MANUFACTURER TOLERANCE IN SLOT HEIGHT OF 0.022-INCH MAXILLARY CANINE BRACKETS
Orthodontic brackets manufacturer does not reveal their actual slot height. Tolerance if present in bracket slot can lead to poor three-dimensional control of teeth. This study was done to determine the manufacturer tolerance in slot height of maxillary canine brackets.
Mesial and distal slots of one hundred and forty stainless steel maxillary canine brackets of seven commercial brands in 0.022-inch (“) slot were measured individually with leaf gauges of 0.01millimeter (mm) thickness. Digital readout in inches of leaf gauges was attained by micrometer. Descriptive statistics were generated for bracket slot height and one sample T test was used to check whether significant tolerance exist in slot height. A p value < 0.05 was considered as significant.
Smallest mean slot height of 0.0233+.0006 “ was noted in mesial slot of Db orthodontics brackets while largest mean height of 0.0258+.0015 “ were present in mesial slot of Mesal brackets. Maximum slot height of 0.028 “ was noted in Precise and Sia brackets. Increase tolerance in brackets were noted in the range of 5.9 to 17.2%. A p value < 0.05 was found in all the slot heights under study showing significant difference from acceptable tolerance.
All the bracket series have significant oversized slot height on both mesial and distal aspect. European orthodontic brackets were closer to standards than brackets manufactured in USA.