This document summarizes evidence from several studies on various aspects of evidence-based prosthodontics. It discusses types of studies used in evidence-based dentistry including systematic reviews, randomized controlled trials, cohort studies, and case reports. It then examines specific evidence related to prosthodontic treatment planning, factors influencing single-tooth implant decisions versus endodontic therapy, decision-making approaches in implant dentistry, outcomes of implants in augmented bone, and survival rates of different prosthesis types. The conclusion emphasizes that a multidisciplinary approach and shared decision-making is important in prosthodontic treatment planning based on available evidence and individual patient factors.
5. Types of Studies
• Systematic Reviews and
Meta-Analyses
• Randomized Controlled
Studies
• Cohort Studies
• Case Series and Case
Reports
• Case Control Studies
5
http://library.downstate.edu/EBM2/research.htm
6. Systematic reviews and meta-analyses
• A systematic review is a comprehensive survey of a topic in
which all of the primary studies of the highest level of
evidence have been systematically identified, appraised
and then summarized according to an explicit and
reproducible methodology.
6
7. • A meta-analysis is a survey in which the results of all of
the included studies are similar enough statistically that
the results are combined and analyzed as if they were one
study.
• In general a good systematic review or meta-analysis will
be a better guide to practice than an individual article
7
9. Randomized controlled studies
A randomized controlled study is one in which:
• There are two groups, one treatment group and one control
group. The treatment group receives the treatment under
investigation, and the control group receives either no treatment
or some standard default treatment.
• Patients are randomly assigned to all groups. 9
11. Cohort studies
• A cohort study is a study in which patients who
presently have a certain condition and/or receive a
particular treatment are followed over time and
compared with another group who are not affected by
the condition under investigation.
11
12. • Cohort studies are not as reliable as randomized
controlled studies
• The main problem with cohort studies, however, is that
they can end up taking a very long time, since the
researchers have to wait for the conditions of interest to
develop
12
14. Case series and case reports
14
Case series and case reports consist either of collections of
reports on the treatment of individual patients, or of
reports on a single patient.
http://library.downstate.edu/EBM2/research.htm
15. Case control studies
• Case control studies are studies in which patients who
already have a certain condition are compared with
people who do not
15
16. The main advantages of case control studies are:
• They can be done quickly.
• By asking patients about their past history, researchers
can quickly discover effects that otherwise would take
many years to show themselves.
• Researchers don't need special methods, control
groups, etc. They just take the people who show up at
their institution with a particular condition and ask
them a few questions. 16
17. Evidence-based dentistry :
Acronym is EBD; an approach to oral healthcare that
requires the judicious integration of systematic
assessments of clinically relevant scientific evidence,
relating to the patient’s oral and medical condition and
history, with the dentist’s clinical expertise and the
patient’s treatment needs and preferences;
17
GPT – 9, JPD April 2007; 117 (5)
18. The foundation for evidence based practice was laid by
David Sackett who has defined it as :
‘‘integrating individual clinical expertise with the
best available external clinical evidence from
systematic research”
18
Goldstein G. What is evidence based Dentistry. Dental Clinics of North America ; Volume
46 , number 1 , January 2002
19. • Lot of clinical questions are answered by combining our
intuition, training and clinical experience, which may
or may not be based on scientific evidence.
• This type of learning that relies heavily on clinical
experience and information learned in dental schools or
from colleagues, can lead to inappropriate treatment
outcomes
19
20. • Evidence-based dentistry attempts to answer clinical
questions based on a critical review of the most sound
scientific evidence available combined with one’s clinical
experience and scientific knowledge
20
21. History
• It is claimed that the origin of EBD dated back to the mid
19th century
• 1970- Introduced in Mac Master University
• 1980- Harvard University
• 1995 – Oxford University
• 2000- 1st Fed Dentaire Internationale workshop(Paris)
• 2000- 1st Center for EBD established in Davangere 21
22. Steps of evidence-based methods
1. Converting information needs into focused questions
2. Finding evidence to answer questions
3. Critically appraising the evidence for validity and
clinical usefulness
4. Applying results to clinical practice
5. Evaluating performance of evidence in clinical
applications
22
23. Use of Evidence Based Dentistry
• Use of evidence based dentistry in determining therapy
• Using evidence based dentistry to evaluate the need for a
diagnostic test
23
24. The use of evidence based dentistry in
determining therapy
• Was the assignment of patients to treatment
randomized?
