Clinical Assessment Of Inlay Retained Bridge Designs
(Tub Shaped And Inlay Shaped)
In Missing Posterior Teeth Cases.
(Randomized clinical trial)
التقييم الاكلينيكي للجسور المثبتة بالترصيع (شكل الحوض و شكل الترصيع) في حالات فقد الاسنان الخلفية.
(دراسه اكلينيكية عشوائيه)
Protocol submitted in partial fulfillment for the requirement of Doctorate Degree in fixed prosthodontics.
By
Mohamed Mahmoud Abdelgawad Abdelfattah
B.D.S Cairo University, 2009
M.D.S Cairo University 2016
Supervisor
Prof. Dr. Omaima Salah El Dein El Mahallawi
Professor, Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Cairo University
Department of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Cairo University
2017
This protocol will be done following the SPIRIT 2013 Checklist 2.
Administrative information
Title: Clinical Assessment Of Inlay Retained Bridge Designs (Tub Shaped And Inlay Shaped) In Missing Posterior Teeth Cases. Randomized Clinical Trial.
Trial registration: on the Pan African Clinical Trial Registry (PACTR)
Protocol version: version 1
Funding: the trial is self-funded whether on a financial or a non-financial basis. Equipment units and some consumables re provided by Fixed prosthodontics department, Faculty Dental Medicine, Cairo University.
Roles and responsibilities:
Name: Mohamed Mahmoud Abdelgawad Abdelfattah (Main researcher)
Affiliation: Assistant lecturer of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Cairo University.
Name: Prof. Dr. Omaima Salah El Dein El Mahallawi (El Mahallawi O)
(main supervisor)
Affiliation: Professor, Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Cairo University
Supervisor direct and guide the practical work of the study and give the last confirmation together with the EBD committee for the methodology of reporting the study and for proceeding to publishing it later on
Trial sponsor: Faculty of Oral and Dental Medicine, Cairo University-Egypt
Steering Committee:
1- Fixed Prosthodontics department board.
2- Research Plan Committee: To make sure that the trial satisfies the research plan of the Faculty and the department and to approve the methodological outcome.
3- Evidence Based Committee, Faculty of Oral and Dental Medicine -Cairo University. To ensure evidence based approval for the methodology and reporting of the trial.
4- Ethics Committee, Faculty of Oral and Dental Medicine -Cairo University.
5- Committee of Higher Education and Scientific Research .
6- Faculty of dentistry Board.
Introduction: –
The PICO question:
P: Missed posterior teeth
I: Tub shaped inlay retained fixed partial denture
C: Inlay shaped inlay retained fixed partial denture
O: Primary outcome: Retention
Secondary outcome: Marginal adaptation, Gingivitis, Caries and Fracture
T: 12 month
S: Randomized clinical trial (RCT).
Measuring
unit Measuring
device Outcome name
Discrete (scores) MUSPHS 9 Retention Primary outcome
Discrete (scores) MUSPHS 9 Marginal adaptation
Secondary outcome
Discrete (scores) Gingival Index 1
Gingivitis
Discrete (scores) MUSPHS 3
Caries
Discrete (scores) MUSPHS 3
Fracture
Formulated question:
In patient with missing single posterior teeth, is inlay retained fixed partial denture with tub shaped preparation design provide equal retention compared to inlay preparation design?
Justification for the study:
A major problem of the conventional porcelain-fused-to-metal and all ceramic prosthesis is the reduction of a high amount of sound tooth substance of the abutment tooth. Although the implant-supported restorations represent a highly-rated replacement for the tooth-supported conventional bridges, patients may deny this treatment option for their very high cost and/or for their surgical requirements. the inlay retained prosthesis offers a less damaging treatment option and also a more conservative modality for restoring a damaged tooth, as it needs minimal amount of tooth removal, so preserves the healthy tooth substance, and also preserve the periodontal structures around the tooth. The inlay bridge preparation show three types of preparation, the inlay shaped, the tub shaped and the proximal box shaped designs. Intracoronal preparation of the inlay retained prosthesis for the abutments (inlay shaped and tub shaped) should show the following criteria: The inlay shaped preparation should show an occlusal-proximal box preparation and to be designed with the line angles should be rounded, smooth and rounded corners, and rectangular flat floor with no beveling for the occlusal and gingival margins. The occlusal inlay preparation should have preparation depth allowed for a thickness of 2.0 mm for the material of the bridge. The occlusal reduction show 4 mm width with extension of 4 or 6 mm mesio distally for the posterior teeth. The tub-shaped reduction consist of an occlusal proximal inlay and prepared as the same geometry as the inlay shaped preparation, except that for the proximal box preparation which is not present in this preparation design. 6
The classic inlay-shaped bridge design showed a high percentage of dislodgment causing failure in the restoration reaching 20% after one year of clinical evaluation, as reported in an article who assessed thirty inlay bridges, after one year clinical service a six inlay bridges were dislodged. 7
The hypothesis of our trial is that the new design may show longer survival rate due to less stress applied on the restoration which allow the restoration to function for longer period.
