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Mert Eren M, Celebi AT, İçer E, Baykasoğlu C, Mugan A, Yücel T, Yıldız E. Biomechanical Behavior Evaluation of Resin Cement with Different Elastic Modulus on Porcelain Laminate Veneer Restorations Using Micro-CT-Based Finite Element Analysis. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2378. [PMID: 36984260 PMCID: PMC10054651 DOI: 10.3390/ma16062378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/02/2023] [Accepted: 03/10/2023] [Indexed: 06/18/2023]
Abstract
The aim of this study is to evaluate the biomechanical behavior of the porcelain laminate veneer restorations (PLV) of the maxillary central incisor luted with two types of resin cements having different incisal preparations: butt joint and palatal chamfer. Biomechanical analyses were performed using the micro-CT-based finite element models, and von Mises stress and strain values of the PLV, resin cement, adhesive layer, and tooth structure were computed. The PLV with butt joint preparation showed larger stress values than those of restored with palatal chamfer preparation, regardless of the elasticity of the cement and loading conditions. An increase in the elasticity modulus of the resin cement induced slightly larger stresses on the adhesive layer, tooth tissues, and restorative materials. Overall, this study demonstrates the role of the preparation design and luting materials on the mechanical behavior of the PLV restorations and discusses the potential failure mechanisms of the PLV restorations under different loading mechanisms.
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Affiliation(s)
- Meltem Mert Eren
- Department of Restorative Dentistry, Faculty of Dentistry, Altınbas University, 34147 Istanbul, Türkiye
| | - Alper Tunga Celebi
- Institute of Applied Physics, Vienna University of Technology, 1040 Vienna, Austria
| | - Esra İçer
- Department of Informatics, Technische Universität München, 85748 Garching, Germany
| | - Cengiz Baykasoğlu
- Faculty of Engineering Mechanical Engineering Department, Hitit University, 19030 Çorum, Türkiye
| | - Ata Mugan
- Mechanical Engineering Department, Faculty of Mechanical Engineering, Istanbul Technical University, 34437 Istanbul, Türkiye
| | - Taner Yücel
- Department of Restorative Dentistry, Faculty of Dentistry, Istanbul University, 34116 Istanbul, Türkiye
| | - Esra Yıldız
- Department of Restorative Dentistry, Faculty of Dentistry, Istanbul University, 34116 Istanbul, Türkiye
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Dentin Exposure after Tooth Preparation for Laminate Veneers: A Microscopical Analysis to Evaluate the Influence of Operators' Expertise. MATERIALS 2022; 15:ma15051763. [PMID: 35268994 PMCID: PMC8911512 DOI: 10.3390/ma15051763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/02/2022] [Accepted: 02/24/2022] [Indexed: 12/05/2022]
Abstract
Background: To assess the quantity of dentin exposure detected by 3 operators with different clinical expertise for 2 designs of tooth preparation for laminate veneers: window (WI) and butt joint (BJ). Methods: 20 intact maxillary central incisors were collected and then prepared for laminate veneers to a depth of 0.6 mm, with a cervical mini-chamfer finish line of 0.3 mm. Each prepared tooth was analyzed by 3 operators with different expertise: undergraduate student (ST), general practitioner (GP), and prosthodontist (PR), at sight under magnification. Besides descriptive statistics (CI 95%), 2-way ANOVA and Games−Howell tests were used to analyze differences among groups (α = 0.05). Results: The means of percentage and area of detected dentin exposure were WI = 30.48%, 21.57 mm2; BJ = 30.99%, 21.97 mm2; ST/WI = 22.82%, 16.44 mm2; GP/WI = 58.05%, 40.64 mm2; PR/WI = 10.55%, 7.63 mm2; ST/BJ = 28.99%, 20.83 mm2; GP/BJ = 40.56%, 28.32 mm2; PR/BJ = 23.42%, 16.75 mm2. Significant differences were found between ST/WI vs. GP/WI (p = 0.005) and GP/WI vs. PR/WI (p < 0.001). Conclusions: There was no difference in detection of exposed dentin among operators with different expertise for BJ preparation, whereas differences were found between the general practitioner and the other 2 operators in WI. Moreover, the quantity of exposed dentin was not related to different tooth preparation designs.
