Plain English Summary
Background and study aims
Root canal treatment is a dental procedure that is used to treat infection at the centre of a tooth. The centre of the tooth is made up of soft tissue called the dental pulp. It includes nerves and blood vessels. The root canal system itself is made up from the dental pulp which extends from the crown of the tooth until the end of the tooth root. If infected, the dental pulp will start to die and the bacteria (and substances that the bacteria release) will eventually pass though and out of the end of the root canal though the tooth root. This can make the tooth painful and can even lead to a tooth (or dental) abscess. One way to treat this is via root canal treatment. This involves removing the decaying dental pulp and therefore the bacteria from the centre of the tooth. The root canal is then filled with a rubber-like material called gutta-percha. The tooth is then sealed with a filing or crown. In order to fill the root canal after removal of the dental pulp, it has to be widened. This is done by using a series of small files. This study is investigating two types of file, comparing the amount of discomfort a patient experiences when treated using the multi-file rotary (Mtwo) system with those treated using the single-file reciprocating [Reciproc (VDW)] system.
Who can participate?
Healthy adults (aged at least 18) that are in need of root canal treatment.
What does the study involve?
Participants are randomly allocated to one of two groups. Those in group 1 are treated using the Mtwo system. Those in group 2 are treated using the VDW system. Immediately after the root canal treatment has been performed, each participant is asked to assess how painful their procedure was, using a scale from 1010 (with 10 being the most painful).
What are the possible benefits and risks of participating?
Not provided at time of registration
Where is the study run from?
Campinas State University (Brazil)
When is the study starting and how long is it expected to run for?
January 2015 to December 2015
Who is funding the study?
National Council for Scientific and Technological Development (Brazil)
Who is the main contact?
Professor Emmanuel Silva
Patient intraoperative discomfort after using rotary or reciprocating systems: a prospective and randomized clinical trial
The hypothesis tested was that there are differences in patients’ intraoperative discomfort among the different root canal treatment instrumentation systems.
Ethics Committee in Research of the Piracicaba Dental School, University of Campinas, 12/2014, ref: 058/2015.
Randomized clinical trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
After local anesthesia with 2% lidocaine with 1:100,000 epinephrine, a rubber dam was placed and the access cavity was prepared using sterile diamond burs. If patients recorded any pain sensation during the procedure, supplemental injection of local infiltration with 1.8 mL 2% lidocaine with 1:100.000 epinephrine was administered.
An initial exploration of the root canals was performed with size 10-K files (VDW), to establish the root canal length using an electronic apex locator (Root ZX II; J. Morita Corp., Tokyo, Japan). Working length (WL) was established by deducting 1 mm from the canal length. Only cases where a 10-K file go passively and a 15-K file did not got passively to the WL in both canals (mesiobuccal and distobuccal canals for maxillary molars; mesiobuccal and mesiolingual canals for mandibular molars) were selected. These cases were classified as small and R25 was recommended, according to the manufacturer´s protocol. All teeth received the two different instrumentation protocols (Mtwo rotary system or Reciproc reciprocation system). A web-based program determined randomized allocation of the instrumentation systems per canal. While the endodontist were not blinded to the allocated file system, patients were kept blinded to the allocation. Instruments were driven with the VDW Silver motor (VDW) according to each manufacturer`s instructions:
1. Reciproc R25 (25/0.08) was introduced into the canal until resistance was felt and then activated in reciprocating motion. The instrument was moved in an apical direction using an in-and-out pecking motion of about 3 mm in amplitude with a light apical pressure. After 3 pecking motions, the instrument was removed from the canal, and its flutes were cleaned off. This procedure was performed until the instrument reached the WL.
2. Mtwo instruments were used according to the manufacturer´s instructions using the follow sequence: 10/0.04, 15/0.05, 20/0.06 and 25/0.06. The motor was adjusted to 500-600 rpm and 1 N/cm2. After 3 gentle in-and-out motion strokes, the instrument was removed from the canal and cleaned until the WL was reached.
In both systems, before each file, 2% Chlorhexidine gel was inserted into root canal. After each file, root canals were irrigated with 2 mL 0.9% saline sterile solution dispensed using a 30-G Max-i-Probe needle (Dentsply-Maillefer) up to 3 mm from the WL. After canal preparation, an additional rinse with 5 mL 0.9% saline solution was performed. The total amount of solution used per canal was 20 mL. A final rinse with 5 mL 17% EDTA delivered for 3 minutes followed by a 5 mL rinse with 0.9% saline solution was performed for both groups. Then, canals were dried with absorbent paper points (VDW) and filled with gutta-percha and Endomethasone N using warm vertical compaction with the continuous-wave technique and gutta-percha backfill. The study was finished when all the selected volunteers had the endodontic treatment completed.
Primary outcome measure
Intraoperative discomfort, measured using the visual analogue score (VAS), during the procedure, between the two different instrumentation groups
Secondary outcome measures
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Healthy (ASA I) adults older than 18 years of age that had been admitted to the Endodontics Department of FOP-UNICAMP, from January 2015 to December 2015 with a clinical diagnosis of irreversible pulpitis or necrosis in the first or second maxillary and mandibular molars
2. Pulpal status that has been confirmed by a cold test
Target number of participants
Participant exclusion criteria
1. Taking any medication that could alter their perception of pain (analgesic or non steroidal anti-inflammatory drugs)
2. Radiographic findings that included absence of periapical radiolucency except for a widened periodontal ligament
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Campinas State University
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
We intend to publish it at International Endodontic Journal, as soon as we have it registered in ISRCTN.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)