Biomaterial Database

Load fatigue of teeth with different ferrule lengths, restored with fiber posts, composite resin cores, and all-ceramic crowns. 2009

Polly S Ma, and Jack I Nicholls, and Thomas Junge, and Keith M Phillips

Private practice, Edmonds, WA, USA. pscma@yahoo.com

BACKGROUND There is no evidence to suggest that the ferrule length needed for an all-ceramic crown is different from that needed for a cast metal or metal ceramic crown. OBJECTIVE The purpose of this study was to relate different ferrule lengths with the number of fatigue cycles needed for failure of the crown cement for an all-ceramic crown cemented with a resin cement. METHODS Fifteen maxillary central incisors were divided into 3 groups (n=5), with ferrules of 0.0 mm (no-ferrule group), 0.5 mm (0.5-mm ferrule group), and 1.0 mm (1.0-mm ferrule group), respectively. Each tooth was restored with a 0.050-inch glass-filled composite post (ParaPost FiberWhite) and a composite resin core (ParaCore). The posts were cemented with resin cement (ParaPost Cement), and the composite resin cores were bonded to dentin using a dentin bonding agent (ParaPost Cement, Conditioner A & B). Each specimen was prepared with a 7-mm total preparation height, a 1.5-mm lingual axial wall, and a 1.0-mm shoulder around the tooth. The crowns for all specimens were pressed with a pressable ceramic material (IPS Empress 2) and cemented with resin cement (Variolink II). A 6-kg cyclic test load was applied to each specimen at 135 degrees to the long axis of the tooth. The independent variable measured was the number of load fatigue cycles required for failure of the crown cement. The data were subjected to the Kruskal-Wallis test to detect overall significance and the Mann-Whitney U test for pairwise comparisons with Bonferroni correction (alpha=.017). RESULTS The mean (SD) number of cycles to failure for each group was: no-ferrule group, 213 (317); 0.5-mm ferrule group, 155,137 (68,991); and 1.0-mm ferrule group, 262,872 (21,432). None of the specimens in the 1.0-mm ferrule group failed. Significant differences were found between the no-ferrule group and the 0.5-mm ferrule group, and the no-ferrule group and the 1.0-mm ferrule group (P<.017), but not between the 0.5-mm ferrule group and the 1.0-mm ferrule group (P>.017). CONCLUSIONS Specimens with a 0.0-mm ferrule survived few fatigue cycles despite the fact that both the post and crown were bonded with resin cement. Teeth with a 0.5-mm ferrule showed a significant increase in the number of fatigue cycles over the 0.0-mm group, whereas teeth with the 1.0-mm ferrule exhibited a significantly higher fatigue cycle count over the 0.0-mm but not the 0.5-mm group.

UI	MeSH Term	Description	Entries
D007180	Incisor	Any of the eight frontal teeth (four maxillary and four mandibular) having a sharp incisal edge for cutting food and a single root, which occurs in man both as a deciduous and a permanent tooth. (Jablonski, Dictionary of Dentistry, 1992, p820)	Incisors
D008422	Materials Testing	The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.	Biocompatibility Testing,Biocompatible Materials Testing,Hemocompatibility Testing,Testing, Biocompatible Materials,Testing, Hemocompatible Materials,Hemocompatibility Testings,Hemocompatible Materials Testing,Materials Testing, Biocompatible,Materials Testing, Hemocompatible,Testing, Biocompatibility,Testing, Hemocompatibility,Testing, Materials,Testings, Biocompatibility
D008437	Maxilla	One of a pair of irregularly shaped bones that form the upper jaw. A maxillary bone provides tooth sockets for the superior teeth, forms part of the ORBIT, and contains the MAXILLARY SINUS.	Maxillae,Maxillary Bone,Bone, Maxillary,Bones, Maxillary,Maxillary Bones,Maxillas
D011176	Post and Core Technique	Use of a metal casting, usually with a post in the pulp or root canal, designed to support and retain an artificial crown.	Dental Dowels,Dental Dowel,Dowel, Dental,Dowels, Dental,Post Technic,Post Technique,Post and Core Technic,Post-Core Technic,Post Technics,Post Techniques,Post-Core Technics,Technic, Post,Technic, Post-Core,Technics, Post,Technics, Post-Core,Technique, Post,Techniques, Post
D003188	Composite Resins	Synthetic resins, containing an inert filler, that are widely used in dentistry.	Composite Resin,Resin, Composite,Resins, Composite
D003442	Crowns	A prosthetic restoration that reproduces the entire surface anatomy of the visible natural crown of a tooth. It may be partial (covering three or more surfaces of a tooth) or complete (covering all surfaces). It is made of gold or other metal, porcelain, or resin.	Dental Crowns,Crown, Dental,Crowns, Dental,Dental Crown,Crown
D003738	Dental Cements	Substances used to bond COMPOSITE RESINS to DENTAL ENAMEL and DENTIN. These bonding or luting agents are used in restorative dentistry, ROOT CANAL THERAPY; PROSTHODONTICS; and ORTHODONTICS.	Dental Adhesives,Luting Agents,Orthodontic Adhesives,Cement, Dental,Cements, Dental,Dental Cement,Adhesive, Dental,Adhesive, Orthodontic,Adhesives, Dental,Adhesives, Orthodontic,Dental Adhesive,Luting Agent,Orthodontic Adhesive
D003793	Dental Restoration, Permanent	A restoration designed to remain in service for not less than 20 to 30 years, usually made of gold casting, cohesive gold, or amalgam. (Jablonski, Dictionary of Dentistry, 1992)	Dental Fillings, Permanent,Dental Filling, Permanent,Dental Permanent Filling,Dental Permanent Fillings,Dental Restorations, Permanent,Filling, Dental Permanent,Filling, Permanent Dental,Fillings, Dental Permanent,Fillings, Permanent Dental,Permanent Dental Filling,Permanent Dental Fillings,Permanent Dental Restoration,Permanent Dental Restorations,Permanent Filling, Dental,Permanent Fillings, Dental,Restoration, Permanent Dental,Restorations, Permanent Dental
D003799	Dental Stress Analysis	The description and measurement of the various factors that produce physical stress upon dental restorations, prostheses, or appliances, materials associated with them, or the natural oral structures.	Analyses, Dental Stress,Analysis, Dental Stress,Stress Analyses, Dental,Stress Analysis, Dental,Dental Stress Analyses
D005898	Glass	Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.