The Characteristics and Survival Rate of Resin Bonded Bridges (RBBs) Provided by Undergraduate Dental Students

Objectives: The objective of this study was to assess the characteristics and survival rate of RBBs provided by undergraduate dental students at Barts and The London School of Medicine and Dentistry.
Methods: Records of patients with resin bonded bridges from undergraduate clinics in London and Southend (outreach) were retrieved between 2008 and 2013. Data was obtained from patients’ clinical records, telephone interviews and by sending letters to the patients. A total of 55 RBBs in 48 patients were assessed for a period of 5 years retrospectively. There were 26 female and 29 male in this study. These patients were initially referred from their General Dental Practitioners. The reasons for tooth replacement were dental caries, periodontal disease and dental trauma. Time of failure, modes of failure, details of maintenance requirements, design and location of RBBs within the arch, the use of rubber dam, tooth preparation, sandblasting procedure before cementation, type of cement used were recorded for each RBBs retrospectively. All these outcomes were subsequently analysed by the employment of SPSS 22 software. (Significance level of p< 0.05 was used).
Results: A total of 30 RBBs were then analysed for the survival rate (25 patients were uncontactable due to change of address, invalid telephone numbers and death). A total of 48 RBBs had cantilever design whilst 7 had fixed-fixed design. 12 of 30 restorations failed to survive between 2008 and 2013. The success rate of RBBs provided by undergraduate students was 56.6% after 5 years. The main failure mode was debonding.
Conclusions: The success rate of RBBs obtained from this data was relatively lower in comparison to 87.7% of an estimated survival rate for RBBs after 5 years suggested by Pjetursson et al., 2008. Debonding is one of the main failure modes.

Long-term data with larger sample size and patient related outcomes are required.