KACD
Articles
- Page Path
- HOME > Restor Dent Endod > Volume 40(2); 2015 > Article
- Research Article Effect of resin thickness on the microhardness and optical properties of bulk-fill resin composites
-
Eun-Ha Kim1, Kyoung-Hwa Jung1, Sung-Ae Son1, Bock Hur1, Yong-Hoon Kwon2, Jeong-Kil Park1
-
2015;40(2):-135.
DOI: https://doi.org/10.5395/rde.2015.40.2.128
Published online: January 13, 2015
1Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, Korea.
2Department of Dental Materials, School of Dentistry, Pusan National University, Yangsan, Korea.
- Correspondence to Jeong-Kil Park, DDS, MSD, PhD. Associate Professor, Department of Conservative Dentistry, School of Dentistry, Pusan National University, 20, Geumo-ro, Mulgeum-eup, Yangsan, Korea 626-787. TEL, +82-55-360-5221; FAX, +82-55-360-5214; jeongkil@pusan.ac.kr
• Received: July 23, 2014 • Accepted: December 2, 2014
©Copyrights 2015. The Korean Academy of Conservative Dentistry.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
- 287 Views
- 5 Download
- 56 Crossref
Abstract
-
Objectives This study evaluated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites.
-
Methods Four bulk-fill (Venus Bulk Fill, Heraeus Kulzer; SDR, Dentsply Caulk; Tetric N-Ceram Bulk Fill, Ivoclar vivadent; SonicFill, Kerr) and two regular resin composites (Charisma flow, Heraeus Kulzer; Tetric N-Ceram, Ivoclar vivadent) were used. Sixty acrylic cylindrical molds were prepared for each thickness (2, 3 and 4 mm). The molds were divided into six groups for resin composites. The microhardness was measured on the top and bottom surfaces, and the colors were measured using Commission Internationale d'Eclairage (CIE) L*a*b* system. Color differences according to the thickness and translucency parameters and the correlations between the microhardness and translucency parameter were analyzed. The microhardness and color differences were analyzed by ANOVA and Scheffe's post hoc test, and a student t-test, respectively. The level of significance was set to α = 0.05.
-
Results The microhardness decreased with increasing resin thickness. The bulk-fill resin composites showed a bottom/top hardness ratio of almost 80% or more in 4 mm thick specimens. The highest translucency parameter was observed in Venus Bulk Fill. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and translucency parameter according to the thickness.
-
Conclusions Within the limitations of this study, the bulk-fill resin composites used in this study can be placed and cured properly in the 4 mm bulk.
Introduction
Resin composites have improved in terms of the chemical composition and filler reinforcements. Recently, many clinicians have shown the preference for time-saving restorative procedures for posterior resin applications. A new category of resin composites, a bulk-fill resin composite, has been introduced over the past few years. They were developed to speed up the restoration process by enabling up to 4 mm thick increments to be cured in a single step, thereby skipping the time-consuming layering process.
Flowable bulk-fill resin composites (SDR, Smart Dentin Replacement, Dentsply Caulk, Milford, DE, USA; Venus Bulk Fill, Heraeus Kulzer, Hanau, Germany; Filtek Bulk Fill, 3M ESPE, St. Paul, MN, USA) have low-viscosity and easy-handling properties. They have many advantages for use as flowable composites. First, high flowability makes them particularly useful for cavities that are difficult to access. Second, the ability to form layered structures helps reduce air entrapment. Third, the high flexibility makes them useful for liners in the cavity.1 On the other hand, other resin composites in the same category (Tetric N-Ceram Bulk Fill, Ivoclar vivadent, Schaan, Liechtenstein; x-tra fil, VOCO, Cuxhaven, Germany) have high viscosity and high filler content. The handling properties of these composites are similar to regular hybrid composites. Recently, a sonic-activated bulk-fill resin composite (SonicFill, Kerr, Orange, CA, USA) was introduced, and according to the manufacturer instruction, 5 mm thick increments can be placed in a single step.
In a previous study, the modulus of elasticity and hardness of SDR, Venus Bulk Fill and Filtek Bulk Fill were considerably below the mean values measured in the regular nanohybrid and microhybrid resin composites.2 In the same study, the modulus of elasticity and hardness of Tetric EvoCeram Bulk Fill (European trade name of Tetric N-Ceram), SonicFill and X-tra Fil were higher.2 Therefore, flowable bulk-fill resin composites, such as SDR, Venus Bulk Fill and Filtek Bulk Fill require an additional final capping layer made from regular hybrid resin composites, whereas other new resin composites, such as SonicFill, Tetric N-Ceram Bulk Fill and X-tra Fil, can be placed without it.
Although the manufacturers recommend bulk-filling of these materials up to 4 mm, many clinicians suspect that the depth of cure and mechanical properties might not be suitable for clinical use.3 Hardness measurements of the bottom surface can be used to evaluate the depth of cure for resin composites. Because the composition and filler content play important roles in the optical properties of resin composites, the bulk-fill resin composites exhibit different optical properties including excellent translucency parameter compared with regular resin composites.1,4
The manufacturers explain that the higher depth of cure of the bulk-fill resin composites is due to the more potent initiator system or/and higher translucency.4,5 However, few studies have examined translucency and depth of cure of bulk-fill resin composites. Also, there are few reports of the microhardness and optical properties according to resin thickness of these composites. Therefore, this study investigated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites.
Materials and Methods
Four bulk-fill resin composites (Venus Bulk Fill, VB; SDR, SR; Tetric N-Ceram Bulk Fill, TB; SonicFill, SO) and two regular resin composites (Charisma flow, CF; Tetric N-Ceram, TN) were used. CF was used as the control group of flowable bulk-fill resin composites including VB and SR, whereas TN was used as the control group of the non-flowable bulk-fill resin composites including TB and SO. Table 1 lists the other details of the resin composites used in this study.
Table 1
Download Table 
Resin composites used in this study
UDMA, urethane dimethacrylate; EBADMA, ethoxylated bisphenol A dimethacrylate; TEGDMA, triethyleneglycol dimethacrylate; Bis-GMA, bisphenol A diglycidyl ether dimethacrylate.
Sixty acrylic cylindrical molds with a socket, 9 mm in diameter, were prepared for each thickness (2 mm, 3 mm and 4 mm). They were divided into six groups for each resin composite (n = 10). The resin composites were dispensed, manipulated and polymerized on thin glass slides according to the manufacturers' instructions. The top surfaces were then covered with another glass slide to make the surface flat. Polymerization was then carried out using a LED light curing unit (BluePhase, Ivoclar Vivadent Inc., Amherst, NY, USA; light intensity of 1,200 mW/cm2) for 20 seconds in contact with the top surface of the specimens. Subsequently, specimens were stored in water for 24 hours at 37℃ in a dark chamber.
