Automated Support Generation for Fixed Partial Dentures and Impact of Bone Loss, Bone Quality and Support Types: Parametric Cad and Finite Element Analysis.

This study aimed to develop an algorithm for modelling tooth-tooth or implant-implant support configurations for a given 4-unit fixed partial denture (FPD). : The algorithm was implemented in Rhinoceros/Grasshopper to automatically generate geometries with varying bone loss (0 mm to 3 mm), support type (tooth-tooth and implant-implant support) and bone quality (D1 to D4) for a 4-unit FPD. Afterward, a finite element analysis was carried out with a load applied to the central connector of the FPD.

Automatic adjustment of dental crowns using Laplacian mesh editing.

Currently, the restoration of missing teeth by means of dental implants is a common treatment method in dentistry. Ensuring optimal contact between teeth (occlusion) when designing the occlusal surface of an implant-supported crown is crucial for the patient. Although there are various occlusal concepts and guidelines for achieving optimised occlusion, adapting an occlusal surface is challenging.

The effects of different grading approaches in additively manufactured dental implants on peri-implant bone stress: A finite element analysis.

Additive manufacturing enables local grading of the stiffness of dental implants through targeted adjustment of the manufacturing parameters to meet patient specific requirements. The extent to which such a manufacturing approach affects the interaction between the implant body and the surrounding bone, and what grading is optimal, is currently insufficiently investigated. This study investigates the effect of different Young's modulus grading approaches on stresses in the peri-implant bone via finite element analysis.

Automated Remodelling of Connectors in Fixed Partial Dentures.

In this study, an approach for automated parametric remodelling of the connector cross-sectional area in a CAD model of a given fixed partial denture (FPD) geometry was developed and then applied to a 4-unit FPD. The remodelling algorithm was implemented using Rhinoceros and the Grasshopper plugin. The generated CAD models were used to perform a finite element analysis with Ansys to analyse the stress distribution in an implant-supported 4-unit FPD for different connector designs.

Semi-automated generation of bone loss defects around dental implants and its application in finite element analysis.

This study aimed to develop an algorithm for modelling bone loss defects in a given mandibular geometry, with a user-defined depth, width, place, and defect type. The algorithm was implemented using Grasshopper and models with different bone loss types and depths around a dental implant were built. The models were used in a finite element analysis (FEA) to predict the stresses in peri-implant bone.

Fracture Resistance of Repaired 5Y-PSZ Zirconia Crowns after Endodontic Access.

This study analyzed the fracture load before and after a chewing simulation of zirconia crowns that were trepanned and repaired using composite resin. Overall, 3 groups with 15 5Y-PSZ crowns in each group were tested. For group A, the fracture load of the unmodified crowns was evaluated.

Preventing stress singularities in peri-implant bone - a finite element analysis using a graded bone model.

In finite element analysis bone is often treated as two-layered material that has a discontinuity between the cortical and cancellous bone, which leads to a singularity and incorrect stresses. The goal of this study was to eliminate this singularity and to create a more realistic representation of bone which also considers the transition zone between cortical and cancellous bone as observed in natural bone. This was achieved by modelling bone as a graded material and inserting node-specific values for Young's modulus in the finite element simulation, whereas the transition zone thickness was derived from a CT scan.

Fracture load of 4-unit interim fixed partial dentures using 3D-printed and traditionally manufactured materials.

Statement Of Problem: How the fracture strength of recently introduced 3-dimensionally (3D) printed interim materials compares with that of conventional materials is unclear.

Purpose: The purpose of this in vitro study was to compare the fracture load of 4-unit interim fixed partial dentures made from 3 different materials before and after mastication simulation.

Material And Methods: Based on a master model of a 4-unit fixed partial denture with maxillary left first premolar and second molar abutment teeth, interim restorations were fabricated from 3 different materials (3D-printed, Temporary CB Resin, milled, PMMA for brain, and manually manufactured, Luxatemp Plus).

The effect of surface treatments on the adhesive bond in all-ceramic dental crowns using four-point bending and dynamic loading tests.

The aim of this study was to determine the effect of sandblasting, grinding and plasma treatment on the adhesive bond strength between framework ceramic (Y-TZP) and veneering ceramic (feldspar ceramic). Therefore, four-point bending specimens (n = 180) were cut from densely sintered 3Y-TZP blanks. Subsequently, 80 of these samples received surface treatment by sandblasting and 80 samples by grinding.

Antibacterial properties and abrasion-stability: Development of a novel silver-compound material for orthodontic bracket application.

Purpose: Bacteria-induced white spot lesions are a common side effect of modern orthodontic treatment. Therefore, there is a need for novel orthodontic bracket materials with antibacterial properties that also resist long-term abrasion. The aim of this study was to investigate the abrasion-stable antibacterial properties of a newly developed, thoroughly silver-infiltrated material for orthodontic bracket application in an in situ experiment.

