0099-2399]89]1506-0267/$02.00/0 JOURNAL OF ENDODONTICS Copyright �9 1989 by The American Association of Endodontists

CASE REPORTS

Printed in U.S.A. VOL. 15, No. 6, JUNE 1989

Conservative Treatment of Root Perforations Using Apex Locator and Thermatic Compactor--Case Study of a New Method

Arieh Y. Kaufman, DMD, and Senia Keila, DMD

Endodontic perforation, a serious complication in dental practice, is among the most common prob- lems associated with endodontic procedures. Rec- ommended methods of treatment are surgical or conservative using calcium hydroxide paste. A method in which perforations can be obturated im- mediately after their detection is described. The method utilizes an apex Iocator for measurement and detection of the perforation and a two-step treatment of thermatic compaction for filling the root canal as well as the perforation. A number of cases with a long follow-up are presented.

An endodontic perforation is defined as an artificial opening in the crown or in the root of a tooth, resulting in a commu- nication between the pulp chamber or the root canal of the tooth and the periodontal attachment apparatus (1, 2). Idi- opathic resorptions and iatrogenic perforations produced dur- ing endodontic or prosthetic manipulations are the two major causes of perforations.

Seltzer et al. (3) report that the repair of periodontal injury caused by perforations is related to its location and the time lapse between the perforation and its closure. Stromberg et al. (4) propose the following classification of root perforation areas which are usually found in four sites along the tooth: (a) the coronal portion of the root under the marginal bone level; (b) the furcation area and 2 mm apically; (c) the middle Portion of the root; and (d) the apical portion of the root. The type of therapy is indicated by the location of the Perforation:

1. Apicoectomy, root amputation, or hemisection, if the perforation is near the apex of the root where amalgam filling is not feasible;

2. Surgical approach and amalgam filling of perforations in the middle third of the root canal;

3. Perforations in the coronal third of the root or in the floor of the pulp chamber are treated with different methods and different materials (1, 5-9).

Most techniques for correcting perforative defects reported in the early 1960's and 1970's require surgical intervention. Since surgical procedure can cause damage to the periradi- cular tissue and possible extensive bone defects, any successful treatment avoiding surgical intervention is preferable.

Sunada in 1962 (10) introduced an electronic measuring device to locate the apical foramen. This method has gained great popularity and has been shown to be reliable (11-13). In 1976 the potential use of the Sono-Explorer as a device for locating, detecting, and correcting root perforations was first reported (14). Moreover, in 1983 the use of an apex locator as an aid for detecting perforations was suggested (15). Both articles consider the possibility of changing the surgical ap- proach into a more conservative one by using apex locators. The method, which describes correcting perforations with the

FIG 1. Clinical appearance of the perforation (arrow).

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268 Kaufman and Keila Journal of Endodontics

FiG 2. A, Measuring and detecting the perforation using an apex Iocator. B, Radiograph confirming the suspicion of the perforation site using an apex Iocator.

FIG 3. Fitted master cone, 2 mm short of the perforation site.

A

FIG 5. A, The gutta-percha after obturation. Note the rigid part of the gutta-percha projecting from the tooth. B, Radiograph of the root canal filling after removing the coronal gutta-percha.

FpG 6. MacSpadden compactor and gutta-percha cone fitted to OI3' turate the perforation. B, Final radiograph after obturation. C, Clinica appearance of the obturated perforation site (arrow).

B !~!~ i i ! i �84 �84184 ~ ! ~ ~ ~

FIG 4. A, Radiograph confirming the length measurement of the main root canal. B, Gutta-percha and MacSpadden compactor inserted into the main root canal.

aid of apex locators, suggests the use of the lateral condensa- tion technique (14); however, this technique is time consum- ing.

MacSpadden, in 1979, introduced the thermomechanical compaction technique for root canal fillings (16). A major advantage is that the technique is fast and the filling penetrates into accessory canals (17).

The purpose of this article is to describe a new method for treating root perforations in a conservative way, combining

Vol. 15, No. 6, June 1989 Perforation Repair 269

FIG 7. A, Diagnostic radiograph showing lateral bone destruction between teeth 29 and 30. Notice the access opening in the mesial root of tooth 30 which could lead to another root perforation. B, Final radiograph taken on completion of root canal treatment which consisted of thermomechanical obturation of the perforation site and the main canal. C, Follow-up 28 months later, indicating a full bone regeneration of the bone defect and a small widening of the periodontal ligament near the perforation site. D, A 6-yr follow-up.

the use of an apex locator and the thermatic compaction technique.