• Were all patients who entered the trial properly
accounted for and attributed for at its conclusion?
• Were patients, their clinicians, and study personnel
blinded to treatment?
• Were the Groups Similar at the Start of the Trial?
24
25. • Aside from the experimental intervention, were the groups
treated equally?
• Were objective and unbiased outcome criteria used?
• Will the results help clinicians in caring for their patients?
25
26. Using evidence based dentistry to evaluate
the need for a diagnostic test
• Was there an independent, blind comparison with a
reference standard?
• Were the methods for performing the test described in
sufficient detail to permit replication?
• Were sensitivity, specificity, positive predictive value,
negative predictive value, and likelihood ratios
presented?
• Will the patient be better off as a result of the test?
26
27. What evidence based dentistry is not
• Evidence based dentistry is not a veil to mask the
same old, inadequate research.
• Evidence based dentistry does not take the clinical
decisions out of clinicians hands and put them into the
hands of the literature.
• In fact, the opposite is true. Evidence based dentistry
gives guidelines for the clinician and relies first on
clinical expertise.
• Evidence based dentistry does not mean that third
parties will control dental practices.
27
28. Who benefits from evidence based dentistry
• The ultimate beneficiaries of EBD are members of the
public, who will reap the rewards of better care.
• Dentists, who will also benefit from ebd
• Researchers, who will benefit by being called upon to do
the clinical testing necessary before new products are
placed on the market.
28
30. The need for evidence-based prosthodontics
• Enable the recognition of best available scientific evidence
in prosthodontics.
• Consolidate the scientific information overload in
prosthodontics and related literature.
• Scrutinize the scientific basis for existing prosthodontic
treatments.
• Improve current and future treatments.
• Encourage improvement in the quality of clinical research
as well as in reporting.
• Distinguish and advance the specialty of prosthodontics.
30
31. Traditional model of care in dentistry
31
The traditional model of care in dentistry involves use of
individual clinical expertise and patient treatment needs to
provide dental care.
32. 32
According to the American Dental Association (ADA),
EBD is defined as “an approach to oral healthcare that
requires the judicious integration of systematic assessments
of clinically relevant scientific evidence, relating to the
patient’s oral and medical condition and history, with the
dentist’s clinical expertise and the patient’s
treatment needs and preferences.”
35. Guidelines for reporting evidence
• CONSORT: Consolidated Standards of Reporting Trials
• TREND: Transparent Reporting of Evaluations with
Nonrandomized Design
• PRISMA: The objective of Preferred Reporting Items for
Systematic Reviews and Meta- Analyses
• MOOSE: Meta-analysis of Observational Studies in
Epidemiology
• SORT: Strength of Recommendation Taxonomy
• AMSTAR: Assessment of Multiple Systematic Reviews 35
37. The evidence for prosthodontic treatment
planning for older, partially dentate patients
Tooth Loss and Occlusal Instability:
• The consequences of posterior tooth loss show wide
individual variation and are at least partly predictable,
which suggests a management strategy of wait-and-see as
opposed to mandatory immediate replacement.
• The risks of bite collapse, and the consequent need for
interceptive prosthodontic therapy to replace molars in
SDA patients, are unsupported.
37
Med princ pract 2003;12(suppl 1):33–42
REVIEW 1
39. Tooth Loss, Occlusal Instability and Bruxism :
• Occlusion is not currently considered to be amongst the
essential aetiological factors for bruxism, and thus there is
no place for occlusal therapy, including prostheses, in its
prevention or treatment.
• In cases of advanced occlusal wear, treatment should be
limited to solving specific problems, although this may
very well indicate extensive reconstruction in some cases
39
REVIEW 1
40. Tooth loss and TMD
• Currently, the capacity of the masticatory system to
adapt to tooth loss is great, and does not warrant
replacement on preventive grounds alone.
