- Email: [email protected]
Endodontic flare-ups: a prospective study
Endodontic flare-ups: a prospective study Vanessa de Oliveira Alves, DDS, São Paulo, Brazil SÃO PAULO DENTAL ASSOCIATION
The objective of this prospective clinical study was to evaluate the incidence of flare-ups (pain and/or swelling requiring endodontic interappointment and emergency treatment) and identify the risk factors associated with their occurrence in patients who received endodontic treatment from June 2006 to June 2007 at the endodontics clinic of the São Paulo Dental Association (APCD), Jardim Paulista branch, São Paulo, Brazil. The incidence of flare-ups was 1.71% out of 408 teeth that had received endodontic therapy. Statistical analysis using the chi-squared test (P ⬍ .05) indicated a direct correlation between the flare-up rate and the presence of a periradicular radiolucency. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:e68-e72)
Endodontic flare-ups are those occurrences of pain and/or swelling resulting from a session of endodontic treatment and requiring an emergency interappointment and active treatment.1 The rates reported in the literature range from 1.4% to 16%. This could be attributed to the fact that each study follows a particular protocol, thus using different samples and criteria to evaluate the stage of pain and/or swelling.2-6 Several factors have been studied to elucidate which factors could be correlated with the occurrence of flareups. These include the number of sessions to complete the treatment7; intracanal medication used8; host factors, such as gender, age, and dental group3; presence of preoperative pain of periapical origin6; pulpal diagnosis5; periradicular diagnosis1; type of treatment, whether initial treatment or retreatment9; presence of irritants inside the radicular canal system6; apical extrusion of debris; and whether or not apical patency was maintained during preparation.10 The objective of the present prospective clinical study was to evaluate the incidence of flare-ups and to identify the risk factors that may be associated with this occurrence after initial treatment and retreatment in patients who were endodontically treated from June 2006 to June 2007 at the endodontics clinic of the São Paulo Dental Association (APCD), Jardim Paulista branch, São Paulo, Brazil. MATERIALS AND METHODS Data were collected from all patients with endodontic needs, who were seen by students attending the Endodontics Specialist, São Paulo Dental Association; MSc student, São Leopoldo Mandic Dental Research Center. Received for publication Sep 1, 2009; returned for revision May 5, 2010; accepted for publication May 15, 2010. 1079-2104/$ - see front matter © 2010 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2010.05.014
e68
specialization course in endodontics, during a 13month period. Endodontic treatment was provided to patients under controlled and standardized conditions and under the supervision of the attending faculty to ensure quality and consistency of treatment. All of the students were fully instructed to administer treatment according to the principles and philosophy of the specialization program. A total of 266 patients were seen, for a total of 408 treated teeth. All patients were informed of the aims and design of the study, and written informed consent was obtained from each of the participants before their inclusion. Each patient’s record consisted of the following data: pulpal and periradicular diagnosis of the tooth; presence of preoperative pain; type of medication used before treatment; type of treatment performed; number of sessions needed to complete the endodontic treatment; and whether or not apical patency was maintained while preparing the root canal. Each patient was anesthetized with a local anesthetic. A rubber dam was placed, and the operative field was decontaminated with 2.5% sodium hypochlorite (NaOCl). Conventional straight-line access preparations were performed. Chemomechanical preparation was performed in all of the teeth, using a modified crown-down progressive enlargement technique, with cervical enlargement by way of Gates-Glidden burs size 070 and 090 (Maillefer, Ballaigues, Switzerland), and files activated by an endodontic rotary system. An electronic apex locator (Root ZX; J. Morita, Tokyo, Japan) was used to determine the working length 1 mm short of the apical foramen. Apical patency, whenever possible, was confirmed with a small file after each larger file was used. Irrigation was carried out with 1 mL 2.5% sodium hypochlorite, delivered by a 30-G needle, after applying each bur and file size. Final irrigation with 17% ethylenediaminetetra-acetic acid was activated with ul-
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Table I. Occurrence of flare-ups according to age group
Table III. Occurrence of flare-ups according to arch/ dental group
Flare-ups
Flare-ups
Age, y
No. of teeth
n
%
Dental group
⬍21 21-30 31-40 41-50 51-60 ⬎60
45 94 115 93 44 17
0 2 2 2 1 0
0 2.12 1.73 2.15 2.27 0
Maxillary* Anterior Premolar Molar Mandibular† Anterior Premolar Molar
P ⫽ .9284 (not statistically significant at ␣ ⫽ .05).