DESCRIPTION OF THE M E T H O D

When a root perforation is suspected (Fig. 1), the tooth is isolated and prepared for endodontic treatment (18). Any bleeding should be stopped with formocresol or epinephrine (1:100) at the tip of a paper point (19). Detection of the perforation is carried out with the aid of an apex locator by introducing the largest root canal file which can reach the site without completely penetrating the perforation (Fig. 2). Thus, the chance of damage to the surrounding tissues and bleeding, which may interfere with correct detection of the perforation, is eliminated. In old perforations, root canal files are intro- duced in descending order of file size to locate the perforation opening, so as to prevent bleeding and a fresh injury.

The distance to the perforation opening is measured using an apex locator. The root canal is dried with absorbent paper points and a master cone is fitted to obturate the perforation. A gutta-percha cone is selected two sizes larger than the file used for detecting the perforation. It must stop 2 mm short of the perforation opening (Fig. 3).

After cleaning and shaping the root canal, the obturation

of the main canal apical to the perforation is performed by using the thermatic condensation technique with sealer at the tip of the gutta-percha (Fig. 4). The time of compaction, usually 6 s, is prolonged to approximately 7 to 9 s without withdrawing the compactor. This permits homogenous plas- ticization of the apical gutta-percha while the coronal portion remains rigid and is later removed with tweezers (Fig. 5).

The perforation site is measured again with the aid of an apex locator to ensure its accessibility. The apical portion of the gutta-percha cone which was previously fitted to obturate the perforation is immersed in a sealer, introduced into the root canal 2 mm short of the perforation site, and followed by thermatic condensation (Fig. 6). In cases where the main root canal filling is terminated coronal to the perforation, this part of the root canal filling is removed to the perforation site and the procedure is followed as previously described.

Four cases demonstrating the efficacy of this method are presented.

CASE 1

A 38-yr-old woman was referred to the Endodontic De- partment of Yermiahu University Clinic because her dentist could not find the opening of the mesial root canal of tooth 30.

270 Kaufman and Keila

FIG 8. A, Diagnostic radiograph of tooth 27 with gutta-percha point in the pocket. B, Radiograph taken on completion of the obturation of the perforation and adaptation of the post. C, A foUow-up radio- graph 3 yr postoperative. The attachment apparatus maintains its continuity.

Clinical examination and a diagnostic radiograph revealed a lateral bone defect, 15 mm in diameter, between the distal area of tooth 29 and the lamina dura of tooth 30. There was an old root canal filling in tooth 29 and the origin of the bone defect was suspected to be a perforation in that tooth (Fig. 7A).

The confirmation of the perforation was made with the aid of an apex locator (Dentometer; Dahlin Electromedicine, Denmark). Treatment consisted of debriding and cleansing the root canal by Salvizol solution (Ravensberg GmBH, Kon- stanz, West Germany) (20, 21); Salvizol ointment (Ravens- berg GmBH, Konstanz) was introduced as intracanal medi- cation. The main canal was obturated by the lateral conden- sation technique (Fig. 7B). The perforation was obturated by the thermomechanical method 1 wk later, as previously de- scribed.

When the patient appeared for her next visit, tooth 30 was endodontically t~eated by a conventional method. Follow-up examination 28 months later revealed complete bone regen- eration of the lateral defect with a small widening of the periodontal ligament near the perforation site (Fig. 7C). Six- year follow-up showed total repair (Fig. 7D).

CASE 2

A 57-yr-old man was referred to the Endodontic Depart- ment after post preparation in tooth 27. When the post was

Journal of Endodontics

inserted, the patient felt a sharp pain; a perforation was suspected. The dowel was shortened and temporarily ce- mented. Two days later the patient returned to the clinic complaining of sharp pains and swelling in the buccal region. Antibiotic therapy (ampicillin, 2 g daily for 4 days) was administered.

Further consultation revealed no signs of an acute abscess, however, a pocket measuring 8 mm was diagnosed on the mesial side of the root. Slight tenderness was felt on palpation of the apical region. A gutta-percha point was inserted into the pocket and a radiograph was then taken which confirmed the suspected perforation (Fig. 8A).

