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Completed

NCT Number: NCT07493278

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

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.

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Key information

Age range

8 year–15 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Medical University of Sofia, Faculty of Dental Medicine

Sofia, 1431, Bulgaria

About this study

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.

Who can participate

Healthy volunteers accepted: No

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

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

Treatment and study plan

Mechanical Caries Removal

Procedure

Participants received conventional mechanical caries removal according to standard pediatric dentistry protocols. Laboratory personnel analyzing PCR results were blinded to group assignments.

Er,Cr:YSGG Laser Caries Removal

Procedure

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

Primary outcomes

  1. 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.

  2. 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.

Sponsors and collaborators

Lead sponsor

Medical University of Sofia

Other

Collaborators

  • European Union

Registry information

Official study title

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)

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Mar 25, 2026
Registry last updated
Mar 30, 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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