Tissue reaction to root canal cements containing paraformaldehyde

Tissue reaction to root canal cements containing paraformaldehyde Two

case

studies

Peter Laband, D.M.D.,

Northampton,

Mass.

T he use of paraformaldehyde

(PFA) as a component of root canal sealers and pastes has produced a great deal of controversy. Langeland’ considered PFA to be extremely irritating; Spangberg and Langeland, in experiments on tissue cultures, showed it to be highly toxic. Bordoni and Erausquir? produced necrosis and ankylosis with chronic inflammation by its use. Engstrom and Spangberg4 found that N2 (a PFA-containing cement) produces considerable inflammation of periapical tissues when used in partial pulpectomies and found it to be significantly less successful than the control experiments. All of the above were either animal or tissue-culture studies. Orlay and Ehrman# published three cases of accidents in man with the use of N2. On the other hand, other studies have shown good results: Overdiek and Sauerwein7 obtained good clinical results and reported that the use of N2 has been taught in the Department of Conservative Dentistry of the Clinic at Bonn since 1958 and at Heidelberg since 1965. Rowe8 reported favorable results and concluded that the addition of PFA to a root canal cement produces little irritation. Snyder, Seltzer, and Moodniks (with an extensive review of the literature) found N2 well tolerated and less irritating than silvercontaining cement. Barker and Lockett lo found little inflammatory response to N2 and considered it well tolerated. Muruzabal, Erausquin, and DeVoto,” in testing ten sealers, found adverse histologic changes in all of them, with no unusually severe effects produced by the N2. Erausquin and MuruzabaP2 compared the tissue reactions to root canal fillings using ZOE, Kerr’s, Grossman’s, and N2 cements, found all of them irritating, and believed that the wide range of responses indicates that this diversity depends more on the technique used than on the choice of filling material. Friend and Browne13 investigated eleven root canal filling materials and found that N2 produced an early severe reaction with a rapid resolution of the inflammatory response, which by 4 weeks was only slight. Laband14 evaluated the effectiveness of a formalin-containing root canal cement and found it to have a useful place in endodontic treatment. Rowe15 reported on three cases in which N2 was used for root canal treatment in human subjects and concluded that it was well 0030-4220/78/0246-0265$01.

IO/O 0

1978 The C. V. Mosby

Co.

265

266

Oral Surg. August, 1978

Labard

Fig. 1. Case I. Tooth embedded in wax block for sectioning. See Figs. 4 and 5 for explanation of B and C.

I. Three root canal cement formulas

Table

I Formula

Percent

No. I:

Hydrocortisone Titanium dioxide Trioxymethylene Lead oxide Zinc oxide

1.5 2.0 7.0 16.5 73.0

Mixed with eugenol Formula

No. 2:

The powder of Formula No. 3 mixed with a liquid consisting of two parts Terracortril (ophthalmic)* and one part eugenol to a thin paste Formula

No. 3:

Hydrocortisone powder Paraformaldehyde Titanium oxide Zinc oxide root canal cement (formula of L. Grossman)

I.0 4.5 2.0 92.5

Mixed with eugenol *Pfizer Inc., New York, N. Y

tolerated. He also pointed out the difficulties of doing endodontic studieson humanteeth and hence the importance of reporting all such material that can be gathered. This article reports on histologic studies done on two human teeth that had been successfully treated with paste or sealer containing PFA and that had to be removed years later for reasonsnot connected with the endodontic treatment. CASE REPORTS CASE

1

A white man, born in 1925, had endodontic treatment of the lower right second premolar in March, 1973. The tooth was measured, reamed, and then filled with N2 root canal cement (see

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Tissue reaction to root canal cements containing PFA

Fig. 2. Case 1. Apex of tooth. The canal is filled with N2 cement. root surface at A. (Hematoxylin and eosin stain. Magnification,

Some of the PDM remains X 85.)

in apposition

267

to the

Fig. 3. Case 1. Higher-power view of the area near A in Fig. 2. Scatterings of the cement are dispersed throughout the PDM all along the root surface. (Hematoxylin and eosin stain. Magnification, x825.)

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Oral Surg. August, I978

Laband

Fig. 4. Case I. Detail

of area B in Fig.

