• discuss the rationale for the use of an apical barrier.
   
• be familiar with the various techniques and materials used to obtain an apical  barrier.
• describe the indications, contraindications, pros, and cons of apical barriers in general, and those made with dentin chips and calcium hydroxide in particular.
• support your use or non use of apical barriers.
• discuss the different treatment options available for the incompletely developed root before the advent of the calcium hydroxide apexification procedure and their drawbacks.
• describe alternative medications and procedures that have been tried for apexification and their clinical success.

TEXT REFERENCES: Pathways of the Pulp; Cohen S and Hargreaves KM, 9th eds. Mosby Co. 2006:869 – 874; Endodontics; Ingle JI Bakland LK and Baumgartner JC, 6th eds. Becker 2008:1336-1339.

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Cvek M, Cleaton-Jones PE, Austin JC, Andreasen JO. Pulp reactions to
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ElDeeb ME, Thuc-Quyen NT, Jensen JR. The dentinal plug: its effect on confining substances to the canal and on the spical seal. J Endodon 1983;9:355-359.

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Lawley G, Schindler W, Walker W, Kolodrubetz D. Evaluation of ultrasonically
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OPTIONAL

*Gollmer L. The use of dentin debris as a root canal filling. Int J Ortho
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Cooke C, & Rowbotham TC.  Root canal therapy in non-vital teeth with open apices. Brit Dent J 108:147-150. 1960.

*Pisanti S. Origin of Calcium in the repair wall after pulp exposure in the dog. J Dent Res 1964;43:641.

*Frank AL. Therapy for the divergent pulpless tooth by continued apical
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Friend, LA. The treatment of immature teeth with non-vital pulps. Brit Endod Soc 1:28-33. 1967.

*Haga CS.  Microscopic measurements of root canal preparations following instrumentation. Brit Endod Soc 1968;2:41.

Steiner, JC, Dow, PR and Cathey, GM. Inducing root end closure of nonvital permanent teeth.  J Dent Child 35:47-54. 1968.

*Heithersay GS. Stimulation of root formation in incompletely developed pulpless teeth. Oral Surg 29:620-630. 1970.

Laws AJ. Condensed calcium hydroxide root filling following partial pulpectomy. New Zeal Dent J 1971;67:161.

Dylewski, JJ. Apical closure of nonvital teeth.  Oral Surg 32:82-89. 1971.

*Erausquin Jorge. Periapical tissue response to the apical plug in root canal treatment. J Dent Res 1972;

Ham J, Patterson SS et al. Induced apical closure of immature pulpless teeth in monkeys. Oral Surg 33:438. 1972.

Winstein and Goldman. Apical hard tissue depositionin adult teeth of monkeys with the use of calcium hydrxide. J Endodon 1974;1

Goldman, M. Root end closure techniques including apexification. DCNA 18:297-308. 1974.

*Klein SH & Levy BA. Histologic evaluation of induced apical closure of a human pulpless tooth. Oral Surg 38:954-959. 1974.

Seidler B. Remission of pain of acute apical periodontitis after blockage of apex with filings: case report. J Endodon 1976; 2: ppgs?

*Walton RE. Histologic evaluation of different methods of enlarging the pulp canal space. J Endodon 1976;2:304-311.

Heithersay, GS. Calcium hydroxide in the treatment of pulpless teeth with associated pathologhy. J Brit Endo Soc 8:74. 1975.

Barker BCW, Mayne JR. Some unusual cases of apexification subsequant to trauma. Oral Surg 39:144-150. 1975.

Cvek ML,  Hollender L et al. Treatment of non-vital permanent incisors with calcium  hydroxide. VI. A clinical, microbiological, and radiological evaluation of treatment in one sitting of teeth with mature or immature root. Odont Revy 27:97.1976.

Piekoff, MD and Trott, JR. Apexification: report of a case. J Endodon 2:182-185. 1976.

Nevins, A et al.  Induction of hard tissue into pulpless open apex teeth using collagen-calcium phosphate gel.  J Endodon 4:76-81. 1978.

