The effect of surface characteristics and antimicrobial agents on the growth of biofilms on

238 Pages·2015·4.49 MB·English

by  Shaneel Shastri

ResearchOnline@JCU

This file is part of the following reference:

Shastri, Shaneel (2015) The effect of surface
characteristics and antimicrobial agents on the growth of
biofilms on orthodontic mini-screw implants. DClinDent
thesis, James Cook University.

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The effect of surface
characteristics and antimicrobial
agents on the growth of biofilms
on Orthodontic mini-screw
implants

Thesis for partial fulfilment of the requirements for a Doctor of
Clinical Dentistry in Orthodontics.

Shaneel Shastri
The effect of surface
characteristics and antimicrobial
agents on the growth of biofilms
on Orthodontic mini-screw
implants

Thesis for partial fulfilment of the requirements for a Doctor of
Clinical Dentistry in Orthodontics.

Shaneel Shastri

College of Medicine and Dentistry | Department of Orthodontics

Submitted:.March 2015
Table of contents

List of abbreviations ....................................................................................... 7
List of figures .................................................................................................. 8
List of tables ................................................................................................. 10
Declaration................................................................................................... 11
Declaration of ethics .................................................................................... 12
Acknowledgement ....................................................................................... 13
Statement on the contribution of others ..................................................... 14
Abstract ....................................................................................................... 15
Chapter 1 - Literature review ................................................................................ 19
1.1 Introduction ......................................................................................... 20
1.2 The concept of absolute anchorage ....................................................... 25
1.3 The development of TADS in orthodontics ............................................. 29

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1.4 The orthodontic mini screw implant ...................................................... 42
1.4.1 Definitions and classification ..................................................... 46
1.4.2 Indirect and direct anchorage ................................................... 48
1.4.3 Types and properties ................................................................. 50
1.4.4 Biocompatibility ........................................................................ 52
1.4.5 Osseointegration of OMSI ......................................................... 54
1.4.6 Thread and body design ............................................................ 56
1.4.7 Bone quality and OMSI stability ................................................ 62
1.4.8 Length of implants..................................................................... 67
1.4.9 Diameter of implants................................................................. 72
1.4.10 Head design ............................................................................. 74
1.4.11 Diagnostic imaging for OMSIs .................................................. 76

1.5 Clinical factors regarding OMSI .............................................................. 79
1.5.1 Loading and anchorage considerations ..................................... 83
1.5.2 Clinical factors for OMSI survival ............................................... 85
1.5.3 Complications of OMSI .............................................................. 89
1.5.4 Current success and failure rates .............................................. 92

1.6 Biofilm formation on dental implants ..................................................... 95
1.7 Surface roughness and the effect of biofilm formation .......................... 98
1.8 Antimicrobial agents on orthodontic biofilms ...................................... 101

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Chapter 2 - Significance and aims of study .......................................................... 105
2.1 Significance .......................................................................................... 106
2.2 Aims ..................................................................................................... 108
Chapter 3 - Materials and method ...................................................................... 109
3.1 Materials .............................................................................................. 110
3.2 Surface roughness ................................................................................ 111
3.3 Surface morphology ............................................................................. 114
3.4 Biofilm growth on implant surfaces ...................................................... 115
3.5 Statistical analysis ................................................................................ 122
Chapter 4 - Results .............................................................................................. 123
4.1 Summary of OMSI groups used ............................................................ 124
4.2 SEM qualitative analysis ....................................................................... 125
4.3 Surface roughness ................................................................................ 130
4.4 Surface roughness – Statistical Analysis ............................................... 135
4.5 Bacterial growth on implant groups ..................................................... 138
4.6 Bacterial growth – Statistical analysis ................................................... 144
4.7 Bacterial growth – Antimicrobial agents............................................... 148

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Chapter 5 - Discussion ......................................................................................... 153

Chapter 6 - Conclusions ....................................................................................... 173

