Sample Preparation Sample Measurement
Sample Measurement
Purpose: To determine the effective
Results: The Bluephase 20i cured to 2-
cure times for various high intensity curing units and the corresponding thermal change on a simulated tooth
mm depth in all specimens at 20s. None of the high-intensity lights cured to 2mm depth with a curing time of 3 seconds. Experimental cure times to obtain 80% hardness ratio at 2mm: Cybird – 9 secs, S.P.E.C. 3 - 12 secs. Valo – 9 secs. Flashmax - 12 secs.
Background: The Exposure Reciprocity theory has been utilized by light-curing unit manufacturers to justify marketing products featuring increased light intensity to decrease overall cure time. Several high intensity units on the market claim 1-3 second cure times for a 2mm cure depth. Curing at manufacturer times may produce undercuring while repeated exposures may cause thermal pulpal damage.
Conclusions: Rapid high-intensity light
BluePhase
Cybird XD
S.P.E.C. 3 LED
Sample Preparation
Methods: A simulated 3mm deep proximal slot was prepared in an extracted human molar. Esthet-X HD composite (A2) (Dentsply) was placed in the preparation and light cured. The composite specimens were removed and tested for Knoop hardness (KHN) occlusal-gingivally along the intaglio surface at 0.5-mm increments. A Bluephase 20i (Ivoclar Vivadent) curing light (High setting – 20 sec) was used as the control. High-intensity lights (Cybird, Dentazon; S.P.E.C. 3 LED, Coltene; Valo, Ultradent; Flashmax P3, CMS Dental) were examined at their maximum irradiance settings. Curing times were increased until composite cured to 80% of maximum hardness at a 2-mm depth.
Figure 1
Valo
Flashmax P3
https://www.slideshare.net/WaqasAbi d7/difference-between -rockwell-brinell-vickers-and-knoophardness-test
curing appears inadequate to cure to a 2mm depth of the composite. The theory of exposure reciprocity cannot be reproduced for such short cure times, even with extremely high irradiance.
The need to increase the exposure time not only decreases the purported benefits of rapid light curing but also potentially places the pulp at greater risk for thermal injury and possible necrosis..
Future Research: Simulated intrapulpal temperatures using the same tooth preparation and sample composite will be recorded with an embedded Ktype thermocouple at the cure times previously found for each individual high intensity curing unit.
Purpose: To determine the effective
Results: The Bluephase 20i cured to 2-
cure times for various high intensity curing units and the corresponding thermal change on a simulated tooth
mm depth in all specimens at 20s. None of the high-intensity lights cured to 2mm depth with a curing time of 3 seconds. Experimental cure times to obtain 80% hardness ratio at 2mm: Cybird – 9 secs, S.P.E.C. 3 - 12 secs. Valo – 9 secs. Flashmax - 12 secs.
Background: The Exposure Reciprocity theory has been utilized by light-curing unit manufacturers to justify marketing products featuring increased light intensity to decrease overall cure time. Several high intensity units on the market claim 1-3 second cure times for a 2mm cure depth. Curing at manufacturer times may produce undercuring while repeated exposures may cause thermal pulpal damage.
Conclusions: Rapid high-intensity light
BluePhase
Cybird XD
S.P.E.C. 3 LED
Sample Preparation
Methods: A simulated 3mm deep proximal slot was prepared in an extracted human molar. Esthet-X HD composite (A2) (Dentsply) was placed in the preparation and light cured. The composite specimens were removed and tested for Knoop hardness (KHN) occlusal-gingivally along the intaglio surface at 0.5-mm increments. A Bluephase 20i (Ivoclar Vivadent) curing light (High setting – 20 sec) was used as the control. High-intensity lights (Cybird, Dentazon; S.P.E.C. 3 LED, Coltene; Valo, Ultradent; Flashmax P3, CMS Dental) were examined at their maximum irradiance settings. Curing times were increased until composite cured to 80% of maximum hardness at a 2-mm depth.
Figure 1
Valo
Flashmax P3
https://www.slideshare.net/WaqasAbi d7/difference-between -rockwell-brinell-vickers-and-knoophardness-test
curing appears inadequate to cure to a 2mm depth of the composite. The theory of exposure reciprocity cannot be reproduced for such short cure times, even with extremely high irradiance.
The need to increase the exposure time not only decreases the purported benefits of rapid light curing but also potentially places the pulp at greater risk for thermal injury and possible necrosis..
Future Research: Simulated intrapulpal temperatures using the same tooth preparation and sample composite will be recorded with an embedded Ktype thermocouple at the cure times previously found for each individual high intensity curing unit.
