Parallel Pins
After use of 2.2 mm IS drill, DIO parallel pins are unstable at #2 and 3, partially due to shallow osteotomy. PA is not taken with parallel pins. When dummy implants are placed, the axis at #3 is noted; but instead of moving the apical end of the osteotomy distal (Fig.1 red line), the coronal end is moved mesial. By the time definitive implants and abutments are placed, the axis of #3 is parallel to that of #4, but close to each other (Fig.2,3). Orthogonal panoramic X-ray shows that they are critically close (Fig.4). If PA were taken with parallel pins after initial osteotomy, correction would be easy. The patient is doing fine postop without pain or nasal hemorrhage. There is no thread exposure 11 months postop (Fig.5). The abutment screw at #3 is retightened 7.5 months post cementation (Fig.6 (poor crown/implant ratio)).
Return to Upper Molar Immediate Implant, Prevent Molar Periimplantitis (Protocols, Table), Armaments Screw
Xin Wei, DDS, PhD, MS 1st edition 04/24/2018, last revision 01/03/2020