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Class I. Caries affecting pits and fissures.
Class II. Caries affecting the approximal surfaces of
posterior teeth
Fig. 5.6 (a) A set of four titanium nitride instruments used for placing
and shaping composite. The surface of the instrument is very hard and is
not scratched by the composite filler particles. It also resists the composite
sticking to it. From the left: flat-plastic, carving instrument, burnisher,
plugger.
(b) Stainless steel plastic instruments. From the left: amalgam condenser,
burnisher, carving instrument (a half Hollenback), flat-plastic.
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Fig. 5.20 Composite finishing instruments.
Across the top is a plastic finishing strip with a
blank area in the middle to facilitate passage
between the teeth. On the right the abrasive is
coarse and on the left it is fine. From the left: a
mounted fine white stone, two medium-grit
composite finishing diamonds, two fine-grit
composite finishing diamonds, a mounted
abrasive rubber disc, a mandrel for the two
abrasive single-sided flexible discs which are
snap-fit onto the mandrel, and four
colour-coded flexible abrasive discs mounted on
plastic stubs which fit the mandrel to the right
of the picture.
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Fig. 8.12 (See also pp. 141 and 142) (a) Cavity prepared in a lower premolar for a posterior
composite restoration. Approximal caries and occlusal caries were removed. The occlusal caries
was found to be minimal and the cavity was not extended into dentine. Note the flaring of the
cavity towards the cervical margin.
(b) A thin, contoured, metal matrix in place. The wedge will encourage adaptation at the cervical
margin, but a probe should always be used to check that the band is tightly adapted.
(c) A spring steel ring is used to further stabilize the matrix and encourage tooth separation.
These can be applied using rubber dam forceps or a specially made instrument as shown here.
The yellow widget helps to keep the rubber dam in place mesially. Strips of the dam or floss
could
also achieve a similar result.
(d) Side view of matrix holder showing engagement of ring between teeth.
(e) The whole of the cavity is etched with phosphoric acid gel for 20 seconds.
(f) The acid gel is washed away.
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(g) Large amounts of water are blown away with an air syringe without drying the tooth. Any
remaining water is removed from the cavity using a cotton pledget or large endodontic paper
point.
(
Fig. 8.12 (continued)
(h) The bonding agent is applied (following
manufacturers directions).
(i) Gentle and complete solvent evaporation is
essential.
(j) The bonding agent is light-cured for
1020 seconds.
(k) The first portion of composite is placed.
(l) The composite is directed to the floor and one
wall of the proximal cavity.
(m) The restoration is cured through the tooth from
the same side. This helps to prevent polymerization
stress build-up. The second (and any other)
increments are then added and cured.
(n) The matrix is removed.
(o) The final increment of composite is contoured
as much as possible before it is polymerized. A
multi-bladed tungsten carbide finishing bur is used
to contour the marginal ridge (note the water
spray).
Fig. 8.12 (continued)
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(p) A rugby ball-shaped fine diamond is used to contour the occlusal anatomy. All high-speed
instruments must be used with water spray.
(q) A flexible, abrasive, impregnated disc is used to smooth the occlusal contours.
(r) The interdental area can be gently polished with suitable abrasive strips.
(s) To seal defective margins, which may show up after polishing, the tooth is re-etched for
15 seconds, washed, and dried as before.
(t) Bonding agent is liberally rubbed over the surface, then air-thinned and any solvent
evaporated. It is finally light-cured from all directions.
(u) The completed restoration before removing the rubber dam and checking the occlusion.
(v) Side view showing the rounded proximal contours achievable with soft metal matrices.
(s)
(t) (u)
(v)
(p)
(q) (r)