In 2004, the patient, a smoker, began dental treatment at the ACTA graduate clinic. She was a TV producer exposed to a lot of stress in her job and had a sick husband. Her maxillary teeth had been extracted, as had the mandibular canines, premolars, and molars, with the exception of tooth 34.
She received a complete maxillary denture and a mandibular skeleton denture. In October 2007, her maxilla was augmented by an oral and maxillofacial surgeon; in March 2008, implants (Biomet 3i, Palm Beach, Florida, USA) were inserted at that same clinic.
In 2008, the patient was presented at the Department of Oral Implantology and Prosthetic Dentistry to request restorations for her implants. An implant-supported overdenture was planned. She also asked if we could restore her occlusion with fixed prosthetics. To that end, we inserted four mandibular implants (35, 44: Straumann SP, diameter 4.1 mm, length 10 mm; 36, 46: Straumann SPWN, diameter 4.8 mm, length 10 mm; Institut Straumann AG, Basel, Switzerland) and fit these with a three-unit fixed partial denture and two single crowns.
The mandibular implants were inserted at the ACTA postgraduate implant clinic in August 2008. To prepare for the prosthetic phase and to evaluate the augmentation of the maxilla, the second-stage surgery was carried out by the oral and maxillofacial surgeon. In October 2008, the patient reported pain and irritation around the healing caps in the maxilla. The soft tissue around the healing caps had begun to show symptoms of inflammation (Fig 1a). The soft tissue was resected but the inflammation and proliferation returned (Fig 1b). The patient had also started to develop signs and symptoms of an allergy. Her hands and face developed skin problems (Figs 2a-b).
We replaced the healing caps with titanium healing caps (Figs 3a-b). One week later, the problems had disappeared. Differential diagnosis pointed to hypersensitivity to the metal of the healing caps. The material was examined by our material sciences department.
Several samples were taken of the healing abutments using an Arkansas stone and analyzed by energy-dispersive X-ray spectroscopy (EDX). The analysis showed that the healing caps contained palladium. A superstructure (Fig 4) and a resin-based denture (Figs 5a-b) were inserted. The mandibular implants were restored with metal-ceramic crowns and a bridge.
Table 1 ADX analysis, new restorations (% w/w).
|
Au |
Pt |
Cu |
Zn |
Ag |
Pd |
Cr |
Mo |
Co |
|
|
Superstructure |
86 |
11 |
2 |
1 |
|||||
|
Clips |
68 |
4 |
12 |
3 |
10 |
3 |
|||
|
Maxillary denture, metal part |
28 |
10 |
62 |
||||||
|
Metal-ceramic crown 35 |
96 |
1 |
2 |
2 |
|||||
|
Metal-ceramic crown 36 |
84 |
11 |
1 |
2 |
|||||
|
Metal-ceramic crowns 45/46 |
83 |
14 |
2 |
1 |
After the maxillary superstructure, the mandibular crowns, and the overdenture had been inserted, some irritation reoccurred in the maxilla. We analyzed the materials used in the dental restorations and found that the clips used in the overdenture contained a small amount of palladium. Once the clips were removed and replaced with a nickel-free and palladium-free alloy, the complaints disappeared.
Discussion
The anamnesis of this patient contained several “red flags.” She reported being allergic to adhesive bandages, plastic watch straps, some brands of deodorant, bell pepper, nickel, and other metals but not to silver and gold. She also wore an intrauterine contraceptive device made of copper, to which she reported no allergic reactions; she did report additional allergies to ammonia and several brands of detergents.
Given the patient’s known allergy to nickel, we considered this the probable explanation for her specific reaction when exchanged the primary healing caps for titanium caps. On the other hand, it would seem advisable for a patient with multiple signs of allergy to undergo comprehensive allergy testing. It was not until after specific allergy testing that we discovered her hypersensitivity to palladium and found that the initial healing caps had also contained palladium.