ORCID Profile
0000-0002-6691-5428
Current Organisation
Chiang Mai University
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Publisher: Trans Tech Publications, Ltd.
Date: 07-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.268-270.853
Abstract: Bioceramics have rapidly emerged as one of major biomaterials in modern biomedical applications because of its outstanding biocompatibility. However, one drawback is its low tensile strength and fracture toughness due to brittleness and inherent microstructural defects, which to a certain extent prevents the ceramics from fully replacing metals used as load-bearing prostheses. This paper aims to model the crack initiation and propagation in ceramic fixed partial denture, namely dental bridge, by using two recently developed methods namely continuum-to-discrete element method (CDEM) in ELFEN and extended finite element methods (XFEM) in ABAQUS. Unlike most existing studies that typically required prescriptions of initial cracks, these two new approaches will model crack initiation and propagation automatically. They are applied to a typical prosthodontic ex le, thereby demonstrating their applicability and effectiveness in biomedical applications.
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.PROSDENT.2022.05.003
Abstract: Preserving teeth with radicular cracks with or without a periodontal pocket is an alternative to extraction. However, an effective protocol for the restoration of radicular cracks is lacking. The purpose of this study was to examine the composite resin core level and periodontal pocket depth effects on stress distribution, maximum von Mises stress, and crack propagation in endodontically treated teeth by using the extended finite element (FE) method. Four 3-dimensional models of a cracked endodontically treated mandibular first molar were constructed: PP2C2 (periodontal pocket depth, 2 mm composite resin core level, 2 mm below the canal orifice level) PP2C4 (periodontal pocket depth, 2 mm composite resin core level, 2 mm below the crack level) PP4C2 (periodontal pocket depth, 4 mm composite resin core level, 2 mm below the canal orifice level) and PP4C4 (periodontal pocket depth, 4 mm composite resin core level, 2 mm below the crack level). The crack initiation was at the same level in all models. A static 700-N load was applied to the models in a vertical direction. The highest stress in dentin was observed in PP2C2, whereas PP2C4 exhibited the lowest stress and least crack propagation. Stress was high in the dentin and supporting bone. No reduction in crack propagation was observed in the PP4 models, regardless of the composite resin core level. The periodontal pocket depth (2 mm and 4 mm) and composite resin core level (2 mm below the crack level and 2 mm below the canal orifice level) affected stress concentration in dentin, resulting in different patterns of crack propagation in the FE models.
Publisher: Wiley
Date: 26-12-2018
DOI: 10.1002/CRE2.152
Publisher: Elsevier BV
Date: 08-2011
Publisher: Trans Tech Publications, Ltd.
Date: 08-2009
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.79-82.2167
Abstract: This paper aims at providing a preliminary understanding in biomechanics with respect to the effect of FPC dental implants on bone remodelling. 2D multi-scale finite element models are created for a typical dental implantation setting. Under a certain mastication force ( N), a global response from a macro-scale model (without considering coated surface morphology details) is first obtained and then it is transferred to the micro-scale models (with coated surface morphology details and various particle sizes) for micro-scale analysis. A strain energy density (SED) obtained from 2D micro-scale Finite Element Analysis (FEA) is used as a mechanical stimulus to determine the bone remodeling in term of the change in apparent bone densities for cancellous and cortical bones. The change in bone densities is examined as a result of bone remodelling activities over a period of 48 months.
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.JMBBM.2012.08.019
Abstract: Rapid and stable osseointegration signifies a major concern in design of implantable prostheses, which stimulates continuous development of new implant materials and structures. This study aims to develop a graded configuration of a bead article coated porous surface for implants by exploring how its micromechanical features determine osseointegration through multiscale modeling and remodeling techniques. A typical dental implantation setting was exemplified for investigation by using the remodeling parameters determined from a systematic review of bone-implant-contact (BIC) ratio published in literature. The global responses of a macroscale model were obtained through 48 month remodeling simulation, which forms the basis for the 27 microscopic models created with different particle gradients ranging from 30 to 70μm. The osseointegration responses are evaluated in terms of the BIC ratio and the averaged 10% peak Tresca shear stress (PTS). Within the s ling designs considered, the configuration with 50-30-30μm particle sizes provides the best outcome, counting 20% more BIC ratio and 0.17MPa less PTS compared with the worst case scenario, also outperforming the best uniform morphology of 70μm particles. Furthermore, the response surface method (RSM) was utilized to formulate the bone remodeling responses in terms of gradient parameters across three layers. Gradient 30.0-30.0-32.1 is found an optimal gradient for BIC ratio, and 70-45.4-40.8 the best for the minimum PTS. The multiobjective optimization was finally performed to simultaneously maximize BIC ratio and minimize PTS for achieving the best possible overall outcome. Due to strong competition between these two design objectives, a Pareto front is generated. To make a proper trade-off, the minimum distance selection criterion is considered and the gradient of 37.1-70.0-67.7 appears an optimal solution. This study provides a novel surface configuration and design methodology for in idual patient that allow optimizing topographical gradient for a desirable patient-specific biomechanical environment to promote osseointegration.
