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

Completed

Conditions

Intervention / Treatment

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

Interventional

Enrollment (Actual)

32

Phase

  • 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

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
Intervention / Treatment
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

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

Medical University of Sofia

Collaborators

European Union Next Generation

Investigators

  • 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)

October 23, 2025

Primary Completion (Actual)

February 4, 2026

Study Completion (Actual)

February 4, 2026

Study Registration Dates

First Submitted

March 19, 2026

First Submitted That Met QC Criteria

March 19, 2026

First Posted (Actual)

March 25, 2026

Study Record Updates

Last Update Posted (Actual)

March 30, 2026

Last Update Submitted That Met QC Criteria

March 24, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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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