• In general terms, the known potential for prostheses
to provoke sudden changes, it would be prudent to
exercise caution when considering prosthodontic therapy
in a patient, who, at the time of planned intervention, has
signs and symptoms of TMD. 40
REVIEW 1
41. • While Prosthodontic treatment might be indicated in
patients with loss of teeth together with occlusal
discrepancies, it cannot be promoted as a method of
preventing or treating TMD, and certainly not as an
alternative for failed conventional treatment of TMD.
41
REVIEW 1
42. Tooth Loss and Chewing Ability
• Objective tests show that chewing efficiency decreases in
relation to the number of remaining occluding teeth.
• Subjectively, there is no such correlation for reported
chewing ability, with chewing satisfaction generally
reported with 20 or more remaining teeth.
• Distal extension RPDs do not contribute to subjective
chewing ability.
42
REVIEW 1
43. Adaptation and Patient-Perceived Needs and
Outcomes
• Adaptation influences the degree of functional
impairment.
• Morphological deficits alone are therefore of limited
value in determining a patient’s treatment need.
• Patient demand for posterior tooth replacement is
relatively weak.
• Patients’ satisfaction with treatment depends on their
expectations being met.
43
REVIEW 1
44. Conclusion
• The evidence indicating that it is necessary to change the
way in which clinicians plan and deliver treatment to
reflect the new situation is compelling.
• Research has shown the relevance of the SDA concept for
managing the older adult with a reduced, compromised
dentition.
44
REVIEW 1
45. A review of factors influencing treatment planning
decisions of single-tooth implants versus preserving
naturalteethwith nonsurgicalendodontictherapy
• Owing to the high survival and success of oral implants,
they have become a popular treatment modality to
replace missing teeth
• Unfortunately however, their popularity may be related
to the misconception that periodontally or
endodontically compromised teeth should be removed
rather than maintained, and the missing tooth replaced
by an oral implant 45
JOE — Volume 34, Number 5, May 2008
REVIEW 2
46. • Dental implants provide a useful alternative in replacing
teeth that cannot be treated with a good prognosis.
• However, implants evoke surgical-induced
pain/inflammation, are about twice as expensive as
nonsurgical endodontic therapies, are associated with
greater post-treatment interventions, and provide no
better survival rates than the restored endodontically
treated tooth. 46
REVIEW 2
47. • On the basis of these considerations, the routine selection
of single-tooth implants cannot be recommended for the
treatment of compromised teeth that could otherwise be
saved by endodontic therapy.
• A compromised tooth should be managed with a
multidisciplinary approach, and dental implants should
be reserved only for the patient with truly end-stage
tooth failure.
47
REVIEW 2
48. • There is a great deal of heterogeneity in studies regarding
outcome measures, criteria for success, implant type, and
time of loading of implants
• Also major attrition bias, ie, loss of patients on recall
examinations makes the studies less reliablel
• Thus for clinical decision making or might overestimate
intervention effectiveness
48
REVIEW 2
49. • The published literature does not allow direct
comparisons of single-tooth implants and restored
root canal–treated teeth because of dissimilarities in
study design and content of data collected.
• It is recommended that future studies should attempt to
provide survival data that are more comparable to real-
life situations experienced in private practice settings.
49
REVIEW 2
50. Decision making in implant dentistry: an evidence-based
and decision-analysisapproach
• The evidence-based approach and decision analysis
constitute two major approaches in decision making in
implant dentistry.
• A number of systematic reviews have been published
regarding the success and survival rates of teeth
following periodontal and endodontic treatments and of
dental prostheses supported by teeth or implants
50
Periodontology 2000, Vol. 50, 2009, 154–172
REVIEW 3
51. Number of teeth needed for masticatory function:
• Occlusal support and stability was maintained with
three to four functional posterior units with a
symmetrical pattern of tooth loss or five to six units with
an asymmetrical pattern.
• When fewer than 20 teeth were present, masticatory
efficiency and ability were likely to be impaired.
