Table 3.

Scoring system for resistance-to-removal (RTR) and attached bone remnants (ABR)

Score	RTR	ABR
1	Loose screw can be removed with forceps only	No bone detectable on implant
2	Little resistance (only tip of 2 fingers needed to hold screwdriver)	Traces of bone remnants on implant
3	Moderate resistance (screwdriver held in pinch grip)	Thin bone layer on implant (10–25 % of surface coated with bone)
4	Strong resistance (like 3 but more power needed)	Moderate bone layer on implant (25–50 % of surface coated with bone)
5	Bone fracture with screw partly covered by bone	Thick bone layer on implant (>50 % of surface coated with bone)