Bioresorbable Nanoparticles for Visual Detection of Early-Stage Dental Caries - PROJECT SUMMARY/ABSTRACT
This project responds to the need identified by NIDCR to develop improved methods to detect and predict
progression of dental caries (tooth decay) to improve human health. Worldwide, caries is the most common
chronic disease affecting almost everyone. Dental disease is a major cause of economic and social loss and
leads to complications including pain, tooth loss and even death. Generally inactive lesions require no treatment
while active lesions do. Early active lesions permit conservative treatment, whereas cavitated lesions require
more costly and invasive restoration. Since the early 40’s, caries diagnosis has been performed visually and
using a dental explorer, but early cavities are missed and the explorer can cause cavitation. Alternatively, X-
Rays identify more fully developed cavities but are unable to identify early forming lesions. Newer methods for
caries diagnosis show little benefit and incur greater cost to dentist and patient. Current methods diagnose a
surface defect in the enamel but cannot distinguish “activity”, a critical need in modern dentistry. Our goal is to
develop a new clinically valid test to diagnose early and active carious lesions that also enables effective
monitoring of conservative treatment. We have invented a nanoparticle technology which specifically targets
active carious lesions. The nanoparticles are made from food grade corn starch and have been functionalized
to specifically target the subsurface of carious lesions. They are tagged with a safe fluorescent dye so the caries
will illuminate and be easily seen using a standard dental curing lamp, allowing dentists to quickly differentiate
whether a carious lesion is active or inactive and to monitor treatment results. The product is a mouth rinse or
oral gel containing a low concentration of the nanoparticles in water, enabling visual detection of early active
carious lesions otherwise invisible on the tooth surface, because the extremely small nanoparticles can penetrate
through surface microchannels into the early active sub-surface lesion. The starch-based nature of the
nanoparticles facilitates rapid degradation by amylase enzyme present in human saliva, so teeth will no longer
fluoresce upon leaving the dentist’s office. With earlier detection of caries and treatment of the disease before
cavitation occurs, invasive treatments will be prevented, resulting in the enablement of Minimally Invasive
Dentistry and improved oral health. Our Phase I research has demonstrated the potential of this technology,
and the functionalities on the nanoparticles were successfully optimized to provide a viable product with sufficient
targeting and fluorescence contrast to be macroscopically visible by the dental professional on various tooth
surfaces when using a standard dental curing light available in a dental practice. Phase II involves in vitro
assessment of the test’s diagnostic capabilities including in vitro sensitivity and specificity, in vivo biocompatibility
and studies required for FDA submission, clinical feasibility, and scaling of production. Successful completion
of the Phase II Aims will facilitate commercialization in Phase III, and meet clinical development, regulatory and
manufacturing milestones to support clinical validation and longitudinal clinical outcome studies.
