Comparison of electrosurgical and formocresol pulpotomy by GABRIELA SOTO

International Journal of Paediatric Dentistry 2002; 12: 177–182

Comparison of electrosurgical and formocresol pulpotomy procedures in children Blackwell Science, Ltd

J. A. DEAN1, R. B. MACK2, B. T. FULKERSON3 & B. J. SANDERS1 1Section

of Pediatric Dentistry, Indiana University School of Dentistry, Indianapolis, IN, of Pediatric Dentistry, University of the Pacific School of Dentistry, San Francisco, CA, 3Private Practice, Newburgh, IN, U.S.A. 2Department

Summary. Objectives. Although previous studies have examined the electrosurgical pulpotomy technique for primary teeth, no well-controlled, clinical human trials have been published. The purpose of this study was to prospectively compare electrosurgical pulpotomies vs. formocresol pulpotomies in human vital primary molar teeth. Design. Fifty children were randomly divided into two groups, 25 receiving an electrosurgical pulpotomy and 25 receiving a formocresol pulpotomy. Results. After at least 5 months postoperative observation time, the clinical and radiographic success rates for the electrosurgical groups were 96 and 84%, respectively; and for the formocresol group, 100 and 92%, respectively. Conclusion. There were no statistically significant differences between the success rates for the two groups at the P < 0·05 level as tested by Fisher’s exact test. This study failed to demonstrate a difference in the success rate between the electrosurgical and formocresol pulpotomy techniques.

Introduction The use of formocresol as a pulpal medicament was first introduced by Sweet in 1904 [1], and has since been a popular choice for use in the pulpotomy procedure, mainly because of its ease of use and clinical success. Even though the use of this pulpotomy medicament is common and produces very successful results, concerns regarding its use have led investigators to search for a safe and effective alternative [2–8]. The use of electrosurgery as a nonpharmacological pulpotomy technique has been well-documented and has proven to have merit [9]. This study was designed to compare the clinical and radiographic success of the electrosurgical and formocresol pulpotomy technique used on human primary molar teeth requiring vital pulp therapy

Correspondence: Jeffrey A. Dean, Riley Children’s Hospital, 702 Barnhill Drive, Suite 1110, Indianapolis, Indiana 46202– 5200, USA. Tel.: 317 274 4217, Fax: 317 278 0760, E-mail: jadean1@iupui.edu © 2002 BSPD and IAPD

secondary to carious involvement. The hypothesis of this study was the null hypothesis. Success rates for the electrosurgical pulpotomy technique were predicted to be comparable to the success rates for the formocresol pulpotomy technique. Methods and materials Patients were recruited from the paediatric patient population served by the dental clinics at the Indiana University School of Dentistry. This study was reviewed and approved by the Indiana University Institutional Review Board. Teeth were selected based upon the following criteria: (i) symptomless, carious exposure of the vital pulp; (ii) no clinical or radiographic evidence of pulpal degeneration, and (iii) possibility of proper restoration of primary molars. In addition to the patients meeting the criteria for the need of a pulpotomy in a primary molar, additional acceptance criteria required the study participants and/or their legal guardians to sign an 177

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informational letter of consent, required the patient to have no contraindications to pulpotomy in his/her medical history and to be willing to submit to periodic examination of the pulpotomised tooth. All pulpotomy procedures were performed by the principal investigator or co-investigators of this project to ensure consistency in the two techniques. Standardization of the investigators in the experimental technique was attempted by using a clinician with over 20 years of experience in performing the electrosurgical pulpotomy to provide joint instruction to them. The patients were assigned randomly (by the flip of a coin) to one of two treatment groups: electrosurgical (ES group) or formocresol (FC group). A subject with more than one tooth requiring a pulpotomy had only one tooth used in the study. Following profound local anaesthesia, quadrant rubber dam isolation, and occlusal reduction with a high-speed bur, dental caries were removed with a large slow-speed round bur. When pulpal exposure occurred, the roof of the coronal pulp chamber was removed with a high-speed bur. Following this, the coronal pulp was amputated with hand instruments and/or with the previously mentioned large slow-speed round bur without irrigation. In the experimental ES group, a series of large, sterile cotton pellets were placed into the chamber with pressure to obtain temporary haemostasis. The cotton pellets were then removed and the electrosurgery dental electrode (HyfrecatoR 705 A, Birtcher Medical Systems, Irvine, CA, U.S.A.) was immediately placed 1–2 mm above the tissue. The electrosurgery unit was set at 40% power (e.g. 12 watts) using the ‘high’ port only. The electrical arc was allowed to bridge the gap to the first pulpal stump for 1 s followed by a cool-down period of 5 s. Heat and electrical transfer was minimized by keeping the electrode as far away from the pulpal stumps and tooth structure as would still allow electrical arcing to occur. This procedure was repeated up to a maximum of 3 times at each pulpal orifice. Single current applications of 1 s each were performed to each orifice in a rotational sequence to avoid heat build-up in any one area of the tooth. After each current application, a new large sterile cotton pellet was placed with pressure on the next pulpal orifice to be electrosurgically treated to absorb any blood or tissue fluids before the next current application (e.g. pellet-electrode-pellet-electrode, etc.). When properly completed, the pulpal stumps appeared dry and completely blackened.

