title: Survival rate, fracture strength and failure mode of ceramic implant abutments after chewing simulation.
abstract: The aim of this study was to compare titanium-reinforced ZrO(2) and pure Al(2)O(3) abutments regarding their outcome after chewing simulation and static loading. Forty-eight standard diameter implants with an external hexagon were divided into three groups of 16 implants each and restored with three different types of abutments (group A: ZrO(2) abutments with titanium inserts; group B: Al(2)O(3) abutments; group C: titanium abutments). All abutments were fixated on the implants with gold-alloy screws at 32 Ncm torque, and metal crowns were adhesively cemented onto the abutments. The specimens were exposed to 1.2 million cycles in a chewing simulator. Surviving specimens were subsequently loaded until fracture in a static testing device. Fracture loads (N) and fracture modes were recorded. A Wilcoxon Rank test to compare fracture loads among the three groups and a Fisher exact test to detect group differences in fracture modes were used for statistical evaluation (P < 0.05). All specimens but one of group B survived chewing simulation. No screw loosening occurred. The median fracture loads (+/-s.d.) were as follows: group A, 294 N (+/-53); group B, 239 N (+/-83), and group C, 324 N (+/-85). The smaller fracture loads in group B were statistically significant. The use of pure Al(2)O(3) abutments resulted in significantly more abutment fractures. It is proposed that titanium-reinforced ZrO(2) abutments perform similar to metal abutments, and can therefore be recommended as an aesthetic alternative for the restoration of single implants in the anterior region. All-ceramic abutments made of Al(2)O(3) possess less favourable properties.
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Hospital, Hugstetter Strasse 55, 79106 Freiburg, Germany. frank.butz@uniklinik-freiburg.de
authors.forename: F
authors.initials: F
authors.lastname: Butz
authors.forename: G
authors.initials: G
authors.lastname: Heydecke
authors.forename: M
authors.initials: M
authors.lastname: Okutan
authors.forename: J R
authors.initials: JR
authors.lastname: Strub
mesh_terms: D000044:Dental Abutments; D015921:Dental Implants; D003776:Dental Porcelain; D019232:Dental Restoration Failure; D006801:Humans; D008409:Mastication; D008422:Materials Testing; D011474:Prosthesis Design; D011475:Prosthesis Failure
chemical_list: D015921:Dental Implants; D003776:Dental Porcelain