Table II. Occurrence of flare-ups according to gender Flare-ups Gender
No. of teeth
n
%
Male Female
144 264
3 4
2.08 1.51
No. of teeth
n
%
84 72 80
0 3 1
0 4.16 1.25
28 33 111
0 0 3
0 0 2.70
*P ⫽ .1235 (not statistically significant at ␣ ⫽ .05). †P ⫽ .4322 (not statistically significant at ␣ ⫽ .05).
Table IV. Occurrence of flare-ups according to pretreatment medication Flare-ups
P ⫽ .6728 (not statistically significant at ␣ ⫽ .05).
trasound for 1 minute in each canal to improve the efficacy of the smear layer removal procedure. In retreatment cases, root canal preparations were completed after removal of the previous root canal filling with Gates-Glidden burs and hand files as described above. Most treatments were completed in a single visit. However, additional sessions were required in the event of an abscess, when there was lack of time, when the patient felt tired, or in cases of greater complexity. Under these circumstances, a nonsetting calcium hydroxide powder (Fórmula e Ação, São Paulo, SP, Brazil) mixed with a sterile saline solution was used to fill the canals, and a temporary seal was placed using Cavit (Espe-Premier, Norriston, PA, USA). At the end of each appointment, the attending dentist instructed the patient on how to proceed by saying: “Expect the tooth to be sore for 1 or 2 days. Over-thecounter medication should be enough to take care of this initial soreness. However, should the pain persist, or particularly if it seems to be getting worse, please call me. Also call if you notice continuous swelling. If you have any other questions or problems, be sure to contact me.” In the cases where there was pain and/or swelling, an emergency interappointment was arranged. Appropriate treatment, consisting of further canal instrumentation, was performed. These cases were classified as positive occurrences of flare-up. The flare-up rates were registered and expressed as percentages, and then compared through the chisquared test (P ⬍ .05) using StatXact software (Cytel Software Corp., Cambridge, MA, USA).
Pretreatment medication
No. of teeth
n
%
No medication Analgesics/antiinflammatories/ antibiotics
327 81
5 2
1.52 2.46
P ⫽ .5597 (not statistically significant at ␣ ⫽ .05).
RESULTS Four hundred eight teeth were included in the study. Seven of these required emergency treatment, thus yielding a flare-up rate of 1.71%. There were no statistically significant differences in the incidence of flareups regarding the following factors: age (Table I); gender (Table II); maxillary versus mandibular teeth (Table III); intake of medication preoperatively (Table IV); performance of initial treatment or retreatment (Table V); number of visits to complete the treatment (Table VI); or whether apical patency was maintained (Table VII). Although the analysis of the pulpal diagnosis factor revealed 6 cases of flare-up in teeth with nonvital pulps, this factor did not influence the incidence of flare-ups significantly (Table VIII). However, the periradicular status was correlated positively with the occurrence of flare-ups. In this group, the occurrence of a periradicular radiolucent alteration was responsible for 3.04% of the emergencies, representing a statistically significant increase compared with teeth showing normal radiographic appearance in the periapical region (Table IX). DISCUSSION This study revealed a low incidence of flare-ups during endodontic treatment (1.71%). These results are similar to those obtained by Imura and Zuolo,5 Trope,12 and Siqueira et al.,6 who used the following criterion
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de Oliveira Alves
Table V. Occurrence of flare-ups according to treatment modality
Table VIII. Occurrence of flare-ups according to pulpal diagnosis
Flare-ups
Flare-ups
Treatment modality
No. of teeth
n
%
Diagnosis
No. of teeth
n
%
Initial treatment Retreatment
283 125
3 4
1.06 3.20
Normal Pulpal inflammation Pulp with no vitality
77 83 248
0 1 6
0 1.20 2.41
P ⫽ .1249 (not statistically significant at ␣ ⫽ .05).
P ⫽ .3327 (not statistically significant at ␣ ⫽ .05).
Table VI. Occurrence of flare-ups according to no. of appointments Flare-ups Sessions Single Multiple
No. of teeth 240 168
n
Table IX. Occurrence of flare-ups according to periradicular diagnosis Flare-ups
%
2 5
0.83 2.97
P ⫽ .1009 (not statistically significant at ␣ ⫽ .05).
Diagnosis
No. of teeth
n
%
Normal appearance Presence of lesion
244 164
2 5
0.81 3.04
P ⬍ .0001 (statistically significant at P ⬍ .01).
