- Email: [email protected]
Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites
Materials Today: Proceedings xxx (xxxx) xxx
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites Bhanu Pratap, Ravi Kant Gupta ⇑, Leo Denis, Dhara Goswami Department of Mechanical Engineering, Manipal University Jaipur, Rajasthan, India
a r t i c l e
i n f o
Article history: Received 23 September 2019 Received in revised form 4 October 2019 Accepted 8 November 2019 Available online xxxx Keywords: Resin Zinc oxide Polymerization shrinkage Micro-hardness Dental composite
a b s t r a c t In this article, BisGMA and TEGDMA were used as resin material to fabricate dental composite. Camphorquinone was used as photoinitiator and DMAEA was used as coinitiator. Different %wt of micro sized zinc oxide (0%, 3%, 6% and 9%) was used as filler to study the effect of different compositions of zinc oxide filled dental composite. Resin matrix with different compositions were prepared to fabricate dental composite samples. Polymerization shrinkage and Vickers micro-hardness were measured. This study reveals experimentally that introduction of zinc oxide in dental resin significantly reduces polymerization shrinkage and improves micro-hardness of the restorative dental composite. Minimum polymerization shrinkage of 8.02% and maximum micro-hardness of 80 Hv were achieved at 9 %wt of zinc oxide as filler in dental composite. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Mechanical and Energy Technologies.
1. Introduction The dental composites which are resin based, have been used for the purpose of restorations of the tooth as they have lot of benefits over the other conventional dental restorative materials such as good aesthetics, low cost along with better physical and wear properties [1]. However the main problem is the undesirable shrinkage due to low rate of polymerization conversion [2]. Irrespective of significant development in the resin composites, they have two short comings: high polymerization shrinkage and low mechanical strength as compared to amalgam [3]. For resin based dental restorative materials, BisGMA is one the most commonly used monomer due to its fine aesthetics. It is highly viscous in nature [4]. However, high viscosity of BisGMA doesn’t allow uniform mixing of filler particles in it directly. So, Tri-ethylene-glycol-dime thacrylate (TEGDMA) is generally used as diluent to reduce the viscosity of BisGMA [5]. For the polymerization process of BisGMA and TEGDMA resins, photoinitiators are used. Camphorquinone (CQ) is the most commonly used photo initiator [6]. It is yellow in color but this colour bleaches during the curing process at later stage [7].
⇑ Corresponding author. E-mail address: [email protected] ( Ravi Kant Gupta).
To improve polymerization process of the resin matrix, accelerators/co-initiators are utilized. In dental restorations, durable and strong bonding is required between resin composite and dental restorative materials. Coupling agent can enhance the weak bonding at the interface. Hennce, silane treatment of filler particles is carried out to improve adhesion characteristics among resin and filler materials [8]. One of the commonly used silanes used in fabrication of dental composites is 3-methacryloxypropyltrimethoxy silane [9]. It is pre-hydrolyzed in a mixture solvent generally consisting of ethanol and water and later it is acidified with the help of acetic acid. Many researchers have used various silane treated filler particles of varying particle size to study the physical, mechanical properties and wear properties of resin based dental composites. Recently, Pratap et al. [10] investigated optimum combination of various process parameters during fabrication process of dental composites to achieve better polymerization shrinkage and micro-hardness using nano-alumina as filler material. Sonal et al. [11] studied effect of adding nano-silica partciles to study mechanical and wear behavior of resin based composite. Pratap et al. [12] also studied effect of micro-silica as filler material on physical properties of resin based dental restorative composites. AmiroucheKorichi [13] studied shrinkage strain-rate by studying the effect of various fillers with varying BisGMA/TEGDMA content. From the available literature, it was revealed that polymerization shrinkage and micro-hardness are the important characteristics of the dental
https://doi.org/10.1016/j.matpr.2019.11.090 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Mechanical and Energy Technologies.
