Hydrothermal degradation of a 3Y-TZP translucent dental ceramic: A comparison of numerical predictions with experimental data after 2 years of aging.

Objectives: The purpose of the study was to assess the hydrothermal resistance of a translucent zirconia with two clinical relevant surface textures by means of accelerated tests (LTD) and to compare predicted monoclinic fractions with experimental values measured after two years aging at 37°C.

Methods: Polished (P) and ground (G) specimens were subjected to hydrothermal degradation by exposure to water steam at different temperatures and pressures. The t-m phase transformation was quantified by grazing incidence X-ray diffraction (GIXDR).

Three- to nine-year survival estimates and fracture mechanisms of zirconia- and alumina-based restorations using standardized criteria to distinguish the severity of ceramic fractures.

Objectives: The aims of this study were set as follows: 1. To provide verifiable criteria to categorize the ceramic fractures into non-critical (i.e.

TiNOx coatings increase human primary osteoblasts proliferation independently of the substrate: a short report.

Introduction: When applied onto SLA titanium, Titanium Nitride Oxide (TiNOx) coatings are known for their stimulating effect on osteoblast proliferation while maintaining a high degree of differentiation.

Objective: To determine whether the stimulating effect of TiNOx coatings is or is not dependent of the metal substrate.

Methods: A TiNOx coating was deposited on roughened stainless steel (SS-SLA-TiNOx).

TiNOx coatings on roughened titanium and CoCr alloy accelerate early osseointegration of dental implants in minipigs.

Introduction: Titanium nitride oxide (TiNOx) coatings are known for their biocompatibility, hardness and high resistance to corrosion and wear. Further, they can be applied by plasma vapor deposition onto a wide variety of metallic, mineral, or organic substrates. In cell cultures, TiNOx coatings applied onto SLA (sandblasted, large grit, acid etched)-roughened titanium surfaces increased human primary osteoblast proliferation by 1.

Implementation of the "loaded implant" model in the rat using a miniaturized setup--description of the method and first results.

Objective: To miniaturize the "loaded implant" model to permit its application to small rodents. In this model, two titanium implants are placed 8 mm apart with their heads protruding from the skin and are forced together by a dedicated actuator. To assess the effect of (i) the post-implantation healing period and the duration of stimulation and (ii) the intratissular strain level on the microtomographical bone parameters BV/TV, Tb.

Resistance of three implant-abutment interfaces to fatigue testing.

Unlabelled: The design and retentive properties of implant-abutment connectors affect the mechanical resistance of implants. A number of studies have been carried out to compare the efficacy of connecting mechanisms between abutment and fixture.

Objectives: The aims of this study were: 1) to compare 3 implant-abutment interfaces (external hexagon, internal hexagon and cone-in-cone) regarding the fatigue resistance of the prosthetic screw, 2) to evaluate the corresponding mode of failure, and 3) to compare the results of this study with data obtained in previous studies on Nobel Biocare and Straumann connectors.

Titanium nitride oxide coating on rough titanium stimulates the proliferation of human primary osteoblasts.

Objectives: Titanium is widely used in contemporary endosseous implantology and there is considerable thrust to further promote osseointegration by implant surface modifications. The aim of this study was to evaluate the effect of a titanium-nitride-oxide (TiNOx) coating on commercially pure microroughened titanium by assessing the proliferation and differentiation of human primary osteoblasts.

Materials And Methods: Cell proliferation, gene expression, alkaline phosphatase activity, osteoprotegerin and osteocalcin secretion were analyzed for a time course of 3 weeks, with or without additional stimulation by 1.

Fatigue behavior in water of Y-TZP zirconia ceramics after abrasion with 30 μm silica-coated alumina particles.

Objective: The use of a 30 μm alumina-silica coated particle sand (CoJet™ Sand, 3M Espe), has shown to enhance the adhesion of resin cements to Y-TZP. The question is whether or not sandblasting 30 μm particles does negatively affect the fatigue limit (S-N curves) and the cumulative survival of Y-TZP ceramics.

