Download the problems of tooth surface loss

THE PROBLEMS OF
TOOTH SURFACE LOSS
A CASE HISTORY
BY MATTHEW CONDON
M
Matthew qualified from Sheffield Dental
School in 2010, and completed the
Diploma of Membership of the Joint
Dental Faculties of the Royal College of
Surgeons of England in 2012. He then
worked as a Senior House Officer in Oral
and Maxillofacial Surgery at Pinderfields
Hospital in Wakefield, and now works at
Farsley Dental Practice in Leeds, where
he has recently completed the FGDP
Diploma in Restorative Dentistry
anagement of tooth surface
loss (TSL) is a major issue
facing dentists – it has been
shown that 11% of adults
have moderate wear with
extensive dentine involvement, and 1% have
severe wear.1 TSL is often accompanied by
dento-alveolar compensation which ensures
the teeth still occlude, which is useful as it
allows continued function. However, this
means there is often insufficient occlusal space
to restore the teeth.
The Dahl concept was first described
nearly 40 years ago, using planned axial
tooth movements to aid restoration of worn
down anterior teeth. The technique is very
successful, with the literature reporting
success rates of 94-100%2 which does not
seem to be affected by the patient’s age or
sex. The occlusion is generally re-established
over an average of 6 months, but may take
up to 18-24 months.2 In the rare event that
the occlusion is not re-established, most
patients will tolerate the reduction in occlusal
contacts and no further treatment is necessary.
If the patient requires more occluding
teeth posteriorly, this can be achieved using
adhesive techniques.
The original removable cobalt chrome
‘Dahl appliance’ was unaesthetic and not
well tolerated and, therefore, is no longer
Fig.1: pre-operative frontal view smiling
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commonly used. More cases are now
being carried out using direct placement
composite at an increased occluso-vertical
dimension, placed using a stent constructed
from a diagnostic wax-up. If carried out
carefully this can have good aesthetics while
being minimally invasive. This is seen as a
medium-term option as the composite can
discolour and fracture, although this is less
likely if placed in sufficient thickness. This
case study describes a case that was treated
using this technique.
HISTORY AND EXAMINATION
This case history describes the treatment
of a 45-year old lady who attended for an
examination complaining of worn down and
discoloured teeth, and of multiple discoloured
filings. She reported that she thought that she
may be grinding her teeth at night time.
Medically, she was generally fit and well,
and used to smoke 20 cigarettes a day until
the age of 35 which may account for some of
the staining around the existing fillings.
On examination, no extra-oral
abnormalities were detected. There was some
mild marginal gingivitis and faint white
patches bilaterally on the buccal mucosae
along the occlusal lines, which had the
appearance of frictional keratosis.
There were multiple worn-down and
stained composite restorations in the
anterior teeth, as can be seen in the preoperative photographs. There was moderate
pathological non-carious tooth surface loss
which appeared to be due to attrition and
erosion, which was mainly affecting the
upper anterior teeth. A full assessment of the
tooth surface loss was made using the Smith
and Knight index.3 (Figs. 1,2 and 3)
The oral hygiene was generally good
– there was some supragingival calculus
evident around the lingual surfaces of the
lower anterior teeth, with some minimal soft
plaque deposits and minimal bleeding on
probing elsewhere in the mouth.
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The patient has a relatively high lip line,
with the gingival margins just visible when
smiling. There was around 1mm of upper
incisor visible at rest. The upper incisor teeth
were quite worn, and were 7mm in height
and 7mm in width, making them appear
short and square.
The patient was asked to complete a diet
sheet for 2 week days and 1 weekend day, in
order to assess whether she had a high intake
of acidic drinks which might be contributing
to the tooth surface loss.
Fig.2: pre-operative retracted frontal view
DIAGNOSES
The diagnoses were as follows:
• Mild plaque induced gingivitis in all
sextants, with calculus evident on lingual
surface of lower anterior teeth
• Bruxism – the patient was aware that she
was grinding her teeth during the night and
was not wearing any form of splint
• Frictional keratosis bilaterally on buccal
mucosae along occlusal line, likely due to
patient’s bruxism
• Moderate pathological non-carious tooth
surface loss predominantly affecting the
upper anterior teeth, which appears to be
due to attrition from bruxism and erosion
from an acidic diet.
• Worn and discoloured composite
restorations with poor margins in UR3 UR2
UR1 UL1 UL2 UL3 LR5 LR4 LR3 LR2
LR1 LL1 LL2 LL2 LL4 LL5, also general
yellow discolouration of teeth
It is important with TSL cases to ensure
that the causes have been identified and
addressed. The patient was advised to
minimise her intake of acidic foods and
drinks in order to minimise further erosion
and a soft splint was to be made after the
occlusion becomes re-established in order to
protect from damage from bruxism.