I. (Hematoxylin

Fig. 5. Case I. View of area C in Fig. I, near epithelial (Hematoxylin and eosin stain. Magnification, x85.)

and eosin stain. Magnification,

attachment.

Small

spicule

X520.)

of bone is seen at D.

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Number 2

Tissuereactionto root canalcements containing PFA 269

Fig. 6. Case 1. High-power view of area to the right of D in Fig. 5. Granules of cement connective tissue cells. (Hematoxylin and eosin stain. Magnification, x 520.)

Fig.

7. Case 2. Tooth embedded

in wax block

for sectioning.

are lying between

See Fig. 8 for explanation

of E

the

270

Laband

Oral Surt.

August, I978

Fig. 8. Case 2. High-power view of areaE in Fig. 7. The gut&percha has been lost in sectioning. F denotes the opening of a lateral canal. (Hematoxylin and eosin stain. Magnification, x55.)

Formula No. 1, Table I). This tooth had no further attention until next seen by me in September, 1975 (see Figs. 1 to 6). By this time the clinical crown had disintegrated but there were no signs or symptoms of any periapical disease. On Jan. 8, 1976, the remaining root structure was removed, placed in IO per cent formalin solution, and decalcified; serial sections were cut longitudinally through the region of the apical foramen. There was no inflammatory reaction in the tissues shown; the root canal cement was scattered throughout the tissues and appeared to be well tolerated. It was surprising to note the distance that the cement had migrated, reaching up to the epithelial attachment. There was no evidence of encapsulation of the cement. Two separate sections were prepared with Gram’s stain and an iron stain to eliminate the possibility that the granules as seen in Figs. 3,4, and 6 were either bacteria or clumps of hemoglobin derivatives. Both tests proved negative. CASE

2

A white man born in 1907 was first seen for a routine examination in November, 1970, when a full-mouth set of radiographs was taken. Below is the chronology of treatment of the upper left cuspid.

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271

Fig. 9. Case 2. Higher power view of area F in Fig. 8. The canal is empty of cellular material, containing only (Cl some of the root canal cement. See Figs. 10 and Ii for explanation of H and 1. (Hematoxylin and eosin stain. Magnification, x 130.)

Fig. 10. Case 2. Serial section of area H in Fig. 9. The canal can be. seen lying closer to the middle of the root; cellular substrate is heavily overlain by root canal cement. (Hematoxylin and eosin stain. Magnification, x520.)

272

Laband

Oral Surg. August, I978

Fig. 11. Case 2. Serial section of area i in Fig. 9, which is nearer to the outer surface of the tooth. The canal is filled primarily with cellular material that has a light sprinkling of the granular-appearing cement dispersed throughout. (Hematoxylin and eosin stain. Magnification, X 825.)

Fig. 12. Case 2. Low-power view of lateral canal near outer surface of tooth. The canal (K) is quite close to the lateral wall of the root(L) and the PDM has several large clumps of the cement deposited in it. (Hematoxylin and eosin stain. Magnification, X520.)

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Tissue reaction to root canal cements containing PFA

273

Fig. 13. Case 2. Higher-power view of PDM in Fig. 12. The cement is lying in the fibrous connective tissue of the membrane along with a peppering of smaller granules dispersed throughout the tissues. (Hematoxylin and eosin stain. Magnification, ~825.)

On Aug. 2, 1972, the patient presented with the signs and symptoms of an acute alveolar abscess. There was tenderness to touch and some slight swelling over the apical region. The pulp chamber was opened, reamed, irrigated with sodium hypochlorite solution, and dried with paper points; a medication (Formula No. 2, Table I) was placed. The pulp chamber was sealed with Cavit .* On Dec. 19, 1972, the preparation of the canal was completed and a gutta-percha point was firmly fitted with a cement sealer (Formula No. 3, Table I). On May 10, 1974, the tooth fractured and a post was set into the canal; the crown was then rebuilt with a composite. On Feb. 24, 1976, the post and crown were broken off; the tooth was then extracted. Following the extraction, the tooth was placed in 10 per cent formalin solution and decalcified; serial sections were cut longitudinally through the region of the apical foramen (see Figs. 7 to 13). It is interesting to note that the cement has migrated or has been forced through the lateral canal, has reached the PDM, and lies intimately interwoven in the pulpal tissue of the lateral canal as well as the PDM. It seems to be well tolerated; no signs of any inflammatory infiltrate is to be found. SUMMARY A report is presented of two human teeth treated with root canal cementscontaining PFA. Though the endodontic treatment was successful, the teeth were removed for other

reasons.Histologic sectioning showedthe following: 1. There was good tissuetolerance where the disseminatedroot canal cement came in contact with remaining vital tissues. *Premier Dental Products Co., Philadelphia, Pa.

