In Vivo Pulp Thermal Changes During Different Slenderization Techniques (IPR)

Pulp Temperature Elevation During Interproximal Reduction: An In Vivo Quantification of Temperature Changes Across Different Slenderization Methods

The goal of this study is to learn about the temperature rise inside the living part of a tooth (the pulp) during different ways of removing a small amount of enamel (the hard outer layer of the tooth), a procedure called Interproximal Enamel Reduction (IPR).

The goal of this study is to learn about the temperature rise inside the living part of a tooth (the pulp) during different ways of removing a small amount of enamel (the hard outer layer of the tooth), a procedure called Interproximal Enamel Reduction (IPR).

The main question it aims to answer is:

Which IPR technique causes the highest temperature rise in the live tooth pulp?

This study is important because, until now, no research has measured these temperature changes in the live pulp of teeth inside a person's mouth (in vivo) that includes both premolars and front teeth (incisors). The original studies only used premolars, and the results might be different for front teeth due to the difference in enamel thickness.

Researchers will use 20 premolar teeth and 20 incisors that will be scheduled for extraction as part of orthodontic treatment. The teeth will be divided into two groups based on the IPR method used:

Group 1: IPR using a high-speed air-driven drill (airotor) and bur. Group 2: IPR using an orthodontic IPR kit (an oscillating system).

Participants will:

Receive local anesthesia to numb the tooth. Have the baseline temperature of the pulp recorded using temperature sensor on either side of the teeth.

Have the temperature changes in the pulp recorded using temperature sensor while IPR is performed on the sides of the tooth.

Have the tooth extracted afterward (as part of original orthodontic plan)

The key findings may provide information of the IPR method that cause a temperature rise high enough to harm the pulp. A rise beyond 5.5∘C may cause pulp damage.

Study Overview

• Status: Active, not recruiting
• Conditions: Irreversible Pulpitis; Pulp Necrosis; Thermal Injury; Reversible Pulpitis; Pulp Inflammation; Pulp Hyperemia
• Intervention / Treatment: Device: High-Speed Air-Driven Drill (Airotor and Bur); Device: Orthodontic IPR Kit (Oscillating System)

Detailed Description

Study Objectives The primary goal of this investigation is to evaluate the in vivo (inside the body) temperature rise within the dental pulp (the living tissue inside the tooth) when different techniques of Interproximal Enamel Reduction (IPR) are performed.

The core aims are:

1. To measure and compare the magnitude of pulp temperature increase across two common IPR methods.
2. To determine if any of the evaluated techniques have the potential to raise the pulp temperature above a critical threshold (5.5 degrees C), which is historically associated with irreversible pulp damage.
3. To identify which IPR technique carries the highest possibility of thermal injury.

Rationale and Significance Previous studies that looked at this issue were performed ex vivo (on extracted, non-living teeth). This study is crucial because it measures temperature changes in live, intact teeth under actual clinical conditions, providing a more reliable assessment of risk.

A key difference in this research, compared to other literature, is the inclusion of both incisors (front teeth) and premolars. Since the enamel thickness on incisors is generally less than on premolars, there is a possibility that the heat generated during IPR may transfer more readily to the pulp in the anterior teeth, potentially leading to a greater temperature rise and a higher risk of adverse thermal effects. This study aims to clarify this potential risk.

Study Design and Methods This is a randomized clinical trial, an in vivo study involving participants undergoing orthodontic treatment where tooth extraction is required.

Participant Population The study will involve participants for whom the extraction of specific teeth (premolars and incisors) has been clinically advised as part of their orthodontic treatment plan. These teeth will be used for the IPR procedures just before they are extracted.

Procedure Groups (Interventions)

The teeth will be randomly assigned to one of the following two IPR technique groups, with the potential for each to generate a different amount of frictional heat:

1. High-Speed Air-Driven Drill (Airotor and Bur): This method involves high rotational speed (potentially over 300,000 RPM) and thus has the highest possibility of causing the greatest temperature elevation due to intense friction.
2. Orthodontic IPR Kit (Oscillating System): This technique operates at a much lower speed (around 5,000 RPM) and is expected to result in a moderate temperature increase, presenting a moderate possibility of thermal effect compared to the high-speed drill.

Measurement Prior to the IPR procedure, local anesthesia will be administered. A sensitive thermocouple directly on the surface of tooth to meausre baseline temperature of the pulp.

The chosen IPR procedure will be performed. The temperature changes in the pulp will be monitored at two time points and recorded during the IPR process.

The data gathered will be used to compare the techniques and determine the relative possibility of thermal damage posed by each method, particularly within the incisors, which are uniquely included in this research.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Pakistan
  • Punjab Province
    • Rawalpindi, Punjab Province, Pakistan, 44000
      • Armed Forces Intitute of Denistry (AFID), Combined Military Hospital (CMH)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participants 12 to 25 years of age.
• Participants undergoing orthodontic treatment requiring extraction of the teeth being studied (Incisors or Premolars).
• Selected tooth must be intact (no decay, large fillings, or fractures).
• Tooth must test vital (alive and healthy) prior to the procedure.
• Tooth must have healthy surrounding gum tissue.

