Surface roughness of experimental composite resins using confocal laser scanning microscope

Article information

Restor Dent Endod. 2008;33(1):1-8

Publication date (electronic) : 2008 January 31

doi : https://doi.org/10.5395/JKACD.2008.33.1.001

¹Department of Conservative Dentistry, Seoul National University Bundang Hospital, Korea.

²Department of Conservative Dentistry, School of Dentistry, Seoul National University, Korea.

³Dental Research Institute, Seoul National University, Korea.

Corresponding Author: Byeong-Hoon Cho. Department of Conservative Dentistry, School of Dentistry, Seoul National University, 28 Yeongeon-dong, Jongro-gu, Seoul, 110-749, Korea. Tel: 82-2-2072-3514, Fax: 82-2-764-3514, chobh@snu.ac.kr

Received 2007 September 18; Revised 2007 October 24; Accepted 2007 October 24.

Abstract

The purpose of this study was to evaluate the effect of a new resin monomer, filler size and polishing technique on the surface roughness of composite resin restorations using confocal laser scanning microscopy. By adding new methoxylated Bis-GMA (Bis-M-GMA, 2,2-bis[4-(2-methoxy-3-methacryloyloxy propoxy) phenyl] propane) having low viscosity, the content of TEGDMA might be decreased. Three experimental composite resins were made: EX1 (Bis-M-GMA/TEGDMA = 95/5 wt%, 40 mm nanofillers); EX2 (Bis-M-GMA/TEGDMA = 95/5 wt%, 20 mm nanofillers); EX3 (Bis-GMA/TEGDMA = 70/30 wt%, 40 mm nanofillers). Filtek Z250 was used as a reference.

Nine specimens (6 mm in diameter and 2 mm in thickness) for each experimental composite resin and Filtek Z250 were fabricated in a teflon mold and assigned to three groups. In Mylar strip group, specimens were left undisturbed. In Sof-lex group, specimens were ground with #1000 SiC paper and polished with Sof-lex discs. In DiaPolisher group, specimens were ground with #1000 SiC paper and polished with DiaPolisher polishing points. The Ra (Average roughness), Rq (Root mean square roughness), Rv (Valley roughness), Rp (Peak roughness), Rc (2D roughness) and Sc (3D roughness) values were determined using confocal laser scanning microscopy. The data were statistically analyzed by Two-way ANOVA and Tukey multiple comparisons test (p = 0.05).

The type of composite resin and polishing technique significantly affected the surface roughness of the composite resin restorations (p < 0.001). EX3 showed the smoothest surface compared to the other composite resins (p < 0.05). Mylar strip resulted in smoother surface than other polishing techniques (p < 0.05).

Bis-M-GMA, a new resin monomer having low viscosity, might reduce the amount of diluent, but showed adverse effect on the surface roughness of composite resin restorations.

Keywords: Bis-M-GMA; confocal laser scanning microscopy; filler size; new resin monomer; surface roughness

Notes

This work was supported by a grant from the Ministry of Health and Welfare of Korea (Grant No. 03-PJ1-PG1-CH09-0001).

References

1. Lu H, Roeder LB, Powers JM. Effect of polishing systems on the surface roughness of microhybrid composites. J Esthet Restor Dent 2003. 15297–304.

2. van Noort R, Davis LG. The surface finish of composite resin restorative materials. Br Dent J 1984. 157360–364.

3. Toledano M, De La Torre FJ, Osorio R. Evaluation of two polishing methods for resin composites. Am J Dent 1994. 7328–330.

4. Chan KC, Fuller JL, Hormati AA. The ability of foods to stain two composite resins. J Prosthet Dent 1980. 43542–545.

5. Bouvier D, Duprez JP, Lissac M. Comparative evaluation of polishing systems on the surface of three aesthetic materials. J Oral Rehabil 1997. 24888–894.

6. Kaplan BA, Goldstein GR, Vijayaraghvan TV, Nelson IK. The effect of three polishing systems on the surface roughness of four hybrid composites; a profilometric and scanning electron microscopy study. J Prosthet Dent 1996. 7634–38.

7. Turssi CP, Saad JRC, Duarte SLL, Rodirigues AL. Composite surfaces after finishing and polishing techniques. Am J Dent 2000. 13136–138.

8. Lee JY, Shin DH. Surface roughness of universal composites after polishing procedures. J Korean Acad Conserv Dent 2003. 28369–377.

9. Fruits TJ, Miranda FJ, Coury TL. Effects of equivalent abrasive grit sizes utilizing differing polishing motions on selected restorative materials. Quintessence Int 1996. 27279–285.

