Assessing ex vivo dental biofilms and in vivo composite restorations using cross-polarization optical coherence tomography

A cross-polarization 1310-nm optical coherence tomography system (CP-OCT), using a beam splitter based design, was used to assess ex vivo growth of complex multi-species dental biofilms. These biofilm microcosms were derived from plaque samples along the interface of composite or amalgam restoration in children with a history of early childhood caries. This paper presents a method of measuring the mean biofilm height of mature biofilms using CP-OCT. For our in vivo application, the novel swept source based CP-OCT intraoral probe (Santec Co. Komaki, Japan) dimensions and system image acquisition speed (20 image frames/second) allowed imaging pediatric subjects as young as 4 years old. The subsurface enamel under the interface of composite resin restorations of pediatric subjects were imaged using CP-OCT. Cavitated secondary caries is clearly evident from sound resin composite restorations.