Fracture toughness of 3Y-TZP ceramic measured by the Chevron-Notch Beam method: A round-robin study.

Objective: This interlaboratory round robin test investigated the robustness of the Chevron-Notch Beam (CNB) test method and the effect of the processing and testing variations on the fracture toughness of a dental 3Y-TZP ceramic.

Methods: The round robin test was performed precisely following the procedures recommended in ISO 24370:2005 and applied on a commercial 3Y-TZP ceramic (product information). A total of 335 test specimens with dimensions 3×4 x 45 mm³ was equally distributed among 10 participating laboratories of varying experience in fracture toughness testing.

Abrasion Behavior of Different Charcoal Toothpastes on Human Dentin When Using Electric Toothbrushes.

The aim of this study was to investigate abrasion on human dentin after brushing with activated charcoal toothpastes. A self-designed brushing machine was used to brush five groups (Group A: Water, Group B: Sensodyne Pro Schmelz, Group C: Splat Blackwood, Group D: Curaprox Black is White, and Group E: Prokudent Black Brilliant) with electrically powered toothbrushes for 4 h. The abrasive dentin wear was calculated using profilometry data.

Abrasion Behaviour of Different Charcoal Toothpastes When Using Electric Toothbrushes.

Objectives: The purpose of this in vitro study was to compare the abrasion behaviour of different charcoal toothpastes when brushing with electric toothbrushes on human enamel.

Materials And Methods: A self-designed brushing machine was built using six commercially available electric toothbrushes in abrasion chambers. Each chamber was constantly supplied with a toothpaste-water mix.

Biaxial flexural strength of zirconia: A round robin test with 12 laboratories.

Objective: The aim of this interlaboratory round robin test was to prove the robustness of the DIN EN ISO 6872:2019 and to identify the influence of processing and testing variations.

Methods: Each of the 12 laboratories participated (A-L) received 60 (n = 720) assigned zirconia specimens. All participants seperated the specimens from the blanks, sintered them, polished half of all specimens and performed the biaxial flexural test (DIN EN ISO 6872:2019).

Liquid-Infused Structured Titanium Surfaces: Antiadhesive Mechanism to Repel Streptococcus oralis Biofilms.

To combat implant-associated infections, there is a need for novel materials which effectively inhibit bacterial biofilm formation. In the present study, the antiadhesive properties of titanium surface functionalization based on the "slippery liquid-infused porous surfaces" (SLIPS) principle were demonstrated and the underlying mechanism was analyzed. The immobilized liquid layer was stable over 13 days of continuous flow in an oral flow chamber system.

The effect of different occlusal contact situations on peri-implant bone stress - A contact finite element analysis of indirect axial loading.

Implant restoration is one of the basic treatments in dentistry today, yet implant loss from occlusal overload is still a problem. Complex biomechanical problems such as occlusal overload are often analyzed by means of the finite element method. This numerical method makes it possible to analyze in detail the influence that different loading situations have upon implants and tissues, which is a key element in optimizing these dental procedures.

The effect of direct and indirect force transmission on peri-implant bone stress - a contact finite element analysis.

In almost all finite element (FE) studies in dentistry, virtual forces are applied directly to dentures. The purpose of this study was to develop a FE model with non-linear contact simulation using an antagonist as force transmitter and to compare this with a similar model that uses direct force transmission. Furthermore, five contact situations were created in order to examine their influence on the peri-implant bone stresses, which are relevant to the survival rate of implants.

Stress Distribution in All-Ceramic Posterior 4-Unit Fixed Dental Prostheses Supported in Different Ways: Finite Element Analysis.

Introduction: The purpose of this finite element analysis (FEA) was to complement results of previously published studies that investigated the influence of abutment resilience on the load-bearing capacity of zirconia posterior 4-unit fixed dental prostheses (FDPs) with static load tests.

Materials And Methods: Duplicates of 3 different physical specimens were modeled for FEA. The first virtual specimen was supported by teeth with periodontal resilience, the second by the combination of tooth and implant, and the third by implants only.

Combined NC-AFM and DFT study of the adsorption geometry of trimesic acid on rutile TiO2(110).

The adsorption behavior of trimesic acid (TMA) on rutile TiO(2)(110) is studied by means of non-contact atomic force microscopy (NC-AFM) and density-functional theory (DFT). Upon low-coverage adsorption at room temperature, NC-AFM imaging reveals individual molecules, centered above the surface titanium rows. Based on the NC-AFM results alone it is difficult to deduce whether the molecules are lying flat or standing upright on the surface.