Chapter 7 - Appendices ....................................................................................... 177
7.1 Appendix A: Ethics approval ............................................................... 178
7.2 Appendix B: Ethics information form.................................................... 179
7.3 Appendix B: Ethics consent form .......................................................... 180
7.4 Appendix C: Roughness data ................................................................ 181
7.5 Appendix D: Biofilm data (Vector) ........................................................ 182
7.6 Appendix E: Biofilm data (Aarhus) ........................................................ 183
7.7 Appendix F: Biofilm data (TOMAS) ....................................................... 184
7.8 Appendix G: Biofilm data (Leone) ......................................................... 185
Chapter 8 - References ........................................................................................ 187
8.1 List of references .................................................................................. 188

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List of abbreviations

Al Aluminium
ANOVA Analysis of variance of mean
AFM Atomic force microscopy
Australian Society of Orthodontists
ASOFRE
Foundation for Research and Education
CHX Chlorhexidine
F Fluoride
FCS Flow Cytometry Standard
OMSI Orthodontic mini screw implant
PMSF Phenylmethanesulfonylfluoride
PI Propidium iodide
SEM Scanning Electron Microscopy
TAD Temporary anchorage device
TO Thiazole orange
Ti–6Al–4V Titanium alloy (Titanium, Aluminium, and Vanadium)
V Vanadium

Page | 7 of 237
List of figures

Figure 1.1 : Orthodontic devices to assist in anchorage control. ................................. 23
Figure 1.2 : Implants in dentistry: ................................................................................ 24
Figure 1.3 : Onplant type TADs. ................................................................................... 35
Figure 1.4 : Proposed location of zygoma wires. ......................................................... 39
Figure 1.5 : Examples of miniplates, and their usage. .................................................. 39
Figure 1.6 : Implant supported palatal arch ................................................................ 41
Figure 1.7 : Orthogonal view of monocortical and bicortical OMSI ............................. 71
Figure 1.8 : Some of the various head designs available ............................................. 75
Figure 1.9 : Potential sites for placement of OMSI ...................................................... 88
Figure 1.10 : Scanning electron micrograph of a clinically failed OMSI (Ti6Al4V). ....... 97
Figure 1.11 : Diagrammatic representation of biofilm formation.. ............................ 100
Figure 3.1 : The INTEGRA Modular Atomic Force Microscopy Unit ........................... 112
Figure 3.2 : Schematic diagram of how an AFM works. ............................................. 113
Figure 3.3 : Experimental procedure to culture biofilms on the implant surfaces. .... 117
Figure 3.4 : 3D models generated from scanning of the Aarhus OMSI ...................... 121
Figure 4.1 : Examples of the OMSI used for the experiment ..................................... 124
Figure 4.2 : Example of SEM images at various magnifications. ................................ 127
Figure 4.3 : Example of SEM images at various magnifications. ................................ 128
Figure 4.4 : Example of SEM images at various magnifications. ................................ 129

Page | 8 of 237
Figure 4.5 : Example of visual and numerical output for typical AFM sample. ........... 130
Figure 4.6 : Representation of surface roughness as measured by AFM for Aarhus .. 131
Figure 4.7 : Representation of surface roughness as measured by AFM for Vector .. 132
Figure 4.8 : Representation of surface roughness as measured by AFM for Leone ... 133
Figure 4.9 : Representation of surface roughness as measured by AFM for TOMAS . 134
Figure 4.10 : Box plot showing the mean roughness of investigated implant groups. 137
Figure 4.11 : Graph showing scatter vs. thiazole orange stain (Sample B1) .............. 140
Figure 4.12 : Graph of number of cells vs. PI for typical sample (No Intervention) .... 141
Figure 4.13 : Graph showing number of cells vs. PI for typical sample (CHX). ........... 142
Figure 4.14 : Graph showing number of cells vs. PI for typical sample (Fluoride) ...... 143
Figure 4.15 : Box plot showing the mean bacteria grown on each implant group. .... 146
Figure 4.16 : Box plot of killing efficiency of CHX Vs. F on the surface of OMSI. ........ 149
Figure 4.17 : Box plot of killing efficiency of CHX vs. F on OMSI (Across all groups) .. 150

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