An interventional study of Er:YAG Laser and Conventional Rotary Cavity Preparation in Dental Caries, sponsored by Ho Chi Minh City Odonto-Stomatology Hospital. Not yet recruiting at 1 site in Vietnam. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-21.
Sponsored by Ho Chi Minh City Odonto-Stomatology Hospital · Not applicable, Interventional, and Treatment
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.
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.
Exclusion Criteria:
One eligible permanent premolar from each participant will undergo Class I cavity preparation using an Er:YAG laser. Each participant will also receive conventional rotary cavity preparation on another eligible permanent premolar as part of the split-mouth design.
Procedure: Er:YAG Laser
Another eligible permanent premolar from each participant will undergo Class I cavity preparation using conventional rotary instrumentation. Each participant will also receive Er:YAG laser cavity preparation on another eligible permanent premolar as part of the split-mouth design.
Procedure: Conventional Rotary Cavity Preparation
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.
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.
Pain Intensity During Cavity Preparation
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.
Time frame: Immediately after each cavity preparation procedure at each of the two treatment visits
Treatment Procedure Time
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.
Time frame: Periprocedural, from the start to the completion of cavity preparation at each of the two treatment visits.
Heart Rate During Cavity Preparation
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.
Time frame: Immediately before and during each cavity preparation procedure
Participant Treatment Preference
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.
Time frame: Immediately after the second treatment visit, approximately 1 week after the first treatment visit.
Presence of Cavity Surface Burning on SEM
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.
Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction
Presence of Cavity Surface Carbonization on SEM
Presence or absence of carbonization will be assessed using scanning electron microscopy on extracted study teeth and compared between the two cavity preparation methods.
Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction
Presence of Cavity Margin Cracks on SEM
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.
Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction
Hybrid Layer Thickness
Hybrid layer thickness will be measured in micrometers using scanning electron microscopy on extracted study teeth and compared between the two cavity preparation methods.
Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction
Adhesive Layer Thickness
Adhesive layer thickness will be measured in micrometers using scanning electron microscopy on extracted study teeth and compared between the two cavity preparation methods.
Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction
Partially Demineralized Dentin Zone Thickness
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.
Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction
Microleakage Dye Penetration
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.
Time frame: Approximately 1 month after cavity preparation, following orthodontically indicated tooth extraction
Plan to share: No — Individual participant data will not be shared. Participant information will be coded to protect confidentiality, and study results will be reported without identifying individual participants.
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