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NCT Number: NCT07831720

Er:YAG Laser for Dental Cavity Preparation

The goal of this clinical trial is to compare Er:YAG laser cavity preparation with conventional rotary instruments in adults who have permanent premolars planned for extraction as part of orthodontic treatment.

The main questions the study aims to answer are:

How do Er:YAG laser and conventional rotary instruments compare in the time needed for cavity preparation? Do participants experience different levels of pain with the two methods? Which cavity preparation method do participants prefer after experiencing both methods? Are there differences in cavity surface and interface characteristics and microleakage between teeth prepared with the two methods?

Researchers will compare Er:YAG laser cavity preparation with conventional rotary cavity preparation using a split-mouth design. Each participant will receive both treatment methods on two different eligible permanent premolars.

Participants will:

Have one eligible premolar prepared with an Er:YAG laser and another eligible premolar prepared with conventional rotary instruments.

Have the two procedures performed at separate visits on different days. Rate their pain after each procedure and indicate which treatment method they would prefer for future dental treatment.

Have the study teeth extracted approximately 1 month later, as already planned for their orthodontic treatment.

After extraction, the teeth will be examined in the laboratory to compare cavity surface and interface characteristics and microleakage between the two preparation methods.

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Key information

Conditions

Dental Caries Behavior Health Behavior Patient Preference Patient Satisfaction Stomatognathic Diseases Tooth Demineralization Tooth Diseases Treatment Adherence and Compliance

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Ho Chi Minh City Odonto-Stomatology Hospital

Ho Chi Minh City, 71011, Vietnam

Location contact

Van TT Nguyen, MSc

CONTACT

[email protected]

+84 918883700

Van TT Nguyen, MSc

PRINCIPAL_INVESTIGATOR

About this study

This is an interventional, split-mouth study designed to evaluate the safety and effectiveness of Er:YAG laser cavity preparation compared with conventional rotary instrumentation.

Adult participants undergoing orthodontic treatment who have permanent premolars scheduled for extraction will be enrolled. Two eligible permanent premolars from each participant will be included. A Class I cavity will be prepared using an Er:YAG laser in one tooth and conventional rotary instruments in the other tooth. Both procedures will be performed by the same dentist at separate visits on different days.

Clinical assessments will include the time required for cavity preparation, pain experienced immediately after each procedure, changes in pulse rate during treatment, and the participant's preferred treatment method after experiencing both techniques.

Following cavity preparation, the teeth will be restored with composite resin. Approximately one month later, the study teeth will be extracted according to the participant's pre-existing orthodontic treatment plan. The extracted teeth will then undergo ex vivo laboratory evaluation.

Selected specimens will be examined using scanning electron microscopy to assess cavity and tooth-restoration interface characteristics. Laboratory evaluation will also assess microleakage between the two cavity preparation methods.

The study will compare the clinical acceptability and ex vivo characteristics of Er:YAG laser cavity preparation with those of conventional rotary cavity preparation.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult participants with permanent maxillary or mandibular premolars scheduled for extraction for orthodontic reasons.
  • Eligible premolars are intact or have carious lesions limited to the enamel and are free of pain symptoms.
  • Where carious lesions are present, teeth meet the study eligibility criteria based on ICDAS II 2009, as specified in the study protocol.
  • Participants voluntarily agree to participate and provide informed consent.
  • No spontaneous or continuous dental pain.
  • Clinical examination, thermal pulp testing, and electric pulp testing are consistent with normal pulp status.
  • Radiographic examination shows no periapical radiolucency and complete root apex formation.
  • Participants have no systemic health condition that could adversely affect healing.

Exclusion criteria

  • Participants with psychological or behavioral conditions that prevent adequate cooperation with the study procedures.
  • Teeth showing radiographic evidence of internal root resorption or pulp canal calcification.

