title: Fracture strength of teeth restored with ceramic inlays and overlays.
abstract: This study evaluated the fracture strength of teeth restored with bonded ceramic inlays and overlays compared to sound teeth. Thirty sound human maxillary premolars were assigned to 3 groups: 1- sound/unprepared (control); 2- inlays and 3- overlays. The inlay cavity design was Class II MOD preparation with an occlusal width of 1/2 of the intercuspal distance. The overlay cavity design was similar to that of the inlay group, except for buccal and palatal cusp coverage The inlay and overlay groups were restored with feldspathic porcelain bonded with adhesive cement. The specimens were subjected to a compressive load until fracture. Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. The fracture strength means (KN) were: Sound/unprepared group = 1.17, Inlay group= 1.17, and Overlay group = 1.14. There were no statistically significant differences (p>0.05) among the groups. For inlays and overlays, the predominant fracture mode involved fragments of one cusp (70% of simple fractures). The fracture strength of teeth restored with inlay and overlay ceramics with cusp coverage was similar to that of intact teeth.
authors.affiliation: Department of Restorative Dentistry, Dental School, University of São Paulo, São Paulo, SP, Brazil. sesma@usp.br
authors.forename: Susana
authors.initials: S
authors.lastname: Morimoto
authors.forename: Glauco Fioranelli
authors.initials: GF
authors.lastname: Vieira
authors.forename: Carlos Martins
authors.initials: CM
authors.lastname: Agra
authors.forename: Newton
authors.initials: N
authors.lastname: Sesma
authors.forename: Carlos
authors.initials: C
authors.lastname: Gil
mesh_terms: D001641:Bicuspid; D003737:Dental Cavity Preparation; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D006801:Humans; D007284:Inlays; D013314:Stress, Mechanical; D019228:Tooth Crown / Q000502:physiology; D014082:Tooth Fractures / Q000517:prevention & control*
chemical_list: D003776:Dental Porcelain