The post was removed and a #80 file was inserted into the canal attached to an apex locator. The perforation was diag- nosed at a depth of 12 ram, located on the mesial side. Obturation was carried out by inserting a #100 gutta-percha (DeTrey Ltd., Zurich, Switzerland; Dentsply Distributor) cone which penetrated to a depth of 10 mm. The tip of the gutta-percha was then dipped in a hard calcium hydroxide base (Life; Sybron/Kerr, Romulus, MI) (22) and reinserted into the canal. With the aid ofa # 100 MacSpadden compactor (Randolf and Ranson, Caulk Dentsplay, Toledo, OH), the gutta-percha was fed into the canal at 15,000 rpm. A larger compactor, #110, was used for removing the excess filling which was marked to the length of the dowel. The post was temporarily cemented (Fig. 8B).

The patient was referred to the Periodontal Department for a pocket elimination performed immediately after conclu- sion of the endodontic treatment. Three years of postoperative follow-up was uneventful (Fig. 8 C).

CASE 3

A 30-yr-old man was seen for root canal treatment on tooth 28. The patient returned to the clinic the following day complaining of severe pain. His dentist started treatment of tooth 29 which was left open for drainage. When the severe pain continued, examination revealed that tooth 28 was tender to both vertical and horizontal percussion. A diagnostic radiograph showed that this tooth had two roots (Fig. 9A). The tooth was irrigated and dried. Working length was deter- mined by an apex locator, and a perforation was detected at a depth of 14 mm from the reference point. The buccal main canal was found, a file reinserted into the suspected perfora- tion, and a radiograph taken (Fig. 9B). The lingual canal was also found. A master cone was fitted to the perforation site. The apical third of the buccal and lingual canals was obtu- rated. The perforation and the coronal portion of the canals were then obturated as previously described. Two final radio- graphs, an orthoradial and one according to Walton's projec- tion technique, were taken (17) (Fig. 9, C and D). This case demonstrates the applicability of this method even in com- plicated cases.

CASE 4

A 26-yr-old woman was seen for swelling above the crown of tooth 9. Clinical examination and radiographs led to a diagnosis of an acute periodontal abscess caused by an iatro- genie perforation in connection with an old cemented post (Fig. 10A). The bridge was removed and the perforation was

Vol. 15, No. 6, June 1989 Perforation Repair 271

Fie 9. A, Diagnostic radiograph of teeth 28 and 29. Notice two roots in tooth 28 (arrow). B, Length measurement radiograph and detection of the perforation site. C, Orthoradial radiograph of the root canal filling of tooth 28. D, Walton's projection of the same tooth.

FiG 10. A, Diagnostic radiograph showing lateral radiolucency in tooth 9 caused by a perforation. B, A 1-yr follow-up radiograph. Notice a Small overfilling of the gutta-percha protruding into the periodontal ligament (arrow), showing advance bone regeneration.

verified by attaching the probe electrode of an apex locator to the post. The post was removed and the perforation was obturated by thermatic compaction. The master cone was coated with Life. One-year follow-up showed advanced heal- ing (Fig. 10B).

DISCUSSION

Endodontic perforation, a serious complication in dental practice (4), is among the most common problems associated with endodontic procedures (1). At one time surgical inter- vention or extraction of the tooth was the recommended treatment (17). The development of new materials and meth- ods has made it possible to save many of these teeth and treat them with a conservative technique (2, 23, 24).

Calcium hydroxide was introduced to dentistry by Herman in 1930 (25). Frank (2) and Taatz and Stiefel (26) suggested the used of calcium hydroxide for the treatment of perfora- tions; cases scheduled for surgery could be treated conserva- tively. However, placement of calcium hydroxide at the per- foration site to obtain a hard barrier is time consuming and has to be replaced frequently.

The method presented in this study enables an immediate treatment of root perforations, saving time for both the patient and the clinician. It is recommended for treating perforations along the apical, middle, or coronal third of the root. The method is simple, but every step must be followed meticu- lously. The main problem may be overfilling caused by a narrow master cone. In some cases, the master cone may be compacted through the perforation opening into the sur- rounding tissue. This may cause constant irritation, delay, or even prevention of complete healing.

272 Kaufman and Keila

In cases where bleeding is extensive and cannot be stopped, calcium hydroxide paste introduced with the aid of a Mac- Spadden compactor will solve the problem temporarily. It is not necessary to wait until a hard barrier is obtained. The final obturation can be performed a week later.

We wish to thank Mrs. R. Lazar and Mrs. D. Yellin for their editorial assistance and preparation of the manuscript.

Dr. Kaufman is in the Senior Lecturer Section of Endodontology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv Univer- sity, and is head, Endodontic Department, "Yermiahu" University Clinic, Tel Aviv, Israel. Dr. Keila is a postgraduate student, Section of Endodontotogy, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, and staff member, Endodontic Department, "Yermiahu" University Clinic, Tel Aviv.

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