Grinding damage assessment for CAD-CAM restorative materials.

Objectives: To assess surface/subsurface damage after grinding with diamond discs on five CAD-CAM restorative materials and to estimate potential losses in strength based on crack size measurements of the generated damage.

Methods: The materials tested were: Lithium disilicate (LIT) glass-ceramic (e.max CAD), leucite glass-ceramic (LEU) (Empress CAD), feldspar ceramic (VM2) (Vita Mark II), feldspar ceramic-resin infiltrated (EN) (Enamic) and a composite reinforced with nano ceramics (LU) (Lava Ultimate).

Peri-implant bone adaptations to overloading in rat tibiae: experimental investigations and numerical predictions.

Objectives: (i) To assess the effects of mechanical overloading on implant integration in rat tibiae, and (ii) to numerically predict peri-implant bone adaptation.

Materials And Methods: Transcutaneous titanium implants were simultaneously placed into both tibiae of rats (n = 40). After 2 weeks of integration, the implants of the right tibiae were stimulated daily for 4 weeks with loads up to 5N (corresponding to peak equivalent strains of 3300 ± 500 με).

Numerical prediction of peri-implant bone adaptation: Comparison of mechanical stimuli and sensitivity to modeling parameters.

Long term durability of osseointegrated implants depends on bone adaptation to stress and strain occurring in proximity of the prosthesis. Mechanical overloading, as well as disuse, may reduce the stability of implants by provoking bone resorption. However, an appropriate mechanical environment can improve integration.

Large Bone Vertical Augmentation Using a Three-Dimensional Printed TCP/HA Bone Graft: A Pilot Study in Dog Mandible.

Background: Osteoflux is a three-dimensional printed calcium phosphate porous structure for oral bone augmentation. It is a mechanically stable scaffold with a well-defined interconnectivity and can be readily shaped to conform to the bone bed's morphology.

Purpose: An animal experiment is reported whose aim was to assess the performance and safety of the scaffold in promoting vertical growth of cortical bone in the mandible.

Grinding damage assessment on four high-strength ceramics.

Objectives: The purpose of this study was to assess surface and subsurface damage on 4 CAD-CAM high-strength ceramics after grinding with diamond disks of 75 μm, 54 μm and 18 μm and to estimate strength losses based on damage crack sizes.

Methods: The materials tested were: 3Y-TZP (Lava), dense Al2O3 (In-Ceram AL), alumina glass-infiltrated (In-Ceram ALUMINA) and alumina-zirconia glass-infiltrated (In-Ceram ZIRCONIA). Rectangular specimens with 2 mirror polished orthogonal sides were bonded pairwise together prior to degrading the top polished surface with diamond disks of either 75 μm, 54 μm or 18 μm.

Modulation of osteoblast behavior on TiNxOy coatings by altering the N/O stoichiometry while maintaining a high thrombogenic potential.

Introduction: Titanium nitride oxide (TiNxOy) coatings are known to stimulate osteoblast proliferation and osseointegration when compared to microrough titanium implants. The objectives of the present study were to determine whether the beneficial effects of TiNxOy coatings observed with implant osseointegration are dependent on N/O stoichiometry, with the final goal of optimizing these benefits. MMS: TiNxOy coatings with various N/O compositions were deposited on microrough titanium plates (Ti-SLA, 11 × 11 mm).

A 3D printed TCP/HA structure as a new osteoconductive scaffold for vertical bone augmentation.

Introduction: OsteoFlux(®) (OF) is a 3D printed porous block of layered strands of tricalcium phosphate (TCP) and hydroxyapatite. Its porosity and interconnectivity are defined, and it can be readily shaped to conform the bone bed's morphology. We investigated the performance of OF as a scaffold to promote the vertical growth of cortical bone in a sheep calvarial model.

Influence of gait loads on implant integration in rat tibiae: experimental and numerical analysis.

Implanted rat bones play a key role in studies involving fracture healing, bone diseases or drugs delivery among other themes. In most of these studies the implants integration also depends on the animal daily activity and musculoskeletal loads, which affect the implants mechanical environment. However, the tissue adaption to the physiological loads is often filtered through control groups or not inspected.

External mechanical microstimuli modulate the osseointegration of titanium implants in rat tibiae.

Purpose: To assess the effect of external mechanical microstimuli of controlled magnitude on the microarchitecture of the peri-implant bone beds in rat tibiae.

