Apical Size and Root Canal Treatment Success Trial (AS-RCT Trial)



Status:Recruiting
Healthy:No
Age Range:18 - 85
Updated:2/14/2018
Start Date:August 5, 2016
End Date:April 30, 2022
Contact:Vanessa Chrepa, DDS, MS
Email:chrepa@uw.edu
Phone:2066857965

Use our guide to learn which trials are right for you!

Impact of Final Apical Size Preparation on Root Canal Treatment Success: A Clinical, Microbiological and Volumetric Evaluation

This study is looking into two different ways to perform a root canal treatment. The study
will look at differences and compare the two different treatment options over a 2-year
period.More specifically, this study evaluates a small "skinny" root canal shape compared to
a larger "broad" root canal shape and if this affects the success of the root canal
treatment. Both types of treatment are standard of care and aim to treat the infection inside
your tooth. When a tooth is infected with bacteria, we can see a dark area on the radiograph
around the roots of the infected tooth. If this dark area becomes smaller or goes away
completely after root canal treatment and you do not feel any pain or other symptoms, then we
know that the treatment was successful and there is no need for further treatment on this
tooth. To measure the size of the dark area around the tooth (i.e. volume) before and after
the treatment we will need to take two limited volume three-dimensional radiographs (cone
beam computed tomography-CBCT), one prior to treatment and one at two years after the root
canal treatment is completed. These radiographs are more accurate in detecting changes in
lesion size than the regular periapical radiographs. We will assess the changes in lesion
volume for all teeth included in the study and that will help us find differences in success
between the two root canal treatment protocols, We are specifically looking for persons that
have been diagnosed with a necrotic permanent mandibular molar with an evident radiographic
lesion (i.e. dark area around the tooth) that can be retained in the mouth with root canal
treatment and permanent restoration. This study place participants in different treatment
groups after randomization. Randomization means that you are placed by chance (like flipping
a coin) into a treatment group. For this study, there are two treatment groups (protocol) and
they are listed below.

Protocol 1: Group S: Root canal treatment will be performed in 2-visits using hand files and
rotary instruments to a final canal shape of size #25.

Protocol 2: Group L: Root canal treatment will be performed in 2-visits using hand files and
rotary instruments to a final canal shape of size #35

We will perform a randomized, blinded clinical trial with clinical, microbiological and
volumetric outcomes. The study population will be selected from adult patients in need of
endodontic treatment on mandibular molars diagnosed with pulp necrosis and presenting with a
visible radiographic lesion associated with at least the mesial root. Patients will be
randomized into one of the two arms (group S: apical size#25; group L: apical size#35) and
followed for 2 years post-treatment.

Treatment sequence Endodontic residents under the direct supervision of a study investigator
will perform all treatments; all providers will be trained and calibrated for root canal
treatment protocol and microbial sample collection. The calibration session will be repeated
annually until completion of the study.

Treatment protocol First Appointment

1. Pre-operative CBCT will be obtained and baseline clinical signs and symptoms will be
recorded. Pain level will be recorded on a 0-10 visual analog scale (VAS).

2. After ascertaining adequate local anesthesia, rubber dam isolation will be obtained and
the field will be disinfected with 3% hydrogen peroxide and 2.5% sodium hypochlorite
(NaOCl) solution as previously described (37).

3. Access will be performed and the operative field will be again disinfected with 2.5%
NaOCl followed by 5% sodium thiosulphate. A microbiological sample (S0) of the field
will be obtained with paper points. S0 will be used as a negative control (i.e.
sterility sample).

4. The mesial canal walls will then be touched lightly with hand files to disrupt bacterial
biofilms and a microbiological specimen (S1) will be obtained (described in detail
below).

5. Orifice will be enlarged with a Protaper Universal SX rotary file (Dentsply, Tulsa, OK)
Apical patency will be determined with a size #10 hand file and working length will be
obtained with the use of Root ZX apex locator (J Morita USA, Irving, CA) and verified
with a PA radiograph.

