Evidence Supporting MARC | Bluelight analytics inc.

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Evidence Supporting MARC™

There is a growing base of evidence supporting MARC™ as a clinically relevant laboratory-grade energy measurement tool.

MARC™ is a dental simulator that is used to teach health professionals proper light curing technique.

Dental simulators are widely used in dental education. (Kocher, Riedel et al. 1997; Amer, Omer et al. 1998; Suvinen, Messer et al. 1998; Wright, Taekman et al. 2005; Kanawati, Richards et al. 2009; Le, Scheller et al. 2009; Loomans, Opdam et al. 2009)

Performance on a dental simulator has been shown to predict clinical performance (Formicola, Shub et al. 2002; Stewart, Bates et al. 2004; Stewart, Bates et al. 2005)

MARC™ has been shown to be highly relevant.

The first study, "Quantifying Light Energy Delivered to a Class I Restoration" (Price, Felix, McLeod), was published in the Journal of the Canadian Dental Association:

Purpose: To measure the amount of light energy that dental students actually deliver to a Class I preparation in a dental mannequin.

Materials and Methods: Approval for the study was obtained from the Dalhousie University Health Sciences Research Ethics Board. Each of 20 Third Year dental students light-cured a Class I preparation in tooth 27 in a mannequin head. A photodetector located at the bottom of the cavity preparation measured how much light would be received by a restoration. Each student cured the simulated restoration for 20 seconds using a quartz–tungsten–halogen curing light (Optilux 401). The irradiance received was recorded in real time, and the energy/unit area (J/cm2) delivered by each student to the detector was calculated. The students were then given detailed instructions on how to effectively use the curing light, and the experiment was repeated.

Results: When the curing light was fixed directly over the tooth, the greatest amount of light energy delivered in 20 seconds to the detector was 13.9 ± 0.4 J/cm2. Before instruction, the students delivered between 2.0 and 12.0 J/cm2 (mean ± standard deviation [SD]: 7.9 ± 2.7 J/cm2). After receiving detailed instructions, the same students delivered between 7.7 and 13.4 J/cm2 (mean ± SD: 10.0 ± 1.4 J/cm2). A paired student’s t test showed that instruction resulted in a significant improvement (p < 0.01).

Conclusions: Although instruction yielded improvements, the mean energy delivered was much less (7.9 J/cm2 before instruction and 10.0 J/cm2 after instruction) than the expected 13.9 J/cm2. To maximize the energy delivered, the operator should wear eye protection, should watch what he or she is doing and should hold the light both close to and perpendicular to the restoration.

The second study was presented at the American Association of Dental Research annual conference in Washington, DC in March 2010 and published in the Journal of the Canadian Dental Association (Price RB, Felix CM, Whalen M. Factors Affecting the Energy Delivered to Simulated Class I and Class V Preparations.J Can Dent Assoc 2010;76:a94)

A link to the article (along with accompanying video) can be found here: http://www.jcda.ca/article/a94

The total energy delivered by four LED-curing lights to tooth preparations in a dental mannequin was measured using MARC. 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. 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 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. 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). It was concluded that 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. (McLeod M, Price RB, Felix CM. Total Energy Delivered to a Restoration Under Simulated Clinical Conditions. AADR 2010: Abstract #720)

MARC™ has Been Shown to be Scientifically Accurate

The accuracy of MARC™ was evaluated using four types of commercial curing lights: A Plasma Arc (PAC), Quartz-tungsten-halogen (QTH), single peak LED, and polywave LED curing lights, all used for 10 seconds. Each light was measured five times in random order using MARC™ in a maxillary molar Class I preparation in the mannequin head, and five times using a NIST referenced fiberoptic spectroradiometer system on the laboratory bench. Statistical analyses showed that for these four lights there was no significant difference between the irradiance measurements made by MARC™ or on the laboratory bench. It was concluded that the irradiance and total energy/unit area recorded by MARC™ from these four classes of curing lights was not significantly different from a NIST referenced laboratory based measurement. (Price RB, Felix CM. Accuracy of an Energy Measurement System To Measure Curing Lights. AADR 2010: Abstract #723)

MARC™ Provides Reproducible Results

The reproducibility of MARC™ was determined by measuring the irradiance from one curing light (Bluephase 16i, Ivoclar-Vivadent) was measured fifteen times over a period of three days. Between each recording, the entire set-up was disassembled and recalibrated using two different NIST referenced calibration sources (Cal 1 and Cal 2), and then reassembled. The 10 irradiance values obtained using MARC™ using the two different calibration lamps were then compared to 5 irradiance values measured under controlled laboratory conditions using a NIST referenced spectroradiometer (USB 4000, Ocean Optics). There was no significant difference between the different recordings made using MARC™ in the mannequin head. Although the values obtained from MARC™ were significantly greater than those obtained in the laboratory, the difference was less than 3% (43mW/cm2) and can be attributed to the reflections from the tooth preparation walls. It was concluded that MARC™ can accurately and reproducibly record the irradiance delivered by a curing light to a tooth that is located in a mannequin head. (Lee C, Price RB, Felix CM. Reproducibility of an Intra-Oral Light Energy Measurement Device. AADR 2010: Abstract #722)