In vitro Prevention of Non-carious Cervical Lesion Under Tribological Model

Objectives: Minimally invasive therapies targeting the organic and inorganic components of dentin could be powerful tools in the prevention and control of non-carious cervical lesions. The aim of this study is to evaluate potential protective role of a Fluoride/Calcium/Phosphate varnish and proanthocyanidins from Cinnamon on the roughness, hardness, volume loss and coefficient of friction of cervical root dentin under in vitro tribological model.
Methods: Root dentin of 18 human molars were polished and protected except for a 3×4mm window. The specimens were divided and treated according to surface treatments: MI- Fluoride/Calcium/Phosphate varnish for 4 hours (MI Varnish-GC), CE- 1% Cinnamon extract in HEPES solution for 1 hour, and C- no treatment (control). After treatment, the specimens were stored overnight in buffer with bacterial collagenase (200μg/ml Clostridium histolyticum) at 37°C to simulate proteolytic challenge. Then, dentin surfaces were subjected to a pin-on-plate tribological contact method (1Hz frequency, 3.7N load) in artificial saliva (pH4) at 37°C for 24h. The evolution of friction coefficient was monitored as a function time. The dentin surfaces were evaluated using digital profilometry (roughness, volume loss) and microhardness measurements. Data were statistically analyzed with ANOVA and Tukey tests (α=0.05).
Results: The dentin treated with CE presented the lowest roughness comparing to MI and C groups (p=0.008). Higher values of hardness were observed for CE followed by MI and C (p<0.001). Statistical differences in volume loss (p=0.037) depict lower values for CE≤MI≤C. A 10% reduction in the coefficient of friction was observed in CE and MI compared to C (p<0.001).
Conclusions: Surface treatment with Cinnamon and Fluoride/Calcium/Phosphate varnish appear to be promising treatments for the prevention of non-carious cervical lesion under tribological method.