Publisher: Trans Tech Publications Ltd.
Date: 09-02-2008
Publisher: Elsevier BV
Date: 09-2010
DOI: 10.1016/J.BIOMATERIALS.2010.05.077
Abstract: This paper aims to establish a relationship between the surface morphology induced micromechanics and bone remodeling responses to a solid bead coated porous implant and further to develop a multiobjective optimization framework for the coating design of biomaterials. Multiscale modeling and remodeling techniques were developed, where a macroscopic analysis was initially performed to generate a global response to enable a microscopic analysis. The bone remodeling responses of the microscopic models (with a specific surface morphology) were evaluated in terms of the average apparent density developed in the peri-implant region. To explore the proposed multiscale analysis and design methods, a typical dental implantation setting is exemplified in this study. The response surface method (RSM) was utilized to relate the major implant coating parameters to the bone responses. It is found that increasing the volume fraction of the coating beads articles results in a greater bone density, whereas increasing bead article size does not significantly affect the bone's responses. Several different multiobjective optimization schemes were adopted to optimize the coated bead size and volume fraction, which reveal that the optimal design parameters of particle diameter and volume fraction are 100 microm--35% and 38 microm--17.5% for the cortical and cancellous bones respectively, agreeing with clinical data. To maximize the implant/bone interfacial stability, specific surface coating designs for particular locations are recommended.
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.ACTBIO.2013.05.009
Abstract: Effective and reliable clinical uses of dental ceramics necessitate an insightful analysis of the fracture behaviour under critical conditions. To better understand failure characteristics of porcelain veneered to zirconia core ceramic structures, thermally induced cracking during the cooling phase of fabrication is studied here by using the extended finite element method (XFEM). In this study, a transient thermal analysis of cooling is conducted first to determine the temperature distributions. The time-dependent temperature field is then imported to the XFEM model for viscoelastic thermomechanical analysis, which predicts thermally induced damage and cracking at different time steps. Temperature-dependent material properties are used in both transient thermal and thermomechanical analyses. Three typical ceramic structures are considered in this paper, namely bi-layered spheres, squat cylinders and dental crowns with thickness ratios of either 1:2 or 1:1. The XFEM fracture patterns exhibit good agreement with clinical observation and the in vitro experimental results obtained from scanning electron microscopy characterization. The study reveals that fast cooling can lead to thermal fracture of these different bi-layered ceramic structures, and cooling rate (in terms of heat transfer coefficient) plays a critical role in crack initiation and propagation. By exploring different cooling rates, the heat transfer coefficient thresholds of fracture are determined for different structures, which are of clear clinical implication.
Publisher: Japan Prosthodontic Society
Date: 2018
DOI: 10.1016/J.JPOR.2017.05.002
Abstract: To investigate the strains around mini-dental implants (MDIs) and retromolar edentulous areas when using different numbers of MDIs in order to retain mandibular overdentures. Four different prosthetic situations were fabricated on an edentulous mandibular model including a complete denture (CD), and three overdentures, retained by four, three or two MDIs in the interforaminal region with retentive attachments. A static load of 200N was applied on the posterior teeth of the dentures under bilateral or unilateral loading conditions. The strains at the mesial and distal of the MDIs and the retromolar edentulous ridges were measured using twelve strain gauges. Comparisons of the mean microstrains among all strain gauges in all situations were analyzed. The strain distribution determined during bilateral loading experienced a symmetrical distribution while during unilateral loading, the recorded strains tended to change from compressive strains on the loaded side to tensile strains. Overall, the number of MDIs was found to be passively correlated to the generated compressive strain. The highest strains were recorded in the four MDIs followed by three, two MDIs retained overdenture and CD situations, respectively. The highest strain was found around the terminal MDI. The use of a low number of MDIs tends to produce low strain values in the retromolar denture-bearing area and around the terminal MDIs during posterior loadings. However, when using a high number of MDIs, the overdenture tends to have more stability during function.
