Numerical assessment of bone remodeling around conventionally and early loaded titanium and titanium-zirconium alloy dental implants.

The aim of this study was to investigate conventionally and early loaded titanium and titanium-zirconium alloy implants by three-dimensional finite element stress analysis. Three-dimensional model of a dental implant was created and a thread area was established as a region of interest in trabecular bone to study a localized part of the global model with a refined mesh. The peri-implant tissues around conventionally loaded (model 1) and early loaded (model 2) implants were implemented and were used to explore principal stresses, displacement values, and equivalent strains in the peri-implant region of titanium and titanium-zirconium implants under static load of 300 N with or without 30° inclination applied on top of the abutment surface.

A pilot study of joint stability at the zirconium or titanium abutment/titanium implant interface.

Purpose: To compare the interfaces of loaded and unloaded zirconium and titanium abutments with titanium implants using scanning electron microscopy (SEM).

Materials And Methods: Zirconium and titanium abutments (n = 5 per group; four test and one control) were torque-tightened into titanium implants secured into metal blocks, and computer-aided design/computer-assisted manufacture-based zirconium oxide copings were fabricated and cemented to the abutments with temporary resin-based cement. Specimens of each restoration were subjected to cyclic axial and lateral loading of 30 N at 2 Hz for 500,000 cycles using a servohydraulic test system; control specimens were left unloaded.

The effects of pulsed electromagnetic field (PEMF) on osteoblast-like cells cultured on titanium and titanium-zirconium surfaces.

Background: Commercially pure Ti, together with Ti Ni, Ti-6Al-4V, and Ti-6Al-7Nb alloys, are among the materials currently being used for this purpose. Titanium-zirconium (TiZr) has been developed that allows SLActive surface modification and that has comparable or better mechanical strength and improved biocompatibility compared with existing Ti alloys. Furthermore, approaches have targeted making the implant surface more hydrophilic, as with the Straumann SLActive surface, a modification of the SLA surface.

CAD/CAM glass ceramics for single-tooth implant crowns: a finite element analysis.

Purpose: To evaluate the load distribution of CAD/CAM mono-ceramic crowns supported with single-tooth implants in functional area.

Materials And Methods: A 3-dimensional numerical model of a soft tissue-level implant was constructed with cement-retained abutment to support glass ceramic machinable crown. Implant-abutment complex and the retained crown were embedded in a Ø 1.

Comparative assessments, meta-analysis, and recommended guidelines for reporting studies on histomorphometric bone-implant contact in humans.

Purpose: To evaluate factors that have an influence on histomorphometric bone-to-implant contact (BIC) of dental implants in humans.

Materials And Methods: Using inclusion/exclusion criteria, eligible studies were searched in five databases and handsearched in 11 journals. A total of 351 articles were assigned to full text analysis.

Predicting bone remodeling around tissue- and bone-level dental implants used in reduced bone width.

The objective of this study was to predict time-dependent bone remodeling around tissue- and bone-level dental implants used in patients with reduced bone width. The remodeling of bone around titanium tissue-level, and titanium and titanium-zirconium alloy bone-level implants was studied under 100 N oblique load for one month by implementing the Stanford theory into three-dimensional finite element models. Maximum principal stress, minimum principal stress, and strain energy density in peri-implant bone and displacement in x- and y- axes of the implant were evaluated.

Early-loaded one-stage implants retaining mandibular overdentures by two different mechanisms: 5-year results.

Purpose: To compare the biologic and prosthetic outcomes of implants loaded early to retain mandibular overdentures by means of two different attachment systems.

Materials And Methods: Patients were screened according to specific inclusion/exclusion criteria and randomly allocated to treatment groups involving two-implant-supported early loaded mandibular overdentures retained by ball attachments or Locator attachments. Marginal bone loss, Plaque Index, peri-implant infection, Bleeding Index, prosthetic complications, and Kaplan-Meier survival estimates of the groups were assessed at the 5-year recall.

Immediate versus conventional loading of implant-supported maxillary overdentures: a finite element stress analysis.

Purpose: To compare biomechanical outcomes of immediately and conventionally loaded bar-retained implant-supported maxillary overdentures using finite element stress analysis.

Materials And Methods: Finite element models were created to replicate the spatial positioning of four 4.1 × 12-mm implants in the completely edentulous maxillae of four cadavers to support bar-retained overdentures with 7-mm distal extension cantilevers.

A prospective, open-ended, single-cohort clinical trial on early loaded Titanium-zirconia alloy implants in partially edentulous patients: up-to-24-month results.

