PERBANDINGAN KEKERASAN ANTARA EMPAT MACAM BRAKET STAINLESS STEEL BARU DAN PASCABAKAR DENGAN VARIASI WAKTU PEMBAKARAN

Abstract

Orthodontic bracket must have hardness and strength to be able to deliver the exact force. Contituent
material affects bracket endurance. One practical way to clean up the loose bracket before the rebonding process is
to burn the bracket base using a mini torch. The purpose of the study is to determine the hardness comparison among
4 types of stainless steel bracket, the hardness comparison between new stainless steel bracket and stainless steel
bracket which is burned using mini torch with burning time variation, as well as the interaction effect of the bracket
types and variation of the length of burning time on the hardness of stainless steel bracket.
        The experimental laboratory method was used in this study. Sixty premolar brackets from 4 types of stainless steel
bracket were used, each type consisted of 15 samples which were divided into 3 groups, group I was the new bracket,
group II and III were the brackets that was coated with adhesive material and burned using mini torch for 5 and 10
seconds, respectively. All samples were measured for hardness using a Vickers Microhardness Tester. The data was
analyzed with 2 ways Anova and Post Hoc Multiple Comparison.
        Result showed signifi cant difference of hardness (p<0.05) among the 4 types of stainless steel bracket, there was
signifi cant difference of hardness (p<0,05) between new bracket and post-burned bracket with 5 and 10 seconds of
burning time, there was no signifi cant difference (p>0,05) of interaction between bracket type and the length of burning
time towards hardness. It is concluded that bracket A had the highest and bracket B had the lowest hardness, meanwhile
bracket C and D had the same hardness. The new stainless steel bracket had the highest hardness compared with
bracket burned using a mini torch for 5 and 10 seconds. There was no interaction between the bracket type and the
length of burning time on hardness of the stainless steel bracket.