Introduction . Recently, composites contaning monomers alternative to conventional dimetacrylates appeared on the market. According to the manufacturers, these new composites show lower volumetric shrinkage, which would lead to lower polymerization stress at the tooth/restoration interface.

Objectives . to evaluate the volumetric shrinkage and the polymerization stress (at two compliance levels) of composites with different organic matrix compositions.

Materials and methods . Nine commercial composites were tested. Seven were based on Bis-GMA (Durafill/Kulzer, Filtek Z250/3 M ESPE, Heliomolar/Ivoclar, Aelite LS/Bisco, Point 4/Kerr, Filtek Supreme/3 M ESPE, Extra Low Shrinkage/Saremco); one was silorane-based (Filtek LS/3 M ESPE); and one was based on a dimer acid dimetacrylate (N’Durance/Septodont). Volumetric shrinkage was measured using a mercury dilatometer ( n = 3). Polymerization stress was obtained by inserting composite between glass or PMMA rods ( = 5 mm, n = 5). Data were submitted to one-way ANOVA/Tukey test ( α = 0.05).

Results

Table. Means (SD) of polymerization stress (MPa) after five minutes for both substrates, and volumetric shrinkage (%) after 5 min. In the same column values with the same letter are not statistically different ( p > 0.05).

Composite	Polymerization stress (MPa)		Volumetric shrinkage (%)
	Glass	PMMA
ELS	2.6 (0.4) C	2.7 (0.3) c	2.20 (0.08) BC
Durafill	3.4 (0.3) C	2.6 (0.2) d	2.01 (0.03) D
Heliomolar	5.4 (0.5) B	2.8 (0.4) c	1.72 (0.03) E
Filtek Supreme	5.8 (0.6) B	4.2 (0.4) a	2.10 (0.03) CD
Aelite LS	6.2 (0.7) AB	3.4 (0.2) b	2.04 (0.13) CD
Filtek Z250	6.2 (0.8) AB	3.3 (0.2) bc	1.82 (0.07) E
N’Durance	6.7 (0.7) AB	3.9 (0.2) ab	2.29 (0.03) B
Point 4	–	4.3 (0.4) a	3.20 (0.02) A
Filtek LS	7.4 (0.9) A	4.3 (0.3) a	1.40 (0.02) F

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related

Related posts:

1. Abstracts from the Academy of Dental Materials conference in Portland, October 2009. Poster Index by presenter
2. Effect of instrument compliance on polymerization shrinkage stress measurements of composites
3. Testing bond strength: A review of the literature
4. Compatibility of self-etching dentin adhesives with resin luting cements
5. Effect of particle deposition protocols on flexural strength of zirconia after cyclic loading
6. A novel experimental method for the local mechanical testing of human coronal dentin

Stay updated, free dental videos. Join our Telegram channel

Join