For the FC group, gross haemorrhage control was obtained using dry sterile cotton pellets. A sterile cotton pellet was then lightly moistened with full strength formocresol (Buckley’s, Sultan Chemists, Inc., Englewood, NJ, U.S.A.) and placed against the pulpal stumps for 5 min. If haemorrhage was not controlled, the pulpal stumps were checked and the pulp chamber cleansed and rinsed, followed by a second application of formocresol. If haemorrhage persisted, a pulpectomy was completed and the tooth eliminated from the study. When properly completed, the pulpal stumps were moist but free of haemorrhaging. For both groups, a reinforced zinc oxide-eugenol dressing was then placed directly on the radicular pulpal stumps and in the coronal pulp space. The interproximal surfaces were then prepared and the tooth bevelled and rounded with a high-speed bur. The tooth was then restored with a stainless steel crown. Either a recent preoperative or an immediate postoperative periapical radiographic film was obtained for each of the pulpotomised teeth. These patients were then placed on a 6-month recall program at which time a clinical examination and periapical radiograph of the tooth was obtained. Each tooth was evaluated for clinical success by the investigators of the study at the recall appointment. Clinical success was defined as the absence of pain, abscess, fistula or excessive mobility. The radiographs of the teeth in this study were evaluated by three different examiners with no knowledge as to which group the particular tooth was assigned. The examiners selected were full-time paediatric dentistry faculty members. The pulpotomy technique was judged a radiographic success or failure using criteria such as the presence of a normal periodontal ligament space, absence of pathologic root resorption or canal calcification and no periradicular radiolucency. The examiners had the option of rating the pulpotomy a success even though a radiographic change was associated with the tooth, if it was deemed by the examiners that the change was not associated with the pulpotomy itself (i.e. resorption secondary to an ectopic eruption) or that the change did not adversely affect the tooth’s prognosis for normal retention. In this study, failure rates were determined over the follow-up period for each technique based on the clinical and radiographic exam. The rates (clinical and radiographic) were compared using a Fisher’s exact test.

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Table 1. Age at time of treatment and post-operative observation time. Electrosurgical Age at time of treatment (months) Mean age Age range Post-operative observation time (months) Mean Range

Formocresol

63·6 26–97

68·2 32–126

10·9 6–31

11·5 5–25

Table 2. Radiographic pulpotomy success rates. Electrosurgical

Success Rate Normal Up to Exfoliation Normal at Last Observation Radiographic Change Noted Failure Rate

Formocresol

21/25 1/25 17/25 3/25 4/25

0·84

23/25 2/25 20/25 1/25 2/25

0·92

0·16

0·08

Results A total of 50 pulpotomies on 50 different patients were performed. There were 25 pulpotomies in each group (i.e. 25 in the electrosurgical and 25 in the formocresol). Table 1 lists the patient age at time of treatment and postoperative observation time for the ES and FC groups. The agreement between examiners for the success rates was measured using Kappa statistics. These were computed for each pair of examiners and the overall kappa was computed at 0·603, which is interpreted as ‘moderate to substantial agreement’ between the examiners. Only one of the 50 teeth demonstrated clinical failure. This tooth was in the ES group and it demonstrated radiographic failure, also. The clinical and radiographic success rates for the electrosurgical group were 96 and 84%, respectively; and for the formocresol group, 100 and 92%, respectively. Table 2 shows the radiographic success rates for the ES and FC groups and Figs 1–4 show radiographs of one successful and one failed case for each of the two groups. Although the ES radiographic failure rate was twice that of the FC group, this difference was not statistically significant at the P < 0·05 level using Fisher’s exact test. Discussion In this study, the examiners had the choice of rating each tooth a success, a success with a radiographic