Table VII. Occurrence of flare-ups according to apical patency procedure Flare-ups Patency
No. of teeth
n
%
Positive Negative
315 93
5 2
1.58 2.15
P ⫽ .7132 (not statistically significant at ␣ ⫽ .05).
for flare-ups: the occurrence of severe spontaneous pain and/or swelling after an intracanal intervention, requiring an emergency interappointment and active treatment. The low incidence of flare-ups reinforces the fact that canal therapy may be considered to be a routine dental treatment as long as biologic principles are observed and scientifically based contemporary techniques are used. Analysis regarding the influence of a patient’s age and gender, as well as of the tooth and arch under consideration, did not show statistically significant differences in the flare-up rates. These results corroborate the findings of other authors.5,12 Conversely, a retrospective study carried out by Torabinejad et al.3 found a positive correlation between flare-up rates and age, gender, and dental arch. The initial diagnosis is an important factor when evaluating painful exacerbations after an endodontic intervention. In the present study, there was a statistically significant difference in the occurrence of flareups in cases presenting with periradicular radiolucencies. An increased incidence of pain in these teeth may be explained by the presence of bacteria and their by-products within the root canals. Iqbal et al.13 concluded that the incidence of flare-ups was low and that the presence of a periapical lesion was the most
important factor for its occurrence during root canal treatment. Siqueira9 reported that causes of flare-ups comprise both mechanical and chemical factors, and/or microbial injuries to the pulp, as well as extrusion of contaminated debris into the periradicular tissues. A study carried out by Izu et al.14 demonstrated that contaminated patency files can potentially contaminate the periapical tissues. This considered, the clinician should be aware of the risks of using large instruments for maintaining patency. This procedure may result in severe periradicular injury, lead to the lack of an apical stop, and extrude a large amount of infected debris, which predispose to postoperative discomfort and/or jeopardize the outcome of the endodontic therapy.15 In the present study, the procedure of maintaining apical patency did not correlate with the incidence of flare-ups, a result similar to that obtained by Torabinejad et al.3 Both our study and that of Torabinejad et al. used the crown-down technique, which produces less apically extruded debris, as previously reported by Al Omari and Dummer16 and Favieri et al.11 The results of the present study demonstrated that teeth with pain and/or swelling of periradicular origin did not present any statistically significant difference regarding flare-up rates. Torabinejad et al.,3 however, reported that patients with pain and/or swelling before treatment were more prone to flare-ups than those with no preoperative complaints. In the present study, there was no statistically significant correlation between the use of preoperative medication and flare-up rates, corroborating the findings of Walton and Fouad.1
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Analysis of the type of treatment performed–whether initial treatment or retreatment–showed no statistically significant difference regarding the incidence of flareups. This was consistent with the study carried out by Siqueira et al.,6 who considered apically extruded microorganisms and the incomplete chemical-mechanical preparation of the apical part of the root canal as the main causes of flare-ups. In the present prospective study, there was no statistically significant difference between the incidence of flare-ups and the number of sessions. Studies comparing single and multiple sessions, such as those carried out by Fox et al.,17 Al-Negrish and Habahbeh,18 and Figini et al.,20 did not find any difference regarding the incidence of postoperative pain whether in 1- or 2-visit endodontic treatments. Nevertheless, studies by Yodas et al.,8 Oginni and Iudoye,19 and Ghoddusi et al.21 obtained contrary results, reporting an increase in the incidence of postendodontic pain in single-session procedures. Sathorn et al.22 reviewed the evidence regarding postoperative pain/flare-ups and concluded that there was no evidence to show a significant difference in the prevalence of postoperative pain/flare-ups after either single- or multiple-visit root canal treatment. The low incidence of flare-ups in the present study may be attributed to the use of an atraumatic crown-down preparation technique and to compliance with biologic principles; these factors could be even more relevant than the number of treatment sessions for successful completion. Based on the results obtained in this study, it should be borne in mind that flare-ups often occur when treating teeth with evidence of periradicular radiolucency. In such cases, the appropriate technique should be chosen to reduce the amount of debris extruded apically. Although psychosocial and cultural factors were not the object of our study, the self-reported preappointment pain level of study patients has been associated with a greater likelihood of flare-ups. Law et al.23 reported that the most successful psychosocial factors in predicting flare-ups were: 1) the highest level of distress in the 6 hours before the appointment; and 2) the desire to control the anticipated unpleasantness associated with the treatment. The reasons for the differences cannot be readily explained but could relate to different patient populations, varying treatment modalities, and other methods of assessment.23 Fear of dentists and dental procedures, anxiety, apprehension, and many other psychologic factors also may influence the patient’s pain perception and reaction thresholds.24 Previous traumatic dental experiences appear to be significant factors in the production of anxiety and apprehension in dental patients.25 Furthermore,
