Post on 11-Apr-2015
description
transcript
PROCEDURAL ACCIDENTS
Dr.Moeen Al Weshah
DEFINITION
Endodontic mishaps or procedural accidents
are those unfortunate accidents that happen
during treatment, some owing to inattention to
detail, others being totally unpredictable
TORABINEJAD AND LEMON IN “ENDODONTICS
PRINCIPLES AND PRACTICE” :
I. Perforations during access preparation
II. Accidents during cleaning and shaping
III. Accidents during obturation
IV. Accidents during post space preparation
Proper access opening is key to ensure an errorless procedure during cleaning and shaping, if not gained it would be beginning of procedural failure.
Main errors during access opening are
Access Cavity Perforations
Treatment of the Wrong Tooth
Missed Canals
Damage to an Existing Restoration
ACCIDENTS DURING ACCESS PREPARATION
The prime objective of an access cavity is to provide an unobstructed or straight-line pathway to the apical foramen.
Accidents, such as excess removal of tooth structure or perforation, may occur during attempts to locate canals.
Failure to achieve straight-line access is often the main etiologic factor for other types of intracanal accidents.
ACCESS CAVITY PERFORATIONS
CAUSES
A. Lack of attention to degree of axial inclination in relation to adjacent teeth or bone gouging and perforation usually through indirct visioin (cast crown)
*Could be avoided by periodic review of bur tooth relationship, transillumination, magnification and radiographs
B. Searching for chamber or canal orifices through underprepared access cavity
C. Failure to recognize when a bur passes through a small or flattened pulp chamber in multirooted teeth
RECOGNITION:
Sudden pain while local anesthesia was adequate
Sudden hemorrhage perodontium > bone? Dry field?
Burning pain or bad taste during NaOCl- irrigation
Reading on AL. RG mal-positioned file.
Early detection is vital to treatment as cleaning and shaping of PL or bone worsen the prognosis and resulted in severe postoperative pain
Inform your patient of questionable prognosis and refer to endodontist.
TYPES OF PERFORATION
DURING ACCESS CAVITY PREPARATION
Lateral root perforation Supracrestal easy repair full crown- covering the defect
Infracrestal repair-- poorest prognosis, ortho-extrusion
or periosurery. Or internal repair using MTA
Furcation perforation Direct: punched out defect if dry GIC or composite otherwise MTA
Immediately
Stripping: Furcation side of the coronal surface inner surface
i.e the opposite surface of the lateral perforation (multirooted)
this will lead to periodontal pocket. Failure will be due to leakage
of repair material. MTA improves the prognosis of nonsurgical repair
compared with other materials.
PREVENTION
Clinical and radiographical examinations
Tilted, misoriented casting, calcified chamber
Even 2D angulated RG give will give at least distorted 3D
Operative procedures Postpone RD application in difficult cases
Constricted chamber or canals must be sought with small amount of dentine removed at a time
Use safe non cutting edge burs after de-roofing the chamber (Endo Z, pulp shaper bur)
RG and AL to detect early perforation
Use split dam group isolation
A bur is secured in the hole with cotton pellet and RG taken: Direct facial RG and Angled RG
Use fiberoptic light to locate canals , direct light beam through the access and illuminate the pulp chamber
Use of magnifications loupes or microscope
TREATMENT:
Nonsurgical Prefered to surgical if possible, difficulties because of
visibility
hemorrhage
control, management and sealing ability of repair material
should be sealed immediately MTA best prognosis
Surgical Complex restorative procedures
Demand good oral hygiene
Options if bone level allows: bicuspidation or hemisection or intentional reimplantation (IR)
IR: consider if more than one problem present
PROGNOSIS
Depend on many variables:
Location
Length of root trunk
Size of the defect, <1 mm
Presence/absence of periodontal communication
Time lapse between perforation and repair
Sealing ability of restorative material
Competence of the dentist/patient oral hygiene
Treatment of the wrong tooth can be so easily prevented. One should make sure through testing, examining, and radiography that one has confirmed which tooth requires treatment
Open the access cavity before applying the rubber dam
TREATMENT OF THE WRONG TOOTH
Additional canals in the mesial
roots of maxillary molars and the
distal roots of mandibular molars
are the most frequently missed.
Second canals in lower incisors,
and second canals and bifurcated
canals in lower premolars, as well
as third canals in upper premolars
are also missed.
