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Weimann D, Fleck C, Razi H. Marginal integrity in minimally invasive molar resin composite restorations: Impact of polymerization shrinkage. J Mech Behav Biomed Mater 2024; 155:106554. [PMID: 38676971 DOI: 10.1016/j.jmbbm.2024.106554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/29/2024]
Abstract
OBJECTIVES This study utilized non-linear finite element (FE) models to explore polymerization shrinkage and its impact on marginal integrity in molars following both selective caries removal (SCR) and conventional treatment. Specifically, we performed 2D in silico simulations to study residual stresses post-resin polymerization shrinkage and their influence on the marginal integrity of various restoration types. METHODS Initially, FE models were developed based on a cohesive zone framework to simulate crack propagation along the bonded interfaces between restoration and tooth structure in SCR-treated molars with class I and class II restorations. The modeled resin composite restorations first underwent polymerization shrinkage and were then subjected to various occlusal loading conditions. Stress magnitudes and distributions were identified to evaluate the margin integrity and predict the mechanism and location of interfacial failure. RESULTS AND DISCUSSION The FE models computed polymerization shrinkage stresses of less than 1 MPa, exerting a minor influence on the composite/tooth interface. Occlusal loading, however, significantly impacted the load-bearing capacity of the composite/tooth (c/t) interface, potentially jeopardizing the restoration integrity. Especially under bi-axial occlusal loading, interfacial debonding occurred in the vertical cavity walls of the class I restorations, increasing the risk of failure. Notably, SCR-treated teeth exhibited better margin integrity than restored teeth after complete caries removal (NCR). These findings provide valuable insights into the mechanical behavior of SCR-treated teeth under different loading conditions and highlight the importance of considering the load scenarios that may lead to failure at the c/t interface. By investigating the factors influencing crack initiation and delamination, this novel research contributes to the optimization of restorative treatments and aids in the design of more resilient dental restorations.
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Affiliation(s)
- Dominique Weimann
- Materials Science and Engineering, Technische Universität Berlin, Berlin, Germany
| | - Claudia Fleck
- Materials Science and Engineering, Technische Universität Berlin, Berlin, Germany.
| | - Hajar Razi
- ETH Zurich, Zurich, Switzerland; WoodTec Group, Cellulose & Wood Materials Laboratory, Empa, Dübendorf, Switzerland.
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Sukkasam C, Kamonkhantikul K, Homsiang W, Arksornnukit M. In vitro damping and strain distribution for implant-supported crowns using 5 different CAD-CAM crowns and 3 different luting cements. J Prosthet Dent 2024; 131:916.e1-916.e9. [PMID: 38443240 DOI: 10.1016/j.prosdent.2024.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 03/07/2024]
Abstract
STATEMENT OF PROBLEM Dental implants are particularly susceptible to occlusal overloading because, unlike natural teeth, they lack a periodontal ligament to help absorb occlusal forces. However, studies evaluating the impact of different crown and luting materials on the damping behavior and strain distribution of implant-supported crowns are lacking. PURPOSE The purpose of this in vitro study was to investigate the damping behavior and strain distribution of peri-implant bone associated with 5 different CAD-CAM implant-supported crowns and 3 luting materials. MATERIAL AND METHODS A titanium implant was embedded in a plastic tube with epoxy resin and 5 different crown materials (polymethyl methacrylate, resin-infiltrated ceramic, lithium disilicate, titanium, and zirconia) luted to prosthetic abutments with 3 different luting materials (zinc oxide non-eugenol cement, zinc phosphate cement, and adhesive resin cement) and an uncemented condition were tested (n=5). Strain gauges were attached at the crestal and apical levels of the implant model. All specimens were load tested from 0 to 200 N. Slopes of load/time, microstrain/time, and time required to reach the maximum load were examined to represent the damping behavior. Absolute maximum strain (AMS) and its occurrence level were examined to represent the strain distribution. Two-way ANOVA, followed by the Tukey HSD test, were used for statistical analysis (α=.05). RESULTS All slopes and times to reach the maximum load in each crown material were statistically similar (P>.05), except for the polymethyl methacrylate group, which showed less steepness in all slopes and more time required to reach the maximum load significantly (P<.05). Both the polymethyl methacrylate group (224.5 ±30.2) and the titanium group (224.0 ±24.3) exhibited significantly higher AMS at the crestal level compared with the resin-infiltrated ceramic group (210.6 ±5.0) (P<.05). The lithium disilicate (218.1 ±15.0) and zirconia groups (217.3 ±14.8) demonstrated comparable AMS values with the others (P>.05). The uncemented group demonstrated steeper slopes and less time required to reach the maximum load compared with the adhesive resin group (P<.05), while slopes and times of the zinc phosphate and zinc oxide non-eugenol groups were comparable (P>.05). The uncemented group (242.7 ±25.3) exhibited significantly higher AMS at the crestal level than the other groups (P<.05). CONCLUSIONS The crown material significantly affected the damping behavior of peri-implant bone, unlike the luting material. Polymethyl methacrylate with a high damping behavior exhibited high strain at the crestal level. In contrast, resin-modified ceramic with a moderate damping behavior exhibited low strain at the crestal level. Strain at the crestal level could be effectively reduced by approximately 13% through cementation.
