J Korean Acad Conserv Dent.  2002 Jul;27(4):389-393. 10.5395/JKACD.2002.27.4.389.

The effect of the endodontic access cavity on the marginal leakage of crowns

• Kim E
• Chung J
• Kim Y

• KMID: 1987294
• DOI: http://doi.org/10.5395/JKACD.2002.27.4.389

Abstract

The marginal integrity of the crown can be broken during endodontic access cavity preparation due to the vibration of burs. Therefore, the purpose of this study was to evaluate the effect of endodontic access cavity preparation on the marginal leakage of full veneer gold crowns. 24 intact molars were mounted in acrylic resin blocks and prepared for crowns by a restorative dentist and crowns were cast with gold alloy. 20 Crowns were cemented with glass ionomer cement and 2 crowns were not cemented for positive control. 200 thermo-cycles from 5degrees C to 50degrees C with a travel time of 20s were completed. Then samples were randomly divided into 2 experimental groups of 9 each. Endodontic access preparation and zinc-oxide eugenol temporary fillings were done in Group 1. Teeth in Group 2 were not treated. Samples were coated with 2 layers of nail varnish and were immersed in 1% methylene blue dye for 20 hrs. Endodontic access was prepared in 2 samples, which were coated with nail varnish on all surfaces for negative control. After washing in running water, gold crowns were cut with a #330 bur. Four buccolingual sections, 2 mm apart, were cut from the central section of each tooth and were examined and scored under the microscope for dye leakage. Score 1: leakage to the cervical 1/3 of the axial wall, Score 2: leakage to the middle 1/3 of the axial wall, Score 3: leakage to the coronal 1/3 of the axial wall, Score 4: leakage to the occlusal surface. The median value for Group 1 is 4 and for Group 2 is 2. The result of this study showed that samples in Group 1 leaked more than those in Group 2. This finding was significant(P<0.001).

Keyword

Coronal leakage; Marginal integrity; Access cavity

MeSH Terms

Acrylic Resins
Alloys
Crowns
Dentists
Eugenol
Glass Ionomer Cements
Humans
Methylene Blue
Molar
Nails
Paint
Running
Silicon Dioxide
Tooth
Vibration
Water
Acrylic Resins
Alloys
Eugenol
Glass Ionomer Cements
Methylene Blue
Silicon Dioxide
Water

Figure

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  Fig. 1 Schematic drawing of section for leakage observation.

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  Fig. 2 Scoring criteria of dye leakage(×25).

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  Fig. 3 Leakage of group I sample scoring 4 which is leakage to the occlusal surface(×25).

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  Fig. 4 Leakage of group II sample scoring 2 which is leakage to the middle 1/3 of the axial wall(×25).

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