title: Fracture resistance of five pin-retained core build-up materials on teeth with and without extracoronal preparation.
abstract: Core build-ups should provide satisfactory strength and resistance to fracture both before and after crown preparation. This paper examines the resistance to fracture of core build-ups in different materials and the fracture resistance of core build-ups when these have been reduced for full crown preparation. Standardized core build-ups were made on groups of extracted molar teeth of similar size, with 10 teeth per group. Three resin-composite (prisma APH: Dentsply, Weybridge, UK; Ti-Core, Essential Dental Systems, NJ, US and Coradent, Vivadent, Liechtenstein), one cermet (Ketac-Silver, ESPE GmbH, Seefeld, Germany) and one amalgam material (Duralloy, Degussa Ltd, Cheshire, UK). These specimens were subjected to compressive force on a universal testing machine and the force at fracture noted. Standardized full crown preparations were made on a further five groups of core build-up specimens using the same materials as above. These prepared specimens were subjected to compressive force on a universal testing machine and the force to fracture noted. The results indicated that amalgam core build-ups demonstrated higher fracture resistance than the other materials examined. There was a general decrease in the fracture strength of the specimens following crown preparation, with the teeth restored with the amalgam core build-ups showing a greater percentage reduction in fracture strength than the other materials tested. Prepared core build-ups in a hybrid composite material provided the highest fracture resistance. The cermet material used provided the lowest resistance to fracture in both the core build-up and crown preparation specimens. In terms of fracture resistance, no advantage was apparent in using the two composite materials designated as being specifically appropriate for core build-ups.
authors.affiliation: University of Birmingham, School of Dentistry, St Chad's Queensway, Birmingham B4 6NN, United Kingdom.
authors.forename: F J
authors.initials: FJ
authors.lastname: Burke
authors.forename: A G
authors.initials: AG
authors.lastname: Shaglouf
authors.forename: E C
authors.initials: EC
authors.lastname: Combe
authors.forename: N H
authors.initials: NH
authors.lastname: Wilson
mesh_terms: D000704:Analysis of Variance; D016722:Cermet Cements / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003442:Crowns; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003737:Dental Cavity Preparation / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry*; D003772:Dental Pins; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008963:Molar; D011176:Post and Core Technique; D019279:Resin Cements / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry; D019231:Tooth Preparation, Prosthodontic
chemical_list: D016722:Cermet Cements; D003188:Composite Resins; C400043:Coradent; D003722:Dental Alloys; D003764:Dental Materials; D019279:Resin Cements; C072650:Duralloy; C073466:Prisma APH; C079578:Ti-Core composite resin; D012834:Silver; D003723:Dental Amalgam; D014025:Titanium