Search results for "in vitro study"
showing 10 items of 99 documents
Microleakage in Class II composite restorations with margins below the CEJ: in vitro evaluation of different restorative techniques.
2012
Objectives: The purpose of this in vitro study was to evaluate the microleakage in "deep" Class II composite restorations with gingival cavosurface margin below the CEJ (cemento-enamel junction) and restored with different techniques. Study Design: Fifty human teeth were used. In each tooth two standardized Class II slot cavities (on mesial and on distal surfaces) were prepared: the buccolingual extension of the cavities was 4 mm; the gingival wall was located in dentin/cementum (2 mm beyond the CEJ). The prepared teeth were randomly assigned to 5 experimental groups (of 10 specimens and 20 cavities each) and restored. Group 1: Filtek TM Supreme XTE Flowable (3MESPE) + Universal Filtek Supr…
In vitro study of the apical microleakage with resilon root canal filling using different final endodontic irrigants
2015
Background: Endodontic microleakage or microfiltration refers to the percolation of fluids and micro-organisms at the interface of the obturation material and the walls of the root canal system. The aim of this in vitro study was to compare apical microfiltration of Resilon root canal filling by employing three dif ferent final irrigant solutions. Material and Methods: 128 single-rooted teeth were employed. The crowns were sectioned horizontally at the cemento-enamel junction and instrumented with 5.25% sodium hypochlorite (NaOCl) and 17% EDTA gel to obtain an instrumented 040 apical caliber. An intermediate irrigation was performed with distilled water. The roots were then randomly assigne…
Influence of energy drinks on enamel erosion : in vitro study using different assessment techniques
2021
Background Dental erosion has become a relevant public health problem in recent years and is related to the increase in the consumption of acidic beverages. Objective: The aim of the present study was to evaluate the erosive potential of energy drinks on dental enamel using an in vitro erosion model. Material and Methods Thirty-eight blocks of human enamel were divided into four groups: G1- TNT Energy Drink®(n=8), G2- Red Bull® (n=10), G3- Monster Energy® (n=10), and G4- Coca-Cola® (n=10) (positive control). For the chemical analysis, the pH values, titratable acidity, and buffering capacity of the beverages were measured in triplicate. For the erosive test, the specimens were immersed in t…
Effect of hemostatic agent on marginal gaps of class V giomer restorations
2017
Background Contamination of dentin with hemostatic agents might exert a deleterious effect on adhesive procedures on dentin. The present study was undertaken to investigate the effect of aluminum chloride hemostatic agent on marginal gaps in Cl V giomer restorations. Material and Methods Fifty sound bovine permanent incisors were selected for the purpose of this in vitro study and Cl V cavities were prepared on their buccal surfaces; the gingival margins of the cavities were placed in dentin. The tooth samples were randomly assigned to two groups (n=25). The samples in groups 1 and 2 underwent a restorative procedure without and with the application of aluminum chloride hemostatic agent in …
Thermoplastic Properties of Endodontic Gutta-percha: A Thermographic In Vitro Study
2014
Abstract Introduction Endodontic gutta-percha undergoes deformation at temperatures above 65°C. The temperature influence of heat carriers on gutta-percha cones was investigated in vitro. Methods Six single-rooted extracted teeth were embedded in resin and fixed. The root canals were prepared (ProFile; Dentsply Maillefer, Ballaiques, Switzerland) to different tapers and bisected. Thermographic images when heating the gutta-percha cones (Roeko, Langenau, Germany) with a heat carrier (ML .12; SybronEndo, Orange, CA) at 1 and 5 mm from the working length were made with an infrared thermal imaging camera (ThermaCam P640; Flir Systems, Taby, Sweden). The device temperature was preset at 200°C. T…
Effect of bone loss on the fracture resistance of narrow dental implants after implantoplasty. An in vitro study
2021
Background Implantoplasty (IP) involves polishing of the exposed surface of implants affected by peri-implantitis (PI). A study was made to determine whether the degree of bone loss influences the fracture resistance of implants with or without IP. Material and Methods An in vitro study was carried out on 32 narrow (3.5 mm) dental implants with a rough surface and external hexagonal connection. Implantoplasty was performed in half of the implants of the sample. Both the IP and control implants were divided into two subgroups according to the amount of bone loss (3 mm or 7.5 mm). Standardized radiographic assessment of implant width was performed using specific software. The main outcome var…
Influence of cortical bone and implant design in the primary stability of dental implants measured by two different devices of resonance frequency an…
2020
Background This study aimed to evaluate the effect of the implant design and the presence of cortical bone in the primary stability, as well as analyze the differences between the stability measurements obtained by two different resonance frequency analysis (RFA) devices. Material and methods A total of 80 Klockner implants of two different models [40 Essential Cone implants (group A) and 40 Vega implants (group B)] were used. The implants were placed in two polyurethane blocks that simulated the mechanical properties of the maxillary bone. One block featured a layer of cortical bone that was absent from the other block. The primary stability of all implants was measured by insertion torque…
A new implant-abutment connection for bacterial microleakage prevention: An in vitro study
2017
Purpose The aim of our study is to evaluate the ability of a new type of implant (Konus Implant System®, Industrie biomediche e farmaceutiche, Italy) to isolate the internal of an implant-abutment connection from the external environment. Materials and methods To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Implants were immerged in a bacterial culture for twenty-four hours and then bacteria amount was measured inside implant-abutment interface with Real-time PCR. Results Bacteria were detected inside all studied implants, with a median…
Concentration-Dependent Protection by Ethanol Extract ofPropolis against γ
2011
[EN] Radioprotection with natural products may be relevant to the mitigation of ionizing radiation-induced damage in mammalian systems; in this sense, propolis extracts have shown effects such as antioxidant, antitumoral, anti-inflammatory, and immunostimulant. We report for the first time a cytogenetic study to evaluate the radioprotective effect, in vitro, of propolis against radiation-induced chromosomal damage. Lymphocytes were cultured with increasing concentrations of ethanol extract of propolis (EEP), including 20, 40, 120, 250, 500, 750, 1000, and 2000 ¿g mL-1 and then exposed to 2 Gy ¿-rays. A significant and concentration-dependent decrease is observed in the frequency of chromoso…
Effect of 15% carbamide peroxide bleaching gel on color stability of giomer and microfilled composite resin: an in vitro comparison
2011
Objectives: The effect of 15% carbamide peroxide bleaching gel on color stability and surface topography of a giomer and a microfilled composite resin was evaluated in the present in vitro study. Study design: Forty discs measuring 10 mm in diameter and 1 mm in thickness were prepared from a giomer and a microfilled composite resin. Each material yielded 20 discs with completely smooth surfaces. Then a spectrophotometer was used to measure L* (lightness), a* (redness, greenness) and b* (blueness, yellowness) color coordinates of all the discs. Subsequently, the specimens were subjected to 15% carbamide peroxide bleaching gel. After measuring the color coordinates once again, color changes (…