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Affiliation(s)
- Charnikan Sukkasam
- Postgraduate student, Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Krid Kamonkhantikul
- Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
| | - Woraporn Homsiang
- Lecturer, Department of Family and Community Dentistry, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand
| | - Mansuang Arksornnukit
- Professor, Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
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Sun Y, Liao L. Effects of surface nanomorphology on the senescence of periodontal ligament stem cells. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2024; 42:172-180. [PMID: 38597077 PMCID: PMC11034406 DOI: 10.7518/hxkq.2024.2023244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/16/2023] [Indexed: 04/11/2024]
Abstract
OBJECTIVES The effect of TiO2 nanotube morphology on the differentiation potency of senescent periodontal ligament stem cells was investigated. METHODS Two types of titanium sheets with TiO2 nanotube morphology (20V-NT and 70V-NT) were prepared via anodic oxidation at 20 and 70 V separately, and their surface morphology was observed. Young periodontal ligament stem cells were cultivated in an osteogenic induction medium, and the most effective surface morphology in promoting osteogenic differentiation was selected. RO3306 and Nutlin-3a were used to induce the aging of young periodontal ligament stem cells, and senescent periodontal ligament stem cells were obtained. The osteogenic differentiation of senescent periodontal ligament stem cells was induced, and the effect of surface morphology on osteogenic differentiation was observed. RESULTS Nanotube morphology was achieved on the surfaces of titanium sheets through anodic oxidation, and the diameters of the nanotubes increased with voltage. A significant difference in the effect of nanotube morphology was found among nanotubes with different diameters in the young periodontal ligament stem cells. The surface nanotube morphology of 20V-NT had a more significant effect that promoted osteogenic differentiation. Compared with a smooth titanium sheet, the surface nanotube morphology of 20V-NT increased the number of alkaline phosphatase-positive senescent periodontal ligament stem cells and promoted calcium deposition and the expression of osteogenic marker genes Runt-related transcription factor 2, osteopontin, and osteocalcin. CONCLUSIONS A special nanotube morphology enhances the differentiation ability of senescent periodontal ligament stem cells, provides an effective method for periodontal regeneration, and further improves the performance of implants.
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Affiliation(s)
- Yanping Sun
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Engineering Research Center of Oral Translational Medicine, Ministry of Education & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Li Liao
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Engineering Research Center of Oral Translational Medicine, Ministry of Education & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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Velasco-Ortega E, Jiménez-Guerra A, Ortiz-Garcia I, Nuñez-Márquez E, Moreno-Muñoz J, Gil J, Delgado LM, Rondón-Romero JL, Monsalve-Guil L. Silver coating on dental implant-abutment connection screws as potential strategy to prevent loosening and minimizing bacteria adhesion. Front Bioeng Biotechnol 2024; 11:1293582. [PMID: 38264580 PMCID: PMC10803504 DOI: 10.3389/fbioe.2023.1293582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/21/2023] [Indexed: 01/25/2024] Open
Abstract
Introduction: One of the main problems for the long-term behavior of dental implants are loosening of the implant-abutment connection screws and bacterial infiltration. The aim of this work is to increase the screw fixation by silver coating, providing superior mechanical retaining and antibacterial effect. Methods: Eighty dental implants with their abutments and screws have been studied. Twenty screws were not coated and were used as a control while the rest of screws were silver coated by sputtering, with three different thickness: 10, 20 and 40 μm and 20 screws per each thickness. Coating morphology and thickness were determined by scanning electron microscopy using image analysis systems. The screws were tightened for each of the thicknesses and the control with two torques 15 Ncm and 20 Ncm and tested under mechanical fatigue simulating oral stresses up to a maximum of 500,000 cycles. The remaining torques at different cycles were determined with a high-sensitivity torquemeter. Cell viability assays were performed with SaOs-2 osteoblasts and microbiological studies were performed against Streptococcus gordonii and Enterococcus faecalis bacteria strains, determining their metabolic activity and viability using live/dead staining. Results: It was observed a decrease in torque as cycles increase. For a preload of 15 Ncm at 100,000 cycles, the loosening was complete and, for 20 Ncm at 500,000 cycles, 85% of torque was lost. The silver coatings retained the torque, especially the one with a thickness of 40 μm, retaining 90% of the initial torque at 500,000 cycles. It was observed that osteoblastic viability values did not reach 70%, which could indicate a slight cytotoxic effect in contact with cells or tissues; however, the screw should not be in direct contact with tissue or living cells. Silver coating induced a significant reduction of the bacteria metabolic activity for Streptococcus gordonii and Enterococcus faecalis, around 90% and 85% respectively. Discussion: Therefore, this coating may be of interest to prevent loosening of implant systems with a worthy antibacterial response.
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Affiliation(s)
- Eugenio Velasco-Ortega
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Alvaro Jiménez-Guerra
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Iván Ortiz-Garcia
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Enrique Nuñez-Márquez
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Jesús Moreno-Muñoz
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Javier Gil
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Luis M. Delgado
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Barcelona, Spain
| | - José Luis Rondón-Romero
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Loreto Monsalve-Guil
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
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Gomes C, Mesnard M, Ramos A. Bone density and proximal support effects on dental implant stability - Finite element analysis and in vitro experiments. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2023; 124:101512. [PMID: 37209971 DOI: 10.1016/j.jormas.2023.101512] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 03/19/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023]
Abstract
OBJECTIVES The application of dental implants presents the occurrence of implant failures associated with bone proximal support. This study aims to assess implant behavior, in particular implant stability and strain distribution in the bone at different bone densities, and the effect of proximal bone support. MATERIAL AND METHODS Three bone densities (D20, D15, and D10) were considered in the experimental in vitro study, represented by solid rigid polyurethane foam and two conditions of bone support in the proximal region. A finite element model was developed and validated experimentally and a Branemark model at a 3:1 scale was implanted in the experiments; the model was loaded and extracted. RESULTS The results of the experimental models validate the finite element models with a correlation R2 equal to 0.899 and NMSE of 7%. The implant extraction tests for the effect of bone properties in the maximum load were 2832 N for D20 and 792 N for D10. The effect of proximal bone support changes the implant stability was observed experimentally; at 1 mm less bone support decreases by 20% of stability and at 2 mm by 58% for D15 density. CONCLUSIONS Bone properties and bone quantity are important for the initial stability of the implant. A bone volume fraction of less than 24 g/cm3 exhibits poor behavior and is not indicated for implantation. Proximal bone support reduces the primary stability of the implant and the effect is critical in lower bone density.
