PMID- 12808590
OWN - NLM
STAT- MEDLINE
DCOM- 20030827
LR  - 20200930
IS  - 1552-4973 (Print)
IS  - 1552-4973 (Linking)
VI  - 66
IP  - 1
DP  - 2003 Jul 15
TI  - Effect of admixed high-density polyethylene (HDPE) spheres on contraction stress 
      and properties of experimental composites.
PG  - 318-23
AB  - Additives that provide stress relief may be incorporated into dental composites 
      to reduce contraction stress (CS). This study attempted to test the hypothesis 
      that conventional fillers could be replaced by high-density polyethylene (HDPE) 
      spheres in hybrid and nanofill composites to reduce CS, but with minimal effect 
      on mechanical properties. Nanofill and hybrid composites were made from a 
      Bis-GMA/TEGDMA resin having either all silica nanofiller or 75 wt.% strontium 
      glass + 5 wt.% silica and replacing some of the nanofiller or the glass with 0%, 
      5% (hybrid only), 10% or 20 wt.% HDPE. The surface of the HDPE was either left 
      untreated or had a reactive gas surface treatment (RGST). Contraction stress (CS) 
      was monitored for 10 min in a tensilometer (n = 5) after light curing for 60 s at 
      390 mW/cm(2). Other specimens (n = 5) were light cured 40 s from two sides in a 
      light-curing unit and aged 1 d in water before testing fracture toughness 
      (K(Ic)), flexure strength (FS), and modulus (E). Results were analyzed by ANOVA 
      with Tukey's multiple comparison test at p < 0.05. There was no difference 
      between composites with RGST and untreated HDPE except for FS-10% HDPE hybrid 
      (RGST higher). An increased level of HDPE reduced contraction stress for both 
      types of composites. Flexure strength, modulus (hybrid only), and fracture 
      toughness were also reduced as the concentration of HDPE increased. SEM showed 
      evidence for HDPE debonding and plastic deformation during fracture of the hybrid 
      composites. In conclusion, the addition of HDPE spheres reduces contraction 
      stress in composites, either through stress relief or a reduction in elastic 
      modulus.
CI  - Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 
      66B: 318-323, 2003
FAU - Ferracane, J L
AU  - Ferracane JL
AD  - Department of Biomaterials and Biomechanics, Oregon Health & Science University, 
      School of Dentistry, 611 SW Campus Drive, Portland, Oregon 97239, USA. 
      ferracan@ohsu.edu
FAU - Ferracane, L L
AU  - Ferracane LL
FAU - Braga, R R
AU  - Braga RR
LA  - eng
GR  - DE07079/DE/NIDCR NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biomed Mater Res B Appl Biomater
JT  - Journal of biomedical materials research. Part B, Applied biomaterials
JID - 101234238
RN  - 0 (Composite Resins)
RN  - 9002-88-4 (Polyethylene)
SB  - IM
MH  - Biomechanical Phenomena
MH  - *Composite Resins
MH  - Humans
MH  - In Vitro Techniques
MH  - Materials Testing
MH  - Microscopy, Electron, Scanning
MH  - Microspheres
MH  - Particle Size
MH  - *Polyethylene
MH  - Surface Properties
EDAT- 2003/06/17 05:00
MHDA- 2003/08/28 05:00
CRDT- 2003/06/17 05:00
PHST- 2003/06/17 05:00 [pubmed]
PHST- 2003/08/28 05:00 [medline]
PHST- 2003/06/17 05:00 [entrez]
AID - 10.1002/jbm.b.10019 [doi]
PST - ppublish
SO  - J Biomed Mater Res B Appl Biomater. 2003 Jul 15;66(1):318-23. doi: 
      10.1002/jbm.b.10019.