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Aversa R, Petrescu RV, Petrescu FIT, Perrotta V, Apicella D, Apicella A. Biomechanically Tunable Nano-Silica/P-HEMA Structural Hydrogels for Bone Scaffolding. Bioengineering (Basel) 2021; 8:bioengineering8040045. [PMID: 33916623 PMCID: PMC8065879 DOI: 10.3390/bioengineering8040045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 03/24/2021] [Accepted: 04/02/2021] [Indexed: 11/17/2022] Open
Abstract
Innovative tissue engineering biomimetic hydrogels based on hydrophilic polymers have been investigated for their physical and mechanical properties. 5% to 25% by volume loading PHEMA-nanosilica glassy hybrid samples were equilibrated at 37 °C in aqueous physiological isotonic and hypotonic saline solutions (0.15 and 0.05 M NaCl) simulating two limiting possible compositions of physiological extracellular fluids. The glassy and hydrated hybrid materials were characterized by both dynamo-mechanical properties and equilibrium absorptions in the two physiological-like aqueous solutions. The mechanical and morphological modifications occurring in the samples have been described. The 5% volume nanosilica loading hybrid nanocomposite composition showed mechanical characteristics in the dry and hydrated states that were comparable to those of cortical bone and articular cartilage, respectively, and then chosen for further sorption kinetics characterization. Sorption and swelling kinetics were monitored up to equilibrium. Changes in water activities and osmotic pressures in the water-hybrid systems equilibrated at the two limiting solute molarities of the physiological solutions have been related to the observed anomalous sorption modes using the Flory-Huggins interaction parameter approach. The bulk modulus of the dry and glassy PHEMA-5% nanosilica hybrid at 37 °C has been observed to be comparable with the values of the osmotic pressures generated from the sorption of isotonic and hypotonic solutions. The anomalous sorption modes and swelling rates are coherent with the difference between osmotic swelling pressures and hybrid glassy nano-composite bulk modulus: the lower the differences the higher the swelling rate and equilibrium solution uptakes. Bone tissue engineering benefits of the use of tuneable biomimetic scaffold biomaterials that can be “designed” to act as biocompatible and biomechanically active hybrid interfaces are discussed.
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Affiliation(s)
- Raffaella Aversa
- Advanced Materials Lab, Department of Architecture and Industrial Design, Second University of Naples, Abazia di San Lorenzo, 81031 Aversa, Italy; (R.A.); (V.P.)
| | - Relly Victoria Petrescu
- IFToMM, ARoTMM, Bucharest Polytechnic University, Splaiul Independenței 313, 060042 Bucharest, Romania; (R.V.P.); (F.I.T.P.)
| | - Florian Ion T. Petrescu
- IFToMM, ARoTMM, Bucharest Polytechnic University, Splaiul Independenței 313, 060042 Bucharest, Romania; (R.V.P.); (F.I.T.P.)
| | - Valeria Perrotta
- Advanced Materials Lab, Department of Architecture and Industrial Design, Second University of Naples, Abazia di San Lorenzo, 81031 Aversa, Italy; (R.A.); (V.P.)
| | | | - Antonio Apicella
- Advanced Materials Lab, Department of Architecture and Industrial Design, Second University of Naples, Abazia di San Lorenzo, 81031 Aversa, Italy; (R.A.); (V.P.)