Fig. 1. Pre- (a) and postoperative (b) radiographs of an electrosurgically pulpotomized tooth (mandibular left second primary molar) that was normal at the last observation. The pulpotomy was performed at age 54 months and the postoperative radiograph was taken at age 72 months.

or clinical change, or a failure based on the selected criteria. Of the three successful cases having radiographic or clinical changes in the electrosurgical group, one tooth had a poor fitting stainless steel crown, the other tooth had exudate expressed from the sulcus believed to be due to gingival irritation (probably caused by the stainless steel crown), and the third exhibited radiographic evidence of distal root resorption secondary to ectopic eruption of the maxillary first permanent molar (Fig. 5). Appointments for replacement of the ill-fitting crowns were scheduled and all three abnormalities were asymptomatic at the last evaluation appointment. These cases were difficult to categorize by the three examiners. The examiners felt that the radiographic changes were not directly related to the pulpotomies themselves, so they were judged successful even though they could not be included as ‘normal’. Of the failed ES cases, one case exhibited clinical signs and symptoms of morbidity and radiographic pathology

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Fig. 2. Immediate postoperative (a) and 6-month postoperative (b) radiographs of an electrosurgically pulpotomized tooth (mandibular left second primary molar) demonstrating internal resorption.

and was extracted 10 months after performing electrosurgical pulp therapy; a space maintainer was placed to prevent space loss. The other cases exhibited radiographic evidence of distal root resorption and/or internal root resorption without clinical signs or symptoms of morbidity. In the FC group, the tooth classified as a success having a radiographic or clinical change had exudate present around the gingival margin of the stainless steel crown. The examiners felt that this clinical change was not directly related to the pulpotomy itself, so it was judged a success even though it could not be included as ‘normal’. The tooth was asymptomatic with no signs of radiographic pathology. Of the failed cases, the first exhibited radiographic evidence of internal root resorption without clinical signs or symptoms of morbidity and the second case exhibited radiographic evidence of furcal pathology without clinical signs or symptoms of morbidity. In a recent prospective human study on the electrosurgical pulpotomy, Fishman et al. [10] compared the clinical and radiographic success rates between

Fig. 3. Immediate postoperative (a) and 6-month postoperative (b) radiographs of a formocresol pulpotomized tooth (mandibular right first primary molar) that was normal at the last observation. The pulpotomy was performed at age 53 months and the postoperative radiograph was taken at age 59 months.

two different pulpotomy covering medicaments, zinc-oxide eugenol (ZOE) and calcium hydroxide (CaOH). Clinical success rates of 77 and 81%, and radiographic success rates of 55 and 57% were demonstrated for the ZOE and CaOH, respectively. Compared with an earlier retrospective study [9] and the present study, their success rate is low. Fishman et al. [10] concluded that it would be premature to recommend use of the electrosurgical pulpotomy technique. This conclusion may be inappropriate as the investigation was specifically designed to compare two different pulpotomy covering medicaments following electrosurgical pulpotomies, not the success rate of the electrosurgical pulpotomy vs. the formocresol pulpotomy. The results of our study indicate that the electrosurgical pulpotomy appears comparable to the formocresol pulpotomy for human primary molars for a postoperative period of at least 5 months. The electrosurgical pulpotomy has gained popularity due to its nonpharmacological nature, ease in

Pulpotomy procedures in children

Fig. 4. Pre-operative (a) and 6-month postoperative (b) radiographs of a formocresol pulpotomized tooth (mandibular right first primary molar) demonstrating furcal pathology.

use, and favourable results. The results of our study are comparable to others reported in the literature concerning electrosurgical and formocresol pulpotomies [9,11–14] and support the hypothesis that the success rate of the electrosurgical pulpotomy is comparable to the formocresol pulpotomy. Although the electrosurgical pulpotomy is a nonpharmacological technique that produces favourable results, it is still a preservative technique. Future studies should investigate agents that leave the radicular pulp healthy and enclosed within an odontoblast-lined dentin chamber, although success may also be dependent upon an adequate coronal seal and correct choice of teeth as candidates for vital pulp therapy [15]. Conclusions The clinical and radiographic success rates for the electrosurgical group were 96 and 84%, respectively; and for the formocresol group, 100 and 92%,

