Philips Sonicare FlexCare - Sonicare.com - Sonicare

tively, representing typical clinical use, 4,24 and 150 g
for each brush used as a common reference point.
The 4 materials were Solidex c composite, EsthetX d
composite, 6AL-4V surgical-grade titanium, and
bovine enamel, which served as the control for the
composites.
Eight samples, each measuring 5 mm × 10 mm,
were prepared for each of the 4 treatments. Solidex
and EsthetX samples were constructed according to
each manufacturer’s recommendations. Enamel samples
from adult bovine incisors were cut using a dental
handpiece and a diamond-coated separating disk.
Each sample was placed into an acrylic mount measuring
20 mm × 20 mm. To simulate tooth curvature
at interproximal spaces, grooves measuring approximately
2 mm deep were placed parallel with a dental
handpiece on either side of the material samples for
the length of the acrylic mount. The acrylic mounts
and the embedded composite, titanium, and enamel
samples were then meticulously ground under water
with a surface grinder resulting in uniformly polished
surfaces. Finally, the top surface of each sample
was hand polished to a high shine using a water
slurry of 0.3 µm Alpha Alumina e and finishing with
0.05 µm Alpha Alumina on a cotton cloth.
Specimens were randomly assigned to the 4 treatment
groups.
Brushing was simulated by positioning the specimens
on a V-8 mechanical cross-brushing machine 25
equipped with either the manual or the FlexCare
power toothbrush. The power toothbrush handles
were externally powered so that they would operate
continuously at their normal setting during the complete
brushing period without recharging. Specimens
c
Shofu Dental Corp; San Marcos, CA.
d
Dentsply Caulk; York, PA.
e
Micropolish, Beuhler; Lake Bluff, IL.
were mounted below the toothbrush heads so the
specimens were level with the toothbrush filament
tip plane (defined by a plane between the tips of the
filaments on the proximal and distal tufts). The midpoint
of the stroke was aligned with the midpoint of
the specimen to ensure even brushing conditions
over the width of the specimen. Brushing force was
controlled before the experiment. All specimens
were assessed after 3,000 and 12,000 brushing
strokes, representing 6 months and 2 years of brushing,
respectively. 4 The brushing was done with a slurry
consisting of 1 part (by mass) toothpaste (Crest
Cavity Protection Cool Mint Gel b ) to 2 parts (by
mass) artificial saliva. Brush heads were immersed in
the slurry using plastic tubes filled with the slurry
placed around the free end of the brush head and
specimen. Spoon-like attachments secured to the
brush handles kept the slurry in suspension. Brushes
and brush heads were replaced for each trial so that
a new brush was used with each specimen.
Specimens were analyzed for abrasion by measuring
both surface gloss and roughness induced by
the different loads and brushes at baseline and 3,000
and 12,000 strokes. Gloss measurements were made
with a Rhopoint Novo-Curve Glossmeter f . The
mounted specimens were inverted on the
Glossmeter platform parallel to and covering the 4-
mm × 10-mm opening. Readings were taken at an
operating angle of 60 degrees over the area covered
by the aperture on top of the instrument. All readings
are given in gloss units (GU) as specified in
American Society for Testing and Materials (ASTM
D523). 26 As a general rule, readings fall between zero
(no reflectance) and 100 (highly reflective) for nonmetallic
surfaces. The calibration standard registers
f
Rhopoint Instrumentation Ltd; Bexhill-on-Sea, UK.
Ra
(µm)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Solidex EsthetX Enamel Titanium
FlexCare - 100 g
Manual - 250 g
Baseline
3,000
12,000
Baseline
3,000
12,000
Baseline
3,000
12,000
Baseline
3,000
12,000
Material and number of strokes
Figure 2—Change in surface roughness per material from baseline to 3,000 and 12,000 strokes for each treatment under clinical load conditions
44 Compendium / September 2007 Vol. 28, No. 9 (Suppl 1)