Exclusion Criteria:

• Teeth that are non-vital (dead), have root canal treatment, or signs of irreversible pulpitis.
• Teeth with existing large or deep restorations (fillings) or crowns/veneers.
• Teeth that have undergone any previous IPR or stripping procedure.
• Teeth with significant developmental enamel defects (e.g., severe hypoplasia or fluorosis).
• Participants with severe systemic diseases (e.g., uncontrolled diabetes) affecting dental health.
• Participants taking medications that affect pulp sensation or vascular response (e.g., long-term anti-inflammatories).
• Participants who are pregnant or breastfeeding.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Premolar Group; Bilateral premolars planned for extraction as part of orthodontic treatment in a patient will undergo intervention using both the IPR methods to measure the changes in pup temperature. First baseline temperature wil be recorded intraorally then one side premolar (e.g; right) will undergo IPR using Air-rotor system and then the other side premolar (e.g; left) will undergo IPR using oscillating strip	Device: High-Speed Air-Driven Drill (Airotor and Bur); This method involves high rotational speed (potentially over 300,000 RPM) and thus has the highest possibility of causing the greatest temperature elevation due to intense friction during interproximal reduction.; Device: Orthodontic IPR Kit (Oscillating System); This technique operates at a much lower speed (around 5,000 RPM) and is expected to result in a moderate temperature increase, presenting a moderate possibility of thermal effect compared to the high-speed drill during interproximal reduction.
Experimental: Incisor Group; Patients planned for lower single incisor extraction will be divided into two groups and undergo IPR using two different IPR techniques intraorally prior to extraction of the tooth.	Device: High-Speed Air-Driven Drill (Airotor and Bur); This method involves high rotational speed (potentially over 300,000 RPM) and thus has the highest possibility of causing the greatest temperature elevation due to intense friction during interproximal reduction.; Device: Orthodontic IPR Kit (Oscillating System); This technique operates at a much lower speed (around 5,000 RPM) and is expected to result in a moderate temperature increase, presenting a moderate possibility of thermal effect compared to the high-speed drill during interproximal reduction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The highest temperature reached inside the pulp chamber for each tooth during the IPR procedure	The highest temperature reached inside the pulp chamber for each tooth during the IPR procedure will be recorded using temperature sensor keeping it on the mid, mesial and distal facial surfaces of the tooth at different tie points; T0 (prior to IPR procedure), TD (during IPR procedure with the techniques specified) T1 (immediately after IPR), and T2 (after 5 mins post IPR)	From enrollment to the date of planned extraction of the patient's teeth at 8 weeks so that all the measurements can be taken from T0 to T2 [T0 (prior to IPR procedure), TD (during IPR procedure with the techniques specified) T1 (immediately after IPR)]
Mean maximum temperature rise per IPR technique	Description: The calculated average of the maximum temperature rise for all teeth treated with a specific IPR technique. Analysis: This measure will be broken down by IPR technique and by tooth type (incisors vs. premolars). Conclusion: The method that consistently produces the lowest mean temperature rise across all groups is considered the most thermally conservative method.	from enrollment to the point of extraction of patient's teeth at 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Residual Pulp Temperature Difference at 5 Minutes Post-IPR	The remaining temperature difference between the recorded pulp temperature at the 5-minute mark (T2) and the tooth's original baseline temperature (T0). This directly measures the thermal recovery efficiency of the tooth. A difference closer to 0∘ C will indicate faster and more complete recovery, suggesting the IPR technique/tooth type is better able to manage thermal stress.	From enrollment to the date of planned extraction of the patient's teeth at 8 weeks so that all the measurements can be taken from T0 to T2 [T0 (prior to IPR procedure), TD (during IPR procedure with the techniques specified) T1 (immediately after IPR)]

Collaborators and Investigators

• Sponsor: Armed Forces Institute of Dentistry, Pakistan
• Investigators: Principal Investigator: Alaina Tariq Mughal, BDS, FCPS (R), Armed Forces Institute of Dentistry, Pakistan

Publications and helpful links

Helpful Links

• In vivo study measuring pulp ΔT during IPR with high-speed, oscillating, and manual methods on premolars. All methods were deemed thermally safe (ΔT<5.5 ∘C). This justifies extending the safety analysis to incisors.

Study record dates

Study Major Dates

• Study Start (Actual): September 29, 2024
• Primary Completion (Estimated): October 29, 2026
• Study Completion (Estimated): October 29, 2026

Study Registration Dates

• First Submitted: September 30, 2025
• First Submitted That Met QC Criteria: February 2, 2026
• First Posted (Actual): February 5, 2026

Study Record Updates

• Last Update Posted (Actual): February 17, 2026
• Last Update Submitted That Met QC Criteria: February 13, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: irreversible pulpitis; IPR; interproximal reduction; slenderization; thermal pulp damage; premolars; incisors
• Additional Relevant MeSH Terms: Aortic Valve Disease; Stomatognathic Diseases; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Dental Pulp Diseases; Tooth Diseases; Necrosis; Heart Valve Diseases; Congenital Abnormalities; Cardiovascular Abnormalities; Heart Defects, Congenital; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathological Conditions, Signs and Symptoms; Bicuspid Aortic Valve Disease; Dental Pulp Necrosis
• Other Study ID Numbers: 918/Trg

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

IPD Plan Description

Conditions for Sharing:

Request Process: Requests must be made formally to the Principal Investigator (or corresponding author) of the study.

Purpose: Requests must include a detailed research proposal outlining the scientific rationale for using the data.

Anonymization: All shared data will be fully anonymized to protect participant confidentiality and meet the requirements set forth by the institutional ethics review board.

Timing: Data will be made available following the publication of the main study results.

Data Use Agreement: Researchers accessing the data will be required to sign a formal data use agreement to ensure the data is used only for the approved purpose and is not shared further.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No