The microhardness of the top (0 mm) and bottom (2 mm, 3 mm and 4 mm) surfaces were measured using a Vickers hardness tester (MVK-H1, Akashi, Tokyo, Japan). Microindentation was carried out using a 200 gf load with a 10 seconds dwell time.
The colors of all specimens were measured with a spectrophotometer (CM-3600d, Minolta, Tokyo, Japan) according to the Commission Internationale d'Eclairage (CIE) L*a*b* relative to the standard illuminant D65 against white background (L* = 93.26, a* = -0.61, and b* = 2.09) and black background (L* = 2.93, a* = 0.38, and b* = -0.34). The black standard was a matt black plate covered with black velvet, and the white standard was a white ceramic. Before measuring each group, the spectrophotometer was calibrated with standard calibrating blocks (white and black) according to the manufacturer's recommendation.
Color change according to thickness is important when using esthetic materials. Thus the color differences (ΔE) according to the thickness were obtained. ΔE23 means ΔE between the 2 mm and 3 mm specimens, and ΔE24 means ΔE between the 2 mm and 4 mm specimens. ΔE23 and ΔE24 were calculated using the following formula:
L* represents the degree of gray corresponding to a lightness, a* is the red (for + a* value)-green (for - a* value) axis, and b* is the yellow (for + b* value)-blue (for - b* value) axis.
The translucency parameter (TP) values were determined by calculating the color difference between readings over the black and white background for the same specimen, using the following formula:
Subscripts 'B' and 'W' refer to the color coordinates over a black and white background, respectively. The differences between TP2mm and TP3mm (ΔTP23) and between TP2mm and TP4mm (ΔTP24) were also calculated.
The microhardness was analyzed by one-way and two-way ANOVA and Scheffe's post hoc test, and the color differences were analyzed using a student t-test. TP was analyzed by one-way ANOVA. The software used was SPSS 15.0 (SPSS Inc., Chicago, IL, USA). The level of significance was set to p < 0.05.
Results
Table 2 lists the mean microhardness in each thickness. Two-way ANOVA revealed that there was significant difference in microhardness according to the type of resin composites and thickness (p < 0.001). As shown in Table 3, two factors (type of resin composites and thickness) as well as their interaction were found to have a significant effect in the microhardness (p < 0.001).
Table 2
Download Table
Microhardness (Hv) for the different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Different superscript letters indicate a statistically significant difference among groups (p < 0.05).
Statistical results: model, p < 0.001; resin composites, p < 0.001; thickness, p < 0.001; interaction effect of resin composites × thickness, p < 0.001.
Table 3
Generalized linear model for comparison of resin composites and thickness, as well as their interaction
Download Table
Figure 1 shows the comparison of microhardness among different thicknesses in each resin composite. For group SR, TB and TN, microhardness decreased significantly with increasing thickness (p < 0.05). For group VB, there were no significant difference in microhardness values among the 2 mm, 3 mm and 4 mm specimens. For group SO, no significant difference was observed between the 2 mm and 3 mm specimens. For group CF, the microhardness of 4 mm sample was significantly lower than the other thicknesses (p < 0.05). Furthermore, the percentage of the bottom to top surface hardness (bottom/top hardness ratio) of the 4 mm specimens for VB, SR, CF, TB, SO, and TN were 94.2%, 87.3%, 60.4%, 78.7%, 84.8% and 52.4%, respectively. The bulk-fill resin composite groups including VB, SR, SO and TB showed a bottom/top hardness ratio of almost 80% or more in the 4 mm thick specimens.
Figure 1
Figure 1
Comparison of microhardness among different thicknesses.
Inverted triangle (▾) indicates no significant difference.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Download Figure
Table 4 lists the CIE L*a*b* color coordinates of the resin composites with different thickness. Table 5 lists the mean ΔE (ΔE23 and ΔE24) values. Among the bulk-fill resin composites, the flowable composites had higher ΔE than the non-flowable composites. VB showed the highest ΔE value. For the regular resin composites (CF and TN), ΔE23 and ΔE24 were significantly different (p < 0.05). In each bulk-fill resin composites, there was a significant difference between ΔE23 and ΔE24 in the flowable composites (p < 0.05), but not in the non-flowable composites (p > 0.05).
Table 4
Download Table
CIE L*a*b* color coordinate values of resin composites with different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Table 5
Download Table
Color difference (ΔE) values for the different thickness
*Student t-test.
ΔE23 means ΔE between 2 mm and 3 mm specimens, and ΔE24 means ΔE between 2 mm and 4 mm specimens.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 2 shows the TP and ΔTP of each group. TP decreased significantly with increasing thickness in all groups (p < 0.05). Among the flowable resin composites, the highest TP was observed in group VB, followed in order by SR and CF. Among the non-flowable resin composites, the highest TP was observed in group TB, followed by SO and TN in all thickness specimens.
Figure 2
Figure 2
Translucency parameter (TP) and ΔTP of each group.
ΔTP23 means the difference between TP2mm and TP3mm, and ΔTP24 means the difference between TP2mm and TP4mm.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Download Figure
Figure 3 shows the correlations between the microhardness and TP according to the resin thickness of each group. In groups SR, CF, TB, SO and TN, the microhardness showed a linear correlation with TP (R: 1.00, 0.89, 0.94, 0.95 and 0.92, respectively) according to thickness, whereas no linear correlation was noted in group VB (R: 0.43).
Figure 3
Figure 3
Correlation between microhardness and TP according to resin thickness.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Download Figure Discussion
In the present study, the flowable bulk-fill resin composites showed lower microhardness than the non-flowable bulk-fill resin composites as shown in a previous study.2 This could be attributed to the lower filler content of the flowable bulk-fill resins. SR showed the highest microhardness among the flowable resin composites, and SO exhibited the highest microhardness among the non-flowable resin composites. These results can also be explained by SR and SO containing more inorganic filler than the other composites in the same category (flowable or non-flowable).
The microhardness of resin composites are affected by the resin composite thickness.6,7 In the present study, the same tendency of the microhardness decreasing as the resin thickness increased was observed. Regarding the amount of the hardness change, bulk-fill resin composites, such as VB, SR, TB and SO exhibited smaller changes in hardness according to the thickness, whereas regular resin composites, such as CF and TN showed a drastic decrease in the 4 mm specimens. The steep decreases in the microhardness of the 4 mm specimens of regular composites in this study are in agreement with a previous study which reported that the resin hardness at the bottom was significantly different from that at the top when the specimens were 4 or 5 mm thick.8 This can be explained by the difference in TP between the bulk-fill and regular composites. With a higher TP, the bulk-fill resin composites allow more light to penetrate deep inside the resin composites, which possibly results in more polymerized monomers at the bottom surface.