Adams et al. The effect of the apical dentinal plug on broken endodontic instruments. J Endodon !979;5:121-128.

Holland RV, deSouza V et al. A histologic study of the effect of calcium hydroxide in the treatment of pulpless teeth of dogs. J Brit Endo Soc 12:15-23. 1979.

Citrome GP, Kaminski EJ, Heuer MA.  A comparative study of tooth apexification in the dog.  J Endodon 5:290-297. 1979.

*Holland R, Souza V, Nery M et al. Apical hard-tissue deposition in adult teeth of monkeys with the use of calcium hydroxide. Aus Dent J 1980.

Chawla HS, Tewari A et al. A study of apexification without a catalyst paste. J Dent Child:431-434. 1980.

Das, S. Apexification in a non-vital tooth by control of infection. JADA 100:880-881. 1980.

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Smith, G. N. and S. Woods (1983). "Organic iodine: a substitute for BaSO4 in apexification procedures." Journal of Endodontics 9(2): 153 - 155.

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*Lieberman J, Trowbridge H.  Apical closure of nonvital permanent incisor teeth where no treatment was performed.  J Endodon 9:257-260. 1983.

Schlindler, WG and Walker, WW. Continued root development after apexification of an immature tooth with dens invaginatus. J Endodon 9(10). 1983.

Rossmeisl R, Reader A, Melfi R, Marquard,J.  A study of freeze-dried (lyophilized) dentin used as an apical barrier in adult monkey teeth. Oral Surg 1983;53:303-310.

Pitts DL, Jones JE, Oswald RJ. A histological comparison of calciumhydroxide plugs and dentin plugs used for the control of gutta-percha root canal filling material. J Endodon 1984;10:283-293.

Smith JW, Leeb IJ, Torney DL. A comparison of calcium hydroxide and barium hydroxide as agents for inducing apical closure. J Endodon 10:64-70. 1984.

Leonardo et al. Immediate root canal filling: the use of cytophylactic substances and noncytotoxic solutions. J Endodon 1984;10:1-7.

Webber, RT. Apexogenesis versus Apexification. DCNA 28:669-697. 1984.

Krell KV, Madison S. The use of the Messing gun in placing calcium hydroxide powder. J Endodon 11:233-234. 1985.

Feiglin, B. Differences in apex formation during apexification with calcium hydroxide.  Endo Dent Traumatol 1:195-199. 1985.

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Safavi K, Horsted P, Pascon EA, Langeland K. Biological evaluation of the apical dentin chip plug. J Endodon 1985;11:18-24.

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Torabinejad M, Owen R, Danforth RA, Howell RE. Periapical tissue responses to dentin and vitreous carbon plugs in apical perforations of dogs' teeth. Endo Dent Traum 1986;1:17-21.

Chawla, HS. Apical closure in a nonvital permanent tooth using one calcium hydroxide dressing. J Dent Child Jan/Feb 1986.

Anthony, D. R. (1986). "Apexification during active orthodontic movement." Journal of Endodontics 12(9): 419 - 421.

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Patterson SM, Patterson SS, Newton CW, Kafrawy AH. The effect of an apical
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*Yates JA. Barrier formation time in non-vital teeth with open apices. Int Endo J  21:313-319. 1988.

*Beeler WJ, Marshall FJ, Brown AC. The permeability of apical barriers. J Endodon 1989;15:422-426.

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*Klier DJ, Barr ES. A study of endodontically apexified teeth. Endod Dent Traumatol 7:112-117. 1991.

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*Scott AC, Vire DE. An evaluation of the ability of a dentin plug to control extrusion of thermoplasticized gutta-percha. J Endodon 1992; 18:52-57.

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Leonardo M, de Silva L et al. Histological evaluation of therapy using a calcium hydroxide dressing for teeth with incompletely formed apices and periapical lesions. J Endodon 19:348-352. 1993.

Schmalz G and Schweikl H. Characterization of an in vitro dentin barrier test using a standard toxicant. J Endodon 1994;20:592-594.

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