Effect of Curing Light and Restoration Location on Energy Delivery

Objectives: This study determined how long it would take skilled operators to deliver 16J/cm² to an anterior or a posterior restoration using different light curing units (LCUs).

Methods: Two skilled operators used the following LCUs at two locations in the MARC-patient simulator(BlueLight analytics):Optilux 501(Kerr) standard mode for 20s, Sapphire(Den-Mat) for 5 s, Elipar S10(3M ESPE) for 5s and 20 s, DemiPlus(Kerr) standard mode for 5s, SmartLite Max (Dentsply) boost mode for 5s and continuous mode for 20s, RadiiPlus(SDI) for 30 s, Valo(Ultradent) Mains in standard mode for 20s and plasma mode for 3s, Valo Cordless in standard mode for 20s and plasma mode for 3s. The two MARC-trained operators made thirty readings with each light over seven days. The energy (J/cm²) delivered to the anterior Class III and Posterior Class I simulated restorations in MARC was recorded using a laboratory grade spectroradiometer and the time each light would take to deliver 16J/cm² calculated. ANOVA and Fisher's PLSD tests compared differences in the time to deliver 16J/cm² of energy, α=0.05.

Results: Three-way ANOVA showed there was no significant difference between the operators, but there was a difference between the lights and locations. The Valo Mains and Valo Cordless in the plasma mode delivered 16J/cm² in the shortest time at both locations. The Radii Plus took the longest to deliver 16J/cm², taking twice as long in the posterior location.

	Anterior: 1mm Deep Class III		Posterior: 4 mm Deep Class I
Curing Light, Mode and Time	Mean Time (s) to Deliver 16J/cm2	S.D. (s)	Mean Time (s) to Deliver 16J/cm2	S.D. (s)
VALO  C, plasma 3s	5 A	0.3	6 F	0.3
VALO M, plasma 3s	6 A	0.3	6 F	0.5
Sapphire, std. 5s	9 B	0.2	9	0.7
Demi Plus, std. 5s	9 B, C	0.6	12 G	1.0
Elipar S10, std.20s	10 C	1.2	11 G	0.6
Elipar S10, std. 5s	10 C	1.3	12 G	1.3
SmartLiteMax, boost 5s	11 D	1.5	19	3.1
Optilux 501, std. 20s	12 D	1.1	15	1.6
VALO C, std. 20s	12 D	0.8	13 H	0.7
VALO M, std. 20s	14 E	0.8	13 H	0.5
SmartLite Max, cont. 20s	14 E	1.9	25	5.6
Radii Plus, std. 30s	14 E	2.4	28	2.4

Values in each column not significantly different indicated by ^{superscript letter}: Fisher's PLSD α=0.05

Conclusions: Depending on the location of the restoration, some curing lights can take twice as long to deliver the same amount of energy.  Manufacturers of some LCUs could help clinicians to deliver the energy required to cure the selected resin by adjusting the curing times depending on the location and distance to the resin.

Dalhousie and Tufts Universities supported this research.