SCIENTIFIC ARTICLES

A s i m p l i f i e d m e t h o d of t r e a t m e n t for e n d o d o n t i c p e r f o r a t i o n s

William E. Ha~,is, DDS, Atlanta

A m e t h o d for s e a l i n g e n d o d o n t i c p e r f o r a t i o n s with Cavit, from a n i n t r a c o r o n a l a p p r o a c h , is pres e n t e d . R e s p o n s e to r e c a l l of the 245 p a t i e n t s w h o w e r e t r e a t e d in this m a n n e r w a s 75%, a n d the l e n g t h of time the p a t i e n t s w e r e o b s e r v e d after t r e a t m e n t v a r i e d from six m o n t h s to o v e r t e n y e a r s .

Perforations can occur as a result of misdirecting files, reamers, or burs. Perforations from root canal instruments usually can be avoided by obtaining adequate access to the root canal, by bending the instruments to conform to canal curvature before inserting them, and by not advancing to a larger-size instrument until the instrument being used has thoroughly smoothed the canal wails and is loose in the canal. Perforations from files and reamers occur most frequently near the apex of the tooth and can usually be eliminated by apicoectomy and root-end filling.1-3 Perforations from burs can occur while making post and pin preparations or while searching for a root canal. When teeth are being prepared for posts, perforations usually can be avoided by preparing the space for the post with files or

126

reamers, using a solvent, rather than with burs. 4,5 When preparations are made for pins, perforations usually can be avoided by taking care to drill only in the direction of the long axis of the tooth. One also should avoid placing pin holes in a bifurcation, in the center of a proximo-occlusal gingival step,6 or very near the pulp chamber or the periphery of a tooth. When teeth with small root canals or calcified pulp chambers are encountered, serial radiographs may be taken as access preparation progresses into the dentin while seeking the root canal. In this way, the dentist can check on where he has drilled and can make any changes of direction necessary to avoid perforation. However, one must bear in mind the obvious limitation of the radiograph, which shows only the mesiodistal and not the buccolingual direction the bur

has taken. Although care has been taken during root canal preparation, perforations have occurred, and some have been difficult to treat effectively. Some dentists in this area have believed that perforated teeth had to be extracted, or at least the perforated root of a multirooted tooth had to be amputated. As a matter of fact, before observing the degree of clinical success of the method for filling endodontic perforations reported in this paper, same patients were referred for extractions when perforations were discovered. Other patients were treated by root amputation, root separation, or intentional replantation. Some perforations that were surgically accessible were exposed by incision and flap reflection, and filled with amalgam. 1-4,6-10 However, there have been instances where the perforations were not surgically accessible, but the patient was strongly motivated to retain a tooth. In those instances, either a compromise in the prognosis had to be accepted by the patient or the tooth had to be removed, the perforation and root canal(s) filled, and the tooth replanted, or the perforated root or entire tooth had to be removed. The former was unfortunate for a compromise in prognosis required the patient to accept the risk that endodontjc treatment was done in vain if the tooth was ultimately lost because of inability to seal the perforation. Cathey '1 said that an uncorrected perforation will usually lead to extraction. Intentional replantation of a tooth carried with it certain risks: the tooth might be broken during extraction; reattachment might not take place; a chronic periodontal pocket might develop; and root resorption usually occurred and contributed to the premature loss of the tooth. Extraction was also unfortunate under any circumstances, but especial-

JOURNAL OF ENDODONTICS [ VOL 2, NO 5, MAY 1976

ly so with perforations because the causation was iatrogenic. Therefore, a better, and if possible, easier method for sealing endodontic perforations has been needed. Cavit* has been found to serve this purpose satisfactorily, with clinical success, in a large number of patients for over 14 years. The perforations filled by use of the method reported in this paper were almost all made by burs, while the practitioner attempted to locate root canals.

