Chiyun Won  Academic Committee – Oral Surgery Division (A Novel Framework for Optimizing Peri-Implant Soft Tissue in Subcrestally Placed Implants in Single Molar Cases: Integrating Transitional and Subcrestal Zones for Biological Stability)

https://www.mdpi.com/2077-0383/14/7/2435

Purpose: To systematize the understanding of soft tissue adaptation in subcrestal implant placement.

Main Concepts:
1. Introduction of Transitional Zone (TZ) and Subcrestal Zone (SZ): Integrating these two zones led to the concept of Self-Sustained Soft Tissue (SSST).
2. Mathematical Modeling: Developed a model incorporating emergence angle (EA), soft tissue thickness (STT), and peripheral crestal offset (PCO) to calculate optimal implant depth.
3. 3D Soft Tissue Analysis (3DSTA): CBCT-based 3D visualization of peri-implant soft tissue structure.
4. Validation of SSST: Clinical and visual evidence confirmed that TZ and SZ can maintain soft tissue stability without traditional epithelial coverage.

Conclusions & Clinical Implications: The SSST concept extends the conventional “biologic width,” providing a new biological foundation for peri-implant tissue stability. Offers practical guidelines for designing emergence profiles and determining implant depth to enhance soft tissue integration.