TREATMENT OPTIONS
Porcelain veneers
The advantage of porcelain veneers is that
they provide improved aesthetics and a
natural appearance, and have good colour
stability when compared to composite.4 The
disadvantage of veneers is the biological cost
due to the preparation required, and the
increased financial cost for the patient.
FULL COVERAGE CROWNS
We also discussed crowning these teeth, but
these restorations would now be seen as quite
an aggressive treatment option here. Around
19% of crowned teeth show evidence of periradicular disease,5 showing that the crowning
of teeth often leads to pulpal and periapical
disease. A study by Smales et al6 compared
direct and indirect restorations provided for
the treatment of anterior tooth wear. They
showed that where crowns are used to treat
tooth wear, when they fracture it is more likely
to involve the underlying tooth, and the teeth
are more likely to need root canal treatment or
extraction when the failure occurs.
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Fig.3: pre-operative upper occlusal view
DIRECT PLACEMENT COMPOSITE
We also discussed the option of using
direct placement composite, using a stent
constructed from a diagnostic wax-up. A
study by Gulamali et al7 showed a median
survival rate for composite restorations of 5.8
years when used to treat anterior tooth wear.
When these restorations fail, it is typically due
to wear, discolouration or fracture that doesn’t
involve the underlying tooth. Therefore,
when they do fail, in most instances, they
can simply be polished or repaired. They can
be placed without preparing the tooth, and
therefore have the lowest biological cost of the
options discussed here, and also the financial
cost involved is lower. It is difficult to achieve
the same aesthetic result as with veneers or
crowns, but if care is taken during placement,
good aesthetic results can be achieved.
CONFORM OR RE-ORGANISE?
In order to improve the aesthetics by
restoring the upper anterior teeth to
the desired morphology, an increase in
occluso-vertical dimension would be
required. Therefore the conformative
approach could not be used, and a reorganised approach is indicated.10
The wear in this case was mainly affecting
the upper anterior teeth. The posterior teeth
were largely unaffected – they had sustained
little if any tooth surface loss compared to
the anterior teeth, and therefore treatment
was not currently indicated for these teeth.
We discussed using the Dahl technique. The
benefit is that the worn anterior teeth are
restored and the occlusion should then reestablish, without the need to also restore the
posterior teeth.
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WHITENING
Whitening was carried out prior to the
new restorations. It is advised to wait at
least 2 weeks before bonding the composite
restorations to allow the shade to stabilise
and for the enamel structure to return to
normal, allowing the bond strength between
the enamel and composite to improve.8
DESIGN STAGE
When considering a re-organisation of an
occlusion, the first step is to examine the
patient’s existing occlusion.9 The patient had
a class 1 skeletal base, with a class 1 incisor
relationship. There was canine guidance on
left lateral excursion and group function on
right lateral excursion, with no working side
or non-working side interferences.
In order to deprogramme the jaws and
find centric relation, a tongue spatula was
used as described by Davies.10 The patient
was asked to slide into lateral and protrusive
excursions on this, sliding further back each
time she did this. She relaxed back into
centric relation quite quickly, and the initial
contact in centric relation was between the
UR6 and LR6, which was repeated to ensure
the same result was found each time.
The next stage is the design stage. The
technician mounted study models using a
facebow and the centric relation provided
and then constructed the wax-up of the
upper 3-3 to idealise the occlusion. The lab
then constructed a clear silicone stent using
Memosil (Heraeus Kulzer). (Figs. 4,5,6,7)
This can then be used to transfer the
design into the mouth, as described by
Ammanato et al.11 This is as an alternative
to using putty palatal indices to first build
up the palatal surface, then building up the
buccal surface by hand. While generally
easier to carry out, the downside to the clear
silicone stent technique is that only one
shade of composite can be used for each
restoration. The advantage of this is that it
copies the morphology of the wax-up more
accurately, rather than trying to recreate the
shape manually.
Rather than proceed straight to placing
the restorations, an intra-oral ‘mock-up’ was
carried out. Luxatemp material was placed
into the stent, which was then seated in the
mouth and cured. This then gave the patient
an idea of what the final result will look like.
Although this takes an extra appointment
and is therefore more time consuming, the
patient then has the opportunity to suggest
any changes that may be more difficult to
make after the definitive restorations have
been placed.
