Medicine and Health Sciences Commons^™

Analysis Of Stresses In Mandible And Skull Under Angular Impact, Dr. Shobha E S, Dr. Suresh Nagesh, Dr. H P. Raghuveer, Mr. Vinay K. S

Innovative Research Publications IRP India

Finite element analysis has gained a significant attention in the field of biomechanics. The versatility of finite element analysis is the major reason behind its implementation and adoption has made the study of biomechanics much easier and simpler. FEA, as a tool has helped in analyzing the various organs in human body in different loading conditions. Be it Orthopedic,Maxillofacial fractures,Orthodontics, Prosthodontics, hemodynamics, it is finding its applications in all areas of biomechanics. In this paper, one such study has been carried out to understand the behavior of skull and mandible under inclined impacts. Skull is one of the highly complicated …

Effect Of Post Materials On The Biomechanical Behaviour Of Endodontically Treated Tooth., Ahmed A. Madfa

Ahmed A. Madfa

Objectives: To study the stress distributions in maxillary central incisor restored with Ni-Cr custom-made, gold custom-made, prefabricated titanium and prefabricated glass fibre dental posts subjected to oblique occlusal load at 100 N. Materials and Methods: Four three dimensional finite element models of a maxillary central incisor restored with Ni-Cr (Model I), gold custom-made (Model II), prefabricated titanium (Model III) and prefabricated glass fibre (Model IV) dental posts were constructed and oblique loading of 100 N was applied. Stress analysing at the along the centre of the post and post-surrounding structure interfaces were computed. Results: The result of this study indicates …

Alumina Ceramic For Dental Applications: A Review Article., Ahmed A. Madfa

Ahmed A. Madfa

Alumina has received considerable attention and has been historically wellaccepted as biomaterials for dental and medical applications. This article reviews the applications of this material in dentistry. It presents a brief history, dental applications and methods for improving the mechanical properties of aluminabased materials. It also offers perspectives on recent research aimed at the further development of alumina for clinical uses, at their evaluation and selection, and very importantly, their clinical performance. This article also stated about the Functionally Graded Materials (FGMs) which has been conceived as a new material design approach to improve performance compared to traditional homogeneous and …

Antimicrobial Peptide Coating Of Dental Implants: Biocompatibility Assessment Of Recombinant Human Beta Defensin-2 For Human Cells, Patrick Warnke, Eske Voss, Paul Russo, Sebastien Stephens, Michael Kleine, Hendrik Terheyden, Qin Liu

Qin Liu

Purpose: Artificial materials such as dental implants are at risk of bacterial contamination in the oral cavity. Human beta defensins (HBDs), small cationic antimicrobial peptides that exert a broad-spectrum antibacterial function at epithelial surfaces and within some mesenchymal tissues, could probably help to reduce such contamination. HBDs also have protective immunomodulatory effects and have been reported to promote bone remodeling. The aim of this study, therefore, was to investigate the influence of recombinant HBD-2 on the proliferation and survival of cells in culture.

Materials and Methods: Human mesenchymal stem cells (hMSCs), human osteoblasts, human keratinocytes (control), and the HeLa cancer …

Differentiation Of Dental Pulp Stem Cells Into Islet-Like Aggregates, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

The post-natal dental pulp tissue contains a population of multipotent mesenchymal progenitor cells known as dental pulp stromal/stem cells (DPSCs), with high proliferative potential for self-renewal. In this investigation, we explored the potential of DPSCs to differentiate into pancreatic cell lineage resembling islet-like cell aggregates (ICAs). We isolated, propagated, and characterized DPSCs and demonstrated that these could be differentiated into adipogenic, chondrogenic, and osteogenic lineage upon exposure to an appropriate cocktail of differentiating agents. Using a three-step protocol reported previously by our group, we succeeded in obtaining ICAs from DPSCs. The identity of ICAs was confirmed as islets by dithiozone-positive …

3d-Fe Analysis Of Functionally Graded Structured Dental Posts, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

