Effect of light-tip distance on the shear bond strengths of resin-modified glass ionomer cured with high-intensity halogen, light-emitting diode, and plasma arc lights.

Abstract

INTRODUCTION:

The purpose of this study was to assess the effect of light-tip distance on the shear bond strength and the failure site of brackets cured with 3 light-curing units (high-intensity halogen, light-emitting diode, and plasma arc).

METHODS:

One hundred thirty-five bovine mandibular permanent incisors were randomly allocated to 9 groups of 15 specimens each. Stainless steel brackets (Victory Series, Unitek/3M, Monrovia, Calif) were bonded with a resin-modified glass-ionomer (Fuji Ortho LC, GC Europe, Leuven, Belgium) to the teeth, and each curing light was tested at 3 distances from the bracket: 0, 3, and 6 mm. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested for shear bond strength.

RESULTS:

When the 3 light-curing units were compared at a light-tip distance of 0mm, they showed no significantly different shear bond strengths. At a light-tip distance of 3 mm, no significant differences were found between the halogen and plasma arc lights, but both lights showed significantly higher shear bond strengths than the light-emitting diode light. At a light-tip distance of 6 mm, no significant differences were found between the halogen and light-emitting diode lights, but both showed significantly lower bond strengths than the plasma arc light. When the effect of the light-tip distance on each light-curing unit was evaluated, the halogen and light-emitting diode lights showed no significant differences among the 3 distances. However, the plasma arc light produced significantly higher shear bond strengths at a greater light-tip distance. No significant differences were found among the adhesive remnant index scores of the various groups, except with the LED light at a distance of 3 mm.

CONCLUSIONS:

In hard-to-reach areas, the plasma arc curing light is suggested for optimal curing efficiency.

• Authors: Maria Francesca Sfondrini, Vittorio Cacciafesta, Andrea Scribante, Andreas Boehme, Paul-Georg Jost-Brinkmann
• Journal: American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics (Am J Orthod Dentofacial Orthop) Vol. 129 Issue 4 Pg. 541-6 (Apr 2006) ISSN: 1097-6752 [Electronic] United States
• PMID: 16627181 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Acrylic Resins
• Aluminum Silicates
• Fuji Ortho LC
• Glass Ionomer Cements
• Halogens
• Xenon

Topics

• Acrylic Resins (chemistry, radiation effects)
• Aluminum Silicates (chemistry, radiation effects)
• Analysis of Variance
• Animals
• Cattle
• Chi-Square Distribution
• Dental Bonding (methods)
• Dental Equipment
• Dental Stress Analysis
• Glass Ionomer Cements (chemistry, radiation effects)
• Halogens
• Light
• Materials Testing
• Orthodontic Brackets
• Phase Transition
• Random Allocation
• Semiconductors
• Shear Strength
• Technology, Dental (instrumentation)
• Xenon