Investigation of the surface of light-curing dental materials after pre-polymerization heating

   Despite the great variety and wide application of light-cured composite restorative materials for the treatment of hard tissue diseases, the issue of longevity of restorations remains relevant to this day. One of the criteria for the long-term durability of a composite restoration is the finish of the restoration. Poor polishing and surface roughness significantly reduce the
service life of the restoration and provide a good environment for biofilm adhesion, loss of luster of the restoration, and caries recurrence. Thus, methods affecting the reduction of surface relief in restorations remain a current issue.

   Aim. To evaluate the surface roughness and porosity of composite filling materials after pre-polymerization heating.

   Materials and methods. Sixty composite samples were prepared in the form of 1 mm thick, 1.2 cm diameter disks. The samples were divided into 2 groups depending on the presence of pre-polymerization heating. Atomic force microscopy (AFM) was used to measure the roughness and to visualize the surface morphology of the samples. Porosity was measured using a vacuum sputtering unit, and a scanning electron microscope was used to obtain micrographs of the sample.

   Results. The use of pre-polymerization heating of composite filling materials in dental practice will allow dentists to significantly reduce the expression of the relief of the composite restoration by reducing the roughness and pore volume in the matrix of the composite filling material, which will certainly optimize the finishing of the restoration.

   Conclusions. Pre-polymerization heating has a positive effect on the surface topography of the composite restoration, reducing its roughness and porosity, which improves the stage of finishing: obtaining a dry gloss, ensuring the duration of color stability, as well as reducing the adhesion of microorganisms to the filling material, thereby increasing the longevity of the composite restoration.

1. Firsova I.V., Makedonova Y.A., Marymova E.B. Comparative analysis of composite restoration in therapeutic dentistry. Volgograd Scientific and Medical Journal. 2017;1.

2. Silva MF, Dias MF, Lins-Filho PC, Silva CH, Guimarães RP. Color stability of Bulk-Fill composite restorations. J Clin Exp Dent. 2020 Nov 1;12(11):e1086-e1090. doi: 10.4317/jced.57579.

3. Nasim I., Neelakantan P., Sujeer R., Subbarao C.V.. Color stability of microfilled, microhybrid and nanocomposite resins – an in vitro study. J. Dent. 2010;38: e137-e142. doi: 10.1016/j.jdent.2010.05.020.

4. R Veena Kumari, Hema Nagaraj, Kishore Siddaraju, and Ramya Krishna Poluri. Evaluation of the effect of surface polishing, oral beverages and food colorants on color stability and surface roughness of nanocomposite resins/ J Int Oral Health. 2015 Jul; 7(7): 63-70.

5. Choi JW, Lee MJ, Oh SH, Kim KM. Changes in the physical properties and color stability of aesthetic restorative materials caused by various beverages. Dent Mater J. 2019 Feb 8;38(1):33-40. URL: https://yonsei.elsevierpure.com/en/publications/changes-in-the-physical-properties-and-color-stability-of-aesthet.

6. Mazzitelli C, Paolone G, Sabbagh J, Scotti N, Vichi A. Color Stability of Resin Cements after Water Aging. Polymers (Basel). 2023 Jan 27;15(3):655. doi: 10.3390/polym15030655. PMID: 36771956; PMCID: PMC9919001.

7. Rohym S, Tawfeek HEM, Kamh R. Effect of coffee on color stability and surface roughness of newly introduced single shade resin composite materials. BMC Oral Health. 2023 Apr 22;23(1):236. doi: 10.1186/s12903-023-02942-y.

8. Beltrami R, Ceci M, De Pani G, et al. Effect of different surface finishing/polishing procedures on color stability of esthetic restorative materials: A spectrophotometric evaluation. European Journal of Dentistry. 2018;12(1):49-56. doi:10.4103/ejd.ejd_185_17.

9. R Veena Kumari,1 Hema Nagaraj, 2 Kishore Siddaraju,3 and Ramya Krishna Poluri. Evaluation of the Effect of Surface Polishing, Oral Beverages and Food Colorants on Color Stability and Surface Roughness of Nanocomposite Resins. J Int Oral Health. 2015 Jul; 7(7): 63–70.

10. Avsar A, Yuzbasioglu E, Sarac D. The Effect of Finishing and Polishing Techniques on the Surface Roughness and the Color of Nanocomposite Resin Restorative Materials. Adv Clin Exp Med. 2015 Sep-Oct;24(5):881-90. URL: https://www.researchgate.net/publication/283741420_The_Effect_of_Finishing_and_Polishing_Techniques_on_the_Surface_Roughness_and_the_Color_of_Nanocomposite_Resin_Restorative_Materials.

11. Min JH, Kim BR, Kim BI. Optical detection of the potential for tooth discoloration from children's beverages by quantitative light-induced fluorescence technology. Photodiagnosis Photodyn Ther. 2021 Jun;34:102240. doi: 10.1016/j.pdpdt.2021.102240.