- Correspondence:
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Huang XQ, Hong NR, Zou LY, Wu SY, Li Y. Estimation of stress distribution and risk of failure for maxillary premolar restored by occlusal veneer with different CAD/CAM materials and preparation designs. Clin Oral Investig 2020; 24:3157-3167. [PMID: 32034548 DOI: 10.1007/s00784-019-03190-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 12/26/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVES To compare stress distribution and failure probability in maxillary premolars restored by simple occlusal veneer (SOV) and buccal-occlusal veneer (BOV) with 3 different CAD/CAM materials. MATERIALS AND METHODS A maxillary premolar was digitized by a micro-CT scanner. Three-dimensional dynamic scan data were transformed, and finite element models of 2 different models (SOV and BOV restored teeth) were designed. Three different CAD/CAM materials, including lithium disilicate glass ceramic (LD) IPS e.max CAD, polymer-infiltrated ceramic-network (PICN) Vita Enamic, and resin nano-ceramic (RNC) Lava Ultimate, were designated to both veneers. Maximum principle stresses were determined by applying a 300-N axial load to the occlusal surface. Weibull analyses were performed to calculate the failure probability of the models. RESULTS LD-restored teeth showed the highest stress in the veneer, lowest stress in substrate teeth, and lowest failure probability for the overall system; RNC-restored teeth showed the lowest stress in the veneer, highest stress in substrate teeth, and highest failure probability. No significant differences were found in the cement layer among the different models. No significant differences of stress and failure probability existed between SOV and BOV preparations. CONCLUSIONS CAD/CAM composite resin occlusal veneers bear lower maximum stress than ceramic veneers. Teeth restored by composite veneers are more prone to failure than those restored by ceramic veneers. Additional reduction of the buccal surface did not increase the stress on the occlusal veneer under axial load. CLINICAL RELEVANCE Both occlusal veneers could be used under physiological masticatory force. CAD/CAM glass ceramic was safer than composite resins.
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Affiliation(s)
- Xiao-Qiong Huang
- Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, No. 56 Lingyuan West Road, Guangzhou, 510055, China
| | - Nan-Rui Hong
- Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, No. 56 Lingyuan West Road, Guangzhou, 510055, China
- Department of Stomatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Lei-Yan Zou
- Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, No. 56 Lingyuan West Road, Guangzhou, 510055, China
| | - Shu-Yi Wu
- Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, No. 56 Lingyuan West Road, Guangzhou, 510055, China.
| | - Yan Li
- Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, No. 56 Lingyuan West Road, Guangzhou, 510055, China.
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Tsouknidas A, Karaoglani E, Michailidis N, Kugiumtzis D, Pissiotis A, Michalakis K. Influence of Preparation Depth and Design on Stress Distribution in Maxillary Central Incisors Restored with Ceramic Veneers: A 3D Finite Element Analysis. J Prosthodont 2019; 29:151-160. [PMID: 31663223 DOI: 10.1111/jopr.13121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2019] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To evaluate the influence of different preparation designs and depths on the stress field developed in maxillary central incisors restored with veneers made with different ceramic materials using finite element analysis (FEA). MATERIALS AND METHODS A linear static three-dimensional finite element analysis model was used with the aid of reverse engineering to develop digital models of maxillary central incisors restored with ceramic veneers, according to two different preparation depths (thin vs deep) and two different preparation designs (feather edge vs butt joint). Three ceramic systems were tested: (i) feldspathic porcelain, (ii) heat pressed glass ceramic IPS Empress 2 (Ivoclar Vivadent AG), and (iii) heat pressed glass ceramic IPS e.max-Press (Ivoclar Vivadent AG). Each model was subjected to a compressive force of 200N applied to the palatal surface 2 mm below the incisal edge. The longitudinal axis of the restored tooth formed an angle of 130o with the direction of the force. The biomechanical behavior of the different models was examined according to the von Mises stress criterion. Statistical analysis was performed using nonparametric confidence interval estimation using bootstrapping. RESULTS The maximum observed stress values were calculated and found to be similar between prepared and intact teeth. The cervical margin of the veneers displayed the highest von Mises stress values. Irrespectively of the depth and preparation design, the biggest von Mises stress values were observed at the veneer structures with the following order: (i) IPS Empress 2, (ii) IPS e.max-Press, (iii) feldspathic (p = 0.001). Preparation depth resulted in statistically significant differences (p = 0.001) in the stress distribution in the majority of tested structures. As the preparation depth was increased, the stresses within the veneer structure and the tooth structures were decreased. No statistically significant differences were detected in the stresses among the different restored models, when the preparation design was considered. CONCLUSIONS This FEA study suggests that ceramic veneers could restore the biomechanical behavior of prepared central incisors and made it similar of that of an intact tooth. Regardless of the preparation depth and design and the ceramic system used, the cervical margin of ceramic veneers presents the highest von Mises stress values. When feldspathic porcelain was compared with lithium disilicate (IPS e.max Press), the latter displayed the lowest transfer of stresses to dental tissues. An increase in preparation depth resulted in a statistically significant stress decrease in both the veneer and the tooth.
