Abstract
Objective: To evaluate the influence of alternative photoinitiators present in composite resins related to yellowing, color stability, photosensitivity, light-curing efficiency, degree of conversion, and microhardness. Materials and methods: The literature was reviewed by two independent reviewers at PubMed. The search strategy was carried out using the following descriptors: (Photoinitiators, dental) AND (Curing lights, dental) AND (Composite Resins) NOT (Case report). The electronic search was carried out until March 2019, without language restrictions, and inclusion and exclusion criteria were applied in the selection. Results: Thirteen articles met the previously established criteria, and all were included. Of these, most were in vitro studies. After the aging of the composite, all systems suffered yellowing, however the isolates with camphorquinone were the most affected and, although there is a greater tendency to yellowing, this does not directly affect color stability. However, the literature is still conflicting about which system has significant color stability. Regarding photosensitivity, all photoinitiators have different absorption peaks. In this sense, the photopolymerization must be chosen with caution, as the conversion of monomers and microhardness proved to be directly linked to the correct combination of photoactivator and photopolymerizing unit. Conclusion: Alternative photoinitiators have a lower yellowing rate and good color stability. They can be up to five times more sensitive than systems containing isolated camphorquinone. Only third-generation light-emitting diodes photopolymerize satisfactorily composite resins that have alternative photoinitiators in their composition, ensuring a good degree of conversion and acceptable Knoop microhardness values.
Highlights
Self-perception of dental aesthetics has become common in people seeking a harmony relation to the face
In vitro studies and literature reviews were considered according to the following inclusion criteria: (a) In vitro research using resins composed of the types of photoinitiators explicit in their composition. (b) In vitro research using bovine dental elements for testing; and (c) Research evaluating physical, mechanical and/or other characteristics of composite resins that contained alternative photoinitiators present
It is known that amines will form byproducts from their photo decomposition, causing discoloration with a tendency of yellow to red/brown color under the action of light or heat (Alvim, et al, 2007, Llie & Hickel, 2008) So TPO, BAPO and mono-alkylphosphine oxide (MAPO) based composites acquire higher color stability compared to conventionals (Silva, et al, 2011)
Summary
Self-perception of dental aesthetics has become common in people seeking a harmony relation to the face. Manufacturers have been replacing or inserting CQ alternative photoinitiators (AP), such as type I photoinitiators, which means that they do not need a coinitiator molecule to generate free radicals and are capable of generating these radicals from the cleavage of the molecule itself Examples of this photoinitiators are 1,2phenylpropanodione (PPD) and acylphosphine oxides: mono-alkylphosphine oxide (MAPO), diphenyl-2,4,6-trimethylbenzoyl phosphine oxide (Lucirin TPO) derived from MAPO, phenylbis(acyl) phosphine oxide BAPO, and 4-propiphenyl-bis (2,6-dichlorobenzoyl) phosphine oxide or called Igarcure 819. These compounds have white coloration, perfectly suitable to be applied for restore whitening teeth (Vervliet, et al 2018, Oliveira, et al, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
