scholarly journals Effect of mucosa thicknesses on stress distribution of implant-supported overdentures under unilateral loading: Photoelastic analysis

2019 ◽  
Vol 17 (4) ◽  
pp. 228080001988264
Author(s):  
Ozgun Yusuf Ozyilmaz ◽  
Filiz Aykent ◽  
Gulsum Sayin Ozel
Keyword(s):  
Stress Distribution ◽  
Surrounding Tissue ◽  
Vertical Force ◽  
Test Models ◽  
Isochromatic Fringes ◽  
Mucosal Thickness ◽  
Photoelastic Analysis ◽  
Photoelastic Stress ◽  
The Right ◽  
Mandibular Overdenture

Introduction: The aim of this study was to evaluate the effect of different heights of attachment and mucosa thicknesses on the stress distribution of two implant-retained mandibular overdenture designs under loading using the photoelastic stress analysis method. Materials and methods: Six photoelastic models of an edentulous mandibula were fabricated with two solitary implants that were placed in the canine regions. The attachment systems studied were ball and locator stud attachments. Both the ball and locator groups included three models that had different residual ridge heights so as to provide different mucosa thicknesses (1 mm–1 mm, 1 mm–2 mm, 1 mm–4 mm). A static vertical force of 135 N was applied unilaterally (each on the right then the left side) to the central fossa of the first molars. Models were positioned in the field of a circular polariscope to observe the distribution of isochromatic fringes around the implants and the interimplant areas under loading. The photoelastic stress fringes were monitored and recorded photographically. Results: The ball attachment groups showed higher stress values than did the locator groups under loading. Both attachment systems produced the lowest stress values in stimulated 1 mm–1 mm mucosa thickness models. The models with 1 mm–2 mm mucosa thicknesses showed higher stress values than did other models for both attachment systems. The highest stress value observed around both attachment systems was the moderate level in all test models. Conclusion: In different height mucosa thicknesses, locator attachment models distributed the load to the other side of the implant and its surrounding tissue, whereas the ball attachment did not. Regardless of mucosal thickness and attachment type, the implant on the loading side was subjected to the highest stress concentration.

Photoelastic Analysis on Different Retention Methods of Implant-Supported Prosthesis

2015 ◽  
Vol 41 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Angélica Castro Pimentel ◽  
Marcello Roberto Manzi ◽  
Cristiane Ibanhês Polo ◽  
Claudio Luiz Sendyk ◽  
Maria da Graça Naclério-Homem ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Axial Load ◽  
Testing Machine ◽  
Compressive Load ◽  
Lower Intensity ◽  
Photoelasticity Method ◽  
Universal Testing ◽  
Isochromatic Fringes ◽  
Photoelastic Analysis ◽  
Compressive Axial Load

The aim of this study was to evaluate the stress distribution of different retention systems (screwed, cemented, and mixed) in 5-unit implant-supported fixed partial dentures through the photoelasticity method. Twenty standardized titanium suprastructures were manufactured, of which 5 were screw retained, 5 were cement retained, and 10 were mixed (with an alternating sequence of abutments), each supported by 5 external hexagon (4.0 mm × 11.5 mm) implants. A circular polariscope was used, and an axial compressive load of 100 N was applied on a universal testing machine. The results were photographed and qualitatively analyzed. We observed the formation of isochromatic fringes as a result of the stresses generated around the implant after installation of the different suprastructures and after the application of a compressive axial load of 100 N. We conclude that a lack of passive adaptation was observed in all suprastructures with the formation of low-magnitude stress in some implants. When cemented and mixed suprastructures were subjected to a compressive load, they displayed lower levels of stress distribution and lower intensity fringes compared to the screwed prosthesis.

