Apicectomy: A comparative clinical study of amalgam and glass ionomer cement as apical sealants L. Zetterqvist, DDS,a G. Hall, DDS,a and A. Holmlund, DDS, PhD,b Huddinge, Sweden SCHOOL OF DENTISTRY, KAROLINSKA INSTITUTE Healing capacity after apicectomy was investigated in a randomized clinical study sealed with either amalgam or glass ionomer cement. The results were evaluated radiographically after 1 year. The success rate was high for both materials: 91% glass ionomer cement. Contamination with moisture and blood adversely affected materials and was significantly more frequent in unsuccessful cases. (ORAL SURC ORAL MED ORAL PATHOL 1991;71:489-91)
R
etrograde root canal filling after apicectomy is a valuable procedure in insufficiently sealed root canals inaccessible for conventional endodontic therapy. An adequate apical seal may allow leakage of microorganisms and proteolytic enzymesthat limit healing of the periapical tissues; retrograde filling materials must therefore seal hermetically.1-7 Amalgam has been commonly used for retrograde filling of root canals with good clinical results. However, disadvantages with amalgam are numerous. Shrinkage contraction and expansion of up to 10 pm/cm result in poor adaptation between filling and cavity walls.*, 9 Considerable leakage has been observed between the retrograde amalgam fillings and surrounding dentin. lo*’ 1 Furthermore, the introduction of mercury and heavy metal alloys into the body tissuesis controversial; recent studies indicate local as well as systemic influences.12Tl3 Glass ionomer cement (GC) has been proposed as an alternative to amalgam; recent studies have shown low microleakage and only insignificant tissue reactions in animal experiments.*4,l5 We report a randomized clinical study comparing amalgam and GC as retrograde fillings in apical surgery. MATERIAL
AND METHODS
Patients. The participants in the study were 85 consecutive patients at the Department of Oral SurBAssistant Professor, Department of Oral Surgery. bAssociate Professor, Department of Oral Surgery. 7115121353
of 105 teeth apically clinically and for amalgam and 89% for the outcome for both
gery, Karolinska Institute, with 105 teeth indicated for periapical surgery (i.e., teeth with periapical lesions not accessible to conventional endodontic treatment). Treatment. Surgery was performed by two specialist oral surgeons (L.Z. and A.H.). After injection of 3.6 ml lidocaine hydrochloride with 12.5 pg/rnl epinephrine, a buccal full-thickness mucoperiosteal flap was raised. Any bone covering the apical area, and any granulation tissue, were removed. Apicectomy was performed and the root canal prepared in a boxtype manner with a No. 33% inverted cone bur. Each tooth was filled with either amalgam (Amalcap nongamma-2; Vivadent, Schaan, Liechtenstein) or GC (Chem-Fil, DeTrey, Zurich, Switzerland), in accordance with a randomization form. One week after surgery two standardized intraoral radiographs were taken of each apicectomized tooth. Follow-up. All patients were seen 1 year after surgery for clinical and radiographic examination. Standardized radiographs were again obtained and interpreted by one of the authors also trained in oral radiology (L.Z.). Findings were then classified as follows: 1. Complete healing. No clinical symptoms were present. A normal lamina dura was visible on the radiograph, or width of apical periodontal space was slightly increased; less than twice of noninvolved parts of the root was present (Figs. 1 and 2). A defect in the lamina dura (maximum 1 mm2) adjacent to the retrograde filling was considered to be complete healing if the patient showed no clinical symptoms. 489
490
Zetterqvist, Hall, and Holmlund
ORAl.
SLRG
ORAl.
MED ORAL PATHOI April 1991
I. Number of teeth completely healed, improved, not improved, or failed after apicoectomy and retrograde sealing with amalgam or GC /--No :
Table
Apical sealant
Teeth sealed
Amalgam GC
Fig.
1. Complete healing. Apicectomy and retrograde
filling with amalgam on left maxillary lateral incisor. Radiographs (A) 1 week postoperatively and (B) at l-year follow-up.