CAVIT AND ITS USES Cavit is a premixed polyvinyl paste that does not contain eugenol) 2 Parris and Kapsimalis, 18 and Parris and others 14 reported that Cavit produced a seal superior to zinc oxideeugenol cement, zinc phosphate cement, gutta-percha, or temporary stopping, and equal to amalgam. Widerman, Eames, and Serene ~5 found that Cavit produced a good seal when it was placed in cavities, and that it might be useful as an insulating base. N o r d , 16 in a study of 354 teeth treated by root-end fillings with Cavit, reported complete healing of bone and reestablishment of the periodontal space in 61% of the patients treated. He found that resorption of these Cavit root-end fillings was negligible because only eight of the 354 (2.26%) were affected. McGivern ~7 reported clinical success in 50 cases of root-end fillings with Cavit that were observed for two years after insertion. H e noted that no foreign body reaction occurred and concluded that Cavit was superior to amalgam as a root-end filling material because he believed Cavit was bacteriostatic and easier to place than amalgam. However, Persson, Lennartson, and Lundstr~Sm, ~s in a study of 220 teeth treated by root-end fillings with Cavit and amalgam, concluded that the results were better with amalgam than with Cavit.

They presumed, therefore, that amalgam obliterated the cavities better than Cavit. Wallentine 10 reported a better adaptation of Cavit to root canal walls than that of gutta-percha and cement sealer when Cavit was used to fill the root canals in 30 extracted teeth. Wallentine 2o also reported clinical success after the use of Cavit as a root canal filling material in an unspecified number of teeth treated in his practice. However, Flanders and others, zx in a study whereby Cavit and amalgam were implanted in the subcutaneous tissues of rats, found that Cavit produced much more irritation than did amalgam. They recommended that amalgam continue to be used for root-end fillings rather than Cavit, despite Cavit's ease of manipulation, and they questioned the use of Cavit as a root canal filling material. However, with root-end fillings, only a small part of the surface of the filling--not the entire m a s s - - i s exposed to the periodontal tissues. The irritating potential of any filling material, therefore, would likely be reduced proportionally when it is used as a root-end filling as compared with the same amount when it is implanted in the periodontal tissues as was done in Flanders' study. 21

EXPERIMENTALLY PRODUCED ROOT PERFORATIONS The histologic response of the periodontal tissues and supporting bone adjacent to experimentally produced root perforations has been investigated extensively. 22-3~ Some of the perforations in these studies were f i l l e d - - s o m e immediately, others late r - w h i l e others were left unfilled for varying lengths of time. A variety of materials was used to fill the perforations. The findings of these investigators 22-3~ w e r e generally in agreement on several points: the tissues adjacent

to a perforation could heal; the repair potential was better when a perforation was filled rather than left unfilled; and the sooner a perforation was filled the better the chance for the underlying tissues to heal. However, with perforations proximal to the gingival sulcus there was a greater risk that a chronic periodontal pocket would develop than with the more apically situated perforations.

ENDODONTIC PERFORATIONS FILLED BY OTHER INVESTIGATORS Nicholls 1 reported 29 cases of root perforations in humans in which the perforations were filled with zinc oxide-eugenol paste when they were not surgically accessible, or with amalgam when surgically accessible. He formulated a classification of endodontic perforations but did not indicate whether the treatment for the perforations was successful or not. Str6mberg, Hasselgren, and Bergstedt 31 presented a classification of endodontic perforations, and reported 24 cases of root perforations in humans in which the perforations were filled with a mixture of gutta-percha, resin, and chloroform. The patients wer6 followed from one to eight years after treatment; 18 treatments were considered successful, two failures, and four uncertain. Grossman 7 recommended that the root canal in a perforated tooth be filled in the usual manner, but with an excess of cement sealer to force the sealer into the perforation during the filling of the root canal. Taatz and Stiefel9 recommended filling surgically accessible perforations with amalgam. F o r others they recommended filling the perforation with calcium hydroxide, followed by root canal filling. Cathey 1~ recommended that perforations be filled first by a layer of calcium hydroxide, then by a layer of Kloroperka N/O, and then