Photoelastic Analysis of Stress Distribution With Different Implant Systems

2014 ◽  
Vol 40 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Eduardo Piza Pellizzer ◽  
Rafael Imai Carli ◽  
Rosse Mary Falcón-Antenucci ◽  
Fellippo Ramos Verri ◽  
Marcelo Coelho Goiato ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Testing Machine ◽  
Load Direction ◽  
Mass Model ◽  
Load Model ◽  
Universal Testing ◽  
Isochromatic Fringes ◽  
Photoelastic Analysis ◽  
Oblique Load

The aim of this study was to evaluate stress distribution with different implant systems through photoelasticity. Five models were fabricated with photoelastic resin PL-2. Each model was composed of a block of photoelastic resin (10 × 40 × 45 mm) with an implant and a healing abutment: model 1, internal hexagon implant (4.0 × 10 mm; Conect AR, Conexão, São Paulo, Brazil); model 2, Morse taper/internal octagon implant (4.1 × 10 mm; Standard, Straumann ITI, Andover, Mass); model 3, Morse taper implant (4.0 × 10 mm; AR Morse, Conexão); model 4, locking taper implant (4.0 × 11 mm; Bicon, Boston, Mass); model 5, external hexagon implant (4.0 × 10 mm; Master Screw, Conexão). Axial and oblique load (45°) of 150 N were applied by a universal testing machine (EMIC-DL 3000), and a circular polariscope was used to visualize the stress. The results were photographed and analyzed qualitatively using Adobe Photoshop software. For the axial load, the greatest stress concentration was exhibited in the cervical and apical thirds. However, the highest number of isochromatic fringes was observed in the implant apex and in the cervical adjacent to the load direction in all models for the oblique load. Model 2 (Morse taper, internal octagon, Straumann ITI) presented the lowest stress concentration, while model 5 (external hexagon, Master Screw, Conexão) exhibited the greatest stress. It was concluded that Morse taper implants presented a more favorable stress distribution among the test groups. The external hexagon implant showed the highest stress concentration. Oblique load generated the highest stress in all models analyzed.

scholarly journals Photoelastic analysis of stress distribution on parallel and angled implants after installation of fixed prostheses

2004 ◽  
Vol 18 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Cristiane Ueda ◽  
Roberto Adrian Markarian ◽  
Cláudio Luiz Sendyk ◽  
Dalva Cruz Laganá
Keyword(s):  
Stress Distribution ◽  
Apical Region ◽  
Axial Loads ◽  
Bone Morphology ◽  
Prosthetic Rehabilitation ◽  
Implant Placement ◽  
Isochromatic Fringes ◽  
Fixed Prosthesis ◽  
Photoelastic Analysis ◽  
Surrounding Bone

The longevity of implant-supported prosthetic rehabilitation depends largely on how the masticatory forces are transferred to the implants and surrounding bone. Anatomical conditions, bone morphology and aesthetics usually dictate implant placement in less than ideal positions for prosthetic rehabilitation and sometimes it is possible to find them with different inclinations. The purpose of this paper was to compare, through photoelastic analysis, the stress distribution in a fixed prosthesis with 3 parallel implants, to the stress distribution in the same prosthesis in the existence of an angled central implant. Two photoelastic resin models were made and a polariscope was used in the visualization of isochromatic fringes formed in the models when axial loads of 2 kg, 5 kg and 10 kg were applied to a unique central point of the prosthesis. The presence of inducted tensions (preloads) was observed in the models after applying torque to the retention screws. Preloads were intensified with the incidence of occlusal forces. In the parallel implants, the force dissipation followed the long axis. The angled implant had a smaller quantity of fringes and the stresses were located mostly around the apical region of the lateral implants.

Effects of Lingualized and Linear Occlusion Schemes on the Stress Distribution of an Implant Retained Overdenture Using Finite Element Analysis

2015 ◽  
Author(s):  
Md Abu Hasan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Alveolar Bone ◽  
High Stress ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Molar Teeth ◽  
The Right ◽  
Mandibular Overdenture

This study compares the effects of lingualized and linear occlusion schemes on the stress distribution of an implant retained mandibular overdenture (IRO) using finite element analysis (FEA). A high fidelity solid model of mandibular overdenture incorporating cusps and fossae of occlusal surface with two anterior implants in the canine regions and residual ridge support in the posterior region of the alveolar bone was modeled in SolidWorks and imported to ANSYS for stress analysis. The load was applied vertically to the central grooves and buccal cusp tips of the premolars and molar teeth for the lingualized and linear occlusion respectively. The loading magnitudes were 200 N on the premolars and 200 N on the molar teeth with multiple contact locations. The results show that the linear occlusion scheme generated higher stress in the implants and the prosthetic bar than the lingualized occlusion. The locations of high stress concentrations were the neck of the implants and the implant-prosthetic bar intersection for both the occlusion schemes. However, in the cortical bone lingualized occlusion loading scheme generated higher stress (max principal stress) than the linear one suggesting possibility of greater bone loss. The results of this study could be used to comprehend the stress distribution in the denture teeth, base, bone-implant interface and surrounding bone for the two occlusion concepts and may be of help to the clinicians in choosing the right scheme for the edentulous patients.

