<s>[INST] context: The ovate pontic is the pontic design that is most esthetically appealing. Its convex tissue surface resides in a soft tissue depression or hollow in the residual ridge, which makes it appear that a tooth is literally emerging from the gingiva. 
Careful treatment planning is necessary for successful results. Socket-preservation techniques should be performed at the time of extraction to create the tissue recess from which the ovate pontic form will appear to emerge. 
For a preexisting residual ridge, surgical augmentation of the soft tissue is typically required. When an adequate volume of ridge tissue is established, a socket depression is sculpted into the ridge with surgical diamonds, electrosurgery, or a dental laser.

Key Concept:
For a preexisting residual ridge, surgical augmentation of the soft tissue is typically required. When an adequate volume of ridge tissue is established, a socket depression is sculpted into the ridge with surgical diamonds, electrosurgery, or a dental laser. [/INST] question: Which of the following pontic designs require surgical procedure? | options: A: Modified ridge lap B: Saddle C: Ovate D: Sanitary | answer: C </s>