127

JOURNAL OF ENDODONTICS I VOI. 2, NO 5, MAY 1976

by amalgam or gutta-percha. Frank and Weine '~2 recommended that perforated resorptive defects be filled with calcium hydroxide until the adjacent lesion remineralized. The root canals then were filled in the conventional manner using the newly remineralized bone adjacent to the perforation as a matrix against which the root canal filling material was condensed. ENDODONTIC PERFORATIONS FILLED W I T H CAVIT Cavit can be used to fill endodontic perforations satisfactorily, and it can be placed from within the root canal or the pulp chamber. This obviates the necessity for surgery to expose the perforation for external repair with an amalgam filling, or for subjecting the patient to root amputation or intentional replantation. Other cements might be found that also will serve this purpose as well, but Cavit is preferred because it has been shown that it produces a good seal and is easy to manipulate.13-17,ra.2o The technique using Cavit is quite simple and can be done quickly. When a perforation is discovered, the root canal and pulp chamber are debrided, irrigated, and dried. The perforation is gently blotted with absorbent cotton to control the hemorrhage that usually occurs and to dry the site. A small sphere of Cavit is placed in the perforation and gently patted into place, using a pledget of cotton with minimal pressure. More Cavit is added until the perforation is filled, and the adjacent area is built back to its original level. Care is taken to fill the perforation completely but not to push any of the Cavit out of the tooth into the periodontal space. (Excess Cavit was seen infrequently; however, in a few instances some material was inadvertently pushed out into the periodontal tissues. When the amount of 128

excess was small, no special treatment was instituted and the excess appeared on the recall radiograph to be tolerated by the patients satisfactorily. However, when the amount of excess was large, surgical intervention was required to recover the excess Cavit and to contour the Cavit remaining in the perforative defect to the morphologic structure of the tooth, s'~ Figure 1 shows a case in which the amount of the excess was not large and was well tolerated by the patient, with healing of an adjacent lesion and an indication of some resorption of the excess Cavit. Figure 2 shows a case in which the amount of excess was large and had to be recovered surgically.) The root canal again is irrigated and dried, and medication is sealed in the pulp chamber. No filing is done near the perforation during this visit to avoid disturbing the still-soft Cavit, but filing usually is done in the other canals. (In the earlier cases, it was decided to do no filing on the first visit to determine what postoperative symptoms the perforations and their fillings might produce. If filing had been done during the same visit, and pain or other symptoms developed afterward, a determination could not have been made whether the symptoms are attributable to the perforation and its filling only, to the manipulation and resultant periapical inflammation caused by the filing, or to a combination of both procedures.) On the next visit, the Cavit seal is hard and endod'ontic treatment proceeds as if the perforation has not occurred. Cavit remains in place well, and is not dislodged when abraded with files and reamers during canal preparation or during the procedures when the canal is filled. D I S C O V E R Y C A S E REPORT The patient, a 2V-year-old white

Fig 1--Series o/ radiographs shows: tooth initially (top); per/oration filled with Cavit and root canals filled (center); at three years, adjacent lesion has healed and some resorption of excess Cavit has occurred (bottom). woman, had a mandibular left first molar that had been perforated by a bur, while the practitioner attempted to locate the distal root canal. The perforation was at the mesial side of the distal root near the bifurcation. The initial radiograph showed a radiolucent lesion at the apex of the mesial root, and an area of bone loss between the roots of this tooth (Fig 3, top left). The patient was advised on her first visit, as was my custom then, that a surgical procedure would be

JOURNAL OF ENDODONTIC$ ] VOL 2, NO 5, MAY 1976

Fig 2--Series of radiographs shows: tooth initially (top left); perforation filled with Cavit (top center); root canals filled (top right); excess Cavit has been removed (bottom left); at six months, septal bone has almost completely regenerated (bottom center); at 18 months, level of septal bone has been maintained (bottom right).

required to seal the perforation with amalgam after the endodontic treatment was completed. The perforation was filled with Cavit (Fig 3, top center), with the thought that Cavit would provide a good seal during endodontic treatment and that the pink color of Cavit would contrast well with the white color of the tooth, thereby making it easier to see the full extent of the perforation during surgery. Endodontic treatment was completed in three visits over a period of 32 days (Fig 3, top right), and the patient was appointed for surgery. However, she cancelled this surgery appointment and several others so that eight months had passed before she was seen again. A radiograph (Fig 3, bottom left) indicated that the lesions had healed. Because radiographic findings indicated, that the Cavit seal was intact and the lesions had healed, it was decided to defer surgery. The patient

was asked to return in six months for reexamination. She did not return when requested, but was seen four years and ten months later. Her tooth had continued to remain comfortable. A radiograph (Fig 3, bottom right) indicated that the radiolucent areas, which had healed during the first eight months after treatment, appeared normal four years and ten months later. The interradicular bone had regenerated well and remained stable, even directly adjacent to the perforation, and the Cavit seal appeared on the radiograph to be intact and unchanged since it had been placed. The patient was dismissed as not needing an additional treatment for the root perforation. This method for filling endodontic perforations has been used for over 14 years, in 245 cases, with clinically satisfactory results. As far as it can be determined, only four of these teeth were extracted, and one was subjected to hemisection. One tooth was diagnosed

as split and was extracted eight months after treatment. A second tooth was extracted 14 months after treatment when a large amalgam restoration collapsed, and the tooth was diagnosed as nonrestorable. Another tooth was removed 26 months after treatment for an undeterminable reason. The fourth tooth was extracted eight years after treatment when pain occurred. The tooth that was hemisected was so treated five months after endodontic treatment. The patient was asymptomatic, but the referring dentist requested that the perforated root be removed before he constructed an extensive fixed prosthesis in the area.

