2011 Volume 45 Issue 1 Pages 103-109
We did an in vivo study of how the multifunctional vacuum tip and self-adhesive cement affected the bond strength between cement and core materials. A factorial design experiment was performed based on the design of experiments (DOE). As control factors, environmental conditions and types of cement were assigned to the inside cross table for full factorial design. As noise factors, insertion area 1, insertion area 2, subjects, clinical experience of the operators, and adherends were assigned to the outside cross table of the L9 orthogonal array. The bonding was done by two dentists on four teeth in two subjects under three operating environments using three different cements. The relative humidity in the mouth was measured at two locations under each operating environment. To compare humidity at different intraoral temperatures, the intraoral relative humidity was converted into the intraoral absolute humidity. Shear bond strength was analyzed using the signal-to-noise ratio. We found that the combination of a multifunctional vacuum tip and self-adhesive cement produced the best results. The multifunctional vacuum tip resulted in the lowest relative humidity. We concluded that the multifunctional vacuum tip and self-adhesive cement were useful in the bonding operation.