245 Physical Properties of Newer Glass-Ionomer Restorative Materials

Thursday, March 22, 2012: 2 p.m. - 3:15 p.m.
Presentation Type: Poster Session
A.J. STOY1, W. LIEN1, K. VANDEWALLE1, S. SPECK1, and K. SABEY2, 1USAF, Lackland AFB, TX, 2LSU, New Orleans, LA
A new resin-modified glass-ionomer (RMGI) restorative material (Ketac Nano Quick Mix, 3M/ESPE) with nano-technology has been recently introduced in a quick-mix capsule system that does not require trituration.  Objectives: To compare the physical properties of various RMGI and conventional glass-ionomer restorative materials: Ketac Nano Quick Mix (3M/ESPE), Ketac Nano Paste-Paste (3M/ESPE), Fuji II LC (GC), Fuji Filling LC (GC), and Ketac Fill (GC).  Methods: Compressive strength, flexural strength/modulus, fracture toughness, and percent porosity were examined.  Ten specimens were fabricated per group.  For compressive strength testing, cylindrical specimens were prepared in a 6-mm thick x 4-mm diameter stainless-steel mold, light cured all sides (Bluephase 16i, Ivoclar) for 20-seconds each, stored 24-hours at 37oC / 95% humidity, and loaded to failure in a universal testing machine (MTS).  For flexural strength/modulus and fracture toughness testing, rectangular beam and single-edge notched specimens were created in a 2x2x25mm mold (1-mm preformed notch – fracture toughness), light cured in five over-lapping segments per side, stored as before, and tested in 3-point flexure.  Flexural modulus was determined from the slope of the linear region of the load-deflection curve.  For percent porosity of closed pores, specimens were created in a 2-mm thick x 8-mm diameter stainless-steel mold, scanned with a microtomographic unit (Skyscan 1172) and analyzed with software (CT Analyzer, Skyscan).  A mean and standard deviation were determined per group.  See table below.  A 1-way ANOVA/Tukey was performed per property (alpha=0.05).  Results: Except for percent porosity, significant differences were found between groups per property (p<0.001).  Conclusions: Compared to the other glass-ionomer restorative materials, the new quick-mix capsule Ketac Nano Quick Mix had high strength properties and low flexural modulus with no significant increase in porosity.

Restorative Material


Physical Property

Mean (std dev)


Glass Ionomer (Shade A-2)

Compressive Strength


Flexural Strength


Flexural Modulus


Fracture Toughness

(MPa m1/2)

Percent Porosity

Ketac Nano Quick-Mix

(RMGI, encapsulated)

96.06 (8.57) a

114.90 (17.50) a

8.54 (0.69) c

0.41 (0.09) ab

0.12 (0.07) a

Ketac Nano Paste-Paste

(RMGI, hand mixed)

84.77 (22.13) ab

108.72 (7.53) a

8.43 (1.04) c

0.30 (0.05) c

0.08 (0.05) a

Fuji 2 LC

(RMGI, encapsulated)

97.14 (10.01) a

68.80 (10.40) b

11.62 (1.25) b

0.48 (0.08) a

0.08 (0.03) a

Fuji Filling LC

(RMGI, hand mixed)

69.40 (5.11) bc

55.42 (6.89) b

9.14 (0.83) c

0.33 (0.05) bc

0.07 (0.06) a

Ketac Fill

(GI, encapsulated)

54.50 (12.37) c

33.16 (8.11) c

17.46 (2.10) a

0.17 (0.03) d

0.10 (0.07) a

Groups with the same letter per column are not significantly different (p>0.05)

Keywords: Dental materials, Glass ionomers and Physical