6. Coronal 2/3 of mesial canal WL will be instrumented with Vortex Blue rotary file 25/06
(Dentsply). First apical binding file (FABF) will be recorded at this stage to serve as
a covariable in the analyses.

7. Apical 1/3 instrumentation of mesial canals will be carried out according to assigned
group as follows:

1. Group S: Instrumentation technique to working length (WL) using the sequence 15/04 →20/04
→25/04 →25/06 Vortex Blue rotary file system (Dentsply).

2. Group L: Instrumentation technique to WL using the sequence 15/04 →20/04 →25/04 →25/06 →
30/04 →35/04 Vortex Blue rotary file system (Dentsply).

8. Distal(s) canal instrumentation will be standardized for both groups as follows:

1. Coronal 2/3 of distal canal will be instrumented with Vortex Blue rotary file 25/06 2.
Apical instrumentation to WL using the sequence 15/04 →20/04 →25/04 →25/06 → 30/04
→35/04→40/04 Vortex Blue rotary file system (Dentsply) 9. The canals will be irrigated using
a 30-gauge side-vented needle with 6% NaOCl (10ml/canal) followed by 17%
ethylenediaminetetraacetic acid (EDTA; 5ml/canal) followed by a final rinse of 6% NaOCl
(10ml/canal) and 5% sodium thiosulfate (2ml/canal).

10. A microbiological specimen (S2) will be obtained from mesial canals, and then the canals
will be dried with paper points.

11. Calcium hydroxide [Ca(OH)2] will be placed as an interim intracanal medicament and a
temporary restoration consisted of Fuji II LC (GC Corp, Tokyo, Japan) will be placed in the
access. A post-op radiograph will be made.

Second appointment (within 10-14 days)

1. Clinical signs and symptoms will be recorded. Pain level will be recorded on a VAS.

2. After ascertaining adequate local anesthesia, rubber dam isolation will be obtained and
the field will be disinfected as described above.

3. Root canal system will be accessed and a second sterility microbiological sample will be
obtained (S00).

4. Ca(OH)2 will be removed by irrigating with 6% NaOCl (10ml/canal) followed by 17% EDTA
(5ml/canal) and a final rinse of 6% NaOCl (10ml/canal). This will be followed by
irrigation with 5% sodium thiosulfate (2ml/canal).

5. A microbiological specimen (S3) will be obtained from mesial canals, and then the canals
will be dried with paper points.

6. Final obturation will be performed with gutta-percha and AH+ sealer utilizing the
continuous wave condensation technique.

7. Access will be restored permanently and patient will be referred to their dentist for
full coverage restoration. Adequate existing full coverage restorations will remain in
place. A post-op radiograph will be made.

Inclusion Criteria:

- Healthy adults 18-85 years old, ASA I, II

- Mandibular molars with diagnosis of necrotic pulp and periapical lesion associated
with at least the mesial root

- Lesion with Periapical Index score > 2 and largest lesion dimension <10mm

- Fully developed apices and patent root canals, good periodontal health (probing depth
< 4mm)

- Confirmed restorability with crown restoration after root canal treatment or adequate
existing full cuspal coverage restoration

Exclusion Criteria:

- ASA Class III or IV, immune-compromised patients, pregnant women, history of diabetes
or bisphosphonate treatment

- Teeth with coronal cracks that extend below the CEJ, or with non-odontogenic
periapical pathology and/or with not fully developed apices

- Molars with c-shape anatomy or middle medial canal

- Patients unable to present for a recall at one-year and/or two-year post-treatment or
unwilling to participate
We found this trial at
2
sites
San Antonio, Texas 78229
Principal Investigator: Nikita Ruparel, MS DDS PhD
Phone: 210-567-3396
?
mi
from
San Antonio, TX
Click here to add this to my saved trials
1959 Northeast Pacific Street
Seattle, Washington 98195
Phone: 651-395-9491
?
mi
from
Seattle, WA
Click here to add this to my saved trials