Please cite this article as: B. Pratap, Ravi Kant Gupta, L. Denis et al., Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.11.090
2
B. Pratap et al. / Materials Today: Proceedings xxx (xxxx) xxx
composite. The aim of this study was to investigate the effect of different %wt. micro-sized zinc oxide on the polymerization shrinkage and micro-hardness of dental restorative composite. 2. Material and methods The monomer resins Bis-GMA (Tokyo Chemical Industry, Japan) was mixed with diluent monomer which is TEGDMA (Tokyo Chemical Industry, Japan) in the ratio of 70:30 by weightage percentage. Now this mixture is stirred for about two hours so that all the constituents are homogenously mixed. Micro sized zinc oxide with particle size of 5 mm was added as the filler particle by weight percentage (3%, 6% and 9%) to the resin mixture. Camphorquinone (Spectrochem Pvt. Ltd., Mumbai) was used as an initiator and DMAEA [0.0125% wt. of matrix] (TCI, Japan) was used a coinitiator. After the addition of all materials the mixture is mixed for an hour. At this state the exposure to light should be avoided so that there is no premature polymerization. LED Light Curing Unit (1200 mW/cm2, 450 to 490 nm) was employed to polymerize the resin matrix. The samples having different %wt. of filler particles were cured by light for 30 s (Table 1). 3. Methodology 3.1. Polymerization shrinkage A polymer occupies less volume than the monomer, this effect is known as polymerization shrinkage. During the polymerization process, weak van der waals forces are converted into stronger covalent bonds and this results in reduction of distance between the molecules of monomers. Polymerization shrinkage is calculated as per ISO 4049 which is based on Archimedes principle. Weights of cured test samples and uncured test samples were measured in air and water. Eqs. (1) and (2) were used to measure specific gravity and density of cured and uncured test samples, respectively.
Specific Gravity ¼
Duncured M1 ¼ 100 Dw M1 M2
Density of Uncured Sample ¼ Duncured ¼
ð1Þ
M1 Dw M1 M2
ð2Þ
Here, M1 is the mass of uncured sample in air and water while M2 is the mass of uncured sample in water. Duncured is the density of uncured sample in air and Dw is density of water. After measuring, density of uncured samples, the samples were cured for 30 s and density of cured samples (Dcured) were measured for the samples. Using Eq. (3), Polymerization Shrinkage was measured for dental composite samples.
PolymerizationShrinkage ¼
Dcured Duncured 100 Dcured
ð3Þ
3.2. Vickers hardness testing
used to determine the hardness of a material [9]. So, it can be said that resistance produced by a material to external penetration/ indentation is known as hardness. To measure the Vickers microhardness, a 300 g load was applied on six different places of the dental composite samples. The mean values of micro-hardness measured as per ASTM E384-11e1. The Formula used to calculate Vickers micro-hardness is shown in following Eq. (4).
HV ¼ 1:854
F
ð4Þ
2
d
where, F is Load in kgf, d is Arithmetic mean of the two diagonals and HV is Vickers Hardness Number. 4. Experimental results and discussion 4.1. Polymerization shrinkage Using the methodology as stated in above section, polymerization shrinkage of test samples was calculated. For a particular composition, three samples were taken into consideration and the mean values of three samples were calculated. Results of polymerization shrinkage test of the specimens are presented in the following Table 2. From the results of polymerization shrinkage, it can be clearly stated that polymerization shrinkage reduces significantly with increase in filler loading. These results are in good agreement with previous studies [9,13,14]. This trend may be due to the fact that with more filler particles, incident light energy may scatter. So, such results concludes that more filler loading decreases polymerization shrinkage significantly. 4.2. Vickers hardness test For calculation of Vickers hardness, three samples of particular composition were taken into consideration and the mean values of three samples were calculated. For each sample, six indentations (d) were measured and used to calculate micro-hardness using Eq. (4). The results of Vickers hardness test of the specimens are presented in the following Table 3. From the results of Vickers micro-hardness test, it can be clearly stated that with increase in filler loading, micro-hardness increases significantly. These results are also in good agreement of previous studies [10,15,16,17]. Such tend may be associated with the fact that zinc oxide is a ceramic filler which is quite stiffer. Resin materials are quite elastic so with addition of more zinc oxide, microhardness increases.
