Evidence for clinical interventions 6 Butani et al. Pediatric Dentistry – 27:1, 2005
To answer these questions appropriately, the clinician needs
to support the treatment plan with sound scientific evidence
rather than using only personal clinical observations about
prognosis and treatment efficacy. Basing clinical decisions on
evidence from the literature is a more recent trend in dentistry,
and is known as “evidence-based practice.”1
hen seeking care, patients often inquire about
the treatment choices available to them, the
prognoses, and costs associated with treatments.
Evidence-based practice is based on the principles of
clinical epidemiology. These principles hold the evidence
from randomized controlled clinical trials to be the “gold
standard” for outcomes evaluations. Randomized clinical
trials (RCTs) are considered the most valid study design
for evaluating outcomes because they minimize bias and
confounding, and can most clearly establish efficacy.2
To provide answers to patients’ questions, the clinician
searches the scientific literature to find relevant studies that
Overview of the Evidence for Clinical Interventions in
Yogita Butani, BDS, MS Steven M. Levy, DDS, MPH Arthur J. Nowak, DDS, MA
Michael J. Kanellis, DDS, MS Keith Heller, DDS, DrPH Arthur J. Hartz, MD, PhD Deborah V. Dawson, PhD
Catherine A. Watkins, DDS, MS, PhD
Dr. Butani, at the time of this study, was a graduate student , Department of Preventive and Community Dentistry, College of Dentistry;
Dr. Levy is professor, Departments of Preventive and Community Dentistry and Epidemiology, Colleges of Dentistry and Public Health;
Dr. Nowak is professor emeritus, Departments of Pediatric Dentistry and Pediatrics, College of Dentistry; Dr. Kanellis is associate professor and
head, Department of Pediatric Dentistry, College of Dentistry; Dr. Heller, who passed away on April 26, 2004, was assistant professor, Depart-
ment of Preventive and Community Dentistry, College of Dentistry; Dr. Hartz is professor, Department of Family Medicine, College of Medi-
cine; Dr. Dawson is professor, Departments of Preventive and Community Dentistry and Biostatistics, Colleges of Dentistry and Public Health;
Dr. Watkins was assistant professor, Department of Preventive and Community Dentistry, College of Dentistry, University of Iowa, Iowa City,
Correspond with Dr. Levy at firstname.lastname@example.org
Purpose: The purpose of this report was to describe the quantity of published literature
and types of studies supporting the use of 4 pediatric dentistry procedures: (1) ferric sulfate
pulpotomy; (2) stainless steel crowns; (3) space maintainers; and (4) atraumatic restor-
ative technique (ART).
Methods: When available, titles and abstracts of reports written in English and pub-
lished over a 36-year period (1966-2002) concerning these procedures were retrieved
from MEDLINE. They were classified using a modified classification scheme that, in
addition to the study designs, also considered the 4 dimensions of measuring dental
Results: The quantity of available literature concerning each dental procedure varied con-
siderably. Even though many reports were published on treatments, only a small
proportion of the published literature for each procedure was found to evaluate outcomes,
regardless of outcome dimension. Besides outcomes evaluations, studies on techniques,
material properties, and review articles comprised a large proportion of the literature.
Clinical dimension of outcomes was most commonly studied. Case series and case re-
ports were the most frequently used study designs to report outcomes.
Conclusions: The outcomes-related literature to support some of the commonly per-
formed treatments is limited both in quantity and study types. More reports are needed
to develop the evidence base to support the commonly performed procedures in pediat-
ric dental practice. Additional analyses reporting of the literature are also needed to assess
internal and external validity of the studies. (Pediatr Dent. 2005;27:6-11)
KEYWORDS: EVIDENCE BASE, LITERATURE REVIEW, CLINICAL INTERVENTIONS,
Received March 22, 2004 Revision Accepted November 24, 2004
Scientific Articl e
Evidence for clinical interventionsPediatric Dentistry – 27:1, 2005Butani et al. 7
support his/her treatment plan. This retrieval of literature
and its assessment to answer questions (translating the evi-
dence into individual clinical practice or assessing the
external validity of the results) has been described as a 3-
1. assessment of evidence availability;
2. assessment of evidence quality;
3. synthesis of the evidence from multiple studies to draw
The study types that could potentially be used to draw
inferences should report outcomes, which are objective
measures of performance.4,5 Reports suggest that the pedi-
atric dental literature and dental literature as a whole have
very limited outcomes evaluations.4-6 To assess the quan-
tity and types of studies that form the evidence base for
clinical interventions, it is essential to differentiate between
the literature that reports outcomes from that which reports
other aspects of treatment procedures.