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Affiliation(s)
- C Gomes
- University of Aveiro, Biomechanics Research Group, Department of Mechanical Engineering, Aveiro 3810-193, Portugal
| | - M Mesnard
- University de Bordeaux, Institut de Mécanique et d'Ingénierie, Department Ingénierie Mécanique et Conception, CNRS UMR 5295, Talence 33405, France
| | - A Ramos
- University of Aveiro, Biomechanics Research Group, Department of Mechanical Engineering, Aveiro 3810-193, Portugal.
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Baghani Z, Soheilifard R, Bayat S. How Does the First Molar Root Location Affect the Critical Stress Pattern in the Periodontium? A Finite Element Analysis. JOURNAL OF DENTISTRY (SHIRAZ, IRAN) 2023; 24:182-193. [PMID: 37388195 PMCID: PMC10300141 DOI: 10.30476/dentjods.2022.93271.1704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 01/02/2022] [Accepted: 03/12/2022] [Indexed: 07/01/2023]
Abstract
Statement of the Problem The first molar root location plays a pivotal role in neutralization of forces applied to the teeth to prevent injury. Purpose This study aimed to assess the effect of maxillary and mandibular first molar root location on biomechanical behavior of the periodontium under vertical and oblique loadings. Materials and Method In this three-dimensional (3D) finite element analysis (FEA), the maxillary and mandibular first molars and their periodontium were modeled. The Young's modulus and the Poisson's ratio for the enamel, dentin, dental pulp, periodontal ligament (PDL), and cortical and cancellous bones were adopted from previous studies. The changes in maximum von Misses stress (MVMS) values of each component were analyzed. Results The MVMS values were the highest in the enamel followed by dentin, cortical bone, cancellous bone, and PDL. The maxillary and mandibular first molars with different root locations and their periodontium showed different biomechanical behaviors under the applied loads. Conclusion An interesting finding was that the stress concentration point in the path of load degeneration changed from the cervical third in dentin to the apical third in the cancellous bone, which can greatly help in detection of susceptible areas over time.
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Affiliation(s)
- Zahra Baghani
- Dept. of Periodontics, Faculty of Dentistry, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Reza Soheilifard
- Dept. of Mechanical Engineering Hakim Sabzevari University Sabzevar, Iran
| | - Sahar Bayat
- Student, Dept. of Civil Engineering, Hakim Sabzevari University, Sabzevar, Iran
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Attia MA, Blunt L, Bills P, Tawfik A, Radawn M. Micro-CT analysis of marginal and internal fit of milled and pressed polyetheretherketone single crowns. J Prosthet Dent 2023:S0022-3913(23)00183-X. [PMID: 37072286 DOI: 10.1016/j.prosdent.2023.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 04/20/2023]
Abstract
STATEMENT OF PROBLEM Polyetheretherketone (PEEK) has been increasingly used as a framework material in prosthetic dentistry. However, data on the marginal and internal fit of PEEK restorations fabricated by using either the computer-aided design and computer-aided manufacturing (CAD-CAM) or heat-pressing technique are sparse. PURPOSE The aim of this in vitro study was to assess the marginal and internal fit of milled and pressed PEEK single crowns by using microcomputed tomography (μCT). MATERIAL AND METHODS A custom-made, single stainless-steel die was designed to replicate a maxillary first premolar prepared for a ceramic crown. PEEK copings (N=30) were fabricated and allocated to 3 groups (n=10) according to the fabrication technique: milled from a prefabricated PEEK blank, heat pressed from PEEK pellets, and heat pressed from PEEK granules. All copings were veneered with a composite resin material. The marginal fit was recorded at 4 predetermined points and the internal fit at 8 predetermined points on each crown by using μCT. Two-way ANOVA, pair-wise Tukey honestly significant difference (HSD), and simple main effect tests were used for statistical analysis of the data (α=.05). RESULTS Concerning marginal fit, the milled crowns demonstrated the best marginal fit overall (44 ±3 μm), followed by those pressed from pellets (92 ±3 μm), and finally by those pressed from granules (137 ±7 μm) (P<.001). The interaction between the effects of the fabrication technique and the measurement point on the marginal fit was not statistically significant (P=.142). The milled crowns demonstrated the lowest mean gap values overall, followed by those pressed from pellets and those pressed from granules (P<.001). The interaction between the effects of the fabrication technique and the measurement point on the internal fit was statistically significant (P<.001). Except for the distal occlusal gap and mesial occlusal gap, all tested groups showed a statistically significant difference (P<.001). In addition, statistically significant differences were observed among all measurement points in different fabrication techniques (P<.001). CONCLUSIONS The marginal and internal fit of milled PEEK crowns was significantly better than pressed crowns. However, both CAD-CAM and heat-pressing techniques produced PEEK crowns with a clinically acceptable marginal and internal fit. The mean marginal gap of the PEEK crowns pressed from granules was above the range of clinically acceptable value.
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Affiliation(s)
- Mazen A Attia
- Associate Professor, Department of Fixed Prosthodontics, Faculty of Dentistry, Beni-Suef University, Beni-Suef, Egypt.
