Aims: To evaluate the degree of change that may occur in reconditioning the titanium bracket via mi- cro-etcher. Materials and Methods: The sample consisted of (10) pure titanium brackets for each of control and reconditioning brackets. The parameters of the reconditioned bracket (slot width, slot depth, inter-wing gap, labio-lingual angle and base curvature angle) were measured and compared with that of the control bracket. Results: The results showed no significant difference between the con- trol and reconditioned brackets of the slot parameters (width, depth, inter-win gap, labio-lingual an- gle) and the bracket’s base curvature angle. While, the tensile bond strength of the control brackets showed significantly higher mean value as compared with the recycled group. Conclusions: The re- conditioning of pure titanium brackets is recommended for reuse in the orthodontic treatment after ster- ilization.
Key Words: Micro-etcher, width, depth, inter-wing, labio-lingual, base.
If the patient does have a true intra oral nickel allergy, pure titanium brackets which are nickel free can be used (1 ). Re- cycling is considered as a solution of using the same bracket for another patient after the process of sterilization (2 ). The manu- facturers of micro-etching device have suggested the use of an air abrasive tech- nique sandblast to improve the bond strength of metal braised brackets (3–5).
Kocadereli et al. (6 ) stated that an accept- able bond strength was achieved when the recycled bracket sandblasted by using the aluminum oxide particles. Recycling proc- ess consists basically of the removal of residual glue or remnant bonding material from debonded bracket without distortion of bracket slot dimension (width, depth) and the delicate mesh (7 -9 ) Tavares et al. (8 ) used the sandblast to remove the adhesive from the bracket pad or base and found that the bond strength of recyclable bracket was not significantly different when compared with new attachment. Other authors (10,11 ) demonstrated that the sandblasted or recyclable brackets showed a significant reduction of bond strength when compared with a new bracket. Basu- dan and Al-Emran (12 ) studied the effect of sandblast on the slot s width, depth and inter-wing gap of the reconditioned brack- et, and found no effect of sandblast on them.
The aims of this study are to evaluate the degree of changes in bracket slot (width, depth, labio–lingual inclination angle, and inter–wing gap) and bracket base curvature angle that may occur in reconditioning the titanium bracket via micro–etcher.
MATERIALS AND METHODS
The bracket samples consisted of (20) pure bicuspid titanium brackets ( 0.466 x 0.760 mm) with casted integral base. The brackets were classified into two groups, 10 brackets for each. The first group used as control, the second group used for con- ducting the reconditioning technique. Twenty sound extracted human upper right first premolars were utilized to test the tensile strength of control group and re- conditioned group.
1 Ireland AJ and McDonald F. The orthodontic patient: treatment and biomechanics. Oxford University Press. 2003; Pp: 223-227.
2 MacColl GA, Rossouw PE, Titley KC, Yamin C. The relationship between bond
strength and orthodontic bracket base surface area with conventional and micro- etched foil-mesh bases. Am J Orthod Dentofacial Orthop. 1998; 113: 276-281.
3 Sonis AL. Air abrasion of failed bonded metal brackets: a study of shear bond strength and surface characteristics as determined by scanning electron microscopy. Am J Orthod Dentofacial Orthop. 1996; 110: 96-98.
4 Wood DP, Paleczny GJ, Johnson LN. The effect of sandblasting on the retention of orthodontic bands. Angle Orthod. 1996; 66: 207-213.
5 Brosh T, Kaufman A, Balabanovsky A, Vardimon AD. In vivo debonding strength and enamel damage in two orthodontic debonding methods. J Biomechanics. 2005; 38: 1107-1113.
6 Kocadereli I, Canay S, Akca K. Tensile bond strength of ceramic orthodontic brackets bonded to porcelain surfaces. Am J Orthod Dentofacial Orthop. 2001; 119: 617- 620.
7 Graber TM and Vanarsdall RL. Orthodontics current principle and techniques. 3rd ed. St Louis: C.V. Mosby. 2000; Pp: 557559, 592.
8 Tavares SW, Consani S, Nouer DF, Mag- nani MB, Neto JS, Romano FL. Evaluation in vitro of the shear bond strength of aluminum oxide recycled brackets. Braz J Oral Sci. 2003; 2: 378-381.
9 Quick AN, Harris AM, Joseph VP. Office reconditioning of stainless steel orthodontic attachments. Eur J Orthod. 2005; 27:231-236.
10 Sharma-Sayal SK, Rossouw PE, Kul- karni GV, Titley KC. The influence of orthodontic bracket base design on shear bond strength. Am J Orthod Dentofacial Orthop. 2003; 124: 74-82.
11 Schmage P, Nergiz I, Herrmann W, ozcan
M. Influence of various surfaceconditioning methods on the bond strength of metal brackets to ceramic surfaces. Am J Orthod Dentofacial Or- thop. 2003; 123: 532- 537.
12 Basudan AM and Al-Emran SE. The effects of in-office reconditioning on the morphology of slots and bases of stainless steel brackets and on the shear/ peel bond strength. Bri J Orthod. 2001; 28: 231-236.