Table 2 Results of shrinkage percentage in composites. Sr. No.
Sample
Shrinkage Percentage
1 2 3 4
RBDC-0 RBDC-3 RBDC-6 RBDC-9
15.2% 11.67% 9.91% 8.02%
Hardness is an important characteristic of a material which gives the resistance to indentation. Depth of the indentation is Table 3 Results of Vickers micro-hardness test.
Table 1 Composition of zinc oxide filled dental composite. Sample Designation RBDC-0 RBDC-3 RBDC-6 RBDC-9
Composition
S. No.
Materials
Mean Hardness Value (HV)
Resin Matrix Resin + Filler Resin + Filler Resin + Filler
1 2 3 4
RBDC-0 RBDC-3 RBDC-6 RBDC-9
44 66.34 79.67 80
only (3%) (6%) (9%)
Please cite this article as: B. Pratap, Ravi Kant Gupta, L. Denis et al., Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.11.090
B. Pratap et al. / Materials Today: Proceedings xxx (xxxx) xxx
5. Conclusion The experimental results obtained from this study shows that shrinkage due to polymerization is reduced as concentration of filler particles is increased, hence adding filler particles upto 9% reduces the polymerization upto acceptable limits. Also, values of micro-hardness value increases significantly when filler material is added. So, it can be concluded that introduction of zinc oxide in dental resin significantly reduces polymerization shrinkage and improves micro-hardness of the restorative dental composite. In further studies, effect of various process parameters of fabrication of dental restorative materials using nano-zinc oxide can be carried out using DOE [18]. References [1] R. Yadav, M. Kumar, Dental restorative composite materials: a review, J. Oral Biosci. 61 (2) (2019) 78–83. [2] S. Pamela, J.S. Stein, J.E. Haubenreicb, P.B. Osborne, Composite resin in medicine and dentistry, J. Long-Term Effects Med. Implants 15 (2005) 641– 654. [3] D.A. Terry, Direct applications of a nanocomposite resin system. Part 2. Procedures for anterior restorations, Pract. Proced. Aesthet. Dent 16 (2004) 677–684. [4] Pratap B, Gupta RK, Ghosh SS & Bhardwaj B, Process parameter optimization for minimum polymerization shrinkage of resin based dental material. In AIP Conference Proceedings (Vol. 2148, No. 1, p. 030020). (2019, September) AIP Publishing. [5] K.L. Van Landuyt, J. Snauwaert, J. De Munck, M. Peumans, Y. Yoshida, A. Poitevin, et al., Systematic review of the chemical composition of contemporary dental adhesives, Biomaterials 28 (2007) 3757–3785. [6] I.D. Sideridou, D.S. Achilias, Elution study of unreacted Bis-GMA, TEGDMA, UDMA, and Bis-EMA from light-cured dental resins and resin composites using HPLC, J. Biomed. Mater. Res. Part B: Appl. Biomater. 74B (2005) 617–626.
