1. 15Dentistry www.dentistry.co.uk 24 April 2014
clinical
It can be confusing attempting to identify
occlusal factors that may be contributing
to failure of the dentition, or that may
precipitate premature failure of restorative/
aesthetic dentistry if not corrected.
It is useful to consider the ideal
occlusion and how the dentition you
are assessing deviates from this. This
involves static and dynamic examination
of the teeth with the patient performing
functional movements of the mandible
and examining the teeth for possible
indicators of occlusal damage.
By doing so a risk assessment of
the likely stability of the dentition or
predictability of any restorative/aesthetic
treatment can be made.
If the occlusion is not ideal it may be of
no consequence as most patients function
satisfactorily with imperfect occlusions.
However, there is a difference between
accepting a less than ideal occlusion and
failing to identify it.
A few of the features of the ideal
occlusion that are particularly relevant to
restorative/aesthetic dentistry include:
• A stable and reproducible pathway
into the intercuspal position (ICP)
• Simultaneous and even cusp fossa
contact in ICP
- No vertical or horizontal slides
• Posterior disclusion on mandibular
protrusion
- Smooth guidance by the palatal
surfaces of the upper anterior teeth
• Canine guidance on lateral mandibular
movements
- Canines acting as ramps separating
and protecting the anterior and posterior
teeth
• A class I incisor relationship
- No excessive overbite
• Absence of cross bites.
Clinical example
The minimally restored UR1 and UR2
fractured extensively during eating and
were repaired with pinned composites
prior to referral for a specialist opinion
(Figures 1 and 2).
It was apparent that there was an
increased overbite and a lack of canine
guidance with the canines in cross bite.
Incisal and palatal tooth surface loss
(TSL) was noted on the upper incisor
teeth (Figures 3 and 4). TSL was noted
on the incisal edges and buccal aspect of
the lower incisor teeth (Figure 5).
The fracture of the teeth and TSL was
diagnosed as being due to excessive
occlusal forces due to a lack of protective
lateral guidance and the increased
overbite.
It was decided to restore the anterior
teeth with minimal all ceramic crowns,
but conforming to the existing occlusion
was not desirable as it may result in
premature restoration failure due to
possible cement overload, core/tooth
fracture or porcelain chipping/fracture.
Excessive wear of the lower incisor teeth
may result from attrition by the upper
ceramic crowns.
Comprehensive orthodontics was
recommended to correct the occlusion
and midline but the patient declined, so
short term orthodontics was undertaken
(Figures 6 and 7).
Post orthodontics a prep through guide
was constructed from the diagnostic
wax up (Figures 8 and 9) that rounded
out the arch form slightly and a small
anterior open bite was created during
the orthodontics, minimising tooth
Figure 1 Figure 2
Achievinglongtermpredictabilityin
aestheticandrestorativedentistry
Dominic Hassall presents a
multidisciplinary approach to correct
occlusal issues prior to aesthetic
restorative treatment
Dominic Hassall BDS MSc (Manc) FDS RCPS (Glasg) MRD RCS (Edin) FDS Rest
Dent (Eng).
Director of Dominic Hassall Training Institute and associate clinical professor
of restorative and aesthetic dentistry at the University of Warwick. President
of the British Academy Aesthetic Restorative and Implant Dentistry. He is a
GDC registered restorative, prosthodontic and periodontal specialist.
Figure 3
Figure 4
Figure 5 Figure 6
Figure 7
Figure 11
Figure 9
Figure 13
Figure 8
Figure 12
Figure 10
Figure 14
preparation with minimal buccal and
virtually no palatal reduction required
(Figure 10). The wax up formed the
basis for the provisional restorations
allowing assessment of aesthetics and
function prior to fabrication of the final
restorations (Figure 11).
All ceramic E.max crowns were
constructed with a palatal channel
accommodating bonded retention
(Figure 12 and 13). The final restorations
were fitted within eight months of the
commencement of treatment (Figure 14).
The patient was delighted with the
final result and the multidisciplinary
approach ensures long-term
predictability of the restorations as the
overbite was reduced and protective
lateral guidance provided. Permanent
retention provides long-term occlusal
stability (Figure 15).
Figure 15