Abstract

Introduction: Work of fracture (WOE) is a method of analysis of the toughness or resilience of a bracket bonding system. It is an indication of a bracket bonding systems ability to withstand forces in the mouth below the force at which failure occurs. Work of fracture gives an indication of how much abuse the bracket/bonding system can withstand and still maintain an adequate adhesion to the tooth surface. This analysis incorporates shear bond strength and displacement and is determined in part by the elasticity and resilience of the specimen being studied.

Materials and Methods: One hundred and eighty bovine teeth were collected. Sixty of the teeth were direct bonded with titanium brackets, sixty with monocrystalline ceramic brackets, and sixty with polycrystalline ceramic brackets. Each bracket group of sixty was subdivided into two groups of thirty and each of these subgroups was then bonded with either Gren Gloo or Transbond XT. After bonding, the specimens were debonded with a newly developed Instron-like machine.

Results: Titanium brackets bonded with Gren Gloo exhibit higher displacement, shear bond strength (SBS) and work of fracture than all other bracket types (p < 0.001). Titanium brackets with Transbond had higher displacement (p < 0.001) then any ceramic bracket/bonding system combinations, and higher WOE then all ceramic bracket/bonding system combinations (p < 0.001) except compared to Ice with Gren Gloo (IGG). Ice brackets with Gren Gloo had higher SBS and WOF than any other ceramic bracket/bonding system combination but in relation to displacement it was only significantly higher than the Ice brackets bonded with Transbond. Gren Gloo generally exhibited higher WOF, and SBS compared to Transbond. Titanium brackets exhibited higher displacement, WOF and SBS in comparison to the other bracket types.

Conclusions: Titanium with Gren Gloo had much higher mean WOF mean than any other bracket/bonding system combination and Ice with Gren Gloo had higher mean WOF compared to the other ceramic bracket/bonding systems. These results are significant because the increased ability of a bracket/bonding system to absorb energy may increase the longevity of that bracket/bonding system in-vivo.

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Dentistry

School

Graduate Studies

First Advisor

Craig A. Andreiko

Second Advisor

Dan A. Flores

Third Advisor

V. Leroy Leggitt

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2010

Date (Title Page)

9-2010

Language

English

Library of Congress/MESH Subject Headings

Orthodontic Brackets; Tooth Fractures; Dental Bonding -- methods: Dental Cements -- analysis: Materials Testing; Shear Strength; Equipment Failure Analysis; Dental Stress Analysis.

Type

Thesis

Page Count

xii; 69

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

Download

Share

COinS