Determination of a Representative and 3D-Printable Root Canal Geometry for Endodontic Investigations and Pre-Clinical Endodontic Training-An Ex Vivo Study.

Models of artificial root canals are used in several fields of endodontic investigations and pre-clinical endodontic training. They allow the physical testing of dental treatments, the operating of instruments used and the interaction between these instruments and the tissues. Currently, a large number of different artificial root canal models exist whose geometry is created either on the basis of selected natural root canal systems or to represent individual geometrical properties.

Efficacy of Endodontic Disinfection Protocols in an Biofilm Model-Using DAPI Staining and SEM.

The aim of this study was to investigate the antimicrobial efficacy of different disinfection protocols in a novel biofilm model based on a visualization method and to evaluate the potential alteration of dentinal surface. A total of 120 extracted human premolars were allocated to 6 groups with different irrigation protocols. The assessment of the effectiveness of each protocol and the alteration of dentinal surface were visualized by using SEM and fluorescence microscopy (DAPI).

Material Selection Process for Acoustic and Vibration Applications Using the Example of a Plate Resonator.

In this work, a new method for selecting suitable materials is presented. This method has a high potential for a variety of engineering applications, such as the design of sound-absorbing and vibration-loaded structures, where a large number of different requirements have to be met. The method is based on the derivation of functional dependencies of selected material parameters.

Analysis of a Film Forming Process through Coupled Image Correlation and Infrared Thermography.

The aim of the present investigation was to determine the dependence of the material and process parameters of the bending process of thermoplastic films. In this context, parameter combinations leading to high resulting forming ratios were identified. To measure the relevant parameters within the hot bending process, a coupled evaluation of infrared thermography (IRT) and deformation measurement using digital image correlation (DIC) was performed.

Quantification of Bacterial DNA from Infected Human Root Canals Using qPCR and DAPI after Disinfection with Established and Novel Irrigation Protocols.

The removal of bacterial infections within the root canal system is still a challenge. Therefore, the cleansing effect of established and new irrigation-protocols (IP) containing silver diamine fluoride (SDF) 3.8% on the whole root canal system was analyzed using quantitative PCR (qPCR) and 4',6-diamidino-phenylindole-(DAPI)-staining.

An Automated Measurement Method for the Endodontic Working Width of Lower Molars by Means of Parametric Models Using Cone-beam Computed Tomographcy and Micro-Computed Tomography.

Introduction: A new method for the approximation of the root canal's cross-sectional shape and its working width using cone-beam computed tomographic (CBCT) or micro-computed tomographic (micro-CT) imaging was introduced.

Methods: Scanned data from 29 extracted human mandibular first and second molar distal root canals without instrumentation were reconstructed and analyzed with a self-developed measurement algorithm. The 3-dimensional volume models were sliced perpendicular to the vertical axis.

Mapping of the Micro-Mechanical Properties of Human Root Dentin by Means of Microindentation.

The extensive knowledge of root dentin's mechanical properties is necessary for the prediction of microstructural alterations and the teeth's deformations as well as their fracture behavior. Standardized microindentation tests were applied to apical, medial, and cervical root sections of a mandibular human first molar to determine the spatial distribution of the hard tissue's properties (indentation modulus, indentation hardness, Martens hardness, indentation creep). Using an indentation mapping approach, the inhomogeneity of mechanical properties in longitudinal as well as in transversal directions were measured.

Quantification of Bacterial Colonization in Dental Hard Tissues Using Optimized Molecular Biological Methods.

Bacterial infections of root canals and the surrounding dental hard tissue are still a challenge due to biofilm formation as well as the complex root canal anatomy. However, current methods for analyzing biofilm formation, bacterial colonization of root canals and dental hard tissue [e.g.

Sound Transmission Loss of a Sandwich Plate with Adjustable Core Layer Thickness.

Compressible Constrained Layer Damping (CCLD) is a novel, semi-active, lightweight-compatible solution for vibration mitigation based on the well-known constrained layer damping principle. The sandwich-like CCLD set-up consists of a base structure, a constraining plate, and a compressible open-cell foam core in between, enabling the adjustment of the structure's vibration behaviour by changing the core compression using different actuation pressures. The aim of the contribution is to show to what degree, and in which frequency range the acoustic behaviour can be tuned using CCLD.

Continuous Measurement of Three-Dimensional Root Canal Curvature Using Cone-Beam Computed and Micro-Computed Tomography: A Comparative Study.

The knowledge of root canal curvature is crucial regarding the prevention of ledge formation, root perforation and the possibility of endodontic instruments' fracture during endodontic treatments. Therefore, a quantification method of the root canal curvature as well as the applicability of diagnostically relevant tomographic three-dimensional (3D) imaging data is necessary. Hereby, cone-beam computed tomography (CBCT) images and micro-computed tomography (µCT) data of distal root canals were analysed concerning the continuous three-dimensional curvature of human mandibular molars ( n = 50).

Development of a Function-Integrative Sleeve for Medical Applications.

Function-integrative textiles bear the potential for a variety of applications in the medical field. Recent clinical investigations suggest that the application of a function-integrative fabric could have a positive impact on currently applied diagnostic procedures of a specific type of tumour. In this context, the fabric should enable local warming of a patient's upper extremity as well as blood flow measurement.

Is it really penetration? Part 2. Locomotion of Enterococcus faecalis cells within dentinal tubules of bovine teeth.

Objective: The aim of the present vitro study was to examine the question whether devitalized Enterococcus faecalis (E. faecalis) cells can migrate into dentinal tubules and if that process takes place in a time-dependent manner.

Design: Sixty bovine root canals were incubated with devitalized and vital streptomycin-resistant E.

Effects of Endodontic Irrigants on Material and Surface Properties of Biocompatible Thermoplastics.

Passive irrigation is an efficient method for a successful endodontic treatment. During sonic activation biocompatible polymer tips are used to activate irrigants. Compared to ultrasonic activation with metallic tips, polymer tips have the advantage of a reduced risk of fracture and minimise dentine damage.

Design and Testing of a Co-Rotating Vibration Excitation System.

A vibration excitation system (VES) in a form of an active coupling is proposed, designed and manufactured. The system is equipped with a set of piezoelectric stack actuators uniformly distributed around the rotor axis and positioned parallel to each other. The actuator arrangement allows an axial displacement of the coupling halves as well as their rotation about any transverse axis.

Is it really penetration? Locomotion of devitalized Enterococcus faecalis cells within dentinal tubules of bovine teeth.

Objective: The aim of the present study was to evaluate the penetration characteristics of devitalized and vital E. faecalis cells into root dentinal tubules.

Design: Thirteen root canals were incubated with devitalized (4days, 7days, 14days, 28days) and vital (28days) E.

An Approach for a Mathematical Description of Human Root Canals by Means of Elementary Parameters.

Introduction: Root canal geometry is an important factor for instrumentation and preparation of the canals. Curvature, length, shape, and ramifications need to be evaluated in advance to enhance the success of the treatment. Therefore, the present study aimed to design and realize a method for analyzing the geometric characteristics of human root canals.