Method: Four zirconia materials tested were: Zeno (ZW) (Wieland), Everest ZS (KV) (KaVo), Lava white (LV) and Lava colored (LVB) (3M Espe).

Low temperature degradation of a Y-TZP dental ceramic.

Bars of Y-TZP ceramic for dental restorations were subjected to hydrothermal degradation via in vitro exposure to water steam at 140°C for 7 days. X-ray diffraction, atomic force microscopy and scanning electron microscopy techniques were applied to observe and quantify the tetragonal-monoclinic (t-m) phase transformation associated with the process. Nanoindentation was used to assess the ceramic's mechanical properties before and after hydrothermal degradation.

Surface roughness and EDS characterization of a Y-TZP dental ceramic treated with the CoJet™ Sand.

Objectives: (1) To determine the surface roughness and material loss of a Y-TZP ceramic before and after tribochemical grit blasting and (2) to characterize the changes in elemental surface composition and the phase transformations after tribochemical treatment.

Methods: Machined bar shaped specimens (Zeno, Wieland) were subdivided into three groups. After grit blasting for 10, 20 and 30s respectively, half of the specimens of each group were ultrasonically cleaned in ethanol for 10min.

Hydro-mechanical coupling in the periodontal ligament: a porohyperelastic finite element model.

Harmonic tension-compression tests at 0.1, 0.5 and 1 Hz on hydrated bovine periodontal ligament (PDL) were numerically simulated.

Three-dimensional morphometry of strained bovine periodontal ligament using synchrotron radiation-based tomography.

The periodontal ligament (PDL) is a highly vascularized soft connective tissue. Previous studies suggest that the viscous component of the mechanical response may be explained by the deformation-induced collapse and expansion of internal voids (i.e.

Load response of periodontal ligament: assessment of fluid flow, compressibility, and effect of pore pressure.

The periodontal ligament (PDL) functions both in tension and in compression. The presence of an extensive vascular network inside the tissue suggests a significant contribution of the fluid phase to the mechanical response. This study examined the load response of bovine PDL under different pore pressure levels.

The effect of water storage, elapsed time and contaminants on the bond strength and interfacial polymerization of a nanohybrid composite.

Purpose: To systematically characterize the effect of time lapse, water storage, and selected contaminants on the bond strength of a nanofilled dental composite.

Materials And Methods: Half-dumbbell-shaped samples were fabricated out of light-polymerizing composite resin. To function as substrates they were aged for 30 days in water.

Ceramics in implant dentistry (Working Group 1).

Introduction: The remit of this working group was to update the existing knowledge base in ceramics in implant dentistry. The reviews from working group 1 formed the basis for this update. Moreover, clinical applications as well as suggestions for further research have been formulated.

Bone reactions to controlled loading of endosseous implants: a pilot study.

Objectives: To validate an experimental setup designed to apply load onto bone tissue using osseointegrated implants in a rabbit model. Specifically, (1) to design an apparatus capable of generating controlled forces, (2) to assess implant placement, maintenance and loading and (3) to evaluate outcome variables using three radiological methods.

Material And Methods: New Zealand White rabbits were used.

Resistance of internal-connection implant connectors under rotational fatigue loading.

Purpose: To aid in developing mechanically optimized implant-abutment connectors, the fatigue resistance of 5 connector configurations of the Replace Select system (Easy abutment, Easy abutment without antirotational mechanism, Multi-unit abutment, Esthetic Alumina abutment, Esthetic Zirconia abutment) was investigated. Other purposes of the study were to determine whether the connector's antirotational mechanism participates in fatigue resistance and to compare the results with previous data on Straumann connectors.

Materials And Methods: The repetitive, alternating, and multivectorial intraoral force pattern was reproduced by subjecting the test specimens to the rotating cantilever beam test.

