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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effect of Beam Profiles From Different Light Emission Tip Types of Multiwave Light-emitting Diodes on the Curing Profile of Resin-based Composites

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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