STATISTICAL SUMMARYm PERFORATIONS FILLED WITH CAVIT During the 14-year period from August 1961 through July 1975, 322 instances of endodontic perforations have been seen. Of these, 180

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JOURNAL OF ENDODONTICS [ VOL 2, NO 5, MAY 1976

Fig 3----Series of radiographs shows: tooth initially (top left); perforation filled with Cavit (top center); root canals filled (top right); at eight months, lesions have healed (bottom left); at four years and ten months, normal bone pattern has been maintained (bottom right).

(55.9%) were in the teeth of women, while 142 (44.1%) were in the teeth of men. The ages of the patients, the numbers of perforations in each age group, the distribution of perforations by tooth involved, and the numbers of perforations seen by year of occurrence are shown in Tables 1, 2, and 3. Two hundred forty-five teeth were filled with Cavit in the manner described in this paper. Two hundred and twelve of the 245 teeth were treated six months ago, or longer, and were available for recall examinations. One hundred fifty-nine patients (75%) responded to recall and were examined. Most patients (72.95%) were seen for a single recall examination, but some were seen for as many as five recall examinations. The length of time the patients were observed after treatment and the number of patients that responded at each time interval are shown in Table 4.

Lesions A summary of the response of the lesions after endodontic treatment was made to determine if the additional

130

trauma of perforation and filling of the perforation had any adverse effect on the rate of healing of the lesions. The lesions were mostly periapical, with a few occurring in the intraradicular area of molars and a few occurring laterally. The distribution was what one might expect to find in any large group of consecutive endodontic patients. The response of the lesions to treatment is presented in Table 5. The total favorable response was 87.42%. This compares favorably with the response of lesions to treatment in the total group of patients with nonperforated teeth. It was concluded, therefore, that the trauma and presence of perforations filled with Cavit did not inhibit the healing of lesions in the patients reported here.

Lesions Adjacent to Perforations A summary was made concerning lesions that were adjacent to the site of perforations, or that developed there later. This summary was made to determine if lesions initially present at the site of a perforation would heal, and if the formation of a lesion

at that site (if none were present initially) could be expected after endodontic treatment and the filling of the perforations with Cavit. The response of lesions adjacent to perforations is presented in Table 6. The total favorable response was 89.31%. This compared favorably with the response of lesions of the teeth in the total group of patients with nonperforated teeth. The findings of this summary indicate that the chance of a lesion developing at the site of a perforation that had been filled with Cavit, plus the failure of a lesion to heal that preexisted at the site of a perforation filled with Cavit, was only about one in ten. It was concluded, therefore, that the presence of a perforation filled with Cavit did not inhibit the healing of lesions at the site of a perforation, nor was there significant likelihood of a lesion developing adjacent to a perforation filled with Cavit when no lesion was present there initially. DISCUSSION While this report is that of clinical

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observations made of patients treated in a private endodontic practice, and has no histologic evidence in direct support of the findings presented, it is believed that the work of the other investigators9,x6,2~-a~ lends histologic credence to this report. Each of the patients reported here was managed in the manner that the aforementioned investigators found to be the most conducive to the healing of tissues adjacent to perforations in teeth: each perforation was filled, was filled promptly, and was filled with a substance shown to produce a good seal. The patients whose teeth were perforated at or near the level of the attached gingiva were not treated in this manner. They were either referred for extraction, or their perforations were filled with amalgam placed from an external approach after gingival recontouring. The tooth in the discovery case has ftmctioned comfortably and without symptoms for over 14 years since treatment. Most of the other teeth that were treated and reexamined have functioned satisfactorily with clinical success for various periods of time up to as long as 14 years. A general increase in the number of perforations seen year by year was noticed (Table 3). It is believed that this increase did not indicate that more accidents were occurring, but instead denoted a change in the attitude of the referring dentists. It is believed that these dentists were referring more patients with perforated teeth for endodontic treatment rather than for extraction. Another factor that might account for this general yearly increase in the incidence of perforations might be that a greater number of older patients, in whose teeth the root canals are usually much smaller and therefore more likely to be subject to perforations, were being seen each year than in previous years. This could have been caused by the

t VOL 2, N O 5, M A Y 1976

Table 4 9 Length of time patients w e r e f o l l o w e d a n d n u m b e r of patients res p e n d i n g at e a c h t i m e interval.