The increased depth of cure in bulk-fill resin composites might be due to not only the increased TP, but also to the modified monomers and photoinitiator systems. The manufacturer explains that SR has a substance described as a 'polymerization modulator' embedded chemically in the backbone of the polymerizable resin.9 The polymerization modulator synergistically interacts with the camphorquinone photoinitiator. In the case of TB, the manufacturer states that, besides having a regular camphorquinone/amine initiator system, it has introduced an 'initiator booster' (Ivocerin) that can polymerize the material in depth.2
Several studies3,5,10,11 have used hardness measurements performed on the top and bottom surface of a light-cured resin composite specimen to define the depth of cure. The bottom/top hardness ratio above 80% has often been used as a minimum acceptable threshold. The bulk-fill resin composites used in this study showed a bottom/top hardness ratio of almost 80% or more in the 4 mm thick specimens, which means that these materials can be placed and cured properly in the 4 mm bulk in clinical situations.
The color of the resin composites may be affected by altering the resin thickness.12 According to Inokoshi et al., ΔE < 1 is considered not appreciable by the human eye.13 Values 1 < ΔE < 3.3 are considered appreciable by skilled operators, whereas values of ΔE > 3.3 are considered appreciable by non-skilled persons. In the present study, 2 mm thick specimens of each group were used as the standard to evaluate ΔE according to the thickness. From the result of this study, VB showed the largest ΔE (> 3.3) depending on the resin thickness, which is appreciable by non-skilled persons. In TN, ΔE24 could also be appreciable by non-skilled persons (ΔE > 3.3). Other resin composites showed ΔE values that were only appreciable by skilled operators (1 < ΔE < 3.3).
TP is a parameter that can indicate the translucency of resin composites. The translucency of resin composites depends on their thickness as well as the scattering and absorption coefficients of the resin, filler particles, pigments and opacifiers.14,15,16 In the present study, VB and TN showed the highest and lowest TP, respectively (p < 0.05). Lee reported that TP decreased with increasing amount of filler.17 Campbell et al. reported that as the filler size increased, the TP of the resin composite increased accordingly.18 A significantly high TP in VB could be attributed to similar refraction indices between fillers and matrix resin.1 In another flowable bulk-fill resin composite, SR, the increased TP might be due to the large filler size.2 In TB, a lower inorganic filler content might lead to a high TP. Although TB has the high filler content, it also contains prepolymerized fillers, meaning that the inorganic filler content is consistently lower.3 In SO, despite the high filler content, a large filler size might increase TP. A comparison of the same handling category (flowable or non-flowable) revealed the bulk-fill resin composites to have a higher TP than the regular composites. Regarding the TP changes depending on the resin thickness, Kim et al., and Lassila et al., reported that the translucency of the resin composites increases with decreasing thickness.1,19 In agreement of these studies, the same results were found in all resin composites.
The present study evaluated the correlation between the microhardness and TP according to the resin thickness. The correlation coefficients (R) between the microhardness and TP for VB, SR, CF, TB, SO and TN were 0.43, 1.00, 0.89, 0.94, 0.95 and 0.92, respectively. All resin composites used in this study except for VB showed linear correlations between the microhardness and TP depending on the thickness, meaning that clinicians should be cautious about thickness of resin composites when restoring deep cavities. In VB, the significantly higher TP than the others may allow more light to penetrate deeper up to 4mm, resulting in the similar microhardness among the 2 mm, 3 mm and 4 mm specimens (p > 0.05). This can be also explained by the highest percentage (94.2%) of the bottom/top hardness ratio in 4 mm. Therefore, in VB there was no linear correlation between the microhardness and TP. A comparison of the slopes of the microhardness-TP correlation graph showed that the regular resin composites exhibited gentler slopes than the bulk-fill resin composites (Figure 3). This might be because the decrease in microhardness with increasing thickness is larger in regular resin composites. In contrast, the slopes of the bulk-fill resin composites were steep, which means that the microhardness of the bulk-fill resin composites decreased gradually with increasing resin thickness.
For the restorations with bulk-fill resin composites, the manufacturers recommend that 4 mm thick increments can be cured in a single step. Based on the results of this study, up to 4 mm thick increments of bulk-fill resin composites are clinically acceptable.
Conclusions
The microhardness decreased with increasing resin thickness. The bulk-fill resin composites used in this study showed the bottom/top hardness ratio of almost 80% or more in the 4 mm-thick specimens. The ΔE according to the thickness was greatest in Venus Bulk Fill. TP decreased with increasing resin thickness. Among the flowable resin composites, the highest TP was observed in Venus Bulk Fill, whereas Tetric N-Ceram Bulk Fill showed the highest TP among the non-flowable resin composites. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and TP according to the thickness.
Figure 1
Comparison of microhardness among different thicknesses.
Inverted triangle (▾) indicates no significant difference.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 2
Translucency parameter (TP) and ΔTP of each group.
ΔTP23 means the difference between TP2mm and TP3mm, and ΔTP24 means the difference between TP2mm and TP4mm.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 3
Correlation between microhardness and TP according to resin thickness.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Table 1
Resin composites used in this study
Table 2
Microhardness (Hv) for the different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Different superscript letters indicate a statistically significant difference among groups (p < 0.05).
Statistical results: model, p < 0.001; resin composites, p < 0.001; thickness, p < 0.001; interaction effect of resin composites × thickness, p < 0.001.
Table 3
Generalized linear model for comparison of resin composites and thickness, as well as their interaction
Table 4
CIE L*a*b* color coordinate values of resin composites with different thickness
Table 5
Color difference (ΔE) values for the different thickness
- 1. Lassila LV, Nagas E, Vallittu PK, Garoushi S. Translucency of flowable bulk-filling composites of various thickness. Chin J Dent Res 2012;15:31-35.PubMed
- 2. Ilie N, Bucuta S, Draenert M. Bulk-fill resin-based composites: an in vitro assessment of their mechanical performance. Oper Dent 2013;38:618-625.ArticlePubMedPDF
- 3. Czasch P, Ilie N. In vitro comparison of mechanical properties and degree of cure of bulk fill composites. Clin Oral Investig 2013;17:227-235.ArticlePubMedPDF
- 4. Ilie N, Keßler A, Durner J. Influence of various irradiation processes on the mechanical properties and polymerisation kinetics of bulk-fill resin based composites. J Dent 2013;41:695-702.ArticlePubMed
- 5. Flury S, Hayoz S, Peutzfeldt A, Hüsler J, Lussi A. Depth of cure of resin composites: is the ISO 4049 method suitable for bulk fill materials? Dent Mater 2012;28:521-528.ArticlePubMed
- 6. Tanthanuch S, Ruenqsri P, Kukiattrakoon B. Optimal depth of cure for nanohybrid resin composite using quartz tungsten halogen and new high intensity lightemitting diode curing units. Gen Dent 2013;61:e14-e17.
