Er,Cr:YSGG Laser Versus Conventional Preparation for Minimally Invasive Caries Removal

March 24, 2026 updated by: Medical University of Sofia

Er,Cr:YSGG Laser Versus Conventional Preparation for Minimally Invasive Caries Removal: Clinical PCR Study of Streptococcus Mutans and Lactobacillus Spp. in Dentin Reference to the Main Project (Sub-study of Strategic Research and Innovation Program for Development of Medical University - Sofia, BG-RRP-2.004-0004-C01)

This study compared two standard methods for minimally invasive caries removal in children: conventional mechanical excavation and Er,Cr:YSGG laser preparation. The study aimed to evaluate the reduction of Streptococcus mutans and Lactobacillus spp. in dentin using PCR analysis. All procedures were performed as part of routine dental care, and written informed consent was obtained from parents or legal guardians.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This comparative clinical study included 32 carious lesions in permanent molars and premolars from children aged 8-15 years. Lesions were randomly assigned to either conventional mechanical preparation (n=17) or Er,Cr:YSGG laser preparation (n=15). Samples of carious and affected dentin were collected before and after preparation, and bacterial DNA was analyzed using PCR for S. mutans and Lactobacillus spp. The study followed ethical approval from the Ethics Committee of the Medical University of Sofia (protocol № 14/28.09.2023), and written informed consent was obtained from all parents/guardians. The study was conducted entirely within the framework of routine dental treatment, with standard, clinically approved methods applied for all participants. Statistical analysis included descriptive statistics, Wilcoxon signed-rank test for within-group comparisons, and Mann-Whitney U test for between-group comparisons.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
32

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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

Study Locations

  • Bulgaria
    • Sofia
      • Sofia, Sofia, Bulgaria, 1431
        • Medical University of Sofia, Faculty of Dental Medicine

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Lesions located in the inner half of dentin, with a visible cavity or extensive dentin lesion (≥1 mm, measured with a periodontal graded probe)
  • Negative response to percussion
  • Absence of pulpal symptoms or spontaneous/night pain
  • Permanent molars or premolars fully erupted

Exclusion Criteria:

  • Lesions involving less than half of the dentin or without a visible cavity
  • Teeth with significant crown destruction (ICDAS 06)
  • Positive response to percussion, pulpal symptoms, spontaneous/night pain
  • Teeth with periapical changes

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: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Mechanical Preparation
Participants received conventional mechanical caries removal according to standard pediatric dentistry protocols. Laboratory personnel analyzing PCR results were blinded to group assignments.
Procedure: Mechanical Caries Removal
Participants received conventional mechanical caries removal according to standard pediatric dentistry protocols. Laboratory personnel analyzing PCR results were blinded to group assignments.
Experimental: Er,Cr:YSGG Laser Preparation
Participants received caries removal using the Er,Cr:YSGG laser (2780 nm) according to manufacturer-recommended parameters for minimally invasive dentin excavation. Laboratory personnel analyzing PCR results were blinded to group assignments.
Procedure: Er,Cr:YSGG Laser Caries Removal
Participants received caries removal using the Er,Cr:YSGG laser (2780 nm) according to manufacturer-recommended parameters for minimally invasive dentin excavation. Laboratory personnel analyzing PCR results were blinded to group assignments

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in levels of S. mutans and Lactobacillus spp. in dentin samples.
Time Frame: Before and immediately after caries removal
The presence of S. mutans and Lactobacillus spp. in dentin samples will be assessed using PCR. Samples are collected before and after mechanical or Er,Cr:YSGG laser caries removal to determine bacterial reduction for both microorganisms.
Before and immediately after caries removal
Change in levels of S. mutans and Lactobacillus spp. in dentin samples
Time Frame: Before and immediately after caries removal
The presence of S. mutans and Lactobacillus spp. in dentin samples will be assessed using PCR. Samples are collected before and after mechanical or Er,Cr:YSGG laser caries removal to determine bacterial reduction for both microorganisms.
Before and immediately after caries removal

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Medical University of Sofia

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
European Union Next Generation

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Natalia Grancharova, MD, PhD, Medical University Sofia

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.

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 23, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 4, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 4, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 19, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 19, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 25, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 30, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 14/28.09.2023

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared in order to protect patient privacy and comply with ethical approvals and consent restrictions.

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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