A 51-year-old female came to the Dental Clinic of the National Research Centre, complaining of complete detachment of her implant—supported FPD from their respective implants in the maxillary right first premolar-molar area and holding the abutment with the cemented FPD restoration as one unit in her hand (Fig. 1).
First, the patient signed a written informed consent before sharing in this case report, and then, a thorough medical and dental history was taken during which the patient revealed that the implants were placed 4 years ago. The patient also denied having any parafunctional habits such as bruxism or clenching.
Clinical examination
Visual examination revealed two improperly aligned implants in the premolar-molar area (Fig. 2). And clinical examination demonstrated absence of tenderness or inflammations in the surrounding gingiva or the soft tissues, and no implant mobility was detected.
Diagnostic assessment
Periapical radiograph was made to assess the bone support, examine the implant body, and detect any fracture.
Intervention
The implant’s internal connection was inspected for possible food debris impaction and was irrigated using a plastic syringe filled by 0.12% chlorohexidine mouthwash (Hekma Pharma, Egypt). A decision was taken to retrieve the abutments’ screw connections from the FPD using 5% acetic acid (vinegar) (sugar cane Wadi Food, Wadi Food Industries Co., Egypt) rather than perforation of restoration to locate the screw access to enable re-cementation of the FPD restoration Fig. 3.
To debond the cemented FPD from the abutments, the FPD was suspended in undiluted vinegar for 24 h in such a way that only one abutment was completely immersed one at a time. The pH value of the acetic acid was measured using a pH meter (Hanna Instrument, Romania, Model H12550) and the pH was 2.
After debonding and complete separation of the first abutment from the restoration, the same procedure was repeated for the other abutment.
Residual soft cement was carefully removed from the restoration and the abutment using an excavator.
The retrieved abutments were then placed on the implants, and a periapical radiograph was taken to confirm the correct seating of the abutments to the implant platforms. Tightening of the abutments was done using a wrench torque to 35 N, and the screw access hole was filled with cotton pellets and a cold cured resin material (Acrostone, WHW Plastic, England, packed by Anglo Egyptian Lab).
The FPD restoration was cemented using zinc oxide non-eugenol cement (3M ESPE; Germany) Fig. 4. Excess cement was carefully removed, and a final periapical radiograph was taken to verify the absence of excess luting cement. The occlusion was checked using articulating paper (Horseshoe, USA) to detect any occlusal interferences, and the patient was scheduled for recall appointments.