Chloramphenicol, Tetracycline, Zinc Oxide and Eugenol Paste (CTZ Paste) for Emergency Dental Treatment in Public Health Settings: A Randomized Trial (CTZ- emergency)

May 7, 2026 updated by: Isabelle Elise Squillace Mendes, University of Sao Paulo

Clinical and Radiographic Efficacy of Chloramphenicol, Tetracycline, Zinc Oxide and Eugenol Paste (CTZ Paste) in the Context of Emergency Dental Treatments in Brazilian Public Health: Randomized Clinical Trial

The treatment of pulpal diseases in primary teeth represents a significant challenge in public health, particularly in emergency dental care settings, where factors such as limited clinical time, low child cooperation, and structural constraints directly impact treatment effectiveness. In these contexts, conventional pulpectomy using zinc oxide-eugenol (ZOE), although effective, may present operational limitations that restrict its large-scale applicability in public health systems.

In this scenario, non-instrumental endodontic treatment (NIET), based on the concept of Lesion Sterilization and Tissue Repair (LSTR), has emerged as a simplified alternative. Among the available options, CTZ paste shows potential for single-visit application, reducing clinical time and technical complexity.

This study aims to evaluate the clinical and radiographic non-inferiority of CTZ paste compared to conventional pulpectomy with ZOE in primary molars with pulp necrosis, with or without abscess or fistula, treated in emergency dental care settings.

This is a randomized, pragmatic, controlled, non-inferiority clinical trial conducted at a single center, with clinical and radiographic follow-up at 3, 6, and 12 months. Participants will be allocated into two groups: (1) NIET with CTZ paste and (2) conventional pulpectomy with ZOE.

Primary outcomes include pain resolution and absence of clinical signs of infection. Secondary outcomes include radiographic success, clinical time, child behavior (Frankl Scale), need for retreatment, and oral health-related quality of life.

The findings are expected to provide robust evidence regarding the effectiveness of CTZ paste under real-world clinical conditions, contributing to the development of more accessible and effective protocols within public health systems, with the potential to expand access to conservative treatment and reduce early tooth extractions in pediatric dentistry.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Pulpal diseases in primary teeth remain a significant challenge in public health, particularly in emergency dental care settings. These environments are often characterized by limited clinical time, reduced child cooperation, and structural constraints, all of which may compromise the effectiveness and feasibility of conventional treatments. Pulpectomy using zinc oxide-eugenol (ZOE) is widely recognized as an effective treatment for necrotic primary teeth; however, its technical complexity and time requirements may limit its applicability in high-demand public healthcare systems.

In this context, non-instrumental endodontic treatment (NIET), based on the concept of Lesion Sterilization and Tissue Repair (LSTR), has been proposed as a simplified and less time-consuming alternative. This approach aims to disinfect the root canal system using antimicrobial pastes without mechanical instrumentation. Among these, CTZ paste has shown promising results due to its antimicrobial properties, ease of use, and potential for single-visit treatment, making it particularly suitable for emergency care scenarios.

The present study is designed to evaluate whether CTZ paste is non-inferior to conventional pulpectomy with ZOE in the treatment of primary molars diagnosed with pulp necrosis, with or without the presence of abscess or fistula, in emergency dental care settings.

This is a randomized, controlled, pragmatic, non-inferiority clinical trial conducted at a single center. Eligible participants will be children presenting with necrotic primary molars requiring urgent dental treatment. After enrollment, participants will be randomly allocated into two groups: (1) non-instrumental endodontic treatment using CTZ paste and (2) conventional pulpectomy using ZOE.

All procedures will be performed according to standardized clinical protocols. Clinical and radiographic evaluations will be conducted at baseline and at follow-up intervals of 3, 6, and 12 months. Blinded outcome assessment will be performed whenever feasible to minimize bias.

The primary outcomes of this study are pain resolution and the absence of clinical signs of infection, such as swelling, fistula, or pathological mobility. Secondary outcomes include radiographic success (e.g., absence or reduction of periapical/furcal radiolucency), total clinical time required for the procedure, child behavior during treatment assessed using the Frankl Behavior Rating Scale, need for retreatment, and oral health-related quality of life.

This trial adopts a pragmatic design to reflect real-world clinical conditions, thereby enhancing the external validity and applicability of the findings. The results are expected to provide high-quality evidence regarding the effectiveness and feasibility of CTZ paste in public health settings. If non-inferiority is demonstrated, this approach may support the implementation of simplified, cost-effective, and scalable treatment protocols, contributing to improved access to conservative dental care and reducing the need for early extractions in pediatric populations.

