Gleb Komarov

Optical coherence tomography for dental caries detection and analysis

The ability of an en-face Optical Coherence Tomography (OCT) system to detect and quantitatively monitor the demineralization of teeth to produce enamel and dentine (root) caries was determined and validated with an established method of quantifying demineralization, transverse microradiography (TMR). We used an OCT system which can collect A-scans, B-scans (longitudinal images) and C-scans (en-face images). The development of enamel and root caries, by 3-day demineralization in acidic buffer solution, was assessed quantitatively every 24 hours. Caries lesions were shown as volumes of reduced reflectivity in both the transversal and longitudinal images. The A-scan, which showed the levels of reflectivity versus the depth of penetration into the tissue, was used for the quantitative analysis of the lesions. Results demonstrated that the reflectivity of tooth tissue decreased with increasing demineralization time. A linear correlation was observed between the mineral loss in enamel (r=1.0) and dentine (r=0.957) measured by TMR and the percentage reflectivity loss measured by OCT. We concluded that OCT could detect incipient enamel and root caries and quantitatively monitor the demineralization of the tissue. The reflectivity loss in tooth tissue during demineralization, measured by OCT, could be related to the amount of mineral lost during the demineralization.

Quantification of Canine Dental Plaque Using Quantitative Light-Induced Fluorescence:

The aim of this work was to evaluate Quantitative Light-induced Fluorescence (QLFTM) as an alternative to the established Logan and Boyce method for determining plaque coverage of dogs’ teeth. In a series of studies in conscious and anesthetized dogs, QLF showed good intra-photographer repeatability (coefficient of variation [CV] of 7.5% for undisclosed teeth) and inter-photographer reproducibility (CV of 3.2% for undisclosed teeth and 8.5% for disclosed teeth). The QLF software accurately identifies areas of plaque as demonstrated by comparison to the variability of 5 human scorers, manually marking plaque on QLF-acquired images (P = 0.1). There was good agreement with the modified Logan and Boyce method in the percentage reduction in plaque accumulation measured when dogs were fed an oral care chew versus no chew. To see a 15% difference in plaque accumulation, which is considered sufficient by the Veterinary Oral Health Council to differentiate between 2 treatments, a retrospective power analysis (90%) of the data established that only 7 dogs would be required, compared to 19 dogs for the modified Logan and Boyce method. QLF is a reliable method for measuring dental plaque in dogs with the added advantage that it is not subjective and requires fewer animals.

A randomised controlled trial to investigate the remineralising potential of Tooth Mousse™ in orthodontic patients

Objective To investigate the remineralisation of enamel subsurface lesions treated with fluoride toothpaste (1450 ppm) or a combination of fluoride toothpaste in addition to Tooth Mousse™. Design An in situ, cross-over, randomised controlled trial. Setting Orthodontic department at Liverpool University Dental Hospital, UK. Participants: Twelve patients receiving fixed orthodontic treatment. Methods: Demineralised subsurface enamel lesions were placed in a carrier and attached onto a fixed orthodontic appliance. Interventions were either standard fluoride toothpaste or CPP-ACP paste (Tooth Mousse™) in addition to the fluoride toothpaste. Participants received both interventions in a randomised order. Transverse microradiography analysis was used to compare lesion mineral content profiles. Results Mineral loss was reduced by 15.4 and 24.6% between the fluoride and CPP-ACP groups, respectively (p = 0.023). Lesion depth was reduced by 1.6 and 11.1% between the fluoride and CPP-ACP groups, respectively (p = 0.037). Lesion width was reduced by 4.5 and 15.3% between the fluoride and CPP-ACP groups, respectively (p = 0.015). Conclusions Remineralisation occurred regardless of treatment group allocation. However, the addition of Tooth Mousse™ resulted in a significantly increased remineralisation effect, compared to fluoride alone. Tooth Mousse™ may be beneficial for patients undergoing orthodontic treatment who are at high risk of demineralisation. Trial Registration Registered on Current Control Trials http://www.controlled-trials.com/ISRCTN04899524