Langzeitliche Untersuchung der Veränderungen mechanischer Eigenschaften traditioneller und innovativer Glasionomerzemente unter labor- und klinisch simulierten Bedingungen

Objective: the study focused on a recently launched conventional
glass ionomer cement (GIC) with a particular chemical formulation
of both, filler and acrylic liquid, by analysing its mechanical
behaviour in comparison to three conventional GICs. Furthermore,
the effect of resin coating and storage conditions was evaluated.
Materials and methods: Three commercially available GICs were
chosen: Riva Self Cure (SDI), Fuji IX Fast (GC) and Fuji IX GP
Extra/Equia (GC). Additionally a new developed zinc containing GIC
- ChemFil Rock (Dentsply) - was tested. Mechanical properties were
determined at macro- {flexural strength (FS) and modulus of
elasticity (Eflexural)} and micro-scale {Vickers hardness (VH) and
indentation modulus (E)} after storing coated and uncoated
specimens in artificial saliva and distilled water for 7 and 30
days. Results: ChemFil Rock revealed the highest FS, but the lowest
VH and E. The micro-mechanical properties of the analysed GICs did
neither benefit from the new zinc formulation, nor from resin
coating. A resin coating is nevertheless a valuable support for GIC
fillings, since it offers the absence of visible surface defects
like crazing and voids and thus it led to significant improvements
in flexural strength. This statement is also valid for Chemfil
Rock, contrary to manufacture recommendation. The impact of storage
agent and storage duration on the measured properties was low.
Conclusions: The new development (ChemFil Rock) might represent a
promising approach regarding longevity of GIC fillings in molar
regions, due to the high flexural strength and the absence of
visible surface defects like crazing and voids. Clinical Relevance:
All GICs should receive surface protection in order to perform
their maximum in stability