Conventional diagnostic methods
frequently detect only late stage enamel demineralization under
composite resin restorations. The objective of this study is to examine
the subsurface tooth–composite interface and to assess for the presence
of secondary caries in pediatric patients using a novel Optical
Coherence Tomography System with an intraoral probe.
newly designed intraoral cross polarization swept source optical
coherence tomography (CP-OCT) imaging system was used to examine the
integrity of the enamel–composite interfaces in vivo. Twenty-two
pediatric subjects were recruited with either recently placed or long
standing composite restorations in their primary teeth. To better
understand how bacterial biofilms cause demineralization at the
interface, we also used the intraoral CP-OCT system to assess ex vivo bacterial biofilm growth on dental composites.
As a positive control, cavitated secondary carious interfaces showed a 18.2dB increase (p<0.001),
or over 1–2 orders of magnitude higher, scattering than interfaces
associated with recently placed composite restorations. Several long
standing composite restorations, which appeared clinically sound, had a
marked increase in scattering than recently placed restorations. This
suggests the ability of CP-OCT to assess interfacial degradation such as
early secondary caries prior to cavitation. CP-OCT was also able to
image ex vivo biofilms on dental composites and assess their thickness.
paper shows that CP-OCT imaging using a beam splitter based design can
examine the subsurface interface of dental composites in human subjects.
Furthermore, the probe dimensions and acquisition speed of the CP-OCT
system allowed for analysis of caries development in children.