Surface roughness of a resin composite

Rugosidade superficial de resina composta

ABSTRACT

Objective:

The aim of the present study was to evaluate the surface roughness (Ra) of the Z-350 resin composite following immersion in different media (distilled water, coca-cola, coffee, black tea and red wine).

Methods:

Fifty specimens of resin composite measuring 10 mm x 2 mm were prepared. Polymerization was performed using the conventional method (40 s). Each specimen was immersed for one hour per day. Evaluations were performed at baseline as well as after three, six, nine and 12 months. Three Ra readings were taken in opposite directions at each evaluation using a roughness meter. Mean Ra values were subjected to analysis of variance (ANOVA) followed by Tukey's test (p < 0.05).

Results:

^{_{A significant increase in Ra was found in the specimens submitted to coffee, coca-cola(r) and black tea between baseline and the three-month evaluation. Variance was also found among the remaining evaluation times (3 months to 12 months), but the differences did not achieve statistical significance. No statistically significant differences in Ra were found among evaluation times in the specimens submitted to red wine or distilled water.}}

Conclusion:

Based on the present findings, coca-cola, coffee and black tea exert an influence on the surface roughness of resin composites.

Indexing terms:
Beverages; Immersion; Resin composite; Tooth erosion.

RESUMO

Objetivo:

Avaliar a rugosidade da superfície (Ra) do Z-350 resina composta após imersão em diferentes meios (água destilada, coca-cola, café, chá preto e vinho tinto).

Métodos:

Foram preparados cinquenta espécimes de resina composta medindo 10 mm x 2 mm. A polimerização foi realizada através do método convencional (40 s). Cada espécime foi imerso durante uma hora por dia. As avaliações foram realizadas na linha de base, bem como após três, seis, nove e 12 meses. Três leituras Ra foram levados em direções opostas em cada avaliação, utilizando um medidor de rugosidade. Os valores médios de Ra foram submetidos a análise de variância (ANOVA) seguido pelo teste de Tukey (p <0,05).

Resultados:

Um aumento significativo na Ra foi encontrada nas amostras submetidas ao café, coca-Cola^(r) e chá preto entre o início e a avaliação de três meses. Variância também foi encontrado entre as épocas de avaliação restantes (3 meses a 12 meses), mas as diferenças não atingiram significância estatística. Não houve diferenças estatisticamente significativas na Ra encontrados entre os momentos de avaliação nos casos submetidos ao vinho tinto ou água destilada.

Conclusão:

Com base nos achados, coca-cola, café e chá preto exercem uma influência sobre a rugosidade superficial de resinas compostas.

Termos de indexação:
Bebidas; Imersão; Resinas compostas; Erosão dentária.

INTRODUCTION

The durability of restorative materials in the oral cavity is related to their resistance to dissolution and disintegration^1-4. Resin composites are frequently subjected to harm in the oral cavity in the form of abrasion (brushing), attrition (diet and parafunctional habits) and erosion (citrus drinks, fruit, soft drinks)^5-7.

The erosive activity of beverages affects the composite restorations, leaving a rough surface that influences the optical properties of the material^8-9, and facilitates the buildup of bacterial plaque and degradation of the surface of the restoration^10-11. Erosion leads to a reduction in hardness and wear resistance^1-4. Moreover, surface roughness can cause gingival irritation and increases the risk of secondary caries^8,10. Thus, the surface characteristics of a resin composite contribute to the clinical longevity of a restoration¹².

Although a number of studies have addressed the effects of different solutions on the surface of resin composites^13-15, few have performed long-term evaluations. Thus, the aim of the present study was to evaluate the surface roughness (Ra) of a resin composite submitted to immersion in different beverages one hour per day for three, six, nine and 12 months.

METHODS

Fifty specimens were prepared with the Z-350^(r) resin composite (3M ESPE, Saint Paul, USA) their technical specifications are displayed in Table 1. Each specimen measured 10 mm x 2 mm. After inserting the material, a strip of polyester (Fava, Pirituba, Brazil) was placed over the matrix and the tip of the curing light was pressed against the assembly to form a flat surface on the specimens. Polymerization was performed using the conventional method (Elipar Free Light II / 3M Espe, Seefeld, Germany, 1200 mW/cm² for 40s). The specimens were submitted to immersion in different media distilled water (Asfer, São Caetano do Sul, Brazil), coca-cola^(r) (Coca-Cola^(r), Petrópolis, Brazil), coffee (Três Corações, Santa Luzia, Brazil), black tea (Moinhos Unidos, Curitiba, Brazil) and red wine (Canção, Flores da Cunha, Brazil), for one hour per day and their technical specifications are displayed in Table 2. The specimens were subsequently washed and returned to their recipients with distilled water at 37 ± 1 °C for 23 hours.

