Table Of ContentEliciting Dentists’ and Patients’ Preferences for the
Treatment of Teeth with Apical Periodontitis
by
Amir Azarpazhooh
A thesis submitted in conformity with the requirements
for the degree of Doctor of Philosophy
Graduate Department of Dentistry
University of Toronto
© Copyright by Amir Azarpazhooh 2011
Eliciting Dentists’ and Patients’ Preferences for the
Treatment of Teeth with Apical Periodontitis
Amir Azarpazhooh
Doctor of Philosophy
Graduate Department of Dentistry
University of Toronto
2011
Abstract
Background: Teeth affected by apical periodontitis (AP) that could be retained by root canal
therapy (RCT) are increasingly being extracted and replaced with implant-supported crowns
(ISC).
Objectives: 1) To investigate preferences of dentists and patients towards retaining a tooth with
AP using RCT versus its extraction followed by, no replacement, replacement with an ISC, or
with a partial fixed or removable denture. 2) To investigate patients’ preferred role and dentists’
ethical responsibilities in decision-making.
Methods: A mail-out survey (sent to: dental specialists, n=195, response rate=39%; patients,
n=434, response rate=43%) and a web-based survey (general dentist sample, n=304, response
rate =15%) were used to collect data. Statistical bivariate and multivariate analyses were
undertaken with P set at < 0.05 with Bonferroni adjustment as necessary.
Results: RCT or ISC were the most selected treatment choices for dentists, while the preference
for RCT was reduced for teeth treated previously with RCT. Dentists’ preferences were
ii
associated with their specialty as well as clinical experience in endodontics and/or implant
dentistry. Patients’ stated general preference for saving teeth was associated with higher self-
rated oral health, frequent dental check-ups, and higher socio-demographic factors. Those with
higher education, regular dental visits and previous experience of RCT preferred to undergo RCT
for future treatment in comparison to those who never experienced RCT. Patients preferred a
collaborative role with their dentists in making treatment decisions and valued the retention of
natural teeth very highly. They also felt that communication with and trust in their dentist was
paramount.
Conclusion: Dentists should establish rapport with patients in a milieu that values and respects
the patients’ autonomy. By following the highest standards of evidence-based care, and
transferring unbiased information on treatment options and associated risks/benefits, it is highly
probable that dental care will be delivered in a more ethical manner than would otherwise be
possible.
ii i
Acknowledgments
This dissertation is the conclusion of a scientific research that has been carried out from 2007 to
2011 in the fulfillment of a Doctor of Philosophy degree in the Graduate Department of
Dentistry, University of Toronto, Canada. This thesis is the result of more than four years of
work whereby I have been accompanied and supported by many people. It is a pleasant aspect
that I have now the opportunity to express my gratitude to them.
This work would not have been possible without the precious help, advice, and support of my
research supervisor, the late Dr. David Locker; my acting primary supervisor, Dr. David Mock;
and my advisory committee members, Dr. Thuan Dao, Dr. Shimon Friedman, Dr. Wendy Ungar
and Dr. Murray Krahn.
I would like to extend my gratitude to Rafael Figueiredo, Ashkan Ebrahimpour, and Faiza
Chaudary for their tremendous research support.
I would like to dedicate this research to the memory of my late supervisor, Dr. David Locker. I
am sincerely thankful for his invaluable and exemplary academic guidance and support from the
commencement of my education at the University of Toronto (my MSc in Dental Public Health,
2004-2007), well into my PhD program and until his very last days. David’s inspiring attitude
always motivated me to achieve my goals. I will always remember him as a sympathetic person
who had a deep impression on me. I learned a lot from him through his unique style of respectful
and accountable mentorship. His trust and scientific excitement inspired me in the most
important moments of making right decisions. May he rest in peace.
iv
I am also grateful to Dr. David Mock, the Dean of the Faculty of Dentistry and my acting
primary supervisor; Dr. Morris Manolson, the Associate Dean of Graduate/Post-Graduate
studies; Dr. Howard Tenenbaum, the Graduate Coordinator; and Dr. Patricia Main, the head, and
Dr. Carlos Quiñonez, the director of the Discipline of Dental Public Health for their immediate
support upon David Locker’s death. In particular, my debt to Dr. Tenenbaum for his kindness,
wisdom, and continued encouragement is beyond words.
