Comparative Analysis of Bone Stresses and Strains in the Intoss dental Implant with and without a Flexible Internal Post

1995 ◽  
Vol 209 (3) ◽  
pp. 139-147 ◽  
Author(s):  
S E Clift ◽  
J Fisher ◽  
B N Edwards
Keyword(s):  
Thin Layer ◽  
Cortical Bone ◽  
Dental Implant ◽  
Cancellous Bone ◽  
Load Transfer ◽  
Clinical Success ◽  
Equivalent Strain ◽  
Lateral Loading ◽  
Implant Design ◽  
Standard Implant

The clinical success of any dental implant is dependent upon the maintenance of good-quality bone supporting it. Previous studies have shown high values of strain around the neck of an implant under lateral loading. These high values may lead to fatigue damage and resorption in lower strength cancellous bone. In this study, the finite element method has been used to study the bone strain distribution around the following implants: (a) an Intoss dental implant, referred to as the ‘standard’ implant; (b) a comparative Branemark implant and (c) a modified Intoss implant with a central flexible post, referred to as the ‘modified’ implant. Three different bone distributions have been investigated under axial and lateral loading: (a) implant surrounded by cortical bone; (b) implant tip supported by cortical bone with a thin layer of cancellous bone along the length and top of the implant; (c) implant tip and top supported by cortical bone with a thin layer of cancellous bone along the remaining length. For the standard implant, similar maximum equivalent strain values were predicted for the bone surrounding a comparable length Branemark-type implant. Modification of the standard implant design to include a flexible central post resulted in a decrease in the maximum von Mises stresses and equivalent strains in the cancellous bone. It is postulated that this will reduce the likelihood of bone fatigue failure and subsequent resorption in this bone. Thus the proposed design change is predicted to be highly beneficial in terms of bone load transfer.

scholarly journals New Implant Design with Midcrestal and Apical Wing Thread for Increased Implant Stability in Single Postextraction Maxillary Implant

2019 ◽  
Vol 2019 ◽  
pp. 1-4 ◽  
Author(s):  
Antonio Scarano ◽  
Bartolomeo Assenza ◽  
Francesco Inchingolo ◽  
Filiberto Mastrangelo ◽  
Felice Lorusso
Keyword(s):  
Cortical Bone ◽  
Dental Implant ◽  
Alveolar Bone ◽  
Primary Stability ◽  
Implant Design ◽  
Insertion Torque ◽  
Fixture Design ◽  
Implant Stability ◽  
Implant Placement ◽  
Immediate Placement

Background. The immediate placement of a dental implant could represent an option treatment for the rehabilitation of a postextractive missing tooth socket to replace compromised or untreatable teeth, with the advantage of single-session surgery. In this way, the anatomy of the alveolar bone defect, the preservation of the buccal cortical bone, and the primary stability of the fixture represent the critical factors that consent a precise implant placement. Objective. This case report describes a novel fixture design for postextractive alveolar socket immediate implant. Methods. Two patients (25 and 31 years old) were treated for postextractive dental implant placement to replace both central upper incisor teeth with four implants. The residual bone implant gap was not filled with graft or bone substitute. The restoration was provided following a standard loading protocol by a cement-sealed prosthetic abutment. Results. Clinically, all implants positioned showed an excellent insertion torque. No postoperative complications were reported. At 6 months of healing, the buccal cortical bone and the implant stability were present and well maintained. Conclusion. The evidence of this study allows us to underline the possible advantages of this new fixture design for postextractive implant technique.

scholarly journals Relationship between Cortical Bone Thickness and Cancellous Bone Density at Dental Implant Sites in the Jawbone

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 710
Author(s):  
Shiuan-Hui Wang ◽  
Yen-Wen Shen ◽  
Lih-Jyh Fuh ◽  
Shin-Lei Peng ◽  
Ming-Tzu Tsai ◽  
...  
Keyword(s):  
Bone Density ◽  
Cortical Bone ◽  
Dental Implant ◽  
Cancellous Bone ◽  
Bone Thickness ◽  
Anterior Maxilla ◽  
Cortical Bone Thickness ◽  
Posterior Maxilla ◽  
Dental Implant Surgery ◽  
Anterior Mandible

