An interventional study of Engine driven files utilized in reciprocation motion and engine driven rotary files utilized in continuous rotation motion in Necrotic Pulps With no Apical Periodontitis, sponsored by Cairo University. Not yet recruiting at 1 site in Egypt. Open to participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Cairo University · Not applicable, Interventional, and Treatment
he main objective of this study is to compare the impact of two different file motions-continuous rotation versus reciprocation-using the same endodontic file system (MG3 Blue rotary files) on postoperative pain and the amount of remaining bacteria inside the root canal in single-rooted teeth with necrotic pulps.
Extrusion of infected debris and persistent intracanal bacteria during root canal treatment can lead to postoperative pain and treatment complications. While various instrumentation systems have been evaluated, differences in file metallurgy, design, and number of files often obscure whether the observed outcomes are due to the movement (kinematics) or the file itself. This study aims to isolate the effect of motion kinematics by using identical rotary files in two distinct movement modes.
Participants will be randomly assigned to one of two groups:
Intervention Group (Reciprocation Motion): Canals will be prepared using MG3 Blue files operated in reciprocation motion.
Comparator Group (Continuous Rotation Motion): Canals will be prepared using MG3 Blue files operated in continuous rotation motion.
All procedures will be performed on single-rooted mandibular premolars diagnosed with pulp necrosis without apical periodontitis. Microbial samples will be collected before and after canal instrumentation to measure the reduction of cultivable bacteria (in colony-forming units, CFU/mL). Postoperative pain levels will be recorded by participants using a Visual Analogue Scale (VAS) at baseline, 24 hours, 48 hours, 72 hours, and 7 days after the first appointment.
The primary outcome of the study is post-instrumentation pain at 72 hours. Secondary outcomes include post-instrumentation pain at 7 days and the amount of remaining intracanal cultivable bacteria following canal preparation.
Background and RationaleA fundamental aim of root canal therapy is controlling pain and resolving apical periodontitis by thoroughly disinfecting the root canal system. Residual bacteria-particularly virulent species like Enterococcus faecalis-and their byproducts inside dentinal tubules are the leading cause of post-treatment complications and endodontic failure. During instrumentation, extruded infected debris can injure periapical tissues, triggering an inflammatory immune response and leading to postoperative pain and flare-ups. While previous research has evaluated how reciprocating versus continuous rotary systems affect postoperative pain and remaining bacteria, most studies used different file designs, cross-sections, or numbers of files, making it difficult to determine whether outcomes were driven by kinematics or file characteristics. This randomized clinical trial isolates the effect of motion kinematics by using identical MG3 Blue rotary files under two different motion dynamics. Study ObjectivesTo compare the effect of different kinematics (continuous rotation versus reciprocation) using MG3 Blue rotary files on:The intensity of postoperative pain. The amount of remaining intracanal cultivable bacteria. Trial DesignType: Parallel, single-center, randomized controlled trial (superiority framework). Allocation Ratio: 1:1. Setting: Post-graduate outpatient clinic of the Endodontics Department, Faculty of Dentistry, Cairo University, Egypt. Participants and Eligibility CriteriaInclusion Criteria:Patients aged between 18 and 50 years (males and females). Systemically healthy (ASA I or II) with no history of anti-inflammatory or antibiotic medications in the past month. Mandibular premolars presenting with a single canal and non-vital pulps (negative response to ethyl chloride cold test, absence of spontaneous pain, and no apical periodontitis). Patients capable of understanding the pain scale and signing the informed consent. Exclusion Criteria:Medically compromised patients (ASA III or IV), pregnant females, or teeth with swelling, fistulous tracts, acute/chronic periapical abscesses, grade II/III mobility, previous root canal therapy, non-restorable structure, or open/immature apices. Intervention Procedures \& Protocol StepsPreoperative Evaluation: Medical/dental history collection and baseline pain assessment using a Modified Visual Analogue Scale (VAS). Local Anesthesia \& Disinfection: Local anesthesia administration followed by disinfection of the oral cavity using 0.2% chlorhexidine gluconate mouthwash and rubber dam isolation. Access Cavity \& Working Length: Access cavity preparation, followed by patency confirmation using stainless steel K-files (#10 and #15). Working length is determined via an electronic apex locator and verified radiographically to be 1 mm shorter than the radiographic apex. Pre-instrumentation Sampling (S1): Initial intracanal microbiological samples are collected using sterile paper points retained for 60 seconds (placed in LAL water for endotoxin assay and VMGA III transport medium for microbial cultivation). Randomized Mechanical Preparation: Patients are allocated via computer-generated randomization to one of two groups: Intervention Group (Reciprocation Motion): Canals are prepared using MG3 Blue rotary files in reciprocation motion (#20/0.10, #15/0.03, #20/0.04, #25/0.04, #30/0.04, and #35/0.04 at 300 RPM and 2 Ncm torque). Comparator Group (Continuous Rotation Motion): Canals are prepared using the same MG3 Blue rotary files in continuous rotation motion following manufacturer instructions (same sizes, 300 RPM, and 2 Ncm torque). Irrigation Protocol: Canals are thoroughly irrigated between file sizes using 3 mL of 2.25% sodium hypochlorite via a 27-gauge side-vented needle, finalized with a saline wash. Post-instrumentation Sampling (S2): Second microbial sample collected identically to S1. Canals are dried, temporarily sealed, and patients are scheduled for a 7-day follow-up appointment for root canal obturation via warm vertical compaction. Outcomes and AssessmentPrimary Outcome: Post-instrumentation pain measured at 72 hours post-procedure using the Visual Analogue Scale (VAS ranging from 0 to 10). Secondary Outcomes:Post-instrumentation pain measured at 7 days post-procedure. Amount of remaining intracanal cultivable bacteria measured via microbiological culture techniques in colony-forming units (CFU/mL) pre- and post-instrumentation.
280 studies on the registry are indexed under Periapical Periodontitis; 79 are open to participants now.
This study's planned enrollment of 42 is below the median of 60 across 245 interventional studies indexed under Periapical Periodontitis.
Browse Periapical Periodontitis studies →Cairo University is the lead sponsor of 4,941 studies on the registry; 1,458 are open to participants now.
Of its 37 completed or terminated interventional studies of FDA-regulated products, 5 (14%) have results posted.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
MG3 Blue rotary file utilized in reciprocation motion
Device: Engine driven files utilized in reciprocation motion
MG3 blue rotary file utilized in continuous rotation motion
Device: engine driven rotary files utilized in continuous rotation motion
MG3 blue rotary files utilized in reciprocation motion
MG3 Blue rotary files utilized in continuous rotation motion
post operative pain
Visual Analogue Scale
Time frame: 72 hours post instrumentation, 7 days post instrumentation
Intracanal bacterial reduction
Microbiological Culture Technique. Sample 1 will be collected from canals after access cavity preparation and Sample 2 will be collected right after mechanical preparation of the canals.
Time frame: Sample 1 before instrumentation, Sample 2 immediately after instrumentation
Plan to share: Undecided
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