bmj opendenture-bearing areas, thus avoiding the possibility of further resorption, associated with...
TRANSCRIPT
For peer review only
Impact of fixed implant-supported prostheses in edentulous
patients: protocol for a systematic review
Journal: BMJ Open
Manuscript ID: bmjopen-2015-009288
Article Type: Protocol
Date Submitted by the Author: 01-Jul-2015
Complete List of Authors: López, Carolina; Pontificia Universidad Catolica de Chile, Faculty of Medicine Saka, Constanza; Pontificia Universidad Católica de Chile, Faculty of Medicine Rada, Gabriel; Pontificia Universidad Católica de Chile, Evidence-based Health Care Program, Faculty of Medicine Valenzuela, Daniela; Universidad de Concepción, Centro de Rehabilitación Oral Avanzada e Impalantologia (CRAI)
<b>Primary Subject Heading</b>:
Dentistry and oral medicine
Secondary Subject Heading: Rehabilitation medicine, Evidence based practice, Geriatric medicine, Patient-centred medicine
Keywords: ORAL MEDICINE, THERAPEUTICS, GERIATRIC MEDICINE, REHABILITATION MEDICINE
For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml
BMJ Open on M
arch 18, 2020 by guest. Protected by copyright.
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j.com/
BM
J Open: first published as 10.1136/bm
jopen-2015-009288 on 23 February 2016. D
ownloaded from
For peer review only
Impact of fixed implant-supported prostheses in edentulous
patients: protocol for a systematic review
López S., Carolina1,
Saka, H., Constanza1
Rada, Gabriel1,2,3
Valenzuela, D., Daniela4
1
Faculty of Medicine, Pontificia Universidad Católica de Chile.
2 Evidence-based Health Care Program, Faculty of Medicine, Pontificia Universidad Católica de
Chile
3 Epistemonikos foundation
4 Centro de Rehabilitación Oral Avanzada e Impalantologia (CRAI), Universidad de Concepción
Lira 63, Santiago-Chile
Emails:
Carolina López: [email protected]
Constanza Saka: [email protected]
Gabriel Rada: [email protected]
Daniela Valenzuela: [email protected]
Corresponding author: Gabriel Rada
ABSTRACT
Introduction
Edentulism is a debilitating and irreversible condition described as the “final marker of disease
burden for oral health”. Therapy with dental implants is being used on a large scale to replace
missing teeth and to rehabilitate edentulous patients with overdentures and implant-supported
fixed dentures as a method for solving the problem of instability and lack of retention associated
with conventional removable prosthesis. Fixed implant-supported prosthesis are an alternative for
implant rehabilitation treatment that allow patient to have a new fixed teeth. They can be
indicated in partial or total edentulous and they can replace single teeth, or teeth and supporting
tissues (hybrid prosthesis). They overcome the limitations of conventional dentures, increasing
stability and retention, providing functional and psychological advantages for the patients.
Methods and analysis
We will electronically search for randomised controlled trials evaluating the effects of fixed
implant-supported prostheses in edentulous patients in the following databases:
Pubmed/MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials.
We will also try to obtain literature screening references of included studies, searching for trial
protocols in the WHO International Clinical Trials Registry Platform, reviewing International Team
for Implantology conference proceedings and searching for non-published studies through Open
Gray.
Page 1 of 9
For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml
BMJ Open
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960
on March 18, 2020 by guest. P
rotected by copyright.http://bm
jopen.bmj.com
/B
MJ O
pen: first published as 10.1136/bmjopen-2015-009288 on 23 F
ebruary 2016. Dow
nloaded from
For peer review only
Two researchers will independently undertake selection of studies, data extraction and
assessment of the quality of included studies.
Data synthesis and subgroup analyses will be performed using special Review Manager software.
Data will be combined in a meta-analysis using a random effects model. Results will be presented
as risk ratios for dichotomous data and as mean difference or standardized mean difference for
continuous data.
Ethics and dissemination
No ethics approval is considered necessary. Results of this study will be disseminated via peer-
reviewed publications and social networks.
Registration number PROSPERO: CRD42015022086
Strengths and limitations of this study
This will be the first systematic review to assess the impact of implant-supported prostheses in
edentulous patients on their oral health, quality of life and satisfaction. It aims to provide a high-
quality synthesis of current evidence for patients and clinicians about this question. The main
limitation is the heterogeneity of studies available on the subject and the subsequent possibility to
group them to analyze the evidence on each outcome of interest that we have defined.
Keywords: Dental Prosthesis, Implant-Supported, Denture, Complete, quality of life, patients’ satisfaction
INTRODUCTION
Description of the condition
Edentulism is a debilitating and irreversible condition described as the “final marker of
disease burden for oral health”. Although the prevalence of complete tooth loss has declined over
the last decade, it remains a major disease worldwide, especially among older adults (Emami
2013). Many factors influence the prevalence of edentulism between different countries and
regions, such as education, economic status, access and opportunity to oral health care, lifestyle
and attitudes to dental care. Edentulism can lead directly to impairment, functional limitation,
physical, psychological and social disability (Locker 1988), affecting general and oral health of
individuals and, therefore, their quality of life.
Complete denture therapy has become the conventional and most prescribed treatment
option for edentulous patients, providing improved esthetics and function (Caetano 2013).