Table 1
Resin composite.

Material	Particles	Particle size	Bulk (% weight)	Matrix
Filtek Z350	Nonparticle silica (not agglomerated/ not aggregated) and nanoclusters of zirconia/silica	Nanoparticles of silica 20 nm Zirconia/silica: 5-20 nm nanoclusters: 0.6 to 1.4 µm	78.5 %	Bis-Gma, Bis-Ema, UDMA and TEGDMA

Table 2
Study groups.

Material	Particles	Matrix
Distilled water	5.5
Coca-Cola	2.7	Carbonated water, sugar, kola nut extract, caffeine, caramel coloring IV, INS 338 acidifier and natural aroma
Coffee	5.01	Caffeine, theobromine, caffeic acid, theophylline, vanillic acid, benzoic acid
Black tea	5.8	Leaves and buds of black tea (Camelia sinensis).
Red wine	3.7	Water, sugar, ethyl alcohol, grape juice, tartaric acid; alcohol content: 10.4%

At predetermined times [baseline (T1), 3 months (T2), 6 months (T3), 9 months (T4) and 12 months (T5)], three Ra readings were taken in opposite directions using a roughness meter (Surftest SJ-301 Mitutoyo, Kanagawa, Japan). Statistical analysis was performed using Statistical Package for Social Sciences (SPSS for Windows, version 18.0, SPSS Inc, Chicago, USA), mean Ra values were subjected to analysis of variance (ANOVA) followed by Tukey's test (p < 0.05).

RESULTS

Figure 1 displays the mean Ra and standard deviation values. A significant increase in Ra was found in the specimens submitted to coffee, coca-cola^(r) and black tea between baseline and the three-month evaluation. Variance was also found among the remaining evaluation times (3 months to 12 months), but the differences did not achieve statistical significance. No statistically significant differences in Ra were found among evaluation times in the specimens submitted to red wine or distilled water.

Figure 1
Average of roughness and e de standards dos groups avalied. Note: Mean Ra values were subjected to analysis of variance (ANOVA) followed by Tukey's test (p < 0.05).

DISCUSSION

It is important to maintain a smooth surface on dental restorations to avoid problems such as changes in color and brightness and minimize the risk of secondary caries^9,11. A rough surface facilitates the buildup of bacterial plaque and can affect periodontal health¹⁶. It is therefore ideal to make the surface of a composite resin as smooth as possible to obtain optimum clinical performance. However, the frequent ingestion certain substances can lead to an increase in surface roughness, as demonstrated in the present investigation.

A number of studies have evaluated the effect of different beverages on the surface of resin composites^13,15,17-19, but few have performed long-term evaluations, likely due to the difficulties such as daily changes of the immersion media.

In the present study, no statistically significant differences among evaluation times were found for the samples submitted to red wine, despite the low pH (3.7) and alcohol content (10.4%) of this medium. Alcohol is a great solvent of polymer chains and high concentrations of this substance (50 to 75%) soften the surface of a resin composite, leading to increased roughness^1,20-24. The lack of a significant difference in this group was likely due to the low concentration of alcohol in red wine.

The significant difference found in the specimens submitted to coca-cola^(r) (pH 2.7) was likely due to the phosphoric acid and sugars in the chemical composition of this beverage, causing erosion to the surface of the resin composite^17,19. Significant differences in Ra were also found in the specimens submitted to coffee and black tea beginning at three months. While the respective pH values are 5.0 and 5.8, the composition of these beverages may have been the cause of erosion, as these natural substances have different long-chain organic acids¹⁸ that can dissolve and erode restorative materials^17-18,25.

Differences in pH did not influence the results as much as the presence of acids in the substances evaluated. Indeed, a more acidic pH does not appear indicate greater erosive potential²⁶. Erosion depends on the combined effect of physicochemical properties, total amount of acid, mineral content and titratable acidity^26-27.

