Effective Management of Acute Endodontic Pain
Literature Review and Clinical Protocol
Frederick R. Liewehr, DDS, MS
Practitioners have divergent educational backgrounds, training, and experience, where they have learned different ways to manage emergencies, as well as minimize them. It is an unfortunate fact of life that no matter what we do clinically, emergencies and “flare-ups” – unscheduled return trips to the office – are going to occur. Studies generally claim that the occurrence is quite low, less than 5%.1,2 The working definition of a flare-up varies widely between studies, so it is very difficult to find the true incidence. Presented here is essentially a distillation of the literature made into practical clinical protocol that can be followed, along with a chart for reference. While this will not eliminate all interappointment pain or flare-ups, it will provide an understanding of the underlying mechanisms to eliminate many of them.
The key to management of endodontic patients is to distinguish between cases with vital pulps and those with nonvital pulps. The rational and resultant protocol for treatment is quite different for these conditions.
In the case of a vital pulp, the patient presents with pain because extravasation of fluid (due to acute inflammation of the pulp) causes pressure within the noncompliant walls of the pulp chamber (Figure 1). This in turn produces pressure on the pulpal nociceptors—a toothache. Once the clinician has accessed the tooth, this problem is essentially solved by his or her removal of the roof of the chamber. A pulpotomy of the coronal pulp, with a diamond bur just barely beyond the orifices of the canals, can then be performed (Figure 2). There is usually no need to remove radicular pulp, because it is much less inflamed than the coronal pulp and also more fibrous. Most importantly, if it is injured but not removed, the patient will feel pain after the procedure is complete. Unless the canals are to be cleansed and shaped, they should not be entered during an emergency visit. The pulp should be removed atraumatically to just below the level of the orifices of the canals.
When the pulp in the canals is very inflamed, and hemorrhage is noted, the pulp should be removed to the level where it stops bleeding. Sometimes that means instrumenting the roots completely, as if it were a necrotic case. Usually, however, mixing calcium hydroxide powder with the accumulating blood will form a paste and stop the bleeding. Once the pulpotomy has been performed, a thin wisp of cotton should be placed over the openings to the root canals, and the chamber filled with Intermediate Restorative Material (IRM) (Figure 3). Take the tooth out of the occlusion,3,4 and tell the patient that it is going to be sore when the anesthetic wears off, and for several days afterward. The patient should be advised to avoid chewing on the tooth and of the potential discomfort that he or she may undergo. Additionally, a nonsteriodal anti-inflammatory drug (NSAID) should be prescribed. NSAIDs work much better when a therapeutic blood level of the drug is maintained. Each morning, have the patient self-assess the pain. If it feels better, and the vast majority will by the second or third day, fourth at the most, he or she does not need to take NSAIDs. If he or she is in pain, have him or her take them as prescribed, all day long, and reassess the following morning. No antibiotics are necessary as they do nothing to prevent discomfort or reduce the incidence of flare-ups.1,5-7
In the case of a nonvital pulp, pressure on pulpal nerves is of no concern. The only pain of concern is extraradicular, caused by inflammation outside the tooth due to bacteria and their by-products within the pulp (Figure 4). In this case, the focus is on eliminating the bacteria and by-products and ensuring that they do not reach the periapical area. Unfortunately, as soon as the tooth is opened, the environment within which the bacteria live is changed. There are many theories as to what causes a flare-up, but one reason may be that many of the bacteria of concern are facultative. In a closed tooth, they use anaerobic glycolysis to produce energy and make two molecules of adenosine triphosphate (ATP) from one molecule of glucose. Once the tooth is opened, however, the bacteria can use oxygen, avail themselves of the Kreb’s cycle and the electron transport system, and make an additional 36 molecules of ATP. It may be that when a clinician opens the tooth and exposes these bacteria to oxygen, they get a whole new lease on life and present a significant danger to the patient, rather than being relatively quiescent.8 Of course, this is just one theory among many, and part of many other complex changes that are brought about by opening the tooth. The point is that simply opening these teeth and then trying to close them again can cause pain or even a flare-up.
So what to do? To put it succinctly, the more pulp, debris, and bacteria that are removed, the less chance the patient will experience a flare-up. In a vital tooth, putting a file into vital radicaular pulp, especially if it is not going to be removed, will injure it and cause pain to the patient. In the nonvital pulp, as much pulp as possible should be removed to reduce the sheer number of bacteria. In this case, the concern of injuring the pulp is nonexistent.
That being said, the file in a canal serves as a plunger. The primary objective is to avoid extruding bacteria and their by-produces out through the apex, which is what will happen when a file is placed deep into the canal.9 Can this be avoided altogether? While this is unlikely, if the amount of debris is minimized in the coronal and middle thirds of the canal, along with flaring the canal so that the file does not fit so tightly, it should reduce the plunger effect. In addition, rotary files have been shown to extrude less material than conventional hand files. A crown-down rotary technique that removes the material as the procedure is performed, rather than trying to establish a final working length first, is optimal.10 The length of the tooth can be approximated by laying a file on the preoperative film, backing up a couple of millimeters and passively cleaning to that level. Copious irrigation to flush out all the bacteria and debris should be performed. The apical 3 mm or 4 mm should not be entered until the coronal and middle thirds have been cleansed and shaped (Figure 5). Then, gently use a small file that slides easily to the estimated working length. A radiograph should be taken to confirm the working length. Instrument minimally using a rotary technique (hand or motor-driven) to the working length (Figure 6). The goal at this point is merely to remove as much debris as possible without extruding it, and then to place a commercial mixture of calcium hydroxide, or a very thin mixture of calcium hydroxide powder and water, to kill residual bacteria and to dissolve necrotic tissue.11 Instrumenting through or beyond the apex of the tooth does not reduce postoperative pain and swelling, and may increase the chance of a flare-up due to extruded material.12
Once the canal has been prepared, irrigated, and dried, the calcium hydroxide is placed, and the tooth is closed to ensure that it is not in hyperocclusion (Figure 7). The patient does not require antibiotics unless there are systemic sings and/or symptoms (ie, fever, trismus, malaise), the infection is spreading rapidly, or it is in a dangerous area. Antibiotics will not reduce the incidence of interappointment pain or flare-ups.1,5-7 The patient should also be given postoperative instructions as before. The patient should be advised that in the event the paint increases and swelling or a temperature develops, he or she will need to be recalled.
