Related Experiment Video
Updated: Jun 2, 2026
09:44
Oral Biofilm Analysis of Palatal Expanders by Fluorescence In-Situ Hybridization and Confocal Laser Scanning Microscopy
Published on: October 20, 2011
Bacterial diversity in persistent periapical lesions on root-filled teeth.
Trude Handal1, Dominique A Caugant, Ingar Olsen
1Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Journal of Oral Microbiology
|April 28, 2011
Summary
Persistent apical lesions in root-filled teeth harbor diverse bacteria, including uncultivated species. This bacterial presence may hinder healing and contribute to periapical infections.
Area of Science:
- Microbiology
- Endodontics
- Molecular Biology
Background:
- Persistent apical lesions are common in root-filled teeth.
- Understanding the microbial etiology is crucial for treatment success.
Purpose of the Study:
- To analyze bacterial diversity in persistent apical lesions.
- To utilize culture-independent molecular methods for comprehensive analysis.
Main Methods:
- PCR amplification of the 16s ribosomal RNA gene from lesion DNA.
- Cloning and sequencing of amplified bacterial DNA.
- Analysis of 20 surgically removed apical lesions.
Main Results:
- Bacterial DNA detected in 85% of samples (17/20).
- Identified 75 bacterial taxa across 7 phyla.
- 36% of identified species were previously unculturable, including Fusobacterium, Prevotella, and Tannerella forsythia.
Conclusions:
- A broad spectrum of bacteria exists in therapy-resistant periapical lesions.
- These microorganisms may play a role in the infection's persistence.
- Bacterial presence could impede the healing of periapical lesions.
Related Concept Videos
01:27The Oral Microbiota
The oral microbiome includes a complex ecosystem comprising over 700 microbial species, identified through genomic sequencing and culture-based analyses to date. This community includes a core microbiome, found universally among individuals, and a variable component influenced by environmental factors such as diet, lifestyle, and host genetics. Site-specific conditions, including oxygen gradients, pH levels, and nutrient availability, determine the spatial distribution of these microorganisms...
01:29Microbiota of the Respiratory Tract
The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...
01:28Development of the Oral Microbiota
The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
01:30Bacterial Phylum Actinobacteria
Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
01:27The Skin Microbiota
The human skin serves as a complex ecosystem inhabited by a diverse community of microorganisms, including bacteria, fungi, and viruses. This microbiome plays a critical role in maintaining skin health and defending against pathogenic invaders. The composition of microbial communities varies significantly across different regions of the body, influenced primarily by the local levels of moisture and sebum.Regional Variation in Skin MicrobiotaCutibacterium acnes predominantly colonizes sebaceous...
01:30Bacterial Phylum Spirochaetes
Spirochetes, unique bacteria in the phylum Spirochaetes, are gram-negative, motile, tightly coiled, slender, and flexible. They inhabit aquatic sediments and animals, with some causing diseases like syphilis. Spirochetes are classified into eight genera based on habitat, pathogenicity, phylogeny, and characteristics.Their distinctive motility arises from endoflagella, located within the cell’s periplasm. These endoflagella anchor at the cell poles and extend along the cell length, encased by a...