US EPA

4959249 

Journal Article 

Fabrication and evaluation of Bis-GMA/TEGDMA dental resins/composites containing halloysite nanotubes 

Chen, Q; Zhao, Y; Wu, W; Xu, T; Fong, H 

2012 

Yes 

Dental Materials
ISSN: 0109-5641
EISSN: 1879-0097 

28 

10 

1071-1079 

English 

22796038 

10.1016/j.dental.2012.06.007 

WOS:000308469300011 

OBJECTIVE: To investigate the reinforcement of Bis-GMA/TEGDMA dental resins (without conventional glass filler) and the corresponding composites (with conventional glass filler) containing varied mass fractions of halloysite nanotubes (HNTs).

METHODS: Three dispersion methods were studied to separate the silanized halloysite as individual HNTs and to uniformly distribute them into dental matrices. Photopolymerization induced volumetric shrinkage was measured by using a mercury dilatometer. Real time near infrared spectroscopy was adopted to study the degree of vinyl double bond conversion and the photopolymerization rate. Mechanical properties of the composites were tested by a universal mechanical testing machine. Analysis of variance (ANOVA) was used for the statistical analysis of the acquired data. Morphologies of halloysite/HNTs and representative fracture surfaces of the reinforced dental resins/composites were examined by SEM and TEM.

RESULTS: Impregnation of small mass fractions (e.g., 1% and 2.5%) of the silanized HNTs in Bis-GMA/TEGDMA dental resins/composites improved mechanical properties significantly; however; large mass fractions (e.g., 5%) of impregnation did not further improve the mechanical properties. The impregnation of HNTs into dental resins/composites could result in two opposite effects: the reinforcing effect due to the highly separated and uniformly distributed HNTs, and the weakening effect due to the formation of HNT agglomerates/particles.

SIGNIFICANCE: Uniform distribution of a small amount of well-separated silanized HNTs into Bis-GMA/TEGDMA dental resins/composites could result in substantial improvements on mechanical properties.