Assessment of early occlusal caries pre- and post-sealant application--an imaging approach

BACKGROUND AND OBJECTIVE

Clinicians have difficulty assessing and monitoring early occlusal caries. Traditional clinical exam and radiographs are unable to detect the subtle alterations in enamel indicative of de- or re-mineralization, particularly under dental sealants. Although clinicians have used laser fluorescence (LF) to address this gap, this modality has demonstrated weak correlation with histology. The International Caries Detection and Assessment System (ICDAS-II) has demonstrated high sensitivity and specificity for caries detection, but since it is based on visual assessment, it is of no use in areas beneath the most commonly used dental sealants which are opaque. Optical coherence tomography (OCT) is an emergent assessment tool which has demonstrated great promise in detecting and quantifying caries, including areas beneath commonly used dental sealants and composites. However, OCT has not yet been widely integrated into clinical dental practice, perhaps because OCT imaging does not provide an easily accessible diagnostic outcome for clinicians. The objective of this ex vivo study was to use OCT-images of sound and carious occlusal surfaces in combination with a simple algorithm to compare the caries detection ability of OCT with tools clinicians may be more familiar with (LF and radiography), and with an established valid and reliable clinical assessment tool (ICDAS-II).

STUDY DESIGN/MATERIALS AND METHODS

One hundred twenty extracted teeth with sound or naturally carious occlusal surfaces were imaged with OCT, LF, radiography, and examined clinically with the ICDAS-II. Teeth were randomized to one of two dental sealants recommended for use with LF. A novel simple algorithm was used to interpret OCT-based images. The accuracy of caries severity assessments of the OCT-based diagnosis, LF, ICDAS-II, and digital radiography were compared to the 4-point histological analysis gold standard.

RESULTS

OCT and ICDAS-II caries severity assessments demonstrated high sensitivity (94.0%; 92.3%) and specificity (85.0%; 83.3%), LF demonstrated low sensitivity (65.2%) but high specificity (97.6%), and digital radiography demonstrated low sensitivity (67.1%) with moderate specificity (79.5%) on unsealed occlusal surfaces. OCT-based caries severity assessments of sealed teeth demonstrated high specificity (97.6%), sensitivity (89.9%), excellent positive predictive value (98.6%), and negative predictive value (83.3%). Despite our use of LF recommended dental sealants, in the presence of sealants, LF assessment of caries severity demonstrated high sensitivity (95.1%), but extremely low specificity (10.3%), positive predictive value (68.8%), and negative predictive value (50.0%).

CONCLUSION

This study found that OCT-based imaging combined with a simple diagnostic algorithm accurately assessed the severity of natural early caries on occlusal surfaces in extracted teeth both in the absence and presence of dental sealant. The findings of this study support the clinical use of OCT imaging for assessment and monitoring progression of early non-cavitated caries lesions on occlusal surfaces including areas under dental sealants.

A prospective study to assess in vivo optical coherence tomography imaging for early detection of chemotherapy-induced oral mucositis

BACKGROUND AND OBJECTIVE

Oral mucositis (OM) is a common and severe complication of many cancer therapies. Currently, prediction and early detection are not possible and objective monitoring remains problematic. Goal of this prospective study is to assess non-invasive imaging using optical coherence tomography (OCT) for early detection and evaluation of chemotherapy-induced OM in 48 patients, 12 of whom developed clinical mucositis.

STUDY DESIGN/MATERIALS AND METHODS

In 48 patients receiving neoadjuvant chemotherapy for primary breast cancer, oral mucosal health was assessed clinically, and imaged using non-invasive OCT. Images were evaluated for mucositis using an imaging-based scoring system ranging from 0 to 6. Conventional clinical assessment using the OM assessment scale (OMAS) was used as the gold standard. Patients were evaluated on Days 0-11 after commencement of chemotherapy. OCT images were visually scored by three blinded investigators.

RESULTS

The following events were identified from OCT images (1) change in epithelial thickness and subepithelial tissue integrity (beginning on Day 2), (2) loss of surface keratinized layer continuity (beginning on Day 4), (3) loss of epithelial integrity (beginning on Day 4). Imaging data gave higher scores compared to clinical scores early in treatment, suggesting that the imaging-based diagnostic scoring was more sensitive to early mucositic change than the clinical scoring system. Once mucositis was established, imaging and clinical scores converged.

CONCLUSION

Using OCT imaging and a novel scoring system, earlier, more sensitive detection of mucositis was possible than using OMAS. Specific imaging-based changes were a consistent predictor of clinical mucositis.

An imaging-based approach to the evaluation of xerostomia

BACKGROUND AND OBJECTIVE

Goal was to evaluate the potential of in vivo optical coherence tomography (OCT) imaging to determine the response of patients with xerostomia to a dry mouth toothpaste versus fluoride toothpaste placebo.

STUDY DESIGN/MATERIALS AND METHODS

Ten subjects with xerostomia participated in this double-blind, crossover, placebo-controlled study. After examination and OCT imaging, subjects used the first product for 15 days, followed by a 7-day washout period, and then they used the second product for 15 days. Data were acquired at 5-day intervals, also before and after the washout.

RESULTS

Visual examination and tongue blade adhesion test did not reflect response to the product. Two imaging-based markers were identified: (i) In OCT images, epithelial thickness increased significantly (P < 0.05) after use of the dry mouth toothpaste, but did not change significantly (P > 0.05) after the use of a fluoride toothpaste and (2) Optical backscattering data showed progressive characteristic changes from baseline with use of the active product.

CONCLUSIONS

In this pilot study using in vivo OCT imaging, it was possible to detect and measure oral epithelial response to the dry mouth product versus placebo in patients with xerostomia.

CLINICAL IMPLICATIONS

This approach may permit site-specific assessment of xerostomia, individualized treatment planning and monitoring, and sequential mucosal mapping in patients with dry mouth.