Restor Dent Endod.  2013 May;38(2):59-64. 10.5395/rde.2013.38.2.59.

Does apical root resection in endodontic microsurgery jeopardize the prosthodontic prognosis?

• Cho SY
• Kim E

• KMID: 1995460
• DOI: http://doi.org/10.5395/rde.2013.38.2.59

Abstract

Apical surgery cuts off the apical root and the crown-to-root ratio becomes unfavorable. Crown-to-root ratio has been applied to periodontally compromised teeth. Apical root resection is a different matter from periodontal bone loss. The purpose of this paper is to review the validity of crown-to-root ratio in the apically resected teeth. Most roots have conical shape and the root surface area of coronal part is wider than apical part of the same length. Therefore loss of alveolar bone support from apical resection is much less than its linear length.The maximum stress from mastication concentrates on the cervical area and the minimum stress was found on the apical 1/3 area. Therefore apical root resection is not so harmful as periodontal bone loss. Osteotomy for apical resection reduces longitudinal width of the buccal bone and increases the risk of endo-perio communication which leads to failure. Endodontic microsurgery is able to realize 0 degree or shallow bevel and precise length of root resection, and minimize the longitudinal width of osteotomy. The crown-to-root ratio is not valid in evaluating the prosthodontic prognosis of the apically resected teeth. Accurate execution of endodontic microsurgery to preserve the buccal bone is essential to avoid endo-perio communication.

Keyword

Ante's law; Endodontic microsurgery; Prosthodontic prognosis; Stress distribution

MeSH Terms

Alveolar Bone Loss
Mastication
Microsurgery
Osteotomy
Prognosis
Prosthodontics
Tooth

Figure

• 

  Figure 1 Pre-operative radiographs of 4 cases in which crown-to-root ratios were expected to be poor after apical surgery. (a) The patient was referred from a local clinic for apical surgery of tooth #11 due to failure of negotiation in 2008. The tooth had a history of trauma in 2000 and showed 4 to 6 mm apical root resorption; (b) Non-surgical root canal treatment of #21 was incompletely finished due to canal calcification. Two months later sinus tract recurred and the tooth was planned to take apical surgery. The apical root was shortened due to inflammation; (c) The patient was referred from the department of pediatric dentistry for increased apical lesion of tooth #12. The tooth had a history of intrusive luxation in 2000 and received non-surgical root canal treatment in 2001. Apical root resorption with apical lesion was observed and lateral perforation was suspected; (d) The patient was referred from a local clinic for proper treatment of tooth #12 in 2002. Horizontal root fracture was seen and apical surgery with removal of the fractured apical root was planned.

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  Figure 2 6-year follow up case of horizontal root fracture. (a) Horizontal root fractures were found on teeth #11 and #21 at the first visit in 2006; (b) The tooth #11 became necrotic and received non-surgical root canal therapy in 2007; (c) 3-year follow up radiograph in 2009; (d) 6-year follow up radiograph in 2012.

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  Figure 3 8-year follow up case of apical root resorption due to orthodontic treatment. (a) Radiograph before orthodontic treatment in 2004; (b) Radiograph just after orthodontic treatment in 2006; (c) 5-year follow up radiograph; (d) 8-year follow up radiograph.

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  Figure 4 Failure case due to endo-perio communication. (a) Pre-operative radiograph showing apical lesion of mesial root and furcation bone loss on tooth #36; (b) Clinical photo after apical root resection showing very narrow buccal bone plate due to furcation bone loss and osteotomy for apical surgery; (c) Post-operative radiograph; (d) 3-month follow up radiograph showing increased apical to furcal bone loss; (e) 5-month follow up radiograph showing complete bone loss of apex to furcation.

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  Figure 5 Post-operative radiographs and clinical photos during surgery of 4 cases in Figure 1. (a), (d), (g), and (j), post-operative radiograph of each case; (b), (e), (h), and (k), clinical photos during apical surgery, showing narrow but intact buccal marginal bone; (c), (f), (i), and (l), 4, 9, 9 and 10-year follow-up radiographs after surgery, showing complete healing of apical lesion.

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