Silica Load and Flexural Strength of Pit-and-Fissure Sealants with Microcapsules

Objectives: The objective of this study was to determine the effect of fumed silica load on flexural strength of pit-and-fissure sealants formulated with microencapsulated remineralizing agents.
Methods: A heterogeneous polymerization technique was utilized to prepare microcapsules containing aqueous solutions of 0.8M NaF, 5M Ca(NO₃)₂ and 3M K₂HPO₄. These microcapsules were formulated into formulations of pit-and-fissure sealants. Several formulations were prepared that differed by the loading of fumed silica. An aliphatic urethane methacrylate and TEGMA were used as the continuous phase. In these formulations, the microcapsules were loaded 5w/w% (2w/w% of aqueous fluoride solution, 2w/w% of aqueous calcium solution and 1w/w% of aqueous phosphate solution). Flexural strength was assessed using specimens with a 2mm x 2mm x 20mm geometry in 3-point bend (n=12).
Results: Flexural strength was measured as a function of fumed silica loading. A table highlighting some of the results is shown below.
Conclusions: Mechanical properties were measured for sealants formulated with microencapsulated remineralizing agents. The preparation of formulations with a lower loading of fumed silica lead to improved flexural strength. This work is funded in part by Premier Dental Products Incorporated.