I would also like to gratefully acknowledge the support of some very special individuals. They
helped me immensely by giving me encouragement and friendship: Martha Clark, Rafael
Figueiredo, David Chvartszaid, Carlos Quiñonez, Dick Ito, Lusine Abrahamyan, Ashkan
Ebrahimpour, Ali Sakhdari, Parnian Ahmadi, and Farhad Akhavein.
This research was financially supported by the Dental Research Institute, Faculty of Dentistry,
University of Toronto, the Canadian Academy of Endodontics, and the International Federation
of Endodontic Associations. I have been fortunate to receive financial support for my
PhD/Specialty education from the Harron Scholarship, Faculty of Dentistry, University of
Toronto, the University of Toronto Open Fellowship, and the American Association of
Endodontists Foundation’s Educator Fellowship.
Lastly and most importantly, I would like to thank my wonderful parents, my dear sisters, my
brother for their loving support and encouragement throughout my years of education, and my
closest friend, my soul mate and my dear wife, Bita, for her love, patience, and sacrifices. To
them, I owe the greatest debt of gratitude.
Dr. Amir Azarpazhooh- Toronto, Canada, March 2011
v
Table of Contents
ACKNOWLEDGMENTS
.......................................................................................................................................
IV
TABLE
OF
CONTENTS
........................................................................................................................................
VI
LIST
OF
TABLES
.................................................................................................................................................
XII
LIST
OF
PLATES
................................................................................................................................................
XIV
LIST
OF
FIGURES
................................................................................................................................................
XV
LIST
OF
APPENDICES
....................................................................................................................................
XVII
CHAPTER
1
TREATMENT
MODALITIES
FOR
TEETH
WITH
APICAL
PERIODONTITIS
...................
1
1
BACKGROUND
................................................................................................................................................
1
1.1
APICAL
PERIODONTITIS
AND
ITS
TREATMENT
MODALITIES
..................................................................................
1
1.1.1
Endodontic
treatment
.........................................................................................................................................
1
1.1.2
Extraction
with
no
replacement
.....................................................................................................................
3
1.1.3
Extraction
and
replacement
with
removable
partial
denture
..........................................................
3
1.1.4
Extraction
and
replacement
with
fixed
partial
denture
.......................................................................
4
1.1.5
Extraction
and
replacement
with
implant
supported
crown
.............................................................
4
1.1.6
Implant-‐supported
crown
versus
root
canal
treatment
.......................................................................
5
1.1.6.1
Treatment
outcome
........................................................................................................................................................................
8
1.1.6.2
Function
and
psychosocial
outcomes
...................................................................................................................................
12
1.1.6.3
Length
of
time
required
to
restore
to
normal
function
.................................................................................................
13
1.1.6.4
Cost
of
treatment
...........................................................................................................................................................................
14
1.2
RECOMMENDED
APPROACH
FOR
DECISION-‐MAKING
...........................................................................................
15
1.3
OBJECTIVE
OF
THESIS
.................................................................................................................................................
17
1.4
THESIS
RESEARCH
QUESTIONS
................................................................................................................................
17
v i
1.4.1
Chapter
2-‐
Eliciting
Dentists’
Preferences
for
the
Treatment
of
Teeth
with
Apical
Periodontitis
.........................................................................................................................................................................
17
1.4.2
Chapter
3-‐
Eliciting
Patients’
Preferences
for
the
Treatment
of
Teeth
with
Apical
Periodontitis
.........................................................................................................................................................................
18
1.4.3
Chapter
4
-‐
Clinical
Decision-‐making;
The
Patient’s
Role
.................................................................
18
1.4.4
Chapter
5-‐
General
discussion:
Patients’
versus
dentists’
perspective
of
the
important
factors
related
to
decision-‐making-‐
Implication
for
practice
........................................................................
19
1.5
SUPPLEMENTS
TO
CHAPTER
1,
TABLES
AND
FIGURES
........................................................................................
20
CHAPTER
2
ELICITING
DENTISTS’
PREFERENCES
FOR
THE
TREATMENT
OF
TEETH
WITH
APICAL
PERIODONTITIS
..................................................................................................................................
