Keeping implant screws tight: the solution.

Retrievability is the major advantage of screw-retained implant restorations compared to cement retention; however, implant screw loosening continues to be a frequently cited disadvantage of this technique. This paper describes the factors involved in maintaining a stable screw joint assembly by maximizing preload on the retaining screw while minimizing joint-separating forces. Practical clinical solutions to minimize this clinical problem are suggested. Readers are cautioned to address both the occlusal and biomechanical etiologies of screw loosening.