Figure 4.

(a)–(x) SEM pictures of different abutment screws: each line of this figure shows SEM pictures of four different screws for a specific implant type. The first picture in each line shows a new unused screw, the second picture shows a screw after using tightening method A, the third picture shows a screw after using tightening method B, and the last picture shows a screw after using tightening method C. Red arrow indicates debris, yellow arrow indicates peeling, green arrow indicates scratch, and blue box indicates screw thread where screw material has peeled off.