However, bone resorption of the alveolar ridge, as a consequence of edentulism, brings lack of
denture stability and retention, especially for the lower prosthesis, reducing patient’s comfort,
chewing, phonetics and esthetics. Patients wearing conventional removable prosthesis often
complain about the instability of their dentures. This leads to a feeling of insecurity, inefficient
mastication and overall dissatisfaction with their prosthesis (Prithviraj 2014).
Therapy with dental implants is being used on a large scale to replace missing teeth and to
rehabilitate edentulous patients with overdentures and implant-supported fixed dentures
(Caetano 2013). Placement of endosseous dental implants to retain and support overdentures or
fixed complete dentures have been developed as a method for solving the problem of instability
and lack of retention associated with conventional removable prosthesis (Prithviraj 2014).
Page 2 of 9
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BMJ Open
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on March 18, 2020 by guest. P
rotected by copyright.http://bm
jopen.bmj.com
/B
MJ O
pen: first published as 10.1136/bmjopen-2015-009288 on 23 F
ebruary 2016. Dow
nloaded from
For peer review only
Improvement of retention and stability of the prosthetic rehabilitation through implant-supported
prosthesis leads to enhance speaking, swallowing and mastication ability and, therefore, improves
patients comfort and satisfaction.
Description of the intervention
Dental implants represent a proven treatment modality for restoration of edentulous jaws
(Papaspyridakos, 2014). Several factors play role on the decision between fixed and removable
implant dentures such as inter-foraminal space, inter-jaw relationship, oral hygiene, costs and
patient preferences (Barao 2013).
Fixed implant-supported prosthesis are an alternative for implant rehabilitation treatment
that allow patient to have a new fixed teeth. They can be indicated in partial or total edentulous
and they can replace single teeth, or teeth and supporting tissues (hybrid prosthesis). Selection of
one type or another depends on the patient bone volume and soft tissue conditions (Bedrossian
2008) in addition to economic factors and treatment cost. Fixed full-arch implant supported
prosthesis may be either screw or cement retained and are indicated in the presence of enough
bone and inter-arch space (Barao 2013). Clinical factors that may discard a fixed restoration are
mostly related to bone or soft tissues deficiencies. For this instance, rehabilitation can be done by
hybrid prosthesis.
Hybrid prosthesis are fixed rehabilitation composed of a metal-based framework covered
with complete denture components (resin and denture teeth), which is screwed onto the implants
or the abutments. This treatment modality allows patients to have a completely fixed prosthesis,
which can only be removed by a dental professional (Preciado 2013, Kwon 2014).
How the intervention might work
Fixed implant restorations are totally implant supported, with no transference of load to
denture-bearing areas, thus avoiding the possibility of further resorption, associated with tissue-
borne prosthesis (Bedrossian 2008). They also overcome the limitations of conventional dentures,
increasing stability and retention of the prosthetic rehabilitation and thus, improving speaking,
swallowing and chewing efficiency. This brings functional and psychological advantages for the
patients, enhancing their comfort and self-confidence.
Why it is important to do this review
Previous systematic reviews have addressed the impact of fixed prostheses in partial or
total edentulous persons in terms of survival and success (Kwon, 2014; Papaspyridakos, 2014;
Pjetursson, 2012¸ Lambert 2009), and biological and technical complications (Papaspyridakos,
2012; Pjetursson, 2012; Bozini 2011). However, none of these reviews have assessed the
subjective effects of fixed implant-supported prosthesis in edentulous patients. So, we not only
aim to update existing reviews, but also to supplement existing evidence by incorporating other
impact indicators such as satisfaction and quality of life.
Objectives
The aim of this systematic review is to evaluate the effects of fixed implant-supported
prostheses in edentulous patients and to assess their impact on oral health related quality of life
and satisfaction.
Page 3 of 9
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BMJ Open
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on March 18, 2020 by guest. P
rotected by copyright.http://bm
jopen.bmj.com
/B
MJ O
pen: first published as 10.1136/bmjopen-2015-009288 on 23 F
ebruary 2016. Dow
nloaded from
For peer review only
METHODS
Criteria for considering studies for this review
Types of studies
Type of studies
We will include randomised controlled trials.
Types of participants
We will include studies examining healthy edentulous patients or with stabilized conditions.
Type of interventions
The interventions of interest are full-arched fixed prosthesis and hybrid prosthesis. We will not
restrict by type and number of implants or attachment system.
Comparisons of interest are conventional prosthesis and implant-supported or implant-retained
overdentures.
Types of outcomes
• Primary outcomes:
- Patient satisfaction
- Quality of life
• Secondary outcomes:
- Clinician’s appraisals for treatment success
- Cost
- Technical complications
Search methods for identification of studies
Electronic searches
We will search MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials with no
language or publication restrictions:
The following strategy will be used to search MEDLINE (PubMed):
#1 "Dental Prosthesis, Implant-Supported"[Mesh]
#2 (Dental OR denture*) AND Prosthes* AND ((Implant NEAR Supported) OR Implant-
Supported)
#3 (Dental OR denture*) AND Prosthes* AND ((Implant NEAR fixed) OR Implant-fixed)
#4 (Dental OR denture*) AND Prosthes* AND ((full-arch NEAR fixed) OR full-arch)
#5 (Dental OR denture*) AND Prosthes* AND (hybrid)
#6 #1 OR #2 OR #3 OR #4 OR #5
#7 "Mouth, Edentulous"[Mesh]
#8 "Jaw, Edentulous"[Mesh]
#9 toothless [tiab]
#10 edentul*[tiab]
#11 #7 OR #8 OR #9 #10
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#12 randomized controlled trial [pt]
#13 controlled clinical trial [pt]
#14 randomized [tiab]
#15 placebo [tiab]
#16 randomly [tiab]
#17 trial [tiab]
#18 groups [tiab]
#19 #12 OR #13 OR #14 OR #15 OR #16 OR #17 OR #18
#20 animals [mh] NOT humans [mh]
#21 #19 NOT #20
#22 #6 AND #11 AND #21
The MEDLINE strategy will be adapted to the syntax and subject headings of the other
databases.