This study aimed to compare the biomechanical behaviour of functionally graded structured posts (FGSPs) and homogenous-type posts in simulated models of a maxillary central incisor. Two models of FGSPs consisting of a multilayer xTi-yHA composite design, where zirconia and alumina was added as the first layer for models A and B respectively were compared to homogenous zirconia post (model C) and a titanium post (model D). The amount of Ti and HA in the FGSP models was varied in gradations. 3D-FEA was performed on all models and stress distributions were investigated along the dental post. In addition, interface stresses between …

Inherent Differential Propensity Of Dental Pulp Stem Cells Derived From Human Deciduous And Permanent Teeth, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Introduction: Lately, several new stem cell sources and their effective isolation have been reported that claim to have potential for therapeutic applications. However, it is not yet clear which type of stem cell sources are most potent and best for targeted therapy. Lack of understanding of nature of these cells and their lineage-specific propensity might hinder their full potential. Therefore, understanding the gene expression profile that indicates their lineage-specific proclivity is fundamental to the development of successful cell-based therapies. Methods: We compared proliferation rate, gene expression profile, and lineage-specific propensity of stem cells derived from human deciduous (SCD) and permanent …

Thermo-Mechanical Stress In Multilayered Dental Post Due To Temperature Gradient, Ahmed A. Madfa

Ahmed A. Madfa

Objective: To analyse thermo-mechanical stress in endodontically treated teeth restored with Multilayered Structured Dental Posts (MSDPs) under cold and hot conditions using Finite Element Analysis (FEM). Methods: Three MSDPs of multilayer design of xTi-yHA composition added to a zirconia layer (model A), an alumina layer (model B) and a titanium layer (model C) were compared with zirconia (model D) and titanium (model E) posts. The fractions of Ti and HA was varied gradually. Changes in temperature of an endodontically restored tooth model were calculated as a result of hot and cold response. The resulting thermo-mechanical stresses were analysed and compared …

Cutting Efficiency Of Dental Burs-A Pilot Study, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Objectives: This study aim to evaluate the cutting efficiency of tungsten carbide burs (TC) and rotary diamond instruments by measuring their rake angle and visual examination of their cutting surfaces respectively, using scanning electron microscopy (SEM). Materials and Method: 60 short and long head pear-shaped TC and 18 round rotary diamond instruments that had been used to prepare < than 5, > than 5 and > than 10 cavities were selected from the 3rd & 4th year dental students, Dental Faculty, University of Malaya. 12 cylindrical and flame rotary diamond instruments were also selected from the 5th year students. The rake angle of TC was …

Push-Out Bond Strength Of Luting Agents To Fibre-Reinforced Post: An In Vitro Study, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

The objective of this study was to investigate the effect of various luting agents on bond strength of fibre-reinforced posts to root canal dentine. 40 extracted single rooted sound premolar teeth were root filled, decoronated and randomly divided into four groups. Fibre posts, Aestheti-Plus (TM) (Bisco,Inc. Schaumburg, IL, USA) were cemented using four luting agents: Group A (control): Elite 1000 Zinc phosphate (GC Corp, Japan), Group B: Calibra (TM) Esthetic Resin Cement (Dentsply Caulk, USA), Group C: RelyX ARC Adhesive Resin (3M ESPE), Group D: RelyX Unicem Aplicap (3M ESPE). Each roots were sliced into 2 discs representing the coronal …

The Ball Mill As A Means Of Investigating The Mechanical Failure Of Dental Materials, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Objective: The main purpose of this paper is to present a new method of predicting clinical performance using mechanical loading in a ball mill. Methods: A series of four experiments (two involving a hybrid composite and one each on orthodontic brackets and bands) is described in which the ball mill was used to subject specimens to mechanical fatigue. Results: A reproducibility study using composite beam specimens showed no significant difference between the Mean Survival Time (MST) in all the three experimental runs (P = 0.42). When subjected to thermal cycling, the MST of the cycled group was 155.0 min compared …