| | - Liam Blunt
- Professor, EPSRC Future Advanced Metrology Hub, University of Huddersfield, Huddersfield, United Kingdom
| | - Paul Bills
- Professor, EPSRC Future Advanced Metrology Hub, University of Huddersfield, Huddersfield, United Kingdom
| | - Ahmed Tawfik
- PhD Researcher, EPSRC Future Advanced Metrology Hub, University of Huddersfield, Huddersfield, United Kingdom
| | - Mohamed Radawn
- Lecturer, Department of Fixed Prosthodontics, Faculty of Dentistry, Beni-Suef University, Beni-Suef, Egypt
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Cuevas PL, Aellos F, Dawid IM, Helms JA. Wnt/β-Catenin Signaling in Craniomaxillofacial Osteocytes. Curr Osteoporos Rep 2023; 21:228-240. [PMID: 36807035 DOI: 10.1007/s11914-023-00775-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/29/2022] [Indexed: 02/23/2023]
Abstract
PURPOSE OF REVIEW There is a growing appreciation within the scientific community that cells exhibit regional variation. Whether the variation is attributable to differences in embryonic origin or anatomical location and mechanical loading has not been elucidated; what is clear, however, is that adult cells carry positional information that ultimately affects their functions. The purpose of this review is to highlight the functions of osteocytes in the craniomaxillofacial (CMF) skeleton as opposed to elsewhere in the body, and in doing so gain mechanistic insights into genetic conditions and chemically-induced diseases that particularly affect this region of our anatomy. RECENT FINDINGS In the CMF skeleton, elevated Wnt/β-catenin signaling affects not only bone mass and volume, but also mineralization of the canalicular network and osteocyte lacunae. Aberrant elevation in the Wnt/β-catenin pathway can also produce micropetrosis and osteonecrosis of CMF bone, presumably due to a disruption in the signaling network that connects osteocytes to one another, and to osteoblasts on the bone surface.
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Affiliation(s)
- Pedro L Cuevas
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 1651 Page Mill Road, Palo Alto, CA, 94305, USA
| | - Fabiana Aellos
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 1651 Page Mill Road, Palo Alto, CA, 94305, USA
| | - Isaiah M Dawid
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 1651 Page Mill Road, Palo Alto, CA, 94305, USA
| | - Jill A Helms
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 1651 Page Mill Road, Palo Alto, CA, 94305, USA.
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Fischer NG, Aparicio C. Junctional epithelium and hemidesmosomes: Tape and rivets for solving the "percutaneous device dilemma" in dental and other permanent implants. Bioact Mater 2022; 18:178-198. [PMID: 35387164 PMCID: PMC8961425 DOI: 10.1016/j.bioactmat.2022.03.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/14/2022] [Accepted: 03/12/2022] [Indexed: 02/06/2023] Open
Abstract
The percutaneous device dilemma describes etiological factors, centered around the disrupted epithelial tissue surrounding non-remodelable devices, that contribute to rampant percutaneous device infection. Natural percutaneous organs, in particular their extracellular matrix mediating the "device"/epithelium interface, serve as exquisite examples to inspire longer lasting long-term percutaneous device design. For example, the tooth's imperviousness to infection is mediated by the epithelium directly surrounding it, the junctional epithelium (JE). The hallmark feature of JE is formation of hemidesmosomes, cell/matrix adhesive structures that attach surrounding oral gingiva to the tooth's enamel through a basement membrane. Here, the authors survey the multifaceted functions of the JE, emphasizing the role of the matrix, with a particular focus on hemidesmosomes and their five main components. The authors highlight the known (and unknown) effects dental implant - as a model percutaneous device - placement has on JE regeneration and synthesize this information for application to other percutaneous devices. The authors conclude with a summary of bioengineering strategies aimed at solving the percutaneous device dilemma and invigorating greater collaboration between clinicians, bioengineers, and matrix biologists.
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Affiliation(s)
- Nicholas G. Fischer
- MDRCBB-Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN, 55455, USA
| | - Conrado Aparicio
- MDRCBB-Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN, 55455, USA
- Division of Basic Research, Faculty of Odontology, UIC Barcelona – Universitat Internacional de Catalunya, C/. Josep Trueta s/n, 08195, Sant Cugat del Valles, Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), C/. Baldiri Reixac 10-12, 08028, Barcelona, Spain
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López-Píriz R, Goyos-Ball L, Cabal B, Martínez S, Moya JS, Bartolomé JF, Torrecillas R. New Ceramic Multi-Unit Dental Abutments with an Antimicrobial Glassy Coating. MATERIALS (BASEL, SWITZERLAND) 2022; 15:5422. [PMID: 35955356 PMCID: PMC9369483 DOI: 10.3390/ma15155422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/24/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
The choice of suitable materials and new designs in oral implantology and the subsequent enhancement of the characteristics of the dental implant developed is an important research topic with wide scope. The present work aims to develop a new multifunctional zirconia-ceria/alumina (Ce-TZP/Al2O3) composite with an antimicrobial glass-based coating to be used in multi-unit abutments compatible with commercially available Ti implants for peri-implantitis prevention. An airbrush spraying technique was effectively applied to coat the sintered ceramic composite starting from a glass powder suspension. This deposition technique was appropriate for obtaining continuous antimicrobial glass-based coatings with homogenous thickness (~35 µm) on ceramic dental implant components. The dental implant systems with the antimicrobial glassy coating were subjected to a mechanical integrity test following ISO 14801 to determine their long-term stability. The tested implant-coating structure seems to be stable under in vitro conditions with ultimate applied forces exceeding the maximum physiological occlusal loading force. This paper also presents a pilot clinical case report that shows peri-implant tissue around the mechanically stable glass coating with no signs of inflammation 1 year after implant insertion. This result is a preliminary probe of the durability and biological tolerance of the glassy material by the gingiva, as well as the antimicrobial effect on the peri-implant microbiota displayed by the coating.
