: Stéphane Simon, Wilhelm-J. Pertot
: Clinical Success in Endodontic Retreatment
: Quintessence Publishing Co Inc USA
: 9782912550866
: 1
: CHF 82.50
:
: Zahnheilkunde
: English
: 89
: DRM
: PC/MAC/eReader/Tablet
: ePUB
Endodontic retreatment is technically more difficult to perform, involves greater risks, and is more unpredictable clinically compared with primary endodontic treatment. This book addresses topics such as indications for endodontic retreatment; safe and efficient removal of existing restorations and obturation material; challenges such as fractured instruments, hard pastes, blockages, and negotiation of the canal; treatment of perforations; management of a tooth with a wide-open apex; and assessment of prognosis and success. Well-illustrated with clinical photographs, radiographs, and diagrams, the book will enable practitioners to undertake endodontic retreatment with greater confidence.

Endodontic treatment should fulfill a variety of objectives (Schilder, 1967 and 1974):

• Create a continuously tapering preparation from the crown to the apices

• Maintain the position of the apical foramen on the root surface

• Maintain the shape of the original canal as much as possible

• Keep the apical foramen as small as possible

• Use copious irrigation to ensure the root canal system is thoroughly cleaned and disinfected

• Obturate and seal the root canal system.

Although the procedures for endodontic treatment of a vital or necrotic pulp were first described decades ago, the number of unsatisfactory endodontic results remains rather high. Epidemiologic studies published over the past 20 years show that the number of inadequate treatments varies between 60% and 79%, with a failure rate (that is, cases where clinical symptoms or periapical lesions exist) of 22 % to 63 % (Boucher et al, 2002).

Endodontic retreatment can be defined as further treatment performed because the initial treatment was inadequate or the lesion failed to heal.

From a clinical standpoint, the four causes of failure are inherent within each stage of endodontic treatment (Ruddle, 2004) :

• Inadequate access cavity due to failure to appreciate the anatomy of the tooth; this hampers visibility, which in turn results in the following:

– Failure to detect accessory canals

– Difficulty in correctly preparing the canal because of instruments further restricting visibility or difficulty in visualizing the entire canal system

– Perforations in the coronal third of the tooth or in the pulp chamber floor

• Insufficient irrigation during canal preparation

• Improper use of instruments during preparation, which may result in the following:

– Alteration of the canal trajectory, which can cause obstructions and eventual perforations

– Blockages and subsequent loss of working length (obstruction by debris or a fractured instrument); this prevents irrigation of the whole root canal system

– Widening of the apical foramen, making controlled obturation impossible

• An error in fitting the gutta-percha cone, resulting in moisture contamination, a fault frequently associated with inadequate preparation of the apex; however, obturation material extruded through the apex is not in itself an indication for either orthograde or retrograde retreatment.

Fro