One must prepare adequate
occlusal access
MISSED CANALS
Porcelain crowns are the most susceptible to
chipping and fracture.
When one is present, use a water-cooled,
smooth diamond point and do not force the
bur, let it cut its own way .
Also, do not place a rubber dam clamp on the
gingiva of any porcelain or porcelain-faced
crown
DAMAGE TO AN EXISTING RESTORATION
ACCIDENTS DURING CLEANING AND SHAPING
Ledge formation
Root perforation
Artificial canal creation
Instrument separation
Extrusion of irrigation solution
Aspiration or ingestion and tissue emphysema
LEDGE FORMATION
Occur when WL can no longer be negotiated and canal patency lost
Causes:
Inadequate straight line access into the canal
Inadequate irrigation and lubrication
Excessive enlargement of curved canals with large files
Debris packing in canal ‘s apical portion
PREVENTION
I. PREOPERATIVE
A. curvatures: mostly severe coronal curvature. Apical curvature with improper access preparation
B. length: longer canals more prone than shorter
C. initial size: small diameter canals are more prone to ledging.
II: OPERATIVE:
optimum straight line access, frequent irrigation and recapitulation, good lubrication. flexible
files
1/8-1/4 REAMING motion in the apical part and away from furcation area. Each file should be
loose before next size is used.
MANAGEMANT AND PROGNOSIS
Management: size 10 ss, 2-3 mm sharply bent toward canal curvature, with good lubrication,
with picking motion. once original WL gained work with reaming motion and up and down to
remove debris
Prognosis: depend on amount of debris remains
Usually short and cleaned apical ledge have good prognosis
Should clinical or radiographic evidence of failure arises,
refer to endodontist
CREATING AN ARTIFICIAL CANAL
Causes: ledge, insist on WL , usually by ss files
Management: confirm WL AL,radiograph and PP
adjust WL and create a stop and obturate, how?
If there is no perforation: warm compaction
technique
Perforated: the defect should be repaired internally
with MTA or surgically
Prognosis:
depend on the ability to renegotiate, prepare and
obturate the original canal.
Renegotiated canals had good prognosis while un-
negotiated especially when large portion is missed
is poor. If symptoms arises, surgery to resect un-
instrument portion?
ROOT PERFORATION
Could be perforated at any level
A. Apical: overinstrumnetation:
Incorrect WL or inability to maintain WL cause zipping of apical foramen.
Signs: bleeding, pain, sudden loss of apical stop,
Prevention: take WL with apex locator and consider change of WL during/after CS
Treatment: establish new WL seat , use of MTA apically to prevent extrusion of filling materials
Success will depend on size and shape of the defect reverse funnel,
open apex, the need to interfere surgically will influence outcome.
B. Lateral Midroot perforatrion: inability to maintain curvature due to curvature plus size and inflexibility of larger files
Treatment, bypassed the ledge if possible and seal the perforation site, use mild irrigation concentration
Prognosis buccal has better prognosis. Corrective techniques include repair of perforation site, root resection to perforation level, root amputation, hemisection, extraction
C. Coronal root perforation: occur during access preparation as the operator try canal orifice or during flaring procedure with files GG
peeso reamer. Poorest long term prognosis
SEPARATED INSTRUMNET
Due to limited flexibility and strength combined with improper use (overuse or excessive force applied)
Recognition: the file comes out shorter than the length when it was inserted. RG: to confirm
Inform the patient
Prevention: knowing the limits of the instrument, copious irrigation, avoid instrument overuse, examine your instrument before insertion
Small files should be replaced frequently
Your set of files should be replaced if possible
NiTi show no signs of weakening
Unwound or twisted files should be replaced
Examine your instrument under magnification
SEPARATED INSTRUMNET Treatment:
Attempt to remove, bypass or up to the
segment if couldn’t bypass or remove.
Try to bend 2-3 mm of small size 8 or
10 s.s file as ledge treatment, if
bypassed you can use ultrasonics,
barbed broaches headstrom files to try to
remove the instrument
Prognosis:
How much undebridment before separation
and unobturated portion apical to the
instrument.
Poor prognosis if small files at apical portion
or beyond the apex.
Surgery should be considered if there are
symptoms.
EXTRUSION OF IRRIGANT
SODIUM HYPOCHLORITE ACCIDENT
Caused by wedging of the needle in the canal or sometimes out of perforation with forceful expression of the irrigant (NaOCl-) to periradicular tissues which could be a life threatening emergency.
