Influence of Connection Types and Implant Number on the Biomechanical Behavior of Mandibular Full-Arch Rehabilitation.

Purpose: To evaluate the influence of different implant numbers and connection types on the biomechanical behavior of mandibular full-arch implant-supported rehabilitation.

Materials And Methods: Computed tomography-based finite element models comprising a totally edentulous mandible and 3.8 × 13-mmdiameter implants, abutments, abutment screws, bar retaining screw, and bar were constructed.

Bone Remodeling Around Implants with External Hexagon and Morse-Taper Connections: A Randomized, Controlled, Split-Mouth, Clinical Trial.

Objectives: To evaluate clinical, radiographic, microbiologic, and biomechanical parameters related to bone remodeling around implants with external hexagon (EH) and Morse-taper (MT) connections.

Materials And Methods: Twelve totally edentulous patients received four custom-made implants in the interforaminal region of the mandible. Two of those implants had the same macroscopic design, but different prosthetic connections.

Biomechanical evaluation of platform switching: different mismatch sizes, connection types, and implant protocols.

Background: It is not yet well understood to what extent different implant-abutment mismatch sizes and implant-abutment connection types may influence the peri-implant biomechanical environment of implants in different clinical situations.

Methods: Computed tomography-based finite element models comprising a maxillary central incisor socket and 4.5 × 13 mm outer-diameter implants with external and internal hex connection types were constructed.

Numerical simulation of the insertion process of an uncemented hip prosthesis in order to evaluate the influence of residual stress and contact distribution on the stem initial stability.

The long-term success of a cementless total hip arthroplasty depends on the implant geometry and interface bonding characteristics (fit, coating and ingrowth) and on stem stiffness. This study evaluates the influence of stem geometry and fitting conditions on the evolution and distribution of the bone-stem contact, stress and strain during and after the hip stem insertion, by means of dynamic finite element techniques. Next, the influence of the mechanical state (bone-stem contact, stress and strain) resulted from the insertion process on the stem initial resistance to subsidence is investigated.

Influence of implant design on the biomechanical environment of immediately placed implants: computed tomography-based nonlinear three-dimensional finite element analysis.

Purpose: To evaluate the influence of different implant designs on the biomechanical environment of immediately placed implants.

Materials And Methods: Computed tomography (CT)-based finite element models comprising a maxillary central incisor socket and four commercially available internal-connection implants (SIN SW, 3i Certain, Nobel Replace, and ITI Standard) of comparable diameters and lengths were constructed. Biomechanical scenarios of immediate placement, immediate loading, and delayed loading protocols were simulated.

Constant strain rate and peri-implant bone modeling: an in vivo longitudinal micro-CT analysis.

Background: Strain, frequency, loading time, and strain rate, among others, determine mechanical parameters in osteogenic loading. We showed a significant osteogenic effect on bone mass (BM) by daily peri-implant loading at 1.600µε.

Fast and accurate specimen-specific simulation of trabecular bone elastic modulus using novel beam-shell finite element models.

Elastic modulus and strength of trabecular bone are negatively affected by osteoporosis and other metabolic bone diseases. Micro-computed tomography-based beam models have been presented as a fast and accurate way to determine bone competence. However, these models are not accurate for trabecular bone specimens with a high number of plate-like trabeculae.

Biomechanical evaluation of platform switching in different implant protocols: computed tomography-based three-dimensional finite element analysis.

Purpose: To evaluate the influence of platform switching on the biomechanical environment of implants in different placement and loading protocols.

Materials And Methods: A computed tomography-based finite element model of a maxillary central incisor extraction socket was constructed containing a conical 13-mm external-hex implant with a 4.3-mm-diameter shoulder.

Micro-CT based quantitative evaluation of caries excavation.

Objectives: To optimize a microtomographic (micro-CT) technique to quantitatively evaluate the effectiveness of contemporary caries-excavation techniques.

Methods: A beam-hardening curve was obtained from an initial reconstruction of a wedge-shaped hydroxyapatite (HAp) block and fitted with a 5th order polynomial function, after which each micro-CT tooth slice was corrected accordingly. Calibration of the 8-bit gray values into mineral-density values was obtained by scanning, reconstructing and processing volume of interests (VOIs) of HAp phantoms with different mineral densities (0.

Influence of implant connection type on the biomechanical environment of immediately placed implants - CT-based nonlinear, three-dimensional finite element analysis.

Purpose: The purpose of the present study was to evaluate the biomechanical environment of immediately placed implants, before and after osseointegration, by comparing three different implant-abutment connection types.

Materials And Methods: A computer tomography-based finite element model of an upper central incisor extraction socket was constructed containing implants with either external hex, internal hex, or Morse-taper connection. Frictional contact elements were used in the bone, implant, abutment, and abutment screw interfaces in the immediately placed simulations.

In vivo evaluation of a vibration analysis technique for the per-operative monitoring of the fixation of hip prostheses.

Background: The per-operative assessment of primary stem stability may help to improve the performance of total hip replacement. Vibration analysis methods have been successfully used to assess dental implant stability, to monitor fracture healing and to measure bone mechanical properties. The objective of the present study was to evaluate in vivo a vibration analysis-based endpoint criterion for the insertion of the stem by successive surgeon-controlled hammer blows.

Assessment of the primary rotational stability of uncemented hip stems using an analytical model: comparison with finite element analyses.

Background: Sufficient primary stability is a prerequisite for the clinical success of cementless implants. Therefore, it is important to have an estimation of the primary stability that can be achieved with new stem designs in a pre-clinical trial. Fast assessment of the primary stability is also useful in the preoperative planning of total hip replacements, and to an even larger extent in intraoperatively custom-made prosthesis systems, which result in a wide variety of stem geometries.

Effect of strain at low-frequency loading on peri-implant bone (re)modelling: a guinea-pig experimental study.

Objectives: To investigate whether controlled early loading enhances peri-implant bone mass and bone-to-implant contact. Low-frequency stimulation (3 Hz) and varying force amplitudes, causing varying strains, were applied in three guinea-pig series.

Material And Methods: Three series of guinea-pigs received percutaneous TiO(2)-blasted implants in both tibiae.

Effect of controlled early implant loading on bone healing and bone mass in guinea pigs, as assessed by micro-CT and histology.

Without controlled loading, the failure of early loaded oral implants is higher than in delayed loading, unless loading regimens can be identified that stimulate bone formation. The purpose of this study was to investigate whether controlled early loading optimizes osseointegration. Six series of guinea pigs received percutaneous implants in both tibiae.