Effect of Axial Wall Height and Total Occlusal Convergence on Retention of Lithium Disilicate Adhesively Bonded to Lithium Disilicate
Abstract
Statement of Problem: Currently, no published data exists to provide clinical guidance on decisions relative to axial wall height and degree of occlusal convergence regarding crowns that can be bonded, instead of merely luted, to a lithium disilicate implant supported custom abutment. Purpose: The purpose of this study was to quantify the effect that axial wall height and degrees of total occlusal convergence had on the resistance to dislodgement of lithium disilicate crowns bonded to lithium disilicate custom implant abutments. Material and Methods: Eight groups of ten lithium disilicate (IPS emax, Ivoclar Vivadent, Inc., Amherst, NY) crown and abutment pairs (n=10) were fabricated. Each group differed in axial wall height and total occlusal convergence of the abutment and corresponding crown. Lithium disilicate crowns were adhesively bonded to lithium disilicate abutments using the Panavia V5 (Kuraray North America, Houston, TX) resin cement system. Following cementation, samples were artificially aged, mounted into the Instron Universal Testing Machine (Instron, Norwood, MA) and forces directed at 45 degrees to the long axis of the sample were applied to each sample to failure (fracture or debonding). The mode of failure and load at which failure occurred was recorded. Results: Mode of failure for 98.73% (78 of 79) samples across all groups was fracture of ceramic as opposed to debonding alone. Conclusions: Results of this in vitro study indicates that bonded crown and abutment specimens will not result in dislodged crowns due to lack of resistance form regardless of axial wall height or TOC. Even a single millimeter of axial wall height at 15 degrees TOC resulted in a crown that remained bonded to its abutment until such a high level of force was reached that cohesive failure occurred by means of fractured ceramic (at more than double the force from average human bite-force) rather than failure of the resin bond.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 2020
- Accession Number
- AD1182678
Entities
People
- Troy M Decker
Organizations
- Uniformed Services University of the Health Sciences