Study Type

Interventional

Enrollment (Estimated)

110

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Pediatric patients presenting with:
  • Irreversible pulpitis in primary molars;
  • Pulp necrosis, with or without abscess, in primary molars.
  • Primary molars with sufficient remaining tooth structure to allow endodontic treatment.
  • Primary teeth in which the permanent successor tooth germ presents developmental stages compatible with Nolla stages 1 to 7, defined as:

Stage 1: Presence of bony crypt with no evidence of calcification; Stage 2: Initial calcification, with appearance of radiopaque points in the crown region; Stage 3: Approximately one-third of crown formation; Stage 4: Approximately two-thirds of crown formation; Stage 5: Crown almost complete, without full calcification; Stage 6: Crown completely formed, without initiation of root formation; Stage 7: Initial root formation.

  • Clinical and radiographic conditions indicating feasibility of tooth maintenance through endodontic treatment, including:
  • Permanent successor in developmental stages prior to Nolla Stage 8;
  • Preservation of the bony crypt.

Exclusion Criteria:

  • Pediatric patients presenting with:
  • Reversible pulpitis;
  • Indication for endodontic treatment in permanent teeth.
  • History of allergy or hypersensitivity to any components of the obturation materials (e.g., CTZ paste or zinc oxide-eugenol).
  • Clinical conditions that prevent adequate management in an outpatient setting.
  • Primary teeth in which the permanent successor:
  • Is in advanced developmental stages (Nolla Stage 8 or higher), and/or
  • Presents disruption of the bony crypt, contraindicating endodontic treatment.
  • Teeth presenting internal root resorption that compromises the feasibility of endodontic treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: CTZ Paste (NIET)
Participants will receive non-instrumental endodontic treatment (NIET) using CTZ paste in a single visit for the management of necrotic primary molars in an emergency dental care setting.
Drug: CTZ Paste
CTZ paste is an antimicrobial intracanal medication used in non-instrumental endodontic treatment. The paste is placed into the pulp chamber without mechanical instrumentation, aiming to disinfect the root canal system based on the principles of lesion sterilization and tissue repair (LSTR).
Active Comparator: ZOE Pulpectomy
Conventional pulpectomy involving mechanical instrumentation of root canals, irrigation, and obturation with zinc oxide-eugenol paste.
Procedure: ZOE Pulpectomy
Conventional pulpectomy involving mechanical instrumentation of root canals, irrigation, and obturation with zinc oxide-eugenol paste.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pain Resolution and Clinical Infection Control
Time Frame: Up to 7 days post-treatment (primary endpoint), with follow-up assessments at 3, 6, and 12 months.
Resolution of dental pain and absence of clinical signs of infection following emergency endodontic treatment in primary molars. Pain will be assessed using the Wong-Baker Faces Pain Rating Scale, a validated scale for measuring pain intensity in children. Scores range from 0 to 10, where 0 indicates "no pain" and 10 indicates "worst possible pain." Higher scores indicate greater pain intensity (worse outcome). Infection control will be determined by the absence of clinical signs such as swelling, fistula, abscess, or pathological mobility. The outcome will also consider the need for unplanned additional interventions as an indicator of treatment failure.
Up to 7 days post-treatment (primary endpoint), with follow-up assessments at 3, 6, and 12 months.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Child Behaviour and Oral Health-Realated Quality of Life
Time Frame: Baseline and 3, 6, and 12 months after treatment

The child's behavior and acceptance of the dental procedure during treatment will be assessed. Child behavior will be evaluated using the Frankl Behavior Rating Scale, a validated four-point scale for assessing cooperation, where 1 indicates definitely negative behavior, 2 indicates negative behavior, 3 indicates positive behavior, and 4 indicates definitely positive behavior. Higher scores indicate more positive behavior (better outcome). In addition, clinical observation of cooperation, the need for behavioral management strategies, and overall acceptability of the procedure will be recorded.

The impact of treatment on the child's and caregiver's quality of life will be assessed using validated oral health-related quality of life questionnaires, such as the Early Childhood Oral Health Impact Scale (ECOHIS). ECOHIS total scores range from 0 to 52, where higher scores indicate a greater negative impact on oral health-related quality of life (worse outcome). Subscores for Child Impact
Baseline and 3, 6, and 12 months after treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Sao Paulo

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 8, 2026

Primary Completion (Estimated)

December 20, 2027

Study Completion (Estimated)

February 28, 2028

Study Registration Dates

First Submitted

April 14, 2026

First Submitted That Met QC Criteria

April 14, 2026

First Posted (Actual)

April 21, 2026

Study Record Updates

Last Update Posted (Actual)

May 12, 2026

Last Update Submitted That Met QC Criteria

May 7, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • USaoPaulo

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual Participant Data (IPD) will not be shared. The decision not to share IPD is based on ethical and regulatory considerations, as the study involves pediatric participants and includes potentially sensitive clinical data. Data confidentiality and participant privacy will be strictly maintained in accordance with applicable data protection regulations and institutional ethics committee requirements.

Only aggregated data will be reported in scientific publications and presentations. No individual-level data will be made publicly available.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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