Implant-supported Fixed Dental Prostheses (FDPs) With Cantilever Extension

Patients with full ceramic FDPCs in anterior and posterior areas will be clinically and radiographically re-evaluated. Mesial and distal radiographic marginal bone levels (mBLs) from baseline (i.e. delivery of FDPC) to the follow-up examination were calculated and compared between implant surfaces adjacent to and distant from the cantilever extension. Implant survival rate (%), pocket probing depth (PPD), presence/ absence of bleeding on probing (BoP) and presence/absence of mechanical/technical and biological complications were recorded.

Inclusion criteria

• Patients aged ≥18 years
• Written informed consent
• Patients with systemic health or controlled medical conditions
• Patients with healthy or treated periodontal conditions
• Patients enrolled in regular supportive periodontal therapy (SPT)
• Patients without clinical signs of bruxism and/or oral parafunctions
• 2 osseointegrated dental implants in the canine or posterior areas of maxilla and mandible following transmucosal placement and healing of 3-6 months
• Tissue level solid-screw implants with a sand-blasted and acid- etched (SLA) surface with an endosseous diameter of 3.3, 4.1 or 4.8 mm, a length of 8, 10 or 12 mm, a shoulder diameter of 4.8 mm and a supracrestal machined neck with a height of 1.8 or 2.8 mm (Straumann® Dental Implant System, Institut Straumann AG, Basel, Switzerland)
• Full-ceramic
• Utilization of prefabricated titanium abutments
• Cemented (3M™ ESPE Ketac™ Cem, Seefeld, Germany) or screw-retained fixed dental prostheses with a mesial or distal cantilever extension (FDPCs)
• Cantilever extension corresponding to 1 premolar unit (i.e., 6-7 mm)
• Absence of occlusal contacts or guidance on the cantilever extension at baseline
• Opposing dentition consisting of natural teeth or fixed or removable prosthetic restorations
• Availability of a periapical radiograph at baseline (i.e. FDPC delivery)
• Availability of PPD measurements (mm) taken at baseline at 4 sites/implant with a graduated Michigan periodontal probe (Deppeler SA, Rolle, Switzerland)
• Availability of BoP measurements (%) (Lang et al., 1986) taken at baseline at 4 sites/implant with a graduated Michigan periodontal probe (Deppeler SA, Rolle, Switzerland).

Exclusion criteria

• Untreated or active periodontal diseases
• Immediate implant placement (i.e., Type I implant placement according to Hämmerle et al., 2004)
• FDPCs in the aesthetic zone (i.e., replacement of maxillary or mandibular incisors)
• FDPCs supported by hollow-screw and hollow-cylinder implants