This study is part of a larger study whose purpose was
to evaluate the influence of study design on outcomes—in
other words, to compare the outcomes reported by ran-
domized controlled clinical trials to those from comparative
observational studies (OS) with concurrent controls. To
assess the influence of study design and methodology on
outcomes, the published literature was searched for treat-
ment comparisons that were evaluated using both RCT and
comparative OS study designs and assessed outcomes in a
common dimension. Thus, this report presents results on
the availability of literature and types of studies for 4 clinical
interventions in pediatric dental practice.
The published scientific literature on 4 clinical interven-
tions performed exclusively in children was selected for
review to assess its quantity and types of studies. The 4 clini-
cal interventions were: (1) ferric sulfate pulpotomy; (2)
stainless steel crowns; (3) space maintainers; and (4)
atraumatic restorative technique (ART).
These treatments were selected for 2 reasons:
1. These procedures generally are performed exclusively
2. They are either accepted as a “standard of care” or are
often compared to treatments accepted as “standard
of care” for restoring teeth and function.
The relevant reports were identified through
MEDLINE and classified using a modified classification
scheme to make an assessment of the quantity and types
of studies in the published literature. The literature search
and classification used is described in the following sections.
To identify the relevant reports published over a 36-year
period (1966-2002) indexed on MEDLINE, a combina-
tion of appropriate MeSH headings, keywords, and phrases
were used (summarized in Table 1). The search was lim-
ited to studies written in the English language, utilizing
human subjects less than 13 years of age, and published in
dental journals. Unpublished literature, theses, proceedings
from consensus conferences, and abstracts from scientific
meetings were excluded.
Classification of the reports retrieved was based on review of
the titles and abstracts of the identified studies. To classify the
types of studies that make up the body of literature, the hier-
archical classification suggested by the Canadian Task Force
on the Periodic Health Examination7 was used as a framework.
In addition, the following literature types were also
counted: (1) reviews; (2) systematic reviews and meta-
analyses; (3) letters; (4) comments and editorials; (5) in
vitro studies; (6) technique articles; (7) practice guidelines
and recommendations; and (8) surveys of knowledge, at-
titudes, and behaviors.
The studies that evaluated outcomes were also subclas-
sified in the 4 dimensions of oral health care outcomes: (1)
biological; (2) clinical; (3) psychosocial; and (4) economic.6
The following definitions were employed to classify the
1. Biological dimension: includes outcomes associated
with physiological and microbiological conditions and
processes. Physiological status outcomes include con-
siderations such as salivary or crevicular flow and
demineralization. Microbiological status outcomes
focus on presence or concentration of pathogens. Sen-
sory status outcomes deal with pain and parasthesia.
2. Clinical dime ns ion: includes survival status, characteris-
tics of restorations, and functional states. Survival status
addresses longevity and loss of teeth, tooth surfaces, res-
torations, and devitalization. Mechanical status addresses
characteristics of restorations. Diagnostic status outcomes
are presence of pathology, caries, and periodontal disease.
Functional status outcomes address patient-level behav-
iors dependent on speaking and chewing.
3. Psychosocial dimension: includes assessments of satis-
faction, perceptions, and preferences of oral health
status. The concepts included in this dimension range
from satisfaction with treatment to perception of and
satisfaction with esthetics and with oral health status
preferences for various health states or health events
and assessments of oral health-related quality of life.
