Page 29 - COS-FOD2015

NZarina et al.

Impression making and evaluation of sur- impressions were recorded using a high resolu-
face detail reproduction tion 3D optical scanner (InfiniteFocus, Alicona
Imaging GmbH, Austria). A master die was
Each master die was left at room temperature
placed on motorized stage with magnification
(23±1)°C for 7 days before immersing in dis-
and vertical resolution selected at 5x and 60μm
tilled water at (37±1)°C for 5 minutes to pro-
respectively. The coaxial white light was deliv-
duce a moist die stone for the impression mak-
ered through a ring light. The start and end po-
making. A pilot study revealed that the optimum sitions on the master die was determined by
duration for Velmix die stone of 40 mm in diam- moving the cursor at a horizontal plane be-
eter and 21 mm thick to be fully saturated with tween the two reference points. A preliminary
water is 5 minutes. Impression making proce- scan (Figure 2) which was carried out to deter-
dures for all tested materials were as described mine the highest and lowest points at each ref-
in the master die preparation stage. All medium erence point; L1, L2 and L3. The entire 3D im-
- and light-bodied impression materials were age which constitute the depths of grooves
syringed using auto-mixing impression dis- were then stitched and measurements were
penser except for Impregum Penta and Im- then obtained using the software, Alicona Ver-
pregum Penta H Duosoft which was dispensed sion 2.1.5 Generation 4, 2008. The same pro-
using a mechanical dispenser (Pentamix 2, 3M cedure was repeated for the impression. Both
ESPE, St Paul,USA). master die and impression were illustrated in
3D true colour and pseudocolour (Figure 3).
The topography of all the master dies and its

Figure 3: Illustration of 3D image of master die with true colour and pseudocolour images
(a,b) and 2D measurement of master die’s grooves (V 1,V 2,U 1 and U 2)

Illustration of 3D image Express™ XT Light Body and Putty Soft with true colour and

pseudocolour images (c,d) and 2D measurement of Express™ XT Light Body and Putty Soft
Grooves (V 1,V 2,U 1 and U 2)

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