Effect of pontic framework design on the fracture resistance of implant-supported all-ceramic fixed partial dentures

Abstract

Objective:The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs.Material and Methods:Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10). Afterwards, specimens were centrally loaded on the pontics until failure with a universal testing machine. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests at 5% significance level.Results:The fracture resistance values of all-ceramic fixed partial dentures designed with biconvex, convex or concave pontics were 349.71, 438.20 and 300.78 N, respectively. There were no statistically significant differences between the fracture resistances of the groups (p>0.05), except for convex and concave groups (p<0.05 and p=0.009, respectively).Conclusions:Convex design showed the best mechanical properties as demonstrated by the high values of fracture resistance.

Translucency of monolithic and core zirconia after hydrothermal aging

“…[ 11–13 ] Recently, it has become possible to fabricate all-ceramic restorations with high resistant to fracture, even when they are used in the posterior region, by using ZrO 2 -based materials due to its good mechanical properties and tooth-like appearance. [ 14 , 15 ] This ZrO 2 has many advantages over the porcelain-veneered ZrO 2 copings in that no liability of veneering fracture or chipping as it is already absent, beside the high strength that is reported to be comparable to previous all-ceramic crowns as well as a patent shading system that enables high esthetic matching. All these advantages allow less axial walls and occlusal reduction in tooth structure to be done.…”

Op kronen en bruggen uitgeoefende krachten en het weerstaan daarvan 2. Mechanische belastbaarheid

“…De occlusaal convexe en cervicaal concave vorm vertoonde de grootste mechanische belastbaarheid en het verschil ten opzichte van de occlusaal concave en cervicaal convexe vorm was statistisch significant (afb. 3) (Inan et al, 2009). Met een ander laboratoriumonderzoek werd aangetoond dat brugdelen van keramiekbruggen ter plaatse van connectorgebieden beter met een ronde vorm in elkaar kunnen overgaan dan met een spitse vorm (afb.…”

Implant Restoration Materials: An Overview

“…The zirconia substructure with a flexural strength of 1,000 MPa remains in tact but the failure of the layering porcelain ultimately causes a failure of the restoration. 33 With monolithic lithium disilicate, the force of mastication is applied on a 360 to 400 MPa material. This strength is homogenous throughout the entire restoration.…”

“…Several tests have demonstrated that the monolithic lithium disilicate is incredibly durable and that the zirconia veneered restorations fail with less load and fewer chewing cycles. 33 However, esthetic outcome of such machinable blocks may be a concern. In a study, regardless of the fabrication method the crowns were esthetically acceptable in all the patients.…”