Dental implant surgery is a common treatment for missing teeth. Its survival rate is considerably affected by host bone quality and quantity, which is often assessed prior to surgery through dental cone-beam computed tomography (CBCT). Dental CBCT was used in this study to evaluate dental implant sites for (1) differences in and (2) correlations between cancellous bone density and cortical bone thickness among four regions of the jawbone. In total, 315 dental implant sites (39 in the anterior mandible, 42 in the anterior maxilla, 107 in the posterior mandible, and 127 in the posterior maxilla) were identified in dental CBCT images from 128 patients. All CBCT images were loaded into Mimics 15.0 to measure cancellous bone density (unit: grayscale value (GV) and cortical bone thickness (unit: mm)). Differences among the four regions of the jawbone were evaluated using one-way analysis of variance and Scheffe’s posttest. Pearson coefficients for correlations between cancellous bone density and cortical bone thickness were also calculated for the four jawbone regions. The results revealed that the mean cancellous bone density was highest in the anterior mandible (722 ± 227 GV), followed by the anterior maxilla (542 ± 208 GV), posterior mandible (535 ± 206 GV), and posterior maxilla (388 ± 206 GV). Cortical bone thickness was highest in the posterior mandible (1.15 ± 0.42 mm), followed by the anterior mandible (1.01 ± 0.32 mm), anterior maxilla (0.89 ± 0.26 mm), and posterior maxilla (0.72 ± 0.19 mm). In the whole jawbone, a weak correlation (r = 0.133, p = 0.041) was detected between cancellous bone density and cortical bone thickness. Furthermore, except for the anterior maxilla (r = 0.306, p = 0.048), no correlation between the two bone parameters was observed (all p > 0.05). Cancellous bone density and cortical bone thickness varies by implant site in the four regions of the jawbone. The cortical and cancellous bone of a jawbone dental implant site should be evaluated individually before surgery.

Influence of Dental Implant Design on Stress Distribution and Micromotion of Mandibular Bone

2020 ◽  
Vol 899 ◽  
pp. 81-93
Author(s):  
Nur Faiqa Ismail ◽  
M. Saiful Islam ◽  
Solehuddin Shuib ◽  
Rohana Ahmad ◽  
M. Amar Shahmin
Keyword(s):  
Shear Stress ◽  
Dental Implant ◽  
Cancellous Bone ◽  
3D Models ◽  
Von Mises Stress ◽  
Implant Design ◽  
Element Analysis ◽  
Reconstruction Process ◽  
Mandibular Bone ◽  
Von Mises

This research was conducted to provide a feasible method for reconstructing the 3D model of mandibular bone to undergo finite element analysis to investigate von Mises stress, deformation and shear stress located at the cortical bone, cancellous one and neck implant of the proposed dental implant design. Dental implant has become a significant remedial approach but although the success rate is high, the fixture failure may happen when there are insufficient host tissues to initiate and sustain the osseointegration. Computerised Tomography scan was conducted to generate head images for bone reconstruction process. MIMICS software and 3-matic software were used to develop the 3D mandibular model. The reconstructed mandibular model was then assembled with five different 3D models of dental implants. Feasible boundary conditions and material properties were assigned to the developed muscle areas and joints. The highest performance design with the best responses was the design B with the value for the von Mises stress for the neck implant, cortical and cancellous bone were 7.53 MPa, 16.91 MPa and 1.34 MPa respectively. The values for the maximum of micromotion for the neck implant, cortical and cancellous bone of design B were 20.60 μm, 21.17 μm and 5.83 μm respectively. Shear stress for neck implant, cortical and cancellous bone for this design were 0.15 MPa, 4.74 MPa and 1.54 MPa respectively. The design with a cone shaped hole which is design B was the proper design when compared with other designs in terms of von Misses stress, deformations and shear stress.