3
[7] B. Pratap, R.K. Gupta, B. Bhardwaj, M. Nag, Resin based restorative dental materials: characteristics and future perspectives, Japanese Dental Sci. Rev. 55 (1) (2019). [8] A. Stein, B.J. Melde, R.C. Schroden, Hybrid inorganic–organic mesoporous silicates—nanoscopic reactors coming of age, Adv. Mater. 12 (19) (2000) 1403– 1419. [9] S.R. Kumar, I.K. Bhat, A. Patnaik, Novel dental composite material reinforced with silane functionalized microsized gypsum filler particles, Polym. Compos. 38 (2) (2017) 404–415. [10] B. Pratap, R.K. Gupta, B. Bhardwaj, M. Nag, Modeling based experimental investigation on polymerization shrinkage and micro-hardness of nano alumina filled resin based dental material, J. Mech. Behav. Biomed. Mater. 99 (2019) 86–92, https://doi.org/10.1016/j.jmbbm.2019.06.026. [11] M.G. Sonal, Shiv Ranjan Kumar, Amar Patnaik, Anoj Meena, Effect of Adding Nanosilica Particulate Filler on the Wear Behavior of Dental Composite, Polym. Compos. (2017). [12] B. Pratap, R.K. Gupta, Evaluation of physical properties of silica filled resin based dental composites, Int. J. Eng. Adv. Technol. 8 (6) (2019) 5047–5049. [13] A. Amirouche-Korichi, M. Mouzali, D.C. Watts, Shrinkage strain – rates study of dental composites based on (BisGMA/TEGDMA) monomers, Arab. J. Chem. 10 (Suppl. 1) (2017) S190–S195. [14] F. Goncalves, Y. Kawano, R.R. Braga, Contraction stress related to composite inorganic content, Dent Mater 26 (2010) 704–709. [15] E.G. Mota, A. Weiss, A.M. Spohr, H.M.S. Oshima, Carvalho LMNd. Relationship between filler content and selected mechanical properties of six microhybrid composites, Revista Odonto Ciência 26 (2010) 151–155. [16] S.O. Alsharif, H.B. Akil, N.A. El-Aziz, Z.A. Ahmad. Effect of alumina particles loading on the mechanical properties of light-cured dental resin composites. Materials & Design (1980-2015). 2014 Feb 1;54:430-5. [17] A. Meena, H.S. Mali, A. Patnaik, S.R. Kumar, Effect of adding nanoalumina and marble dust powder on the physical, mechanical, and thermo-mechanical characterization of dental composite, Polym. Compos. 39 (2018) E321–E331. [18] B. Pratap, R.K. Gupta, B. Bhardwaj, Study of Sliding Wear Behavior of Alumina Oxide Filled Fiber Composite Using Design of Experiment, in: Advances in Industrial and Production Engineering, Springer, Singapore, 2019, pp. 735– 742.
Please cite this article as: B. Pratap, Ravi Kant Gupta, L. Denis et al., Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.11.090
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites Bhanu Pratap, Ravi Kant Gupta ⇑, Leo Denis, Dhara Goswami Department of Mechanical Engineering, Manipal University Jaipur, Rajasthan, India
a r t i c l e
i n f o
Article history: Received 23 September 2019 Received in revised form 4 October 2019 Accepted 8 November 2019 Available online xxxx Keywords: Resin Zinc oxide Polymerization shrinkage Micro-hardness Dental composite
a b s t r a c t In this article, BisGMA and TEGDMA were used as resin material to fabricate dental composite. Camphorquinone was used as photoinitiator and DMAEA was used as coinitiator. Different %wt of micro sized zinc oxide (0%, 3%, 6% and 9%) was used as filler to study the effect of different compositions of zinc oxide filled dental composite. Resin matrix with different compositions were prepared to fabricate dental composite samples. Polymerization shrinkage and Vickers micro-hardness were measured. This study reveals experimentally that introduction of zinc oxide in dental resin significantly reduces polymerization shrinkage and improves micro-hardness of the restorative dental composite. Minimum polymerization shrinkage of 8.02% and maximum micro-hardness of 80 Hv were achieved at 9 %wt of zinc oxide as filler in dental composite. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Mechanical and Energy Technologies.
1. Introduction The dental composites which are resin based, have been used for the purpose of restorations of the tooth as they have lot of benefits over the other conventional dental restorative materials such as good aesthetics, low cost along with better physical and wear properties [1]. However the main problem is the undesirable shrinkage due to low rate of polymerization conversion [2]. Irrespective of significant development in the resin composites, they have two short comings: high polymerization shrinkage and low mechanical strength as compared to amalgam [3]. For resin based dental restorative materials, BisGMA is one the most commonly used monomer due to its fine aesthetics. It is highly viscous in nature [4]. However, high viscosity of BisGMA doesn’t allow uniform mixing of filler particles in it directly. So, Tri-ethylene-glycol-dime thacrylate (TEGDMA) is generally used as diluent to reduce the viscosity of BisGMA [5]. For the polymerization process of BisGMA and TEGDMA resins, photoinitiators are used. Camphorquinone (CQ) is the most commonly used photo initiator [6]. It is yellow in color but this colour bleaches during the curing process at later stage [7].