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Affiliation(s)
- Roberto López-Píriz
- Instituto de Cirugía Oral Avanzada-ICOA, Calle de Fray Luis de León, 14, 28012 Madrid, Spain
| | - Lidia Goyos-Ball
- Nanoker Research, Pol. Ind. Olloniego, Parcela 22A, Nave 5, 33660 Oviedo, Spain
| | - Belén Cabal
- Nanomaterials and Nanotechnology Research Centre (CINN), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Oviedo (UO), Principado de Asturias (PA), Avenida de la Vega 4-6, 33940 El Entrego, Spain
| | - Susana Martínez
- Nanoker Research, Pol. Ind. Olloniego, Parcela 22A, Nave 5, 33660 Oviedo, Spain
- Nanomaterials and Nanotechnology Research Centre (CINN), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Oviedo (UO), Principado de Asturias (PA), Avenida de la Vega 4-6, 33940 El Entrego, Spain
| | - José S. Moya
- Nanomaterials and Nanotechnology Research Centre (CINN), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Oviedo (UO), Principado de Asturias (PA), Avenida de la Vega 4-6, 33940 El Entrego, Spain
| | - José F. Bartolomé
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain
| | - Ramón Torrecillas
- Nanoker Research, Pol. Ind. Olloniego, Parcela 22A, Nave 5, 33660 Oviedo, Spain
- Nanomaterials and Nanotechnology Research Centre (CINN), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Oviedo (UO), Principado de Asturias (PA), Avenida de la Vega 4-6, 33940 El Entrego, Spain
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Polymer–Metal Composite Healthcare Materials: From Nano to Device Scale. JOURNAL OF COMPOSITES SCIENCE 2022. [DOI: 10.3390/jcs6080218] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Metals have been investigated as biomaterials for a wide range of medical applications. At nanoscale, some metals, such as gold nanoparticles, exhibit plasmonics, which have motivated researchers’ focus on biosensor development. At the device level, some metals, such as titanium, exhibit good physical properties, which could allow them to act as biomedical implants for physical support. Despite these attractive features, the non-specific delivery of metallic nanoparticles and poor tissue–device compatibility have greatly limited their performance. This review aims to illustrate the interplay between polymers and metals, and to highlight the pivotal role of polymer–metal composite/nanocomposite healthcare materials in different biomedical applications. Here, we revisit the recent plasmonic engineered platforms for biomolecules detection in cell-free samples and highlight updated nanocomposite design for (1) intracellular RNA detection, (2) photothermal therapy, and (3) nanomedicine for neurodegenerative diseases, as selected significant live cell–interactive biomedical applications. At the device scale, the rational design of polymer–metallic medical devices is of importance for dental and cardiovascular implantation to overcome the poor physical load transfer between tissues and devices, as well as implant compatibility under a dynamic fluidic environment, respectively. Finally, we conclude the treatment of these innovative polymer–metal biomedical composite designs and provide a future perspective on the aforementioned research areas.
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Tian Y, Sadowsky SJ, Brunski JB, Yuan X, Helms JA. Effects of masticatory loading on bone remodeling around teeth vs. implants: insights from a preclinical model. Clin Oral Implants Res 2022; 33:342-352. [PMID: 35051302 DOI: 10.1111/clr.13894] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 12/10/2021] [Accepted: 12/19/2021] [Indexed: 02/05/2023]
Abstract
OBJECTIVES Teeth connect to bone via a periodontal ligament whereas implants connect to bone directly. Consequently, masticatory loads are distributed differently to periodontal versus peri-implant bone. Our objective was to determine how masticatory loading of an implant versus a tooth affected peri-implant versus periodontal bone remodeling. Our hypothesis was that strains produced by functional loading of an implant would be elevated compared to the strains around teeth, and that this would stimulate a greater degree of bone turnover around implants versus in periodontal bone. MATERIALS AND METHODS Sixty skeletally mature mice were divided into two groups. In the Implant group, maxillary first molars (mxM1) were extracted, and after socket healing, titanium alloy implants were positioned sub-occlusally. After osseointegration, implants were exposed, resin crowns were placed, and masticatory loading was initiated. In a Control group the dentition was left intact. Responses of peri-implant and periodontal bone were measured using micro-CT, histology, bone remodeling assays, and quantitative histomorphometry while bone strains were estimated using finite element (FE) analyses. CONCLUSIONS When a submerged osseointegrated implant is exposed to masticatory forces peri-implant strains are elevated, and peri-implant bone undergoes significant remodeling that culminates in new bone accrual. The accumulation of new bone functions to reduce both peri-implant strains and bone remodeling activities, equivalent to those observed around the intact dentition.
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Affiliation(s)
- Ye Tian
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Division of Plastic and Reconstructive Surgery, Department of Surgery, School of Medicine, Stanford University, Palo Alto, California, 94305, USA
| | - Steven J Sadowsky
- University of the Pacific, Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA
| | - John B Brunski
- Division of Plastic and Reconstructive Surgery, Department of Surgery, School of Medicine, Stanford University, Palo Alto, California, 94305, USA
| | - Xue Yuan
- Division of Plastic and Reconstructive Surgery, Department of Surgery, School of Medicine, Stanford University, Palo Alto, California, 94305, USA
| | - Jill A Helms
- Division of Plastic and Reconstructive Surgery, Department of Surgery, School of Medicine, Stanford University, Palo Alto, California, 94305, USA
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13
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Yoo SY, Kim SK, Heo SJ, Koak JY. Clinical and radiographic evaluations of implants as surveyed crowns for Class I removable partial dentures: A retrospective study. J Adv Prosthodont 2022; 14:108-121. [PMID: 35601350 PMCID: PMC9095449 DOI: 10.4047/jap.2022.14.2.108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The purpose of this study was to evaluate survival rates and marginal bone loss (MBL) of implants in IC-RPDs. MATERIALS AND METHODS Seventy implants were placed and used as surveyed crowns in 30 RPDs. The survival rates and MBL around implants based on multiple variables, e.g., position, sex, age, opposing dentitions, splinting, type of used retainer, and first year bone loss, were analyzed. Patient reported outcome measures (PROMs) regarding functional/esthetic improvement after IC-RPD treatment, and complications were also inspected. RESULTS The 100% implant survival rates were observed, and 60 of those implants showed MBL levels less than 1.5 mm. No significant differences in MBL of implants were observed between implant positions (maxilla vs. mandible; P = .341) and type of used retainers (P = .630). The implant MBL of greater than 0.5 mm at 1 year showed significantly higher MBL after that (P < .001). Splinted implant surveyed crowns showed lower MBL in the maxilla (splinted vs. non-splinted; P = .037). There were significant esthetic/functional improvements observed after treatment, but there were no significant differences in esthetic results based on implant position (maxilla vs. mandible). Implants in mandible showed significantly greater improvement in function than implants in the maxilla (P = .002). Prosthetic complication of IC-RPD was not observed frequently. However, 2 abutment teeth among 60 were failed. The bone loss of abutment teeth was lower than MBL of implants in IC-RPDs (P = .001). CONCLUSION Class I RPD connected to residual teeth and strategically positioned implants as surveyed crowns can be a viable treatment modality.