- 7. Finan L, Palin WM, Moskwa N, McGinley EL, Fleming GJ. The influence of irradiation potential on the degree of conversion and mechanical properties of two bulk-fill flowable resin composite base materials. Dent Mater 2013;29:906-912.PubMed
- 8. Price RB, Dérand T, Loney RW, Andreou P. Effect of light source and specimen thickness on the surface hardness of resin composites. Am J Dent 2002;15:47-53.PubMed
- 9. Ilie N, Hickel R. Investigations on a methacrylate-based flowable composite based on the SDR™ technology. Dent Mater 2011;27:348-355.ArticlePubMed
- 10. Bouschlicher MR, Rueggeberg FA, Wilson BM. Correlation of bottom-to-top surface microhardness and conversion ratios for a variety of resin composite compositions. Oper Dent 2004;29:698-704.PubMed
- 11. Moore BK, Platt JA, Borges G, Chu TM, Katsilieri I. Depth of cure of dental resin composites: ISO 4049 depth and microhardness of types of materials and shades. Oper Dent 2008;33:408-412.ArticlePubMedPDF
- 12. Yeh CL, Powers JM, Miyagawa Y. Color of selected shades of composites by reflection spectrophotometry. J Dent Res 1982;61:1176-1179.ArticlePubMedPDF
- 13. Inokoshi S, Burrow MF, Kataumi M, Yamada T, Takatsu T. Opacity and color changes of tooth-colored restorative materials. Oper Dent 1996;21:73-80.PubMed
- 14. Miyagawa Y, Powers JM, O'Brien WJ. Optical properties of direct restorative materials. J Dent Res 1981;60:890-894.ArticlePubMedPDF
- 15. Johnston WM, Reisbick MH. Color and translucency changes during and after curing of esthetic restorative materials. Dent Mater 1997;13:89-97.ArticlePubMed
- 16. Kim IJ, Lee YK. Changes in color and color parameters of dental resin composites after polymerization. J Biomed Mater Res B Appl Biomater 2007;80:541-546.ArticlePubMed
- 17. Lee YK. Influence of filler on the difference between the transmitted and reflected colors of experimental resin composites. Dent Mater 2008;24:1243-1247.ArticlePubMed
- 18. Campbell PM, Johnston WM, O'Brien WJ. Light scattering and gloss of an experimental quartz-filled composite. J Dent Res 1986;65:892-894.ArticlePubMedPDF
- 19. Kim SJ, Son HH, Cho BH, Lee IB, Um CM. Translucency and masking ability of various opaque-shade composite resins. J Dent 2009;37:102-107.ArticlePubMed
REFERENCES
Tables & Figures
Table 1
Download Table
Resin composites used in this study
UDMA, urethane dimethacrylate; EBADMA, ethoxylated bisphenol A dimethacrylate; TEGDMA, triethyleneglycol dimethacrylate; Bis-GMA, bisphenol A diglycidyl ether dimethacrylate.
Table 2
Download Table
Microhardness (Hv) for the different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Different superscript letters indicate a statistically significant difference among groups (p < 0.05).
Statistical results: model, p < 0.001; resin composites, p < 0.001; thickness, p < 0.001; interaction effect of resin composites × thickness, p < 0.001.
Table 3
Generalized linear model for comparison of resin composites and thickness, as well as their interaction
Download Table
Figure 1
Comparison of microhardness among different thicknesses.
Inverted triangle (▾) indicates no significant difference.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Download Figure
Table 4
Download Table
CIE L*a*b* color coordinate values of resin composites with different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Table 5
Download Table
Color difference (ΔE) values for the different thickness
*Student t-test.
ΔE23 means ΔE between 2 mm and 3 mm specimens, and ΔE24 means ΔE between 2 mm and 4 mm specimens.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 2
Translucency parameter (TP) and ΔTP of each group.
ΔTP23 means the difference between TP2mm and TP3mm, and ΔTP24 means the difference between TP2mm and TP4mm.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Download Figure
Figure 3
Correlation between microhardness and TP according to resin thickness.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Download Figure
Figure 1
Comparison of microhardness among different thicknesses.
Inverted triangle (▾) indicates no significant difference.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 2
Translucency parameter (TP) and ΔTP of each group.
ΔTP23 means the difference between TP2mm and TP3mm, and ΔTP24 means the difference between TP2mm and TP4mm.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 3
Correlation between microhardness and TP according to resin thickness.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Table 1
Resin composites used in this study
Table 2
Microhardness (Hv) for the different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Different superscript letters indicate a statistically significant difference among groups (p < 0.05).
Statistical results: model, p < 0.001; resin composites, p < 0.001; thickness, p < 0.001; interaction effect of resin composites × thickness, p < 0.001.
Table 3
Generalized linear model for comparison of resin composites and thickness, as well as their interaction
Table 4
CIE L*a*b* color coordinate values of resin composites with different thickness
Table 5
Color difference (ΔE) values for the different thickness
REFERENCES
- 1. Lassila LV, Nagas E, Vallittu PK, Garoushi S. Translucency of flowable bulk-filling composites of various thickness. Chin J Dent Res 2012;15:31-35.PubMed
- 2. Ilie N, Bucuta S, Draenert M. Bulk-fill resin-based composites: an in vitro assessment of their mechanical performance. Oper Dent 2013;38:618-625.ArticlePubMedPDF
- 3. Czasch P, Ilie N. In vitro comparison of mechanical properties and degree of cure of bulk fill composites. Clin Oral Investig 2013;17:227-235.ArticlePubMedPDF
- 4. Ilie N, Keßler A, Durner J. Influence of various irradiation processes on the mechanical properties and polymerisation kinetics of bulk-fill resin based composites. J Dent 2013;41:695-702.ArticlePubMed
- 5. Flury S, Hayoz S, Peutzfeldt A, Hüsler J, Lussi A. Depth of cure of resin composites: is the ISO 4049 method suitable for bulk fill materials? Dent Mater 2012;28:521-528.ArticlePubMed
- 6. Tanthanuch S, Ruenqsri P, Kukiattrakoon B. Optimal depth of cure for nanohybrid resin composite using quartz tungsten halogen and new high intensity lightemitting diode curing units. Gen Dent 2013;61:e14-e17.
