Management of intracanal separated instruments.

By Madarati AA, Hunter MJ, Dummer PM.

Date: 01/2013
Journal: JOE

Summary:

Purpose: To

(1) review the literature regarding treatment options, influencing factors, and complications and

(2) suggest a decision-making process for their management.

Materials/Methods:

– An online search was conducted in peer-review journals listed in PubMed to retrieve clinical and experimental studies, case reports, and review articles

Impact of Retained Separated Instruments on Root Canal Treatment Outcome:

-SS fragments are inert and does not not exhibit corrosion after 2 years.

 

-separated instrument usually hinders or blocks access to the apical canal terminus and thus compromises the effectiveness of cleaning and shaping procedures, which may affect the treatment outcome.

 

-A favorable outcome (success rate 89%) was found in teeth with vital and necrotic pulps without periapical lesions. By contrast, when a periapical lesion was present at the time of instrument separation, the success rate reduced considerably to 47%. (Grossman, 1969)

 

-Later studies reported no effect of retained separated instruments on treatment outcome.

Management Options

-Can be managed with orthograde or surgical approaches

-Orthograde approaches are: attempts to remove the fragment, attempts to bypass the fragment, or cleaning/shaping and filling of the root canal to the level of the fragment.

Factors Influencing Removal of Separated Instruments:

Tooth Factors (anatomic factors that are dictated by the type of tooth, the cross-sectional shape and diameter of the root canal, position of the fragment within the root canal, location of the fragment with regard to root canal curvature, as well as the radius and degree of root canal curvature. (Figure4)

Separated Instrument Factors (Type, Design, and Length)

Operator Factors

Patient Factors

 

Techniques Used for Removing the Separated Instrument:

–      Chemical Solvents (EDTA)

Mini Forceps (Steiglitz forceps)

Broach and Cotton: If the separated fragment is a barbed broach and not tightly wedged in the root canal, another small barbed broach with a small piece of cotton roll twisted around it can be inserted inside the root canal to engage the fragment; then the whole assembly is withdrawn.

Wire Loops: A wire loop can be formed by passing the 2 free ends of a 0.14-mm wire through a 25-gauge injection needle from the open end until they slide out of the hub end. By using a small mosquito hemostat, the wire loop can be tightened around the upper free part of the fragment, and then the whole assembly can be withdrawn.

Hypodermic Surgical Needles: The beveled tip of a hypodermic needle can be shortened to cut a groove around the coronal part of the fragment by rotating the needle under light apical pressure (Fig.5)

-Braiding of Endodontic Files

Techniques Used for Removing the Separated Instrument:

 

Masserann Instruments: The Masserann kit consists of 14 hollow cutting-end trephine burs (sizes 11–24) ranging in diameter from 1.1–2.4 mm and 2 extractors (tubes into which a plunger can be advanced). The trephines are used in a counterclockwise fashion to trough around the coronal portion of the fragment.

Extractors:  The Endo- Extractor system (Roydent) has 3 extractors of different sizes and colors (red 80, yellow 50, and white 30). Each extractor has its corresponding trephine bur that prepares a groove around the separated instrument.

Post Removal System: Ruddle system, consists of 5 tubes. The smallest has an outside diameter of approximately 1.5 mm and internal threads that mechanically engage the most coronal aspect of any separated instrument with a diameter of 0.60 mm or greater.

Canal Finder System: The system produces a vertical movement with maximum amplitude of 1–2 mm that decreases when the speed increases (assists in bypassing a fragment)- (Fig.7)

File Removal System:  Figure12