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Oral Surg. August, 1978

Laband

(It should be pointed out that the absenceof an inflammatory responseor even the absenceof chronic inflammatory cells adjacent to the particles of cement in the tissue could be attributable to: (1) the anti-inflammatory action of the steroid in the preparation; (2) the fixing properties of the paraformaldehyde; it is possible that the immediately contiguous tissuewas fixed before cells could find their way into the tissuespaces;(3) the combined action of the steroid and the paraformaldehyde could even be synergistic. The anti-inflammatory activity in and the fixation of adjacent tissue could have occurred simultaneously. Thus, microscopically such a section of tissue could be interpreted as being normal when indeed it had been fixed prior to removal and thereby made incapable of manifesting responses.) 2. Dissemination of the root canal cement-it was found dispersedthroughout the surrounding tissuesas far as the epithelial attachment. 3. No evidence of encapsulationwas seenin any of the slides. REFERENCES 1. Langeland, K.: Root Canal Sealants and Pastes, Dent. Clin. North Am. 18: 309, 1974. 2. Spangberg, L., and Langeland, K.: Biologic Effects of Dental Materials, ORAL SURG. 35: 402, 1973. 3. Bordoni, N., and Erausquin, .I.: Periapical Tissue Reaction to Root Canal Filling With a Paste Containing 7 Per Cent Trioxymethylene, ORAL SURG. 29: 907, 1970. 4. Engstrom, B., and Spangberg, L.: Effect of Root Canal Filling Material N2 When Used for Filling After Partial Pulpectomy, Sven. Tandlak. Tidskr. 62: 8 15, 1969. 5. Orlay, H. G.: Overfilling in Root Canal Treatment, Br. Dent, J. 120: 376, 1966. 6. Ehrmann, E. H.: Root Canal Treatment With N2, Aust. Dent. J. 8: 434, 1963. 7. Overdiek, H. F., and Sauerwein, E.: Vergleichende Untersuchungen der Gewebsreaktion nach Implantation von N2 und N2 mit Cortison, Zahn. Rund. 77: I, 1968. 8. Rowe, A. H. R.: Effect of Root Filling Materials on the Periapical Tissues, Br. Dent. .I. 122: 98, 1967. 9. Snyder, D., Seltzer, S., and Moodnick, R.: Effects of N2 in Experimental Endodontic Therapy. ORAL SURG.

21:

635,

1966.

IO. Barker, B. C. W., and Lockett, B. C.: Periapical Response to N2 and Other Paraformaldehyde Compounds Confined Within or Extruded Beyond the Apices of Dog Root Canals, Dent. Pratt. 22: 370, 1972. Il. Muruzabal, M., Erausquin, J., and Devoto, F. C. H.: A Study of Periapical Overfilling in Root Canal Treatment in the Molar of Rat, Arch. Oral Biol. 11: 373, 1966. 12. Erausquin, J., and Muruzabal, M.: Tissue Reaction to Root Canal Cements in the Rat Molar, ORAL SURG. 26: 360, 1968. 13. Friend, L. A., and Browne, R. M.: Tissue Reactions to Some Root Filling Materials, Br. Dent. J. 125: 291, 1968. 14. Laband, P.: Clinical Evaluation of a Root Canal Cement That Contains Paraformaldehyde, J. Am. Dent. Assoc. 93: 583, 1976. 15. Rowe, A. H.: Treatment With N2 Root Canal Sealer, Br. Dent. J. 117: 27, 1964. Reprint

requests

to:

Dr. Peter Laband 39 Main St. Northampton, Mass.

01060