| Full text | |
| Author(s): |
de Oliveira, D. C. R. S.
[1]
;
Rocha, M. G.
[1]
;
Correr, A. B.
[1]
;
Ferracane, J. L.
[2]
;
Sinhoreti, M. A. C.
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Restorat Dent, Piracicaba, SP - Brazil
[2] Oregon Hlth & Sci Univ, Dept Restorat Dent Sch Dent, Portland, OR 97201 - USA
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Operative Dentistry; v. 44, n. 4, p. 365-378, JUL-AUG 2019. |
| Web of Science Citations: | 0 |
| Abstract | |
Light activation is an important clinical step for achieving success in restorative procedures. This study evaluated the influence of beam profile from different light emission tip types of multiwave light-emitting diodes (LEDs) on the curing profile of resin-based composites. Experimental composites were produced containing either camphorquinone (CQ) or diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) as a photoinitiator. Multiwave LEDs with either a bundle light guide tip (Bluephase G2, Ivoclar Vivadent) or a microlens tip (VALO Cordless, Ultradent) were characterized using a beam profiler. Block-shaped samples (5X5X3 mm depth) of the two composites were cured in a custom-designed mold with the multiwave LEDs positioned to compare the regions exposed to the 420-495 nm (blue) and 380-420 nm (violet) emittances. To map the curing profile, the degree of conversion (DC) of longitudinal thin cross sections from each block was evaluated using transmission FT-NIR. Radiant exposure transmitted through the composites during curing was evaluated at different thicknesses. Data were analyzed using analysis of variance and Tukey test (alpha=0.05; `'beta=0.2). The results indicated that there were differences in the beam profile and the overall radiant exposures transmitted through the composites using each multiwave LED (p<0.01, df=1 F=73.18). However, there were no differences in the curing profiles provided by the two multiwave LEDs (p=0.89, df=12 F=0.52), and similar effects were found according to the different LED emittance regions (p =0.09, df=5, F=2.11). When considering up to 1 mm in depth, no differences in the DC were found between the composites containing either photoinitiators. Starting at 2 mm in depth, the composite containing TPO showed a decrease in DC in the 420-495 nm emittance region, while the composite containing CQ showed a similar decrease in cure efficiency only at 3-mm depth under both 380-420 nm and 420-495 nm emittance regions. Thus, despite the fact that the nonuniform light beam emitted from the two multiwave LEDs was visually distinctly different when delivering 24 J/cm(2), this difference did not seem to affect the curing profile of the composites. However, light transmission within 380-420 nm seems to be reduced with depth, directly affecting the curing profile of composites containing a photoinitiator with absorbance falling within this emission range. (AU) | |
| FAPESP's process: | 17/22195-9 - Development and characterization of bulk fill composites light cured using silver nanoparticles surface plasmon resonance as a photoinitiator system |
| Grantee: | Mateus Garcia Rocha |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate |
| FAPESP's process: | 16/06019-3 - PHYSICOCHEMICAL PROPERTIES AND WEAR RESISTANCE OF COMMERCIAL AND EXPERIMENTAL BULKFILL DENTAL COMPOSITES BASED ON ELASTOMERIC MONOMER |
| Grantee: | Mateus Garcia Rocha |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 16/05823-3 - LOW INTENSITY LIGHT-CURING UNITS AND PHOTOINITIATION SYSTEMS ACTIVATED UNDER WAVELENGHS IN BETWEEN 495-750 NM FOR DENTAL RESIN MATERIALS |
| Grantee: | Dayane Carvalho Ramos Salles de Oliveira |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 14/03028-6 - Optical properties and kinetics of conversion of dental composites made with alternative photoinitiator systems and cured with different light curing units |
| Grantee: | Dayane Carvalho Ramos Salles de Oliveira |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate |
| FAPESP's process: | 17/22161-7 - Development and characterization of dental resin materials photoactivated under WAVELENGHS between 495 and 750 nm |
| Grantee: | Dayane Carvalho Ramos Salles de Oliveira |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |
| FAPESP's process: | 13/04241-2 - The influence of the photoinitiator system and reducing agents on physical properties of experimental resins photoactivated by LEDs |
| Grantee: | Dayane Carvalho Ramos Salles de Oliveira |
| Support Opportunities: | Scholarships in Brazil - Doctorate |