Rationale for carrying out the trial:
It has been showed that a high amount of dentin is lost during the procedure of preparations of abutment teeth for the conventional full-coverage retained bridges with an overall tooth substance loss calculated 62% to 72% which is considered an aggressive loss of tooth structure and is usually followed with post-operative sensitivity and pain 10. With the inlay retained bridge there is little tooth structure loss which should be accompanied with less post-operative sensibility.
As a result for this finding, this trial will benefit practitioners and clinicians by guiding them to choose a more conservative treatment option with superior fit values which will return to the patient with prolonged survival of the restoration, less chair time and less risk for pulp injury indicating more successful restoration for the practitioner.
Explanation for choice of comparators:
There are different treatment options using the different available materials exist to compensate for a missing tooth in the posterior area of the mouth. If patients not require implant therapy, either with or with no surgical procedures, more conservative options may show an alternative to the conventional less conservative full coverage prosthesis, which need more drastic preparation for the tooth substance.5,8 There are more than one indirect restoration for replacement of missing single posterior teeth, this may include the conventional full coverage bridges, implant supported prosthesis and inlay retained bridges. The last treatment modality can be considered as the least time and least expensive solution when compared to the other alternatives. Resin bonded bridges represent a minimally invasive procedure; pre-existing restorations may minimize the tooth structure reduced and also give more retention and longevity to the inlay bridges, making it an ultraconservative treatment modality. 9
Objectives:
The aim of this study is to clinically assess two inlay retained bridge designs (tub shaped and inlay shaped) used to replace missing posterior teeth cases.
Research hypothesis:
The new design may show longer survival rate due to less reduction for the tooth structure, less plaque accumulation and less trauma to the gingival tissues.
Study design:
In vivo (Randomized clinical trial).
Methods:
This trial will be conducted on patients from the Outpatient clinic in the Fixed Prosthodontics Clinic, Faculty of Oral and Dental Medicine, Cairo University.
Eligibility criteria:
Inclusion criteria:
All subjects are required to be
1) From 18-55 years old, should be able to read and sign the consent document.
2) Ability to tolerate the restorative procedures (physical and psychological).
3) Patients with teeth problems indicated for inlay retained fixed partial denture:
a) Good oral hygiene
b) Low susceptibility to decay
c) Have a minimum coronal tooth height of 5 mm,
d) Parallel abutments
e) Sufficient mesio distal edentulous gap dimensions.
4) With no active periodontal or pulpal problems, with sound teeth or teeth with shallow restorations
5) Willing to return for follow-up visits.
Exclusion criteria
1. Partially erupted teeth (young)
2. Bad oral hygiene and motivation
3. Root canal treated teeth
4. Psychiatric problems or unrealistic expectations
5. Severe parafunctional habits
6. The absence of enamel on the preparation margins
7. Extensive crown defects
8. Abutment mobility
Interventions
The tub-shaped inlay preparation design this consists of an occlusal proximal reduction featuring a 3.5-4 mm width buccolingually, 3-3.5mm depth occluso gingivally and 7-7.5 mm length mesio distally for molars and 2.3-2.8mm width buccolingually, 3-3.5 mm depth occluso gingivally and 3.5-4mm length mesiodistally for premolars. when necessary, superficial extensions may also be made on the preparations so that the occlusal fossa included in the preparation area and then the susceptibility for plaque accumulation will be diminished. 4
Strategies to improve adherence to intervention protocol:
– Adherence session will take place in the presence of the patients in the initial visit. This include that the patient will be informed about the study steps and maintenance of oral hygiene instructions. Participants will be asked about if they have any problems like pain. 2
Relevant concomitant care during the trial:
Motivation and enforcing the maintenance of oral hygiene measures.