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Affiliation(s)
- Alexandros Tsouknidas
- Department of Mechanical Engineering, University of Western Macedonia, Kozani, Greece
| | - Eleni Karaoglani
- Department of Prosthodontics, Aristotle University School of Dentistry, Thessaloniki, Greece
| | - Nikolaos Michailidis
- Mechanical Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Dimitris Kugiumtzis
- Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Argiris Pissiotis
- Department of Prosthodontics, Aristotle University School of Dentistry, Thessaloniki, Greece
| | - Konstantinos Michalakis
- Department of Prosthodontics, Aristotle University School of Dentistry, Thessaloniki, Greece.,Department of Prosthodontics, Tufts University, 1 Kneeland St., Boston, MA
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Chai SY, Bennani V, Aarts JM, Lyons K. Incisal preparation design for ceramic veneers: A critical review. J Am Dent Assoc 2019; 149:25-37. [PMID: 29304908 DOI: 10.1016/j.adaj.2017.08.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/23/2017] [Accepted: 08/26/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND The authors reviewed and identified the evidence for the various incisal preparation designs for ceramic veneers. TYPES OF STUDIES REVIEWED The authors searched MEDLINE with PubMed and Ovid to identify any articles in the English language related to the topic up through March 2017 using a combination of key words: "porcelain veneer or ceramic veneer or dental veneer or labial veneer" AND "preparation," NOT "composite veneer," NOT "crown," NOT "implant," NOT "fixed partial denture or bridge or denture," NOT "porcelain-fused-to-metal," NOT "marginal gap or fit." RESULTS In vitro studies showed that the palatal chamfer preparation design increases the risk of developing ceramic fractures. The butt joint preparation design had the least effect on the strength of the tooth. CONCLUSIONS Surveys show the 2 most common incisal preparation designs provided are butt joint and feathered-edge. Clinical studies have identified that incisal ceramic is the most common location of ceramic fracture. In addition, there is a lack in standardization of the modeling structures and type of finite element analysis. PRACTICAL IMPLICATIONS The evidence seems to support the use of butt joint over palatal chamfer incisal preparation design. Fracture or chipping is the most frequent complication and the risk increases with time. Incisal ceramic is the most common location of ceramic fracture.
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Zarone F, Di Mauro MI, Ausiello P, Ruggiero G, Sorrentino R. Current status on lithium disilicate and zirconia: a narrative review. BMC Oral Health 2019; 19:134. [PMID: 31272441 PMCID: PMC6610968 DOI: 10.1186/s12903-019-0838-x] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/27/2019] [Indexed: 01/28/2023] Open
Abstract
Background The introduction of the new generation of particle-filled and high strength ceramics, hybrid composites and technopolymers in the last decade has offered an extensive palette of dental materials broadening the clinical indications in fixed prosthodontics, in the light of minimally invasive dentistry dictates. Moreover, last years have seen a dramatic increase in the patients’ demand for non-metallic materials, sometimes induced by metal-phobia or alleged allergies. Therefore, the attention of scientific research has been progressively focusing on such materials, particularly on lithium disilicate and zirconia, in order to shed light on properties, indications and limitations of the new protagonists of the prosthetic scene. Methods This article is aimed at providing a narrative review regarding the state-of-the-art in the field of these popular ceramic materials, as to their physical-chemical, mechanical and optical properties, as well as to the proper dental applications, by means of scientific literature analysis and with reference to the authors’ clinical experience. Results A huge amount of data, sometimes conflicting, is available today. Both in vitro and in vivo studies pointed out the outstanding peculiarities of lithium disilicate and zirconia: unparalleled optical and esthetic properties, together with high biocompatibility, high mechanical resistance, reduced thickness and favorable wear behavior have been increasingly orientating the clinicians’ choice toward such ceramics. Conclusions The noticeable properties and versatility make lithium disilicate and zirconia materials of choice for modern prosthetic dentistry, requiring high esthetic and mechanical performances combined with a minimal invasive approach, so that the utilization of such metal-free ceramics has become more and more widespread over time.