The electronic search will be supplemented by:
- Reviewing for additional relevant studies in references of included studies.
- Searching for trial protocols through the WHO International Clinical Trials Registry
Platform.
- Searching in International Team for Implantology conference proceedings
- Searching for unpublished studies through Open Gray.
Data collection and analyses
Deduplicated results of literature will be uploaded to Covidence software
(www.covidence.org).
Selection of studies
Two authors will independently screen the titles and abstracts yielded by the search
against the inclusion criteria. We will obtain full reports for all titles that appear to meet the
inclusion criteria or where there is any uncertainty. We will seek additional information from study
authors where necessary to resolve questions about eligibility. We will resolve disagreement
through discussion. We will record the reasons for excluding trials.
Extraction and management of data
Using standardized forms two reviewers will extract data independently from each
included study. To ensure consistency, we will conduct calibration exercises before starting the
review. Data abstracted will include demographic information, methodology, population, and
intervention, comparison and outcome details.
We will resolve disagreements by discussion, and one arbitrator will adjudicate unresolved
disagreements.
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on March 18, 2020 by guest. P
rotected by copyright.http://bm
jopen.bmj.com
/B
MJ O
pen: first published as 10.1136/bmjopen-2015-009288 on 23 F
ebruary 2016. Dow
nloaded from
For peer review only
Risk of bias in individual studies
Two reviewers will independently assess risk of bias using the Cochrane Collaboration tool
for assessing risk of bias (Higgins 2011) which considers random sequence generation, allocation
concealment, blinding of participants, personnel and outcomes, incomplete outcome data,
selective outcome reporting, and other sources of bias. A judgment will be made from the
extracted information, rated as ‘high risk’ or ‘low risk’.
If there is insufficient detail reported in the study we will judge the risk of bias as ‘unclear’
and the original study investigators will be contacted for more information. Disagreements will be
resolved first by discussion and then by consulting a third author for arbitration. We will compute
graphic representations of potential bias within and across studies using RevMan 5.1 (Review
Manager 5.1).
Measures of treatments effects
For dichotomous outcomes we will express the estimate of treatment effect of an
intervention as risk ratios (RR) (improved patient satisfaction/not) together with 95% confidence
intervals (CIs). For continuous outcomes we will use mean difference and standard deviation to
summarize the data and 95% CIs. Where continuous outcomes are measured using different
scales, the treatment effect will be expressed as a standardized mean difference (SMD) with 95%
CI.
Dealing with missing data
Where possible, we will attempt to contact the original authors of the study to obtain any
missing data. If important numerical missing data cannot be obtained, an imputation method will
be used.
Assessment of heterogeneity
We will assess the variations in treatment effect from the different trials by means of a
formal statistical test (Q statistic) and the I2
statistic. We will consider heterogeneity statistically
significant if the P value is < 0.1. A rough guide to the interpretation of the I2 statistic given in the
Cochrane Handbook is: 0 to 40% might not be important, 30 to 60% may represent moderate
heterogeneity, 50 to 90% may represent substantial heterogeneity, 75 to 100% considerable
heterogeneity.
Data synthesis
We will only conduct a meta-analysis if there are studies sufficiently homogeneous in
terms of design, population, interventions and comparators reporting the same outcome
measures.
The results for clinically homogeneous studies will be meta-analysed using the Review
Manager Software (RevMan 2011). Meta-analysis will be conducted using the inverse variance
method. A random-effect model will be used. Separate meta-analyses will be presented for
specific populations or interventions if statistically significant heterogeneity is explained by some
of these, or if a convincing subgroup effect is found.
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ebruary 2016. Dow
nloaded from
For peer review only
For any outcomes which insufficient data are found for meta-analysis, a narrative
synthesis will be presented.
Subgroup analysis and investigation of heterogeneity
The following subgroups will be investigated, if possible:
- Age (<60 versus >60 years)
- Gender
- Socioeconomic status
Sensitivity analysis
We will use sensitivity analysis to assess the impact on the overall treatment effects of
inclusion of trials which do not report an intention to treat analysis, have high rates of participant
attrition, or with other missing data.
Confidence in cumulative evidence
The quality of evidence for all outcomes will be judged using the Grading of
Recommendations Assessment, Development and Evaluation working group methodology (GRADE
Working Group). The certainty of evidence will be assessed across the domains of risk of bias,
consistency, directness, precision and publication bias.
Certainty will be adjudicated as high, moderate, low, or very low.
1. REGISTRATION
In accordance with the guidelines, our systematic review protocol was registered with the
International Prospective Register of Systematic Reviews (PROSPERO) on 02 June 2015 with the
registration number: CRD42015022086.
2. CONTRIBUTIONS
GR is the guarantor. CS and CL drafted the manuscript. DV is the technical advisor on
implant-supported prostheses. All authors contributed to the development of the manuscript. All
authors devised the MEDLINE search strategy. All authors read, provided feedback and approved
the final manuscript.