Biomechanical Comparison between Two Models of the Lumbar Intersomatic Fusion Cage Analyzed by the Finite Element Method

2017 ◽  
Vol 32 ◽  
pp. 40-58 ◽  
Author(s):  
Said Kebdani ◽  
S. Kebdani ◽  
M. Dahmane ◽  
Z. Azari
Keyword(s):  
Cortical Bone ◽  
Cancellous Bone ◽  
Lumbar Vertebra ◽  
Three Dimensions ◽  
Implant Design ◽  
Posterior Fixation ◽  
Eccentric Load ◽  
Initial Stability ◽  
Fusion Cage ◽  
Biomechanical Comparison

There are a few years, it has become the use of artificial discs and effectively to compensate for damaged discs in humans due to the eccentric load applied on the spine. As we know very well that the success of a disc implantation depends strongly on the initial stability of the implant and the integration of the bone tissue of the vertebrae with these discs in the long term. Due to the optimal distribution of mechanical stresses in the surrounding bone. It is for this reason that the search for reasonable solutions to compensate the damaged disk and reduce the stresses in the cortical bone and spongy has become a very important research axis. Several alternatives have been studied, including implant design, prosthesis geometry, prosthetic components and biomaterials used. In this regard, we have proposed two new models for some innovative artificial disks by some of the biomechanics researchers and we have installed these discs between the two vertebrae L5 and S1 of the spine, to ensure spinal stability and avoid slipping, we installed a posterior attachment system (6 screws plus 2 rods) at the pedicular levels of the lumbar vertebra (S1-L5, L5-L4).It is for this technique that we have used finite elements in three dimensions and using the software ANSYS to know the extent of the realization of these discs under the influence of the load applied to them. The numerical results show that these disks played a very important role in the absorption of the stresses and to minimize, On the other hand, the lumbar inter-somatic cage (Model II) filled with cancellous bone is too great a role in reducing the stress compared to another synthetic (Model I) disc. In general, the new model of the inter-somatic cage filled with cancellous bone and reinforced by a posterior fixation system has given a lower level of stress in the cortical bone and the spongy bone of the lumbar vertebra (L5) compared to the healthy disk (D1).

Effect of Cortical and Cancellous Bone Anisotropy on Peri-Implant Stresses and Strains in the Posterior Mandible

2000 ◽  
Author(s):  
Aisling M. O’Mahony ◽  
John L. Williams
Keyword(s):  
Cortical Bone ◽  
Dental Implant ◽  
Cancellous Bone ◽  
Elastic Constants ◽  
Transverse Isotropy ◽  
The Other ◽  
Bone Implant ◽  
Horizontal Loading ◽  
Principal Strains

Abstract We computed the bone-implant interface stresses for a bullet-shaped dental implant in the human mandible under combined vertical and horizontal loading. We also calculated the principal strains in the bone surrounding the implant. Two cases were compared: One in which the bone was considered to have isotropic elastic constants and the other in which transverse isotropy was assumed. Anisotropy increased the peak stresses and strains around both the implant-cancellous and implant-cortical bone interfaces.

Stress and Strain Distribution in the Bone Surrounding a New Design of Dental Implant: A Comparison with a Threaded Branemark Type Implant

1993 ◽  
Vol 207 (3) ◽  
pp. 133-138 ◽  
Author(s):  
S E Clift ◽  
J Fisher ◽  
C J Watson
Keyword(s):  
Stress Concentration ◽  
Dental Implant ◽  
Load Transfer ◽  
Bone Ingrowth ◽  
High Stress ◽  
Neck Region ◽  
Lateral Loading ◽  
Porous Coating ◽  
Stress And Strain ◽  
Bonded Interface