Fractographic ceramic failure analysis using the replica technique.

Objectives: To demonstrate the effectiveness of in vivo replicas of fractured ceramic surfaces for descriptive fractography as applied to the analysis of clinical failures.

Methods: The fracture surface topography of partially failed veneering ceramic of a Procera Alumina molar and an In-Ceram Zirconia premolar were examined utilizing gold-coated epoxy poured replicas viewed using scanning electron microscopy. The replicas were inspected for fractographic features such as hackle, wake hackle, twist hackle, compression curl and arrest lines for determination of the direction of crack propagation and location of the origin.

Rotational fatigue-resistance of seven post types anchored on natural teeth.

Purpose: To develop a laboratory model aimed at duplicating the failure process of post and core restorations. The load pattern applied was to be repetitive (fatigue) and multivectorial. To determine and compare the resistance under fatigue loading of seven endodontic post/natural root combinations: stainless steel-, titanium-, ceramic-, composite-fiber/epoxy-, two glass-fiber/epoxy- and glass-fiber/acrylic posts.

Using implant connectors to support clinical abrasion probes: a methodological study.

Objectives: To validate a procedure aimed at assessing the clinical wear rate of full crown veneering materials. To confirm its clinical applicability and alignment capacity in the ancillary profiling apparatus. To quantify the wear rate of a full crown veneering composite (Sinfony, 3M-ESPE) as compared to that of a ceramic (negative control) and an unfilled resin (positive control).

Biomechanical aspects of oral implants. Consensus report of Working Group 1.

The method used by the working group was an iterative process based upon a structured review of the relevant literature by a group of reporters. The review papers were circulated to the members of the group before the conference and formed the basis for subsequent discussions. Each paper was subject to detailed collective analysis and subsequently modified on the basis of the panel's discussions and referenced to additional relevant literature where appropriate.

Oscillatory shear loading of bovine periodontal ligament--a methodological study.

This study examined the stress response of bovine periodontal ligament (PDL) under sinusoidal straining. The principle of the test consisted in subjecting transverse tooth, PDL and bone sections of known geometries to controlled oscillatory force application. The samples were secured to the actuator by support plates fabricated using a laser sintering technique to fit their contours to the tooth and the alveolar bone.

In vitro time-dependent response of periodontal ligament to mechanical loading.

This study examined the time-dependent response of bovine periodontal ligament (PDL). Applying linear viscoelastic theory, the objective was 1) to examine the linearity of the PDL's response in terms of its scaling and superposition property and 2) to generate the phase lag-vs.-frequency spectrum graph.

Resistance of ITI implant connectors to multivectorial fatigue load application.

Purpose: In an effort to provide patients with mechanically optimized implant connectors, this study was designed to assess the relative fatigue resistance of five types of connectors for the ITI implant system: (1) standard (screw-on) abutments torqued to 35, 70, and 140 Ncm; (2) metal Octa connectors torqued to 35 Ncm; (3) ceramic Octa connectors torqued to 15 and 35 Ncm; (4) cemented cast-on abutments; and (5) an experimental screw-retained composite core.

Materials And Methods: To duplicate the alternating and multivectorial intraoral loading patterns, the specimens were subjected to the rotating cantilever beam test. The implants, their connectors, and abutments were spun around their longitudinal axes while a perpendicular force was applied to the external end.

Reversible and irreversible peri-implant lesions: report and etiopathogenic analysis of 7 cases.

The purpose of this report is to review the aberrations in the integration process of cylindrical endosseous implants, though such aberrations are seldom observed. These issues are treated according to the following scheme: (1) infectious lesions, which consist of peri-implantitis, intraosseous infectious foci, and septic voids; (2) transitory lesions; (3) lesions related to occlusal overload; and (4) healing defects. In this report, we illustrate these categories with patient histories and discuss the clinical findings and etiopathogenies.