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Cytotoxicity of denture base resins: Effect of water bath and microwave postpolymerization heat treatments
MAKZOUME´
THE JOURNAL OF PROSTHETIC DENTISTRY
5. Schiesser FJ. The neutral zone and polished surfaces in complete dentures. J Prosthet Dent 1964;14:854-65. 6. Beresin VE, Schiesser FJ. The neutral zone in complete dentures. J Prosthet Dent 1976;36:356-67. 7. Lott F, Levin B. Flange technique: an anatomic and physiologic approach to increased retention, function, comfort and appearance of dentures. J Prosthet Dent 1966;16:394-413. 8. Miller WP, Monteith B, Heath MR. The effect of variation of the lingual shape of mandibular complete dentures on lingual resistance to lifting forces. Gerodontology 1998;15:113-9. 9. Barrenas L, Odman P. Myodynamic and conventional construction of complete dentures: a comparative study of comfort and function. J Oral Rehabil 1989;16:457-65. 10. Ohkubo C, Hanatini S, Hosoi T, Mizuno Y. Neutral zone approach for denture fabrication for a partial glossectomy patient: a clinical report. J Prosthet Dent 2000;84:390-3. 11. Kokubo Y, Fukushima S, Sato J, Seto K. Arrangement of artificial teeth in the neutral zone after surgical reconstruction of the mandible: a clinical report. J Prosthet Dent 2002;88:125-7. 12. Fahmy FM, Kharat DU. A study of the importance of the neutral zone in complete dentures. J Prosthet Dent 1990;64:459-62. 13. Neill DJ, Glaysher JK. Identifying the denture space. J Oral Rehabil 1982; 9:259-77. 14. Beresin VE, Schiesser FJ. The neutral zone in complete and partial dentures. 2nd ed. St Louis: Mosby; 1978. p. 73-86. 15. Lear CS, Flanagan JB Jr, Moorrees CF. The frequency of deglutition in man. Arch Oral Biol 1965;10:83-100. 16. Eibling DE, Cavo JW Jr. Dysphagia. In: Calhoun K, Eibling DE, Wax MK. Expert guide to otolaryngology. Philadelphia: American College of Physicians; 2001. p. 282.
Noteworthy Abstracts of the Current Literature
17. Shelton RL Jr, Bosma JF, Sheets BV. Tongue, hyoid and larynx displacement in swallow and phonation. J Applied Phys 1960;15:283-8. 18. Karlsson S, Hedegard B. A study of the reproducibility of the functional denture space with a dynamic impression technique. J Prosthet Dent 1979;41:21-5. 19. Fahmi FM. The position of the neutral zone in relation to the alveolar ridge. J Prosthet Dent 1992;67:805-9. 20. Stromberg WR, Hickey JC. Comparison of physiologically and manually formed denture bases. J Prosthet Dent 1965;15:213-30. 21. Atwood DA. The problem of reduction of residual ridges. In: Winkler S. Essentials of complete denture prosthodontics. 2nd ed. St. Louis: Mosby Year Book; 1988. p. 22-38. Reprint requests to: DR JOSEPH E. MAKZOUME´ BADARO, 25 I. MEDAWAR STREET BADARO CENTER BEIRUT 2058-7007 LEBANON FAX: 00961-1-380530 E-MAIL: [email protected] 0022-3913/$30.00 Copyright Ó 2004 by The Editorial Council of The Journal of Prosthetic Dentistry
doi:10.1016/j.prosdent.2004.09.010
Cytotoxicity of denture base resins: Effect of water bath and microwave postpolymerization heat treatments Jorge JH, Giampaolo ET, Vergani CE, Machado AL, Pavarina AC, Carlos IZ. Int J Prosthodont 2004;17:340-4.
Purpose: This study compared the effect of two postpolymerization heat treatments on the cytotoxicity of three denture base resins on L929 cells using 3H-thymidine incorporation and MTT assays. Materials and Methods: Sample disks of Lucitone 550, QC 20, and Acron MC resins were fabricated under aseptic conditions and stored in distilled water at 37°C for 48 hours. Specimens were then divided into three groups: (1) heat treated in microwave oven for 3 minutes at 500 W; (2) heat treated in water bath at 55°C for 60 minutes; and (3) no heat treatment. Eluates were prepared by placing three disks into a sterile glass vial with 9 mL of Eagle’s medium and incubating at 37°C for 24 hours. The cytotoxic effect from the eluates was evaluated using the 3H-thymidine incorporation and MTT assays, which reflect DNA synthesis levels and cell metabolism, respectively. Results: The components leached from the resins were cytotoxic to L929 cells when 3H-thymidine incorporation assay was employed. In contrast, eluates from all resins revealed noncytotoxic effects as measured by MTT assay. For both MTT assay and 3H-thymidine incorporation, the heat treatments did not decrease the cytotoxicity of the materials tested. Conclusion: Resins were graded by 3H-thymidine incorporation assay as slightly cytotoxic and by MTT assay as noncytotoxic. Cytotoxicity of the denture base materials was not influenced by microwave or water bath heat treatment.—Reprinted with permission of Quintessence Publishing.