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Fig. 5. Tooth (maxillary left second primary molar) with distal root resorption due to ectopic eruption of the maxillary first permanent molar (pre- (a) and postoperative (b) radiographs).

respectively. There was no statistically significant difference between the electrosurgical and formocresol pulpotomy clinical and radiographic success rates at the P < 0·05 level, thus allowing acceptance of the null hypothesis. Acknowledgements This study was supported by Birtcher Medical Services, Inc. Résumé. Objectifs. Bien que de précédentes études aient examiné la technique de pulpotomie électrochirurgicale pour les dents temporaires, aucun essai clinique bien contrôlé, chez l’homme, n’a été publié. La présente étude a eu pour propos de comparer de façon prospective les pulpotomies électrochirurgicales et les pulpotomies au formocrésol dans les molaires temporaires humaines vitales. Protocole. Cinquante enfants ont été répartis au hasard en deux groupes, 25 bénéficiant d’une

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pulpotomie électrochirurgicale et 25 d’une pulpotomie au formocrésol. Résultats. Après une période d’observation d’au moins cinq mois post-intervention, les taux de succès radiograhique et clinique pour le groupe électrochirurgical étaient de 96 et 84 pour cent respectivement, et pour le groupe formocrésol, 100 et 92 pour cent respectivement. Conclusions. Il n’y avait pas de différence statistique dans les taux de succès entre les deux groupes au niveau p < 0,05 selon le test exact de Fisher. Cette étude n’a pas démontré de différence dans le taux de succès entre techniques de pulpotomie électrochirurgicale et de pulpotomie au formocrésol.

Resultados. Al cabo de por lo menos 5 meses de observación postroperatoria, los porcentajes de éxito clínico y radiológico del grupo electroquirúrgico fueron del 96 y 84% respectivamente; mientras que del grupo de formocresol fueron del 100 y 92% respectivamente. Conclusión. No hubo diferencias estadísticamente significativas entre los porcentajes de éxito en ambos grupos a un nivel de p < 0,05 probado con el test de Exactitud de Fisher. Este estudio no pudo demostrar una diferencia en el porcentaje de éxitos entre las técnicas de pulpotomía electroquirúrgica y con formocresol. References

Zusammenfassung. Ziele. Auch wenn frühere Studien die elektrochirurgische Pulpotomie bei Milchzähnen untersucht haben, gibt es keine publizierten kontrollierten klinischen Studien. Ziel dieser Studie war es, prospektiv die elektrochirurgische Pulpotomie mit der FormokresolPulpotomie an menschlichen Milchzähnen zu vergleichen. Studiendesign. Fünfzig Kinder wurden zufällig in zwei Gruppen eingeteilt, 25 erhielten eine elektrochirurgische Pulpotomie, 25 eine FormokresolPulpotomie. Ergebnisse. Nach mindestens fünf Monaten Nachbeobachtungszeit wurde der klinische und röntgenologische Erfolg mit 96% und 84% für die ElektrochirurgieFgruppe ermittelt. Für die Formokresolgruppe lagen die Werte bei 100% und 92%. Schlussfolgerungen. Es ergab sich bei Anwendung eines Fisher-Testes keine statistisch signifikante Differenz zwischen den Erfolgsraten für die beiden Gruppen (p > 0.05). Diese Studie konnte keine Unterschiede der Erfolgsraten zwischen elektrochirurgischer Pulpotomie und der Formokresol-Pulpotomie zeigen. Resumen. Objetivos. A pesar de que estudios previos han evaluado la técnica de pulpotomía electroquirúrgica en dientes temporales, no se han publicado pruebas clínicas bien controladas en humanos. El objetivo de este estudio fue comparar de forma prospectiva, pulpotomías electroquirúrgicas versus pulpotomías con formocresol en molares temporales vitales. Diseño. Se dividieron al azar 50 niños en dos grupos; 25 recibieron pulpotomías electroquirúrgicas y los otros 25 pulpotomías con formocresol.

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