The main objective of the present prospective study is to evaluate the effectiveness of posterior zirconia FDPs after 14 years of function.

thirty-seven patients needing to replace either premolars or molars were involved and 48 3-unit zirconia-based FDPs were fabricated. Patients included in the present clinical study met specific inclusion criteria and clinical procedures were standardized.

Frameworks with a 9 mm2 cross section of the connectors and 0.6 mm minimum thickness of the retainers were made by means of Computer Aided Design/Computer Assisted Manufacturing. A resin cement was used to lute the restorations. The patients were recalled after 6 and 12 months and then yearly up to a total follow-up of 14 years. The United States Public Health Service criteria were used in order to examine technical and esthetic outcomes. Success and survival rates

Inclusion Criteria:

• good general health;
• ASA I or ASA II according to the American Society of Anesthesiologists;
• good periodontal health;
• Angle class I occlusal relationship;
• minimum of 20 teeth;
• good oral hygiene;
• no evident signs of occlusal parafunctions and/or temporo-mandibular disorders.

Moreover, the abutment teeth had to fulfill the following inclusion criteria:

• periodontal health (absence of tooth mobility, absence of furcation involvement);
• proper positioning in the dental arch (tooth axes adequate for a FDP);
• sufficient occlusal-cervical height of the clinical crown (≥4 mm) for the retention of a FDP;
• vital or endodontically treated to a clinically sound state;
• opposing natural teeth or fixed prostheses.

Exclusion Criteria:- subjects preferring implant-supported prostheses;

• high caries activity;
• occlusal-gingival height of the abutment teeth <4 mm;
• reduced interocclusal distance or supraerupted opposing teeth;
• unfavorable crown-to-root ratio;
• severe wear facets, clenching, bruxism;
• presence of removable partial dentures;
• pregnancy or lactation.

In the present prospective clinical study, 37 patients (16 males, 21 females) needing at least 1 posterior FDP in the maxillary and/or the mandibular arches were recruited. The mean age of patients was 45.3 ± 11.6 years, with a minimum age of 21 and a maximum of 68 years. All patients were recruited at the Department of Prosthodontics of the University "Federico II" of Naples (Italy) from November 2004 to April 2005 (baseline) and provided a written informed consent