de Oliveira Alves e71
pain perception is a highly subjective and variable experience modulated by multiple physical and psychologic factors, and pain reporting is influenced by factors other than the experimental procedure.26 Further research analyzing possible relationships between cultural and other subjective factors on one hand, and more objective factors on the other, such as those investigated in our study, may shed light on alternative strategies to deal with flare-ups. The author is grateful to Professors Mario Luis Zuolo and José Eduardo de Mello Junior for their extremely valuable guidance throughout the research and development of this prospective clinical study. REFERENCES 1. Walton R, Fouad A. Endodontic interappointment flare-ups: a prospective study of incidence and related factors. J Endod 1992;18:172-7. 2. Morse DR, Furst ML, Lefkowitz RD, D’Angelo D, Esposito JV. A comparison of erythromycin and cefadroxil in the prevention of flare-ups from asymptomatic teeth with pulpal necrosis and associated periapical pathosis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1990;69:619-29. 3. Torabinejad M, Kettering JD, Mcgraw JC, Cummings RR, Dwyer TG, Tobias TS. Factors associated with endodontic interappointment emergencies of teeth with necrotic pulps. J Endod 1988;14:261-6. 4. Trope M. Relationship of intracanal medicaments to endodontic flare-ups. Endod Dent Traumatol 1990;6:226-9. 5. Imura N, Zuolo ML. Factors associated with endodontic flareups: a prospective study. Int Endod J 1995;28:261-5. 6. Siqueira JF, Rocas IN, Favieri A, Machado AG, Gahyva SM, Oliveira JC, Abad EC. Incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy. J Endod 2002;28:457-60. 7. Di Renzo A, Gresla T, Johnson BR, Rogers M, Tucker D, Begole EA. Postoperative pain after 1- and 2-visit root canal therapy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;93: 605-10. 8. Yodas O, Topuz A, Isci AS, Oztunc H. Postoperative pain after endodontic retreatment: single- versus two-visit treatment. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:483-86. 9. Siqueira JF. Microbial causes of endodontic flare-ups. Int Endod J 2003;36:453-63. 10. Arias A, Azabal M, Hidalgo JJ, Macorra JC. Relationship between postendodontic pain, tooth diagnostic factors, and apical patency. J Endod 2009;35:189-92. 11. Favieri A, Gahyua SM, Siqueira JF. Extrusão apical de detritos durante instrumentação com instrumentos manuais e acionados a motor. J Bras Endodon 2000;1:60-4. 12. Trope M. Flare-up rate of single-visit endodontics. Int Endod J 1991;24:24-7. 13. Iqbal M, Kurtz E, Kohli M. Incidence and factors related to flare-ups in a graduate endodontic programme. Int Endod J 2009;42:99-104. 14. Izu KH, Thomas SJ, Zhang P, Izu AE, Michalek S. Effectiveness of sodium hypochlorite in preventing inoculation of periapical tissues with contaminated patency files. J Endod 2006;32:624-7. 15. Siqueira JF. Aetiology of the endodontic failure: why welltreated teeth can fail. Int Endod J 2001;34:1-10. 16. Al Omari MA, Dummer PMH. Canal blockage and debris extrusion with eight preparation techniques. J Endod 1995;21:154-8.
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17. Fox J, Atkison JS, Dinin AP, Greenfield E, Hechtman E, Reeman CA, et al. Incidence of pain following one-visit endodontic treatment. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1970;30:123-30. 18. Al-Negrish AR, Habahbeh R. Flare up rate related to root canal treatment of asymptomatic pulpally necrotic central incisor teeth in patients attending a military hospital. J Dent 2006;34:635-40. 19. Oginni AO, Udoye CI. Endodontic flare-ups: comparison of incidence between single and multiple visits procedures in patients attending a Nigerian teaching hospital. Odont Stomat Tropic 2004;27:23-7. 20. Figini L, Lodi G, Gorni F, Gagliani M. Single versus multiple visits for endodontic treatment of permanent teeth: a Cochrane systematic review. J Endod 2008;34:1041-47. 21. Ghoddusi J, Ghoddusi J, Javidi M, Zarrabi MH, Bagheri H. Flare-ups incidence and severity after using calcium hydroxide as intracanal dressing. N Y State Dent J 2006;72:24-8. 22. Sathorn C, Parashos P, Messer H. The prevalence of postoperative pain and flare-up in single- and multiple-visit endodontic treatment: a systematic review. Int Endod J 2008;41:91-99.
23. Law AS, Logan HL, Walton RE. Identification of a psychosocial model as a predictor of flare-ups. J Endod 1992;18: 192-3. 24. Berggren U, Meynert G. Dental fear and avoidance: causes, symptoms, and consequences. J Am Dent Assoc 1984;109:247-51. 25. O’Keefe EM. Pain in endodontic therapy: preliminary study. J Endod. 1976;2:315-9. 26. Bender IB. Pulpal pain diagnosis: a review. J Endod 2000;26: 175-9.
