Intra-radicular posts
Historically it was understood that the placement of an intra-
radicular post would reinforce the root and provide greater resist-
ance to root fracture. Clinical studies have not shown reduction in
fracture incidence by the placement of a post in pulpless teeth
10
; the
bulk of remaining tooth structure rather than the presence of a post
is important in providing resistance to fracture. The only exception
to this is when a tooth has a very large canal space with thin root
dentine walls at risk of fracture. Such a situation may typically arise
in an upper incisor that became non-vital at a young age (typically
due to trauma). The radicular dentine will be thin with a very large
pulp space. It is possible that bonding techniques may allow for
reinforcement for the root via placement of a low viscosity resin com-
posite into the root with a light-transmitting intra-radicular post to
allow for light-activated polymerisation of the resin composite to the
full depth
17
. Although evidence for this is limited at present, it would
seem to be a useful technique to reduce the potential for fracture of
such teeth.
From available evidence it would appear that the only true indica-
tion for post placement in a tooth is to retain a core, more specifically:
• To retain a restoration when a lack of coronal tooth structure
remains following root canal treatment. This lack of tooth structure
would not enable satisfactory resistance or retentive form for a
direct or indirect restoration without the placement of a post in
order to retain a core.
• There is insufficient crown tissue left on a vital tooth to accom-
modate placement of a core (to support a crown). In such cases
elective root treatment may be undertaken.
The term ‘post-crown’ is often used but perhaps ‘post-retained core’ is
more appropriate.
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