摘要

To evaluate debonding mechanism of zirconia and lithium disilicate cemented to dentin mimicking what could occur in a clinical setting. A null hypothesis of no difference in tensile bond strength between groups of zirconia and lithium disilicate cemented with resin cements was also tested. Zirconia rods (n = 100) were randomly assigned to two different surface treatment groups; air borne particle abrasion and hot etching by potassium hydrogen difluoride (KHF2). Lithium disilicate rods (n = 50) were surface etched by hydrofluoric acid (HF). Five different dual cure resin cements were used for cementing rods to bovine dentin. Ten rods of each test group were cemented with each cement. Test specimens were thermocycled before tensile bond strength testing. Fracture morphology was visualized by light microscope. Mean surface roughness (Sa value) was calculated for randomly selected rods. Cohesive fracture in cement was the most frequent observed fracture morphology. Combination of adhesive and cohesive fractures were second most common. Fracture characterized as an adhesive between rod and cement was not observed for KHF2 etched zirconia. Highest mean tensile bond strength was observed when cementing air borne particle abraded zirconia with Variolink Esthetic (Ivoclar Vivadent). All surface treatments resulted in Sa values that were significant different from each other. The number of cohesive cement fractures observed suggested that the cement was the weakest link in bonding of zirconia and lithium disilicate.

关键词

resin cement;ceramics;Zirconia

授权许可

© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

图表

Design of ceramic rod. The illustration shows the dimensions in mm and a copy of the computer aided design (CAD).

Experimental design of tensile bond strength test. A metallic jig enclosed the ceramic rod at the notch in the circumference for adequate grip. The rod was cemented onto the dentin surface of bovine tooth embedded in epoxy resin.

Examples of fracture morphology observed in light microscope (diameter 5 mm). 1: combination of cohesive fracture in cement and adhesive fracture between cement-zirconia; 2: combination of cohesive fracture in dentin and adhesive fracture between cement-dentin and cement-zirconia; 3: combination of cohesive fracture in dentin and cement, and adhesive fracture cement-zirconia.

Mean tensile bond strength and standard deviation. Zir A: air borne particle abraded zirconia; Zir E: KHF2 etched zirconia; LDS: hydrofluorid acid etched lithium disilicate. Different lowercase letters illustrate significant difference (p < .05) between Zir A, Zir E, and LDS for each cement. Different uppercase letters illustrate significant differences (p < .05) between cements for each rod material.

Representative SEM images of air borne particle abraded zirconia (a), KHF2 etched zirconia (b), and hydrofluoric acid etched lithium disilicate (c). Bar represents 20 μm.

通讯作者

Mina Aker Sagen.Institute of Clinical Dentistry, University of Oslo, Oslo, Norway.m.a.sagen@odont.uio.no

推荐引用方式

Mina Aker Sagen,Ketil Kvam,Eystein Ivar Ruyter,Hans Jacob Rønold. Debonding mechanism of zirconia and lithium disilicate resin cemented to dentin. Acta Biomaterialia Odontologica Scandinavica ,Vol.5, Issue 1(2019)

您觉得这篇文章对您有帮助吗？

分享和收藏

0

是否收藏?

参考文献