Objective: The objective is to assess existing literature on clinical performance, aesthetic outcome, patient satisfaction and cost-effectiveness of zirconia-based RBBs used to replace missing tooth/teeth in adults and children.
Methods: An electronic search was done following the PRISMA statement for clinical studies on zirconia RBBs published up to December 2011 using MEDLINE/PubMed. The main key search terms were: Zirconia, zirconium, ZrO2, CAD-CAM, computer aided design, computer assisted manufactured, resin*, adhesive*, composite*, bridge*, FPD*, denture*, prostheses*, resin-bonded bridges, Maryland bridge and adhesive bridges. Clinical trials/cohort studies addressing zirconia-based RBBs were considered relevant/included. In vitro studies were excluded. Only one article was found based on these criteria. Case series/reports were then considered for review.
Results: The key search terms yielded 227 articles. Then, abstracts were screened to assess eligibility. Only 7 articles were found relevant. One article is prospective cohort study (level 3 of evidence) and 6 articles are clinical case-reports (level 4 of evidence). The cohort study reported 90% survival rate of RBBs after 22 months and only one failure was reported in the 6 case reports. Patients were satisfied aesthetically and functionally following treatment but the patient satisfaction was reported without a specific measure. The economic aspects of zirconia RBBs were not reported in any of these articles. All of the 7 studies described the excellent aesthetics and function associated with this type of bridges.
Conclusion: In the Literature, there is only one prospective study (level 3 of evidence) and few case reports (level 4 of evidence) available. To obtain level 1 of evidence, long-term controlled clinical trials are needed to confirm the findings of existing literature.