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Affiliation(s)
- Fernando Zarone
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
| | - Maria Irene Di Mauro
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy.
| | - Pietro Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
| | - Gennaro Ruggiero
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
| | - Roberto Sorrentino
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
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Celebi AT, Icer E, Eren MM, Baykasoglu C, Mugan A, Yildiz E. Thermal-stress analysis of ceramic laminate veneer restorations with different incisal preparations using micro-computed tomography-based 3D finite element models. J Mech Behav Biomed Mater 2017; 75:302-313. [PMID: 28768230 DOI: 10.1016/j.jmbbm.2017.07.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 11/30/2022]
Abstract
Main objective of this study is to investigate the thermal behavior of ceramic laminate veneer restorations of the maxillary central incisor with different incisal preparations such as butt joint and palatinal chamfer using finite element method. In addition, it is also aimed to understand the effect of different thermal loads which simulates hot and cold liquid imbibing in the mouth. Three-dimensional solid models of the sound tooth and prepared veneer restorations were obtained using micro-computed tomography images. Each ceramic veneer restoration was made up of ceramic, luting resin cement and adhesive layer which were generated based on the scanned images using computer-aided design software. Our solid model also included the remaining dental tissues such as periodontal ligament and surrounding cortical and spongy bones. Time-dependent linear thermal analyses were carried out to compare temperature changes and stress distributions of the sound and restored tooth models. The liquid is firstly in contact with the crown area where the maximum stresses were obtained. For the restorations, stresses on palatinal surfaces were found larger than buccal surfaces. Through interior tissues, the effect of thermal load diminished and smaller stress distributions were obtained near pulp and root-dentin regions. We found that the palatinal chamfer restoration presents comparatively larger stresses than the butt joint preparation. In addition, cold thermal loading showed larger temperature changes and stress distributions than those of hot thermal loading independent from the restoration technique.
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Affiliation(s)
- Alper Tunga Celebi
- Southern Methodist University, Lyle School of Engineering, Department of Mechanical Engineering, 3101 Dyer Street, Dallas, TX 75205, USA.
| | - Esra Icer
- Technische Universität München, Department of Computer Science, 85748 Garching, Germany.
| | - Meltem Mert Eren
- Altınbaş University, Faculty of Dentistry, Department of Restorative Dentistry, Incirli Street No 11 Bakırköy, Istanbul, Turkey.
| | - Cengiz Baykasoglu
- Hitit University, Faculty of Engineering, Department of Mechanical Engineering, Cevre Yolu Avenue, 19030 Corum, Turkey.
| | - Ata Mugan
- Istanbul Technical University, Faculty of Mechanical Engineering, Inonu Street, Gumussuyu, 34437 Istanbul, Turkey.
| | - Esra Yildiz
- Istanbul University, Faculty of Dentistry, Department of Operative Dentistry, 34093 Capa, Istanbul, Turkey.
