THE DIFFERENCE OF ZIG-ZAG SHAPED TAG LENGTH OF ORTHODONTIC WIRE IN ACRYLIC PLATE ON THE PRESSURE STRENGTH
The success of the treatment using removable orthodontic appliance not only depends on the patient’s will to use it but also on the operator’s capability to design and to make an appropriate appliance that may be tolerated by the patient. In orthodontic clinic, the tag can be used in zigzag shape, however, the length of zigzag shaped tag in its construction, so far, is determined based on the taste of the operator and not yet considered efficient length to avoid reducing the elasticity of the plate on the pressure strength. This study is aimed to observe the difference of zigzag shaped tag length of orthodontic wi re in acrylic plate on the pressure strength. Methods: 18 samples of acrylic plate, divided into 3 groups (G1: the length of the zigzag shaped tag in acrylic plate was 10 mm, G2: 12,5 mm, G3 : 15 mm), with the thickness of 2 mm, 3 x 2,5 using negative casting or each plate, tags were put in line with the space of 1 cm and poured with acrylic resin mixture and subsequently pressed. After being hardened, the resin acrylics were then taken out, softened, and polished. The measurement of pressure strength on the acrylic plate was conducted using Company Universal Testing Machine 30 KN Model TM 133 Essom Limited. The data collected were tested using One way Anova (p=0,05), and LSD test to observe the difference among the group. Results : the result of the study showed no difference of pressure strength among the groups. The One way Anova demonstrated value of 0,715 (p>0,05). It showed that among the three groups, there was no signifi cant difference on their pressure strength. Conclusion: It was due to no difference of the length of zigzag shaped tag in the acrylic plates, the longer tag was the less pressure strength produced.