- 7. Finan L, Palin WM, Moskwa N, McGinley EL, Fleming GJ. The influence of irradiation potential on the degree of conversion and mechanical properties of two bulk-fill flowable resin composite base materials. Dent Mater 2013;29:906-912.PubMed
- 8. Price RB, Dérand T, Loney RW, Andreou P. Effect of light source and specimen thickness on the surface hardness of resin composites. Am J Dent 2002;15:47-53.PubMed
- 9. Ilie N, Hickel R. Investigations on a methacrylate-based flowable composite based on the SDR™ technology. Dent Mater 2011;27:348-355.ArticlePubMed
- 10. Bouschlicher MR, Rueggeberg FA, Wilson BM. Correlation of bottom-to-top surface microhardness and conversion ratios for a variety of resin composite compositions. Oper Dent 2004;29:698-704.PubMed
- 11. Moore BK, Platt JA, Borges G, Chu TM, Katsilieri I. Depth of cure of dental resin composites: ISO 4049 depth and microhardness of types of materials and shades. Oper Dent 2008;33:408-412.ArticlePubMedPDF
- 12. Yeh CL, Powers JM, Miyagawa Y. Color of selected shades of composites by reflection spectrophotometry. J Dent Res 1982;61:1176-1179.ArticlePubMedPDF
- 13. Inokoshi S, Burrow MF, Kataumi M, Yamada T, Takatsu T. Opacity and color changes of tooth-colored restorative materials. Oper Dent 1996;21:73-80.PubMed
- 14. Miyagawa Y, Powers JM, O'Brien WJ. Optical properties of direct restorative materials. J Dent Res 1981;60:890-894.ArticlePubMedPDF
- 15. Johnston WM, Reisbick MH. Color and translucency changes during and after curing of esthetic restorative materials. Dent Mater 1997;13:89-97.ArticlePubMed
- 16. Kim IJ, Lee YK. Changes in color and color parameters of dental resin composites after polymerization. J Biomed Mater Res B Appl Biomater 2007;80:541-546.ArticlePubMed
- 17. Lee YK. Influence of filler on the difference between the transmitted and reflected colors of experimental resin composites. Dent Mater 2008;24:1243-1247.ArticlePubMed
- 18. Campbell PM, Johnston WM, O'Brien WJ. Light scattering and gloss of an experimental quartz-filled composite. J Dent Res 1986;65:892-894.ArticlePubMedPDF
- 19. Kim SJ, Son HH, Cho BH, Lee IB, Um CM. Translucency and masking ability of various opaque-shade composite resins. J Dent 2009;37:102-107.ArticlePubMed
Citations
Citations to this article as recorded by 
- Experimental study of polishing systems on surface roughness and color stability of novel bulk-fill composite resins
Seda Nur Karakaş, Sevde Gül Batmaz, Volkan Çiftçi, Cihan Küden
BMC Oral Health.2025;[Epub] CrossRef - Predictors of procedural errors in class II resin composite restorations using bitewing radiographs
Abdulrahman A. Balhaddad, Nawaf AlGhamdi, Mohammed Alqahtani, Osama A. Alsulaiman, Ali Alshammari, Malik J. Farraj, Ahmed A. Alsulaiman
The Saudi Dental Journal.2024; 36(4): 638. CrossRef - Evaluation of Surface Roughness and Microhardness of Bulk-fill and Nanohybrid Composite after Exposure to Different Beverages at Various Time Intervals – An In vitro Study
Sachin Bengal, Gautam P. Badole, Pratima R. Shenoi, Rajesh Kubde, Shriya Shahu
Annals of African Medicine.2024; 23(3): 466. CrossRef - Influence of Light‐Curing Time and Increment Thickness on the Properties of Bulk Fill Composite Resins With Distinct Application Systems
Carlos Rocha Gomes Torres, Taiana Paola Prado, Daniele Mara da Silva Ávila, Cesar Rogério Pucci, Alessandra Bühler Borges, Heng Bo Jiang
International Journal of Dentistry.2024;[Epub] CrossRef - Preheating effect on microhardness and depth of cure of three bulk-fill composite resins: An in vitro study
Aashna Sunil Sahetia, Divya Rupesh Jain, Padmaja Panditrao Sirsat, Meenal N. Gulve, Swapnil J. Kolhe, Surbhi P. Patel
Endodontology.2024;[Epub] CrossRef - Clinical Longevity of Sonicated and Unsonicated Composite Resin Restorations in Posterior Permanent Teeth: A Systematic Review and Meta-Analysis
Lorrane Salvador de Mello, Fabiola Fontes Galdino, Jayzon Stephan Brooks, Tatiana Kelly da Silva Fidalgo, Kátia Rodrigues Reis
Pesquisa Brasileira em Odontopediatria e Clínica Integrada.2024;[Epub] CrossRef - Translucency of bulk‐fill composite materials: A systematic review
Gaetano Paolone, Sofia Baldani, Niccolò De Masi, Mauro Mandurino, Giacomo Collivasone, Nicola Scotti, Enrico Gherlone, Giuseppe Cantatore
Journal of Esthetic and Restorative Dentistry.2024; 36(7): 995. CrossRef - Assessment of Microhardness of Bulk-Fill Class II Resin Composite Restorations Performed by Preclinical Students: An In Vitro Study
Ali Abdel-Halim Abdel-Azim Hassan, Abdulelah Sameer Sindi, Abeer Mohamed Atout, Mohamed SM Morsy, Khurshid A. Mattoo, Vishnu Teja Obulareddy, Ankita Mathur, Vini Mehta
European Journal of General Dentistry.2024; 13(02): 158. CrossRef - Effect of Indenter Load on Vickers Microhardness and Indentation Depth of One Resin Composite
Richard B. Price, Braden Sullivan
Materials.2024; 17(24): 6156. CrossRef - The Effect of Layer Thickness and Light Intensity on the Degree of Conversion, Microhardness and Cytotoxicity of Bulk Fill Composite Resins
Sevde Gül BATMAZ, Ayşe DÜNDAR, Çağatay BARUTÇUGİL
Clinical and Experimental Health Sciences.2023; 13(4): 795. CrossRef - Comparative Evaluation of the Color Stability and Clinical performance of bulk-filled composites: A Split-mouth Randomized Controlled Trial
Karuna YM, Srikant N, Kundabala M, Anupama Nayak P, Ashwin Rao, Maimoona TM
Research Journal of Pharmacy and Technology.2023; : 5091. CrossRef - Effect of Using Manufacturer-recommended Exposure Times to Photo-activate Bulk-fill and Conventional Resin-based Composites
LM Barcelos, SSL Braga, RAS Pereira, RB Price, CJ Soares
Operative Dentistry.2023; 48(3): 304. CrossRef - Effect of Different Polymerization Times on Color Change, Translucency Parameter, and Surface Hardness of Bulk-Fill Resin Composites
HY Gonder, M Fidan
Nigerian Journal of Clinical Practice.2022; 25(10): 1751. CrossRef - The effect of contemporary finishing and polishing systems on the surface roughness of bulk fill resin composite and nanocomposites
Seda Gömleksiz, Oğuzhan Gömleksiz
Journal of Esthetic and Restorative Dentistry.2022; 34(6): 915. CrossRef - Evaluation of the microleakage in class II cavities restored with composite resin by using different placement techniques and light cure units– An in vitro study
