effect of fast curing lights, argon laser, and plasma arc on bond strengths of orthodontic brackets: an in vitro study

objective: nowadays light-cured composites are used widely by orthodontists to bond brackets. as these composites require 20-40 seconds time per tooth to be light cured, more chair-time in needed compared to self-cured composites. in recent years, the argon laser and plasma arc lights have been introduced in dentistry to reduce this curing time. the purpose of this study was to compare bond strength of brackets bonded with the argon la-ser and plasma arc light with those bonded with the conventional halogen light. materials and methods: fifty-one intact human premolars were randomly divided into three groups of 17 teeth each. stainless steel twin premolar brackets (018- in dyna lock, 3m unitek) were bonded to the teeth using one of these curing devices in each group: the halogen unit (coltolux 75, switzerland), the argon laser unit (bo-5, iran ), and the plasma arc unit (remecure 15, belgium). the orthodontic adhesive was the same in the three groups (transbond xt, 3m unitek). after thermal cycling, the diametral tensilebond strength of specimens was measured using a debonding plier in a zwick universal testing machine (z/100, germany). results: the mean bond strengths was 17.344 mpa (sd=4.567) for halogen 19.172 mpa(sd=6.328) for laser and 19.322 mpa (sd=4.036) for plasma arc groups. no statistically significant difference existed in the mean bond strengths among three groups. conclusion: argon laser lights, significantly reducing the curing time of orthodonticbrackets without affecting bond strength, have the potential to be considered as advanta-geous alternatives to conventional halogen light.