⇑ Corresponding author. E-mail address: [email protected] ( Ravi Kant Gupta).
To improve polymerization process of the resin matrix, accelerators/co-initiators are utilized. In dental restorations, durable and strong bonding is required between resin composite and dental restorative materials. Coupling agent can enhance the weak bonding at the interface. Hennce, silane treatment of filler particles is carried out to improve adhesion characteristics among resin and filler materials [8]. One of the commonly used silanes used in fabrication of dental composites is 3-methacryloxypropyltrimethoxy silane [9]. It is pre-hydrolyzed in a mixture solvent generally consisting of ethanol and water and later it is acidified with the help of acetic acid. Many researchers have used various silane treated filler particles of varying particle size to study the physical, mechanical properties and wear properties of resin based dental composites. Recently, Pratap et al. [10] investigated optimum combination of various process parameters during fabrication process of dental composites to achieve better polymerization shrinkage and micro-hardness using nano-alumina as filler material. Sonal et al. [11] studied effect of adding nano-silica partciles to study mechanical and wear behavior of resin based composite. Pratap et al. [12] also studied effect of micro-silica as filler material on physical properties of resin based dental restorative composites. AmiroucheKorichi [13] studied shrinkage strain-rate by studying the effect of various fillers with varying BisGMA/TEGDMA content. From the available literature, it was revealed that polymerization shrinkage and micro-hardness are the important characteristics of the dental
https://doi.org/10.1016/j.matpr.2019.11.090 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Mechanical and Energy Technologies.
Please cite this article as: B. Pratap, Ravi Kant Gupta, L. Denis et al., Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.11.090
2
B. Pratap et al. / Materials Today: Proceedings xxx (xxxx) xxx
composite. The aim of this study was to investigate the effect of different %wt. micro-sized zinc oxide on the polymerization shrinkage and micro-hardness of dental restorative composite. 2. Material and methods The monomer resins Bis-GMA (Tokyo Chemical Industry, Japan) was mixed with diluent monomer which is TEGDMA (Tokyo Chemical Industry, Japan) in the ratio of 70:30 by weightage percentage. Now this mixture is stirred for about two hours so that all the constituents are homogenously mixed. Micro sized zinc oxide with particle size of 5 mm was added as the filler particle by weight percentage (3%, 6% and 9%) to the resin mixture. Camphorquinone (Spectrochem Pvt. Ltd., Mumbai) was used as an initiator and DMAEA [0.0125% wt. of matrix] (TCI, Japan) was used a coinitiator. After the addition of all materials the mixture is mixed for an hour. At this state the exposure to light should be avoided so that there is no premature polymerization. LED Light Curing Unit (1200 mW/cm2, 450 to 490 nm) was employed to polymerize the resin matrix. The samples having different %wt. of filler particles were cured by light for 30 s (Table 1). 3. Methodology 3.1. Polymerization shrinkage A polymer occupies less volume than the monomer, this effect is known as polymerization shrinkage. During the polymerization process, weak van der waals forces are converted into stronger covalent bonds and this results in reduction of distance between the molecules of monomers. Polymerization shrinkage is calculated as per ISO 4049 which is based on Archimedes principle. Weights of cured test samples and uncured test samples were measured in air and water. Eqs. (1) and (2) were used to measure specific gravity and density of cured and uncured test samples, respectively.
Specific Gravity ¼
Duncured M1 ¼ 100 Dw M1 M2
Density of Uncured Sample ¼ Duncured ¼
ð1Þ
M1 Dw M1 M2
ð2Þ
Here, M1 is the mass of uncured sample in air and water while M2 is the mass of uncured sample in water. Duncured is the density of uncured sample in air and Dw is density of water. After measuring, density of uncured samples, the samples were cured for 30 s and density of cured samples (Dcured) were measured for the samples. Using Eq. (3), Polymerization Shrinkage was measured for dental composite samples.