Further investigations should be performed addressing the frequency of intake as well as the physicochemical characteristics of these beverages, which can influence changes in the surface roughness of resin composites. Although the present in vitro findings do not allow the prediction of clinical performance, the data serve as a warning to dentists regarding problems involving rough surfaces on resin composites, which can be caused by different beverages.

CONCLUSION

Based on the present findings, coca-cola^(r), coffee and black tea exert an influence on the surface roughness of resin composites.

Acknowledgements

The authors thank FAPEMIG and CAPES for the support.

REFERENCES

• ¹
  Ferracane JL. Effects hygroscopic and hydrolytic in dental polymer networks. Dent Mater. 2006;22(3):211-22. doi:10.1016/j.dental.2005.05.005
  » https://doi.org/10.1016/j.dental.2005.05.005
• ²
  Silva MA, Fardin AB, Vasconcellos RC, Santos LM, Tonholo J, Silva JG Jr,et al. Analysis of surface roughness and surface hardness of a dental composite using atomic force microscopy and hardness testing. Microsc Microanal. 2011;17(3):446-51. doi: 10.1017/S1431927611000250
  » https://doi.org/10.1017/S1431927611000250
• ³
  Soares-Geraldo D, Scaramucci T, Steagall-Jr W, Braga SR, Sobral MA. Interaction between staining and degradation of a composite resin in contact with colored foods. Braz Oral Res. 2011;25(4):369-75. doi.org/10.1590/S1806-83242011000400015
  » https://doi.org/10.1590/S1806-83242011000400015
• ⁴
  Miranda DA, Bertoldo CE, Aguiar FH, Lima DA, Lovadino JR. Effects of mouthwashes on Knoop hardness and surface roughness of dental composites after different immersion times. Braz Oral Res. 2011;25(2):168-73. doi: 10.1590/S1806-83242011000200012
  » https://doi.org/10.1590/S1806-83242011000200012
• ⁵
  Gohring TN, Besek MJ, Schmidlin PR. Attricional wear and abrasive surface alternations of composite resin materials in vitro. J Dent. 2002;30(2-3):119-27. doi: 10.1016/S0300-5712(02)00007-6
  » https://doi.org/10.1016/S0300-5712(02)00007-6
• ⁶
  Briso AL, Caruzo LP, Guedes AP, Catelan A, Santos PH. In vitro evaluation of surface roughness and microhardness of restorative materials submitted to erosive challenges. Oper Dent. 2011;36(4):397-402. doi: 10.2341/10-356-L
  » https://doi.org/10.2341/10-356-L
• ⁷
  Kooi TJ, Tan QZ, Yap AU, Guo W, Tay KJ, Soh MS. Effects of food-simulating liquids on surface properties of giomer restoratives. Oper Dent. 2012;37(6):665-71. doi: 10.2341/11-419-L
  » https://doi.org/10.2341/11-419-L
• ⁸
  Yesil ZD, Alapati S, Johnston W, Seqhi RR. Evaluation of the wear resistance of new nanocomposite resin restorative materials. J Prosthet Dent. 2008;99(6):435-43. doi: 10.1016/S0022-3913(08)60105-5
  » https://doi.org/10.1016/S0022-3913(08)60105-5
• ⁹
  Azer SS, Hague AL, Johnston WM. Effect of bleaching on tooth discolouration from food colourant in vitro. J Dent. 2011;39(Suppl 3):e52-6. doi: 10.1016/j.jdent.2011.09.006
  » https://doi.org/10.1016/j.jdent.2011.09.006
• ¹⁰
  Paravina RD, Roeder L, Lu H, Vogel K, Powers JM. Effect of finishing and polishing procedures for the surface roughness, brightness and color of the resin based composites. J Am Dent. 2004;17:262-66.
• ¹¹
  Murakami JT, Umetsubo LS, Valera MC, Araújo MAM. Rugosidade superficial de resinas compostas após utilização de jato de bicarbonato ou pasta de pedra-pomes. RGO, Rev Gaúch Odontol. 2006;54(1):7-10.
• ¹²
  Lin CY, Lee SY, Huang HM, Keh ES, Lin CT. Stability of dental composites in organic solutions simulating oral environment. J Dent Res. 1997;76:321.
