Shear bond strength of the Iingually and buccally bonded brackets via three composite systems

Abstract

This study aimed to determine and compare the shear bond strength of lingually
bonded brackets via: Two—paste composite (Orthodontic Mix Bonding System), No —
mix composite [Orthodontic Bonding System (No—mix)] and Light—cured composite
( Transbond XT .)
Thirty extracted upper first premolars for orthodontic request were used for this
investigation. The teeth were divided into three groups; each of which consisted of l0
teeth. The lingual surface of the tooth used to evaluate the lingual bond strength and
the buccal surface of the same tooth utilized to evaluate the buccal bond strength. For
each group of teeth investigated to determine the lingual and buccal bond shear
strength, using one type of composite system for each group .
The lingually bonded and buccally bonded samples were subjected to shear
force using the universal compression testing machine apparatus. The lingual and
buccal shear bond strengths were recorded and converted into Mpa and the data were
statistically analyzed .
The results showed the lingual shear bond strength insignilicantly less than that
of buccal shear bond strength regarding the Orthodontic Mix Bonding System and
Orthodontic Bonding System (No—mix), and the lingual shear bond strength was
significantly less than the buccal shear bond strength regarding Light—cured
composite (Transbond XT), The lingual and buccal shear strengths of the bonded
bracket via Orthodontic Mix Bonding System were the highest than the shear bond
strength of the other composite systems