22
2
ABSTRACT
.....................................................................................................................................................
22
2.1
METHODOLOGY
...........................................................................................................................................................
24
2.1.1
Objectives
...............................................................................................................................................................
24
2.1.2
Design
......................................................................................................................................................................
24
2.1.3
Sampling
frame
...................................................................................................................................................
25
2.1.4
Sample
size
calculation
....................................................................................................................................
25
2.1.5
Survey
instrument
..............................................................................................................................................
28
2.1.5.1
Domain
1
–
General
questions
.................................................................................................................................................
28
2.1.5.2
Domain
2
–
Preference
ranking
for
treatment
options
.................................................................................................
29
2.1.5.3
Domain
3,
treatment
attribute
questions
............................................................................................................................
31
2.1.6
Survey
implementation
....................................................................................................................................
31
2.1.7
Data
Analysis
........................................................................................................................................................
32
2.2
RESULTS
.......................................................................................................................................................................
33
2.2.1
Response
rates
.....................................................................................................................................................
33
2.2.1.1
Mail-‐out
survey
for
the
specialists:
........................................................................................................................................
33
vi i
2.2.1.2
Web-‐based
survey
for
general
Dentists:
..............................................................................................................................
34
2.2.2
Descriptive
results
..............................................................................................................................................
34
2.2.3
Preference
ranking
based
on
education
...................................................................................................
35
2.2.3.1
Between-‐group
comparison
.....................................................................................................................................................
35
2.2.3.1.1
Scenario
1-‐Anterior
tooth
with
no
history
of
RCT
................................................................................................
36
2.2.3.1.2
Scenario
2:
Posterior
tooth
with
no
history
of
RCT
..............................................................................................
37
2.2.3.1.3
Scenario
3:
Anterior
tooth
with
previous
history
of
RCT
..................................................................................
39
2.2.3.1.4
Scenario
4:
Posterior
tooth
with
a
previous
history
of
RCT
.............................................................................
40
2.2.3.2
Within-‐group
comparison
.........................................................................................................................................................
41
2.2.4
Preference
ranking
based
on
performed
services
................................................................................
44
2.2.4.1
Between-‐group
comparisons
...................................................................................................................................................
45
2.2.4.1.1
Scenario
1
and
2:
Anterior
versus
posterior
tooth
with
no
history
of
RCT
..............................................
45
2.2.4.1.2
Scenarios
3-‐4:
Anterior
versus
posterior
tooth
with
previous
history
of
RCT
........................................
46
2.2.4.2
Within-‐group
comparison
.........................................................................................................................................................
48
2.3
DISCUSSION
..................................................................................................................................................................
48
2.3.1
Variability
in
decision-‐making
......................................................................................................................
56
2.4
CONCLUSION
................................................................................................................................................................
68
2.5
SUPPLEMENTS
TO
CHAPTER
2,
TABLES
AND
FIGURES
........................................................................................
70
CHAPTER
3
ELICITING
PATIENTS’
PREFERENCES
FOR
THE
TREATMENT
OF
TEETH
WITH
APICAL
PERIODONTITIS
..................................................................................................................................
94
3
ABSTRACT
.....................................................................................................................................................
94
3.1
INTRODUCTION
TO
THE
CHAPTER
...........................................................................................................................
96
3.2
METHODOLOGY
...........................................................................................................................................................
96
3.2.1
Objectives
...............................................................................................................................................................
96
3.2.2
Design
......................................................................................................................................................................
97
3.2.3
Sampling
frame
...................................................................................................................................................
97
3.2.4
Sample
size
calculation
....................................................................................................................................
98
vi ii
3.2.5
Survey
instrument
............................................................................................................................................
100
3.2.5.1
Domain
1,
treatment
preference
questions
....................................................................................................................
101
3.2.5.2
Domain
2,
preference
predictor
questions
......................................................................................................................
103
3.2.5.3
Domain
3,
treatment
attribute
questions
.........................................................................................................................
104
3.2.5.4
Domain
4,
the
oral
health
related
quality
of
life
(OHRQL)
questions
.................................................................
104
3.2.5.5
Domain
5:
Preferred
role
in
clinical
decision-‐making
................................................................................................