Occasionally, the unthinkable will happen—the patient will call in pain. The first rule of dental care is that a diagnosis is needed before the patient can be treated. When the patient arrives, vital signs should be taken and a thorough examination performed. Signs of systemic involvement, such as fever, lymphadenopathy and diffuse swelling—signs that the patient may have an infection that his or her body is having difficulty coping—should be looked at closely. Also look for pain to percussion and palpation, and possibly mobility, which indicate involvement beyond the confined of the tooth.
With proper postoperative instructions, patients should not present with minor discomfort. The patient’s expectations should be managed so that he or she will not be surprised by some postoperative soreness. If the patient had pain and a vital pulp initially, and presents with a toothache that is the same or worse, the problem is either another tooth or damage to the residual radicular pulp in the tooth that was accessed. In this case, either treat the other tooth, or perform a complete pulpectomy of the tooth in which the pulpotomy was performed previously. The objective is to remove any residual injured pulpal tissue. No antibiotics are indicated, because infection is not the problem.
If the patient had a nonvital pulp, the amount of bacteria and debris removed may not have been sufficient. In this case, cleansing and shaping of the canals must be completed, and calcium hydroxide should be placed again. The objective is to entirely remove the bacteria and bacterial by-products that produced the inflammatory response. If there is swelling, an incision and drainage may be indicated. Antibiotics are indicated only if the patient has diffuse swelling, swelling in a dangerous area, or systemic signs such as fever. Any patient who has been prescribed antibiotics should understand what to expect after the emergency treatment (eg, resolution of fever in 24 hours, no increase in swelling). The patient should be given a 24-hour number to call if signs and/or symptoms worsen. Having the staff check with the patient daily for the first 72 hours will allow his or her progress to be monitored and will be very much appreciated by the patient.
Emergencies are a part of dentistry. Patients will have interappointment pain, and flare-ups will happen. There is, however, much that can be done by the dental professional to minimize the occurrence (Table 1).
*Former Chairman, Department of Endodontics, Virginia Commonwealth University, Richmond, VA; Current Chief of Endodontics: Hunter Holmes McGuire VAMC, Richmond, VA; private practice Richmond, VA.
- Walton RE, Chiappinelli J. Prophylactic penicillin: Effect on post treatment symptoms following root canal treatment of asymptomatic periapical pathosos. J Endod 1993;19(9):466-470
- Mor C, Rotstein I, Friedman S. Incidence of interappointment emergency associated with endodontic therapy. J Endod 1992;18(10):509-511
- Rosenberg PA, Babick PJ, Schertzer L, Leung A. The effect of occlusal reduction on pain after endodontic instrumentation. J Endod 1998;24(7):492-496
- Torabinejad M, Dorn SO, Eleazer PD, et al. Effectiveness of various medications on postoperative pain following root canal obturation. J Endod 1994;20(9):427-431
- Fouad AF, Rivera EM, Walton RE. Penicillin as a supplement in resolving the localized acute apical abscess. Oral Surg Oral Med Oral pathol Oral Radiol Endod 1996;81(5):590-595
- Pickenpaugh L, Reader A, Beck M, et al. Effect of prophylactic amoxicillin on endodontic flare-up in asymptomatic, necrotic teeth. J Endod 2001;27(2):53-56
- Henry M, Reader A, Beck M. Effect of penicillin on postoperative endodontic pain and swelling in symptomatic necrotic teeth. J Endod 2001;27(2):117-123
- Seltzer S, Naidorf IJ. Flare-ups in endodontics: I. Etiological factors. 1985. J Endod 2004;30(7):476-481
- Vande Visse JE, Brilliant JD. Effect of irrigation on the production of extruded material at the root apex during instrumentation. J Endod 1975;1(7):243-246
- Reddy SA, Hicks ML. Apical extrusion of debris using two hand and two rotary instrumentation techniques. J Endod 1998;24(3):180-183
- Behnen MJ, West LA, Liewehr FR, et al. Antimicrobial activity of several calcium hydroxide preparations in root canal dentin. J Endod 2001;27(12):765-767
- Nist E, Reader A, Beck M. Effect of apical trephination on postoperative pain and swelling in symptomatic necrotic teeth. J Endod 2001;27(6):415-420
Table 1: Emergency Treatment Protocol
| ||Vital Pulp ||Non-Vital Pulp|
Cause of pain
Pulpal swelling in noncompliant environment
Bacteria and/or by-products escape into periapical tissues
Create space for remaining pulpal tissue
Remove bacteria and by-products
Injuring remaining vital tissue
Extrusion of pulpal debris into periapical tissues
Remove coronal pulp tissue to level of orifices
Remove as much pulpal debris as possible without extruding it
Only is systemic signs and symptoms are present