568
VOLUME 92 NUMBER 6
THE JOURNAL OF PROSTHETIC DENTISTRY
5. Schiesser FJ. The neutral zone and polished surfaces in complete dentures. J Prosthet Dent 1964;14:854-65. 6. Beresin VE, Schiesser FJ. The neutral zone in complete dentures. J Prosthet Dent 1976;36:356-67. 7. Lott F, Levin B. Flange technique: an anatomic and physiologic approach to increased retention, function, comfort and appearance of dentures. J Prosthet Dent 1966;16:394-413. 8. Miller WP, Monteith B, Heath MR. The effect of variation of the lingual shape of mandibular complete dentures on lingual resistance to lifting forces. Gerodontology 1998;15:113-9. 9. Barrenas L, Odman P. Myodynamic and conventional construction of complete dentures: a comparative study of comfort and function. J Oral Rehabil 1989;16:457-65. 10. Ohkubo C, Hanatini S, Hosoi T, Mizuno Y. Neutral zone approach for denture fabrication for a partial glossectomy patient: a clinical report. J Prosthet Dent 2000;84:390-3. 11. Kokubo Y, Fukushima S, Sato J, Seto K. Arrangement of artificial teeth in the neutral zone after surgical reconstruction of the mandible: a clinical report. J Prosthet Dent 2002;88:125-7. 12. Fahmy FM, Kharat DU. A study of the importance of the neutral zone in complete dentures. J Prosthet Dent 1990;64:459-62. 13. Neill DJ, Glaysher JK. Identifying the denture space. J Oral Rehabil 1982; 9:259-77. 14. Beresin VE, Schiesser FJ. The neutral zone in complete and partial dentures. 2nd ed. St Louis: Mosby; 1978. p. 73-86. 15. Lear CS, Flanagan JB Jr, Moorrees CF. The frequency of deglutition in man. Arch Oral Biol 1965;10:83-100. 16. Eibling DE, Cavo JW Jr. Dysphagia. In: Calhoun K, Eibling DE, Wax MK. Expert guide to otolaryngology. Philadelphia: American College of Physicians; 2001. p. 282.
Noteworthy Abstracts of the Current Literature
17. Shelton RL Jr, Bosma JF, Sheets BV. Tongue, hyoid and larynx displacement in swallow and phonation. J Applied Phys 1960;15:283-8. 18. Karlsson S, Hedegard B. A study of the reproducibility of the functional denture space with a dynamic impression technique. J Prosthet Dent 1979;41:21-5. 19. Fahmi FM. The position of the neutral zone in relation to the alveolar ridge. J Prosthet Dent 1992;67:805-9. 20. Stromberg WR, Hickey JC. Comparison of physiologically and manually formed denture bases. J Prosthet Dent 1965;15:213-30. 21. Atwood DA. The problem of reduction of residual ridges. In: Winkler S. Essentials of complete denture prosthodontics. 2nd ed. St. Louis: Mosby Year Book; 1988. p. 22-38. Reprint requests to: DR JOSEPH E. MAKZOUME´ BADARO, 25 I. MEDAWAR STREET BADARO CENTER BEIRUT 2058-7007 LEBANON FAX: 00961-1-380530 E-MAIL: [email protected] 0022-3913/$30.00 Copyright Ó 2004 by The Editorial Council of The Journal of Prosthetic Dentistry
doi:10.1016/j.prosdent.2004.09.010
Cytotoxicity of denture base resins: Effect of water bath and microwave postpolymerization heat treatments Jorge JH, Giampaolo ET, Vergani CE, Machado AL, Pavarina AC, Carlos IZ. Int J Prosthodont 2004;17:340-4.
Purpose: This study compared the effect of two postpolymerization heat treatments on the cytotoxicity of three denture base resins on L929 cells using 3H-thymidine incorporation and MTT assays. Materials and Methods: Sample disks of Lucitone 550, QC 20, and Acron MC resins were fabricated under aseptic conditions and stored in distilled water at 37°C for 48 hours. Specimens were then divided into three groups: (1) heat treated in microwave oven for 3 minutes at 500 W; (2) heat treated in water bath at 55°C for 60 minutes; and (3) no heat treatment. Eluates were prepared by placing three disks into a sterile glass vial with 9 mL of Eagle’s medium and incubating at 37°C for 24 hours. The cytotoxic effect from the eluates was evaluated using the 3H-thymidine incorporation and MTT assays, which reflect DNA synthesis levels and cell metabolism, respectively. Results: The components leached from the resins were cytotoxic to L929 cells when 3H-thymidine incorporation assay was employed. In contrast, eluates from all resins revealed noncytotoxic effects as measured by MTT assay. For both MTT assay and 3H-thymidine incorporation, the heat treatments did not decrease the cytotoxicity of the materials tested. Conclusion: Resins were graded by 3H-thymidine incorporation assay as slightly cytotoxic and by MTT assay as noncytotoxic. Cytotoxicity of the denture base materials was not influenced by microwave or water bath heat treatment.—Reprinted with permission of Quintessence Publishing.
568
VOLUME 92 NUMBER 6