Clinical Advantages of Angled Screw Access Channels for Implant-Supported Restorations in the Esthetic Zone.

Abstract

Introduction: Retained cement following delivery of an implant-supported crown is strongly associated with peri-implant mucositis and peri-implantitis, and screw retention is a strategy for avoiding this problem entirely. In the esthetic zone, screw retention compromises esthetics unless the screw access in the crown is concealed to the palatal of the incisal edge. To avoid positioning the implant platform excessively toward the palate, practitioners can design an angled screw access channel in the crown.

Case presentation: A healthy 22-year-old patient with nonrestorable tooth #9 received extraction and immediate implant placement with immediate provisionalization. The screw access channel for the provisional restoration involved the incisal edge. Rather than placing a custom abutment and cementing the definitive restoration, an angled screw access channel was employed. The implant-supported restoration exhibited favorable esthetics, and the possibility of retained cement was avoided.

Conclusion: Up to a point, positioning maxillary anterior implants toward the palate is favorable. When the long axis of the implant is directed between the incisal edge and the cingulum of adjacent teeth, the implantsupported crown can be screw retained without compromising esthetics. In immediate implant situations, such positioning also increases the distance between the implant and the facial alveolar bone and encourages a favorable position of the marginal peri-implant mucosa. However, an excessively palatal platform position compels a restoration with irregular contours, which can frustrate proper oral hygiene and professional maintenance. Angled screw access channels allow screw retention without excessive palatal positioning of the platform, avoiding the possibility of cement-related peri-implant disease.