Swathi Miskin, Chandrasekhar Manduru, Nagalakshmi Reddy Sampathi, Upendranatha Reddy Nagireddy, Sujayeendranatha Reddy E, Sushma Chandra
International Dental Journal of Student's Research.2022; 10(2): 53. CrossRef - Comparison of mechanical and optical properties of a newly marketed universal composite resin with contemporary universal composite resins: An in vitro study
Sevil Gurgan, Uzay Koc Vural, Ivana Miletic
Microscopy Research and Technique.2022; 85(3): 1171. CrossRef - Effect of Additional Light Curing on Colour Stability of Composite Resins
Kubra Alan Unsal, Emel Karaman
International Dental Journal.2022; 72(3): 346. CrossRef - Evaluation of Glass-Ionomer versus Bulk-Fill Resin Composite: A Two-Year Randomized Clinical Study
İlhan Uzel, Arzu Aykut-Yetkiner, Nazan Ersin, Fahinur Ertuğrul, Elif Atila, Mutlu Özcan
Materials.2022; 15(20): 7271. CrossRef - Awareness and Utilization of Bulk-Fill Composites among Dental Practitioners in Saudi Arabia
Hani M. Nassar, Ensanya A. Abou Neel
The Open Dentistry Journal.2021; 15(1): 160. CrossRef - Dental Bulk-Fill Resin Composites Polymerization Efficiency: A Systematic Review and Meta-Analysis
Reem Ajaj, Nada Farsi, Lama Alzain, Nour Nuwaylati, Raneem Ghurab, Hani Nassar
Journal of Composites Science.2021; 5(6): 149. CrossRef - Handling and Mechanical Properties of Low-viscosity Bulk-fill Resin Composites
E Hirokane, T Takamizawa, T Tamura, S Shibasaki, A Tsujimoto, WW Barkmeier, MA Latta, M Miyazaki
Operative Dentistry.2021; 46(5): E185. CrossRef - Utilizing Light Cure Units: A Concise Narrative Review
Fatin A. Hasanain, Hani M. Nassar
Polymers.2021; 13(10): 1596. CrossRef - The Effect of Different Dietary and Therapeutic Solutions on the Color Stability of Resin-Matrix Composites Used in Dentistry: An In Vitro Study
Lígia Lopes-Rocha, José Manuel Mendes, Joana Garcez, Ana Góis Sá, Teresa Pinho, Júlio C. M. Souza, Orlanda Torres
Materials.2021; 14(21): 6267. CrossRef - Fracture resistance of endodontically treated premolars restored with bulk-fill composite resins
Fereshteh Shafiei, Paria Dehghanian, Nasibeh Ghaderi, Maryam Doozandeh
Dental Research Journal.2021; 18(1): 60. CrossRef - Mechanical properties of low and regular viscosity bulk fill composites in a 3D dentin cavity model
Rodolfo Xavier Sousa-Lima, Ana Margarida dos Santos Melo, Lílian Karine Cardoso Guimarães, Rodrigo Othávio de Assunção e Souza, Marília Regalado Galvão Rabelo Caldas, Isauremi Vieira de Assunção, Boniek Castillo Dutra Borges
Journal of Adhesion Science and Technology.2021; 35(3): 325. CrossRef - Impact of light-cure protocols on the porosity and shrinkage of commercial bulk fill dental resin composites with different flowability
Daina Dayana Arenas Buelvas, João Felipe Besegato, Bruno Luiz Santana Vicentin, Eduardo Inocente Jussiani, Márcio Grama Hoeppner, Avacir Casanova Andrello, Eduardo Di Mauro
Journal of Polymer Research.2020;[Epub] CrossRef - Effect of time on the post-irradiation curing of six resin-based composites
Christina Kaiser, Richard Bengt Price
Dental Materials.2020; 36(8): 1019. CrossRef The Effects of Irradiance on Translucency and Surface Gloss of Different Bulk-Fill Composite Resins: An in vitro Study
Abrar N Bin Nooh, Hend Al Nahedh, Mohammad AlRefeai, Fahad AlKhudhairy
Clinical, Cosmetic and Investigational Dentistry.2020; Volume 12: 571. CrossRef- Color Stability and Micro-Hardness of Bulk-Fill Composite Materials after Exposure to Common Beverages
Nora Bahbishi, Waad Mzain, Bayan Badeeb, Hani M. Nassar
Materials.2020; 13(3): 787. CrossRef - Polymerization Stress and Gap Formation of Self-adhesive, Bulk-fill and Flowable Composite Resins
EL Nakano, ASC de Souza, LCC Boaro, LH Catalani, RR Braga, F Gonçalves
Operative Dentistry.2020; 45(6): E308. CrossRef - Varying the Polishing Protocol Influences the Color Stability and Surface Roughness of Bulk-Fill Resin-Based Composites
Filipa Freitas, Teresa Pinheiro de Melo, António HS Delgado, Paulo Monteiro, João Rua, Luís Proença, Jorge Caldeira, Ana Mano Azul, José João Mendes
Journal of Functional Biomaterials.2020; 12(1): 1. CrossRef - Characterization and Comparative Analysis of Voids in Class II Composite Resin Restorations by Optical Coherence Tomography
CA Pardo Díaz, CAK Shimokawa, CS Sampaio, AZ Freitas, ML Turbino
Operative Dentistry.2020; 45(1): 71. CrossRef - Clinical performance and chemical-physical properties of bulk fill composites resin —a systematic review and meta-analysis
Leticia Cristina Cidreira Boaro, Diana Pereira Lopes, Andréia Santos Caetano de Souza, Ellea Lie Nakano, Mirko Dennys Ayala Perez, Carmem Silvia Pfeifer, Flávia Gonçalves
Dental Materials.2019; 35(10): e249. CrossRef - Evaluation of the Polymerization Depth of Bulk Fill Resin Composites Polymerized by Different Procedures: An In-Vitro Study
Esra ÖZYURT, Aysegul KURT, Handan YILDIRIM
Clinical and Experimental Health Sciences.2019; 9(4): 304. CrossRef - Internal adaptation of composite restorations with or without an intermediate layer: Effect of polymerization shrinkage parameters of the layer material
Seung-Hoon Han, Alireza Sadr, Yasushi Shimada, Junji Tagami, Sung-Ho Park
Journal of Dentistry.2019; 80: 41. CrossRef - Color Stability of Bulk-Fill Resin Composites after Immersion in Different Media
Sungkyoon Kang, Jihyun Song
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY.2019; 46(4): 353. CrossRef - Degree of Conversion and Polymerization Shrinkage of Low Shrinkage Bulk-Fill Resin Composites
Haidy N. Salem, Sherif M. Hefnawy, Shaymaa M. Nagi
Contemporary Clinical Dentistry.2019; 10(3): 465. CrossRef - Bulk-Fill Composites: Effectiveness of Cure With Poly- and Monowave Curing Lights and Modes
JK Gan, AU Yap, JW Cheong, N Arista, CBK Tan
Operative Dentistry.2018; 43(2): 136. CrossRef - Depth of cure of bulk fill resin composites: A systematic review
Renally Bezerra Wanderley Lima, Cristhian Camilo Madrid Troconis, Marina Barrêto Pereira Moreno, Fabián Murillo‐Gómez, Mario Fernando De Goes
