Indiana University-Purdue University Indianapolis (IUPUI) / Objective: The objective was to assess a multiple emission peak light-emitting-diode
(LED) light-curing unit (LCU) by measuring the polymerization efficiency through the
degree of conversion (DC) and Knoop microhardness (KHN) of a resin-based pit and
fissure sealant at various light curing times and two distances compared to a single
emission peak LED LCU.
Method: Sixty disks of resin-based pit and fissure sealant (Delton, DENTSPLY, York, PA)
samples (6x1mm) were fabricated (n=5/LCU/group). Prepared samples were polymerized
using 10, 20 and 40 second curing time at 2 or 4 mm curing distances. The irradiance and
radiant exposure received on the top/bottom surfaces of the samples were measured using
the Managing Accurate Resin Curing-Resin Calibrator (MARC-RC) system. The samples
were stored at 37°C for one hour. Then, the DC (n=3/surface) and KHN (n=5/surface)
measurements were collected on the top and bottom surfaces using Attenuated Total
Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and a microhardness
tester (Instron) utilizing 25-gm at 10 seconds dwell time, respectively. Multiple-way
ANOVA was performed followed by Tukey test (α=0.05).
Result: The irradiance from the multiple emission peak LED LCU was significantly higher
than the single emission peak LED LCU (1312.6 and 768.3 mW/cm2) respectively.
Moreover, the multiple emission peak LED LCU displayed significantly higher DC
(82.5%) and microhardness (26.2 KHN) compared to the single emission peak LED LCU
(75.5% DC and 21.2 KHN) when curing samples at 2 and 4 mm curing distances assessed
using 10, 20 and 40-second curing times. The 10 second cure at 4 mm showed significantly
lower DC and KHN values compared to the other groups.
Conclusion: The multiple emission peak LED LCU demonstrated significantly higher
irradiance, DC and KHN compared to the single emission peak LED LCU on a resin-based
pit and fissure sealant at 2 and 4 mm curing distances and 10, 20 and 40 second curing
times. Therefore, the multiple emission peak LED LCU performed higher than the single
emission peak LED LCU.
| Identifer | oai:union.ndltd.org:IUPUI/oai:scholarworks.iupui.edu:1805/12286 |
| Date | January 2017 |
| Creators | Alqahtani, Saleh Ali M. |
| Contributors | Soto, Armando E., Platt, Jeffrey A., Cook, Norman Blaine |
| Source Sets | Indiana University-Purdue University Indianapolis |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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