Photoelastic Stress Distribution Produced by Different Retention Systems for a Single-Implant Mandibular Overdenture

2015 ◽  
Vol 24 (7) ◽  
pp. 538-542 ◽  
Author(s):  
João Francisco Machado Nascimento ◽  
Fábio Afrânio Aguiar-Júnior ◽  
Túlio Eduardo Nogueira ◽  
Renata Cristina Silveira Rodrigues ◽  
Cláudio Rodrigues Leles
Keyword(s):  
Stress Distribution ◽  
Photoelastic Stress ◽  
Mandibular Overdenture ◽  
Single Implant

OSTEOMYELITIS KRONIS MANDIBULA PASCA EKSTRAKSI GIGI DISERTAI BELL’S PALSY

2019 ◽  
Vol 6 ◽  
pp. 52
Author(s):  
Yayun Siti Rochmah
Keyword(s):  
Facial Nerve ◽  
Panoramic Radiograph ◽  
Surrounding Tissue ◽  
Facial Nerve Paralysis ◽  
Muscle Paralysis ◽  
Nerve Paralysis ◽  
The Right ◽  
Spread Of Infection ◽  
Nerve System ◽  
Intravenous Ketorolac

Background: Chronic osteomyelitis mandibula is one of the complications from dental extraction. Inadequate wound handling can have an impact on the spread of infection in the surrounding tissue like nerve which results in facial nerve paralysis. The purpose is to present a rare case that facilitative nerve paralysis as a result of the spread of osteomyelitis infectionCase Management: A 69 years old woman with chief complains numbness onher lips accompanied by pus out beside the lower teeth. No sistemic disease. Panoramic radiograph showed abnormal bone-like sequester. Extraoral examination appeared the bluish color on the right cheek and there was right facial muscle paralysis. Debridement, sequesterectomy by general anesthesia and medication using ceftriaxone intravenous, ketorolac injection, multivitamin, and corticosteroid, physiotherapy for facial nerve paralyze, also.Discussion: Pathogenesis mandibular osteomyelitis involves contiguous spreadfrom an odontogenic focus infection. The bacteria produce an exotoxin, which, while unable to cross the blood-brain barrier, can have deleterious effects on thePeripheral Nerve System (Fasialis Nerve) in up to 75% of cases, with the severity of presentation correlating with the severity of the infection.Conclusion: Chronic mandibular osteomyelitis can spread the infection to around another anatomy oral cavity like facials nerves.

scholarly journals Breast Angiosarcoma with a Preoperative Diagnosis of Late Recurrence of Breast Cancer: A Case Report

2021 ◽  
pp. 604-609
Author(s):  
Rika Kouhashi ◽  
Shinichiro Kashiwagi ◽  
Yuka Asano ◽  
Tamami Morisaki ◽  
Sae Ishihara ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Preoperative Diagnosis ◽  
Vascular Endothelial Cells ◽  
Interstitial Fibrosis ◽  
Late Recurrence ◽  
Breast Conserving Surgery ◽  
Surrounding Tissue ◽  
Axillary Lymph ◽  
Elevated Lesion ◽  
The Right

Angiosarcoma is a malignant mesenchymal tumor characterized by the presence of vascular endothelial cells. Although rare, angiosarcoma developing in the mammary glands has a poor prognosis. We report a case of breast angiosarcoma with a preoperative diagnosis of late recurrence of breast cancer. A 78-year-old woman noticed a tumor in her right breast and visited our hospital. The patient had undergone breast-conserving surgery and axillary lymph node dissection from the right breast 12 years before the visit. The tumor was diagnosed as T4bN0M0, stage IIIB. Anastrozole was administered as postoperative adjuvant therapy for 5 years; the patient also received 50-Gy whole-breast radiation therapy after surgery. Physical examination during her visit revealed an elevated lesion with blue purpura around the nipple in the right breast. We performed breast ultrasound and detected a well-defined 19.6 × 16.4 × 10.7 mm hypoechoic tumor in the left subareolar area. The patient underwent core needle biopsy (CNB). Based on the CNB specimen findings, she was suspected to experience late local recurrence after surgery. Therefore, she underwent total mastectomy after breast-conserving surgery. A dark-red tumor sized 18 × 12 mm was found in a specimen from the nipple. The pathological diagnosis of the specimen revealed short spindle-shaped tumor cells with strong nuclear pleomorphism and a significant interstitial fibrosis. Immunohistochemistry using D2-40 and CD31 antibodies showed irregular luminal proliferation at the anastomosis, infiltration into the surrounding tissue, and massive necrosis, thereby leading to the diagnosis of breast angiosarcoma. We have reported a case of breast angiosarcoma with a preoperative diagnosis of late recurrence of breast cancer.

