An Investigation About The Effects Of Fizzy Drinks On The Mechanical Properties Of Orthodontic Archwires

Abstract

Background and aim: One of the problems in fixed orthodontic treatments is the changes that occur in the mechanical properties of the orthodontic wires. The presence of surface roughness on orthodontic wires can affect the corrosion, friction, dental movement, biocompatibility, and esthetic. On the other hand, changes in the mechanical properties of used arch wires can influence the final results; also, cause tips, torque, and unwanted dental movements. Thus, this study addresses the evaluation and the measurement of the influence of the fizzy (carbonated drinks) on the mechanical properties of nickel titanium and stainless steel wires.

Method and material: The research was done experimentally on a NiTi and stainless steel wires. To do this, ten-round- orthodontic wire packages, with a diameter of 0.014 inches, rectangular (0.016*0.022 inches) were purchesed from American Orthodontics (AO) company and were prepared in 2.5 centimeters pieces. The samples were cleaned with alkaline solution and then mechanical properties of the wires such as yield strength, ultimate tensile strength and load deflection rate were tested by mechanical properties tensile testing machine and 3-point bending test. The samples were arranged in groups: 1- stainless steel rectangular 0.016*0.022. 2- stainless steel round 14.  3- Nickel titanium rectangular 0.016*0.022. 4- Nickel titanium round 14. The samples were chosen randomly. All the samples, initially, were inserted in plastic vial contains of 10 milliliter of carbonated drinks (pH = 2.74) for 5 minutes and then, were inserted in artificial saliva with pH = 7. The process was daily repeated for 30 days. Eventually, the same mechanical properties were re-evaluated and compared with the original amount, before the intervention.

Results: The statistical analysis of YS and LDR in the first group became significant (P = 0.037 and P<0.001). In the second group, the YS and LDR was significant too (P<0.001). The rate of changes on YS and LDR in the third and the fourth group were not significant. The rate of changes of UTS were not significant in any group (P<0.6).  Also, in intragroup comparison, the differences of YS, UTS, and LDR, before inserting the wires, in carbonated drinks showed that each variable in group 1 was more than the others. In group 2 was more than 3 and 4. In group 3 was more than group 4 significantly (P<0.001). The findings were also the same, after placing, the samples in the carbonated drinks (P<0.001).

Conclusion: It should be noted that limited studies were performed on the effects of fizzy drinks on the mechanical properties of the orthodontics wires. Based on the findings of this study, it can be concluded that the carbonated drinks can affect the mechanical properties and the treatment duration.