Application of Optical Coherence Tomography to detect failures at the enamel dental restoration interface— an in vivo study

Summary form only given. Dental restoration interfaces can present failures, known as marginal microleakage. These failures are extremely difficult to diagnose and can develop into recurrent caries if left untreated. The most common tool used for diagnostic imaging in dentistry, X-ray, is not able to visualize micrometric structures. Evaluation of dental restoration in a non-invasive way is a very desirable tool for clinical practice. We present an in vivo study applying Optical Coherence Tomography (OCT) to detect failures at the enamel-dental restoration interface in a clinical setting. OCT is a relatively new but well established imaging technique for diagnosis, that can produce two- or three- dimensional images of bio-tissues with a few mum spatial resolution. We have previously demonstrated the application of OCT for in vitro analysis of dental restoration of enamel. In this work, we report in vivo application of OCT to assess dental restorations. After approval from the Ethical Committee on Human Research at the Universidade Federal de Pernambuco, thirty patients with resin based composite restorations performed in anterior teeth during the period between 2000 and 2007 were selected for examination. These patients, both male and female, between the ages of 18 and 45, were clinically evaluated, and OCT was performed. The results were analyzed with respect to the integrity and marginal adaptation of the restoration. Images were obtained using OCT operating in the spectral domain, with a 840 nm superluminescent diode lightsource (spectral width of 50 nm, fiber output power 25mW and a measured spatial resolution of 10 mum). The image acquisition time was less than one second. The left hand side shows the gingiva, and the right hand side, the enamel. The region within the circle clearly shows the fail in the resin dental composite restoration. Using appropriate software, the lesioned region can be located exactly and a new restoration procedure can be carried out. - In summary, we have shown that OCT is more than adequate in clinical practice to assess dental restorations.