Root perforations: aetiology, management strategies and outcomes. The hole truth.

By Saed SM, Ashley MP, Darcey J

Date: 06/2016
Journal: BRITISH DENTAL JOURNAL

Summary:  

Purpose:   to emphasize that root perforations can occur both during and after endodontic treatment and to focus on the non-surgical and surgical management of root perforations and describes how selection of the appropriate treatment depends on an accurate diagnosis

Iatrogenic perforations : 

Coronal third :  often result while attempting to locate and open canals , Middle third : if there is over-instrumentation or use large file or instrument (GG) in narrow small canals .

Apical third : stiff instruments in curved canals and passing endodontic files to aggressively through the apical constriction. Careless post space preparation may result in both apical and strip perforation.

Pathological Perforations:  can result from root resorption or caries. Internal  resorption occurs after trauma, pulpal inflammation and pulpectomy.

External inflammatory root resorption can occur following damage to the cementum and periodontal ligament cells on the root surface and  control depend on type, site and extent. Extensive carious lesions the  treatment may require  RCT, crown lengthening, root extrusion or resection. Unfortunately, perforation in most of these cases results the tooth unrestorable.

Epidemiology:  frequency of root perforations has been reported to range from 3% to as high as 10%. According to Kvinnsland et al., 53% of iatrogenic perforations occur during insertion of posts, the remaining 47% occur during routine RCT.

Diagnosis: Iatrogenic perforations are  identified from the profuse bleeding that follows the injury  , sudden unexpected pain if no LA is given ,zero reading in apex locator ,OM,radiographs  and CBCT

Outcomes: If the perforation in close proximity to the supra crestal attachment there may be proliferation of epithelium and, ultimately formation of the periodontal pocket . Prognosis of the tooth depends on site, size , time and the material with which repair is made .  MTA(setting time 4 hours),Biodentine (12 min)  (Table 1)

Management: The aim of perforation management is regeneration of healthy periodontal tissues against the perforation without persistent inflammation or loss of periodontal attachment.

Non-surgical management : the success depends on removing the contaminants, repairing under aseptic conditions,  hemostasis and skillful placement of a restorative material.

Coronal perforation : in supracrestal perforations we can place  either RMGI or MTA  If MTA is used wait for setting before placing the restoration . Sluyk et al. showed that at a time range of 72 h, the resistance to dislodgement improves significantly. 

Middle third perforation  : It is necessary to be cautious  in placing the instruments in the original canal and not the perforation. This is facilitated by pre-bending root canal instruments and filing away from the defect. There are two options for repairing these perforations:  Sealing the defect with MTA before  obturating the canal apical to the perforation or after obturation . Apical third perforation : difficult to manage. difficult. Using MTA to restore these defects may be impossible  so warm GP with sealer is a good alternative. Consideration should be given to the options of apical surgery or extraction if  pathology and symptoms persist.

Surgical management of perforations:  surgical management is indicated if either the case is not responding to non-surgical treatment, or if management of the affected periodontium is required. It is reported that success rates may vary between 30% and 80% which further repeates  the fact that non-surgical repair should always be carried out whenever possible.

Conclusion : Prevention of iatrogenic damage is an essential part of all healthcare interventions. Table 2 contains some tips on good preventive strategies.