Purpose: To evaluate biologic and prosthetic outcomes of titanium-zirconia alloy implants supporting fixed prostheses.

Materials And Methods: A total of 52 titanium-zirconia alloy implants were placed in 23 consecutive patients with partial edentulism. All implants were subjected to an early loading protocol by means of single-unit or up-to-four-unit fixed partial prostheses and observed between 7 and 24 months.

Low-level laser therapy vs. pulsed electromagnetic field on neonatal rat calvarial osteoblast-like cells.

To compare the effects of pulsed electromagnetic field (PEMF) and low-level laser therapy (LLLT) on osteoblast cells in a cell culture model. Fifty thousand neonatal rat calvarial osteoblast-like cells per milliliter were seeded and 0.06 mT PEMF, 0.

Biomechanics of implant-tooth supported prostheses: effects of mesiodistal implant angulation and mode of prosthesis connection.

Purpose: The purpose of this study was to explore the effects of implant angulation and its possible influence on prosthetic connection as regards implant/tooth strains in a combined implant and natural tooth abutment fixed partial denture.

Methods: A natural tooth was embedded between vertically-aligned and 17° angulated implants in a polymethyl methacrylate acrylic resin model. Three designs (Group 1: tooth and vertically-aligned implant; Group 2: tooth and 17° angulated implant, Group 3: tooth and vertically-aligned implant having a different prosthetic connection to Group 1) of tooth-implant supported prostheses (n=4) were fabricated.

Do resin cements alter action potentials of isolated rat sciatic nerve?

Objectives: The purpose of this study was to explore the effects dual-cure resin cements on nerve conduction.

Methods: Panavia F, RelyX ARC, and Variolink II polymerized either by light-emitting diode (LED) or quartz tungsten halogen (QTH) were used in the study (n=10). The conductance of sciatic nerves of 50 rats were measured before and after contact with the specimens for 1 h.

A randomized controlled clinical trial of feldspathic versus glass-infiltrated alumina all-ceramic crowns: a 3-year follow-up.

Purpose: The aim of this randomized controlled clinical trial was to compare the outcome of feldspathic porcelain (group 1) and glass-infiltrated alumina all-ceramic (group 2) crowns.

Materials And Methods: Patients were recruited based on inclusion/exclusion criteria, and 33 eligible subjects were assigned randomly to one of the two treatment groups. One hundred one crowns were placed predominantly in the anterior portion of the mouth and were cemented using resin cement.

Astra Tech, Brånemark, and ITI implants in the rehabilitation of partial edentulism: two-year results.

Purpose: To explore the soft tissue, marginal bone, and prosthetic complications (if any) of Astra Tech, Brånemark, and ITI implants supporting fixed prostheses during an observation period of 2 years.

Materials: The study comprised 26 patients, who received 42 Astra Tech, 36 Brånemark, and 29 ITI implants. After 3 months of healing, abutment connections were performed for Astra Tech and Brånemark implants, and fixed prostheses were delivered to the patients at 4 months.

Spontaneous early exposure and marginal bone loss around conventionally and early-placed submerged implants: a double-blind study.

Purpose: The aim of this retrospective study was to compare the frequency of spontaneous early exposure of cover screws and marginal bone resorption in conventionally and early-placed submerged implants before second-stage surgery.

Materials And Methods: A total of 103 Nobel Biocare Branemark implants were conventionally (Group 1), or early-placed (Group 2) in 46 consecutive patients following the two-stage surgical protocol. Patients in both groups received oral hygiene training in self-performed plaque control measures, including exposure of cover screws during healing.

A systematic review of marginal bone loss around implants retaining or supporting overdentures.

Purpose: To evaluate, through a systematic review of the literature, the effects of implant design and attachment type on marginal bone loss in implant-retained/supported overdentures.

Materials And Methods: With the combined search terms "implant and overdenture," "implant-supported overdenture," "implant-retained overdenture," and "implant-anchored overdenture," along with specific inclusion and exclusion criteria, eligible articles between 1997 and 2008 (up to April 1) were retrieved from PubMed, EMBASE, OVID, the Cochrane Library databases, and seven journals by hand searching. Marginal bone loss values with regard to time, attachment type, and implant system used were compared by Kruskal-Wallis tests.

Systematic review of prosthetic maintenance requirements for implant-supported overdentures.

Purpose: To evaluate prosthetic maintenance requirements for implant-retained/supported overdentures via a review of the literature.

