A Semi-Automated Method for Measuring Biofilm Accumulation on the Teeth Using Quantitative Light-Induced Fluorescence in Dogs and Cats

Oral health conditions (eg, plaque, calculus, gingivitis) cause morbidity and pain in companion animals. Thus, developing technologies that can ameliorate the accumulation of oral biofilm, a critical factor in the progression of these conditions, is vital. Quantitative light-induced fluorescence (QLF) is a method to quantify oral substrate accumulation, and therefore, it can assess biofilm attenuation of different products. New software has recently been developed that automates aspects of the procedure. However, few QLF studies in companion animals have been performed. QLF was used to collect digital images of oral substrate accumulation on the teeth of dogs and cats to demonstrate the ability of QLF to discriminate between foods known to differentially inhibit oral substrate accumulation. Images were taken as a function of time and diet. Software developed by the Cytometry Laboratory, Purdue University quantified biofilm coverage. Intra- and intergrader reproducibility was also assessed, as was a comparison of the results of the QLF software with those of an experienced grader using undisclosed coverage-only metrics similar to those used for the Logan and Boyce index. Quantification of oral substrate accumulation using QLF-derived images demonstrated the ability to distinguish between dental diets known to differentially inhibit oral biofilm accumulation. Little variance in intra- and intergrader reproducibility was observed, and the comparison between the experienced Logan and Boyce grader and the QLF software yielded a concordance correlation coefficient of 0.89 (95% CI = 0.84, 0.92). These results show that QLF is a useful tool that allows the semi-automated quantification of the accumulation of oral biofilm in companion animals.

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.

Evaluation of a Hydrophilic Gingival Dental Sealant in Beagle Dogs

A liquid solution, gingival sealant containing polymers that form a barrier film upon application was evaluated in dogs. It is a non-toxic, low viscosity, hydrophilic barrier sealant that dries in approximately 10 to 15-seconds after subgingival application. It was designed as a preventative to be applied immediately following a professional oral hygiene procedure in order to block plaque and calculus formation in the sulcus and aid in the prevention of periodontal disease in companion animals. Additionally, the polymer was designed to promote an aerobic environment in the sulcus by oxygen and water transport through engineered pores within the polymer. A 30-day split-mouth, blinded study in two groups of 15 beagle dogs was used. Plaque was significantly (p < 0.05) reduced on the side receiving the sealant by 30.0 % and 50.5 % (average = 40.3 %) in groups 1 and 2, respectively. Calculus was significantly (p < 0.05) reduced on the side receiving the sealant by 27.2 % and 20.0 % (average = 23.6 %) in groups 1 and 2, respectively. Gingival inflammation was monitored to assess product safety. Sides receiving sealant showed no statistically significant differences in gingival index score. No adverse events were observed in the study. This study demonstrates that this gingival sealant can be used as another valuable tool for aiding in the prevention of periodontal disease in dogs.