105
3.2.6
Survey
implementation
..................................................................................................................................
105
3.2.7
Data
Analysis
......................................................................................................................................................
106
3.3
RESULTS
.....................................................................................................................................................................
108
3.3.1
Response
rates
...................................................................................................................................................
108
3.3.2
Descriptive
results
............................................................................................................................................
108
3.3.2.1
Sociodemographic/predisposing
factors
.........................................................................................................................
109
3.3.2.2
Dental
visits
enabling
factors
................................................................................................................................................
109
3.3.2.3
Need
factors
..................................................................................................................................................................................
110
3.3.2.4
Oral
health
related
quality
of
life
.........................................................................................................................................
110
3.3.3
Preference
for
saving
tooth
versus
extraction
.....................................................................................
110
3.3.4
Preference
for
saving
tooth
using
RCT
versus
extraction
...............................................................
112
3.3.5
Preference
for
type
of
replacement
of
an
aching
tooth
...................................................................
116
3.4
DISCUSSION
................................................................................................................................................................
117
3.5
CONCLUSION
..............................................................................................................................................................
126
3.6
SUPPLEMENTS
TO
CHAPTER
3,
TABLES
AND
FIGURES
......................................................................................
127
CHAPTER
4
CLINICAL
DECISION-‐MAKING:
THE
PATIENT’S
ROLE
..................................................
148
4
ABSTRACT
..................................................................................................................................................
148
4.1
INTRODUCTION
TO
THE
CHAPTER
.........................................................................................................................
150
4.2
THE
CHANGING
ROLE
OF
THE
PATIENT
IN
CLINICAL
DECISION-‐MAKING
.....................................................
152
4.3
METHODOLOGY
.........................................................................................................................................................
153
ix
4.4
RESULTS
.....................................................................................................................................................................
155
4.5
DISCUSSION
................................................................................................................................................................
158
4.5.1
What
factors
are
associated
with
patient
participation
preferences?
......................................
161
4.5.2
Patient-‐Physician
interaction
.....................................................................................................................
163
4.6
CONCLUSION
..............................................................................................................................................................
166
4.7
ACKNOWLEDGEMENT
FOR
THIS
CHAPTER
...........................................................................................................
166
4.8
SUPPLEMENTS
TO
CHAPTER
4,
TABLES
AND
FIGURES
......................................................................................
167
CHAPTER
5
–
GENERAL
DISCUSSION
PATIENTS’
VERSUS
DENTISTS’
PERSPECTIVE
OF
THE
IMPORTANT
FACTORS
RELATED
TO
DECISION-‐MAKING:
IMPLICATION
FOR
PRACTICE
......
177
5
SUMMARY
OF
THE
PREVIOUS
CHAPTERS
AND
IMPLICATIONS
FOR
PRACTICE
.................
177
5.1
PRELIMINARY
STUDY
...............................................................................................................................................
181
5.1.1
Dentists’
perspective
........................................................................................................................................
183
5.1.2
Patients’
perspective:
......................................................................................................................................
187
5.1.3
Dentists’
versus
patients’
perspectives
....................................................................................................
190
5.1.4
Role
of
ethics
in
clinical
decision-‐making
..............................................................................................
193
5.1.5
Respect
for
patient
autonomy
.....................................................................................................................
195
5.1.6
Integrity
................................................................................................................................................................
197
5.1.7
Fairness
.................................................................................................................................................................
198
5.1.8
Beneficence
..........................................................................................................................................................
198
5.1.9
Compassion
..........................................................................................................................................................
199
5.2
GENERAL
LIMITATIONS
...........................................................................................................................................
200
5.3
CONCLUSION
..............................................................................................................................................................
203
5.4
IMPLICATIONS
FOR
FUTURE
RESEARCH
AND
KNOWLEDGE
TRANSFER
...........................................................
205
5.5
FINAL
COMMENTS
AND
CONCLUSIONS
.................................................................................................................
212
5.6
SUPPLEMENTS
TO
CHAPTER
5,
TABLES
AND
FIGURES
......................................................................................
213
x
Description:Objectives: 1) To investigate preferences of dentists and patients towards dentistry. Patients' stated general preference for saving teeth was
