Disclosed are embodiments of a dental prophylaxis angle. One dental prophylaxis angle includes a body having a neck that defines a first axial bore and a head that defines a second axial bore, the first and second axial bores communicating at an intersection and being angularly-offset from each other, a drive gear rotatably mounted in the first axial bore and having a drive gear head and a locking flange axially-offset from the drive gear head, an annular locking groove being defined between the drive gear head and the locking flange, a driven gear rotatably mounted in the second axial bore and operatively coupled to the drive gear, and a gear retainer having an annular body configured to extend about an outer surface of the head, a heel extending from the annular body, an arm extending from the heel, and a wedge extending from the arm.
