Purpose

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

Category

IRB Number
20180078HU
NCT Number
NCT03053037
Open to Enrollment
Yes
Sponsor
University of Washington -



Study Contact

Local Recruitment Point of Contact
Varvara Chrepa
(210) 567-3381
chrepa@uthscsa.edu

Local Recruitment Point of Contact
Erin Locke
(210) 567-0895
locke@uthscsa.edu

Principal Investigator
Varvara Chrepa

Regulatory Point of Contact
Varvara Chrepa
(210) 567-3381
chrepa@uthscsa.edu

Regulatory Point of Contact
Erin Locke
(210) 567-0895
locke@uthscsa.edu



Eligibility

Eligible Ages
Between 18 Years and 85 Years
Eligible Genders
All
Accepts Healthy Volunteers
Yes

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

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Intervention Model Description
randomized clinical trial 2 arms
Primary Purpose
Treatment
Masking
Double (Participant, Outcomes Assessor)
Masking Description
Similar instrumentation method is used for both groups, therefore participants cannot be aware of the allocation. Data will be de-identified prior to outcome assessment.
Condition
  • Root Canal Therapy
  • Arm Groups

    ArmDescriptionIntervention
    Active Comparator

    Group S

    mesial canals in Group S will be instrumented to size 25
  • Procedure: final apical size instrumentation

    root canal instrumentation to two different final preparation sizes

  • Active Comparator

    Group L

    mesial canals in Group L will be instrumented to size 35
  • Procedure: final apical size instrumentation

    root canal instrumentation to two different final preparation sizes