Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03064516 |
| Other study ID # |
UNIB2 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
March 20, 2017 |
| Est. completion date |
December 20, 2017 |
Study information
| Verified date |
October 2019 |
| Source |
Universidade Ibirapuera |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Objective: To evaluate the immediate and mediate outcomes of endocrowns and onlay ceramic
restorations with glass fiber pin in endodontically treated teeth. Material and methods: A
randomized controlled clinical trial, a double-blind (patient and examiner) is conducted by
one trained and calibrated operators who perform all restorative procedures. The restorations
are evaluated longitudinally by a blind and calibrated examiner using the USPHS. A total of
20 patients will be randomly assigned to each group for a total of 40 patients. The
randomization sequence will be generated (www.sealedenvelope.com) and to ensure the
confidentiality of the allocation, this will be used opaque, sealed and numbered envelopes in
series. These will be kept with an independent researcher for the moment of inclusion of the
subjects. In the group of onlays, the teeth receive a fiberglass pin in the main root canal
and composite resin filling. In the group of endocrown, only the restoration fill the pulp
chamber. The parts are milled in IPS e-max CAD (Ivoclar Vivadent) and cemented with the
Multilink cementation system (Ivoclar Vivadent). The immediate clinical (focused in
restoration and patient) and mediate (radiographic and clinical) outcomes will be compared
between the groups. Survival and success rates will be defined in 24 months. Survival will be
established by Kaplan-Meier survival curve and log-rank can be conducted to identify as
variables associated with as failures over time. Multivariate analysis with the Cox
regression models will be condutcted for the determination of failure predictors. For all
analyzes, the significance value will be adjusted to 5%.
Description:
Study design - ethical and methodological aspects This study is an integral part of an
umbrella project, in which the primary outcome is the longevity of prosthetic treatments,
whereas patient-centered secondary outcomes are dealt with in the current study. The study
protocol was approved by the Research Ethics Committee, following the Consolidated Standards
of Reporting of Trials (CONSORT and CONSORT PRO) guidelines (Calvert et al., 2013; Moher et
al., 2012), and registered at clinicaltrials.gov (NCT03064516).
This double-blind, parallel-arm randomized clinical trial, with a 1:1 allocation ratio, was
conducted by a previously trained operator, who performed all the restorative procedures.
Survival rate of inlay/onlay ceramic restorations (96.6% after 24 months) was the primary
outcome considered for sample size calculation (Peumans et al., 2010). Therefore, a
clinically significant difference of 15% is expected for longevity between the groups. So,
adopting a significance level of 0.05 and a 0.80 power, considering one tooth per patient,
and using a two-tailed test for noninferiority trials, adding 20% for possible losses
(dropout), the final number of teeth per group was 20, corresponding to a total of 40 teeth.
Participants - recruitment, eligibility, randomization, and allocation The patients were
recruited by one of the researchers (SM) based on history-taking, clinical examination, and
radiographic exams using a sample of patients from the Military Police Dental Center (São
Paulo, Brazil) treated in 2017. The clinical steps were carried out in a private dental
office.
Eligible patients were randomly assigned to one of the parallel arms of the study. The
randomization sequence was generated (www.sealedenvelope.com) and allocation concealment was
ensured by the use of sealed brown envelopes numbered serially and kept in possession of an
independent researcher until they were opened by the operator at the beginning of treatment.
The contents of the envelope indicated the experimental group to which the patient would be
assigned: Endocrown group (test) or Partial coverage ceramic restoration + fiber post group
(PCCR+post- control).
Restorative techniques for the experimental groups All participants received instructions on
oral hygiene and diet. Radiographs were taken at baseline and after cementation. Photographs
were taken at baseline, after removal of the carious tissue and of old restorations, after
cavity preparation, and after cementation. Procedure time was recorded in sessions 1 and 2,
beginning with preoperative mouth rinsing and ending with occlusal adjustment (session 1) and
beginning with preoperative mouth rinsing and ending with final radiograph (session 2).
Session 1- Cavity preparation and casting Endocrown group- Well-defined cervical chamfered
finish lines should be created to facilitate the impression and technical procedures, thus a
2-mm round-ended chamfer finish line was created along the margin using tapered inverted cone
diamond burs, at high rotation and under cooling, against a 1:5 contra angle multiplier
(S-MAX M95L- NSK). No filling was used, the space of the pulp chamber is included in the
preparation.
