The Journal
Classification
Vertical root fractures (VRFs) are classified
either on the basis of separation of the
fragments (complete or incomplete) or on the
basis of relative position of fracture to the
alveolar crest (supraosseous and
intraosseous).
Complete fracture
When total separation is visible or fragments
can be moved independently.
Incomplete fracture
When there is an absence of visible separation
and segments can easily be
separated by an instrument.
Supraosseous fracture
This terminates above the bone, and does n ot
create a periodontal defect.
Intraosseous fracture
This involves the supporting bone, creating a
periodontal defect.
Aetiology
Restorative treatment
Extensively restored teeth,Large restorations,
forceful seating of crowns, intracoronal
restorations (inlays), and the placement of pins
can cause root fractures due to wedging action.
Mechanical weakening of the tooth structure
occurs during access cavity preparation,
whereas cleaning and shaping of root canals
increases the chances of tooth fracture.
Placement of a crown or pulp removal prevents
the local dentinal deformation, raising the
threshold of perception for loading. This
increases considerably the mechanical forces
applied to the pulpless tooth as compared to the
intact tooth.
\Root canal obturation and post placement (due
to wedging effects )can also lead to root
fractures, especially in the apical region.
Tapered and threaded posts generally produce
the highest root fracture incidence (7%),
followed by tapered and parallel posts.
Fractures with tapered posts occur at the
coronal-third of the root and, with parallel posts,
occur at the apical-third of the root.
Also, stresses from cementation of posts, due
to hydrostatic pressure of cement, are likely to
cause relative deformation of roots.
The volume of posts may expand in three-
dimensions, as a result of deposition of
corrosion products on their surface giving rise to
longitudinal root fracture.
Parafunctional habits
Repetitive excessive occlusal forces occurs in
posterior teeth, leading to ‘fatigue root fracture’.
Diagnosis of vertical root fractures
Endodontic treatment
A VRF in endodontically treated teeth may be
defined as a line in the longitudinal direction,
initiating at the internal root canal wall and
extending to the external root surface toward
the periodontal tissues. It occurs in any third of
the root canal and tends to split the root in the
buccolingual direction.
The incidence of root fracture increases as the
mesio-distal diameter of the root decreases
(maxillary second premolar, mesiobuccal roots
of maxillary molars, mesial roots of mandibular
molars).
10
3
1
15
4
Diagnosis is sometimes difficult as there is
often no single clinical feature which indicates
that root fracture is present.The characteristic
signs and symptoms may manifest in days or
years after the fracture (average of 3 days to 14
years). Other diagnostic difficulties of this type
of fracture are related to endodontically treated
teeth because the line of fracture may be
shadowed by the obturation material.
Vol. 13
12 No. 2
3
May-August
Sept-Dec 2016
May-August
2016
2017