GICs have good adhesive relations with tooth substrates, uniquely chemically bonding to dentine and, to a lesser extend, to enamel. During initial dissolution, both the glass particles and the hydroxyapatite structure are affected, and thus as the acid is buffered the matrix reforms, chemically welded together at the interface into a calcium phosphate polyalkenoate bond. In addition, the polymer chains are incorporated into both, weaving cross links, and in dentine the collagen fibres also contribute, both linking physically and H-bonding to the GIC salt precipitates.