Reprint requests: Vanessa de Oliveira Alves, DDS Rua Faustolo, 1101, apto. 172 CEP: 05041-001 São Paulo, SP Brazil [email protected]
The objective of this prospective clinical study was to evaluate the incidence of flare-ups (pain and/or swelling requiring endodontic interappointment and emergency treatment) and identify the risk factors associated with their occurrence in patients who received endodontic treatment from June 2006 to June 2007 at the endodontics clinic of the São Paulo Dental Association (APCD), Jardim Paulista branch, São Paulo, Brazil. The incidence of flare-ups was 1.71% out of 408 teeth that had received endodontic therapy. Statistical analysis using the chi-squared test (P ⬍ .05) indicated a direct correlation between the flare-up rate and the presence of a periradicular radiolucency. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:e68-e72)
Endodontic flare-ups are those occurrences of pain and/or swelling resulting from a session of endodontic treatment and requiring an emergency interappointment and active treatment.1 The rates reported in the literature range from 1.4% to 16%. This could be attributed to the fact that each study follows a particular protocol, thus using different samples and criteria to evaluate the stage of pain and/or swelling.2-6 Several factors have been studied to elucidate which factors could be correlated with the occurrence of flareups. These include the number of sessions to complete the treatment7; intracanal medication used8; host factors, such as gender, age, and dental group3; presence of preoperative pain of periapical origin6; pulpal diagnosis5; periradicular diagnosis1; type of treatment, whether initial treatment or retreatment9; presence of irritants inside the radicular canal system6; apical extrusion of debris; and whether or not apical patency was maintained during preparation.10 The objective of the present prospective clinical study was to evaluate the incidence of flare-ups and to identify the risk factors that may be associated with this occurrence after initial treatment and retreatment in patients who were endodontically treated from June 2006 to June 2007 at the endodontics clinic of the São Paulo Dental Association (APCD), Jardim Paulista branch, São Paulo, Brazil. MATERIALS AND METHODS Data were collected from all patients with endodontic needs, who were seen by students attending the Endodontics Specialist, São Paulo Dental Association; MSc student, São Leopoldo Mandic Dental Research Center. Received for publication Sep 1, 2009; returned for revision May 5, 2010; accepted for publication May 15, 2010. 1079-2104/$ - see front matter © 2010 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2010.05.014
e68
specialization course in endodontics, during a 13month period. Endodontic treatment was provided to patients under controlled and standardized conditions and under the supervision of the attending faculty to ensure quality and consistency of treatment. All of the students were fully instructed to administer treatment according to the principles and philosophy of the specialization program. A total of 266 patients were seen, for a total of 408 treated teeth. All patients were informed of the aims and design of the study, and written informed consent was obtained from each of the participants before their inclusion. Each patient’s record consisted of the following data: pulpal and periradicular diagnosis of the tooth; presence of preoperative pain; type of medication used before treatment; type of treatment performed; number of sessions needed to complete the endodontic treatment; and whether or not apical patency was maintained while preparing the root canal. Each patient was anesthetized with a local anesthetic. A rubber dam was placed, and the operative field was decontaminated with 2.5% sodium hypochlorite (NaOCl). Conventional straight-line access preparations were performed. Chemomechanical preparation was performed in all of the teeth, using a modified crown-down progressive enlargement technique, with cervical enlargement by way of Gates-Glidden burs size 070 and 090 (Maillefer, Ballaigues, Switzerland), and files activated by an endodontic rotary system. An electronic apex locator (Root ZX; J. Morita, Tokyo, Japan) was used to determine the working length 1 mm short of the apical foramen. Apical patency, whenever possible, was confirmed with a small file after each larger file was used. Irrigation was carried out with 1 mL 2.5% sodium hypochlorite, delivered by a 30-G needle, after applying each bur and file size. Final irrigation with 17% ethylenediaminetetra-acetic acid was activated with ul-
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Table I. Occurrence of flare-ups according to age group
Table III. Occurrence of flare-ups according to arch/ dental group
Flare-ups
Flare-ups
Age, y
No. of teeth
n
%
Dental group
⬍21 21-30 31-40 41-50 51-60 ⬎60
45 94 115 93 44 17
0 2 2 2 1 0
0 2.12 1.73 2.15 2.27 0
Maxillary* Anterior Premolar Molar Mandibular† Anterior Premolar Molar
P ⫽ .9284 (not statistically significant at ␣ ⫽ .05).
Table II. Occurrence of flare-ups according to gender Flare-ups Gender
No. of teeth
n
%
Male Female
144 264
3 4
2.08 1.51
No. of teeth
n
%
84 72 80
0 3 1
0 4.16 1.25
28 33 111
0 0 3
0 0 2.70
*P ⫽ .1235 (not statistically significant at ␣ ⫽ .05). †P ⫽ .4322 (not statistically significant at ␣ ⫽ .05).
