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The EndoFiles Fax

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The EndoFiles Fax
October 2001: Volume 2 Issue VI

A Periodic Review of Current Clinically Related Endodontic Topics
Tips and hints for the practicing Dentist

With editorial comment provided by:
Robert M. Kaufmann DMD MS (Endo)

Instant Online referrals or Call 783–2971

Pain Control in Endodontics

The ability to provide skillful, successful, comfortable endodontics depends on proper case management. Efficient, accurate diagnosis, profound anesthesia and correct postoperative care must be combined in order to provide comfortable treatment. Lack of proper diagnostics, rushed or incomplete blocks and inadequate post operative care can all cause unnecessary patient discomfort and have stigmatized endodontics. Lets examine a few key areas that we need to consider so patient comfort may be achieved.

Pretreatment Factors
Endodontic pain control starts with proper diagnosis. This means that the clinician accurately identifies the offending pulp and its relative pathologic condition as it moves from Normal to Reversible Pulpitis to Irreversible Pulpitis and then to Necrosis. Cold, hot and cavity tests must be used ROUTINELY and the patient's symptoms must be reproduced in the chair. I suggest Endo Ice on a cotton pellet for cold tests and flamed Hygienic White Dental Stopping for heat tests. Electric pulp tests have relatively little use because of their unreliability. I have not used an electric pulp tester in many years. Suspected necrotic teeth should never be anesthetized during access because the cavity test is the final confirmation of loss of vitality and accurate diagnosis. If sensitive tissue is encountered in the more apical sections of the canal or in one canal of a multi-rooted tooth, the dam should be removed and only then should anesthesia be provided. Adherence to this rule ensures that vital teeth with periodontally related radiolucencies are never mistakenly opened by misdiagnosis.

Local Anesthesia - Products
Patients that exhibit late stages of Reversible Pulpitis (exaggerated and lengthened responses to cold) can react differently to anesthesia than patients with late stage Irreversible Pulpitis (exaggerated and delayed response to heat). I currently perform all endodontic procedures with Ultracaine DS Forte (Articaine 4% with 1/100,000 epi.). It can be purchased through Hansamed ( in Canada) 1-800-363 2876. Septodont claims that their brand of Articaine (Septonest) is equivalent. I have tried both and prefer Ultracaine. This is entirely a subjective opinion. Whatever anesthetic you prefer, it is essential that the operator or assistant test vital teeth with Endo Ice to ensure that adequate anesthesia are present. Minimal or delayed responses are not acceptable because even these responses indicate that pulpal nerve fibers are still active. In that case, change the injection site, angle or technique and then reapply the anesthetic. Remember - a minimal injection of anesthetic applied in exactly the right spot will profoundly anesthetize a patient. Continuing to inject copious amounts of anesthetic in a fruitless attempt to provide anesthesia can only cause frustration and discomfort for the patient.

Tips for the Maxilla
The standard PSA (Posterior Superior Alveolar) block for maxillary molars is relatively easy to do and achieves profound anesthesia in almost all cases. Do not forget to provide palatal injections for all premolars and molars. This is essential. Molar PSA injections must also be augmented with an infiltration injection mesial to the MB root, since innervation can also occur mesial to the tooth being blocked. Most problems with anterior teeth anesthesia have to do with not placing the anesthesia near enough to the apex (too for coronally). Inconsistency with maxillary anesthesia suggests that operator technique is faulty and that an anatomic reference text should be consulted. This is beyond the scope of this article.

Tips for the Mandible
Mandibular molars can sometimes be difficult to anesthetize. This is most common in cases of a "hot tooth" where thermal responses are acute. An adequate mandibular block is achieved only when the patient exhibits lip signs, anesthesia of that side of the tongue and no response to thermal tests. The famous "Supplemental" or "Mylohyoid" injection should be routinely used as well. The beveled needle is inserted slightly disto-lingual to the root being anesthetized and an injection in made in the attached gingiva at a level just above the muco-gingival junction. A small "bleb" of anesthetic should be raised in the mucosa while this is being done. Minimal amounts are required. Infiltration on the buccal aspect will also help prevent sensitivity to placement of rubber dam clamps along the buccal gingiva. Anterior teeth can sometimes safely be anesthetized with infiltration near the Mental foramen. However, for endodontics, I prefer a mandibular block. Crossover from one central incisor to the other generally is only a concern in surgical procedures. If it occurs, provide a Mental infiltration for the side opposite to the tooth being worked on. Infiltration over the apex rarely works because of the thickness of the cortex.

