The effect of temperature change on fluoride uptake from a mouthrinse by enamel specimens.

Objective: The aim of this study was to examine the effect of temperature on fluoride uptake by enamel specimens from a 0.05% NaF-fluoridated mouthrinse (Oral-B Advantage; Oral-B Laboratories, Newbridge, UK).

Methods: Enamel specimens were prepared from extracted human maxillary central incisors.

Effect of LED curing modes on the microleakage of a pit and fissure sealant.

Purpose: To evaluate in vitro the curing effect of a very high intensity light-emitting diode (LED) unit and a conventional LED unit (including "soft-start" modes) on the microleakage of a pit and fissure sealant.

Methods: 120 intact caries-free human molars were randomly divided into six groups (n=20), sealed with Fissurit-F and polymerized using either a conventional halogen unit (Optilux) (Control group) in standard mode (40 seconds @ 600 mW/cm2); a very high intensity LED unit (Mini LED) in fast (10 seconds @ 1,100 mW/cm2) or soft-start mode (pulse mode: ten 1-second flashes @ 1,100 mW/cm2; exponential mode: exponential increase from 0 to 1,100 mW/cm2 within 10 seconds followed by 10 seconds @1,100 mW/cm2); or a conventional LED unit (Elipar Freelight) in standard (40 seconds @ 400 mW/cm2) or exponential mode (exponential increase from 0 to 400mW/cm2 within 12 seconds followed by 28 seconds @ 400 mW/cm2). Restored specimens were stored in distilled water at 37 degrees C for 24 hours.

Effect of thermocycling on microleakage of resin composites polymerized with LED curing techniques.

Objective: To evaluate the effect of thermocycling on microleakage of cervical cavities restored with hybrid and flowable resin composites polymerized with 3 different light-emitting diode (LED) curing techniques.

Method And Materials: A total of 120 wedge-shaped cervical cavities were prepared on the buccal surfaces of human molars, restored with hybrid resin composite (Z250, 3M Espe) or with flowable resin composite (Filtek Flow, 3M Espe), and cured with either an LED standard light, an LED high-intensity light, or an LED exponential mode, which is a kind of soft-start curing method. The teeth in each group were divided randomly into 2 subgroups: (1) thermocycling for 1,000 cycles at 5 degrees C and 55 degrees C with a dwell time of 60 seconds, and (2) no thermocycling treatment.

Time-based elution of TEGDMA and BisGMA from resin composite cured with LED, QTH and high-intensity QTH lights.

This study measured the elution of TEGDMA and BisGMA monomers from hybrid, micro-filled resin composites over 72 hours at different time intervals after polymerization with standard quartz-tungsten-halogen (QTH), high-intensity fast-curing QTH and standard blue light emitting diode (LED) light units. Samples were polymerized from the top and bottom surfaces, then immersed in methanol. High performance liquid chromatography (HPLC) was used to measure the amount of monomers released from the samples at various time intervals, ranging from 0 to 72 hours (0, 3, 6, 9, 12, 24, 48 and 72 hours).

The effects of soft-start vs continuous-light polymerization on microleakage in Class II resin composite restorations.

Purpose: Despite the different light sources and polymerization techniques developed to eliminate it, microleakage of resin composite still remains a problem. This in vitro study was designed to compare the effects of exponential mode soft-start polymerization with those of standard and high-intensity continuous light polymerization on microleakage in Class II resin composite restorations.

Materials And Methods: Standardized Class II cavities (4 mm wide, 4 mm long, 5 to 6 mm high, 2 mm deep) were prepared in 50 extracted human molars.