#12 DO Ag Preparation
Occlusal Measurements
Isthmus Width: 1.0 - 1.2 mm
- RGS 3 Width (W) 
Dovetail Extensions: 0.25 - 0.5 mm
- RGS 1 (W) 
Box Measurements
Exit Angle: 90 degrees
Proximal Wall Clearance: 0.5 mm (0.4 - 0.75 mm)
- RGS 1 W or Explorer Tip 
Proximal Wall angle: 90 degrees to slightly < 90 degrees
Gingival Wall Clearance: 0.5 mm
- RGS 1 W or Explorer Tip 
Axial Depth: 1.0 - 1.5 mm
- RGS3/4 W 
Retention Groove Depth: 0.25 mm depth
Other Features
* S-curve as needed to connect the proximal box to the isthmus
* Convergent proximal walls
* Rounded axiopulpal line angle


 
            