52 53
Complete Improvehealing ! ment 28 36
19 II
improvement 1 I
Failure 4 5
fillings. This difference was not statistically significant (NS). Improvement was observed in 37% of amalgam-sealed teeth and in 21% after GC sealing (NS). Thus 91% showed complete healing or improvement after sealing with amalgam and 89% after GC (NS). Four amalgam- and five GC-sealed teeth were classified as failures (NS). The failure rates for casescontaminated by moisture or blood during apical sealing was 22%, compared with 5% for casesin which no such contamination occurred (p < 0.05). No difference was observed between teeth sealed with amalgam or GC when the rate of healing was analyzed in relation to such contamination. DISCUSSION
Fig. 2. Complete healing. Apicectomy and retrograde filling with GC on right maxillary canine. Radiographs (A) 1 week postoperatively and (B) at l-year follow-up. GC without contrast was used.
2. Improvement. Obvious radiographic signs of healing were present without clinical symptoms. 3. No improvement. No radiographic evidence of healing was present, but the tooth was symptomless. 4. Failure. Radiographic evidence of an increased periradicular radiolucency or clinical symptoms of periradicular osteitis were present. Statistical analysis. Differences between teeth sealed with amalgam and GC were analyzed by the chi-square test. RESULTS
Of 105 teeth, 52 were sealedwith amalgam and 53 with GC. No difference in successor failure rates were observed between teeth sealed with amalgam or GC (Table I). Complete healing was observed in 54% of teeth after amalgam and in 68% of teeth after GC
An efficient apical seal has been regarded as the single most important factor for successfulperiapical surgery.iT3In the present study the successrate was high for sealswith both amalgam and GC; there were no significant intergroup differences. The overall successrate for the serieswas slightly higher than in previously reported studies.**r6-r8 Several factors may have contributed to this result. More stringent indications for periapical surgery have been adopted during the last decade; the difference thus partly reflects dissimilarities in patient selection. Other factors may be slight differences in criteria for assessing healing and different materials used for periapical seal. Our investigation is a l-year follow-up, and failures may occur later. A 3-year follow-up is in progress. Experimental studies have revealed that microleakage is greater for amalgam apical seals than for GC.‘Og1l However, this is not reflected in the results of this study. Other factors, such as the size of the periapical lesion, the degreeof inflammation, and lossof bone over the periapical area, were also investigated in this study but did not affect the successrate. The results are thus contradictory to findings by Hirsch et a1.2 Contamination with moisture or blood during the apical seal procedure did, on the other hand, adversely
Volume 7 1 Number 4
affect the success rate; contamination was significantly more frequent in the unsuccessful group. Although GC clinically seemed more sensitive to contamination by moisture and blood, no significant differences were found between GC and amalgam groups. However, a proper surgical technique with careful hemostasis must be emphasized. The results indicate no significant differences in success rates between amalgam and GC as apical sealants.However, amalgam has other disadvantages, such as a tendency to corrode and leakage of mercury into the periapical tissues. In recent experimental studies14*l5 GC has shown a high degree of biocompatibility, and this is borne out in our clinical study. GC may therefore be considered an alternative apical sealant material to amalgam. REFERENCES
1. Harty FJ, Parkins BJ, Wengraf AM. The successrate of apicoectomy: a retrospective study of 1016 cases. Br Dent J 1970:129:407-13. 2. Hirsch JM, Ahlstriim U, Henrikson PA, Heyden G, Peterson LE. Periapical surgery. Int J Oral Sura 1979:8:173-8.5. 3. Rud J, Andreasen JQ; JensenJEM. Radiographic criteria for the assessmentof healing after endodontic surgery. Int J Oral Surg 1972;1:195-214. 4. Dahl BL, Tronstadt L. Biological test of an experimental glass ionomer (silicopolyacrylate) cement. J Oral Rehab 1976;3: 19-24. 5. Dahltn G, Bergenholtz G. Endotoxic activity in teeth with necrotic pulps. J Dent Res 1980;59:1033-40. 6. Malooley J Jr, Patterson SS, Kafrawy A. Responseof periapical pathosis to endodontic treatment in monkeys. ORAL SURC ORAL MED ORAL PATHOL 1979;47:545-54.
