, depending on data distribution. A p-value < 0.05 was considered statistically significant.

The results are intended to guide clinicians in selecting gingival displacement techniques based on quantitative performance and clinical behavior under standardized conditions.

Inclusion criteria

• Being over 18 years of age
• Having clinically and radiographically healthy periodontal tissues (probing depth not exceeding 3 mm, no bleeding on probing, no gingival recession, no bone loss)
• Having completed Phase I periodontal therapy
• Having no systemic disease that could affect periodontal health
• Having abutment teeth located in the canine, premolar, or molar regions
• Absence of any developmental anomalies in the abutment teeth
• Absence of age-related degenerative changes in the abutment teeth

Exclusion criteria

• Being under 18 years of age
• Having an uncontrolled or periodontal-health-affecting systemic disease
• Not having periodontally healthy tissues
• Having adjacent abutment teeth
• Having previously prepared abutment teeth
• Presence of any developmental anomaly in the abutment teeth
• Presence of age-related degenerative changes in the abutment teeth