3. ACKNWOLEDGEMENT
Maria Teresa Olivares contributed to devise the search strategy for MEDLINE.
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4. AMENDMENTS
If we need to amend this protocol, we will give the date of each amendment, describe the
change and give the rationale in this section. Changes will not be incorporated into the protocol.
5. SPONSOR
No funding has been received for this study. Article processing charges will be covered by
Epidemiology MSc program, Pontificia Universidad Católica de Chile
6. REFERENCES
1. Emami E, De Souza RF, Kabawat M, Feine JS. The impact of edentulism on oral and general
health. Int J Dent. 2013;2013.
2. Locker, D, “Measuring oral health: a conceptual framework,” Community Dental Health. 1988;
5(1): 3-18.
3. Caetano CR, Consani RLX, Bacchi A, Correr AB, dos Santos MBF. Influence of different flask
systems on tooth displacement and framework misfit in mandibular fixed implant-supported
complete dentures. J Prosthodont Res. 2013;57(3):213–8.
4. Prithviraj D, Madan V, Harshamayi P, Kumar CG, Vashisht R. A comparison of masticatory ef fi
ciency in conventional dentures , implant retained or supported overdentures and implant
supported fi xed prostheses : A literature review. 2014;4:153–7.
5. Papaspyridakos P, Mokti M, Chen CJ, Benic GI, Gallucci GO, Chronopoulos V. Implant and
Prosthodontic Survival Rates with Implant Fixed Complete Dental Prostheses in the Edentulous
Mandible after at Least 5 Years: A Systematic Review. Clin Implant Dent Relat Res. 2013;705–17.
6. Barão V a R, Delben J a., Lima J, Cabral T, Assunção WG. Comparison of different designs of
implant-retained overdentures and fixed full-arch implant-supported prosthesis on stress
distribution in edentulous mandible - A computed tomography-based three-dimensional finite
element analysis. J Biomech. 2013;46(7):1312–20.
7. Bedrossian E, Sullivan RM, Fortin Y, Malo P, Indresano T. Fixed-Prosthetic Implant Restoration of
the Edentulous Maxilla: A Systematic Pretreatment Evaluation Method. J Oral Maxillofac Surg.
2008;66(1):112–22.
8. Preciado A, Del Río J, Lynch CD, Castillo-Oyagüe R. A new, short, specific questionnaire (QoLIP-
10) for evaluating the oral health-related quality of life of implant-retained overdenture and
hybrid prosthesis wearers. J Dent. 2013;41(9):753–63.
9. Kwon T, Bain P a., Levin L. Systematic review of short- (5-10 years) and long-term (10 years or
more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants. J
Page 8 of 9
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jopen.bmj.com
/B
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ebruary 2016. Dow
nloaded from
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Dent [Internet]. Elsevier Ltd; 2014;42(10):1228–41. Available from:
http://dx.doi.org/10.1016/j.jdent.2014.05.016
10. Higgins JPT, Altman DG, Sterne JAC (editors). Chapter 8: Assessing risk of bias in included
studies. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of
Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Disponible
en www.cochrane-handbook.org.
11.The GRADE Working Group. List of GRADE working group publications and grants.
http://www.gradeworkinggroup.org/index.htm (accessed 18 Jun 2015).
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jopen.bmj.com
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MJ O
pen: first published as 10.1136/bmjopen-2015-009288 on 23 F
ebruary 2016. Dow
nloaded from
For peer review only
Impact of fixed implant-supported prostheses in edentulous
patients: protocol for a systematic review
Journal: BMJ Open
Manuscript ID bmjopen-2015-009288.R1
Article Type: Protocol
Date Submitted by the Author: 26-Oct-2015
Complete List of Authors: López, Carolina; Pontificia Universidad Catolica de Chile, Faculty of Medicine Saka, Constanza; Pontificia Universidad Católica de Chile, Faculty of Medicine Rada, Gabriel; Pontificia Universidad Católica de Chile, Evidence-based Health Care Program, Faculty of Medicine Valenzuela, Daniela; Universidad de Concepción, Centro de Rehabilitación Oral Avanzada e Impalantologia (CRAI)
<b>Primary Subject Heading</b>:
Dentistry and oral medicine
Secondary Subject Heading: Rehabilitation medicine, Evidence based practice, Geriatric medicine, Patient-centred medicine, Dentistry and oral medicine
Keywords: ORAL MEDICINE, THERAPEUTICS, GERIATRIC MEDICINE, REHABILITATION MEDICINE
For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml
BMJ Open on M
arch 18, 2020 by guest. Protected by copyright.
http://bmjopen.bm
j.com/
BM
J Open: first published as 10.1136/bm
jopen-2015-009288 on 23 February 2016. D
ownloaded from
For peer review only
Impact of fixed implant-supported prostheses in edentulous
patients: protocol for a systematic review
López S., Carolina1,
Saka, H., Constanza1
Rada, Gabriel1,2,3
Valenzuela, D., Daniela4
1
Faculty of Medicine, Pontificia Universidad Católica de Chile.