7. Mijller AJR, Fabricius L, Dahlen G, Ghman AE, Heyden G. Influence on periapical tissuesof indigenous oral bacteria and
Amalgam and glass ionomer as apical sealants
491
necrotic pulp tissue in monkeys. Stand J Dent Res 1981;89: 475-84. 8. Boyer DB, Torney DL. Microleakage of high copper amalgams [Abstract]. J Dent Res 1979;58A:394. 9. Stabholtz A, Shani J, Friedman S, Abed J. Marginal adaptation of retrograde fillings and its correlations with sealability. J Endod 1985;11:218-23. 10. Barkhordar RA, Pelzner RB, Stark MM. Use of glass ionomers as retrofilling materials. ORAL SURG ORAL MED ORAL PATHOL 1989;67:734-9. 11. Zetterqvist L, Anneroth G, Danin J, Ridding K. Microleakage
12. 13.
14.
15.
16.
17. 18.
of retrograde fillings: a comparative investigation between amalgam and glass ionomer cement in vitro. Int Endod J 1988;21:1-8. Lind P, Hurlen B, Lyberg T, Aas E. Amalgam-related oral lichenoid reaction. Stand J Dent Res 1986;94:448-51. Nylander M, Friberg L, Eggleston D, Bjorkman L. Mercury accumulation in tissuesfrom dental staff and controls in relation to exposure. Swed Dent J 1989;13:235-43. Lethinen R. Tissue reaction of a glass ionomer cement in the rat: a possible material for apicectomy using retrograde filling [abstract]. Int J Oral Surg 1985;14:105, Zetterqvist L, Anneroth G, Nordenram A. Glass-ionomer cement as retrograde filling material an experimental investigation in monkeys. Int J Oral Maxillofac Surg 1987;16:459-64. Nord PG. Retrograde rootfilling with Cavit: a clinical and roentgenological study. Svensk Tandlak T 1970;63:261-73(in Swedish). Nordenram A. Biobond for retrograde root filling in apicoectomy. Stand J Dent Res 1970;78:251-5. PerssonG, Lennartson B, Lundstrom 0. Results of retrograde filling with special reference to amalgam and Cavit as root filling material. Swed Dent J 1974;67:123-34.
Reprint requests to:
L. Zetterqvist, DDS Department of Oral Surgery School of Dentistry Karolinska Institute Box 4064 S-141 04 Huddinge, Sweden
R
etrograde root canal filling after apicectomy is a valuable procedure in insufficiently sealed root canals inaccessible for conventional endodontic therapy. An adequate apical seal may allow leakage of microorganisms and proteolytic enzymesthat limit healing of the periapical tissues; retrograde filling materials must therefore seal hermetically.1-7 Amalgam has been commonly used for retrograde filling of root canals with good clinical results. However, disadvantages with amalgam are numerous. Shrinkage contraction and expansion of up to 10 pm/cm result in poor adaptation between filling and cavity walls.*, 9 Considerable leakage has been observed between the retrograde amalgam fillings and surrounding dentin. lo*’ 1 Furthermore, the introduction of mercury and heavy metal alloys into the body tissuesis controversial; recent studies indicate local as well as systemic influences.12Tl3 Glass ionomer cement (GC) has been proposed as an alternative to amalgam; recent studies have shown low microleakage and only insignificant tissue reactions in animal experiments.*4,l5 We report a randomized clinical study comparing amalgam and GC as retrograde fillings in apical surgery. MATERIAL
AND METHODS
Patients. The participants in the study were 85 consecutive patients at the Department of Oral SurBAssistant Professor, Department of Oral Surgery. bAssociate Professor, Department of Oral Surgery. 7115121353
of 105 teeth apically clinically and for amalgam and 89% for the outcome for both
gery, Karolinska Institute, with 105 teeth indicated for periapical surgery (i.e., teeth with periapical lesions not accessible to conventional endodontic treatment). Treatment. Surgery was performed by two specialist oral surgeons (L.Z. and A.H.). After injection of 3.6 ml lidocaine hydrochloride with 12.5 pg/rnl epinephrine, a buccal full-thickness mucoperiosteal flap was raised. Any bone covering the apical area, and any granulation tissue, were removed. Apicectomy was performed and the root canal prepared in a boxtype manner with a No. 33% inverted cone bur. Each tooth was filled with either amalgam (Amalcap nongamma-2; Vivadent, Schaan, Liechtenstein) or GC (Chem-Fil, DeTrey, Zurich, Switzerland), in accordance with a randomization form. One week after surgery two standardized intraoral radiographs were taken of each apicectomized tooth. Follow-up. All patients were seen 1 year after surgery for clinical and radiographic examination. Standardized radiographs were again obtained and interpreted by one of the authors also trained in oral radiology (L.Z.). Findings were then classified as follows: 1. Complete healing. No clinical symptoms were present. A normal lamina dura was visible on the radiograph, or width of apical periodontal space was slightly increased; less than twice of noninvolved parts of the root was present (Figs. 1 and 2). A defect in the lamina dura (maximum 1 mm2) adjacent to the retrograde filling was considered to be complete healing if the patient showed no clinical symptoms. 489
490
Zetterqvist, Hall, and Holmlund
ORAl.