• Furthermore, loss of anterior teeth markedly impaired
esthetics, and also the patients satisfaction and utility 51
REVIEW 3
52. Impact of implant-supported dental prostheses on oral
health related quality of life
• Conclusive evidence has indicated that patients with
implant-supported overdentures in the mandible report
improved satisfaction with chewing compared to patients
with conventional complete removable dental prostheses
52
REVIEW 3
53. Overall retention of natural teeth
• Factors that may explain the variance in the incidence of
tooth loss include education, occupation, personal
economic situation attitudes to dental care, lifestyle
factors such as smoking, and access to dental care
53
REVIEW 3
54. • It has been shown that teeth adjacent to posterior
bounded edentulous spaces have a greater estimate 10-
year survival rate when the space was restored with a
fixed dental prosthesis (92%) compared to when the
space remained untreated (81%) (Fig. 2).
• Teeth adjacent to spaces restored with a removable
partial denture had the poorest 10-year survival
54
REVIEW 3
55. Outcomes of oral implants placed in augmented bone
• The survival rates of implants in augmented bone were
found to be similar to those generally reported for
implants placed in nonaugmented sites
• The method of bone augmentation does not seem to affect
the outcomes of implant therapy because implant survival
rates were comparable following guided bone
regeneration and distraction osteogenesis 55
REVIEW 3
56. Outcomes of implant-supported fixed dental prosthesis
• The estimated annual failure rate for implant-
supported fixed dental prostheses was reported to range
from 0.99 to 1.43 per 100 implant-supported fixed
dental prostheses years, translating into a 5-year survival
rate of 95.2% and a 10-year survival rate of 86.7% (57).
• The survival rates have been found to be closely related
to the type of veneer material utilized.
56
REVIEW 3
57. • Five years following placement, metal-ceramic implant-
supported fixed dental prostheses showed a significantly
higher survival rate of 96.7%
• Metal-ceramic crowns showed a significantly higher 5-
year survival rate than all-ceramic crowns
57
REVIEW 3
58. • Outcomes of tooth-supported fixed dental prostheses
• Tooth-supported fixed dental prostheses on abutment
teeth with severely reduced periodontal tissue support
that received periodontal supportive therapy.
• The survival rates of these prostheses were found to be
96.4%
58
REVIEW 3
59. Concluding remarks
• Decision analysis holds great promise for aiding providers
and patients in shared decision making regarding the
retention or replacement of diseased teeth with implant-
supported dental prostheses.
• By quantifying outcomes for alternative treatments it may
help to identify the most appropriate care for individual
patients based on utility and costs and thereby mitigate
under-treatment and over-treatment.
59
REVIEW 3
60. All-ceramic or metal-ceramic tooth supported fixed dental
prostheses (FDPs)? A systematic review of the survival and
complicationrates.
Objective: to assess the 5-year survival of metal-
ceramic and all-ceramic tooth-supported fixed
dental prostheses (FDPS) and to describe the incidence
of biological, technical and esthetic complications.
60
REVIEW 4
Dental Materials, 2015. 31(6):624-639.
61. • In a systematic review clinical studies on newer
materials such as zirconia, lithium disilicate
reinforced glass ceramics and glass-infiltrated
alumina (in-ceram alumina) glass-infiltrated
alumina-zirconia (inceram-zirconia) were available,
but only few of them provided longer term data.
• Since that time, the evidence increased and clinical data
are available for a number of all-ceramic materials for
FDPS.
61
REVIEW 4
62. • The aim of the systematic review was therefore,
i) To update the previous systematic review on tooth-
supported FDPs with an additional literature search including
retrospective and prospective studies from 2007 to 2013
ii) To assess the 3year survival rate of tooth-
supported fixed dental prostheses (FDPs) and to describe
the rate of biological, technical and esthetic complications
iii) To compare the survival and complication rates of
metal-based FDPs and all ceramic FDPs
62
REVIEW 4
63. Materials and Method:
Medline (PubMed), Embase and Cochrane Central
Register of Controlled Trials (CENTRAL) searches (2006-
2013) were performed for clinical studies focusing on
toothsupported FDPs with a mean follow-up of at least 3
years.