Table IV. Occurrence of flare-ups according to pretreatment medication Flare-ups
P ⫽ .6728 (not statistically significant at ␣ ⫽ .05).
trasound for 1 minute in each canal to improve the efficacy of the smear layer removal procedure. In retreatment cases, root canal preparations were completed after removal of the previous root canal filling with Gates-Glidden burs and hand files as described above. Most treatments were completed in a single visit. However, additional sessions were required in the event of an abscess, when there was lack of time, when the patient felt tired, or in cases of greater complexity. Under these circumstances, a nonsetting calcium hydroxide powder (Fórmula e Ação, São Paulo, SP, Brazil) mixed with a sterile saline solution was used to fill the canals, and a temporary seal was placed using Cavit (Espe-Premier, Norriston, PA, USA). At the end of each appointment, the attending dentist instructed the patient on how to proceed by saying: “Expect the tooth to be sore for 1 or 2 days. Over-thecounter medication should be enough to take care of this initial soreness. However, should the pain persist, or particularly if it seems to be getting worse, please call me. Also call if you notice continuous swelling. If you have any other questions or problems, be sure to contact me.” In the cases where there was pain and/or swelling, an emergency interappointment was arranged. Appropriate treatment, consisting of further canal instrumentation, was performed. These cases were classified as positive occurrences of flare-up. The flare-up rates were registered and expressed as percentages, and then compared through the chisquared test (P ⬍ .05) using StatXact software (Cytel Software Corp., Cambridge, MA, USA).
Pretreatment medication
No. of teeth
n
%
No medication Analgesics/antiinflammatories/ antibiotics
327 81
5 2
1.52 2.46
P ⫽ .5597 (not statistically significant at ␣ ⫽ .05).
RESULTS Four hundred eight teeth were included in the study. Seven of these required emergency treatment, thus yielding a flare-up rate of 1.71%. There were no statistically significant differences in the incidence of flareups regarding the following factors: age (Table I); gender (Table II); maxillary versus mandibular teeth (Table III); intake of medication preoperatively (Table IV); performance of initial treatment or retreatment (Table V); number of visits to complete the treatment (Table VI); or whether apical patency was maintained (Table VII). Although the analysis of the pulpal diagnosis factor revealed 6 cases of flare-up in teeth with nonvital pulps, this factor did not influence the incidence of flare-ups significantly (Table VIII). However, the periradicular status was correlated positively with the occurrence of flare-ups. In this group, the occurrence of a periradicular radiolucent alteration was responsible for 3.04% of the emergencies, representing a statistically significant increase compared with teeth showing normal radiographic appearance in the periapical region (Table IX). DISCUSSION This study revealed a low incidence of flare-ups during endodontic treatment (1.71%). These results are similar to those obtained by Imura and Zuolo,5 Trope,12 and Siqueira et al.,6 who used the following criterion
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de Oliveira Alves
Table V. Occurrence of flare-ups according to treatment modality
Table VIII. Occurrence of flare-ups according to pulpal diagnosis
Flare-ups
Flare-ups
Treatment modality
No. of teeth
n
%
Diagnosis
No. of teeth
n
%
Initial treatment Retreatment
283 125
3 4
1.06 3.20
Normal Pulpal inflammation Pulp with no vitality
77 83 248
0 1 6
0 1.20 2.41
P ⫽ .1249 (not statistically significant at ␣ ⫽ .05).
P ⫽ .3327 (not statistically significant at ␣ ⫽ .05).
Table VI. Occurrence of flare-ups according to no. of appointments Flare-ups Sessions Single Multiple
No. of teeth 240 168
n
Table IX. Occurrence of flare-ups according to periradicular diagnosis Flare-ups
%
2 5
0.83 2.97
P ⫽ .1009 (not statistically significant at ␣ ⫽ .05).
Diagnosis
No. of teeth
n
%
Normal appearance Presence of lesion
244 164
2 5
0.81 3.04
P ⬍ .0001 (statistically significant at P ⬍ .01).
