IADR Abstract Archives

Evaluation of the Volumetric Shrinkage of a Novel Resin-Based Restorative

 

Objectives: Reduced polymerisation shrinkage and an associated increase in synergy between the tooth/restoration interface may be realised if novel monomer systems are developed which do not employ dimethacrylate monomers. Method: The mean bi-axial flexure strengths (BFS) and Weibull moduli (m) of an experimental oxirane RBC, EXL 580 and two commercially successful dimethacrylate RBCs were investigated. Volumetric shrinkage and degree of conversion were recorded using a gas pycnometer and FTIR analysis for 0.1, 0.5, 1, 4, 24 and 48h immersion in a waterbath maintained at 37±1°C, respectively. Results: A significant decrease in the BFS and associated elastic moduli of EXL 580 was observed after 0.1, 0.5 and 1h compared with Z250 and Z100. EXL 580 provided significantly less polymerisation shrinkage after each period of immersion.

Material

Z250

Z100

EXL 580

Immersion (h)

0.1

0.5

1

4

24

48

0.1

0.5

1

4

24

48

0.1

0.5

1

4

24

48

BFS (MPa)

130 (18)

143 (15)

157 (18)

144 (10)

140 (12)

134 (13)

133 (20)

141 (23)

141 (19)

144 (11)

126 (13)

134 (16)

65  (10)

107 (16)

145 (20)

160 (11)

168 (11)

150 (16)

m

7.53 (1.68)

10.2 (2.28)

8.90 (1.99)

10.95 (2.45)

11.87 (2.65)

10.85 (2.43)

6.59 (1.47)

7.66 (1.71)

8.99 (2.01)

9.46 (2.12)

10.19 (2.28)

9.19 (2.05)

4.68 (1.05)

5.79 (1.29)

7.37 (1.65)

8.06 (1.80)

16.2 (3.62)

9.78 (2.19)

Shrinkage (%)

1.94 (0.15)

1.95 (0.09)

1.98 (0.12)

1.89 (0.18)

2.01 (0.10)

1.96 (0.11)

2.18 (0.15)

2.27 (0.16)

2.13 (0.17)

2.19 (0.09)

2.14 (0.11)

2.15 (0.13)

1.08 (0.10)

1.11 (0.08)

1.09 (0.04)

1.01 (0.06)

0.91 (0.05)

0.93 (0.07)

Conclusions: Consequently, the improved mechanical and physical properties of the oxirane-based composite investigated in the current study may ultimately increase marginal integrity of such a restoration compared with dimethacrylate based systems. This work was co-funded by 3M ESPE and EPSRC Case Award 00303435.


IADR/AADR/CADR General Session
2002 IADR/AADR/CADR General Session (San Diego, California)
San Diego, California
2002
59
Dental Materials: VI - Polymer Materials-Mechanical Properties and Degradation
  • Palin, Will  ( University of Birmingham, Birmingham, N/A, United Kingdom )
  • Fleming, Gjp  ( University of Birmingham, Birmingham, N/A, United Kingdom )
  • Burke, Fjt  ( University of Birmingham, Birmingham, N/A, United Kingdom )
  • Marquis, Pm  ( University of Birmingham, Birmingham, N/A, United Kingdom )
  • Randall, R C  ( 3MESPE Dental Products, Minneapolis, N/A, USA )
    • Oral Session
    Low-viscosity Monomers/Nanocomposites
    03/06/2002