Signs and symptoms: sudden prolonged and sharp pain followed by rapid diffuse swelling.
Prevention: keep irrigating needles loose in the canal, don’t wedge the needle, don’t make excessive force while irrigating and use proper(perforated) needles for irrigation
Use side vented needles not subcutaneous needles for irrigation
Treatment: palliative, sometimes analgesics anti-inflammatory medication with no antibiotics at initial management, reassurance, follow up on daily basis.
INSTRUMENT ASPIRATION OR INGESTION
One of the most serious mishaps
87% swallowed and the rest aspirated
The patient should be referred immediately to medical service
All aspirated and some swallowed will need surgical intervention by thoracic surgery or abdominal surgery
Relatively uncommon
Two actions may cause this to happen:
a blast of air to dry a canal
exhaust air from a high-speed drill directed toward the tissue and not evacuated to the rear of the handpiece during apical surgery.
Emphysema from a blast of air down the canal is more likely to happen with youngsters, in whom the canals in anterior teeth are relatively large.
The usual sequence of events is rapid swelling, erythema, and crepitus.
Although the problem should not be treated lightly, the majority of reported cases have followed a benign course to total recovery.
Prevention is simple: use paper points. Do not blow air directly
down an open canal, and employ a handpiece that exhausts the spent air out the back of the handpiece rather than into the operating field.
TISSUE EMPHYSEMA
ACCIDENTS DURING OBTURATION:
The quality of obturation reflects canal preparation (cleaning
and shaping) which is the key for proper obturation)
A. underfilling
Natural barrier
Ledge
Insufficient flaring
Poorly adapted master cone
Inaqedate condensation pressure this doesn’t mean using
excessive force on spreader or plugged which will result in root
fracture
Always take cone fit radiograph and if suspicious before you
sear excessive gutta percha.
Treatment: redo.
ACCIDENTS DURING OBTURATION:
B. overfilling
A consequence of over-preparation through apical constriction or lack of
proper taper in prepared canals
Either naturally (open apex, resorption) or due to over preparation will mean
absence of matrix against which to condense which will result in extrusion
of filling material due to uncontrolled condensation (compaction)
The presence of seat is necessary
Prevention: cone fit RG
Treatment: redo if possible, surgery
Prognosis will depend on quality of apical seal , biocompatibility of
extruded, host response, toxicity and sealing ability of the root end filling
material
C. Vertical Root Fracture
Etiology
Causative factors include root canal treatment procedures and associated factors such as post placement. The main cause of vertical root fracture is post cementation, and the second in importance is excessive application of condensation forces to obturate an underprepared or overprepared canal.
Prevention
As related to root canal treatment procedures, the best means of preventing vertical root fractures are appropriate canal preparation and use of balanced pressure during obturation. A major reason for flaring canals is to provide space for condensation instruments.
Finger spreaders produce less stress and distortion of the root than their hand counterparts.
Indicators
Long-standing vertical root fractures are often associated with a narrow periodontal pocket or sinus tract stoma, as well as a lateral radiolucency extending to the apical portion of the vertical fracture.
To confirm the diagnosis, a vertical fracture must be visualized. Exploratory surgery or removal of the restoration is usually necessary to visualize this mishap
Accidents during obturation:
To prevent root perforation, gutta-percha may be removed to the desired level with heated pluggers or electronic heating devices
Attempting to remove gutta-percha with a drill only can result in perforation.
When a canal is prepared to receive a post, drills should be used sequentially, starting with a size that fits passively to the desired level.
preparation may result in perforation at any level.
indicators
Appearance of fresh blood during post space preparation is an indication for the presence of a root perforation.
The presence of a sinus tract stoma or probing defects extending to the base of a post is often a sign of root fracture or perforation.
Radiographs often show a lateral radiolucency along the root or perforation site.
ACCIDENTS DURING POST SPACE PREPARATION
Treatment and Prognosis
the prognosis of teeth with root perforation during post space preparation depends on the root size, location relative to epithelial attachment, and accessibility for repair.
Management of the post perforation generally is surgical if the post cannot be removed. If the post can be removed, nonsurgical repair is preferred .
Teeth with small root perforations that are located in the apical region and are accessible for surgical repair have a better prognosis than those that have large perforations, are close to the gingival sulcus, or are inaccessible.
ACCIDENTS DURING POST SPACE
PREPARATION
PROTECTION GLASS