Table VII. Occurrence of flare-ups according to apical patency procedure Flare-ups Patency
No. of teeth
n
%
Positive Negative
315 93
5 2
1.58 2.15
P ⫽ .7132 (not statistically significant at ␣ ⫽ .05).
for flare-ups: the occurrence of severe spontaneous pain and/or swelling after an intracanal intervention, requiring an emergency interappointment and active treatment. The low incidence of flare-ups reinforces the fact that canal therapy may be considered to be a routine dental treatment as long as biologic principles are observed and scientifically based contemporary techniques are used. Analysis regarding the influence of a patient’s age and gender, as well as of the tooth and arch under consideration, did not show statistically significant differences in the flare-up rates. These results corroborate the findings of other authors.5,12 Conversely, a retrospective study carried out by Torabinejad et al.3 found a positive correlation between flare-up rates and age, gender, and dental arch. The initial diagnosis is an important factor when evaluating painful exacerbations after an endodontic intervention. In the present study, there was a statistically significant difference in the occurrence of flareups in cases presenting with periradicular radiolucencies. An increased incidence of pain in these teeth may be explained by the presence of bacteria and their by-products within the root canals. Iqbal et al.13 concluded that the incidence of flare-ups was low and that the presence of a periapical lesion was the most
important factor for its occurrence during root canal treatment. Siqueira9 reported that causes of flare-ups comprise both mechanical and chemical factors, and/or microbial injuries to the pulp, as well as extrusion of contaminated debris into the periradicular tissues. A study carried out by Izu et al.14 demonstrated that contaminated patency files can potentially contaminate the periapical tissues. This considered, the clinician should be aware of the risks of using large instruments for maintaining patency. This procedure may result in severe periradicular injury, lead to the lack of an apical stop, and extrude a large amount of infected debris, which predispose to postoperative discomfort and/or jeopardize the outcome of the endodontic therapy.15 In the present study, the procedure of maintaining apical patency did not correlate with the incidence of flare-ups, a result similar to that obtained by Torabinejad et al.3 Both our study and that of Torabinejad et al. used the crown-down technique, which produces less apically extruded debris, as previously reported by Al Omari and Dummer16 and Favieri et al.11 The results of the present study demonstrated that teeth with pain and/or swelling of periradicular origin did not present any statistically significant difference regarding flare-up rates. Torabinejad et al.,3 however, reported that patients with pain and/or swelling before treatment were more prone to flare-ups than those with no preoperative complaints. In the present study, there was no statistically significant correlation between the use of preoperative medication and flare-up rates, corroborating the findings of Walton and Fouad.1
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Analysis of the type of treatment performed–whether initial treatment or retreatment–showed no statistically significant difference regarding the incidence of flareups. This was consistent with the study carried out by Siqueira et al.,6 who considered apically extruded microorganisms and the incomplete chemical-mechanical preparation of the apical part of the root canal as the main causes of flare-ups. In the present prospective study, there was no statistically significant difference between the incidence of flare-ups and the number of sessions. Studies comparing single and multiple sessions, such as those carried out by Fox et al.,17 Al-Negrish and Habahbeh,18 and Figini et al.,20 did not find any difference regarding the incidence of postoperative pain whether in 1- or 2-visit endodontic treatments. Nevertheless, studies by Yodas et al.,8 Oginni and Iudoye,19 and Ghoddusi et al.21 obtained contrary results, reporting an increase in the incidence of postendodontic pain in single-session procedures. Sathorn et al.22 reviewed the evidence regarding postoperative pain/flare-ups and concluded that there was no evidence to show a significant difference in the prevalence of postoperative pain/flare-ups after either single- or multiple-visit root canal treatment. The low incidence of flare-ups in the present study may be attributed to the use of an atraumatic crown-down preparation technique and to compliance with biologic principles; these factors could be even more relevant than the number of treatment sessions for successful completion. Based on the results obtained in this study, it should be borne in mind that flare-ups often occur when treating teeth with evidence of periradicular radiolucency. In such cases, the appropriate technique should be chosen to reduce the amount of debris extruded apically. Although psychosocial and cultural factors were not the object of our study, the self-reported preappointment pain level of study patients has been associated with a greater likelihood of flare-ups. Law et al.23 reported that the most successful psychosocial factors in predicting flare-ups were: 1) the highest level of distress in the 6 hours before the appointment; and 2) the desire to control the anticipated unpleasantness associated with the treatment. The reasons for the differences cannot be readily explained but could relate to different patient populations, varying treatment modalities, and other methods of assessment.23 Fear of dentists and dental procedures, anxiety, apprehension, and many other psychologic factors also may influence the patient’s pain perception and reaction thresholds.24 Previous traumatic dental experiences appear to be significant factors in the production of anxiety and apprehension in dental patients.25 Furthermore,