This was complemented by an additional hand search and
the inclusion of 10 studies from a previous systematic
review 63
REVIEW 4
64. • Forty studies reporting on 1796 metal-ceramic and 1110 all-
ceramic FDPs fulfilled the inclusion criteria.
• Meta-analysis of the included studies indicated an
estimated 5-year survival rate :
Metal-ceramic FDPs - 94.4%
Reinforced glass ceramic FDPs - 89.1%
Glass-infiltrated alumina FDPs - 86.2%
Densely sintered zirconia FDPs was 90.4%
• The survival rate of all-ceramic FDPs was lower than for
metal-ceramic FDPs, the differences did not reach
statistical significance except for the glass-infiltrated
alumina FDPs
64
REVIEW 4
65. • Biological consieration
Secondary caries:
• 18 studies reported on the incidence of secondary caries
on the abutment level.
• The lowest annual complication rate 0.11% was reported
for reinforced glass ceramic FDPs and the highest
complication rate 0.65% was reported for densely
sintered zirconia FDPs.
Loss of vitality
• Loss of abutment vitality was reported in three studies
65
REVIEW 4
66. • Abutment tooth fracture
The incidence of F due to fracture of abutment teeth was
reported in 36 studies evaluating 2107 FDPs, out of which
22 were lost DPs lost.
66
REVIEW 4
67. Conclusion:
• The incidence of framework fractures was significantly
higher for reinforced glass ceramic FDPs and infiltrated
glass ceramic FDPs, and the incidence for ceramic
fractures and loss of retention was significantly higher for
densely sintered zirconia FDPs compared to metal-
ceramic FDPs.
67
REVIEW 4
68. Limitations of evidence-based prosthodontics
• Applicability of research to a specific patient population
• Publication biases
• Paucity of current data
• Cost
• Ethics
68
69. Conclusion
• Compared with the traditional model of care, EBD is
relatively new and, with progress in time, multiple clinical
questions for which currently there is weak evidence or
minimal/insufficient evidence should be resolved.
69
70. • Long-term survival and success of treatment, core
components of the specialty of prosthodontics, is an
important arena for channeling efforts and resources to
help further distinguish the specialty of prosthodontics
70
71. • It is thus, important to establish a consensus in
prosthodontics on defining the 3 core elements previously
described:
Defining Prosthodontic outcomes,
Duration needed for a meaningful understanding
of Prosthodontic outcomes, and
Sample size needed to make meaningful
conclusions.
71
72. References
• Ridwaan Omar, The Evidence For Prosthodontic
Treatment Planning For Older, Partially Dentate
Patients. Med Princ Pract 2003;12(suppl 1):33–42
• Gary R. Goldstein ,WHAT IS EVIDENCE BASED
DENTISTRY. Dental Clinics Of North Americ Volume 46
• Number 1 • January 2002
• Avinash S. Bidra, Evidence-based Prosthodontics
Fundamental Considerations, Limitations, And
Guidelines. Dent Clin N Am 58 (2014) 1–17 72
73. 73
• Thomas f. FLEMMIG & THOMAS BEIKLER, decision
making in implant dentistry: an evidence-based and
decision-analysis approach, periodontology 2000, vol. 50,
2009, 154–172
• Mian K. Iqbal, A review of factors influencing treatment
planning decisions of single-tooth implants versus
preserving natural teeth with nonsurgical endodontic
therapy, JOE — volume 34, number 5
It's rare that the results of the different studies precisely agree, and often the number of patients in a single study is not large enough to come up with a decisive conclusion
If the authors are interested in supporting a particular conclusion, they can include studies that support that conclusion and omit studies that do not
Studies that show some kind of positive effect tend to be published more
Do weak negative studies exist? This effect is known as Publication bias.
Assigning patients at random reduces the risk of bias and i.
Having a control group allows us to compare the treatment with alternative choices.
Randomized controlled trials are the standard method of answering questions about the effectiveness of different therapies.
With certain research questions, randomized controlled studies cannot be done for ethical reasons.
, cohort studies are generally preferred to case control studies , since they involve far fewer statistical problems and generally produce more reliable answers.