Outcomes
The following assessment surveys will be carried out for both groups:
Measuring
unit Measuring
device Outcome name
Discrete (scores) MUSPHS 9 Retention Primary outcome
Discrete (scores) MUSPHS 9 Marginal adaptation
Secondary outcome
Discrete (scores) Gingival Index 1
Gingivitis
Discrete (scores) MUSPHS 3
Caries
Discrete (scores) MUSPHS 3
Fracture
Participant timeline
The visits will be designated as follows:
Visit 1: Preoperative records, face-to-face adherence reminder session, clinical examination, radiographic examination, intraoral photography and primary impressions for diagnostic cast construction.
Visit 2: teeth preparations, secondary impression and temporization.
Visit 3: try in for the restoration.
Visit 4: final cementation of the restoration.
Visit 5: follow up
Schematic diagram:
Study period
Post allocation Allocation Enrollment
T6 T5 T4 T3 T2 T1 T0 Time point
Enrollment
X -Informed consent
X – Eligibility
screening
X -Allocation
Interventions:
X -base line data
X -teeth preparation, secondary impression and temporary restoration
X -try in for the restoration.
X -final cementation of the final restoration.
X -Assessment of the restoration for the outcomes.
Sample size:
As there is no previously published effect size data regarding the effectiveness of the intervention or the control, an estimated sample size of 10 bridges would be used with allocation ratio of 1:1.
Recruitment:
The patients who show the inclusion criteria as mentionedo will be selected from the outpatient clinic of the fixed prosthodontics department – Cairo University. Screening will be carried out for patients until the target population is reached.
Methods: Assignment of interventions:
Sequence generation
The participant will be allocated in to two groups with 1:1 allocation ratio by using computer.
Implementation:
Abdelfattah (the main researcher) will select the patients who show the listed inclusion criteria and divided them into two groups
Blinding
Double blind study
Methods:
Data collection:
Primary outcome: the retention of the restoration for both groups will be assessed using MUSPHS criteria.
Secondary outcome: the marginal fit, caries, fracture and gingivitis for both groups will be assessed using the MUSPHS and gingival index.
Plans to promote participant retention & complete follow-up:
Telephone numbers and addresses of the patients enrolled in the trial will be recorded. All patients will be given a phone call before the next appointment for confirming to their coming.
Data management
All data will be managed electronically. Patient files will be stored in numerical order in a secured place.
Data analysis
All Data will be collected, revised, arranged in tables and entered into the system. Quantitative variables from normal distribution will be expressed as mean and standard deviation (SD) values. To test the significant differences between two groups student t-test will be used. Significant level will be set at P ≤ 0.05. Statistical analysis will be done using Statistical Package for Social Sciences, Version 21.0 (SPSS, IBM, Chicago, III, USA) for Windows.
Data monitoring
Data monitoring is the responsibility for the main supervisor. Interim analysis will be done if harms occur.
Harms
Any harm or adverse events like pain or failure if happened will be recorded, documented and dealed with as recommended.
Auditing
Auditing of the trial design will be commenced by the evidence based committee – Faculty of Oral and Dental medicine – Cairo University.
Ethics and dissemination
Research ethics approval
The protocol and the informed consent template will be reviewed by the ethics committee of scientific research -Faculty of oral and dental medicine – Cairo university.
Protocol amendments
Any modifications to the protocol which may affect the study or the patient, will require a formal amendment to the protocol. Such amendment will be agreed upon by the council of Fixed Prosthodontics Department, Faculty Of Oral And Dental Medicine – Cairo University.
Consent
The researcher will discuss all study aspects with all patients, so patients will be able to have an informed discussion with the researcher. Researcher will obtain written consent from the patients who willing to participate in the study. All consent forms will be in Arabic language (appendix1.1).
Confidentiality
All information related to the study will be stored in a secure place. All patients information will be stored in cabinets in areas with limited access. All data processing forms will be identified by a number to maintain participant confidentiality.
Access to data
Access to the data is allowed to the investigator and supervisors. The participant study information will be confidential.
Ancillary care
All patients will be followed up until the study period is completed. As any prosthetic treatment, post insertion adjustments will be done if necessary and the recall maintenance visits will be arranged.
Dissemination policy
-The results of the study will be published as partial fulfillments for the doctorate degree in fixed prosthodontics.
-Topics from the study suggested for presentation or publication will be circulated to the authors.