2 Evidence-based Health Care Program, Faculty of Medicine, Pontificia Universidad Católica de
Chile
3 Epistemonikos foundation
4 Centro de Rehabilitación Oral Avanzada e Impalantologia (CRAI), Universidad de Concepción
Lira 63, Santiago-Chile
Emails:
Carolina López: [email protected]
Constanza Saka: [email protected]
Gabriel Rada: [email protected]
Daniela Valenzuela: [email protected]
Corresponding author: Gabriel Rada
ABSTRACT
Introduction
Edentulism is a debilitating and irreversible condition described as the “final marker of disease
burden for oral health”. Therapy with dental implants is being used on a large scale to replace
missing teeth and to rehabilitate edentulous patients with overdentures and implant-supported
fixed dentures as a method for solving the problem of instability and lack of retention associated
with conventional removable prosthesis. Fixed implant-supported prosthesis are an alternative for
implant rehabilitation treatment that allow patient to have a new fixed teeth. They can be
indicated in partial or total edentulous and they can replace single teeth, or teeth and supporting
tissues (hybrid prosthesis). They overcome the limitations of conventional dentures, increasing
stability and retention, providing functional and psychological advantages for the patients.
Methods and analysis
We will electronically search for randomised controlled trials evaluating the effects of fixed
implant-supported prostheses in edentulous patients in the following databases:
Pubmed/MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials.
We will also try to obtain literature screening references of included studies, searching for trial
protocols in the WHO International Clinical Trials Registry Platform, reviewing International Team
for Implantology conference proceedings and searching for non-published studies through Open
Gray.
Page 1 of 12
For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml
BMJ Open
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960
on March 18, 2020 by guest. P
rotected by copyright.http://bm
jopen.bmj.com
/B
MJ O
pen: first published as 10.1136/bmjopen-2015-009288 on 23 F
ebruary 2016. Dow
nloaded from
For peer review only
Two researchers will independently undertake selection of studies, data extraction and
assessment of the quality of included studies.
Data synthesis and subgroup analyses will be performed using special Review Manager software.
Data will be combined in a meta-analysis using a random effects model. Results will be presented
as risk ratios for dichotomous data and as mean difference or standardized mean difference for
continuous data.
Ethics and dissemination
No ethics approval is considered necessary. Results of this study will be disseminated via peer-
reviewed publications and social networks.
Registration number PROSPERO: CRD42015022086
Strengths and limitations of this study
This will be the first systematic review to assess the impact of implant-supported prostheses in
edentulous patients on their oral health, quality of life and satisfaction. It aims to provide a high-
quality synthesis of current evidence for patients and clinicians about this question. The main
limitation is the heterogeneity of studies available on the subject and the subsequent possibility to
group them to analyze the evidence on each outcome of interest that we have defined.
Keywords: Dental Prosthesis, Implant-Supported, Denture, Complete, quality of life, patients’ satisfaction
INTRODUCTION
Description of the condition
Edentulism is a debilitating and irreversible condition described as the “final marker of
disease burden for oral health”. Although the prevalence of complete tooth loss has declined over
the last decade, it remains a major disease worldwide, especially among older adults (1). Many
factors influence the prevalence of edentulism between different countries and regions, such as
education, economic status, access and opportunity to oral health care, lifestyle and attitudes to
dental care. Edentulism can lead directly to impairment, functional limitation, physical,
psychological and social disability (2), affecting general and oral health of individuals and, therefore,
their quality of life.
Complete denture therapy has become the conventional and most prescribed treatment
option for edentulous patients, providing improved esthetics and function (3). However, bone
resorption of the alveolar ridge, as a consequence of edentulism, brings lack of denture stability
and retention, especially for the lower prosthesis, reducing patient’s comfort, chewing, phonetics
and esthetics. Patients wearing conventional removable prosthesis often complain about the
instability of their dentures. This leads to a feeling of insecurity, inefficient mastication and overall
dissatisfaction with their prosthesis (4).
Therapy with dental implants is being used on a large scale to replace missing teeth and to
rehabilitate edentulous patients with overdentures and implant-supported fixed dentures (3).
Placement of endosseous dental implants to retain and support overdentures or fixed complete
dentures has been developed as a method for solving the problem of instability and lack of
retention associated with conventional removable prosthesis (4). Improvement of retention and
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stability of the prosthetic rehabilitation through implant-supported prosthesis leads to enhance
speaking, swallowing and mastication ability and, therefore, improves patients comfort and
satisfaction.
Description of the intervention
Dental implants represent a proven treatment modality for restoration of edentulous jaws
(5). Several factors play role on the decision between fixed and removable implant dentures such as
inter-foraminal space, inter-jaw relationship, oral hygiene, costs and patient preferences (6).
Fixed implant-supported prosthesis are an alternative for implant rehabilitation treatment
that allow patient to have a new fixed teeth. They can be indicated in partial or total edentulous
and they can replace single teeth, or teeth and supporting tissues (hybrid prosthesis). Selection of
one type or another depends on the patient bone volume and soft tissue conditions (7) in addition
to economic factors and treatment cost. Fixed full-arch implant supported prosthesis may be
either screw or cement retained and are indicated in the presence of enough bone and inter-arch
space (6). Clinical factors that may discard a fixed restoration are mostly related to bone or soft
tissues deficiencies. For this instance, rehabilitation can be done by hybrid prosthesis.
Hybrid prosthesis are fixed rehabilitation composed of a metal-based framework covered
with complete denture components (resin and denture teeth), which is screwed onto the implants
or the abutments. This treatment modality allows patients to have a completely fixed prosthesis,
which can only be removed by a dental professional (8,9).