SLRG
ORAl.
MED ORAL PATHOI April 1991
I. Number of teeth completely healed, improved, not improved, or failed after apicoectomy and retrograde sealing with amalgam or GC /--No :
Table
Apical sealant
Teeth sealed
Amalgam GC
Fig.
1. Complete healing. Apicectomy and retrograde
filling with amalgam on left maxillary lateral incisor. Radiographs (A) 1 week postoperatively and (B) at l-year follow-up.
52 53
Complete Improvehealing ! ment 28 36
19 II
improvement 1 I
Failure 4 5
fillings. This difference was not statistically significant (NS). Improvement was observed in 37% of amalgam-sealed teeth and in 21% after GC sealing (NS). Thus 91% showed complete healing or improvement after sealing with amalgam and 89% after GC (NS). Four amalgam- and five GC-sealed teeth were classified as failures (NS). The failure rates for casescontaminated by moisture or blood during apical sealing was 22%, compared with 5% for casesin which no such contamination occurred (p < 0.05). No difference was observed between teeth sealed with amalgam or GC when the rate of healing was analyzed in relation to such contamination. DISCUSSION
Fig. 2. Complete healing. Apicectomy and retrograde filling with GC on right maxillary canine. Radiographs (A) 1 week postoperatively and (B) at l-year follow-up. GC without contrast was used.
2. Improvement. Obvious radiographic signs of healing were present without clinical symptoms. 3. No improvement. No radiographic evidence of healing was present, but the tooth was symptomless. 4. Failure. Radiographic evidence of an increased periradicular radiolucency or clinical symptoms of periradicular osteitis were present. Statistical analysis. Differences between teeth sealed with amalgam and GC were analyzed by the chi-square test. RESULTS
Of 105 teeth, 52 were sealedwith amalgam and 53 with GC. No difference in successor failure rates were observed between teeth sealed with amalgam or GC (Table I). Complete healing was observed in 54% of teeth after amalgam and in 68% of teeth after GC
An efficient apical seal has been regarded as the single most important factor for successfulperiapical surgery.iT3In the present study the successrate was high for sealswith both amalgam and GC; there were no significant intergroup differences. The overall successrate for the serieswas slightly higher than in previously reported studies.**r6-r8 Several factors may have contributed to this result. More stringent indications for periapical surgery have been adopted during the last decade; the difference thus partly reflects dissimilarities in patient selection. Other factors may be slight differences in criteria for assessing healing and different materials used for periapical seal. Our investigation is a l-year follow-up, and failures may occur later. A 3-year follow-up is in progress. Experimental studies have revealed that microleakage is greater for amalgam apical seals than for GC.‘Og1l However, this is not reflected in the results of this study. Other factors, such as the size of the periapical lesion, the degreeof inflammation, and lossof bone over the periapical area, were also investigated in this study but did not affect the successrate. The results are thus contradictory to findings by Hirsch et a1.2 Contamination with moisture or blood during the apical seal procedure did, on the other hand, adversely
Volume 7 1 Number 4