PolymerizationShrinkage ¼
Dcured Duncured 100 Dcured
ð3Þ
3.2. Vickers hardness testing
used to determine the hardness of a material [9]. So, it can be said that resistance produced by a material to external penetration/ indentation is known as hardness. To measure the Vickers microhardness, a 300 g load was applied on six different places of the dental composite samples. The mean values of micro-hardness measured as per ASTM E384-11e1. The Formula used to calculate Vickers micro-hardness is shown in following Eq. (4).
HV ¼ 1:854
F
ð4Þ
2
d
where, F is Load in kgf, d is Arithmetic mean of the two diagonals and HV is Vickers Hardness Number. 4. Experimental results and discussion 4.1. Polymerization shrinkage Using the methodology as stated in above section, polymerization shrinkage of test samples was calculated. For a particular composition, three samples were taken into consideration and the mean values of three samples were calculated. Results of polymerization shrinkage test of the specimens are presented in the following Table 2. From the results of polymerization shrinkage, it can be clearly stated that polymerization shrinkage reduces significantly with increase in filler loading. These results are in good agreement with previous studies [9,13,14]. This trend may be due to the fact that with more filler particles, incident light energy may scatter. So, such results concludes that more filler loading decreases polymerization shrinkage significantly. 4.2. Vickers hardness test For calculation of Vickers hardness, three samples of particular composition were taken into consideration and the mean values of three samples were calculated. For each sample, six indentations (d) were measured and used to calculate micro-hardness using Eq. (4). The results of Vickers hardness test of the specimens are presented in the following Table 3. From the results of Vickers micro-hardness test, it can be clearly stated that with increase in filler loading, micro-hardness increases significantly. These results are also in good agreement of previous studies [10,15,16,17]. Such tend may be associated with the fact that zinc oxide is a ceramic filler which is quite stiffer. Resin materials are quite elastic so with addition of more zinc oxide, microhardness increases.
Table 2 Results of shrinkage percentage in composites. Sr. No.
Sample
Shrinkage Percentage
1 2 3 4
RBDC-0 RBDC-3 RBDC-6 RBDC-9
15.2% 11.67% 9.91% 8.02%
Hardness is an important characteristic of a material which gives the resistance to indentation. Depth of the indentation is Table 3 Results of Vickers micro-hardness test.
Table 1 Composition of zinc oxide filled dental composite. Sample Designation RBDC-0 RBDC-3 RBDC-6 RBDC-9
Composition
S. No.
Materials
Mean Hardness Value (HV)
Resin Matrix Resin + Filler Resin + Filler Resin + Filler
1 2 3 4
RBDC-0 RBDC-3 RBDC-6 RBDC-9
44 66.34 79.67 80
only (3%) (6%) (9%)
Please cite this article as: B. Pratap, Ravi Kant Gupta, L. Denis et al., Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.11.090
B. Pratap et al. / Materials Today: Proceedings xxx (xxxx) xxx
5. Conclusion The experimental results obtained from this study shows that shrinkage due to polymerization is reduced as concentration of filler particles is increased, hence adding filler particles upto 9% reduces the polymerization upto acceptable limits. Also, values of micro-hardness value increases significantly when filler material is added. So, it can be concluded that introduction of zinc oxide in dental resin significantly reduces polymerization shrinkage and improves micro-hardness of the restorative dental composite. In further studies, effect of various process parameters of fabrication of dental restorative materials using nano-zinc oxide can be carried out using DOE [18]. References [1] R. Yadav, M. Kumar, Dental restorative composite materials: a review, J. Oral Biosci. 61 (2) (2019) 78–83. [2] S. Pamela, J.S. Stein, J.E. Haubenreicb, P.B. Osborne, Composite resin in medicine and dentistry, J. Long-Term Effects Med. Implants 15 (2005) 641– 654. [3] D.A. Terry, Direct applications of a nanocomposite resin system. Part 2. Procedures for anterior restorations, Pract. Proced. Aesthet. Dent 16 (2004) 677–684. [4] Pratap B, Gupta RK, Ghosh SS & Bhardwaj B, Process parameter optimization for minimum polymerization shrinkage of resin based dental material. In AIP Conference Proceedings (Vol. 2148, No. 1, p. 030020). (2019, September) AIP Publishing. [5] K.L. Van Landuyt, J. Snauwaert, J. De Munck, M. Peumans, Y. Yoshida, A. Poitevin, et al., Systematic review of the chemical composition of contemporary dental adhesives, Biomaterials 28 (2007) 3757–3785. [6] I.D. Sideridou, D.S. Achilias, Elution study of unreacted Bis-GMA, TEGDMA, UDMA, and Bis-EMA from light-cured dental resins and resin composites using HPLC, J. Biomed. Mater. Res. Part B: Appl. Biomater. 74B (2005) 617–626.
