Abstract: A matrix band retainer clip for sealing a matrix band against a tooth is provided. The retainer clip includes a pair of tines, each of which has a generally wedge shaped piece with a pair of contact surfaces that are angled relative to one another. A spring is coupled with and extends between the tines and biases the tines towards one another to apply a biasing force from at least one contact surface of each tine against the matrix band thereby sealing the matrix band against the tooth. The spring has a generally U-shaped portion with a pair of vertically extending legs coupled with the tines at their lower ends and interconnected at their upper ends by a generally laterally extending leg for distributing a stress across a length of the spring in response to the tines being separated from one another.