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Affiliation(s)
- Soo-Yeon Yoo
- Department of Prosthodontics & Dental Research Institute, Seoul National University Dental Hospital, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Seong-Kyun Kim
- Department of Prosthodontics & Dental Research Institute, Seoul National University Dental Hospital, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Seong-Joo Heo
- Department of Prosthodontics & Dental Research Institute, Seoul National University Dental Hospital, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Jai-Young Koak
- Department of Prosthodontics & Dental Research Institute, Seoul National University Dental Hospital, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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14
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deMoya AV, Schmidt ER, Eckert GJ, Katona TR. The effects of a PDL analogue on occlusal contact forces. J Oral Rehabil 2021; 49:316-326. [PMID: 34731498 DOI: 10.1111/joor.13278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 08/28/2021] [Accepted: 09/27/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Previous bench-top studies examined the details of the mechanical environment of rigidly-fixed occluding teeth. It was demonstrated that during each chomp, contacting molar teeth experience in-occlusal-plane forces (Flateral ) that are highly transient in magnitude and direction. OBJECTIVES The objectives of this study are to identify Flateral behaviors that are attributable to the presence of a visco-elastic periodontal ligament (PDL) analogue, and to asses the necessity of incorporating it into future studies. METHODS A weighted maxillary molar denture tooth was lowered onto, and raised from, a matching mandibular molar 10 times. The latter was supported by a load cell that continuously measured Flateral . For statistical purposes, the test was repeated with 21 (n = 21) different occlusal relationships obtained with 0.05 mm incremental shifts of the lower assembly. RESULTS Overall, the results are similar to those of rigid attachment but the details of the Flateral profiles are very different. CONCLUSION The PDL plays a major role in the mechanical environment of occlusion, suggesting that, in general (not necessarily always), it should be integrated into studies of occlusion.
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Affiliation(s)
| | | | - George J Eckert
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, USA
| | - Thomas R Katona
- Department of Orthodontics and Oral Facial Genetics, Indiana University School of Dentistry, 1121 W. Michigan St, Indianapolis, IN, 46202, USA
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15
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Mechanical Performance of Chairside Ceramic CAD/CAM Restorations and Zirconia Abutments with Different Internal Implant Connections: In Vitro Study and Finite Element Analysis. MATERIALS 2021; 14:ma14175009. [PMID: 34501107 PMCID: PMC8434075 DOI: 10.3390/ma14175009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/14/2021] [Accepted: 08/27/2021] [Indexed: 11/17/2022]
Abstract
(computer-aided design-computer-aided manufacturing) CAD/CAM monolithic restorations connected to zirconia abutments manufactured with a chairside workflow are becoming a more common restorative option. However, their mechanical performance is still uncertain. The aim of this study was to evaluate the mechanical behavior of a combination of a zirconia abutment and monolithic all-ceramic zirconia and lithium disilicate crown manufactured with a chairside workflow, connected to titanium implants with two types of internal connection—tube in tube connection and conical connection with platform switching. They were thermally cycled from 5 °C to 55 °C and were subjected to a static and fatigue test following ISO 14801. The fractured specimens from the fatigue test were examined by SEM (scanning electron microscopy). Simulations of the stress distribution over the different parts of the restorative complex during the mechanical tests were evaluated by means of (finite element analysis) FEA. The mechanical performance of the zirconia abutment with an internal conical connection was higher than that of the tube in tube connection. Additionally, the use of disilicate or zirconia all-ceramic chairside CAD/CAM monolithic restorations has similar results in terms of mechanical fracture and fatigue resistance. Stress distribution affects the implant/restoration complex depending on the connection design. Zirconia abutments and monolithic restorations seem to be highly reliable in terms of mechanical resistance.
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16
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Şensoy AT, Çolak M, Kaymaz I, Findik F. An application of finite element method in material selection for dental implant crowns. ACTA ACUST UNITED AC 2021; 66:429-436. [PMID: 33837682 DOI: 10.1515/bmt-2020-0232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 03/12/2021] [Indexed: 11/15/2022]
Abstract
Materials used for dental crowns show a wide range of variety, and a dentist's choice can depend on several factors such as patient desires, esthetics, tooth factors, etc. One of the most important issues for implant surgery is the primary stability and it should be provided to minimize the risks of screw loosening, failed osseointegration, or nonunion. The current study aims to present the Finite Element Analysis (FEA)-based material selection strategy for a dental crown in terms of reducing the aforementioned risks of dental implants. A virtual surgery mandible model obtained using MIMICS software was transferred to the ANSYS and material candidates determined using CES software were compared using FEA. The results indicated that Zr02+Y2O3 (zirconia) has shown a 12.79% worse performance compared to Au83-88/Pt4-12/Pd4.5-6 alloy in terms of abutment loosening. On the other hand, zirconia is the most promising material for dental crowns in terms of the stability of the bone-implant complex. Therefore, it may show the best overall performance for clinical use. Moreover, as suggested in this study, a better outcome and more accurate predictions can be achieved using a patient-specific FEA approach for the material selection process.