How the intervention might work
Fixed implant restorations are totally implant supported, with no transference of load to
denture-bearing areas, thus avoiding the possibility of further resorption, associated with tissue-
borne prosthesis (7). They also overcome the limitations of conventional dentures, increasing
stability and retention of the prosthetic rehabilitation and thus, improving speaking, swallowing
and chewing efficiency. This brings functional and psychological advantages for the patients,
enhancing their comfort and self-confidence.
Why it is important to do this review
Previous systematic reviews have addressed the impact of fixed prostheses in partial or
total edentulous persons in terms of survival and success (Kwon, 2014; Papaspyridakos, 2014;
Pjetursson, 2012¸ Lambert 2009), and biological and technical complications (Papaspyridakos,
2012; Pjetursson, 2012; Bozini 2011). However, none of these reviews have assessed the
subjective effects of fixed implant-supported prosthesis in edentulous patients. So, we not only
aim to update existing reviews, but also to supplement existing evidence by incorporating other
impact indicators such as satisfaction and quality of life.
Objectives
Our main objective is to evaluate the effects of fixed implant-supported prostheses in
edentulous patients and to assess their impact on satisfaction and quality of life when compared
to conventional prosthesis or overdentures.
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METHODS
Criteria for considering studies for this review
Types of studies
Type of studies
We will include randomised controlled trials.
Types of participants
We will include studies examining healthy edentulous patients or with stabilized conditions.
Type of interventions
The interventions of interest are full-arched fixed prosthesis and hybrid prosthesis. We will not
restrict by type and number of implants or attachment system.
Comparisons of interest are conventional prosthesis and implant-supported or implant-retained
overdentures.
Types of outcomes
• Primary outcomes:
- Patient satisfaction
- Quality of life
• Secondary outcomes:
- Clinician’s appraisals for treatment success
- Cost
- Technical complications
Search methods for identification of studies
Electronic searches
We will search MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials with no
language or publication restrictions:
The following strategy will be used to search MEDLINE (PubMed):
#1 "Dental Prosthesis, Implant-Supported"[Mesh]
#2 (Dental OR denture*) AND Prosthes* AND ((Implant NEAR Supported) OR Implant-
Supported)
#3 (Dental OR denture*) AND Prosthes* AND ((Implant NEAR fixed) OR Implant-fixed)
#4 (Dental OR denture*) AND Prosthes* AND ((full-arch NEAR fixed) OR full-arch)
#5 (Dental OR denture*) AND Prosthes* AND (hybrid)
#6 #1 OR #2 OR #3 OR #4 OR #5
#7 "Mouth, Edentulous"[Mesh]
#8 "Jaw, Edentulous"[Mesh]
#9 toothless [tiab]
#10 edentul*[tiab]
#11 #7 OR #8 OR #9 #10
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#12 randomized controlled trial [pt]
#13 controlled clinical trial [pt]
#14 randomized [tiab]
#15 placebo [tiab]
#16 randomly [tiab]
#17 trial [tiab]
#18 groups [tiab]
#19 #12 OR #13 OR #14 OR #15 OR #16 OR #17 OR #18
#20 animals [mh] NOT humans [mh]
#21 #19 NOT #20
#22 #6 AND #11 AND #21
The MEDLINE strategy will be adapted to the syntax and subject headings of the other
databases.
The electronic search will be supplemented by:
- Reviewing for additional relevant studies in references of included studies.
- Searching for trial protocols through the WHO International Clinical Trials Registry
Platform.
- Searching in International Team for Implantology conference proceedings
- Searching for unpublished studies through Open Grey.
Data collection and analyses
Deduplicated results of literature will be uploaded to Covidence software
(www.covidence.org).
Selection of studies
Two authors will independently screen the titles and abstracts yielded by the search
against the inclusion criteria. We will obtain full reports for all titles that appear to meet the
inclusion criteria or where there is any uncertainty. We will seek additional information from study
authors where necessary to resolve questions about eligibility. We will resolve disagreement
through discussion. We will record the reasons for excluding trials.
Extraction and management of data
Using standardized forms two reviewers will extract data independently from each
included study. To ensure consistency, we will conduct calibration exercises before starting the
review. Data abstracted will include demographic information, methodology, population, and
intervention, comparison and outcome details.
We will resolve disagreements by discussion, and one arbitrator will adjudicate unresolved
disagreements.
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Risk of bias in individual studies
Two reviewers will independently assess risk of bias using the Cochrane Collaboration tool
for assessing risk of bias (10) which considers random sequence generation, allocation concealment,
blinding of participants, personnel and outcomes, incomplete outcome data, selective outcome
reporting, and other sources of bias. A judgment will be made from the extracted information,
rated as ‘high risk’ or ‘low risk’.
If there is insufficient detail reported in the study we will judge the risk of bias as ‘unclear’
and the original study investigators will be contacted for more information. Disagreements will be
resolved first by discussion and then by consulting a third author for arbitration. We will compute
graphic representations of potential bias within and across studies using RevMan 5.1 (Review
Manager 5.1).
Measures of treatments effects
For dichotomous outcomes we will express the estimate of treatment effect of an
intervention as risk ratios (RR) (improved patient satisfaction/not) together with 95% confidence
intervals (CIs). For continuous outcomes we will use mean difference and standard deviation to
summarize the data and 95% CIs. Where continuous outcomes are measured using different
scales, the treatment effect will be expressed as a standardized mean difference (SMD) with 95%
CI.
Dealing with missing data
Where possible, we will attempt to contact the original authors of the study to obtain any
missing data. If important numerical missing data cannot be obtained, an imputation method will
be used.
