Search results for " Dentin"
showing 10 items of 33 documents
Inflammatory Response Mechanisms of the Dentine–Pulp Complex and the Periapical Tissues
2021
The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The fron…
Induced post-traumatic apexification: 20 year follow-up and morphological study after new fracture.
2018
Apexification is an endodontic technique used in immature necrotic teeth, the primary goal of which is to induce a calcified barrier in roots with open apices and to promote the continuation of apical root development. A 7-year-old patient with a coronal fracture in a maxillary central incisor was treated with an apexification technique using calcium hydroxide. The apical closure was obtained after one year, then a permanent root canal filling was performed. The tooth was monitored for a period of 20 years, up to when a trauma caused its extraction. The newly formed root was analyzed macroscopically, histologically and through scanning electron microscopy. A morphologically normal root was …
Danger zone analysis using cone beam computed tomography after apical enlargement with K3 and K3XF in a manikin model
2015
Background The objective of the study was to evaluate and compare how apical enlargement with K3 and K3XF nickel-titanium (NiTi) rotary instruments reduces the root thickness in the danger zone and affects canal transportation and centering ability in mandibular molar mesial canals in a manikin extracted tooth model. Material and Methods Seventy-two mesial root canals of first mandibular molars were instrumented. Initial and post-instrumentation Cone Beam Computed Tomography scans were performed after root canal preparation up to size 25, 30, 35 and 40 files. Canal transportation, canal centering and remaining root dentin thickness toward the danger zone were calculated in sections 1, 2 and…
Comparative evaluation of bioactive cements on biomimetic remineralization of dentin
2020
Background This study was designed to quantitatively compare the presence of apatite peaks on demineralized dentin to induced bio-mimetically by bioactive commercial materials. Material and methods Dentin slice specimens (n=6) were prepared and demineralized by by17% EDTA for 2 hours. Each disks materials (Theracal, Biodentine, CPP-ACP) were freshly prepared and was maintained in close contact with a demineralized dentin specimen immersed in PBS solution during one week. To evaluation of bioactivity, cements disks (n=6) were prepared from each material and immersed in PBS solution for one week. The bioactivity and remineralization ability was evaluated using FTIR spectroscopy and Scanning E…
Hybrid layers of etch-and-rinse versus self-etching adhesive systems.
2010
Objective: To evaluate the effectiveness in the formation of resin tags, adhesive lateral branches and hybrid layers of five adhesive systems, when bonding to dentine. Material and Methods: Flat dentin surfaces from 25 molars were bonded with several adhesive systems according to the manufacturers? instructions. Composite build-ups were constructed incrementally with Tetric Ceram. The Specimens were sectioned parallel to the long axis. One section was treated with phosphoric acid and sodium hypochlorite in order to reveal the hybrid layer formation. The other section was stored in 30% hydrochloric acid to detect resin tags and adhesive lateral branch formation. Results: The two etch-and-rin…
Occurrence of invading bacteria in radicular dentin of periodontally diseased teeth: Microbiological findings
1997
Bacterial invasion in roots of periodontally diseased teeth, which has been recently documented using cultural and microscopic techniques, may be important in the pathogenesis of periodontal disease. The purpose of this investigation was to determine the occurrence and the species of invading bacteria in radicular dentin of periodontally diseased teeth. Samples were taken from the middle layer of radicular dentin of 26 periodontally diseased teeth. 14 healthy teeth were used as controls. Dentin samples were cultured anaerobically. The chosen methodology allowed the determination of the numbers of bacteria present in both deeper and outer part of dentinal tubules, and the bacterial concentra…
Identification of Lactobacilli from Deep Carious Lesions by Means of Species-Specific PCR and MALDI-TOF Mass Spectrometry
2014
SUMMARY Background: The aim of the present study was to compare MALDI-TOF results for the identification of 87 lactobacilli, isolated from soft or hard carious dentin from 70 first molars of 7- to 8-year-old children with those obtained by species-specific PCR. Methods: The 87 isolates were analyzed by MALDI-TOF MS (Microflex LT, MALDI Biotyper 3.0, Bruker Daltonik, Bremen, Germany), using a reference data base of 4110 strains including > 90 lactobacillus species. For the identification with species-specific PCR, oligonucleotide primers (16S rRNA) specific for L. casei, L. paracasei, L. rhamnosus, L. gasseri, L. plantarum, and L. acidophilus were used; type strains served as controls. The P…
Evaluation of Effects of Various Irrigating Solutions on Chemical Structure of Root Canal Dentin Using FTIR, SEM, and EDS: An In Vitro Study
2022
Background: Sequential chemical application for irrigating a root canal during chemomechanical debridement can affect the dentin microstructure. Understanding the effects of various irrigants on chemical properties of dentin can elucidate their effects on physical properties and thereby explain the higher incidence of structural failure in endodontically treated teeth. This in vitro research aimed to compare and evaluate the effects of three different irrigating solutions on the chemical structure of root canal dentin in extracted human teeth. Methods: Forty-eight extracted single-rooted mandibular premolar teeth were sectioned at the cemento–enamel junction by a diamond disc and were…
Dentist´s knowledge, attitudes and determining factors of the conservative approach in teeth with reversible pulpitis and deep caries lesions
2018
Background The aim of this study was to investigate dentists` knowledge, attitudes and factors regarding the conservative approach in the management of deep caries lesions (DCLs) in teeth with reversible pulpitis. Material and methods 187 dentists were contacted directly or by mail, and 125 (67%) were finally included in the study. Dentists were requested to answer an open/discursive questionnaire about the routine approach to the diagnosis and treatment of DCLs, including knowledge-related attitudinal items. Results Total caries excavation was the preferred treatment option for more than 80% of dentists in case of DCL with reversible pulpitis. Only a small percentage (8%) chose partial car…
La evolución de la adhesión a dentina
2004
-Isabel.Camps@uv.es Se realiza una revisión a la historia de la adhesión comenzando en las culturas precolombinas ("era pre-adhesiva"), para continuar en la "era adhesiva" con las aportaciones de Buonocuore y la aparición del Bis-GMA, pasando por la incorporación al mercado dental de los fosfatos, los oxalatos, el sistema Gluma. Se analiza también la descripción la capa híbrida por Nakabayashi, después aparecen los primers acuosos y la hibridación de tejidos duras hasta llegar a los sistemas adhesivos autograbadores. An overview of dentin bonding history is done by the author since early south American cultures (pre-adhesive age) to continued in the adhesive age with Buonoccore's findings a…