FACTORS AFFECTING LIGHT TRANSMISSION OF SINGLE-USE, PLASTIC LIGHT-CURING TIPS

Recently, manufacturers introduced presterilized, single-use, plastic light-curing tips to be used either routinely or on patients with know n or questionable communicable health concerns. The purpose of this st udy was to examine the effect of these single-use tips on night transm ission compared to conventional fiber-optic bundles in a variety of co mmercial light-curing units. Also, the effects of surface contact with the plastic tips (human tissues, reflective or opaque media, and barr ier films) were evaluated. Where applicable, single-use tips from two sources (Caulk/Dentsply and Demetron) were placed in commercial curing units (Optilux 150 and 500, MAX 100, Spectrum Curing Light, and 3M XL -3000), and the intensity was compared to that of the conventional gla ss curing tip used with that specific curing unit. Intensity readings were also made for 6 continuous minutes using plastic tips in a high-i ntensity curing unit to simulate veneer bonding. If the sides of the p lastic tip came in contact with the operator's fingers or the patient' s tongue and/or cheek during a clinical procedure, a lowering of trans mitted light intensity resulted. The glow emitted from the sides of th e tip when in use may be annoying to the operator. To prevent this gla re, the operator may be tempted to treat the sides of the tip by paint ing, applying a thin polymer barrier, abrasion, or wrapping in an opaq ue reflective material(aluminum foil). A significant decrease in light intensity can result if plastic curing tips contact oral tissues or b are hands. Application of thin polymer barriers was found to significa ntly reduce light transmission value., Also, surface modification (coa ting with paint or surface scratches) was found to greatly reduce ligh t intensity levels, while wrapping the tip in aluminum foil produced a very small increase. Results indicated that transmitted light intensi ty with use of plastic tips was dependent upon both the brand of plast ic tip tested and the different photocuring units. Either a slight inc rease or a slight decrease in intensity was noted. Plastic tips did no t degrade in transmitted intensity when exposed to the heat produced d uring a simulated veneering scenario.In summary, use of plastic, singl e-use light-curing tips can provide adequate intensity for photoactiva ted restorative techniques; however, the clinician must be aware of sp ecific, clinically relevant limitations with their use. Clinicians mus t also ps are not designed for re-use.