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Affiliation(s)
| | - Murat Çolak
- Engineering Faculty, Bayburt University, Bayburt, Turkey
| | - Irfan Kaymaz
- Engineering Faculty, Erzurum Technical University, Erzurum, Turkey
| | - Fehim Findik
- Faculty of Technology, Sakarya Applied Sciences University, Sakarya, Turkey.,BIOENAMS Research Center, Sakarya University, Sakarya, Turkey
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Woodford SC, Robinson DL, Edelmann C, Mehl A, Röhrle O, Vee Sin Lee P, Ackland DC. Low-Profile Electromagnetic Field Sensors in the Measurement and Modelling of Three-Dimensional Jaw Kinematics and Occlusal Loading. Ann Biomed Eng 2021; 49:1561-1571. [PMID: 33409850 DOI: 10.1007/s10439-020-02688-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/04/2020] [Indexed: 11/30/2022]
Abstract
Dynamic occlusal loading during mastication is clinically relevant in the design and functional assessment of dental restorations and removable dentures, and in evaluating temporomandibular joint dysfunction. The aim of this study was to develop a modelling framework to evaluate subject-specific dynamic occlusal loading during chewing and biting over the entire dental arch. Measurements of jaw motion were performed on one healthy male adult using low-profile electromagnetic field sensors attached to the teeth, and occlusal anatomy quantified using an intra-oral scanner. During testing, the subject chewed and maximally compressed a piece of rubber between both second molars, first molars, premolars and their central incisors. The occlusal anatomy, rubber geometry and experimentally measured rubber material properties were combined in a finite element model. The measured mandibular motion was used to kinematically drive model simulations of chewing and biting of the rubber sample. Three-dimensional dynamic bite forces and contact pressures across the occlusal surfaces were then calculated. Both chewing and biting on the first molars produced the highest bite forces across the dental arch, and a large amount of anterior shear force was produced at the incisors and the second molars. During chewing, the initial tooth-rubber contact evolved from the buccal sides of the molars to the lingual sides at full mouth closure. Low-profile electromagnetic field sensors were shown to provide a clinically relevant measure of jaw kinematics with sufficient accuracy to drive finite element models of occlusal loading during chewing and biting. The modelling framework presented provides a basis for calculation of physiological, dynamic occlusal loading across the dental arch.
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Affiliation(s)
- Sarah C Woodford
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Dale L Robinson
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Cornelia Edelmann
- Centre of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Albert Mehl
- Centre of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Oliver Röhrle
- Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Stuttgart, Germany
| | - Peter Vee Sin Lee
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia
| | - David C Ackland
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia.
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18
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Pitta J, Hjerppe J, Burkhardt F, Fehmer V, Mojon P, Sailer I. Mechanical stability and technical outcomes of monolithic CAD/CAM fabricated abutment-crowns supported by titanium bases: An in vitro study. Clin Oral Implants Res 2020; 32:222-232. [PMID: 33258267 DOI: 10.1111/clr.13693] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 11/08/2020] [Accepted: 11/21/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To evaluate mechanical stability (survival and complication rates) and bending moments of different all-ceramic monolithic restorations bonded to titanium bases (hybrid abutment-crowns) or to customized titanium abutments compared to porcelain-fused-to-metal crowns (PFM) after thermo-mechanical aging. MATERIAL AND METHODS Sixty conical connection implants (4.3 mm-diameter) were divided in five groups (n = 12): PFM using gold abutment (GAbut-PFM), lithium disilicate crown bonded to customized titanium abutment (TAbut+LDS), lithium disilicate abutment-crown bonded to titanium base (TiBase+LDS), zirconia abutment-crown bonded to titanium base (TiBase+ZR), polymer-infiltrated ceramic-network (PICN) abutment-crown bonded to titanium base (TiBase+PICN). Simultaneous thermocycling (5°-55°C) and chewing simulation (1,200,000-cycles, 49 N, 1.67 Hz) were applied. Catastrophic and non-catastrophic events were evaluated under light microscope, and survival and complication rates were calculated. Specimens that survived aging were loaded until failure and bending moments were calculated. RESULTS Survival rates after aging were 100% (TAbut+LDS, TiBase+LDS), 91.7% (GA-PFM), 66.7% (TiBase+ZR) and 58.3% (TiBase+PICN) and differed among the groups (p = .006). Non-catastrophic events as screw loosening (GA-PFM) and loss of retention or micro-/macro-movement (TiBase groups) were observed. Complication rates varied among the groups (p < .001). TiBase+PICN had lower bending moment than all the other groups (p < .001). CONCLUSIONS Hybrid abutment-crowns made of lithium disilicate can be an alternative to PFM-based restorations, although concerns regarding the bonded interface between the titanium base and abutment-crown can be raised. PICN and zirconia may not be recommended due to its inferior mechanical and bonding outcomes, respectively. Titanium customized abutment with bonded lithium disilicate crown appears to be the most stable combination.
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Affiliation(s)
- João Pitta
- Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Jenni Hjerppe
- Departments of Oral and Maxillofacial Diseases, Helsinki University Hospital (HUH), Helsinki, Finland.,Department of Prosthodontics and Stomatognathic physiology, University of Turku, Turku, Finland
| | - Felix Burkhardt
- Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Vincent Fehmer
- Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Philippe Mojon
- Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Irena Sailer
- Division of Fixed Prosthodontics and Biomaterials, University Clinics for Dental Medicine, University of Geneva, Geneva, Switzerland
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19
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Ghodsi S, Tanous M, Hajimahmoudi M, Mahgoli H. Effect of aging on fracture resistance and torque loss of restorations supported by zirconia and polyetheretherketone abutments: An in vitro study. J Prosthet Dent 2020; 125:501.e1-501.e6. [PMID: 33248675 DOI: 10.1016/j.prosdent.2020.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 11/28/2022]
Abstract
STATEMENT OF PROBLEM New materials have been developed for digital processing, including implant abutments, but studies on their mechanical properties are lacking. PURPOSE The purpose of this in vitro study was to compare the effect of aging on the fracture resistance, failure mode, and torque loss of restorations made of zirconia and ceramic-reinforced polyetheretherketone (PEEK) abutments with titanium bases. MATERIAL AND METHODS Titanium-based PEEK and zirconia abutments were milled and veneered with composite resin or feldspathic porcelain in the form of maxillary first premolars (n=10). All the specimens were subjected to an aging process and were assessed after every 250 000 cycles under a stereomicroscope, and torque loss was recorded with an electronic torque meter. Fracture resistance was measured under static load (crosshead speed of 1 mm/min), and failure modes and final torque were determined. A t test was conducted for statistical analyses (α=.05). RESULTS The fracture resistance of the zirconia restorations was significantly greater than the PEEK-based restorations (P=.001). Torque losses were not significantly different after aging (P=.18); however, significant difference was recorded after the fracture test (P=.007). The effect of fracture load was significantly greater for the zirconia group (P<.001). Unlike with the zirconia group, the failure mode in the PEEK-based restorations was mainly adhesive and favorable (9 of 10 specimens). CONCLUSIONS Ceramic-reinforced PEEK abutments had acceptable resistance to fracture, a favorable failure mode, and successfully sustained the aging process.
