Five-year color changes of light-cured resin composites: influence of light-curing times

1999 ◽  
Vol 15 (4) ◽  
pp. 268-274 ◽  
Author(s):  
Y. Hosoya
10.2341/07-3 ◽  
2007 ◽  
Vol 32 (6) ◽  
pp. 616-622 ◽  
Author(s):  
A. R. Yazici ◽  
Ç Çelik ◽  
B. Dayangaç ◽  
G. Özgünaltay

Clinical Relevance The color stability of resin composites did not vary based on the type of light curing unit. The effect of staining solutions on color changes in resin composites was resin composite and immersion time-dependent.


2012 ◽  
Vol 13 (4) ◽  
pp. 472-475 ◽  
Author(s):  
Arash Poorsattar Bejeh Mir ◽  
Morvarid Poorsattar Bejeh Mir

ABSTRACT Aim Light curing of resin composites may considerably change the color of resin composites. The aim of this study was to evaluate the changing pattern of resin composite's color by different curing times. Materials and methods Fifteen, 1 mm-thick, samples of each A2 shade Clearfill and Filtek P60 composites were prepared. First five samples were cured for 10s (400 mW/cm2) in each pole of the rectangular samples (right upper, right lower, left lower, left upper plus central zone). Consecutive sets of samples, each consists of five, were irradiated by doubling and tripling the curing time to 20 and 30s. Color change were measured by means of CIE 1976 L*a*b system equation (ΔE) for each digitalized picture of the corresponding sample. Results Color of samples was clinically significant changed by increasing the curing time from 10 to 20s and from 20 to 30s for Clearfil (ΔE = 13.86 and 14.11 respectively,) and Filtek P60 (ΔE = 7.68 and 11.66 respectively). The ‘b’ component change was responsible for the most color alteration confirmed by the linear regression model (p < 0.001). Conclusion This study revealed the contrasting pattern of resin composite's color change with the different curing times. Our findings support that light curing is accompanied by a higher attained blue chroma and diminished yellowness of resin composites. Clinical significance A complete and proper curing of sample resin composites on buccal surface of particular tooth, as a common practice to ensure the maximize concordance composite and tooth color, is reassured according to the considerable differences of undercured and overcured in comparison to normocured composite. How to cite this article Poorsattar Bejeh Mir A, Poorsattar Bejeh Mir M. The Effect of Different Curing Time Regimens on Immediate Postpolymerization Color Changes of Resin Composites. J Contemp Dent Pract 2012;13(4):472-475.


RSBO ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 241 ◽  
Author(s):  
Rafael Francisco Lia Mondelli ◽  
Fernanda Cintra Tavares ◽  
Juan Rommel Medina-Valdivia ◽  
Gisele Aihara Haragushiku ◽  
Adilson Yoshio Furuse

Author(s):  
Masato HOTTA ◽  
Yuki MURASE ◽  
Shojiro SHIMIZU ◽  
Shusuke KUSAKABE ◽  
Tomohiro TAKAGAKI ◽  
...  

2020 ◽  
Vol 45 (5) ◽  
pp. 496-505
Author(s):  
CS Sampaio ◽  
PG Pizarro ◽  
PJ Atria ◽  
R Hirata ◽  
M Giannini ◽  
...  

Clinical Relevance Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes. Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro–computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS. Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes. Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.


Author(s):  
Anuradha Vitthal Wankhade ◽  
Sharad Basavraj Kamat ◽  
Santosh Irappa Hugar ◽  
Girish Shankar Nanjannawar ◽  
Sumit Balasaheb Vhate

Introduction: New generation composite resin materials have revolutionized the art of aesthetic dentistry. The clinical success is dependent on effective polymerisation and surface hardness which in turn are dependent on the performance of Light Curing Units (LCU). This study utilises surface hardness as a measure of degree of polymerisation of composite resins achieved by LCUs. Aim: To evaluate the difference in surface hardness of nanohybrid and microhybrid resin composites cured by light curing systems, Light Emitting Diode (LED) and Quartz Tungsten Halogen (QTH). Materials and Methods: In this invitro experimental study, two types of hybrid composites (Nanohybrid and Microhybrid) were tested for surface hardness by using two different light curing systems (LED and QTH). All the Nanohybrid and Microhybrid specimens were cured using LED and QTH LCUs, thus giving four combinations. A total of 60 specimens (6 mm diameter and 2 mm depth) were prepared using Teflon mould with 15 samples for each combination. Surface hardness was measured on upper and lower surface after 24 hours and hardness ratio was calculated. Data was analysed using independent t-test for intergroup comparison. Level of significance was kept at 5%. Results: Surface hardness of resin composites cured by LED LCU was greater than those cured by QTH LCU. Additionally, the hardness value was greater for the upper surface. Nanohybrids showed better surface hardness than Microhybrids for both the LCUs. Conclusion: Nanohybrid composite resins and LED system were found to be more effective in terms of surface hardness as compared to their counterparts.


2008 ◽  
Vol 27 (4) ◽  
pp. 581-589 ◽  
Author(s):  
Ihsan HUBBEZOGLU ◽  
Arife DOGAN ◽  
Orhan Murat DOGAN ◽  
Giray BOLAYIR ◽  
Bulent BEK

2019 ◽  
Vol 30 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Eduardo Haruki Ozera ◽  
Fernanda Miori Pascon ◽  
Américo Bortolazzo Correr ◽  
Regina Maria Puppin-Rontani ◽  
Aline Rogéria de Castilho ◽  
...  

Abstract This study evaluated gloss and color changes of esthetic restorative materials subjected to different acidic beverages. Specimens of resin composites (Z350XT (Z350), IPS Empress Direct (ED), Charisma Diamond (CD)) were prepared and the initial surface gloss and color (ΔE) were measured (n=10). Then, the specimens were immersed in 4 mL of each of the different beverages (cranberry juice; Coca-Cola; coffee or artificial saliva) during 15 min, 3x/day for 14 days and new gloss and color readings were obtained. Color change was evaluated with the ΔE formula and gloss change values were obtained by the formula: (final gloss - initial gloss). Data was submitted to two-way ANOVA followed by Tukey’s post hoc test (a=0.05). CD showed the lowest color change among resin composites. The highest ΔE values were obtained after immersion in coffee and cranberry juice. Coffee promoted the highest gloss change (worst gloss retention), followed by cranberry juice, Coca-cola and artificial saliva (p<0.05). The type of beverage significantly influenced the gloss of resin composites. Coca-cola reduced gloss of the three resin composites in a similar manner. Coffee affected the ED gloss more than that of Z350 and CD, while cranberry juice affected Z350 more than ED and CD. Saliva had a more pronounced effect on the gloss retention of CD than ED. The beverages used in this study influenced the optical surface properties of the composites studied.


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