Warning: mkdir(): Permission denied in /home/virtual/lib/view_data.php on line 81

Warning: fopen(upload/ip_log/ip_log_2024-12.txt): failed to open stream: No such file or directory in /home/virtual/lib/view_data.php on line 83

Warning: fwrite() expects parameter 1 to be resource, boolean given in /home/virtual/lib/view_data.php on line 84
A new method to measure the linear polymerization shrinkage of composites using a particle tracking method with computer vision


Your browser does not support the NLM PubReader view.

Go to this page to see a list of supporting browsers.

A new method to measure the linear polymerization shrinkage of composites using a particle tracking method with computer vision

Article information

Restor Dent Endod. 2010;35(3):180-187
Publication date (electronic) : 2010 May 31
doi : https://doi.org/10.5395/JKACD.2010.35.3.180
In-Bog Lee, Sun-Hong Min, Deog-Gyu Seo, Sun-Young Kim, Youngchul Kwon
Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea.
Correspondence to: In-Bog Lee. Department of Conservative Dentistry & Dental Research Institute, School of Dentistry, Seoul National University 275-1 Yoengeon-Dong, Jongno-Gu, Seoul, 110-786, Korea. Tel: 82-2-2072-3953, Fax: 82-2-2072-3859, inboglee@snu.ac.kr
Received 2010 April 22; Revised 2010 April 25; Accepted 2010 April 26.

Abstract

Since the introduction of restorative dental composites, their physical properties have been significantly improved. However, polymerization shrinkage is still a major drawback. Many efforts have been made to develop a low shrinking composite, and silorane-based composites have recently been introduced into the market. In addition, many different methods have been developed to measure the polymerization shrinkage.

In this study, we developed a new method to measure the linear polymerization shrinkage of composites without direct contact to a specimen using a particle tracking method with computer vision. The shrinkage kinetics of a commercial silorane-based composite (P90) and two conventional methacrylate-based composites (Z250 and Z350) were investigated and compared. The results were as follows:

  1. The linear shrinkage of composites was 0.33-1.41%. Shrinkage was lowest for the silorane-based (P90) composite, and highest for the flowable Z350 composite.

  2. The new instrument was able to measure the true linear shrinkage of composites in real time without sensitivity to the specimen preparation and geometry.

Keywords: Composites; Silorane; Linear polymerization shrinkage; Computer vision; Particle tracking

References

1. Venhoven B.A.M., de Gee A.J., Davidson C.L. Polymerization contraction and conversion of light-curing BisGMA-based methacryate resins. Biomaterials 1993. 14871–875.
2. Ferracane JL. Developing a more complete understanding of stresses produced in dental composites during polymerization. Dent Mater 2005. 2136–42.
3. Ferracane JL. Buonocore Lecture. Placing dental composites-a stressful experience. Oper Dent 2008. 33247–257.
4. Lai J.H., Johnson A.E. Measuring polymerization shrinkage of photo activated restorative materials by a water filled dilatometer. Dent Mater 1993. 9139–143.
5. Penn R.W. A recording dilatometer for measuring polymerization shrinkage. Dent Mater 1986. 278–79.
6. de Gee A.J., Feilzer A.J., Davidson C.L. True linear polymerization shrinkage of unfilled resins and composites determined with a linometer. Dent Mater 1993. 911–14.
7. Sakaguchi R.L., Sasik C.T., Bunczak M.A., Douglas W.H. Strain gauge method for measuring polymerization contraction of composite restoratives. J Dent 1991. 19312–316.
8. Fano V., Ortalli I., Pizzi S., Bonanini M. Polymerization shrinkage of microfilled composites determined by laser beam scanning. Biomaterials 1997. 18467–470.
9. Labella R., Lambrechts P., van Meerbeek B., Vanherle G. Polymerization shrinkage and elasticity of flowable composites and filled adhesives. Dent Mater 1999. 15128–137.
10. Watts DC, Cash AJ. Determination of polymerization shrinkage kinetics in visible light-cured materials: methods development. Dent Mater 1991. 7281–287.
11. Lee MR, Cho BH, Son HH, Um CM, Lee IB. Influence of cavity dimension and restoration methods on the cusp deflection of premolars in composite restoration. Dent Mater 2007. 23288–295.
12. Park JK, Chang JH, Lee IB. How should composite be layered to reduce shrinkage stress: Incremental or bulk filling? Dent Mater 2008. 241501–1505.
13. Feilzer AJ, de Gee AJ, Davidson CL. Setting stress in composite resin in relation to configuration of the restoration. J Dent Res 1987. 661636–1639.
14. Lee IB, Cho BH, Son HH, Um CM, Lim BS. The effect of consistency, specimen geometry and adhesion on the axial polymerization shrinkage measurement of light cured composites. Dent Mater 2006. 221071–1079.
15. Lee SH, Chang J, Ferracane J, Lee IB. Influence of instrument compliance and specimen thickness on the polymerization shrinkage stress measurement of light-cured composites. Dent Mater 2007. 231093–1100.
16. Lee IB, Cho BH, Son HH, Um CM. A new method to measure the polymerization shrinkage kinetics of light cured composites. J Oral Rehabil 2005. 32304–314.
17. 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. 26134–140.
18. Ellakwa A, Cho NK, Lee IB. The effect of resin matrix composition on the polymerization shrinkage and rheological properties of experimental dental composites. Dent Mater 2007. 231229–1235.
19. Weinmann W, Thalacker C, Guggenberg R. Siloranes in dental composites. Dent Mater 2005. 2168–74.
20. Papadogiannis D, Kakaboura A, Palaghias G, Eliades G. Setting characteristics and cavity adaptation of low-shrinking resin composites. Dent Mater 2009. 251509–1516.
21. Calheiros FC, Sadek FT, Braga RR, Cardoso PE. Polymerization contraction stress of low-shrinkage composites and its correlation with microleakage in class V restorations. J Dent 2004. 32407–412.
22. Kleverlaan CJ, Feilzer AJ. Polymerization shrinkage and contraction stress of dental resin composites. Dent Mater 2005. 211150–1157.
23. Seo DG, Min SH, Lee IB. Effect of instrument compliance on the polymerization shrinkage stress measurements of dental resin composites. J Korean Acad Conserv Dent 2009. 34146–152.
24. Kwon Y, Lee IB. Polymerization shrink-age kinetics of silorane-based composites. J Korean Acad Conserv Dent 2010. 3551–58.

Article information Continued

Copyright © 2010 Korean Academy of Conservative Dentistry

Figure 1

Figure 1

Schematic diagram of computer vision system.

Figure 2

Figure 2

Specimen preparation for linear shrinkage measurement using computer vision.

Figure 3

Figure 3

A captured original image (left) and a binarized image (right) after filtering. The position of an object is determined by the area center method.

Figure 4

Figure 4

Algorithm to get the coordinate of an interesting particle from an image.

Figure 5

Figure 5

Linear shrinkage curves of composites as a function of time.

Figure 6

Figure 6

Linear shrinkage of composites at 10 min after curing.

Table 1

Composite resins used in this study.

Table 1

Table 2

Linear polymerization shrinkage measured and calculated volume shrinkage of composites at 10 min.

Table 2

Number in parenthesis is standard deviation.

Calculated volume shrinkage = 3× measured linear shrinkage.