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Effect of light intensity on the polymerization rate of composite resin using real-time measurement of volumetric change


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Effect of light intensity on the polymerization rate of composite resin using real-time measurement of volumetric change

Article information

Restor Dent Endod. 2002;27(2):135-141
Publication date (electronic) : 2002 March 31
doi : https://doi.org/10.5395/JKACD.2002.27.2.135
Sung-Ho La, In-Bog Lee, Chang-Keun Kim*, Byeong-Hoon Choorcid_icon, Kwang-Won Lee**, Ho-Hyun Son
Department of Conservative Dentistry, College of Dentistry, Seoul National University, Korea.
*Department of Chemical Engineering, Chung-Ang University, Korea.
**Department of Conservative Dentistry, College of Dentistry, Chonbuk National University, Korea.

Abstract

Objectives

The aim of this study is to evaluate the effect of light intensity variation on the polymerization rate of composite resin using IB system (the experimental equipment designed by Dr. IB Lee) by which real-time volumetric change of composite can be measured.

Methods

Three commercial composite resins [Z100(Z1), AeliteFil(AF), SureFil(SF)] were photopolymerized with Variable Intensity Polymerizer unit (Bisco, U.S.A.) under the variable light intensity (75/150/225/300/375/450mW2) during 20 sec. Polymerization shrinkage of samples was detected continuously by IB system during 110 sec and the rate of polymerization shrinkage was obtained by its shrinkage data. Peak time(P.T.) showing the maximum rate of polymerization shrinkage was used to compare the polymerization rate.

Results

Peak time decreased with increasing light intensity(p<0.05). Maximum rate of polymerization shrinkage increased with increasing light intensity(p<0.05). Statistical analysis revealed a significant positive correlation between peak time and inverse square root of the light intensity (AF:R=0.965, Z1:R=0.974, SF:R=0.927). Statistical analysis revealed a significant negative correlation between the maximum rate of polymerization shrinkage and peak time(AF:R=-0.933, Z1:R=-0.892, SF:R=-0.883), and a significant positive correlation between the maximum rate of polymerization shrinkage and square root of the light intensity (AF:R=0.988, Z1:R=0.974, SF:R=0.946).

Discussion and Conclusions

The polymerization rate of composite resins used in this study was proportional to the square root of light intensity. Maximum rate of polymerization shrinkage as well as peak time can be used to compare the polymerization rate. Real-time volume method using IB system can be a simple, alternative method to obtain the polymerization rate of composite resins.

Keywords: Composite Resin; Volumetric Shrinkage; Rate of Polymerization; Light Intensity; IB system

References

1. Feilzer AJ, de Gee AJ, Davidson CL. Curing contraction of composites and glass-ionomer cements. J Prosthet Dent 1988. 59297–300.
2. Tobolsky AV, Leonard F, Roeser GP. Use of polymerizable ring compounds in constant volume polymerization. J Polym Sci 1948. 3604–606.
3. Retief DH. Do adhesives prevent microleakage? Int Dent J 1994. 44(1)19–26.
4. Davidson CL, de Gee AJ. Relaxation of polymerization contraction stresses by flow in dental composites. J Dent Res 1984. 63(2)146–148.
5. Feilzer AJ, Dooren LH, de Gee AJ, Davidson CL. Influence of light intensity on polymerization shrinkage and integrity of restoration-cavity interface. Eur J Oral Sci 1995. 103322–326.
6. Feilzer AJ, de Gee AJ, Davidson CL. Quantitative determination of stress reduction by flow in composite restorations. Dent Mater 1990. 6167–171.
7. Mehl A, Hickel R, Kunzelmann KH. Physical properties and gap formation of light-cured composites with and without 'softstart-polymerization'. J Dent 1997. 25(3-4)321–330.
8. Kanca J, Suh BI. Pulse activation:reducing resin-based composite contraction stresses at the enamel cavosurface margins. Am J Dent 1999. 12(3)107–112.
9. Suh BI, Cripe CA. Light intensity and exposure time effect on light-cured composites 1998. IADR; 1–6. Abst.#73.
10. Antonucci JM, Toth EE. Extent of polymerization of dental resins by differential scanning calorimetry. J Dent Res 1983. 62(2)121–125.
11. Ruyter IE, Gyorosi PP. An infrared spectroscopic study of sealants. Scand J Dent Res 1976. 84(6)396–400.
12. Venhoven BA, de Gee AJ, Davidson CL. Light initiation of dental resins : dynamics of the polymerization. Biomaterials 1996. 172313–2318.
13. Odian G. Principles of polymerization 1991. 3rd edth ed. John Wiley & Sons, Inc; 198–243. 286–290.
14. Venhoven BAM, de Gee AJ, Davidson CL. polymerization contraction and conversion of light-curing BisGMA-based methacrylate resins. Biomaterials 1993. 14(11)871–875.
15. Loshaek S, Fox TG. Cross-linked polymers. I. Factors influencing the efficiency of cross-linking in copolymers of methyl methacrylates and glycol dimethacrylates. J Am Chem Soc 1953. 753544–3550.
16. Lee IB. A new method - Real time measurement of the initial dynamic volumetric shrinkage of composite resins during polymerization. J Korean Acad Conserv Dent 2001. 26(2)134–140.
17. Rueggeberg F, Tamareselvy K. Resin cure determination by polymerization shrinkage. Dent Mater 1995. 11(4)265–268.
18. Lee IB, Jung KH, Um CM. Thermal analysis of the dual cured resin cements according to curing condition. J Korean Acad Conserv Dent 1999. 24(2)265–285.

Article information Continued

Copyright © 2002 Korean Academy of Conservative Dentistry
(open-access) :

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.

Fig. 1

Fig. 1

System configuration of IB system16)

Fig. 2

Fig. 2

Final volumetric polymerization shrinkage (vol.%) of composite resins according to light intensity. The shrinkage values were measured for 110sec (n=10).

Fig. 3

Fig. 3

Polymerization shrinkage of AF, Z1 and SF under 300mW/cm2 as a function of time (vol.%).

Fig. 4

Fig. 4

Rate of polymerization shrinkage of AF, Z1 and SF under 300mW/cm2 as a function of time (Rps : dvol.%/dsec).

Rps:rate of polymerization shrinkage.

Fig. 5

Fig. 5

Presumed ratio of P.T. & Rp and ratio of experimental P.T. & maxRp.

P.T.:peak time

Rp:rate of polymerization

maxRps:maximum rate of polymerization shrinkage

Table 1

Composite resins used in this study.

Table 1

Table 2

The experimental groups according to light intensity.(n=10)

Table 2

Table 3

Maximum rate of polymerization shrinkage (maxRps; dvol.%/ dsec) determined in the experiment.

Table 3

(The numbers in the parenthesis are standard deviations.)

Table 4

Peak time(sec) determined in experiment.

Table 4

(The numbers in the parenthesis are standard deviations.)

Table 5

Presumed ratio of Rp and P.T. and ratio of experimental P.T.

Table 5

P.T.:peak time

Rp:rate of polymerization