4. Economic dimension: includes assessments of financial
and nonfinancial costs of treatment to the patient,
provider and insurer in terms of out-of-pocket costs,
and costs for treatment and retreatment. Also included
are forgone wages or other opportunity costs (eg,
transportation costs) that are considered indirect costs.
5. Randomized controlled trials: experimental studies
comparing groups that have been randomized to the
treatment they receive.
6. Nonrandomized controlled trials: experimental studies
comparing groups that have not been randomized to
the treatment they receive.
Evidence for clinical interventions8 Butani et al. Pediatric Dentistry – 27:1, 2005
7. Cohort studies: observational studies assembling a
group of people (a cohort), none of whom has expe-
rienced the outcome of interest, but all of whom could
experience it. Retrospective chart reviews were classi-
fied as cohort studies.
8. Case control studies: observational studies where the
cases and controls are compared after they have had
9. Cross sectional study: studies that report findings at one
point in time.
10. Case series: studies of larger groups of patients with a
particular condition with the absence of a compari-
11. Case reports: detailed presentations of a single case or
Reviews and expert opinions were classified separately
from systematic reviews and meta-analyses. Studies that used
the materials or techniques for alternate procedures or non-
traditional uses of the material were classified as “other uses”
and not classified using the classification scheme. Studies that
reported on practices and policies of use and did not report
outcomes were classified under surveys. Such studies usu-
ally report numbers of restorations placed but do not report
on outcomes. This category also included studies on knowl-
edge, attitudes and behaviors of providers, and attitudes of
patients toward treatments. Surveys of oral health-related
assessments of quality of life were included in the psychoso-
cial dimension and not classified under surveys. Letters and
comments include letters to the editor, responses to outcomes
or methodology reported in previously published studies, or
concerns about outcomes.
One author classified the studies using the title and ab-
stract. Each study was counted only once.
There was a wide range in the numbers of reports found
for the different topics. Overall, there were few random-
ized controlled trials. Reviews, expert opinions, and studies
on techniques were very common. Outcomes evaluations
for clinical interventions reviewed here were relatively lim-
ited, and the clinical dimensions of outcomes were the most
commonly studied. Economic, psychosocial, and biologi-
cal dimensions of outcomes were seldom studied. A large
proportion of the literature was found to be discussions of
techniques of use, reviews, and expert opinion. Specific
results on the types of studies
on each procedure are pre-
sented in the following
sections and in Tables 2 to 5.
Ferric sulfate pulpotomy
Even though numerous reports
exist regarding techniques and
outcomes for pulpotomy, only
6 were found on MEDLINE
that report on uses of ferric sul-
fate as a pulpotomy agent. This
was the smallest number of studies identified for any treat-
ment considered here. All 6 reports evaluated the clinical
dimension of outcomes. By study design, the 6 reports were:
(1) 2 RCTs; (2) 1 non-RCT; (3) 2 cohort studies; and (4) 1
review of literature.
Stainless steel crowns
A total of 122 articles were identified on stainless steel crown
restorations in children. Of the 122 articles, 45 evaluated
clinical outcomes, 4 evaluated biological outcomes, 2 evalu-
ated psychosocial outcomes, and 1 evaluated economic
outcomes. All 45 articles that evaluated clinical outcomes
employed observational study designs. Sixteen of the 45 re-
ports on clinical outcomes were cohort studies, 2 were
case-control studies, 1 was a cross-sectional study, 5 were case
series, and 21 were case reports. Biological outcomes were
studied by case control (2 studies) and case series (2 stud-
ies). Psychosocial outcomes were studied by case control (1
study) and case series (1 study). Economic outcomes were
studied by case control study design.
In addition to outcomes evaluations, 70 reports dis-
cussed other aspects of the treatment. Of the 70 reports,
12 were reviews or expert opinions, 1 was a systematic re-
view, 5 were in vitro studies, 13 were reports of surveys of
practices and use of stainless steel crowns, 21 were articles
on techniques of tooth preparation and crown cementa-
tion, 2 were practice guidelines, 7 were letters or editorials,
and 9 were studies that discussed uses of stainless steel
crowns other than restorations of primary molars.
