A reduction burr for universal application for depth reduction of dental or ossiferous surfaces includes a shank of a first diameter extended to a chamfered rim angled radially inwardly to a smaller second diameter. A curved shoulder extended from the chamfered rim decreases in cross-sectional diameter to a distal end having a third diameter. A burr end having an abrasive surface thereon is extended from a junction with the shoulder distal end to a distal burr end, with the abrasive surface having sufficient hardness to cut enamel or ossiferous surfaces. The junction defines a precise stop for self-limiting the burr penetration depth into the enamel or ossiferous surfaces due to the greater second diameter of the curved shoulder contacting against adjacent uncut surfaces. A method of size reduction is disclosed for universal application of a reduction burr to precisely reduce enamel or ossiferous surfaces in both lateral and longitudinal directions.