Materials And Methods: Using the combined search terms "implant and overdenture," "implant-supported overdenture," "implant-retained overdenture," and "implant-anchored overdenture," along with specific inclusion and exclusion criteria, eligible articles between 1997 and 2008 (up to April 1) were retrieved from PubMed, EMBASE, OVID, the Cochrane Library databases, and seven journals by hand-searching. The initial search yielded 3,120 titles, and 287 articles were assigned to full-text analysis.

Marginal bone loss and prosthetic maintenance of bar-retained implant-supported overdentures: a prospective study.

Purpose: To compare marginal bone loss, soft tissue conditions, and prosthetic outcomes of implants supporting mandibular and maxillary bar-retained overdentures.

Materials And Methods: A total of 124 implants (80 in the mandible and 44 in the maxilla) were placed in 35 patients. Bar-retained overdentures were fabricated for each patient.

Meta-analysis of methods used to assess implant stability.

Purpose: To evaluate correlations between Periotest, cutting torque or insertion torque, and/or the reverse torque test with resonance frequency analysis measurements.

Materials And Methods: The combined search terms dental implant, primary stability, resonance frequency analysis, removal torque, vibration analysis, torque, Periotest, cutting torque, and insertion torque and specific inclusion and exclusion criteria were used to retrieve eligible articles published between 1998 and 2008 (up to April 1) from PubMed, EMBASE, OVID, The Cochrane Library databases, and 10 journals by hand-searching. The pooled P value was calculated with the Fisher method.

Vascular smooth muscle contraction/relaxation of rat carotid artery is not altered by bone grafting substitutes in vitro.

Purpose: The aim of this study was to explore the effects of various bone grafting substitutes (Osteosponge, Perioglas, Tutoplast, and Surgibone) on vascular smooth muscle tonus.

Methods: Bilateral carotid arteries were removed from rats and contraction/relaxation of isolated vessel rings were measured before and after contact with the biomaterials and then, for dose-dependent epinephrine and papaverin administrations, by a force displacement transducer. The data of each biomaterial group were collected by a computerized system and corresponding software at a sample rate of 1,000 kHz and were converted to contraction force.

Numeric simulation of time-dependent remodeling of bone around loaded oral implants.

Purpose: The objective of this study was to investigate the time-dependent biomechanics of marginal bone around osseointegrated dental implants within physiologic loading conditions.

Materials And Methods: The remodeling of marginal bone around a 4.1-mm-diameter, 10-mm-long implant was studied by implementing the Stanford theory into axisymmetric mathematical models simulating different bone support at the implant neck: 1-mm-thick cortical bone (model 1), 0.

Predicting time-dependent remodeling of bone around immediately loaded dental implants with different designs.

The purpose of this study was to predict time-dependent biomechanics of bone around cylindrical screw dental implants with different macrogeometric designs under simulated immediate loading condition. The remodeling of bone around a parallel-sided and a tapered dental implant of same length was studied under 100N oblique load by implementing the Stanford theory into three-dimensional finite element models. The results of the analyses were examined in five time intervals consisting loading immediately after implant placement, and after 1, 2, 3 and 4 weeks following implantation.

Implant stability and bone density: assessment of correlation in fresh cadavers using conventional and osteotome implant sockets.

Objective: To compare the primary stability of implants placed in conventional and osteotome sites and to evaluate the level of correlation between cutting torque measurements, resonance frequency analysis (RFA), and bone density.

Materials And Methods: Eight human femoral heads were scanned with computed tomography for bone density measurements as Hounsfield units (HU), and individualized computed tomography-based surgical stents were prepared for placement of implants. Five implant sockets were prepared in each collum (CoF), caput (CaF), and trochanter (Tr-MM) section of the femoral heads using the conventional drilling technique or by a combination of drilling and use of an osteotome.

Nonlinear finite element analysis versus ex vivo strain gauge measurements on immediately loaded implants.

Purpose: To evaluate the level of agreement between nonlinear finite element stress analysis (NL-FEA) and ex vivo strain gauge analysis (EV-SGA) on immediately loaded implants.

Materials And Methods: Four 4.1-mm-diameter, 12-mm-long implants were placed bilaterally into the lateral and first premolar regions of completely edentulous maxillae of four human cadavers.

Fresh-frozen vs. embalmed bone: is it possible to use formalin-fixed human bone for biomechanical experiments on implants?

Purpose: As formalin is an extremely reactive electrophilic chemical that reacts with tissues, the purpose of this study was to explore whether formalin fixation could potentially alter the mechanical properties of bone tissue and have an effect on the primary stability measurements of implants.

Material And Methods: Ø 3.3 x 8 mm, Ø 4.