The effect of thermal change on various dowel-and-core restorative materials.
BACKGROUND
Severe thermal stresses caused by food-induced temperature changes may result in dowel-and-core failure.


OBJECTIVE
This study investigated the influence of thermal stresses on various combinations of dowel-and-core materials of a restored endodontically treated incisor.


METHODS
A 2-dimensional finite element model was constructed in a labiolingual cross-sectional view of a maxillary central incisor, a dowel, a core, and the supporting tissues to investigate thermal stress distribution. Four combinations of dowel-and-core materials were used: (1) gold/gold, (2) stainless steel/resin composite, (3) stainless steel/amalgam, and (4) carbon fiber-reinforced composite/resin composite. For thermal analysis, a cold irritant (0 degrees C) was applied on the outer surface of a metal-ceramic crown for 7 seconds.


RESULTS
The metal dowel and core generated lower thermal stresses in the restorations and dentin than the nonmetallic dowel and cores.


CONCLUSIONS
Stress level is closely related to the degree of thermal gradient. The nonmetallic dowel and cores generated greater thermal stresses than metal dowel and cores.
Yang
H S
HS
College of Dentistry, Chonnam National University, Kwangju, Korea.
Lang
L A
LA
Guckes
A D
AD
Felton
D A
DA
D001831:Body Temperature / Q000502:physiology; D002244:Carbon / Q000737:chemistry; D000077482:Carbon Fiber; D003080:Cold Temperature; D003188:Composite Resins / Q000737:chemistry; D003442:Crowns; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003804:Dentin / Q000502:physiology; D020342:Finite Element Analysis; D006047:Gold Alloys / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D007180:Incisor; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008954:Models, Biological; D011176:Post and Core Technique; D012390:Root Canal Therapy; D013193:Stainless Steel / Q000737:chemistry; D013223:Statistics as Topic; D013696:Temperature; D013816:Thermodynamics; D015036:Zinc Phosphate Cement / Q000737:chemistry
D000077482:Carbon Fiber; D003188:Composite Resins; D003722:Dental Alloys; D003764:Dental Materials; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D013193:Stainless Steel; D002244:Carbon; D015036:Zinc Phosphate Cement; D003723:Dental Amalgam