PCCR+Post group- A fiber post (White post, FGM) whose size was compatible with the main canal
was luted, reaching approximately half of the canal. The post was cleaned with alcohol,
dried, and treated with Monobond (Ivoclar Vivadent); Multilink was applied to the tooth
(Ivoclar Vivadent), mixing it with primer A+B at a 1:1 ratio, without previous acid etching,
with a brief air jet. After that, the post was luted with Multilink resin cement (Ivoclar
Vivadent), followed by photopolymerization for 20 seconds and filling with composite resin -
shade A2 (Tetric N Ceram bulk fill- Ivoclar Vivadent), in 1-2 mm increments and
photopolymerization for 20 seconds per layer. Occlusal and proximal boxes were prepared, not
exceeding 2 mm in ceramic thickness. A 2-mm round-ended chamfer finish line was created along
the margin of extracoronal areas using tapered inverted cone diamond burs, at high rotation
and under cooling, against a 1:5 contra angle multiplier (1:5 S-Max M95L, NSK).
In both groups, the cusps were preserved, whenever possible, but in cases where veneering was
needed, the occlusal surface was abraded to allow for a 1.5-to-2 mm space. If necessary, the
proximal contact point was removed with metal files.
The double-cord technique (Ultrapack- Ultradent) and double molding technique were used
(Virtual heavy and regular body - Ivoclar Vivadent). The color was chosen using the Vita
classical shade guide (Vita Zahnfabrik). The provisional restorations were fabricated with
acrylic resin and cemented with Temp Bond NE (Kerr Corporation).
Laboratory phase - ceramic restoration manufacture The specimens were fabricated with lithium
disilicate glass ceramic (IPS e.max CAD- Ivoclar Vivadent) and milled (Cerec In Lab Mcxl),
producing a monolithic restoration, which was tinted and glazed.
Session 2- Testing, fitting, and cementation of the ceramic restoration After testing and
fitting of the specimen in the mouth, rubber dam isolation was used for adhesive cementation
in both groups, as follows: the enamel and dentin were etched with 37% phosphoric acid gel
(N-etch; Ivoclar Vivadent) for 15-20 seconds, followed by copious rinsing and brief air jets.
The specimens were etched with 5% hydrofluoric acid (IPS Ceramic Etching Gel; Ivoclar
Vivadent), silanized for 1 min (Monobond N; Ivoclar Vivadent) and luted with Tetric N-bond
and Multilink N dual cement (Ivoclar Vivadent). Photoactivation was performed with a
Radii-Cal device (SDI- 1200 mW/cm2) for 20 seconds on each surface. Occlusal adjustment was
performed and the restorations were polished with rubber points (Optra Fine Ivoclar Vivadent)
at low speed, under cooling.
Patient-centered outcomes
Endodontic treatments had been carried out by different dentists on dates that could not be
clearly specified by the patients. Patient-reported outcome measures (PROMs) include
self-administered questionnaires, with the purpose of evaluating psychometric data, in
addition to history taking and demographic and clinical data. The questionnaires described
next were handed out to participants by an external examiner, in the absence of the operator:
- Patient satisfaction questionnaire (Mattos-Silveira et al., 2015) - The patient was
asked to give his/her real opinion about the treatment and to indicate how satisfied
he/she was on a 0-3 scale: 0 - excellent; 1- good; 2- acceptable; 3- not satisfied.
- Visual analog scale- Used to assess patient discomfort/pain immediately after the end of
sessions 1 and 2. This scale consists of a 10-cm (100-mm) horizontal line, with "no
sensitivity" written on one end and "maximum sensitivity" on the other one. The patient
was asked to draw a vertical line on the horizontal scale to indicate his/her level of
discomfort/pain. After that, the distance (in mm) from the starting point (no
sensitivity) to the vertical line drawn by the patient was measured with a ruler (0 to
100 mm). The recorded values were interpreted as follows: 0-4 mm no discomfort; 5-44 mm
mild discomfort; 45-74 mm moderate discomfort; 75-100 maximum discomfort.
Statistical analysis The data were assessed by SPSS V16 for Windows (SPSS; Chicago, IL, USA).
Poisson regression analysis was used to compare patient discomfort between the groups and to
evaluate the influence of explanatory variables on the discomfort reported by patients (age
and sex, tooth, type of restorative treatment, number of treated surfaces, presence of
endodontic lesion, and procedure time). At first, an unadjusted Poisson regression analysis
was performed for each explanatory variable, and values with p<0.20 were included in the
adjusted regression model. Only those variables with p=0.05 were kept in the final model.
Prevalence ratios (PR) were calculated using a 95% confidence interval (95%CI). As the level
of satisfaction was 100% for score 0, it was not possible to conduct a statistical analysis.
Two-way repeated-measures analysis of variance - experimental group and time - was used to
estimate the difference in procedure time between the experimental groups. Kaplan Meyer will
be performed to survival analysis.
In all analyses, the significance level was set at 5%.
