Introduction

Dental implants have been a life-enhancing modality for partially and completely edentulous patients. Implants can successfully support a cemented or screw-retained single crown. However, this modality is not without complications: A fractured abutment screw may occur when the prosthesis is under functional cyclic loading. The abutment screw may be overloaded and fracture, leaving the abutment and coronal screw fragment inside the abutment/crown and the apical fragment in the fixture itself.

Abutment screw fracture is a rare event, occurring less than 0.5%. Nonetheless, when a fracture occurs, it is very disturbing for the clinician.

Occlusal loading is a multidirectional and variable magnitude force. Even though an integrated implant transmits the load to the surrounding bone, the load is transmitted through the abutment and its retaining screw. There is a slight wobble of the abutment during functional loads. The abutment screw will receive tensile and bending movements that can induce a fatigue fracture. The crown will generally dislodge, and the apical end of the screw will remain in the fixture. This needs to be removed so that a new screw can be placed and the crown occlusally adjusted to preclude a repeat fracture.

There are several techniques for managing a fractured abutment screw. These include implant removal and retreatment, fabrication of a cemented cast post and core, screw fragment retrieval, and other techniques.

Many (but not all) implant companies offer fracture screw removal kits, but they are expensive and do not consistently remove the fracture segment. The technique presented herein has been used for many years by this author with consistent results, and it salvages the crown as well. This complete technique has never before been reported in the literature. Since these are case reports and not a randomized controlled trial, this is low credibility evidence.

Case reports and a technique for abutment, fragment retrieval, and crown-abutment separation and crown recementation and overdenture retainer fracture are discussed herein.