Citation Information :
Balakrishnan A, Antony V, Shaloob M, Roshan G, Nayaz M, Parayaruthottam P, Haris M. Effect of Different Light-tip Distances on Shear Bond Strength of Orthodontic Brackets Cured with Light-emitting Diode and High-intensity Light-emitting Diode. J Contemp Dent Pract 2022; 23 (8):775-780.
Aim: The aim was to find out whether the light-tip distance affected the shear bond strength of orthodontic brackets when cured with light-emitting diode (LED) and high-intensity LED at four different light-tip distances.
Materials and methods: Extracted human premolars were divided into eight groups. Each tooth was embedded in the self-cure acrylic resin block, and brackets were bonded and cured with different lights and different distances. Shear bond strength tests were performed in vitro using the universal testing machine. Data were analyzed using one-way ANOVA test.
Results: The descriptive statistics for shear bond strength of orthodontic brackets cured with LED light at 0 mm was 8.49 ± 1.08 MPa, at 3 mm was 8.13 ± 0.85 MPa, 6 mm was 6.42 ± 0.42 MPa, and at 9 mm was 5.24 ± 0.92 MPa, and those cured with high-intensity light at 0 mm was 19.23 ± 4.83 MPa, at 3 mm was 17.65 ± 3.28 MPa, at 6 mm was 13.04 ± 2.36 MPa, and at 9 mm was 11.74 ± 1.4 MPa. Mean shear bond strength was found to decrease as the light-tip distance increased with both light sources.
Conclusion: Shear bond strength is higher when the light source is close to the surface to be cured, and it decreases as the distance increases. The highest shear bond strength was achieved with high-intensity light.
Clinical significance: Light-emitting diode or high-intensity units can be used for bonding orthodontic brackets without compromising the shear bond strength of the brackets, and that shear bond strength is stronger when the light source is close to the surface to be cured, and it decreases as the distance increases between the light source and the surface.
Jain A, Ray S, Mitra R, et al. Light cure tip distance and shear bond strength: Does it have any clinical significance? J Ind Orthod Soc 2013;47(3):135–142. DOI: 10.5005/jp-journals-10021-1145.
Fleming PS, Eliades T, Katsaros C, et al. Curing lights for orthodontic bonding: a systematic review and meta-analysis. Am J Orthod Dentofacial Orthop 2013;143(4 Suppl):S92–103. DOI: 10.1016/j.ajodo.2012.07.018.
Mills RW, Jandt KD, Ashworth SH. Dental composite depth of cure with halogen and blue light emitting diode technology. Br Dent J 1999;186(8):388–391. DOI: 10.1038/sj.bdj.4800120.
Nakamura S, Mukai T, Senoh M. Candela-class high brightness InGaN/AlGaN double heterostructure blue-light-emitting diodes. Appl Phys Lett 1994;64(13):1687–1689. DOI: 10.1063/1.111832.
Ilie N, Felton K, Trixner K, et al. Shrinkage behaviour of a resin-based composite irradiated with modern curing units. Dent Mater 2005;21(5):483–489. DOI: 10.1016/j.dental.2004.08.007.
Ozturk B, Ozturk AN, Usumez A, et al. Temperature rise during adhesive and resin composite polymerization with various light curing sources. Oper Dent 2004;29(3):325–332. PMID: 15195734.
Lindberg A, Peutzfeldt A, van Dijken JW. Effect of power density of curing unit, exposure duration, and light guide distance on composite depth of cure. Clin Oral Investig 2005;9(2):71–76. DOI: 10.1007/s00784-005-0312-9.
Cacciafesta V, Sfondrini MF, Scribante A, et al. Effect of light-tip distance on the shear bond strengths of composite resin. Angle Orthod 2005;75(3):386–391. DOI: 10.1043/0003-3219(2005)75[386:EOLDOT]2.0.CO;2.
Oyama N, Komori A, Nakahara R. Evaluation of light curing units used for polymerization of orthodontic bonding agents. Angle Orthod 2004;74(6):810–815. DOI: 10.1043/0003-3219(2004)074<0810:EOLCUU>2.0.CO;2.
Artun J, Bergland S. Clinical trials with crystal growth conditioning as an alternative to acid-etch enamel pretreatment. Am J Orthod 1984;85(4):333–340. DOI: 10.1016/0002-9416(84)90190-8.
Newman GV. Epoxy adhesives for orthodontic attachments. Progress report. Am J Orthod 1965;51(12):901–903. DOI: 10.1016/0002-9416(65)90203-4.
Rueggeberg FA, Jordan DM. Effect of light-tip distance on polymerization of resin composite. Int J Prosthodont 1993;6(4):364–370. PMID: 8240647.
Di Nicoló R, Araujo MA, Alves LA, et al. Shear bond strength of orthodontic brackets bonded using halogen light and light-emitting diode at different debond times. Braz Oral Res 2010;24(1):64–69. DOI: 10.1590/s1806-83242010000100011.
Sakaguchi RL, Ferracane JL. Effect of light power density on development of elastic modulus of a model light-activated composite during polymerization. J Esthet Restor Dent 2001;13(2):121–130. DOI: 10.1111/j.1708-8240.2001.tb00434.x.
Aguiar FH, Lazzari CR, Lima DA, et al. Effect of light curing tip distance and resin shade on microhardness of a hybrid resin composite. Braz Oral Res 2005;19(4):302–306. DOI: 10.1590/s1806-83242005000400012.
Felix CA, Price RB. The effect of distance from light source on light intensity from curing lights. J Adhesive Dent 2003;5(4):283–291. PMID: 15008335.
Barakah H. Effect of different curing times and distances on the microhardness of nanofilled resin-based composite restoration polymerized with high-intensity LED light curing units. Saudi Dent J 2021;33(8):1035–1041. DOI: 10.1016/j.sdentj.2021.05.007.