The present invention discloses a dental drill comprising a drill body, a stationary ring No. 1 and a stationary ring No. 2. The drill body can be embedded in the dental handpiece and rotated at a high speed, and the stationary ring sleeve portion is formed on the drill body, and can be selected for the stationary ring No. 1 or the stationary ring No. 2； the drill body is a drill portion, and the drill portion is stepped. The cutting edge has a circular diameter defined as a first blade portion, a second blade portion, a third blade portion and a fourth blade portion； when the stationary ring No. 1 or the stationary ring No. 2 is placed on the stationary body of the drill body When the ring is fitted, some of the blades of the hidden drill body can be covered, and at the same time, the end of the stationary ring can also be used as a limiter for the drilling.本創作揭露一種牙科鑽頭，其包含由鑽本體、1號靜止環與2號靜止環所構成。鑽本體可嵌入牙科手機並藉以高速轉動，鑽本體上形成靜止環套合部，可選擇供1號靜止環或2號靜止環套入；鑽本體下方為鑽頭部，該鑽頭部呈一階梯狀之鑽刃，其圓徑由大至小定義為第一刃部、第二刃部、第三刃部及第四刃部；當1號靜止環或2號靜止環套置於鑽本體之靜止環套合部時，可以覆蓋隱藏鑽本體的某些刃部，同時，靜止環末端亦得作為鑽孔的限位依據者。