affect the success rate; contamination was significantly more frequent in the unsuccessful group. Although GC clinically seemed more sensitive to contamination by moisture and blood, no significant differences were found between GC and amalgam groups. However, a proper surgical technique with careful hemostasis must be emphasized. The results indicate no significant differences in success rates between amalgam and GC as apical sealants.However, amalgam has other disadvantages, such as a tendency to corrode and leakage of mercury into the periapical tissues. In recent experimental studies14*l5 GC has shown a high degree of biocompatibility, and this is borne out in our clinical study. GC may therefore be considered an alternative apical sealant material to amalgam. REFERENCES
1. Harty FJ, Parkins BJ, Wengraf AM. The successrate of apicoectomy: a retrospective study of 1016 cases. Br Dent J 1970:129:407-13. 2. Hirsch JM, Ahlstriim U, Henrikson PA, Heyden G, Peterson LE. Periapical surgery. Int J Oral Sura 1979:8:173-8.5. 3. Rud J, Andreasen JQ; JensenJEM. Radiographic criteria for the assessmentof healing after endodontic surgery. Int J Oral Surg 1972;1:195-214. 4. Dahl BL, Tronstadt L. Biological test of an experimental glass ionomer (silicopolyacrylate) cement. J Oral Rehab 1976;3: 19-24. 5. Dahltn G, Bergenholtz G. Endotoxic activity in teeth with necrotic pulps. J Dent Res 1980;59:1033-40. 6. Malooley J Jr, Patterson SS, Kafrawy A. Responseof periapical pathosis to endodontic treatment in monkeys. ORAL SURC ORAL MED ORAL PATHOL 1979;47:545-54.
7. Mijller AJR, Fabricius L, Dahlen G, Ghman AE, Heyden G. Influence on periapical tissuesof indigenous oral bacteria and
Amalgam and glass ionomer as apical sealants
491
necrotic pulp tissue in monkeys. Stand J Dent Res 1981;89: 475-84. 8. Boyer DB, Torney DL. Microleakage of high copper amalgams [Abstract]. J Dent Res 1979;58A:394. 9. Stabholtz A, Shani J, Friedman S, Abed J. Marginal adaptation of retrograde fillings and its correlations with sealability. J Endod 1985;11:218-23. 10. Barkhordar RA, Pelzner RB, Stark MM. Use of glass ionomers as retrofilling materials. ORAL SURG ORAL MED ORAL PATHOL 1989;67:734-9. 11. Zetterqvist L, Anneroth G, Danin J, Ridding K. Microleakage
12. 13.
14.
15.
16.
17. 18.
of retrograde fillings: a comparative investigation between amalgam and glass ionomer cement in vitro. Int Endod J 1988;21:1-8. Lind P, Hurlen B, Lyberg T, Aas E. Amalgam-related oral lichenoid reaction. Stand J Dent Res 1986;94:448-51. Nylander M, Friberg L, Eggleston D, Bjorkman L. Mercury accumulation in tissuesfrom dental staff and controls in relation to exposure. Swed Dent J 1989;13:235-43. Lethinen R. Tissue reaction of a glass ionomer cement in the rat: a possible material for apicectomy using retrograde filling [abstract]. Int J Oral Surg 1985;14:105, Zetterqvist L, Anneroth G, Nordenram A. Glass-ionomer cement as retrograde filling material an experimental investigation in monkeys. Int J Oral Maxillofac Surg 1987;16:459-64. Nord PG. Retrograde rootfilling with Cavit: a clinical and roentgenological study. Svensk Tandlak T 1970;63:261-73(in Swedish). Nordenram A. Biobond for retrograde root filling in apicoectomy. Stand J Dent Res 1970;78:251-5. PerssonG, Lennartson B, Lundstrom 0. Results of retrograde filling with special reference to amalgam and Cavit as root filling material. Swed Dent J 1974;67:123-34.
Reprint requests to:
L. Zetterqvist, DDS Department of Oral Surgery School of Dentistry Karolinska Institute Box 4064 S-141 04 Huddinge, Sweden