PLACEMENT OF COMPOSITES
The Optident Dentoprep mini sandblaster
was used prior to bonding the composite
restorations, as this has been shown to
increase the bond strength between enamel
and composite resin.12,13 PTFE tape was
used in between the teeth to avoid bonding
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THIS PHOTO: Fig.6: Diagnostic
wax-up, occlusal view; ABOVE
LEFT: Fig.4: Completed Denar
Facebow record; ABOVE RIGHT:
Fig.5: Diagnostic wax-up,
frontal view; BELOW: Fig.7:
Clear silicone stent
the restoration to the adjacent teeth.
Heated Filtek-supreme composite was then
syringed into the Memosil stent, and then
fully seated in the mouth. This was lightcured through the translucent Memosil
stent, and the matrix was removed. Any
excess interproximally was removed using
V-saw strips and interproximal strips,
then the restorations were polished using
Shofu rainbow discs and white stones. The
occlusion was then checked and adjusted,
ensuring that this correctly matched the
prescription from the diagnostic wax-up.
(Figs. 8,9,10 and 11)
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Fig.8 : Lower teeth after removal of
previous composite restorations
Fig.9 : Lower teeth after placement of new
composite restorations after initial shaping
Fig.10 : UR1 isolated using PTFE tape after
removal of previous composite restoration
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Fig.11: UR1 and UL1 after placement of new
composite restorations after initial shaping
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OUTCOMES
At the 6-month review, the posterior
occlusion had re-established, there were no
fractures to the restorations and the patient
was functioning well. As posterior contacts
had been re-established, a lower soft splint
was made to protect from further damage
from her bruxism. She was happy with the
improved aesthetic appearance of the teeth,
and reported that her husband and family are
also happy with the result. (Figs.12,13 and 14)
The major advantage of this technique
when compared to conventional
prosthodontic techniques is that it is
purely additive apart from removing the
old composite restorations and therefore
has a lower biological cost. The composite
restorations may wear and chip over time
but, if the restorations fail it is not likely
to involve the underlying tooth and so the
restoration can often be simply replaced.
The wax-up and stent can be kept and used
to repair and replace the restorations as and
when this becomes necessary.
Prior to the FGDP Restorative Diploma,
I would not have undertaken this case, but
with the clinical teaching and treatment
planning sessions, treating cases similar to this
becomes relatively routine and predictable.
When planned properly, the treatment itself is
generally simple, and can easily be carried out
in a general practice setting.
Fig.12: Retracted frontal view showing new
composite restorations at 6 month review
THIS PHOTO: Fig.13: Frontal smiling view showing
new composite restorations at 6 month review;
LEFT: Fig.14: Upper occlusal view at 6 month review
showing re-established posterior occlusal contacts
REFERENCES
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1998. London: The Stationery Office
2. 2. Poyser NJ, Porter RW, Briggs PF, Chana HS, Kelleher MG. The Dahl Concept: past, present and future. Br Dent J. 2005
11;198(11):669-76
3. Smith B, Knight J. An index for measuring the wear of teeth. Br Dent J 1984; 156:435–438
4. Ittipuriphat I, Leevailoj C. Anterior space management: interdisciplinary concepts. J Esthet Restor Dent. 2013;25(1):16-30
5. Randlow K, Glanz PO. On cantilever loading of vital and non-vital teeth: an experimental clinical study. Acta Odontol Scand
1986; 44:271-277
6. Smales RJ, Berekally TL. Long-term survival of direct and indirect restorations placed for the treatment of advanced tooth wear. Eur
J Prosthodont Restor Dent. 2007 Mar;15(1):2-6.
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anterior tooth wear (ten-year follow-up). Br Dent J. 2011 Aug 26;211(4)
8. Sulieman M. An overview of bleaching techniques: 2. Night guard vital bleaching and non-vital bleaching. Dent Update.
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9. Davies SJ, Gray RM, Whitehead SA. Good occlusal practice in advanced restorative dentistry. Br Dent J. 2001 27;191(8):421-4,
427-30, 433-4
10. Davies SJ. Conformative, re-organized or unorganized? Dent Update. 2004;31(6) 334-6, 338-40, 342-5
11. Ammannato R, Ferraris F, Marchesi G. The “index technique” in worn dentition: a new and conservative approach. Int J Esthet
Dent. 2015;10(1):68-99
12. Zhang HP1, Wei Y, Deng XL, Zheng G. The effect of simulate intraoral sandblasting on the bond strength between enamel and
composite resin. Beijing Da Xue Xue Bao. 2004;36(2):207-9
13. Sohrabi A1, Amini M, Afzali BM, Ghasemi A, Sohrabi A et al. Microtensile bond strength of self-etch adhesives in different
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