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.ARCHORALBIO.2012.05.001
Abstract: To explore the possible role of functional stress in driving continuous post-eruptive emergence of teeth. A two dimensional finite element analysis model was established with a single mandibular premolar subjected to sagittal bending. Equivalent strain was charted for the inner and outer surfaces of the lamina dura, because bone deposition and resorption of this structure is confined to surface osteoblasts and osteoclasts. Bone disuse resorption was assumed to take place at equivalent strain values below 0.0008, while deposition was above 0.002. Strain in the periodontal ligament and principal stress throughout the model were also characterized. Strain analysis indicated bone maintenance for the lamina dura throughout most of the root length, but in both the apical and upper root regions, resorption was predicted for the outer surface, and bone deposition was predicted for the inner surface of the lamina dura. Strain in the periodontal ligament varied little with the exception of a marked increase close to the crown. Principal stress analysis revealed compression of the lower model border, with areas of increasing tension towards the upper model border. Strain from functional forces may continuously drive post-eruptive emergence of teeth through bony remodelling of the lamina dura, lifting teeth by both raising the apical lamina dura, and narrowing the upper root space to accommodate tapering root form. Such strain-driven bone turnover may contribute to pre-eruptive movement of teeth.
Publisher: IOP Publishing
Date: 06-2010
Publisher: Wiley
Date: 31-10-2023
DOI: 10.1111/JOPR.13776
Publisher: American Scientific Publishers
Date: 03-2011
Publisher: Wiley
Date: 16-05-2022
DOI: 10.1111/JOPR.13530
Abstract: The purpose was to investigate stress distribution among 4 different customized abutment types: titanium abutment (Ti), titanium hybrid‐abutment‐crown (Ti‐Hybrid), zirconia abutment with titanium base (Zir‐TiBase), and zirconia hybrid‐abutment‐crown with titanium base (Zir‐Hybrid‐TiBase). To achieve this purpose, 4 types of abutment configurations were simulated. A static load of 200 N (vertical) and 100 N (oblique) were applied to the models. The volume average, maximum, and stress distribution of von Mises stress, including percentage difference, were analyzed with 3D finite element analysis. According to the volume average von Mises stress, the Ti and Zir‐TiBase comparison group showed that the Zir‐TiBase group dominantly generated the higher value at Ti‐base (22.57 MPa) and screw (17.68 MPa). To evaluate the effect of the hybrid‐abutment‐crown on volume average von Mises stress by comparing the Ti‐Hybrid and Zir‐Hybrid‐TiBase groups, it was revealed that the combination of abutment and crown in the Ti‐Hybrid group generated the worst stress concentration at the screw (12.42 MPa), while in the Zir‐Hybrid‐TiBase group presented stress concentration at the implant (8.90 MPa). A titanium base improved stress distribution at implant in zirconia abutment with titanium base by absorbing stress itself. Customized titanium hybrid‐abutment‐crown and zirconia hybrid‐abutment‐crown with titanium base created concentrated stress at screw and implant respectively. Both abutment types should be cautiously used and maintenanced regularly.
Publisher: Springer Science and Business Media LLC
Date: 11-09-2015
DOI: 10.1007/S10237-014-0612-6
Abstract: This paper explores the biomechanics and associated bone remodeling responses of two different abutment configurations, namely implant-implant-supported versus tooth-implant-supported fixed partial dentures. Two 3D finite element analysis models are created based upon computerized tomography data. The strain energy density induced by occlusal loading is used as a mechanical stimulus for driving the bone remodeling. To measure osseointegration and stability during healing, a resonance frequency analysis is conducted. At the second premolar peri-implant region, overloading resorption around the neck of implant is identified in both the models over the first 12 months. Stress-shielding around the edentulous region is also observed in both the models with a greater resorption rate found in the implant-implant case. The remodeling and resonance frequency analyses reveal that the tooth-implant scheme offers a higher degree of osseointegration. The remodeling procedure is expected to provide prosthodontists with a modeling tool to assess possible long-term clinical outcomes.
Publisher: Hindawi Limited
Date: 11-03-2022
DOI: 10.1155/2022/2416888
Abstract: Introduction. The removable partial denture (RPD) components, especially the retentive arm, play a major role in the loading characteristic on supporting structures. Objective. To evaluate and compare the effect of different clasp designs on the stress distribution pattern, maximum von Mises stress, and average hydrostatic pressure on abutment teeth, as well as edentulous ridges, mini dental implants (MDIs), and peri-implant bone between the conventional removable partial denture (CRPD) and mini dental implant-assisted distal extension removable partial denture (IARPD) using a three-dimensional finite element analysis (3D FEA). Materials and Methods. 3D FEA models of mandibular arches, with and without bilateral MDI at the second molar areas, and Kennedy class I RPD frameworks, with RPA, RPI, Akers, and no clasp component, were generated. A total of 200 N vertical load was bilaterally applied on both sides of distal extension areas, and the stress was analyzed by 3D FEA. Results. The stress concentration of IARPD with RPI clasp design was located more lingually on abutment teeth, MDI, and peri-implant bone, while the other designs were observed distally on the supporting structures. The maximum von Mises stress on the abutment root surface was decreased when the RPDs were assisted with MDIs. The CRPD and IARPD with the Akers clasp design showed the highest von Mises stress followed by the designs with RPA and RPI clasp, respectively. The average hydrostatic pressure in each group was in approximation. Conclusion. The placement of MDIs on distal extension ridges helps to reduce the stress concentration on denture supporting structures. The maximum von Mises stress is affected by the different designs of clasp components. The CRPD and the IARPD with RPI clasp provide the least stress on supporting structures.
