Light curing time reduction: in vitro evaluation of new intensive light-emitting diode curing units

• Published in: European journal of orthodontics Vol. 27; no. 4; pp. 408 - 412
• Main Authors: Mavropoulos, A., Staudt, C. B., Kiliaridis, S., Krejci, I.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-08-2005; Oxford Publishing Limited (England)
• Subjects: Animals; Bisphenol A-Glycidyl Methacrylate - chemistry; Bisphenol A-Glycidyl Methacrylate - radiation effects; Cattle; Dental Bonding - instrumentation; Dental Bonding - methods; Dental Enamel - chemistry; Dental Enamel - radiation effects; Dentistry; In Vitro Techniques; Incisor; Light; Lighting - instrumentation; Orthodontic Brackets; Polymers - chemistry; Polymers - radiation effects; Random Allocation; Resin Cements - chemistry; Resin Cements - radiation effects; Stress, Mechanical; Time Factors
• ISSN: 0141-5387; 1460-2210
• DOI: 10.1093/ejo/cji021

The aim of the present in vitro study was to establish the minimum necessary curing time to bond stainless steel brackets (Mini Diamond Twin™) using new, intensive, light-emitting diode (LED) curing units. Seventy-five bovine primary incisors were divided into five equal groups. A standard light curing adhesive (Transbond™ XT) was used to bond the stainless steel brackets using different lamps and curing times. Two groups were bonded using an intensive LED curing lamp (Ortholux™ LED) for 5 and 10 seconds. Two more groups were bonded using another intensive LED curing device (Ultra-Lume™ LED 5) also for 5 and 10 seconds. Finally, a high-output halogen lamp (Optilux™ 501) was used for 40 seconds to bond the final group, which served as a positive control. All teeth were fixed in hard acrylic and stored for 24 hours in water at 37°C. Shear bond strength (SBS) was measured using an Instron testing machine. Weibull distribution and analysis of variance were used to test for significant differences. The SBS values obtained were significantly different between groups (P < 0.001). When used for 10 seconds, the intensive LED curing units achieved sufficient SBS, comparable with the control. In contrast, 5 seconds resulted in significantly lower SBS. The adhesive remnant index (ARI) was not significantly affected. A curing time of 10 seconds was found to be sufficient to bond metallic brackets to incisors using intensive LED curing units. These new, comparatively inexpensive, curing lamps seem to be an advantageous alternative to conventional halogen lamps for bonding orthodontic brackets.