Two Year Clinical Evaluation of Zirconia Bridges

Objective:

To evaluate the 24 month clinical performance of Y-TZP CAD/CAM generated ceramic system in fixed prosthodontics.

Methods:

Sixteen bridges (15 three- and 1 four-unit) were done on 15 subjects. The bridges were cemented using RelyXTM Unicem™ Self-Adhesive Universal Resin Cement. Evaluation was done at 6,12,24- months recall visits. Evaluation criteria were Color stability and matching, Marginal integrity, Marginal discoloration, Incidence of caries, Changes in the restoration-tooth interface, Changes in surface texture, Postoperative sensitivity, Maintenance of periodontal health, Changes in proximal and opposing teeth and Maintenance of anatomic form. The bridges were rated in one of three possible categories, “A” (alpha), “B” (bravo) or “C” (Charlie) 

Results:                                                                     

 At 6-,12, 24 month recalls 100% of the bridges were rated “A” for Color Stability & Matching, Marginal Discoloration, Marginal Integrity (24 month recall 93.75% “A” and 6.25 % “B” ), Incidence of Caries, Restoration-tooth-interface, Surface Texture & Changes in Proximal or Opposing Teeth.

Maintenance of Anatomic Form was rated “A” in 100% of the bridges at 6-month recall but at 12 month  93.75% of the bridges were rated “A” and 6.25% were rated “C” . At the 24 month recall 87.5 % of the bridges were rated “A” and 12.5% were rated “C” .

 Post Operative Sensitivity was rated “A” for 93.75% of the bridges at 6, 12, & 100% at 24 months.                                                                                           

 Soft Tissue Health was rated “A”  in 81.25% of the bridges and “B” in 18.75% of the bridges  at 6-month recall but at 12 and 24 month recalls, 68.75% and 93.75% of the bridges were rated “A” and 31.25% and 6.25% were rated “B” respectively.           

Conclusion: After 24 months, 12.50% (2 out of 16) was unacceptable due to failure in maintenance of anatomic form. The CAD/CAM Generated Y-TZP bridges were clinically acceptable. (Study supported in part by 3M ESPE)