From:
, since a randomized controlled study to test the effect of smoking on health would be unethical
, a reasonable alternative would be a study that identifies two groups, a group of people who smoke and a group of people who do not, and follows them forward through time to see what health problems they develop.
. Case series and case reports, since they use no control group with which to compare outcomes, have no statistical validity .
For example: a study on which lung cancer patients are asked how much they smoked in the past and the answers are compared with a sample of the general population would be a case control study
This model of care has been used for centuries across the world and is primarily based on observations, beliefs,
and personal and expert opinions
Furthermore, it provides minimal confidence to
clinicians for making clinical decisions for new scenarios and new treatments
EBD process is not a rigid methodologic evaluation
of scientific evidence that dictates what practitioners should or should not do but als relies on the role of individual professional judgment and patient preference in this process
Surrogate outcomes include measures that are not of direct practical importance butare believed to reflect outcomes that are important as part of a disease/treatmentprocess.
True outcomes, however, reflect unequivocal evidence of tangible benefit
to patients.
Both types of outcomes are important in prosthodontics, because surrogate
outcomes are helpful for preliminary evidence and true outcomes are helpful for
definitive evidence
Evidence in medicine has been popularly categorized into 5 hierarchical levels and
widely represented as a pyramid with the “weakest/lowest level of evidence” at the
base and the “strongest or highest level evidence” at the apex.
This model may not be applicable Prostthodontics
the applicability of this paradigm to prosthodontics is questionable because few articles
in prosthodontics comprise RCTs and large cohort studies, implying that most
current clinical practices in prosthodontics are all based on
For example, results from a cohort or a case-control study
with a very large sample size and/or a long-term follow-up on all-ceramic crowns can
have a better impact on clinical decisions compared with results from an RCT with a
small sample and a short-term follow-up. In this scenario, in spite of RCT regarded as
the “strongest evidence,” it would fail to be used by clinicians for confident decision
making.“weak evidence.”
it is necessary for investigators to comply with certain guidelines for reporting scientific evidence
.
The common goal of all guidelines is to improve scientific reporting and ensure standardizationso that they allow an accurate assessment of the presented evidence.
loss of a single lower first molar, which was seen as concrete support for the concept of arch integrity
2. Teeth losing antagonists after 26 years of age had a lower risk of supraeruptio
3. Loss of all or most of the posterior teeth has traditionally been considered a significant risk for occlusal instability, giving rise to extensive and uncontrolled migration of teeth, and leading to posterior bite collapse, overclosure and further breakdown of the dentition [26].
In follow-up studies over 9 years [27, 28], researchers investigated the stability of the SDA, which consists of 20 teeth (fig. 3.
1. Loss of molar support was believed to be an aetiological factor in TMD, which led to the strategy of replacing molars in order to prevent as well as treat the condition
2. Although the evidence for such an
association is either weak or non-existent [34], there may be some circumstantial evidence that occlusal discrepancies play a predisposing role
comprehensive review
of patients’ satisfaction with their oral status and perceived
need for treatment showed that aesthetics play a
far stronger role in determining need than does chewing
function, and that 20 or more ‘well-distributed’ teeth provided
sufficient chewing ability; in people over 45 years of
age, such an arrangement satisfied their needs in relation
to both appearance and function [62]. This consensus
dovetails well with the SDA concept
Because the techniques for dental implants and root canal treatment have been refined and their long-term outcomes have become better understood, endodontists and implantologists must begin to treat different patient populations.
Most of the data related to single-tooth implants appear to be largely limited to industry-sponsored trials conducted in standardizeduniversity settings
Before summarizing the available evidence for
treatment outcomes a brief discussion regarding the impact
of the natural dentition or dental prostheses on
patients masticatory function and satisfaction is
warranted.
Taking this in considdration the concept of SDA cn be applies
Teeth with severe loss of periodontal tissue
support can be used successfully as abutments for
tooth-supported fixed dental prostheses, provided that
periodontal therapy is rendered (46).
With the increasing availability of electronic health records and progress in health informatics, robust decision-support tools may become available that can be integrated into the clinical workflow
There are some well-known limitations to EBD, and prosthodontics is no exception.