Method: 60 freshly extracted human premolars with intact enamel were selected. Teeth went through professional cleaning procedures and their roots were embedded in acrylic resin. The specimens were assigned to 5 groups (n = 12) according to 5 different orthodontic adhesives used for bracket bonding: two resin modified glassionomer based materials and three resin based. Initial tooth colour parameters (L*, a*, b*, C, h) were recorded using the ShadePilot (Degudent) Spectrophotometer on two separate standardised buccal sites (occlusal third and facial axis (FA) point). 60 standard edgewise stainless steel premolar brackets were directly bonded to the labial surfaces of the teeth following the manufacturers’ bonding protocol for each of the materials on FA point. Afterwards teeth from each group were divided in 3 smaller groups (n=4) to undergo three separate procedures: accelerated coffee staining, bleaching and control protocol. Afterwards, brackets were debonded and a second colour determination was done on the same predetermined buccal sites. The data was interpreted using SPSS Software.
Result: Statistical interpretation of data from our preliminary study revealed significant differences of tooth colour behaviour between the areas located under orthodontic bracket (FA) and control areas (occlusal third) depending on the staining/whitening procedure used and on the adhesive.
Conclusion: The effects of each adhesive upon enamel surface should be known prior to cosmetic bleaching procedures on patients undergoing orthodontic treatment in order to avoid possible prejudice to aesthetic appearance after debonding.