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Zhang Q, Goodman SB, Maloney WJ, Huddleston JI. Can a Conical Implant Successfully Address Complex Anatomy in Primary THA? Radiographs and Hip Scores at Early Followup. Clin Orthop Relat Res 2016; 474:459-64. [PMID: 26245165 PMCID: PMC4709298 DOI: 10.1007/s11999-015-4480-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Total hip arthroplasty (THA) in patients with small or abnormal proximal femoral anatomy is challenging as a result of complex anatomic deformities in the hip. It is unclear which stem is the most appropriate for these patients. One possible implant design that may help meet this need is the modified Wagner Cone prosthesis, whose design consists of monoblock cone with splines; however, to our knowledge, no clinical results have been published using this implant. QUESTIONS/PURPOSES We evaluated the hip scores and radiographic results (including signs of osseointegration and subsidence) of complex primary THA using the modified Wagner Cone cementless femoral component in patients with small or abnormal proximal femoral anatomic proportions. METHODS Between 2006 and 2011, we performed 59 THAs on patients whose femoral geometry precluded the use of standard-sized implants. Of these, 49 (83%) received the modified Wagner Cone prosthesis. During this time, our indications for use of the Wagner Cone implant in such patients included: femoral neck retroversion, excessive anteversion of the femoral neck, or small proximal femora not suitable for standard implants. Of those, 40 patients with 49 THAs were available for radiographic and clinical followup at a minimum of 3 years, and no patients were lost to followup. The diagnosis included developmental dysplasia of hip (22 patients, 28 hips), secondary trauma or posttuberculosis osteoarthritis (nine patients, 10 hips), and hip disease secondary to other disorders (eight patients, nine hips) and osteonecrosis (one patients, two hips). Two versions of the stem with 135° (28 hips) or 125° (21 hips) neck angle versions were used to reestablish normal hip biomechanics. Version angle was chosen based on preoperative templating. Cementless cups with screws were used for the acetabulum. Mean followup was 4 years (range, 3-7 years). Study endpoints were the Harris hip score and radiographic evaluations by a surgeon not involved in the clinical care of the patients (QZ); radiographic analysis included evaluating for the presence or absence of signs of osseointegration (including Engh's criteria) and subsidence. RESULTS The Harris hip score improved from a mean of 41 ± 9 preoperatively to a mean of 85 ± 10 at last followup (p < 0.01). The mean vertical subsidence was 1.5 ± 1.1 mm. Radiographic evaluation demonstrated stability (no further subsidence) of all implants at last followup. Endosteal spot welds were found in 32 hips (65%). No progressive radiolucencies were observed. One patient (one hip) underwent revision surgery as a result of late infection; no other revisions were performed. CONCLUSIONS The modified Wagner Cone femoral stem has provided improvements in hip scores and promising short-term radiographic results at short-term followup in complex cementless THA associated with abnormal or small femoral anatomical proportions in which standard implants are inappropriate. Longer followup will be needed to see if these results endure. Randomized trials are needed to determine the optimal stem design for these patients. LEVEL OF EVIDENCE Level IV, therapeutic study.
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Affiliation(s)
- Quoqiang Zhang
- Department of Orthopaedic Surgery, Stanford University Medical Center, 450 Broadway Street, MC 6342, Redwood City, CA 94063-6342 USA
| | - Stuart B. Goodman
- Department of Orthopaedic Surgery, Stanford University Medical Center, 450 Broadway Street, MC 6342, Redwood City, CA 94063-6342 USA
| | - William J. Maloney
- Department of Orthopaedic Surgery, Stanford University Medical Center, 450 Broadway Street, MC 6342, Redwood City, CA 94063-6342 USA
| | - James I. Huddleston
- Department of Orthopaedic Surgery, Stanford University Medical Center, 450 Broadway Street, MC 6342, Redwood City, CA 94063-6342 USA
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Influence of orthotropy on biomechanics of peri-implant bone in complete mandible model with full dentition. BIOMED RESEARCH INTERNATIONAL 2014; 2014:709398. [PMID: 25530968 PMCID: PMC4235237 DOI: 10.1155/2014/709398] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/01/2014] [Accepted: 09/01/2014] [Indexed: 11/19/2022]
Abstract
Objective. The study was to investigate the impact of orthotropic material on the biomechanics of dental implant, based on a detailed mandible with high geometric and mechanical similarity. Materials and Methods. Multiple data sources were used to elaborate detailed biological structures and implant CAD models. In addition, an extended orthotropic material assignment methodology based on harmonic fields was used to handle the alveolar ridge region to generate compatible orthotropic fields. The influence of orthotropic material was compared with the commonly used isotropic model and simplified orthotropic model. Results. The simulation results showed that the values of stress and strain on the implant-bone interface almost increased in the orthotropic model compared to the isotropic case, especially for the cancellous bone. However, the local stress concentration was more obvious in the isotropic case compared to that in orthotropic case. The simple orthotropic model revealed irregular stress and strain distribution, compared to the isotropic model and the real orthotropic model. The influence of orthotropy was little on the implant, periodontal ligament, tooth enamel, and dentin. Conclusion. The orthotropic material has significant effect on stress and strain of implant-bone interface in the mandible, compared with the isotropic simulation. Real orthotropic mechanical properties of mandible should be emphasized in biomechanical studies of dental implants.