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.DENTAL.2015.11.018
Abstract: This study aimed to in idually quantify the effects of various design parameters, including margin thickness, convergence angle of abutment, and bonding conditions on fracture resistance of resin bonded glass dental crown systems (namely, glass simulated crown). An in vitro experimental test and an in silico computational eXtended Finite Element Method (XFEM) were adopted to explore crack initiation and propagation in glass simulated crown models with the margin thickness ranging from 0.8 to 1.2mm, convergence angle from 6° to 12°, and three different bonding conditions, namely non-bonded (NB), partially bonded (PB), fully bonded (FB). The XFEM modeling results of cracking initiation loads and subsequent growth in the glass simulated crown models were correlated with the experimental results. It was found that the margin thickness has a more significant effect on the fracture resistance than the convergence angle. The adhesively bonded state has the highest fracture resistance among these three different bonding conditions. Crowns with thicker margins, smaller convergence angle and fully bonded are recommended for increasing fracture resistance of all-ceramic crowns. This numerical modeling study, supported by the experimental tests, provides more thorough mechanical insight into the role of margin design parameters, thereby forming a novel basis for clinical guidance as to preparation of tapered abutments for all-ceramic dental crowns.
Publisher: Hindawi Limited
Date: 04-05-2021
DOI: 10.1155/2021/6688521
Abstract: Purpose. To investigate the effect of minidental implant location on strain distributions transmitted to tooth abutments and dental minidental implants under mandibular distal extension removable partial denture. Materials and Methods. A mandibular Kennedy Class I distal extension model missing teeth 35–37 and 45–47 was constructed. Six dental mini-implants were placed at positions A, B, and C, where position A was 6.5 mm distal to the abutment teeth with 5 mm between each position. Fourteen uniaxial strain gauges were bonded on the model at the region of dental mini-implant and abutment (first premolar). Four groups were designated according to the location of the mini-implants. A load of 150 N and 200 N was applied using an Instron testing machine. Loadings consisted of bilateral and unilateral loading. Comparisons of the mean microstrains among all strain gauges in all situations were analyzed. Results. Variation in mini-implant locations induced local strains in different areas. Strains at the tooth abutment were significantly decreased in the group in which implants were placed mesially. Strains around the mini-implants showed different patterns when loaded with different loading conditions. The group in which implants were placed distally showed the lowest strains compared to other groups. Conclusion. Mesially placed mini-implants showed the lowest strain around abutment teeth, while a distally-placed mini-implants presented the lowest strain around mini-implants themselves. Under favorable biting force, mini-implant is an option to assist mandibular distal extension removable partial denture. Mesially placed mini-implants are recommended when the abutment has periodontally compromised conditions and a distally placed mini-implant when periodontal conditions are stable.
Publisher: Hindawi Limited
Date: 26-03-2022
DOI: 10.1155/2022/4825177
Abstract: Purpose. To investigate effects of number and location on patterns of von Mises stress distribution and volume average stress on abutment tooth, edentulous ridge, mini dental implant, and surrounding bone of mini dental implant-assisted mandibular Kennedy class I removable partial denture. Materials and Methods. Eight three-dimensional finite element models of mandibular Kennedy class I with different numbers and locations of mini dental implants were constructed. Mini dental implants were generated in the area of second premolar, first molar, and second molar, respectively. A static load of 400 N was applied on all models. The von Mises stress and volumetric average stress were calculated by three-dimensional finite element analysis. Result. The minimum volumetric average stress of abutment tooth was found in the model, where there was one mini dental implant at the second molar position and 2 mini dental implants at first molar and second molar positions. The model with three mini dental implants had reduced volumetric average stress of abutment tooth, which was not different from the model with two mini dental implants. However, the minimum volumetric average stress of mini dental implant and surrounding bone were found when three mini dental implants were applied, followed by two and one mini dental implants, respectively. Conclusion. Placing at least one mini dental implant at a second molar position can help reduce stress transferred to the abutment tooth. Stresses around each implant and surrounding bone reduced with increased numbers of mini dental implants.
No related grants have been discovered for Chaiy Rungsiyakull.