A dental matrix clamp includes an elongate body and a matrix band mountable relative to the body so as to form a loop projecting at one end of the body. The clamp has a tensioning device operable on the band to tighten the loop, and a deflector member which engages the band to provide an inclined conformation thereto. The deflector member is adjustable transversely across the band between opposite positions at which it bears against opposite peripheral portions of the band. The clamp is a hand-held device used in dentistry to clamp a band around a tooth for retention and molding of filling material.