Journal of Esthetic and Restorative Dentistry.2018; 30(6): 492. CrossRef - Influence of Bulk Thickness, Curing Time, and Curing Unit Type on the Microhardness of Different-Viscosity Bulk-Fill Composites
M. Saipullaev, U. Erdemir, E. Yildiz
Mechanics of Composite Materials.2018; 54(5): 675. CrossRef - Color of bulk‐fill composite resin restorative materials
Çağatay Barutcigil, Kubilay Barutcigil, Mehmet Mustafa Özarslan, Ayşe Dündar, Burak Yilmaz
Journal of Esthetic and Restorative Dentistry.2018;[Epub] CrossRef - Incremental and Bulk-fill Techniques With Bulk-fill Resin Composite in Different Cavity Configurations
S-H Han, S-H Park
Operative Dentistry.2018; 43(6): 631. CrossRef - Surface changes of various bulk‐fill resin‐based composites after exposure to different food‐simulating liquid and beverages
Saijai Tanthanuch, Boonlert Kukiattrakoon, Kasidit Eiam‐O‐Pas, Kan Pokawattana, Nicha Pamanee, Wichachon Thongkamkaew, Asok Kochatung
Journal of Esthetic and Restorative Dentistry.2018; 30(2): 126. CrossRef - Impact of 35% Hydrogen Peroxide on Color and Translucency Changes in Enamel and Dentin
Rebeca Pereira de Menezes, Paula Damasceno Silva, Pollyana Caldeira Leal, André Luis Faria-e-Silva
Brazilian Dental Journal.2018; 29(1): 88. CrossRef - A comparative study of bulk-fill composites: degree of conversion, post-gel shrinkage and cytotoxicity
Flávia Gonçalves, Luiza Mello de Paiva Campos, Ezequias Costa Rodrigues-Júnior, Fabrícia Viana Costa, Pamela Adeline Marques, Carlos Eduardo Francci, Roberto Ruggiero Braga, Letícia Cristina Cidreira Boaro
Brazilian Oral Research.2018;[Epub] CrossRef - Comparison of cytotoxicity test models for evaluating resin-based composites
SM Lim, AUJ Yap, CSL Loo, J Ng, CY Goh, CHL Hong, WS Toh
Human & Experimental Toxicology.2017; 36(4): 339. CrossRef - Comparison of Internal Adaptation in Class II Bulk-fill Composite Restorations Using Micro-CT
SH Han, SH Park
Operative Dentistry.2017; 42(2): 203. CrossRef - Color stability of bulk-fill and incremental-fill resin-based composites polished with aluminum-oxide impregnated disks
Uzay Koc-Vural, Ismail Baltacioglu, Pinar Altinci
Restorative Dentistry & Endodontics.2017; 42(2): 118. CrossRef - Evaluation of bulk-fill resin composite on the shear bond strength of metal brackets
Mi-Gyoung Park
Korean Journal of Dental Materials.2017; 44(2): 95. CrossRef - Effect of water storage on flexural strength of silorane and methacrylate-based composite resins
Narges Panahandeh, Hassan Torabzadeh, Hani Naderi, Seyedeh Mahsa Sheikh-Al-Eslamian
Restorative Dentistry & Endodontics.2017; 42(4): 309. CrossRef - Shear bond strength of different dentin substitute restorative materials to dentin of primary teeth
Faika ABDELMEGID, Fouad SALAMA, Nawaf ALBOGAMI, Muhannad ALBABTAIN, Abdulkareem ALQAHTANI
Dental Materials Journal.2016; 35(5): 782. CrossRef - Internal adaptation of resin composites at two configurations: Influence of polymerization shrinkage and stress
Seung-Hoon Han, Alireza Sadr, Junji Tagami, Sung-Ho Park
Dental Materials.2016; 32(9): 1085. CrossRef - Effect of a broad-spectrum LED curing light on the Knoop microhardness of four posterior resin based composites at 2, 4 and 6-mm depths
Maan M. ALShaafi, Thomas Haenel, Braden Sullivan, Daniel Labrie, Mohammed Q. Alqahtani, Richard B. Price
Journal of Dentistry.2016; 45: 14. CrossRef - Influence of increment thickness on light transmission, degree of conversion and micro hardness of bulk fill composites
Sufyan Garoushi, Pekka Vallittu, Akikazu Shinya, Lippo Lassila
Odontology.2016; 104(3): 291. CrossRef - Criteria for clinical translucency evaluation of direct esthetic restorative materials
Yong-Keun Lee
Restorative Dentistry & Endodontics.2016; 41(3): 159. CrossRef - The effect of different drinks on the color stability of different restorative materials after one month
Neslihan Tekçe, Safa Tuncer, Mustafa Demirci, Merve Efe Serim, Canan Baydemir
Restorative Dentistry & Endodontics.2015; 40(4): 255. CrossRef
ePub Link
Cite
XML DownloadEffect of resin thickness on the microhardness and optical properties of bulk-fill resin composites
Figure 1 Comparison of microhardness among different thicknesses.Inverted triangle (▾) indicates no significant difference.VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 2 Translucency parameter (TP) and ΔTP of each group.ΔTP23 means the difference between TP2mm and TP3mm, and ΔTP24 means the difference between TP2mm and TP4mm.VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 3 Correlation between microhardness and TP according to resin thickness.VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Figure 1
Figure 2
Figure 3
Effect of resin thickness on the microhardness and optical properties of bulk-fill resin composites
Resin composites used in this study
| Material / shade | Manufacturer | Resin matrix | Filler | Filler content (wt%) | Recommendation | |
|---|---|---|---|---|---|---|
| Flowable composite | Venus Bulk Fill (VB) / Universal shade | Heraeus Kulzer, Hanau, Germany | UDMA, EBADMA | Ba-Al-F-Si glass, SiO2 | 65 | 4 mm bulk-filling with a capping layer |
| SDR (SR) / Universal shade | Dentsply Caulk, Milford, DE, USA | Modified UDMA, TEGDMA, EBADMA | Ba-Al-F-B-Si glass, St-Al-F-Si glass | 68 | 4 mm bulk-filling with a capping layer | |
| Charisma flow (CF) / A2 shade | Heraeus Kulzer, Hanau, Germany | EBADMA, TEGDMA | Ba-Al-F silicate glass, SiO2 | 62 | 2 mm incremental filling | |
| Non-flowable composite | Tetric N-Ceram Bulk Fill (TB) / IVA shade | Ivoclar vivadent, Schaan, Liechtenstein | Bis-GMA, UDMA | Ba-Al-Si glass, prepolymerized filler (monomer, glass filler, and ytterbium fluoride), pherical mixed oxide | 75 - 77 | 4 mm bulk-filling without capping |
| SonicFill (SO) / A2 shade | Kerr, Orange, CA, USA | Bis-GMA, TEGDMA, EBADMA | SiO2, glass, oxide | 83.5 | 5 mm bulk-filling without capping | |
| Tetric N-Ceram (TN) / A2 shade | Ivoclar vivadent, Schaan, Liechtenstein | Bis-GMA, UDMA | Ba glass, Ytterbium trifluoride, mixed oxide | 80 - 81 | 2 mm incremental filling | |
UDMA, urethane dimethacrylate; EBADMA, ethoxylated bisphenol A dimethacrylate; TEGDMA, triethyleneglycol dimethacrylate; Bis-GMA, bisphenol A diglycidyl ether dimethacrylate.