Follow-up period 6 mo 7-12 mo 13-18 mo 19-24 mo 25-36 mo 37-48 mo 49-60 mo ,Over 5 yr Over I0 yr

No. of .pa,tients responding 57 54 12 13 19 9 2 13 4

(31.15%) (29.51%) (6.56%) (7.1(/%) (I0.38%) (4.92%) (1.09%) (7.10%) (2.18%)

Table $ 9 R e s p o n s e of all l e s i o n s : to treatment.

Type of .response at: recall No lesion initially None developed Lesion initially Healed or smaller

No. of lesions 77 (48.43%) 62 (38.99%)

T a b l e 6 9 R e s p o n s e of l e s i o n s at site of pertorafion to treatment.

No change in size

6 (3.77%)

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JOURNAL OF ENDODONTICS [ VOL 2, NO 5, MAY 1976

increased life span of patients, noticed generally in recent years, resulting in a greater number of older patients being available for treatment; the increased motivation of older patients to retain their teeth, which has been noticed in this area during the last two decades, especially during the last decade; or a combination of both factors. Care should be taken to avoid perforating teeth during endodontic treatment because a perforation necessitates additional treatment not needed by the patient initially. However, once a perforation has been made, the tooth need not necessarily be extracted or subjected to root surgery or intentional replantation because of the perforation. The findings of the cases reported here indicate that an assumption need not be made that a perforated tooth, treated in the manner described here, cannot function as well as before the perforation occurred. Futhermore, such a tooth will not necessarily be lost prematurely because of the perforation. The traditional method of filling root perforations with amalgam, after the site of the perforation has been surgically exposed, can be done for those teeth where the perforation is

surgically accessible should the need arise, or should the dentist prefer this method of treatment initially. However, for those patients whose perforations are not surgically accessible, it is believed that the method described here is much preferred to the only other method of filling such perforations--intentional replantation. It also is believed that this method of treatment could well be the treatment of choice for selected surgically accessible endodontic perforations as well. It is hoped that this paper will stimulate an investigation and a published report of the histologic response of tissues adjacent to root perforations that have been filled with Cavit, and that other dentists will consider using this method to treat perforations in their practices in preferance to more-involved treatment procedures or the extraction of teeth. SUMMARY

Endodontic perforations have occurred even though care is taken when filing and drilling. In the past, such teeth have been extracted or subjected to root amputation, root separation, intentional replantation, or externally placed amalgam fillings af-

Table 7 9 Comparison of findineJs of author and five reviewinq dentists reqardinq response of all lesions to treatment.

No. of lesions Type of response at recall No lesion initially None developed Lesion initially Healed or smaller Lesion initially Enlarged No lesion initially One developed Lesion initially No change in size 132

Author's findings

ter the gingiva over the perforation had been surgically reflected. A nonsurgical method for sealing endodontic perforations with Cavit, from an intracoronal approach, has been presented. From a total of 322 perforations seen over a 14-year period, 245 were treated by filling with Cavit, followed by root canal filling, and 75% of the patients were seen on recall examinations varying from six months to over ten years after treatment. Clinical experience has indicated that these Cavit seals appear to be permanent and are well tolerated by the patients. Most of the teeth have continued to function satisfactorily without the development of symptoms attributable to the perforations or their filling with Cavit. ADDENDUM--INTERPRETATION OF RADIOGRAPHS

The reporting of the categories of statistical data presented, except for one, was simply that of summarizing information obtained from the patients' records. The response of lesions to treatment, however, involved individual judgment in radiographic interpretation. An attempt was made to evaluate the radiographs critically and objectively, but it was realized

Table 8 9 Comparison of findinqs of author and live reviewinq dentists recJardineJ response of lesions located at site of perforations to treatment.