10. Roeder LB, Tate WH, Powers JM. Effect of finishing and polishing procedures on the surface roughness of packable composites. Oper Dent 2000. 25534–543.

11. Marigo L, Rizzi M, La Torre G, Rumi G. 3-D surface profile analysis: different finishing methods for resin composites. Oper Dent 2001. 26562–568.

12. Terry DA. Direct applications of a nanocomposite resin system; part 1- the evolution of contemporary composite materials. Pract Proced Aesthet Dent 2004. 16417–422.

13. Kalachandra S, Sankarapandian M, Shobha HK, Taylor DF, McGrath JE. Influence of hydrogen bonding on properties of Bis-GMA analogs. J Mater Sci Mater Med 1997. 8283–286.

14. Anseth KS, Newman SM, Bowman CN. Polymeric dental composites: properties and reaction behavior of multimethacrylate dental restorations. Adv Polym Sci 1995. 122177–217.

15. Braden M. The formulation of composite filling materials. Oper Dent 1978. 397–102.

16. Kim JW, Kim LU, Kim CK, Cho BH, Kim OY. Characteristics of novel dental composites containing 2,2-bis[4-(2-methoxy-3-methacryloxy-propoxy) phenyl] propane as a base resin. Biomacromolecules 2006. 7154–160.

17. Bae JH, Kim YK, Yoon PY, Lee MA, Cho BH. Effect of a new resin monomer on the microleakage of composite resin restorations. J Korean Acad Conserv Dent 2007. 32469–475.

18. González-Cabezas C, Fontana M, Dunipace AJ, Li Y, Fischer GM, Proskin HM, Stookey GK. Measurement of enamel remineralization using microradiography and confocal microscopy. A correlational study. Caries Res 1998. 32385–392.

19. Al-Nawas B, Grotz KA, Götz H, Heinrich G, Rippin TG, Stender TE, Duschner H, Wagner W. Validation of three-dimensional surface characterising methods: scanning electron microscopy and confocal laser scanning microscopy. Scanning 2001. 23227–231.

20. Al-Shammery HA, Bubb NL, Youngson CC, Fasbinder DJ, Wood DJ. The use of confocal microscopy to assess surface roughness of two milled CAD-CAM ceramics following two polishing techniques. Dent Mater 2007. 23736–741.

21. Ross M, Romrell LJ, Kaye GI. Histology. A test and atlas 1995. 3rd Edth ed. Williams & Wikins; 12–13.

22. Mohan B, Kandaswamy D. A confocal microscopic evaluation of resin-dentin interface using adhesive systems with three different solvents bonded to dry and moist dentin in vitro study. Quintessence Int 2005. 36511–521.

23. Banerjee A, Boyde A. Autofluorescence and mineral content of carious dentine: scanning optical and backscattered electron microscopic studies. Caries Res 1998. 32219–226.

24. Hachiya Y, Iwaku M, Hosoda H, Fusayama T. Relation of finish to discoloration of composite resins. J Prosthet Dent 1984. 52811–814.

25. Okazaki M, Douglas WH. Comparison of surface layer properties of composite resin by ESCA, SEM and X-ray diffractiometry. Biomaterials 1984. 5284–290.

26. Lee IB, Lee JH, Cho BH, Son HH, Lee ST, Um CM. Rheological properties of resin composites according to the change of monomer and filler compositions. J Korean Acad Conserv Dent 2004. 29520–531.

27. Rong MZ, Zhang MQ, Pan SL, Friedrich K. Interfacial effects in polypropylene-silica nanocomposites. J Appl Polym Sci 2004. 921771–1781.

Article information Continued

(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.

Figure 1

Confocal laser scanning micrography of EX3 Sof-lex group (× 200).

Figure 2

3D image of EX3 Sof-lex group obtained using confocal laser scanning micrography (× 200).

Figure 3

Cross-sectional profile obtained from the intersection line in Figure 1 & 2.

Figure 1

Confocal laser scanning micrography of EX3 Sof-lex group (× 200).

Figure 2

3D image of EX3 Sof-lex group obtained using confocal laser scanning micrography (× 200).

Table 1

The composition of experimental composite resins (Unit: wt%)

The numbers were weight percentage of the composition within each experimental resin.

Table 2

Polishing tools and their polishing protocols

Table 3

The Ra, Rq, Rv, Rp, Rc, and Sc values of experimental composite resins according to the polishing techniques

† The numbers in parentheses are the standard deviations. (n = 21)

¶ Means within same columns with different superscript letters in each parameter are significantly different (p < 0.05), and means within same rows with different superscript numbers in each parameter are significantly different (p < 0.05).

§ The values of Filtek Z250 were also measured as a reference.