Microhardness (Hv) for the different thickness
| Group | 0 mm | 2 mm | 3 mm | 4 mm | |
|---|---|---|---|---|---|
| Flowable composite | VB | 25.87 ± 0.17d | 24.52 ± 0.22c | 24.19 ± 0.30c | 24.37 ± 0.39c |
| SR | 33.77 ± 0.51h | 31.68 ± 0.67g | 30.39 ± 0.26f | 29.48 ± 0.72f | |
| CF | 24.26 ± 1.30c | 23.52 ± 0.45bc | 22.84 ± 0.33b | 14.66 ± 0.44a | |
| Non-flowable composite | TB | 51.98 ± 0.71m | 50.58 ± 0.53l | 42.92 ± 0.39k | 40.91 ± 0.76j |
| SO | 77.56 ± 0.31p | 70.65 ± 1.07o | 69.53 ± 1.22o | 65.75 ± 0.86n | |
| TN | 51.96 ± 0.88m | 42.99 ± 0.58k | 38.72 ± 0.96i | 27.23 ± 0.86e | |
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Different superscript letters indicate a statistically significant difference among groups (p < 0.05).
Statistical results: model, p < 0.001; resin composites, p < 0.001; thickness, p < 0.001; interaction effect of resin composites × thickness, p < 0.001.
Generalized linear model for comparison of resin composites and thickness, as well as their interaction
| Variable | Type III sum of squares | df | Mean square | F | p |
|---|---|---|---|---|---|
| Intercept | 31339.181 | 1 | 31339.181 | 55613.467 | 0 |
| Resin composite | 14831.240 | 5 | 2966.248 | 5263.805 | 0 |
| Thickness | 3036.727 | 2 | 1518.364 | 2694.437 | 0 |
| Resin composite*thickness | 71.349 | 10 | 7.135 | 12.661 | 0 |
Adjusted R2 = 0.994.
CIE L*a*b* color coordinate values of resin composites with different thickness
| Group | 2 mm | 3 mm | 4 mm | ||||||
|---|---|---|---|---|---|---|---|---|---|
| L* | a* | b* | L* | a* | b* | L* | a* | b* | |
| VB | 43.57 ± 1.65 | -5.51 ± 0.24 | -4.45 ± 0.88 | 45.23 ± 1.62 | -5.66 ± 0.37 | -1.70 ± 0.85 | 44.16 ± 0.85 | -5.85 ± 0.06 | 1.39 ± 0.35 |
| SR | 63.34 ± 1.19 | -4.42 ± 0.23 | -1.95 ± 0.30 | 63.23 ± 0.70 | -4.51 ± 0.05 | -1.49 ± 0.35 | 64.55 ± 0.29 | -5.19 ± 0.02 | -1.58 ± 0.30 |
| CF | 59.71 ± 0.80 | 0.01 ± 0.08 | 9.10 ± 0.34 | 59.35 ± 0.51 | 0.36 ± 0.20 | 9.40 ± 0.58 | 58.31 ± 0.48 | 0.43 ± 0.17 | 9.19 ± 0.54 |
| TB | 60.48 ± 0.36 | -3.16 ± 0.03 | 8.67 ± 0.48 | 61.31 ± 0.65 | -2.96 ± 0.05 | 9.18 ± 0.50 | 61.26 ± 0.55 | -2.90 ± 0.12 | 9.23 ± 0.44 |
| SO | 63.04 ± 0.71 | 1.23 ± 0.15 | 4.24 ± 0.25 | 63.38 ± 0.49 | 1.56 ± 0.32 | 4.82 ± 0.71 | 63.48 ± 0.34 | 1.78 ± 0.07 | 4.91 ± 0.22 |
| TN | 63.26 ± 1.06 | -0.01 ± 0.13 | 11.65 ± 0.68 | 63.99 ± 1.08 | 0.16 ± 0.08 | 12.36 ± 0.86 | 61.94 ± 0.46 | 1.11 ± 0.16 | 14.30 ± 0.23 |
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Color difference (ΔE) values for the different thickness
| Group | ΔE23 | ΔE24 | p value* | ||
|---|---|---|---|---|---|
| Flowable composite | Bulk-fill | VB | 3.33 ± 1.26 | 6.03 ± 0.83 | p < 0.05 |
| SR | 1.62 ± 0.20 | 2.08 ± 0.58 | p < 0.05 | ||
| Regular | CF | 1.00 ± 0.40 | 1.68 ± 0.47 | p < 0.05 | |
| Non-flowable composite | Bulk-fill | TB | 1.54 ± 0.82 | 1.21 ± 0.45 | p > 0.05 |
| SO | 1.11 ± 0.55 | 1.10 ± 0.37 | p > 0.05 | ||
| Regular | TN | 2.07 ± 0.66 | 3.39 ± 0.81 | p < 0.05 |
*Student t-test.
ΔE23 means ΔE between 2 mm and 3 mm specimens, and ΔE24 means ΔE between 2 mm and 4 mm specimens.
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Table 1 Resin composites used in this study
UDMA, urethane dimethacrylate; EBADMA, ethoxylated bisphenol A dimethacrylate; TEGDMA, triethyleneglycol dimethacrylate; Bis-GMA, bisphenol A diglycidyl ether dimethacrylate.
Table 2 Microhardness (Hv) for the different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Different superscript letters indicate a statistically significant difference among groups (
Statistical results: model,
Table 3 Generalized linear model for comparison of resin composites and thickness, as well as their interaction
Adjusted R2 = 0.994.
Table 4 CIE L*a*b* color coordinate values of resin composites with different thickness
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
Table 5 Color difference (ΔE) values for the different thickness
*Student
Δ
VB, Venus Bulk Fill; SR, SDR; CF, Charisma flow; TB, Tetric N-Ceram Bulk Fill; SO, SonicFill; TN, Tetric N-Ceram.