Reviewing dentists' findings A B C D E

77

107

53

63

43

25

62

43

81

77

86

81

8

0

16

6

8

23

7

6

7

8

9

0

5

3

2

5

13

30

No. of lesions Type of response at recall No lesion initially None developed Lesion initially Healed or smaller No lesion initially One developed Lesion initially No change in size

Author's findings

Reviewing dentists' findings A B C D E

122

127

125

129

119

122

20

25

28

23

22

21

I1

6

4

5

10

9

6

1

2

2

8

7

JOURNAL OF ENDODONTICS 1 VOL 2, NO 5, MAY 1976

Table 9 9 Comparison of favorable response percentages of all lesions to treatment, according to author and five reviewing dentists,

Table 10 9 Comparison of favorable response percentages of lesions at site of perforations to treatment, according to author and five reviewing dentists.

Favorable response % Author Reviewing dentists A B C D E

87.42 94.34 84.28 88.05 81.13 66.67

that the possibility of personal bias, however unintentional, might have influenced my judgment. Therefore, five other dentists were asked to evaluate the radiographs: a chairman of basic dental sciences, a chairman of endodontics, a board-certified periodontist in private practice, a boardcertified endodontist in private practice who is also a part-time teacher, and a general dentist in private practice. Each dentist was asked to evaluate 159 sets of radiographs--one set for each patient who responded to recall - - a n d to classify each set in one of five categories. Each set consisted of the original posttreatment radiograph to be compared with the latest followup radiograph. None of the five dentists knew my findings or each other's findings until all had recorded their evaluations. Therefore, it is believed that the review was conducted on an intellectually honest basis, and although perhaps not on as unbiased a basis as possible, certainly as unbiased as practical for the purposes of this study. Two evaluations were recorded: one of the lesions in general and the other of the lesions at the site of the perforations. The findings of the five reviewing dentists, as compared with mine, are shown in Tables 7 and 8. A comparison of the favorable responses as found by the reviewing

Favorable response % Author Reviewing dentists A B C D E

89.31 95.60 96.23 95.60 88.68 89.94

dentists is shown in Tables 9 and 10. While the comparisons shown in these tables indicate that the six reviewers saw the radiographs differently, the percentages are very close and the findings are, therefore, similar. It is believed that the initial impression - - t h a t the radiographs had been reviewed on a critical and objective basis--was correct. *Premier Dental Products Co., Philadelphia. The author thanks Drs. William M. Davis, Emile T. Fisher, John M. Itartness, Parker E. Mahan, and Thomas W. McDonald for their help in reviewing the radiographs 'of the cases reported in this paper. A preliminary report on this method was given before the Tar Heel Endodontic Association in Chapel Hill, NC, Nov 16, 1974. This paper was presented before the Georgia Association of Endodontists in Atlanta, Nov 9, 1975. Dr. Harris is in private practice limited to endodontics. He is a clinical associate in endodontics at Emory University School of Dentistry in Atlanta, ,on the teaching staff in clinical endodontics at the Medical College of Georgia School of Dentistry in Augusta, and chief of endodontic services and a mem'ber of the executive committee at Massell Dental Clinic in Atlanta. Requests for reprints should be directed to Dr. William E. Harris, 401 Peachtree St NE, Atlanta, 30308.

