Final answer:
The less commonly used surgical blade in surgical perio procedures is the 3-blade design, according to Figure 12.4. This design is considered efficient and has a lower tip speed, reducing the risk of accidents.
Step-by-step explanation:
In surgical periodontal procedures, the less commonly used surgical blade is the 3-blade design. According to Figure 12.4, this design is the most efficient, but its lower tip speed is less dangerous compared to 2 or 1-blade designs. The 3-blade design is not as commonly used because it may not be necessary in all surgical perioprocedures.