Bond strength and clinical efficiency for two light guide sizes in orthodontic bracket bonding.

Abstract

The purpose of this study was to establish a possible increase in efficiency in bracket bonding with light-cured adhesive by using a larger size on the light transmitting unit. Two light guides were compared, a standard-sized 11-mm light guide and a 19-mm elliptical extra broad light guide, the latter designed to allow simultaneously curing of two adjacent brackets. Fifty extracted human premolars mounted in five phantom maxillary arches were bonded according to a standard procedure with Mini Uni-Twin stainless steel brackets. The two light guides were randomly chosen for each half of the maxillary arch. After bonding, all teeth were tested for tensile bond strength to failure. In the clinical study 30 patients were bonded according to a split mouth technique with the two light guides alternatively used randomly for each side of the jaw. Time for bonding and the occurrence of bracket failures were recorded. The results showed no statistically significant differences between the standard and elliptical light guides regarding tensile bond strength, or bracket failure frequency. However, with the larger light guide size a significantly shorter total bonding time for each patient was required. It is therefore concluded that the elliptical light guide in combination with a light transmitting unit of sufficient quality gave a similar bonding result as the standard light guide, offering the clinician a reduction in chair side time during the bonding procedure.