References

1. Nicholls, E. Treatment of traumatic perforations of the pulp cavity. Oral Surg 15:603 May 1962. 2. Leubke, R.G.; Glick, D.H.; a n d Ingle, J.I. Indications and contraindications for endodontic surgery. Oral Surg 18:97 July 1964. 3. Messing, J.J. The use of amalgam in endodontic surgery. J Br Endod Soc 1:34 Autumn 1967. 4. Riggans, J.W., Jr. The case history of a root perforation and a method for its prevention. Dent Dig 77:275 May 1971. 5. Neagley, R.L. The effect of dowel preparation on the apical seal of endodontically treated teeth. Oral Surg 28:739 Nov 1969. 6. Harris, W.E. Pseudoendodontic sinus tract: report of case. JADA 83:165 July 1971. 7. Grossman, L.I. The management of accidents encountered in endodontic practice. D Clin North Am 11:903 Nov 1957. 8. Leubke, R.G., and Dow, P.R. Correction of an endodontic root perforation. Report of a case. Oral Surg 17:98 Jan 1964. 9. Taatz, H., and Stiefel, A. Zur therapie von zahnperforationen. Zahniierztl Welt 66:814 Nov 1965. 10. Weissman, M.I. Unique sealing of an internal resorptive lesion of the bifurcation. J Ga Dent Assoc 43:26 Spring 1970. 11. Cathey, G.M. Molar endodontics. D C.lin North Am 18:356 April 1974. 12. Premier Dental Products Company. Instruction insert for Cavit package. Philadelphia, 1969. 13. Parris, L., and Kapsimalis, P. The effect of temperature change on the sealing properties of temporary filling materials (part 1). Oral Surg 13:982 Aug 1960. 14. Parris, L.; Kapsimalis, P.; Cobe, H.H.; and Evans, R. The effect of temperature change on the seating properties of temporary filling materials (part 2). Oral Surg 17:771 June 1964. 15. Widerman, F.H.; Eames, W.B.; and Serene, T.P. The physical and biologic properties of Cavit. JADA 82:378 Feb 1971. 16. Nord, P.G. Retrograde rootfilling with Cavit: a clinical and roentgenological study. Sven Tandlak Tidsk:r 63:261 April 1970. 17. McGivern, B.F. Temporary filling favored over alloy in retrograde root 133

JOURNAL OF ENDODONTICS [ VOL 2, NO 5, MAY 1976

therapy. Clin Dent 2:5 April 1974. 18. Persson, G.; Lennartson, B.; and Lundstr/Sm, I. Results of retrograde rootfilling with special reference to amalgam and Cavit| as root-filling materials. Sven Tandlak Tidskr 68:123 May 1974. 19. Wallentine, R. An in-vitro evaluation of Cavit as a root canal filling material, thesis. University of Southern California, Los Angeles, 1972. 20. Wallentine, R. Cavit as root canal filling material. Read before the American Association of Endodontists, San Diego, Calif, April 18, 1974. 21. Flanders, D.H.; James, G.A.; Burch, B.; and Dockum, N. Comparative histopathologic study of zincfree amalgam and Cavit in connective tissue of the rat. J Endod 1:56 Feb 1975. 22. Euler, H. Perforation und parodontium. Dtsch Mon atsschr Zahnheilkd 43:801, 1925. 23. Kubler, A. Heilungsvorgiinge nach

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wurzelperforationen. Schweiz Monatsschr Zahnheilkd 44:413, 1934. 24. Ruchenstein, H. Les perforations radiculaires trait6es au Calxyl, Schweiz Monatsschr Zahuheilkd 51:685, 1941. 25. Kaufmann, J. Untersuchungen am paradentium der traumatisch perforierten zahnwurzel. Schweiz Monatsschr Zahnheilkd 54:387, 1944. 26. Lange, G. Artificielle perforation des wurzelkanales und deren behandlung. Dtsch Zahnherztl Z 6:299 March 15, 1958. 27. Lantz, B., and Persson, P.A. Experimental root perforation in dogs' teeth. A roentgen study. Odontol Revy 16:238, 1965. 28. Lantz, B., and Persson, P.A. Periodontal tissue reactions after root perforations in dogs' teeth. A histologic study. Odontol T 75:209 June 1967. 29. Lantz, B., and Persson, P.A. Periodontal tissue reactions after surgical

treatment of root perforations in dogs' teeth. A histologic study. Odontol Revy 21:51, 1970. 30. Seltzer, S.; Sinai, I.; and August, D. Periodontal effeots of root perforations before and during endodontic procedures. J Dent Res 49:332 MarchApril 1970. 31. Str6mberg, T.; Hasselgren, G.; and Bergstedt, H. Endodontic treatment of traumatic root perforations in man. A clinical and roentgenological followup study. Sven Tandlak Tidskr 65:457 Sept 1972. 32. Frank, A.L., and Weine, F.S. Nonsurgical therapy for the perforative defect of internal resorption. JADA 87:863 Oct 1973. 33. Harris, W.E., and Davis, J.E. Repair of a perforation in the bifurcation of a mandibular molar. Report of a case. J Ga Dent Assoc 49:16 Autumn 1975.

A simplified method of treatment for endodontic perforations.

SCIENTIFIC ARTICLES A s i m p l i f i e d m e t h o d of t r e a t m e n t for e n d o d o n t i c p e r f o r a t i o n s William E. Ha~,is, DDS, A...
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