PDL Injection
Virtually all research has shown that a special "Ligmaject" gun is not required. Regular 30, or 27 gauge short needles can used to provide this method of anesthesia. But PDL "guns" can make the injection easier to apply. (I don't own one.) Tips for PDL injections: Bend the needle to a 45-degree angle. Place the bevel of the needle up against the root surface and apply heavy apical pressure at the level of the bend with the opposite thumb or finger. Maintain steady firm injection pressure on the plunger for at least 30 seconds per site of imjection on all sides of the tooth e.g./ mandibular molar - MB, DB, ML, DL - 4 sites. Avoid injecting large amounts of anesthetic into the gingiva or papilla. This is especially important if you use higher concentrations of epinephrine. (1/50,000). I can cause sloughing and cratering post op. Be careful when using glass carpules, this kind of pressure can cause them to shatter. Patients should always wear eye protection when injections of this type are being given.

Stabident and X-Tip Systems
Some clinicians have had some success with the use of these. In this method, the overlying gingiva is anesthetized, a latch trefine bur is used to perforate the cortical bone and then a guide sleeve is inserted that allows direct deposit of anesthetic intra-osseously. Care must be used to prevent drilling into the PDL/apices or roots. Some cardiac effects have been reported with the use of vasoconstrictors so use caution. Anesthetics without vasoconstrictors are being recommended. I have not used this system because I believe that the initial gingival anesthesia can be uncomfortable and that a properly placed intrapulpal injection offers a quicker, more reliable method when the pulp is to be removed. However, intra-osseous systems may offer a good alternative for operative dentistry when endodontics is not indicated.

Intra-Pulpal Anesthesia
If it is necessary to have a patient "feel" something in order to get good anesthesia, compassionate care dictates that you do it quickly, efficiently and with informed consent. One of the most useful tools of last resort in endodontic therapy is the ability to provide profound anesthesia through the use of intra-pulpal injection. Many clinicians avoid this method because of the fear of patient discomfort or because they have had inconsistent results (with correspondingly angry patients!) THIS METHOD SHOULD ONLY BE USED WHEN ALL OTHER ANESTHESIA METHODS HAVE BEEN UNSUCCESSFULLY TRIED. There is NO question that patient's experience a momentary, sharp discomfort. However, in cases of a "hot tooth" (lower molars especially) this is much preferred over repeated unsuccessful blocks or prolonged attempts to access canals with sensitive vital tissue.The theory behind the Intra-Pulpal injection is to rapidly raise the pulpal pressure beyond the trigger level. Once this level is reached, the nerves depolarize once and then are rendered unresponsive. Studies have shown that this can be accomplished with any liquid (such as saline). Anesthetic solution is generally used because of the convenience of applying it via needle and syringe.

There are several keys to gain profound anesthesia with this technique:
(1) Always warn the patient that they will feel 2 sharp sensations, lasting only a second or two. You MUST prepare the patient first.
(2) Remove the existing restoration. Try to avoid dentin.
(3) Again, warn the patient when you are about to penetrate dentin or expose the pulp. Choose the highest pulp horn or the area where the dentin is the thinnest. Quickly expose the pulp with a new, sharp 2 round bur (dry) turning at maximum revolution. Use a jabbing motion with the bur. The patient will start for a moment. Reassure them.
(4) Do not enlarge the exposure site. It is important to be able to lock the needle in the exposure. Use a 30 Gauge short needle and apply a right angle bend. If necessary, apply pressure to the area of the bend with your opposite index finger or thumb (forcing the needle tip into the exposure site) ALWAYS warn the patient before you inject.
(5) The patient will feel a momentary sharp sensation as the needle is introduced and the intrapulpal pressure exceeds the limit of depolarization. Anesthesia is now complete. With proper technique, anesthesia will be profound along the entire length of the canal. In some calcified, multiple canal cases it may occasionally be necessary to supplement this technique with an individual intracanal injection.
Be careful to inject ONLY in cases where vital tissue (NOT necrotic contents) is present. Only a minute amount is necessary. I believe that skillful, appropriate use of this technique should be part of every clinician's armamentarium.