3
[7] B. Pratap, R.K. Gupta, B. Bhardwaj, M. Nag, Resin based restorative dental materials: characteristics and future perspectives, Japanese Dental Sci. Rev. 55 (1) (2019). [8] A. Stein, B.J. Melde, R.C. Schroden, Hybrid inorganic–organic mesoporous silicates—nanoscopic reactors coming of age, Adv. Mater. 12 (19) (2000) 1403– 1419. [9] S.R. Kumar, I.K. Bhat, A. Patnaik, Novel dental composite material reinforced with silane functionalized microsized gypsum filler particles, Polym. Compos. 38 (2) (2017) 404–415. [10] B. Pratap, R.K. Gupta, B. Bhardwaj, M. Nag, Modeling based experimental investigation on polymerization shrinkage and micro-hardness of nano alumina filled resin based dental material, J. Mech. Behav. Biomed. Mater. 99 (2019) 86–92, https://doi.org/10.1016/j.jmbbm.2019.06.026. [11] M.G. Sonal, Shiv Ranjan Kumar, Amar Patnaik, Anoj Meena, Effect of Adding Nanosilica Particulate Filler on the Wear Behavior of Dental Composite, Polym. Compos. (2017). [12] B. Pratap, R.K. Gupta, Evaluation of physical properties of silica filled resin based dental composites, Int. J. Eng. Adv. Technol. 8 (6) (2019) 5047–5049. [13] A. Amirouche-Korichi, M. Mouzali, D.C. Watts, Shrinkage strain – rates study of dental composites based on (BisGMA/TEGDMA) monomers, Arab. J. Chem. 10 (Suppl. 1) (2017) S190–S195. [14] F. Goncalves, Y. Kawano, R.R. Braga, Contraction stress related to composite inorganic content, Dent Mater 26 (2010) 704–709. [15] E.G. Mota, A. Weiss, A.M. Spohr, H.M.S. Oshima, Carvalho LMNd. Relationship between filler content and selected mechanical properties of six microhybrid composites, Revista Odonto Ciência 26 (2010) 151–155. [16] S.O. Alsharif, H.B. Akil, N.A. El-Aziz, Z.A. Ahmad. Effect of alumina particles loading on the mechanical properties of light-cured dental resin composites. Materials & Design (1980-2015). 2014 Feb 1;54:430-5. [17] A. Meena, H.S. Mali, A. Patnaik, S.R. Kumar, Effect of adding nanoalumina and marble dust powder on the physical, mechanical, and thermo-mechanical characterization of dental composite, Polym. Compos. 39 (2018) E321–E331. [18] B. Pratap, R.K. Gupta, B. Bhardwaj, Study of Sliding Wear Behavior of Alumina Oxide Filled Fiber Composite Using Design of Experiment, in: Advances in Industrial and Production Engineering, Springer, Singapore, 2019, pp. 735– 742.
Please cite this article as: B. Pratap, Ravi Kant Gupta, L. Denis et al., Evaluation of polymerization shrinkage and Vickers hardness for restorative dental composites, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.11.090