PHOTOELASTIC ANALYSIS OF STRESS DISTRIBUTION ON THE TIBIOFEMORAL JOINT AFTER MENISCECTOMY

Orthopedics ◽  
1992 ◽  
Vol 15 (12) ◽  
pp. 1445-1450
Author(s):  
Joo-Chul Ihn ◽  
Myun-Whan Ahn ◽  
Dae-Mang Kim
Keyword(s):  
Stress Distribution ◽  
Tibiofemoral Joint ◽  
Photoelastic Analysis

Pilot study comparing the photoelastic stress distribution for four endodontic post systems

1996 ◽  
Vol 23 (10) ◽  
pp. 679-685 ◽  
Author(s):  
B. I. COHEN ◽  
S. CONDOS ◽  
B. L. MUSIKANT ◽  
A. S. DEUTSCH
Keyword(s):  
Pilot Study ◽  
Stress Distribution ◽  
Photoelastic Stress

scholarly journals Characteristics and Dynamics of Full Arch Distalization Using Transpalatal Arches with Midpalatal and Interradicular Miniscrews as Temporary Anchorage Devices: A Preliminary Finite Element Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Mashallah Khanehmasjedi ◽  
Sepideh Bagheri ◽  
Vahid Rakhshan ◽  
Mojtaba Hasani
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Orthodontic Appliances ◽  
Element Analysis ◽  
Midpalatal Suture ◽  
Second Molar ◽  
Bodily Movement ◽  
Anterior Teeth ◽  
The Right

Introduction. Miniscrews have proved quite effective in fixed orthodontic treatment. They can be placed in areas like palatal interradicular zones or midpalatal suture. Despite the value of these methods and their ever-increasing use, their characteristics are not assessed before when implanted in palatal interradicular areas or in the midpalatal suture. We aimed to assess, for the first time, the dynamics of full arch distalization using such miniscrews. Methods. A 3D model of maxilla with all permanent dentition was created from a CT scan volume. Tissues were segmented and differentiated. Afterward, miniscrews and appliances were designed, and the whole model was registered within a finite element analysis software by assigning proper mechanical properties to tissues and orthodontic appliances. The full arches were distalized using transpalatal arches with miniscrews as anchorage devices (in two different models). The extents of stresses and patterns of movements of various elements (teeth, miniscrews, appliances, tissues) were estimated. Results and Conclusions. Comparing the two models, it is obvious that in both models, the stress distribution is the highest in the TPA arms and the head of the miniscrew where the spring is connected. In comparison with the displacement in the X-axis, the “mesial in” rotation is seen in the first molar of both models. But there is one exception and that is the “mesial out” rotation of the right second molar. In all measurements, the amount of movement in Model 2 (with palatal interradicular miniscrews) is more than that in Model 1 (with midpalatal miniscrew). In the Y-axis, more tipping is seen in Model 2, especially the anterior teeth (detorque) and the first molar, but in Model 1, bodily movement of the first molar is more evident. Along the Z-axis, the mesial intrusion of the first molar and the distal extrusion of this tooth can be seen in both models. Again, the displacement values are higher in the second model (with interradicular miniscrews). In comparison with micromotion and stress distribution of miniscrews, in Model 1, maximum stress and micromotion is observed at the head of the miniscrew where it is attached to the spring. Of course, this amount of micromotion increases over time. The same is true for Model 2, but with a lower micromotion. As for the amount of stress, the stress distribution in both miniscrews of both models is almost uniform and rather severe.

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