Sandblasted crowns increase bond strength of orthodontic brackets, Finds study
Orthodontic bonding of brackets to teeth is a standard procedure to align teeth with fixed appliances. However, the bracket bonding to provisional crowns has always been speculated at every stage. A recent research conducted at the Department of Preventive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia has found out that under thermocycling conditions, sandblasting of provisional crowns increases the bond strength of orthodontic brackets.
The study is published in the International Journal of Dentistry.
The number of patients seeking orthodontic treatment has been consistently increasing. During orthodontic treatment, it is recommended to place the provisional restoration and to delay the final restoration until completion of orthodontic treatment. Recurrent bracket debonding necessitates orthodontists to prepare the bonding area with special measures.
Therefore, Suliman Y Shahin and associates carried out the study aimed to evaluate the effect of different grit sizes of diamond burs and sandblasting surface treatment on the shear bond strength of orthodontic brackets to provisional crowns.
A total of 75 discs were fabricated from a bisacrylic composite and divided into 5 groups (n = 15) according to surface treatment by black, blue, and green diamond burs and sandblasting in addition to a control group.
Metal orthodontic brackets were bonded to discs in a standardized conventional manner. All specimens were subjected to thermocycling with 5000 cycles of alternating 5°C and 55°C waterbaths. The shear bond strength test was performed using a universal testing machine.
A scanning electron microscope (SEM) was used to analyze the surface treatment effect and features of debonded surfaces. The amount of composite resin left on the specimen surfaces was analyzed and classified with the adhesive remnant index. One-way ANOVA was performed at α = 0.05.
The results showed that the shear bond strength of specimens treated with sandblasting was significantly higher than that of the control group under thermal aging conditions as well as blue burs, while no significant differences were found between different grit diamond burs and the controls.
As a result, the investigators concluded that "sandblasted provisional crowns would increase the bond strength of orthodontic brackets. Also, under thermocycling conditions, surface grinding of provisional crowns by super coarse diamond burs could increase the bond strength of brackets to tolerate limited orthodontic forces."