Abstract: A dental air-water syringe includes a handle and a tip as well as a device for purifying water flowing through the tip. In one embodiment of the invention, the water purifying device is contained within a housing of the tip and optionally includes a number of iodide beads disposed along the length of the housing. In another embodiment of the invention, the device is detachably connected to the tip, and the tip and the device have outer diameters that are approximately equal.

Abstract: A method is disclosed for controlling the coupling low molecular weight ligands to activated sites on a support in competition with a quencher of the activated sites. Derivatized supports produced by the method have optimal ligate binding without overly dense binding sites or stearic effects. Azlactone-functional supports, especially porous supports such as porous particles, benefit from control of ligand density. A linear relationship exists between the molar ratio of ligand and quencher and the coupled ligand density. Optionally, hydrophilicity of the derivatized support can be determined by selection of quencher relative to selection of ligand.