Ninety-nine reports were retrieved on space maintainers,
26 of which evaluated clinical outcomes and 1 of which
evaluated economic outcomes. Reports on outcomes evalu-
ations were mainly case reports, case series and cohort
studies. In addition to the reports on outcomes, 42 stud-
ies addressed techniques of fabrication or considerations
and indications for space maintainers.
Thirty-seven ART reports were identified—22 of which
evaluated the clinical dimension of outcomes. Ten of these
studies used the cohort study design, 9 were case-control
studies, and 1 was a randomized controlled trial. One study
evaluated economic outcomes using a cohort study design.
Stainless steel crownsPreformed crowns, stainless steel crowns, ion-chrome crowns,
pre-formed crown, stainless steel crown
Ferric sulfate, ferric sulphate, pulpotomy, pulp therapy
Space maintainer(s), space management, space control,
deciduous tooth loss, premature loss
Ferric sulfate pulpotomy
technique (ART)Atraumatic restorative technique, ART, glass ionomer cement
Table 1. Keywords and MeSH Headings Used to Identify Studies
Evidence for clinical interventions Pediatric Dentistry – 27:1, 2005Butani et al. 9
Of the other 14, 7 were reviews and expert opinions, 3 were
reports on practices of use, and 2 were in vitro studies. Most
of the studies that reported ART outcomes were field trials.
Four clinical interventions were selected for review so the
available literature could be assessed in detail for the avail-
able types of evidence. This can provide a better
understanding of what types of studies are published in the
pediatric dental literature. This evaluation of the published
pediatric dental literature is unique in that it describes the
proportion of outcome-related literature from the overall
literature published concerning the 4 materials considered.
There was substantial variation in numbers of studies per
topic, ranging from 6 on ferric sulfate pulpotomy to 122 on
stainless steel crowns. Only a modest proportion of studies
on each topic evaluated outcomes. The clinical dimension
of outcomes was most commonly studied. The research de-
signs most often utilized to study the treatments were case
series and case reports. Also, most of the studies on outcomes
that were found were case series and case reports. The next
most numerous were reviews and expert opinions, which is
in line with a study by Nainar reporting that level III (case
series and case reports) is the most common category of study
designs used in the pediatric dental literature.4
Careful evaluations of the dental practice outcomes in
all domains—not only in the clinical domain, but also in-
cluding biological, psychosocial, and economic
aspects—are required to provide the information needed
to continue to improve the quality of care and demonstrate
the value of dental treatments to dentists, patients, and
payers.8 Providing the research to allow dentists to transi-
tion from an empiric-based to an evidence-based practice
is a challenging but worthwhile goal.
Several studies in the dental literature have reported on the
paucity of outcomes-related dental literature. A systematic
review by Patton et al9 was intended to compare the occur-
rence of complications for 7 dental procedures in HIV-positive
and healthy patients. The dental procedures of interest were:
(1) orthognathic surgery; (2) periodontal therapy; (3) dental
implants; (4) prophylaxis or scaling and root planning; (5)
endodontic therapy; and (6) extractions. The authors reported
that they did not find any published literature on complica-
tions for orthognathic surgery, periodontal therapy, dental
Letter, editorial, abstracts
In vitro studies
Table 3. Classification of Literature for Stainless Steel Crowns (N=122)
Letter, editorial, abstracts
In vitro studies
Table 2. Classification of Literature on Ferric Sulfate Pulpotomy (N=6)
Evidence for clinical interventions10 Butani et al. Pediatric Dentistry – 27:1, 2005
implants, prophylaxis, and scaling and root planning. Only 1
study was found on endodontic therapy, and there were 4 stud-
ies on extractions.9
Another systematic review of the published scientific
literature was undertaken. This was done to determine the
strength of the evidence for the efficacy of:
1. professional caries preventive methods applied to
2. professionally applied methods to arrest or reverse
noncavitated carious lesions.10
The results of this systematic review did not indicate that
the preventive and management methods reviewed are not
efficacious; rather, it demonstrated that not enough is
known to determine the efficacy of the methods.