Treatment and study plan

Er:YAG laser

Procedure

Class I cavity preparation will be performed using an Er:YAG laser with a non-contact handpiece in QSP mode for hard-tissue cavity preparation. Residual carious tissue will be checked with a caries detector and additional preparation performed if needed. The cavity will then be restored with composite resin according to the study protocol.

Conventional Rotary Cavity Preparation

Procedure

Class I cavity preparation will be performed using conventional rotary instrumentation with a water-cooled diamond bur. Residual carious tissue will be checked with a caries detector and additional preparation performed if needed. The cavity will then be restored with composite resin according to the study protocol.

Primary outcomes

  1. Pain Intensity During Cavity Preparation

    Time frame: Immediately after each cavity preparation procedure at each of the two treatment visits

    Participant-reported pain intensity will be assessed immediately after each cavity preparation procedure using the Wong-Baker pain scale, ranging from 0 to 10, with higher scores indicating greater pain. Pain scores after Er:YAG laser cavity preparation and conventional rotary cavity preparation will be compared within participants.

Secondary outcomes

  1. Treatment Procedure Time

    Time frame: Periprocedural, from the start to the completion of cavity preparation at each of the two treatment visits.

    The duration of the treatment procedure using each cavity preparation method will be recorded in seconds using a stopwatch. Procedure times for Er:YAG laser and conventional rotary instrumentation will be compared within participants.

  2. Heart Rate During Cavity Preparation

    Time frame: Immediately before and during each cavity preparation procedure

    Heart rate will be measured using a finger pulse monitoring device before and during each cavity preparation procedure and recorded in beats per minute. Heart rate measurements associated with Er:YAG laser and conventional rotary cavity preparation will be compared.

  3. Participant Treatment Preference

    Time frame: Immediately after the second treatment visit, approximately 1 week after the first treatment visit.

    After experiencing both cavity preparation methods, participants will indicate whether they prefer Er:YAG laser cavity preparation or conventional rotary cavity preparation for future dental treatment.

  4. Presence of Cavity Surface Burning on SEM

    Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction

    Presence or absence of surface burning will be assessed on extracted study teeth using scanning electron microscopy (SEM) and compared between Er:YAG laser-prepared and conventional rotary-prepared cavities.

  5. Presence of Cavity Surface Carbonization on SEM

    Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction

    Presence or absence of carbonization will be assessed using scanning electron microscopy on extracted study teeth and compared between the two cavity preparation methods.

  6. Presence of Cavity Margin Cracks on SEM

    Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction

    Presence or absence of cracks at the cavity margins will be assessed using scanning electron microscopy and compared between Er:YAG laser and conventional rotary cavity preparation.

  7. Hybrid Layer Thickness

    Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction

    Hybrid layer thickness will be measured in micrometers using scanning electron microscopy on extracted study teeth and compared between the two cavity preparation methods.

  8. Adhesive Layer Thickness

    Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction

    Adhesive layer thickness will be measured in micrometers using scanning electron microscopy on extracted study teeth and compared between the two cavity preparation methods.

  9. Partially Demineralized Dentin Zone Thickness

    Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction

    The thickness of the partially demineralized dentin zone will be measured in micrometers using scanning electron microscopy and compared between Er:YAG laser and conventional rotary cavity preparation.

  10. Microleakage Dye Penetration

    Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction

    Microleakage will be quantified as dye penetration depth in micrometers. Extracted teeth will be examined under polarized light microscopy at 40× magnification, and dye penetration will be measured using NIS-Elements software.

Study contacts

Contact information is provided by the study sponsor or research team.

Van TT Nguyen, MSc

CONTACT

[email protected]

+84 918883700

Sponsors and collaborators

Lead sponsor

Ho Chi Minh City Odonto-Stomatology Hospital

Other Gov

Collaborators

  • University of Medicine and Pharmacy at Ho Chi Minh City

Registry information

Official study title

Safety and Effectiveness of Er:YAG Laser in Cavity Preparation

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Sep 21, 2026
Registry last updated
Sep 21, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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