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A three-dimensional finite element study on anterior laminate veneers with different incisal preparations. J Prosthet Dent 2014; 112:325-33. [DOI: 10.1016/j.prosdent.2013.09.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 09/02/2013] [Accepted: 09/04/2013] [Indexed: 11/20/2022]
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Alghazzawi TF, Lemons J, Liu PR, Essig ME, Janowski GM. The failure load of CAD/CAM generated zirconia and glass-ceramic laminate veneers with different preparation designs. J Prosthet Dent 2013; 108:386-93. [PMID: 23217471 DOI: 10.1016/s0022-3913(12)60198-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
STATEMENT OF PROBLEM Fracture of feldspathic porcelain laminate veneers represents a significant mode of clinical failure. Therefore, ceramic materials that withstand a higher load to fracture, especially for patients with parafunctional habits, are needed. PURPOSE The purpose of this study was to examine the correlation of material (zirconia, TZP, glass-ceramic, IEC, and feldspathic porcelain, FP) design (incisal overlapped preparation, IOP, and three-quarter preparation, TQP), and fracture mode to failure load for veneers supported by composite resin abutments. MATERIAL AND METHODS A typodont tooth prepared with 2 designs (IOP, TQP) and the corresponding 2 definitive dies were used to fabricate the composite resin abutments (30 for IOP and 30 for TQP). Ten veneer specimens for each system (Y-TZP, IEC, and FP), were fabricated for each design. The veneers were cemented, invested, and tested in compression until failure by using a universal testing machine. Significant differences were evaluated by 2-factor ANOVA (α=.05). RESULTS No statistical mean load difference was noted between the preparation designs for Y-TZP (IOP: 244 ±81 and TQP: 224 ±58 N), IEC (IOP: 306 ±101 and TQP: 263 ±77 N), and FP veneers (IOP: 161 ±93 and TQP: 246 ±45 N). No statistical difference in the mean load was found among the 3 veneer materials for each preparation design except between IEC (306 ±101 N) and FP (161 ±93 N) veneers for TQP. CONCLUSIONS Preparation design did not influence the failure load of the veneer materials. Zirconia veneers were the least likely to fracture but the most likely to completely debond; feldspathic porcelain veneers exhibited the opposite characteristics.
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Affiliation(s)
- Tariq F Alghazzawi
- College of Dentistry, Taibah University, Kingdom of Saudi Arabia, Taibah University, Kingdom of Saudi Arabia.
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González-Lluch C, Pérez-González A, Sancho-Bru JL, Rodríguez-Cervantes PJ. Mechanical performance of endodontic restorations with prefabricated posts: sensitivity analysis of parameters with a 3D finite element model. Comput Methods Biomech Biomed Engin 2012; 17:1108-18. [PMID: 23148761 DOI: 10.1080/10255842.2012.737459] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Many studies have investigated the effect of different parameters of the endodontically restored tooth on its final strength, using in vitro tests and model simulations. However, the differences in the experimental set-up or modelling conditions and the limited number of parameters studied in each case prevent us from obtaining clear conclusions about the relative importance of each parameter. In this study, a validated 3D biomechanical model of the restored tooth was used for an exhaustive sensitivity analysis. The individual influence of 20 different parameters on the mechanical performance of an endodontic restoration with prefabricated posts was studied. The results bring up the remarkable importance of the loading angle on the final restoration strength. Flexural loads are more critical than compressive or tensile loads. Young's modulus of the post and its length and diameter are the most influential parameters for strength, whereas other parameters such as ferrule geometry or core and crown characteristics are less significant.