Assessment of heterogeneity
We will assess the variations in treatment effect from the different trials by means of a
formal statistical test (Q statistic) and the I2
statistic. We will consider heterogeneity statistically
significant if the P value is < 0.1. A rough guide to the interpretation of the I2 statistic given in the
Cochrane Handbook is: 0 to 40% might not be important, 30 to 60% may represent moderate
heterogeneity, 50 to 90% may represent substantial heterogeneity, 75 to 100% considerable
heterogeneity.
Data synthesis
We will only conduct a meta-analysis if there are studies sufficiently homogeneous in
terms of design, population, interventions and comparators reporting the same outcome
measures.
The results for clinically homogeneous studies will be meta-analysed using the Review
Manager Software (RevMan 2011). Meta-analysis will be conducted using the inverse variance
method. A random-effect model will be used. Separate meta-analyses will be presented for
specific populations or interventions if statistically significant heterogeneity is explained by some
of these, or if a convincing subgroup effect is found.
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For any outcomes which insufficient data are found for meta-analysis, a narrative
synthesis will be presented.
Subgroup analysis and investigation of heterogeneity
The following subgroups will be investigated, if possible:
- Age (<60 versus >60 years)
- Gender
- Socioeconomic status
Assessment of reporting biases
We will investigate the presence of publication bias visually with the use of funnel plots.
We will base evidence of asymmetry on p < 0.10, and present intercepts with 90% CIs. Other
reporting biases, including outcome reporting bias, will be evaluated through discrepancies
between the registered protocol and the final publication. If we cannot find the record of a study
in the WHO International Clinical Trials Registry Platform, we will contact authors for more
information.
Sensitivity analysis
We will use sensitivity analysis to assess the impact on the overall treatment effects of
inclusion of trials which do not report an intention to treat analysis, have high rates of participant
attrition, or with other missing data.
Confidence in cumulative evidence
The quality of evidence for all outcomes will be judged using the Grading of
Recommendations Assessment, Development and Evaluation working group methodology (GRADE
Working Group) (11). The certainty of evidence will be assessed across the domains of risk of bias,
consistency, directness, precision and publication bias.
Certainty will be adjudicated as high, moderate, low, or very low.
1. REGISTRATION
In accordance with the guidelines, our systematic review protocol was registered with the
International Prospective Register of Systematic Reviews (PROSPERO) on 02 June 2015 with the
registration number: CRD42015022086.
2. CONTRIBUTIONS
GR is the guarantor. CS and CL drafted the manuscript. DV is the technical advisor on
implant-supported prostheses. All authors contributed to the development of the manuscript. All
authors devised the MEDLINE search strategy. All authors read, provided feedback and approved
the final manuscript.
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3. ACKNOWLEDGEMENT
Maria Teresa Olivares contributed to devise the search strategy for MEDLINE.
4. AMENDMENTS
If we need to amend this protocol, we will give the date of each amendment, describe the
change and give the rationale in this section. Changes will not be incorporated into the protocol.
5. SPONSOR
No funding has been received for this study. Article processing charges will be covered by
Epidemiology MSc program, Pontificia Universidad Católica de Chile
6. REFERENCES
1. Emami E, De Souza RF, Kabawat M, Feine JS. The impact of edentulism on oral and general
health. Int J Dent. 2013;2013.
2. Locker, D, “Measuring oral health: a conceptual framework,” Community Dental Health. 1988;
5(1): 3-18.
3. Caetano CR, Consani RLX, Bacchi A, Correr AB, dos Santos MBF. Influence of different flask
systems on tooth displacement and framework misfit in mandibular fixed implant-supported
complete dentures. J Prosthodont Res. 2013;57(3):213–8.
4. Prithviraj D, Madan V, Harshamayi P, Kumar CG, Vashisht R. A comparison of masticatory ef fi
ciency in conventional dentures , implant retained or supported overdentures and implant
supported fi xed prostheses : A literature review. 2014;4:153–7.
5. Papaspyridakos P, Mokti M, Chen CJ, Benic GI, Gallucci GO, Chronopoulos V. Implant and
Prosthodontic Survival Rates with Implant Fixed Complete Dental Prostheses in the Edentulous
Mandible after at Least 5 Years: A Systematic Review. Clin Implant Dent Relat Res. 2013;705–17.
6. Barão V a R, Delben J a., Lima J, Cabral T, Assunção WG. Comparison of different designs of
implant-retained overdentures and fixed full-arch implant-supported prosthesis on stress
distribution in edentulous mandible - A computed tomography-based three-dimensional finite
element analysis. J Biomech. 2013;46(7):1312–20.
7. Bedrossian E, Sullivan RM, Fortin Y, Malo P, Indresano T. Fixed-Prosthetic Implant Restoration of
the Edentulous Maxilla: A Systematic Pretreatment Evaluation Method. J Oral Maxillofac Surg.
2008;66(1):112–22.
8. Preciado A, Del Río J, Lynch CD, Castillo-Oyagüe R. A new, short, specific questionnaire (QoLIP-
10) for evaluating the oral health-related quality of life of implant-retained overdenture and
hybrid prosthesis wearers. J Dent. 2013;41(9):753–63.
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9. Kwon T, Bain P a., Levin L. Systematic review of short- (5-10 years) and long-term (10 years or
more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants. J
Dent [Internet]. Elsevier Ltd; 2014;42(10):1228–41. Available from:
http://dx.doi.org/10.1016/j.jdent.2014.05.016
10. Higgins JPT, Altman DG, Sterne JAC (editors). Chapter 8: Assessing risk of bias in included
studies. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of
Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Disponible
en www.cochrane-handbook.org.
