Maintenance

2.8.1 Intraoral direct repair of an existing restoration

2.8.2 Maintaining an existing restoration

2.8.3 CAD/CAM-fabricated Michigan splint

2.8.1 Intraoral direct repair of an existing restoration

■ Direct, intraoral composite repair

The following case involves the direct repair of a ceramic chipping on a restored lateral incisor by means of direct composite.

Assessment and treatment options

A 72-year-old woman presented herself at the clinic with the fractured incisal edge of her more than 10-year-old porcelain-fused-to-metal restoration with the wish to repair the fractured Part (Fig 2-8-1). As fractures of the veneering ceramic, especially on implants, are the predominant technical complication, it is an unfortunate issue associated with conventional veneered restorations that cannot be entirely prevented. Looking closer into her case, the chipping occurred in a cantilever four-unit screw-retained implant FDP. Therefore, it would have been quite easy to unscrew the FDP and send it back to the dental laboratory for repair. However, on discussing the patient’s situation with the dental technician, several obstacles came up and had to be taken into consideration.

As the restoration was quite old, it is always a risk to put it back into a ceramic oven, even with the application of a careful pre-drying process. Another issue was that it was unclear which ceramic was used by the dental technician. Therefore the attempt to improve the situation could have actually made the situation even worse for the patient. Still, there was the option to take the restoration out of the mouth, send it to the dental laboratory, and have the laboratory technician in dry conditions make the repair by means of direct composite.

The patient unfortunately did not have any provisional and taking out the restoration, sending it to the laboratory, and screwing it back in would have left the patient without teeth for a minimum of one day and raised the costs; therefore, it was decided to do a direct intraoral repair of the incisal edge by means of a composite build-up.

Direct composite build-up

Once all options had been discussed and evaluated with the patient, the existing restorations was prepared for an intraoral composite build-up of the fractured incisal edge. To achieve dry conditions, rubber dam was placed and the sharp edges of the ceramic fracture line were smoothed. This smoothing has two advantages as it makes the application and the wettability of the surface easier, and then it refreshes the ceramic surface.

Once the restoration was smoothed it could be prepared for the adhesive application of composite. Under the seal of rubber dam the existing intraoral restoration could be safely etched for 1 min with hydrofluoric acid (9% concentration) (Porcelain Etch, Ultradent, Cologne, Germany) and a silane (Monobond Plus, Ivoclar Vivadent) and a bonding system (Heliobond, Ivoclar Vivadent) was applied and light cured (Fig 2-8-2).

The composite build-up (Tetric Classic Dentin and Enamel, Ivoclar Vivadent, Schaan, Liechtenstein) was applied directly and shaped with a spatula. In larger repairs they can be also guided by silicone keys that reflect a wax-up, fabricated by the technician to make the build-up not only more efficient but also extremely predictable.

Once the composite was applied and light-cured, it was polished with disks (Soflex, 3M, Seefeld, Germany) and silicone polishing flames (Optrafine polishing kit, Ivoclar Vivadent). Thereafter the entire restoration and the composite repair were polished to a high gloss with a rotating brush and diamond polishing paste (Optrafine polishing kit, Ivoclar Vivadent) (Fig 2-8-3).

Finally, the functional aspects were checked and lateral contacts removed from occlusion to prevent the repair from chipping in the same way as the initial ceramic (Fig 2-8-4).

As additional information for the patients considering this kind of direct repair, the survival rates after 3 years are at a good 89%1. If they fail, they tend to fail immediately after the treatment in the first 1 to 3 weeks.