Restoring severely angled implants with custom abutments and a screw-retained fixed dental prosthesis

In the last four decades, dental implants enhanced quality of life for millions of patients.^1,2 As the treatment became more predictable, the benefits of therapy became evident.^1,2 The huge demand for implants has caused a rapid expansion of the market.² Although many studies regarding dental implants have indicated promising outcomes,¹ some challenges have been reported due to operator related and patient related factors.^3,4 Anatomic challenges may cause less than ideal implant placement if major bone grafting procedures can not be performed.⁵ Implants can be placed with inclinations and angled/custom abutments can be used to overcome the difficulty.⁵ This clinical report is aimed to demonstrate how to restore six misaligned implants in the maxilla by using a fixed dental prosthesis.

A 46-year-old woman with 6 maxillary implants placed in another practice about five months ago came to our clinic for restoration. Her dentist refused to restore her maxilla due to existing angulation of the implants. In our clinical examination, it was observed that six maxillary implants were placed with severe buccal inclinations. All implants were stable. Our treatment plan prosthodontic treatment included custom abutments, two metal superstructures, and a screw-retained fixed dental prosthesis.

Our restorative treatment began with preliminary impressions made with irreversible hydrocolloid impression material Then, a maxillary implant-level final impression was made with a custom tray, impression copings and polyvinyl siloxane impression material to make a definitive cast including implant replicas. A maxilla–mandibular relationship record was made with a polyvinyl siloxane occlusal registration material. Then, both casts were mounted on a semi-adjustable articulator by using a facebow record. After tooth arrangement was completed, the trial denture was inserted and the patient's approval was obtained. An index of the teeth using a silicone putty to cover the labial surfaces of the teeth from the incisal edges down to the indexed land area of the cast was made. Then, a wax pattern of the screw-retained framework was made and cast according to the position of the teeth on the index. The fit of the framework was verified in the clinic (Fig. 1A and B). The denture teeth were transferred from the tooth index to the framework via the previously made tooth index. The second trial denture insertion was performed to verify centric occlusion, esthetics, phonetics, and occlusal vertical dimension. After approval by the patient, the maxillary restoration was processed, finished, and polished in the laboratory (Fig. 1C and D). The metal bars with abutments were seated intraorally and torqued with 35Ncm. Occlusal adjustments were made, and then it was finished and polished. All retaining screws of the maxillary fixed dental prosthesis were screwed on the metal bars and torqued to 20Ncm. The screw access holes were covered with cotton pellets and composite restoration material (Fig. 1E and F). The patient did not report any problems with the implants and restoration during the first year of service.

Figure 1.

Intra-oral view of the metal bars connecting implants (A). Occlusal view of the maxillary framework (B). Occlusal view (C), and intaglio surface (D) of the maxillary prosthesis. Intra-oral view of the maxillary screw-retained fixed dental prosthesis (E). Panoramic radiograph of implants and restoration 6 months after implant placement (F).

This clinical report described how to manage a challenging case due to misaligned implants. The technique described in this report may be a feasible way to efficiently restore misaligned implants.

Conflicts of interest statement

The author has no conflicts of interest relevant to this article.