11.The GRADE Working Group. List of GRADE working group publications and grants.
http://www.gradeworkinggroup.org/index.htm (accessed 18 Jun 2015).
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PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) 2015 checklist: recommended items to
address in a systematic review protocol*
Section and topic Item No Checklist item
ADMINISTRATIVE INFORMATION Title: Impact of fixed implant-supported prostheses in edentulous patients: protocol for a systematic review
Identification 1a Identify the report as a protocol of a systematic review: YES. Identified as protocol in the title.
Update 1b If the protocol is for an update of a previous systematic review, identify as such. This is the first document and not an
update
Registration 2 If registered, provide the name of the registry (such as PROSPERO) and registration number. PROSPERO reference
CRD42015022086
Authors:
Contact 3a Provide name, institutional affiliation, e-mail address of all protocol authors; provide physical mailing address of
corresponding author. YES. Names, affiliations and emails of all authors provided. Physical mailing address of
corresponding author provided.
Contributions 3b Describe contributions of protocol authors and identify the guarantor of the review. YES. Contributions and guarantor
described in page 7
Amendments 4 If the protocol represents an amendment of a previously completed or published protocol, identify as such and list changes;
otherwise, state plan for documenting important protocol amendments. This is the original protocol. Important protocol
amendments will be documented and submitted to the registering body in compliance with PROSPERO registration
Support:
Sources 5a Indicate sources of financial or other support for the review. Yes. Described in page 8
Sponsor 5b Provide name for the review funder and/or sponsor. Yes. Described in page 8
Role of sponsor or funder 5c Describe roles of funder(s), sponsor(s), and/or institution(s), if any, in developing the protocol. Yes. Described in page 8
INTRODUCTION
Rationale 6 Describe the rationale for the review in the context of what is already known. Yes. Described in pages 2 and 3.
Objectives 7 Provide an explicit statement of the question(s) the review will address with reference to participants, interventions,
comparators, and outcomes (PICO). Yes. Described in page 3.
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METHODS
Eligibility criteria 8 Specify the study characteristics (such as PICO, study design, setting, time frame) and report characteristics (such as years
considered, language, publication status) to be used as criteria for eligibility for the review. Yes. Described under
‘Methods/Criteria for considering studies for this review’ in page 4.
Information sources 9 Describe all intended information sources (such as electronic databases, contact with study authors, trial registers or other
grey literature sources) with planned dates of coverage. Yes. Described under ‘Methods/Search methods for
identification of studies’ in page 4.
Search strategy 10 Present draft of search strategy to be used for at least one electronic database, including planned limits, such that it could be
repeated. Yes. Described under ‘Methods/Search methods for identification of studies’ in pages 4 and 5.
Study records:
Data management 11a Describe the mechanism(s) that will be used to manage records and data throughout the review. Yes. Described in page 5.
Selection process 11b State the process that will be used for selecting studies (such as two independent reviewers) through each phase of the
review (that is, screening, eligibility and inclusion in meta-analysis). Yes. Described in page 5.
Data collection process 11c Describe planned method of extracting data from reports (such as piloting forms, done independently, in duplicate), any
processes for obtaining and confirming data from investigators. Yes. Described in page 5.
Data items 12 List and define all variables for which data will be sought (such as PICO items, funding sources), any pre-planned data
assumptions and simplifications. Yes. Described in page 5.
Outcomes and prioritization 13 List and define all outcomes for which data will be sought, including prioritization of main and additional outcomes, with
rationale. Yes. Described under ‘Methods/Criteria for considering studies for this review’ in page 4.
Risk of bias in individual studies 14 Describe anticipated methods for assessing risk of bias of individual studies, including whether this will be done at the
outcome or study level, or both; state how this information will be used in data synthesis. Yes. Described under
‘Methods/ Risk of bias in individual studies’ in page 6.
Data synthesis 15a Describe criteria under which study data will be quantitatively synthesised. Yes. Described under ‘Methods/Data
synthesis ’ in pages 6 and 7.
15b If data are appropriate for quantitative synthesis, describe planned summary measures, methods of handling data and
methods of combining data from studies, including any planned exploration of consistency (such as I2, Kendall’s τ). Yes.
Described in pages 6 and 7.
15c Describe any proposed additional analyses (such as sensitivity or subgroup analyses, meta-regression). . Yes. Described
under ‘Methods/Subgroup analysis and investigation of heterogeneity’ and under ‘Methods/sensitivity analysis’ in
pages 6 and 7
15d If quantitative synthesis is not appropriate, describe the type of summary planned. Yes. Described under ‘Methods/Data
synthesis ’ in page 7.
Meta-bias(es) 16 Specify any planned assessment of meta-bias(es) (such as publication bias across studies, selective reporting within
studies). Yes. Described under ‘Methods/Assessment of reporting biases’ in page 7.
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Confidence in cumulative evidence 17 Describe how the strength of the body of evidence will be assessed (such as GRADE). Yes. Described under
‘Methods/confidence in cumulative evidence ’ in page 7.
From: Shamseer L, Moher D, Clarke M, Ghersi D, Liberati A, Petticrew M, Shekelle P, Stewart L, PRISMA-P Group. Preferred reporting items for systematic review and
meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ. 2015 Jan 2;349(jan02 1):g7647.
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