Allen J. Job

Abstract

PURPOSE: To compare the effectiveness of a Gallium Aluminum Arsenide (GaAlAs) diode laser and a light emitting diode (LED) on periodontal ligament fibroblast cell proliferative rates.

METHODS and MATERIALS: PDLF obtained from freshly extracted permanent teeth were cultured under standard conditions until a subconfluent monolayer was present. The next section took 5 days to complete. On day 1, the initial cell concentration of 700 uL/cm2 was plated on 96-well assay plates and placed in a CO2 incubator at 37° C for 24 hours. On day 2, cell counts were first verified using hemocytometry then were irradiated using an 810 nm diode laser emitting 4 Joules/cm2, 8 Joules/cm2, and 12 Joules/cm2 when set at 0.5 W for 10 seconds, 20 seconds, and 30 seconds, respectively. These values corresponded to one light therapy session (T1), two light therapy sessions (T2), and three light therapy sessions (T3). A sample size of 18 was used for each light therapy setting. Concurrently, another batch of cells were irradiated using a LED device with a fixed peak wavelength of 670 nm (650-950 nm range) emitted 4 Joules/cm2, 8 Joules/cm2, and 12 Joules/cm2 88 seconds (T1), 176 seconds (T2), and 264 seconds (T3). A sham control assay plate was also used. Day 3 involved irradiated a second new batch of PDLF cells and the previous day's PDLF cells. Day 4 involved irradiating a third new batch of PDLF cells, the second batch of cells, and the first batch of cells. A 24-hour period of incubation was maintained between each day's irradiation. In total, 3 irradiation exposure days were administered to with laser and LED for T0, Tl, T2, and T3 light therapy sessions. The proliferative rates of PDFL cells were measured on Day 5 using MTS assay technique. Proliferation, expressed in light absorbance at 490 nm, was determined after 1 exposure day, 2 exposure days, and 3 exposure days.

RESULTS: The Mann-Whitney U-test and Kruskall Wallis Rank test were used to analyze the samples, with a significance set at α = 0.05. The laser and LED light therapy cells had statistically higher proliferative PDLF cell rates than the controls. For both laser and LED three light therapy sessions (T3) provided the greatest proliferation rate when two or more exposure days are utilized. Laser therapy provided more statistically higher proliferative rates than LED for 42%. LED therapy provided statistically higher proliferative rates than laser for 16%. While there was no statistical difference for the remaining 42%, comparing laser and LED.

CONCLUSION: A positive effect on PDLF proliferation rates was obtained using both the laser and the LED.

LLU Discipline

Pediatric Dentistry

Department

Pediatric Dentistry

School

Graduate School

First Advisor

John Peterson

Second Advisor

James Kettering

Third Advisor

Jay Kim

Fourth Advisor

Wesley Okumura

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2005

Date (Title Page)

9-2005

Language

English

Library of Congress/MESH Subject Headings

Periodontal Ligament -- growth and development; Fibroblast -- cytology -- metabolism; Lasers -- adverse effects; Lasers -- therapeutic use

Type

Thesis

Page Count

x; 41

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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