Objectives: To compare variation in depth-of-cure (DOC) values between conventional scraping methods and solvent-based tests.
Methods: Compules of a commercial resin composite (A3, Prodigy, Kerr) were modified as cylinders. Composite paste was forced to one end against a Mylar sheet. The distal end of a light curing unit (quartz-tungsten-halogen (Optilux 501); conventional blue LED (LEDemetron 1); high intensity blue LED (DEMI)) was held 2 mm away from the Mylar surface. A variety of exposure durations were applied: 10, 20, 40, or 60s. Compules were dark-stored for 24h, then the content was ejected and treated in one of two manners. “Scraping” consisted of manual removal of unpolymerized paste using a plastic spatula. “Chemical” consisted of sonicating the ejected compule content in ethanol for 20 min. The recovered specimen was then sectioned lengthwise. For each test type, the length of remaining composite was measured. Two measurement types were made on sectioned specimens: “all solvent” measured the entire length of the sonicated specimen while “non-frosty” measured o along the sectioned axis where composite was not frosty. Length measurements were halved (ISO Standard 4049) to generate depths of cure. An exact rank-based test (Conover's test) with mid-P correction was used to compare variability of the depth values among the three methods. Five replications per test grouping were made and all testing was performed at the 0.05 level of significance.
Results: Within each light group, none of the comparisons among the measurement methods were significantly different for any exposure level, with the exception of the 40-s exposure from the Optilux 501 light, where “non-frosty” demonstrated significantly higher variance than either of the other two methods (p = 0.015).
Conclusions: In general, conventional, manual scraping did not demonstrate higher variation in values than either of two methods that relied on chemical solvation techniques.