PURPOSE: The purpose of this study was to evaluate the effect of a flowable glass ionomer cement (GIC) layer application on bond strength to sound (SD) and carious primary dentin (CD). METHODS:Flat dentin surfaces from primary molars were randomly assigned to 4 groups (N=5) according to substrate (SD or CD; pH-cycling for 14 days); and layers of GIC (1 layer/control [regular powder/liquid ratio] or 2 layers [first a flowable GIC layer and second a regular powder/liquid ratio layer of GIC]). After 24 hours of water storage, specimens were prepared to be evaluated with the microtensile test (1 mm/min). The fracture pattern was evaluated at 400X magnification (stereomicroscope). RESULTS: The bond strength to SD was higher than to CD when GIC was inserted in 2 layers (P=.02). No significant difference was observed between 1 or 2 layers of GIC insertion (P>.05). For all groups, adhesive/mixed fracture prevailed. CONCLUSION: The effect of applying the flowable GIC layer on bond strength to dentin is dependent on substrate and results in an increase in adhesion for sound primary dentin.
RCT Entities:
PURPOSE: The purpose of this study was to evaluate the effect of a flowable glass ionomer cement (GIC) layer application on bond strength to sound (SD) and carious primary dentin (CD). METHODS: Flat dentin surfaces from primary molars were randomly assigned to 4 groups (N=5) according to substrate (SD or CD; pH-cycling for 14 days); and layers of GIC (1 layer/control [regular powder/liquid ratio] or 2 layers [first a flowable GIC layer and second a regular powder/liquid ratio layer of GIC]). After 24 hours of water storage, specimens were prepared to be evaluated with the microtensile test (1 mm/min). The fracture pattern was evaluated at 400X magnification (stereomicroscope). RESULTS: The bond strength to SD was higher than to CD when GIC was inserted in 2 layers (P=.02). No significant difference was observed between 1 or 2 layers of GIC insertion (P>.05). For all groups, adhesive/mixed fracture prevailed. CONCLUSION: The effect of applying the flowable GIC layer on bond strength to dentin is dependent on substrate and results in an increase in adhesion for sound primary dentin.