Materials And Methods: Tibiae of forty rats were fitted with two transcutaneous titanium cylinders. After healing, the implants were loaded to 1 to 3 N, five days/week for four weeks.

Factors affecting subject-specific finite element models of implant-fitted rat bone specimens: critical analysis of a technical protocol.

The authors propose a protocol to derive finite element (FE) models from micro computer tomography scans of implanted rat bone. A semi-automatic procedure allows segmenting the images using specimen-specific bone mineral density (BMD) thresholds. An open-source FE model generator processes the segmented images to a quality tetrahedral mesh.

Consensus report - reconstructions on implants. The Third EAO Consensus Conference 2012.

Introduction: This group was assigned the task to review the current knowledge in the areas of implant connections to abutments/reconstructions, fixation methods (cement vs. screw retained) for implant-supported reconstructions, as well as the optimal number of implants for fixed dental prosthesis and implant-supported overdentures.

Material And Methods: The literature was systematically searched and critically reviewed.

The role of the fluid phase in the viscous response of bovine periodontal ligament.

The mechanical response of the periodontal ligament (PDL) is complex. This tissue responds as a hyperelastic solid when pulled in tension while demonstrating a viscous behavior under compression. This intricacy is reflected in the tissue's morphology, which comprises fibers, glycosaminoglycans, a jagged interface with the surrounding porous bone and an extensive vascular network.

Mechanical response of periodontal ligament: effects of specimen geometry, preconditioning cycles and time lapse.

This study was conducted as part of research line addressing the mechanical response of periodontal ligament (PDL) to tensile-compressive sinusoidal loading. The aim of the present project was to determine the effect of three potential sources of variability: (1) specimen geometry, (2) tissue preconditioning and (3) tissue structural degradation over time. For the three conditions, selected mechanical parameters were evaluated and compared.

Regional structural characteristics of bovine periodontal ligament samples and their suitability for biomechanical tests.

Mechanical testing of the periodontal ligament requires a practical experimental model. Bovine teeth are advantageous in terms of size and availability, but information is lacking as to the anatomy and histology of their periodontium. The aim of this study, therefore, was to characterize the anatomy and histology of the attachment apparatus in fully erupted bovine mandibular first molars.

Mechanical and structural characteristics of commercially pure grade 2 Ti welds and solder joints.

This study aimed at determining whether data previously gathered for a laser welds and IR brazings using a Au-Pd alloy were applicable to titanium joints. As to its resistance under fatigue loading, Au-Pd alloy had shown a poor response to pre-ceramic laser welding and post-ceramic brazing. The present study was designed to assess the mechanical resistance, the microstructure and the elemental diffusion of laser welded, electric arch welded and brazed joints using commercially pure titanium as substrate metal.

Monotonic flexure and fatigue strength of composites for provisional and definitive restorations.

Statement Of Problem: Ordinarily, the mechanical strength of composites is characterized by their flexural strength. Information as to the material's fatigue strength is seldom provided.

Purpose: The purpose of this study was to compare the flexural strength and the resistance to fatigue loading of composites and an acrylic resin for provisional and definitive restorations.

Fatigue resistance of ITI implant-abutment connectors -- a comparison of the standard cone with a novel internally keyed design.

The Straumann Company has recently supplemented its standard 'morse-taper' configuration with an octagonal internal key. During the restorative phase of implant treatment, this additional feature was designed to ensure positional duplicability between the laboratory and the clinical environments. It was, however, unclear whether this keying mechanism would decrease the mechanical strength of the connection between the implant and the abutment.

In vivo wear of three types of veneering materials using implant-supported restorations: a method evaluation.

In a previous study, we determined the precision and the positional duplicability of a system that used implant connectors to transfer restorations between the oral cavity and the measuring device. The objectives of the present study were to determine whether this testing procedure was suitable for clinical use, and to apply the procedure to the longitudinal assessment of the wear of three types of veneering materials. Ten patients received a total of 12 restorations.

Fixed prosthodontics centric relation registration technique using resin copings.

The registration of an accurate centric relation is one of the most critical steps in a prosthodontic rehabilitation, yet it sometimes is an uncertain procedure. A technique using resin copings, each supporting an occlusal contact, is presented. By careful, selective addition of resin, the centric relation recording can be controlled.