Ceramic Crown Margin Curvatures’ Effect on Fracture Strength -

Despite the high fracture strength of modern dental core ceramics, fracture is a common cause of failure in clinical trials. Fracture origins are typically in the crown margin in the appoximal region where the margin curves upwards. The scientific evidence for optimal marginal design of preparation is limited. The aim was to use a clinically relevant test method to evaluate the effect on strength of the cervical margin’s curvature of ceramic crowns.

Simulation of clinical fractures for three different all-ceramic crowns. -

Comparison of fracture strength and fracture modes of different all-ceramic crown systems is not straightforward. Established methods for reliable testing of all-ceramic crowns are not currently available. Published in-vitro tests rarely simulate clinical failure modes and are therefore unsuited to distinguish between the materials. The in-vivo trials usually lack assessment of failure modes. Fractographic analyses show that clinical crowns usually fail from cracks initiating in the cervical margins, whereas in-vitro specimens fail from contact damage at the occlusal loading point. The aim of this study was to compare three all-ceramic systems using a clinically relevant test method that is able to simulate clinical failure modes.

NIOM at NTF Landsmøte and Rikstämman, 2013 -

NIOM scientists were invited to the national dental conventions in Sweden and Norway this autumn. You can here read the conclusions of the lectures given on bulk-fill materials, nano-materials, safety of tooth bleaching, and quality of custom-made dental restorations imported from overseas and made at national laboratories.

Experimental investigation of the effect of surface roughness on bone-cement-implant shear bond strength. -

Debonding of cemented bone implants is regarded as a major contributor to complications. The relationship between shear bond strength and surface roughness has been investigated, however there are inconsistencies in the trends reported in different studies.

Clinically relevant evaluation of fracture strength of all-ceramic crowns -

Determination of fracture strength of different all-ceramic dental crown systems is not straight forward. Most in vitrotest methods induce contact damage at the loading point (crunch the crown-tests). Clinical failures, on the other hand, usually originate from cracks in the cervical margins. The aim of this study was to compare three all-ceramic systems using a test method that mimic clinical failure modes.