Paper: Antibacterial dental composites reinforced by tunicate cellulose whiskers (AADR Annual Meeting (March 21-24, 2012))

Saturday, March 24, 2012: 8 a.m. - 9:30 a.m.

Presentation Type: Oral Session

X. XU, R. WU, J. ZHANG, Y. WANG, S. COSTIN, Y. FAN, and J. HAGAN, Comprehensive Dentistry and Biomaterials, Louisiana State University, New Orleans, LA

Objectives: To formulate and characterize experimental antibacterial dental composites reinforced by tunicate cellulose whisker. Methods: Tunicate cellulose whiskers (TCW) were extracted from tunicate (Styela clava) according to a report by Weder et al (Polym. Chem., 2010; 1: 1237). Then TCW were treated with methacryloyl chloride and triethylamine in chloroform for 6h. The resulting slurry is quenched by water and dialyzed in water for 2d, and lyophilized for 24h. Experimental composites were formulated with 30wt% monomers (BisGMA/EBPDMA/HDDMA=11.6/11.6/5.8) and 70wt% fillers. Antibacterial composites contain 5% of synthesized antibacterial monomer (AM) or 5% chlorhexidine diacetate (CHX) (Table 1). All materials contain 1% photoinitiators. Bar specimens (2x2x25mm, n=12) were prepared in stainless steel molds by light cure 3x40s on each side and stored in deionized water for 24h at 37^oC. Flexural strength and modulus were tested using a three-point-bending method on MTS 858 tesing machine. The data were analyzed ANOVA and post hoc Tukey-B tests.

Results:

Table 1. Compositions and mechanical properties of experimental composites (Mean±SD).

Antibacterial
Agents

Fillers (wt%)

Mechanical Properties

Glass Filler

TC
Whiskers

Flexure Strength
(MPa)

Flexural Modulus
(MPa)

0

70

0

99.03±15.34^b,c,d

6487.5±590.4^B

0

65

5

107.37±11.85^b,c

5580.9±525.3^E

0

60

10

127.88±12.24^a

7816.9±595.7^C

0

55

15

134.24±9.88^a

8095.3±461.0^B,^C

0

50

20

94.37±10.87^c,d

6909.3±886.7^D

CHX 5

70

0

72.18±11.77^e

6754.5±660.7^D

CHX 5

65

5

104.44±12.50^b,c

9400.1±934.2^A

AM 5

70

0

87.45±11.32^d,e

6412.1±582.7^D,E

AM 5

65

5

111.16±12.78^b

8993.9±614.4^A,B

The groups with the same letter have no significant difference (p>0.05).

Adding 5% CHX decreases the flexural strength of the composite (p<0.05). The flexural strength and modulus of experimental dental composites increase significantly (p<0.05) with increasing amount (up to 15%) of TCW.

Conclusions: Antibacterial composites reinforced by tunicate cellulose whiskers can have same or better mechanical properties compared with control. Supported by the Brown Foundation and NIH/NIDCR grant 5R01DE019203-3.

This abstract is based on research that was funded entirely or partially by an outside source: NIH/NIDCR 5R01DE019203-3

Keywords: Antimicrobials, Composites and Mechanical properties

See more of: Reinforced Resin-composites and Impression Materials
See more of: Dental Materials 7: Polymer-based Materials-Physical Properties and Performance

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Antibacterial Agents	Fillers (wt%)		Mechanical Properties
Antibacterial Agents	Glass Filler	TC Whiskers	Flexure Strength (MPa)	Flexural Modulus (MPa)
0	70	0	99.03±15.34^b,c,d	6487.5±590.4^B
0	65	5	107.37±11.85^b,c	5580.9±525.3^E
0	60	10	127.88±12.24^a	7816.9±595.7^C
0	55	15	134.24±9.88^a	8095.3±461.0^B,^C
0	50	20	94.37±10.87^c,d	6909.3±886.7^D
CHX 5	70	0	72.18±11.77^e	6754.5±660.7^D
CHX 5	65	5	104.44±12.50^b,c	9400.1±934.2^A
AM 5	70	0	87.45±11.32^d,e	6412.1±582.7^D,E
AM 5	65	5	111.16±12.78^b	8993.9±614.4^A,B

1201 Antibacterial dental composites reinforced by tunicate cellulose whiskers