The stress and strain distributions in the bone surrounding a new dental implant, designed specifically for use with a bioactive porous coating and thus having a fully bonded interface to the bone, have been analysed. The new implant geometry was slightly tapered, with deep concentric grooves to allow bone ingrowth and load transfer, and had a parallel cylindrical section at the neck. The results have been compared with stress and strain predictions in the bone surrounding a ‘Branemark type’ threaded implant with a fully bonded interface. Under axial loading both implant types produced similar stress and strain distributions with a higher level of stress in the cortical bone surrounding the neck of the implant. Under lateral loading a high stress concentration was found in the neck region of both implants, but this was lower around the neck of the new design compared with the threaded implant. When the new implant was surrounded by cancellous bone, the reduction in the stress concentration was up to 50 per cent. This reduction should help to reduce fatigue failure and bone resorption in this area under lateral loading.

scholarly journals The sensitivity of contact stresses in the mandibular premolar region to the shape of Zirconia dental implant: A 3D finite element study

2018 ◽  
Vol 24 (2) ◽  
pp. 55-63 ◽  
Author(s):  
Duraisamy Velmurugan ◽  
Masilamany Santha Alphin ◽  
Benedict Jain AR Tony
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Cortical Bone ◽  
Transition Region ◽  
Dental Implant ◽  
Cancellous Bone ◽  
Contact Stresses ◽  
Thread Profile ◽  
Von Mises ◽  
Von Mises Stresses

Abstract Background: Implant thread profile plays a vital role in magnitude and distribution of contact stresses at the implant-bone interface. The main goal of this study was to evaluate the biomechanical effects of four distinct thread profiles of a dental implant in the mandibular premolar region. Methods: The dental implant represented the biocompatible Zirconia material and the bone block was modelled as transversely isotropic and elastic material. Three-dimensional finite element simulations were conducted for four distinct thread profiles of a dental implant at 50%, 75%, and 100% osseointegration. An axial static load of 500 N was applied on the abutment surface to estimate the stresses acting within the bones surrounding the implant. Results: Regions of stress concentration were seen mostly along the mesiodistal direction compared to that in the buccolingual direction. The cortical bone close to the cervical region of the implant and the cortical bone next to the first thread of the implant experienced peak stress concentration. Increasing the degree of osseointegration resulted in increased von-Mises stresses on the implant-cortical transition region, the implant-cancellous transition region, the cortical bone, and the cancellous bone. Conclusion: The results show that the application of distinct thread profiles at different degrees of osseointegration had significant effect on the stresses distribution contours in the surrounding bony structure. Comparing all four thread profiles, a dental implant with V-thread profile induced lower values of von-Mises stresses and shear stresses on the implant-cortical transition region, implant-cancellous transition region, cortical bone, and cancellous bone.

scholarly journals Finite Element Analysis of a New Dental Implant Design Optimized for the Desirable Stress Distribution in the Surrounding Bone Region

Prosthesis ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 225-236 ◽  
Author(s):  
Luigi Paracchini ◽  
Christian Barbieri ◽  
Mattia Redaelli ◽  
Domenico Di Croce ◽  
Corrado Vincenzi ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Dental Implant ◽  
Neck Region ◽  
Implant Design ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Surrounding Bone

Dental implant macro- and micro-shape should be designed to maximize the delivery of optimal favorable stresses in the surrounding bone region. The present study aimed to evaluate the stress distribution in cortical and cancellous bone surrounding two models of dental implants with the same diameter and length (4.0 × 11 mm) and different implant/neck design and thread patterns. Sample A was a standard cylindric implant with cylindric neck and V-shaped threads, and sample B was a new conical implant with reverse conical neck and with “nest shape” thread design, optimized for the favorable stress distribution in the peri-implant marginal bone region. Materials and methods: The three-dimensional model was composed of trabecular and cortical bone corresponding to the first premolar mandibular region. The response to static forces on the samples A and B were compared by finite element analysis (FEA) using an axial load of 100 N and an oblique load of 223.6 N (resulting from a vertical load of 100 N and a horizontal load of 200 N). Results: Both samples provided acceptable results under loadings, but the model B implant design showed lower strain values than the model A implant design, especially in cortical bone surrounding the neck region of the implant. Conclusions: Within the limitation of the present study, analyses suggest that the new dental implant design may minimize the transfer of stress to the peri-implant cortical bone.