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Affiliation(s)
- Carmen González-Lluch
- a Departament d'Enginyeria Mecànica i Construcció , Universitat Jaume I , Campus de Riu Sec. Avinguda Vicent Sos Baynat s/n. 12071, Castelló de la Plana , Spain
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14
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Liao SH, Zou BJ, Geng JP, Wang JX, Ding X. Physical modeling with orthotropic material based on harmonic fields. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2012; 108:536-547. [PMID: 21570147 DOI: 10.1016/j.cmpb.2011.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 04/07/2011] [Accepted: 04/24/2011] [Indexed: 05/30/2023]
Abstract
Although it is well known that human bone tissues have obvious orthotropic material properties, most works in the physical modeling field adopted oversimplified isotropic or approximated transversely isotropic elasticity due to the simplicity. This paper presents a convenient methodology based on harmonic fields, to construct volumetric finite element mesh integrated with complete orthotropic material. The basic idea is taking advantage of the fact that the longitudinal axis direction indicated by the shape configuration of most bone tissues is compatible with the trajectory of the maximum material stiffness. First, surface harmonic fields of the longitudinal axis direction for individual bone models were generated, whose scalar distribution pattern tends to conform very well to the object shape. The scalar iso-contours were extracted and sampled adaptively to construct volumetric meshes of high quality. Following, the surface harmonic fields were expanded over the whole volumetric domain to create longitudinal and radial volumetric harmonic fields, from which the gradient vector fields were calculated and employed as the orthotropic principal axes vector fields. Contrastive finite element analyses demonstrated that elastic orthotropy has significant effect on simulating stresses and strains, including the value as well as distribution pattern, which underlines the relevance of our orthotropic modeling scheme.
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Affiliation(s)
- Sheng-Hui Liao
- School of Information Science and Engineering, Central South University, Changsha 410083, China.
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15
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Girard J, Roche O, Wavreille G, Canovas F, Le Béguec P. Stem subsidence after total hip revision: 183 cases at 5.9 years follow-up. Orthop Traumatol Surg Res 2011; 97:121-6. [PMID: 21435964 DOI: 10.1016/j.otsr.2010.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 09/16/2010] [Accepted: 10/15/2010] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Secondary subsidence of a revision femoral stem is often a negative predictive sign for successful osseointegration and perfect long-term stability. MATERIALS AND METHODS We performed a retrospective study in a series of 183 revision total hip replacements between 1996 and 2000 to evaluate the importance and risk factors of secondary subsidence with a cementless press-fit design femoral stem as well as this subsidence's consequences to osseointegration. RESULTS Secondary subsidence did not occur in 80 cases (53%), was between 0 and 4mm in 41 cases (27%); between 5 and 10mm in 17 cases (12%) and was greater than 10mm in 12 cases (8%). Mean subsidence of all patients was 3mm (0-30). There was a statistically significant negative correlation between subsidence and the quality of osseointegration (P=0.03). There was no significant relationship between component diameter and stem subsidence (P=0.9). The presence of preoperative bone deficiencies did not increase the risk of secondary subsidence (P=0.2). CONCLUSION In the case of revision with press-fit stems, the importance of secondary subsidence should not be overestimated, because it usually does not negatively affect satisfactory osseointegration.
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Affiliation(s)
- J Girard
- Sports and Medicine Unit, North Lille University, 59000 Lille, France.
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Zarone F, Russo S, Sorrentino R. From porcelain-fused-to-metal to zirconia: Clinical and experimental considerations. Dent Mater 2011; 27:83-96. [DOI: 10.1016/j.dental.2010.10.024] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 10/22/2010] [Indexed: 10/18/2022]
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