720 Total Energy Delivered to a Restoration Under Simulated Clinical Conditions

Friday, March 5, 2010: 10:45 a.m. - 12:15 p.m.
Location: Room 150B (Walter E. Washington Convention Center)
Presentation Type: Oral Session
M. MCLEOD, R.B. PRICE, and C.M. FELIX, Dalhousie University, Halifax, NS, Canada

Objectives: This study measured the total energy delivered by four LED-curing lights to tooth preparations in a dental mannequin.

Methods: A device (MARC) has been developed to measure the irradiance delivered from a curing light to a tooth in a mannequin head. MARC software calculates the amount of light energy delivered to the sensors in the teeth. After obtaining appropriate Ethics Committee approval, 10 final year dental students and 10 dentists light cured Class I and Class V simulated restorations in the mannequin head. Lights A, B and C were all used for 10s, light D was used in Plasma mode for 6s. The subjects were told to position the mannequin head as they would for a patient and then to cure the Class I restoration in tooth #1.7 and then the Class V in the #3.7 for the set amount of time. The mouth opening was fixed at 43mm at the incisors and the Class V represented a difficult to reach restoration. The total energy/unit area (J/cm2) delivered to the restorations by the two groups of operators and four lights were compared with ANOVA and Fisher's PLSD α=0.01.

Results: There was no significant difference between the amounts of energy that dentists and students delivered (p>0.01), but there was a wide range in the amount of energy delivered, from 2.6 to 17.4 J/cm2. There was a significant difference in the energy delivered by the four lights, and between the energy delivered to the Class I and Class V locations (p<0.01).

Class I

Class V

Curing Light

Mean±S.D. Energy

J/cm2

Range

J/cm2

Mean±S.D. Energy

J/cm2

Range

J/cm2

A

9.9 ± 2.4

3.5-12.3

10.5 ± 2.4

6.1-14.2

B

10.4 ± 2.2

6.4-13.7

7.4 ± 2.5

2.6-11.7

C

12.2 ± 1.8

6.8-14.5

8.4 ± 2.2

3.9-10.8

D

16.4 ± 3.1

8.8-20.4

12.5 ± 4.0

4.4-17.4

Conclusions: Faculty and students delivered equivalent amounts of energy, but there was a wide range in the amount of energy delivered by the 20 operators to the simulated restorations. Less energy was delivered to the difficult to reach the Class V preparation.

This research was supported by Springboard Atlantic and Dalhousie University.


Keywords: Curing lights, Education research, Effectiveness and Polymerization