289 Comparing Laboratory Practice with Clinical Realities of Dental Light Curing

Thursday, March 21, 2013: 8 a.m. - 9:30 a.m.
Location: Room 611 (Washington State Convention Center)
Presentation Type: Oral Session
D.C. WATTS, School of Dentistry, University of Manchester, Manchester, England, C. FELIX, BlueLight analytics inc, Halifax, NS, Canada, and K.V. CLEARY, Faculty of Engineering, Dalhousie University, Halifax, Canada
Objective: To evaluate the extent to which light ‘energy delivery’ (ED) in J/cm2 is quantified in recent resin based composite (RBC) research and how that ED compared to: (i) the RBC manufacturer’s minimum energy requirement (MMER) and (ii) the ED for RBCs with the same MMER when used in simulated clinical practice.

Method: 100 published RBC research papers, identified via PubMed, from 2010-2012 were examined. The papers were concerned with a wide range of property and performance studies. Papers that reported the ED to light-cure RBCs prior to subsequent evaluations were identified.  The reported ED  was then compared to: (i) the MMER for the RBC, and (ii) the ED by a group of 11 practicing dentists who use a RBC with the same MMER.  The clinical ED of these dentists was assessed using a MARC® Patient Simulator (BlueLight analytics, Halifax, Canada) which uses embedded sensors and a calibrated spectrometer to measure the ED when the clinicians repeated (n=6) simulated photo-curing with 5 generic LCUs.

Result: Light energy delivery was quantified in 54/100 papers.  For 3 papers, ED ranged from 21-98 % of the MMER. A majority of RBC specimens received multiples of the MMER.

# papers






% of MMER


21- 98 %

100 – 150 %

150 – 200 %

 >  200 %

Conversely, intra-oral ED by the set of clinicians ranged overall between 0.5 to 30.5  J.cm-2 (6–381 % of MMER). However 7/11 dentists had  ED<<MMER on several occasions, the incidence being partly dependent on the preferred LCU.

Conclusion: In the set of in vitro studies evaluated, the majority trend was to photo-cure with energy-delivery far in excess of MMER.  By contrast, the clinical energy-delivery examined tended towards far less than the MMER. As previous research has shown the manifold deleterious effects of undercuring, the present in vitro studies highlight the best that can be achieved by photo-curing rather than corresponding to the outcomes of clinical undercuring.

Keywords: Composites, Curing lights, Dental materials and Polymerization