Comparison of apical sealing methods

Comparison of apical sealing methods A preliminary

HOSI’ITAL

FOR

report

JOINT

DISEASES

AND

RIEDICAL

CESTER

A comparison of the seal provided by gutta-percha root canal filling, heat-sealed gutta-pcrcha, retrograde amalgam filling, and retrograde Durclon filling was made 1)~ observation of dye penetration around the abow filling matrrials in extracted teeth. A small Init not significant diffcrcnce bckwccn guttapercha, heat-sealed guttapercha, and retrogradr amalgam was noted. Het,rogmde Durelon tilling gave a poor seal in comparison to gutta-prrcha and retrograde amalgam filling, hut the difference between it and the heat seal was not significant.

A

picoectomy and retrograde fillin g is an acceptctl method of sealing root canals. However, heat seal of exposed qutta-percha is gaining in popularity for retreating canals which have been filled with gutta-pcrcha. I’olycarboxylatc cements have been suggested for use as root canal sealers.‘.” These cements have been shown to adhere to tooth structure, both enamel and dentin,“-” and have low tissue toxicity.‘-‘” The purpose of this study was to compare a polycarboxylate cement, l)urelon,t as a retrograde filling material and the following sealing methods: rttrograde amalgam filling, heat-sealetl gutta-percha, ant1 laterally condensed guttapercha. METHOD

Extracted teeth wcrc disinfcctctl by immersion in 5 ner cent NaOCI for 24 hours. Root surfaces were paintedS to prevent lcakagc through cracks or lateral “Endodontic Resident, Hospital for Joint Diseases and Medical Center. **Attending in Endodontics, Hospital for Joint Diseases and Medical Endodontics Division, Reth Israel Hospital and Mcdicnl Center. ***Chief of Oral Surgery, Hospital for Joint Disenscx and Mrdical Center. tDurelon, Premier Dental Products, Philadelpliia, Pa. $Paetra ‘Name& Pactra Industries, Los Angeles, Calif.

Center;

Chief,

Volume Number

Comparison

39 5

Fig.

1. One

end

of divider

in bur

hole and

of apical sealing methods

the other

used to mark

root

807

surface.

canals. Canals were instrumented 5 mm. beyond the apex with a No. 30 file and filled with gutta-percha, using lateral condensation of multiple points and Procosol” root canal sealer. Coronal access was sealed with sticky wax. Maxillary and mandibular anterior and posterior teeth were used and canals were treated separately. Filled canals were divided into groups of about thirteen as follows: Group l-no additional treatment ; Group 2-apicoectomy and heat seal of gutta-percha in the canal ; Group 3-apicoectomy and retrograde amalgam filling ; Group 4--apicoectomy and retrograde Durelon filling. Apicoectomy involved removal of apical 1 mm. perpendicular to the long axis with a sharp blade. Retrograde fillings were prepared with a No. 2 round bur entering the canal axially from the apical surface to a depth of 2 mm. Amalgam was placed with a retrograde amalgam carrier and condensed with hand instruments. Durelon was mixed according to packaged instructions for cement base and placed with a syringe.t All teeth were immersed in 2 per cent aqueous methylene blue and specimens were removed for examination after’l, 2, and 3 weeks. When the teeth were removed from the dye, they were wiped dry with a paper towel. A No. l/s round bur hole was made into the chamber from a proximal surface near the cementoenamel junction. A drafting divider was used to measure root length by seating one point in the bur and adjusting the divider until the other point touched the apex. The distance between divider points was measured in millimeters and reduced by 0.5 mm. The divider was set to this reduced length. One point was seated in the bur hole and the other was used to mark the root surface as shown in Fig. 1. The *Proco-sol, tcentrix,

Proco-sol Clev-Dent

Chemical Division,

Co., W. Conshohocken, Cleveland, Ohio.

Pa.

808

Barry,

Heyman,

and Elias

/ I

Oral May,

I ,,I

I I

,

,,I

l%mm

I

:.

Surg. 1975

:

\

2mm

\

2 ‘/2 m m \

3mm

\

3’/2mm \

4mm

\

4%

mm

Space by

occupied

retrograde

tilling ‘/i

round

hole

to

the

divider

bur hold

point

Fig.

3.

root structure was ground off to the mark in a plane perpendicular to the long axis of the tooth, using ten safe-side discs on the same mandrel mounted on a dental lathe. Newly exposed root surface was examined for evidence of dye. The root was removed in 0.5 mm. increments until 4.5 mm. had been removed as diagrammed in Fig. 2. The measurement at which the dye was last noted was recorded as depth of penetration. RESULTS One

week

Group 1. Group 2. from apex). Group 3. Group 4. Two

All teeth showed dye penetration to 0.5 mm. One showed no dye penetration (no dye evident at first cut 0.5 mti. Others showed dye penetration to 1, 1.5 (two teeth), and 2 mm. Dye penetration to 0.5 (three teeth), 1, and 3.5 mm. Dye penetration to 1 (two teeth), 1.5 (two teeth), and 3 mm.

weeks

Specimens examined after immersion in dye for 2 weeks showed the following results : Group 1. No penetration (two teeth), 0.5, and 1 mm.

Volume Number

Co~~~pwison

39 5

of

apical

sealing methods

809

GUTTA PERCHA

HEAT SEAL

AMALGAM

DURELDN

R

,I

1 WEEKS21N DYE 3 Fig.

3.

