Endodontics Continued »
Frequently, they present with peri- apical lesions, which may or may not be associated with apical resorption. Short roots compromise the crown- root ratio, often affecting long-term prognosis. Fractures of the crown are
common following trauma. This can compromise aesthetics, especially in the anterior region and there may be a lack of tooth tissue present. In long standing cases, these teeth may also undergo discolouration. Large open apices pose a challenge in determining the working length, decision on the necessity of root canal preparation, and achieving control during obturation.
How is the working length determined? There is relatively little data regarding the value of radiog- raphy and electronic apex locator (EAL) use when root formation is incomplete, and supplementary measurement techniques may be helpful. When using an EAL to measure working length in such cases, it is essential to use a file which is well matched to the apical size (see Fig 2) where possible. The paper point technique described by Rosenberg to supplement initial apex locator readings could be considered for the working length determination of open apices in relatively straight canals5 Marcos-Arenal et al,6
. in an in
vivo study, demonstrated an 87 per cent accuracy of this technique in establishing working length to within 0.5mm of the apical foramen. El Ayouti et al,7
proposed a tactile
No Barrier Placement
Customised Cone
Short Fill Obturation
Thermoplasticised Techniques
Apexification 1. Ca(OH)2 2. MTA 3. Others
Barrier Placement Fig 3
Apexogenesis 1. Antibiotic tripaste 2. Others
Fig 4e Ireland’s Dental magazine 31
ABOUT THE AUTHORS
Robert Smyth, BDS, MFDS RCPSG, MFDS RCSEd, graduated from QUB in 2012.
Below: Series of radiographs showing MTA plug, thermoplas- ticised gutta percha and coronal restoration
Fig 2
Working length radiograph of maxil- lary anterior teeth with open apices (note large file sizes and irregular anatomy of apices)
method involving the use of a size 25 K-file bent at the tip, with its orienta- tion marked with a silicone ring. The file was bent to facilitate ease of use. In this study, 95 per cent of cases were accurate to within 0.5mm of the apical foramen.
Do I need to instrument the canal? During conventional root canal treatment, the role of instrumenta- tion is to achieve removal of vital and necrotic tissues from the root canal system, along with infected root dentine8
. It aims to prepare the
canal space to facilitate attempts at disinfection using irrigants and medicaments. As a result, minimal instrumentation of teeth with open apices (and thin dentinal walls) is needed due to the ease in placement of irrigation devices close to the working length.
Continued » Fig 4d
Following two years working in general practice in Ballyclare and Cookstown, Northern Ireland, he took up a core training job at the Edinburgh Dental Institute.
Bob Philpott, BDS, MFDS RCSI & RCSEng, MClinDent (UCL), MRD RCSEd,
Fig 4a
graduated with a BDS from Cork and undertook his specialist training in endo at the Eastman in London.
He now works as a senior clinical lecturer/ honorary consultant at Edinburgh Dental Institute and will
commence private
practice at Edinburgh Dental
Specialists in February 2015.
Fig 4b Fig 4c
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