• ¹³
  Yanikoglu N, Duymus ZY, Yilmaz B. Effects of different solutions on the surface hardness of composite materials. Dent Mater. 2009;28(3):344-51. doi: 10.4012/dmj.28.344
  » https://doi.org/10.4012/dmj.28.344
• ¹⁴
  Mundim FM, Garcia Lda F, Pires-de-Souza FC. Effect of staining solutions and repolishing on color stability of direct composites. J Appl Oral Sci. 2010;18(3):249-54. doi: 10.1590/S1678-77572010000300009
  » https://doi.org/10.1590/S1678-77572010000300009
• ¹⁵
  Hamouda IM. Effects of different drinks on the hardness, roughness and solubility of esthetic restorative materials. J Esthet Restor Dent. 2011;23(5):315-22. doi: 10.1111/j.1708-8240.2011.00453.x
  » https://doi.org/10.1111/j.1708-8240.2011.00453.x
• ¹⁶
  Kawai K, Urano M. Adherence of plaque components to different restorative materials. Oper Dent. 2001;26(4):396-400.
• ¹⁷
  Bansal K, Acharya SR, Saraswathi V. Effect of alcoholic and non-alcoholic beverages on color stability and surface roughness of resin composites: An in vitro study. J Conserv Dent. 2012;15(3):283-8. doi: 10.4103/0972-0707.97961
  » https://doi.org/10.4103/0972-0707.97961
• ¹⁸
  Gouvea CV, Bedran LM, Faria MA, Cunha-Ferreira N. Surface roughness and translucency of resin composites after immersion in coffee and soft drink. Acta Odontol Latinoam. 2011;24(1):3-7.
• ¹⁹
  Tuncer D, Karaman E, Firat E. Does the temperature of beverages affect the surface roughness, hardness, and color stability of a composite resin? Eur J Dent. 2013;7(2):165-71. doi: 10.4103/1305-7456.110161
  » https://doi.org/10.4103/1305-7456.110161
• ²⁰
  Cavalcanti AN, Mitsui FH, Ambrosano GM, Mathias P, Marchi GM. Effect of different mouthrinses on Knoop hardness of a restorative composite. Am J Dent. 2005;18(6):338-40.
• ²¹
  Sarret DC, Coletti DP, Peluso AR. The effect of alcoholic beverages on composite wear. Dent Mater. 2000;16(1):62-7. doi: 10.1016/S0109-5641(99)00088-3
  » https://doi.org/10.1016/S0109-5641(99)00088-3
• ²²
  Alencar E Silva Leite ML, Cunha Medeiros E Silva FD, Meireles SS, Duarte RM, Andrade AK. The effect of drinks on color stability and surface roughness of nanocomposites. Eur J Dent. 2014;8(3):330-6. doi: 10.4103/1305-7456.137640
  » https://doi.org/10.4103/1305-7456.137640
• ²³
  Festuccia MSCC, Garcia LFR, Cruvinel DR, Pires-De-Souza FCP. Color stability, surface roughness and microhardness of composites submitted to mouthrinsing action. J Appl Oral Sci. 2012;20(2):200-5. doi: 10.1590/S1678-77572012000200013
  » https://doi.org/10.1590/S1678-77572012000200013
• ²⁴
  Wongkhantee S, Patanapiradej V, Maneenut C, Tantbirojn D. Effect of acidic food and drinks on surface hardness of enamel, dentine, and tooth-coloured filling materials. J Dent. 2006;34(3):214-20. doi: 10.1016/j.jdent.2005.06.003
  » https://doi.org/10.1016/j.jdent.2005.06.003
• ²⁵
  Gonçalves GK, Guglielmi CA, Corrêa FN, Raggio DP, Corrêa MS. Erosive potential of different types of grape juices. Braz Oral Res. 2012;26(5):457-63. doi: 10.1590/S1806-83242012005000015
  » https://doi.org/10.1590/S1806-83242012005000015
• ²⁶
  Lussi A, Jaeggi T. Erosion - diagnosis and risk factors. Clin Oral Investig. 2008;12(Suppl 1):S5-13. doi: 10.1007/s00784-007-0179-z
  » https://doi.org/10.1007/s00784-007-0179-z
• ²⁷
  Featherstone JD, Lussi A. Understanding the chemistry of dental erosion. Monogra Oral Sci. 2006;20:66-76. doi: 10.1159/000093351
  » https://doi.org/10.1159/000093351

Publication Dates

• Publication in this collection
  Mar 2016

History

• Received
  16 Nov 2014
• Reviewed
  10 Dec 2014
• Accepted
  14 May 2015