Aims: To evaluate the effects of the micro-etching procedure on the bracket’s slot and base parameters and on the tensile bond strength of the recycled brackets. Materials and Methods: The sample was 20 stainless brackets grouped into; control brackets group(10) and de-bonded brackets group(10). The debonded brackets reconditioned with micro-etcher. the data subjected to the statistical analysis at 0.05 significant level. Results: demonstrated that the use of micro-etcher for recycling the de-bonded brackets do not affect the bracket’s slot and base parameters whereas affected the bond strength of the recycled brackets. Conclusion: The micro-etcher (sand basting) is recommended for recycling the de-bonded stainless steal brackets and reuse them in orthodontic treatments
Key words: Orthodontic brackets; micro-ether; recycling.
Recycling appears to be an effective method for cleaning brackets after acid- ental debonding and facilitating the reuse of accidentally debonded attachments.(1 ) Rec- ycling is considered as a solution for using the same bracket for another patient after sterilization.(2 ) Recycling has an economic and ecological benefit due to the cost of re- used bracket below the price of new brac- ket.(3 )
Micro-etching, this method used for removing the old adhesive from the base of de-bonded bracket in order to improve the retentive surface of the base or pad of the de-bonded bracket. This technique utilized a high speed stream of aluminum oxide pa- rticles propelled by compressed air, althou- gh initially reintroduced as a method for ro- ughing the surface of many dental materials (etch attachment for superior Maryland bri- dge, etch orthodontic band for rapid cement removal from internal surface of crown and bridge prior to re-cementation).(4 ) Another application of micro-etcher; etches all me- tals amalgam, composite, porcelain repa- ir.(5 ) Basudan and Al-Emran (6 ) studied the effect of sandblast on slot width and slot depth, inter-wing gap of reconditioned bra- cket, and found no effect of sandblast on them. Authers (7,8 ) showed that bond streng- th of recyclable bracket was not significant when compared with new brackets. Other researchers (9,10 ) disagreed with this finding, such as, Chung (9 ) who noticed the signific- ant difference in bond strength between re- cyclable bracket that etched by sandblast when compared with the new one. This co- ntroversy required more research to ensure the right findings. The aims of this study were planned to asses the bracket dimens- ions of the slot s, width, depth, inter-wings gape, labio-lingual angle and the bracket’s base curvature angle of the recycled stainle- ss bracket.
MATERIALS AND METHODS
The bracket samples consisted 20 stain- less steal (SS) standard edge wise (0.018 x 0.0300 of the bicuspid bracket with a single layer mesh (foil mesh). The brackets grou- ped into two groups, 10 brackets for each. The first group used as control, the second group used for conducting the recycling tec- hnique. Twenty sound extracted human upp- er right first premolars utilized for testing the tensile strength for control and recycling groups. The teeth collected from orthodontic department in the dental school at College of Dentistry, University of Mosul. The teeth did not subjected to any pretreatment, with no detectable caries or enamel cracks and no visible hyper-plastic pits and intact buccal enamel.(11 ) The teeth stored in normal saline 0.9 NaCl.(12 )
The second brackets group bonded on glass via orthodontic composite adhesive. The bonding process performed under a sta- ndard force 500 gm,(6 ) excess resin flash ar- ound the base removed with dental explorer. The bracket de-bonded by using tweezers after one hour.
Micro-etching of the de-bonded brack- ets achieved with Micro-etcher. The micro- etcher is designed to be held like a pencil al- lowing the thumb to activate the finger butt- on control, the nuzzle holed 3 mm away fr- om the bracket base.(13 ) The tip of the nuzzle moves in a mesiodistal direction in sweep te- chnique by using a holder designed to make the nuzzle move for 6 mm mesiodistal direc- tion, and the base of the de-bonded bracket etched for 12 seconds with aluminum oxide 50 micron particle size.(9 )
The parameters (slot s; width, depth, in- ter-wings gap) of the bracket measured un- der the stereomicroscope at a constant qual- ity and then, converted to their original val- ues. The measurements of the slot’s width of the bracket which measured by reading the distance from the tope of the internal co- rners of the gingival and the occlusal of the mesial wings, the slot depth measured by reading the distance of the tangent line at the internal wall of the slot and the inter-wing gap measured by reading the distance betw- een two points at the internal corners of me- sieoocclusal and distoocclusal wings (Figure 1).
illustration not visible in this excerpt
Figure (1): The stainless steal bracket’s dimensions: (A) slot width , (B) slot depth ,
(C) Inter-wings gap.
The labiolingual angle measured by the intersection of the tangant lines of the inter- nal surfaces of the mesio-oclclusal wing and the occluso-gengival floor of the slot and the bracket’s base curvature angle found by the intersection of the tangent lines of the mesial and distal slops of the bracket’s base, these angles measured on the magnified ph- otographs (20X) (Figure 2).
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- Quote paper
- Dr. Amer A. Taqa (Author)Hussain A. Obaidi (Author)Omar H. Al-Luazy (Author), 2007, Stainless steal orthodotic brackets recycling (using micro–etcher), Munich, GRIN Verlag, https://www.grin.com/document/207700