COPPER NANOPARTICLES CONTAINING ADHESIVE IMPROVES ANTIMICROBIAL, MECHANICAL AND ADHESIVE PROPERTIES HANZEN, T.A.*; GUTIÉRREZ, M.F.; MALAQUIAS, P.; HASS, V.; MATOS, T.P.; LOURENÇO, L.; REIS, A.; LOGUERCIO, A.D.; FARAGO, P.V. State University of Ponta Grossa, Ponta Grossa, PR, Brazil
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INTRODUCTION Recently, composite resins have become the most used restorative material at the expense of increasing aesthetic demand1,2,3,4. Although they have wide use and significant scientific development, some limitations are perceived, such as their durability in vivo5,6. In order to solve such problems, the incorporation of copper nanoparticles into adhesive systems has a potentially bactericidal effect, although the antimicrobial properties are poorly exploited7,8,9,10,11,12 and require further studies, as well as the ideal concentration to be added, in order to express antimicrobial activity and to produce stable bonding interfaces to the dentin, without compromising other mechanical properties.
OBJECTIVES To evaluate the effect of addition of copper nanoparticles (CN) at different concentrations into an etch-and-rinse adhesive (ER) on antimicrobial activity (AMA), knoop microhardness (KNH), in vitro degree of conversion (DC-d), in situ degree of conversion (DC-i), as well as immediate (IM) and 1-year (1Y) resin-dentine bond strength (μTBS) and nanoleakage (NL).
METHODS Knoop microhardness
Degree of conversion (DC-d)
Antimicrobial activity
Nanoleakage
Resin-dentine bond strength
Degree of conversion (DC-i)
Sequência para teste RMT
RESULTS Table 1. Mean values and standard deviation of bacterial inhibition halo sizes (mm) observed by different copper-containing adhesives against S. mutans (*).
Adhesive
Copper (%) Measures of inhibition halo (mm) Standard deviation
0 (CT)
0.0075
0.015
0.060
4.94 A
7.63 B
8.22 B
9.08 B
0.47
1.03
0.96
0.63
Table 2. Means and respective standard deviations of knoop microhardness (KNH) and degree of conversion (DC,%) obtained in each experimental condition (*).
0.1
0.5
10.81 C 11.54 C 0.90
0.81
1 11.94 C 0.47
0% (control) 0.0075% 0.015% 0.060% 0.1% 0.5% 1%
KNH 5.47 ± 0.49 A 5.73 ± 0.22 A,B 5.77 ± 0.24 A,B 6.77 ± 0.14 C,D 7.03 ± 0.12 D,E 7.53 ± 0.17 E 6.33 ± 0.10 B,C
DC-d 95,97 ± 0.26 a 94.95 ± 0.88 a 93.27 ± 0.08 a 94.31 ± 0.49 a 92.53 ± 1.21 a 92.56 ± 0.68 a 72.64 ± 3.06 b
DC-i 96.17 ± 1.79 96.87 ± 0.45 95.33 ± 0.50 95.36 ± 1.55 94.82 ± 1.12 93.50 ± 2.56 85.63 ± 3.42
A A A A A A B
Table 3. Averages and the respective standard deviations of bond strength (μTBS, MPa) and nanoinfiltration (NL,%), obtained in each experimental condition. Adhesive
Representative images of resin - dentin interfaces bonded with amber at the immediate moment (A - G) and after 1 year storage in water (H - N), according to the different experimental conditions. In the immediate time, only a few areas of silver nitrate uptake within HL (A-G) were observed (white spots indicated by the white pointer). After one year, an increase in silver nitrate absorption was observed, mainly in the control group. In the copper-containing (I-N) groups the silver nitrate deposition was lower than the control group (H) (Co = compound, HL = hybrid layer and De = dentin).
0%(controle) 0.0075% 0.015% 0.060% 0.1% 0.5% 1%
μTBS IM 34.58 ± 2.99 A 39.37 ± 1.76 A,B 40.35 ± 3.03 A,B 39.18 ± 1.52 A,B 42.82 ± 1.92 B,C 50.64 ± 3.10 D 37.37 ± 4.70 A,B
NL 1Y 26.59 ± 1.01 E 40.37 ± 2.18 A,B 40.08 ± 2.16 A,B 42.36 ± 2.78 B,C 43.03 ± 0.63 B,C,D 48.60 ± 2.45 C,D 39.63 ± 2.95 A,B
IM 17.51 ± 2.66 a 11.09 ± 3.48 a,b,c 10.91 ± 2.30 a,b,c 10.56 ± 1.05 a,b,c 8.99 ± 0.33 b,c 4.51 ± 1.91 c 5.88 ± 2.49 c
1Y 29.71 ± 4.59 d 13.89 ± 3.15 a,b 13.03 ± 5.10 a,b 12.90 ± 2.35 a,b 9.58 ± 0.84 b,c 6.67 ± 1.98 c 9.31 ± 2.29 b,c
CONCLUSIONS The addition of CN in concentrations up to 0.5 wt.% in a ER adhesive may be an alternative to provide antimicrobial properties and increase the immediate bonding properties of dentin, without reducing the mechanical properties of the formulations, and prevent the degradation of the adhesive interface.
REFERENCES 1.Christensen GJ. Should resin-based composite dominate restorative dentistry today? Journal of american dental association. 2010; Dec;141(12):1490-3. 2.Lynch CD, Opdam NJ, Hickel R, Brunton PA, Gurgan S, Kakaboura A, et al. Guidance on posterior resin composites: Academy of Operative Dentistry - European Section. Journal of dentistry. 2014; Apr;42(4):377-83. 3.Rasines Alcaraz MG, Veitz-Keenan A, Sahrmann P, Schmidlin PR, Davis D, Iheozor-Ejiofor Z. Direct composite resin fillings versus amalgam fillings for permanent or adult posterior teeth. The Cochrane database of systematic reviews. 2014;3:Cd005620. 4.Moraschini V, Fai CK, Alto RM, Dos Santos GO. Amalgam and resin composite longevity of posterior restorations: A systematic review and meta-analysis. Journal of dentistry. 2015; Sep;43(9):1043-50.