Group 8. Dye penetration to 1, 3, and 3.5 mm. Group 3. No penetration, 0.5, and 2 mm. Group 4. Dye penetration to 1, 2, and 4.5 mm Three

weeks

Specimens examined after 3 weeks’ immersion in dye gave the following results : Groul) 1. Dye penetration to 0.5 (two teeth) and 1 mm. (three teeth). Gmp ,“. Dye penetration to 1, 1.5 (two teeth), and 2 mm. Growl> 3. h-o penetration in three canals, dye to 1.5 and 2 mm. (two teeth). Group 4. Dye penetration to 1 and 3 mm. (four teeth). Results are shown graphically in Fig. 3. Different groups were compared with each other using a t test for statistical evaluation. DISCUSSION

Although differences in penetration were noted in the gutta-percha and retrograde amalgam, heat-sealed gutta-percha and retrograde amalgam, and hcat-

Oral May,

Heymnn, and Elias

810

Barry,

Table

1. Results of paired comparisons Not Gutta-percha Retrograde

significant

Surg. 1975

Significant

amalgam

Gutta-perch Durelon

P <

.OOl

Heat seal Retrograde

amalgam

Gutta-per&a Heat seal

P <

,001

Heat seal Retrograde

Durelon

Retrograde Retrograde

P <

.02

amalgam Durelon

sealed gutta-percha and retrograde Durelon cement, the differences were not significant (Table I). Significant differences were noted between the following pairs : gutta-percha and retrograde Durelon, gutta-percha and heat-sealed gutta-percha, and guttapercha and retrograde amalgam (Table I). Although there was no significant difference between heat-sealed gutta-percha and retrograde amalgam, the latter may be better. If poor seal by the present gutta-percha filling were the factor necessitating re-treatment, contact with a hot instrument on the gutta-percha could hardly be expected to improve the “seal.” The significant difference between gutta-percha and heat-sealed gutta-percha could be due to loss of filling material during the heat seal; that is, gutta-percha expands when heated, and when the hot instrument is removed some of the gutta-percha adheres to it and the remainder recedes from canal walls upon cooling. If necrotic debris were the causative factor, then removal by means of the amalgam preparation would be the logical approach. There is also a greater chance of sealing lateral canals becauseof the depth of the amalgam preparation. All root canal fillings mere done by the same operator and thus were of comparable quality. This is significant in view of the difference noted between heat seals and gutta-percha fillings in this study. If the canal were inadequately filled to begin with, then the heat seal might not bc of any value and a retrograde amalgam filling would be indicated. Retrograde Durelon fillings performed poorly in comparison to gutta-percha and retrograde amalgam fillings. It wou!d be better to use amalgam for retrograde filling. CONCLUSION

The sealsafforded by gutta-percha root canal filling, heat-sealed gutta-percha, and retrograde amalgam filling were not significantly different from each other. However, for reasons discussed, retrograde amalgam filling may be preferable to heat-sealed gutta-percha. Retrograde Durelon filling gave a poor seal in comparison to gutta-percha and retrograde amalgam filling, but the difference between it and the heat seal was not significant. REFERENCES

1. Greive, 19-22,

A. R.: 1972.

Sealing

Properties

of

Cements

Used

in

Root

Filling,

Br.

Dent.

J.

132:

Volume Number

39 5

Comparison

of

apical sealing

methods 811

2. McLean, J. W.: A Five Year Case History of a Polycarboxylate Cement Root Filling, J. Hr. Endo. Sot. 5: 20. 1971. 3. Smith, D. C.: Dental Cements, Dent. Clin. North Am. 15: 3-31, 1971. 4. Beech, D. R.: Adhesion of Polgcarboxylate Cement to Human Dentin, J. Dent. Res. 52: 959, i973. 5. McLean, J.: Polycarboxylate Cements: Five Years’ Experience in General Practice, Br. Dent. J. 132: 9-15, 1972. of a Carboxylate Adhesive 6. Phillips, R. W., Swartz, M. L., and Rhodes, B.: An Evaluation Cement, J. Am. Dent. Assoc. 81: 1353-1359, 1970. 7. Smith, D. C.: A New Dental Cement, Br. Dent. J. 125: 381-385, 1968. 8. Smith, D. C.: A Review of the Zinc Polycarboxylate Cements, J. Can. Dent. Assoc. 37: --22.29.-_

lR71. I.-----

9. Beagrie, G. H., Main, J. H. P., and Smith, D. C. : Inflammatory Reaction Evoked by Zinc Polvacrvlate and Zinc Eugenate Cements: a Comnarison. Br. Dent. J. 132: 351-357. 1972. 10. Beigriei G. S., Main, J. -H. P., Smith, ‘D. C., and Walshaw, Paula R.: Polycarboxylate Cement as a Pulp Capping Agent, J. Can. Dent. Assoc. 40: 378383, 1974. 11. Safer, D. S., Avery, J. K., and Fox, C. F. : Histopathological Evaluation of the Effects of New Polycarboxylate Cements on Monkey Pulps, ORAL SURG. 33: 966-975, 1972. 12. Truelove, E. L., Mitchell, D. F., and Phillips, R. W. : Biologic Evaluation of a Carboxylate Cement, J. Dent. Res. 50: 166, 1971. Reprint requests to: Dr. Gene N. Barry 4623 Pin Oak Bellaire, Texas 77401