What is All-on-4?
All-on-4 is an innovative surgical and prosthetic technique for full-arch teeth replacement. The core concept is to support a complete arch of fixed prosthetic teeth (usually a bridge of 12-14 teeth) using only four dental implants as foundations.
It is designed for patients who are edentulous (have no teeth), have severely broken-down teeth, or are extremely dissatisfied with their conventional removable dentures, offering a nearly permanent solution.
II. Technical Principle and Advantages
Biomechanical Ingenuity - Angled Implants:
Traditional implant placement in the back of the mouth is often hindered by significant bone loss or the presence of the maxillary sinus (upper jaw) and inferior alveolar nerve (lower jaw), requiring complex and costly bone grafting.
The key to All-on-4 is the tilting of the two posterior implants at angles of 30 to 45 degrees. This approach offers several benefits:
Avoids Anatomical Structures: Effectively bypasses the sinus and nerve, reducing surgical risks.
Utilizes High-Quality Bone: The angled placement allows engagement with denser bone in the anterior and zygomatic regions, providing superior primary stability.
Enhanced Mechanical Support: Tilting creates a larger "intra-basal support", distributing chewing forces more effectively and creating a stable prosthetic structure.
Efficiency: Compared to traditional full-arch restoration which may require 6, 8, or more implants, All-on-4 reduces surgical complexity and treatment time.