Bur No.957, No.557, and No.57 may have which of the following characteristics in common?
All original bur designs had continuous blade edges. Later, when crosscut burs were found to be more effective for cutting dentin at low speeds, crosscut versions of many bur sizes were introduced. This modification was indicated by adding 500 to the number of the equivalent noncrosscut size. Thus, a No.57 with crosscut was designated No. 557. Similarly, a 900 prefix was used to indicate a head design intended for end cutting only. Except for differences in blade design, a No.957, No.557, and No.57 bur all had the same head dimensions.
Ref: Sturdevant's art and science of operative dentistry. 4th edition page 332
Head dimension
Blade design
Function
All of the above