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pain perception is a highly subjective and variable experience modulated by multiple physical and psychologic factors, and pain reporting is influenced by factors other than the experimental procedure.26 Further research analyzing possible relationships between cultural and other subjective factors on one hand, and more objective factors on the other, such as those investigated in our study, may shed light on alternative strategies to deal with flare-ups. The author is grateful to Professors Mario Luis Zuolo and José Eduardo de Mello Junior for their extremely valuable guidance throughout the research and development of this prospective clinical study. REFERENCES 1. Walton R, Fouad A. Endodontic interappointment flare-ups: a prospective study of incidence and related factors. J Endod 1992;18:172-7. 2. Morse DR, Furst ML, Lefkowitz RD, D’Angelo D, Esposito JV. A comparison of erythromycin and cefadroxil in the prevention of flare-ups from asymptomatic teeth with pulpal necrosis and associated periapical pathosis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1990;69:619-29. 3. Torabinejad M, Kettering JD, Mcgraw JC, Cummings RR, Dwyer TG, Tobias TS. Factors associated with endodontic interappointment emergencies of teeth with necrotic pulps. J Endod 1988;14:261-6. 4. Trope M. Relationship of intracanal medicaments to endodontic flare-ups. Endod Dent Traumatol 1990;6:226-9. 5. Imura N, Zuolo ML. Factors associated with endodontic flareups: a prospective study. Int Endod J 1995;28:261-5. 6. Siqueira JF, Rocas IN, Favieri A, Machado AG, Gahyva SM, Oliveira JC, Abad EC. Incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy. J Endod 2002;28:457-60. 7. Di Renzo A, Gresla T, Johnson BR, Rogers M, Tucker D, Begole EA. Postoperative pain after 1- and 2-visit root canal therapy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;93: 605-10. 8. Yodas O, Topuz A, Isci AS, Oztunc H. Postoperative pain after endodontic retreatment: single- versus two-visit treatment. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:483-86. 9. Siqueira JF. Microbial causes of endodontic flare-ups. Int Endod J 2003;36:453-63. 10. Arias A, Azabal M, Hidalgo JJ, Macorra JC. Relationship between postendodontic pain, tooth diagnostic factors, and apical patency. J Endod 2009;35:189-92. 11. Favieri A, Gahyua SM, Siqueira JF. Extrusão apical de detritos durante instrumentação com instrumentos manuais e acionados a motor. J Bras Endodon 2000;1:60-4. 12. Trope M. Flare-up rate of single-visit endodontics. Int Endod J 1991;24:24-7. 13. Iqbal M, Kurtz E, Kohli M. Incidence and factors related to flare-ups in a graduate endodontic programme. Int Endod J 2009;42:99-104. 14. Izu KH, Thomas SJ, Zhang P, Izu AE, Michalek S. Effectiveness of sodium hypochlorite in preventing inoculation of periapical tissues with contaminated patency files. J Endod 2006;32:624-7. 15. Siqueira JF. Aetiology of the endodontic failure: why welltreated teeth can fail. Int Endod J 2001;34:1-10. 16. Al Omari MA, Dummer PMH. Canal blockage and debris extrusion with eight preparation techniques. J Endod 1995;21:154-8.
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17. Fox J, Atkison JS, Dinin AP, Greenfield E, Hechtman E, Reeman CA, et al. Incidence of pain following one-visit endodontic treatment. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1970;30:123-30. 18. Al-Negrish AR, Habahbeh R. Flare up rate related to root canal treatment of asymptomatic pulpally necrotic central incisor teeth in patients attending a military hospital. J Dent 2006;34:635-40. 19. Oginni AO, Udoye CI. Endodontic flare-ups: comparison of incidence between single and multiple visits procedures in patients attending a Nigerian teaching hospital. Odont Stomat Tropic 2004;27:23-7. 20. Figini L, Lodi G, Gorni F, Gagliani M. Single versus multiple visits for endodontic treatment of permanent teeth: a Cochrane systematic review. J Endod 2008;34:1041-47. 21. Ghoddusi J, Ghoddusi J, Javidi M, Zarrabi MH, Bagheri H. Flare-ups incidence and severity after using calcium hydroxide as intracanal dressing. N Y State Dent J 2006;72:24-8. 22. Sathorn C, Parashos P, Messer H. The prevalence of postoperative pain and flare-up in single- and multiple-visit endodontic treatment: a systematic review. Int Endod J 2008;41:91-99.
23. Law AS, Logan HL, Walton RE. Identification of a psychosocial model as a predictor of flare-ups. J Endod 1992;18: 192-3. 24. Berggren U, Meynert G. Dental fear and avoidance: causes, symptoms, and consequences. J Am Dent Assoc 1984;109:247-51. 25. O’Keefe EM. Pain in endodontic therapy: preliminary study. J Endod. 1976;2:315-9. 26. Bender IB. Pulpal pain diagnosis: a review. J Endod 2000;26: 175-9.
Reprint requests: Vanessa de Oliveira Alves, DDS Rua Faustolo, 1101, apto. 172 CEP: 05041-001 São Paulo, SP Brazil [email protected]