Since the quality of evidence (outcomes assessment)
currently available to the clinician is not of the highest stan-
dards, enhancing its quality in future studies is an
important need. One possible step would be data collec-
tion in a systematic manner and analyses of outcomes.
Dental schools, hospitals, and private practice clinics main-
tain large patient data records. These collected data present
numerous opportunities for analyses. Ongoing and con-
tinuous data collection and analyses could help the
clinicians better understand the patterns of success of re-
storative materials and procedures.11
Another desirable step would be to improve the report-
ing of the scientific literature with the aim of enhancing
the quality of outcomes-related literature. Outcomes evalu-
ation in isolation has limited value, as the results may not
extrapolate to an individual clinician and his/her patients.
For the outcomes assessment studies to be more meaning-
ful to the clinician, it is important to study outcomes as
well as factors that influence them. Therefore, it is essen-
tial to integrate the studies’ results with the factors that
influence them and also assess the influences on outcomes.
The outcomes should be adjusted statistically for appro-
priate influencing factors to improve the study’s internal
and external validity. The findings of this and other stud-
ies that report on the study types and the quantity of the
pediatric dental literature indicate that enhancing both the
quality and quantity of the literature is imperative.2,6,11
Letter, editorial, abstracts
In vitro studies
Table 4. Classification of Literature on Space Maintainers (N=99)
Letter, editorial, abstracts
In vitro studies
Table 5. Classification of Literature on ART (N=37)
Evidence for clinical interventions Pediatric Dentistry – 27:1, 2005Butani et al. 11 Download full-text
For this study, the first step was to retrieve relevant stud-
ies using the electronic search engine MEDLINE, the
search engine for the National Library of Medicine. Elec-
tronic searching of journals is currently the most efficient
method of finding relevant studies, but the results of the
search can never be held as absolutely comprehensive. One
of this study’s limitations was that MeSH headings and
keywords were used to identify relevant studies on the
MEDLINE topics. The MeSH headings and keywords
were used in several different combinations to identify as
many studies as possible for each material. Indexing of stud-
ies under various keywords and MeSH headings, however,
is a subjective process. The librarians involved with index-
ing the studies do not follow a standard indexing method.
Only published studies were included in this classification,
subject to publication bias. Also, the selection was limited
to studies written in the English language in order to fa-
cilitate classification. Omission of useful studies written and
published in languages other than English likely occurred.
The identified titles and abstracts of studies were classi-
fied only once by 1 investigator. The issues of inter- and
intra-examiner reliability were, therefore, not addressed.
Thus, there is a chance that some studies could have been
This study reviewed the published literature on 4 pro-
cedures only. These findings may not be representative of
the entire pediatric dental restorative literature.
If the dental profession is to move toward evidence-based
dental practice, then there is an urgent need to collect and
report descriptive and analytical outcomes information that
will provide the evidence needed.12 A greater emphasis
should be placed on studying oral health outcomes in den-
tal education and research that go beyond the narrow range
of outcomes in clinical trials of dental materials.13
Based on the results of this report, several conclusions can
1. Overall, there is a large volume of literature on the pro-
cedures studied. Much of it, however, cannot be
termed as evidence-based or as having the potential
to be the basis for evidence-based practice, because
only a limited number of studies evaluated outcomes.
A large proportion of the literature on each procedure
studied evaluated properties of the materials, tech-
niques, surveys of current practices, practice
guidelines, and protocols.
2. Of the 4 dimensions of outcomes, the clinical dimen-
sion was most commonly studied.
3. There are very few randomized controlled trials for the
widely accepted clinical interventions reviewed for this
paper. Current clinical outcomes information is based
on observational study designs.
4. There is a need to enhance the quality of outcomes-
5. Outcomes need to be evaluated, along with assess-
ments of factors influencing outcomes.
6. Along with researchers, the responsibility to develop
the evidence base rests with the clinicians in private
practice by reporting outcomes from their clinical
This study was supported by a grant from the US Depart-
ment of Health and Human Services DHHS Agency for
Healthcare Research and Quality.
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