The Acute Apical Abscess
Patients presenting with an acute apical abscess will, by definition, have a necrotic pulp (in a single canal tooth) or a necrotic chamber and at least one necrotic canal (in a multi-rooted tooth). In most cases, attempting an infiltration injection in this area is a waste of time because the altered pH of the area (due to the swelling acute inflammation) often limits the effectiveness of the anesthetic. It can only serve to make the area more tender. Injecting large amounts of anesthetic in an attempt to obtain anesthesia can actually spread the infection through the fascial planes. The key to controlling the symptoms is to establish drainage through the necrotic canal. If a dam cannot be placed because of tenderness, the mobile tooth should be stabilized in the fingers and a high speed 2 or 4 round bur (maximum revs) should be used to gain access to the chamber and/or canal. Speed is essential for comfort so you must work quickly and be confident in your ability to perform a rapid access cavity without risk of perforation. In many cases the tooth will drain immediately, the drainage moving from stages of purulent, then bloody, and then clear fluids. Occasionally a small instrument (size #15 file) may have to be used just slightly past the apex to encourage drainage. Pain relief is generally quite dramatic within a few minutes of establishing drainage. In cases where no drainage occurs through the canal, incision and drainage can be attempted through the soft tissue only if there is an area of fluctuance where the abscess has pointed. A small amount of anesthetic can be administered to anesthetize the gingiva or mucosa in preparation for incision. There is no advantage in doing an I&D in cases of "Cellulitis" (firm, non fluctuant swelling) because the abscess has not yet localized and drainage will be minimal. In such cases, the tooth is left open, an antibiotic (PenVK 300 mg 2 stat 1qid or Clindamycin 150 mg 2 stat 1 tid or qid) and analgesics (Ibuprophen 400 mg and/or Tylenol #3 q4h) should be prescribed along with intraoral warm saline rinses. External heat packs must be avoided. The patient should be re-appointed for I&D in 24 or 48 hrs. once the area has localized.

Intracanal Medicaments
Phenol and Formaldehyde based intracanal canal medicaments such as Cresatin and Formocresol have generally fallen into disfavor. They can sometimes actually increase discomfort because of their ability to irritate periapical tissues when excessive amounts are used. Many endodontists (including me) haven't used them for a decade or more. We understand that cleaning and shaping of the canal system is more important than medicaments for pain control. In those rare occasions where a medicament is needed (wet canals, for example), CaOH is the medicament of choice. I prefer to use Vitapex (Diadent brand Iodoform and CaOH) in a syringe-based delivery system because of its ease of application close to the apex.

Pain Control After Treatment
In order to ensure comfort after treatment, control of instruments, irrigation and filling materials during treatment is essential. Most post operative endodontic symptoms are related to either overworking of the apex, inadequate debridement or failure to relieve occlusion, especially after single appointment procedures. In the case of overinstrumentation, it is important to maintain accurate working lengths. This means using both radiographic and electronic (Apex Locators) methods. Performing endodontic treatment without an apex locator is simply unacceptable in modern dentistry and is not the standard of care. It prevents overinstrumentation and ensures instruments are at the apex and not beyond. Repeated placement of large patency files past the apex or excess sealer puffs can cause PDL inflammation and post op extrusion. It is very important to relieve the occlusion after treatment to allow for a small amount of supraeruption that occurs post-operatively. This is especially important in single appointment treatment. Patients can easily be kept comfortable by reducing the occlusion immediately after treatment and medicating them with anti-inflammatories such as Ibuprophen 400 mg. Heavy amounts of Codeine based narcotic analgesics should not be routinely necessary, especially in cases of elective or vital/noninfective endodontics. If you find yourself frequently reaching for the narcotic Rx pad after many of your endo procedures, then you need to re-evaluate your technique.

A Last word about Antibiotics
The events of Sept. 11 and the recent Anthrax scare have resulted in many people medicating themselves unnecessarily with antibiotics. As we have heard, leading physicians have discouraged the use of antibiotics such as Ciprofloxacin as a preventive measure. We know that if such warnings are not taken seriously, Cipro and its related antibiotics may not be as effective in the future and will contribute to proliferation of resistant strains of other bacteria. Similarly, dentists must realize that antibiotics are rarely effective in controlling acute pain of pulpal origin. With the exception of the acute apical abscess, serious pulpal pain is almost always associated with an inflamed, partially vital or dying pulp that has poor circulation. It is much more important that the patient be diagnosed quickly and correctly so that the offending tooth may be opened and the canals cleaned. Prescribing antibiotics is not a substitute for good diagnostic technique. Giving a patient an antibiotic "just in case" is poor clinical practice. If you can't open the tooth, or just do not wish to, consider referral to an Endodontist before you reach for the antibiotic prescription. Unless the patient is exhibiting signs of a large infection (swelling, mobility and lymphadenopathy) such prescriptions are contraindicated.

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