Implant Biomechanics in Grafted Sinus: A Finite Element Analysis

2004 ◽  
Vol 30 (2) ◽  
pp. 59-68 ◽  
Author(s):  
Mete I. Fanuscu ◽  
Hung V. Vu ◽  
Bernard Poncelet
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Stress Reduction ◽  
Lateral Loading ◽  
Von Mises Stress ◽  
Finite Element Models ◽  
Native Bone ◽  
Clinical Scenarios

Abstract This in vitro study investigated the stress distribution in the bone surrounding an implant that is placed in a posterior edentulous maxilla with a sinus graft. The standard threaded implant and anatomy of the crestal cortical bone, cancellous bone, sinus floor cortical bone, and grafted bone were represented in the 3-dimensional finite element models. The thickness of the crestal cortical bone and stiffness of the graft were varied in the models to simulate different clinical scenarios, representing variation in the anatomy and graft quality. Axial and lateral loads were considered and the stresses developed in the supporting structures were analyzed. The finite element models showed different stress patterns associated with helical threads. The von Mises stress distribution indicated that stress was maximal around the top of the implant with varying intensities in both loading cases. The stress was highest in the cortical bone, lower in the grafted bone, and lowest in the cancellous bone. When the stiffness of the grafted bone approximated the cortical bone, axial loading resulted in stress reduction in all the native bone layers; however, lateral loading produced stress reduction in only the cancellous bone. When the stiffness of the graft was less than that of the cancellous bone, the graft assumed a lesser proportion of axial loads. Thus, it caused a concomitant stress increase in all the native bones, whereas this phenomenon was observed in only the cancellous bone with lateral loading. The crestal cortical bone, though receiving the highest intensity stresses, affected the overall stress distribution less than the grafted bone. The stress from the lateral load was up to 11 times higher than that of the axial load around the implant. These findings suggest that the type of loading affects the load distribution more than the variations in bone, and native bone is the primary supporting structure.

SHAPE OPTIMIZATION OF DENTAL IMPLANT DESIGNS UNDER OBLIQUE LOADING USING THE p-VERSION FINITE ELEMENT METHOD

2002 ◽  
Vol 02 (03n04) ◽  
pp. 339-345 ◽  
Author(s):  
CYNTHIA S. PETRIE ◽  
JOHN L. WILLIAMS
Keyword(s):  
Finite Element ◽  
Cortical Bone ◽  
Dental Implant ◽  
Cancellous Bone ◽  
Effective Means ◽  
Maximum Diameter ◽  
Low Density ◽  
Medium Density ◽  
Bone Model ◽  
Bone Strains

The aim of this study was to introduce design optimization of an endosseous dental implant in order to minimize cortical bone strains at the crest of the implant/bone interface. Linear elastic p-version finite element analysis was used to find the optimal design in four different two-dimensional finite element models of the mandibular bone: model 1 (medium density cancellous bone and 2 mm thickness of cortical bone), model 2 (low density cancellous bone and 2 mm thickness of cortical bone), model 3 (medium density cancellous bone and 1 mm thickness of cortical bone), model 4 (low density cancellous bone and 1 mm thickness of cortical bone). Shape of the implant was evaluated with respect to its length and diameter, as well as the presence or absence of taper in the neck. Implants with maximum length, maximum diameter, and no taper had the lowest crestal strains in models 1, 3, and 4. Taper in the neck of the implant increased the strains in models 1, 3, and 4. In cases of poor quality of bone, increasing the diameter of the implant appeared to be the most effective means of reducing crestal bone strains.

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