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Affiliation(s)
- Safoura Ghodsi
- Associate professor, Dental Research Center, Dentistry Research Institute, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Michel Tanous
- Fellowship in Implant Dentistry, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
| | - Mohammadreza Hajimahmoudi
- Assistant professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Hoseinali Mahgoli
- Assistant professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
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Şensoy AT, Kaymaz I, Ertaş Ü. Biomechanical evaluation of a novel mandibular distraction osteogenesis protocol: an in-vitro validation and the practical use of the method. Comput Methods Biomech Biomed Engin 2020; 24:1-12. [PMID: 33241695 DOI: 10.1080/10255842.2020.1850704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/28/2020] [Accepted: 11/10/2020] [Indexed: 10/22/2022]
Abstract
The aim of this study was to optimize and experimentally validate the certain parameters affecting the operation success of Mandibular Distraction Osteogenesis (MDO). According to FEA results, the displacement of the samples showed 28.5% reduction as only the osteotomy line was separately optimized, and 64.2% less displacement was determined when the osteotomy line and the screw configuration were optimized together. In consistent with the FEA results, the samples showed 62% and 84.5% fewer displacement values, respectively. As a result, the MDO protocol suggested, which is validated by both numerical and experimental studies, offers promising outcomes for operation success.
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Affiliation(s)
- A T Şensoy
- Engineering Faculty, Samsun University, Samsun, Turkey
| | - I Kaymaz
- Mechanical Engineering Department, Erzurum Technical University, Erzurum, Turkey
| | - Ü Ertaş
- Oral & Maxillofacial Surgery Department, Atatürk University, Erzurum, Turkey
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21
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Karimi Dastgerdi A, Rouhi G, Dehghan MM, Farzad-Mohajeri S, Barikani HR. Linear Momenta Transferred to the Dental Implant-Bone and Natural Tooth-PDL-Bone Constructs Under Impact Loading: A Comparative in-vitro and in-silico Study. Front Bioeng Biotechnol 2020; 8:544. [PMID: 32596223 PMCID: PMC7303479 DOI: 10.3389/fbioe.2020.00544] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 05/06/2020] [Indexed: 11/16/2022] Open
Abstract
During dental trauma, periodontal ligament (PDL) contributes to the stability of the tooth-PDL-bone structure. When a dental implant is inserted into the bone, the dental implant-bone construct will be more prone to mechanical damage, caused by impact loading, than the tooth-PDL-bone construct. In spite of the prevalence of such traumas, the behavioral differences between these two constructs have not been well-understood yet. The main goal of this study was to compare the momentum transferred to the tooth-PDL-bone and dental implant-bone constructs under impact loading. First, mechanical impact tests were performed on six canine mandibles of intact (N = 3) and implanted (N = 3) specimens using a custom-made drop tower apparatus, from release heights of 1, 2, and 3 cm. Next, computed tomography-based finite element models were developed for both constructs, and the transferred momenta were calculated. The experimental results indicated that, for the release heights of 1, 2, and 3 cm, the linear momenta transferred to the dental implant-bone construct were 33.1, 31.0, and 27.5% greater than those of the tooth-PDL-bone construct, respectively. Moreover, results of finite element simulations were in agreement with those of the experimental tests (error <7.5%). This work tried to elucidate the effects of impact loading on the dental implant-bone and tooth-PDL-bone constructs using both in-vitro tests and validated in-silico simulations. The findings can be employed to modify design of the current generation of dental implants, based on the lessons one can take from the biomechanical behavior of a natural tooth structure.
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Affiliation(s)
| | - Gholamreza Rouhi
- Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Mohammad Mehdi Dehghan
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
- Institute of Biomedical Research, University of Tehran, Tehran, Iran
| | | | - Hamid Reza Barikani
- Dental Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
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22
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Lee H, Park S, Kwon KR, Noh G. Effects of cementless fixation of implant prosthesis: A finite element study. J Adv Prosthodont 2019; 11:341-349. [PMID: 31897273 PMCID: PMC6933050 DOI: 10.4047/jap.2019.11.6.341] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/01/2019] [Accepted: 12/10/2019] [Indexed: 11/25/2022] Open
Abstract
PURPOSE A novel retentive type of implant prosthesis that does not require the use of cement or screw holes has been introduced; however, there are few reports examining the biomechanical aspects of this novel implant. This study aimed to evaluate the biomechanical features of cementless fixation (CLF) implant prostheses. MATERIALS AND METHODS The test groups of three variations of CLF implant prostheses and a control group of conventional cement-retained (CR) prosthesis were designed three-dimensionally for finite element analysis. The test groups were divided according to the abutment shape and the relining strategy on the inner surface of the implant crown as follows; resin-air hole-full (RAF), resin-air hole (RA), and resin-no air hole (RNA). The von Mises stress and principal stress were used to evaluate the stress values and distributions of the implant components. Contact open values were calculated to analyze the gap formation of the contact surfaces at the abutment-resin and abutment-implant interfaces. The micro-strain values were evaluated for the surrounding bone. RESULTS Values reflecting the maximum stress on the abutment were as follows (in MPa): RAF, 25.6; RA, 23.4; RNA, 20.0; and CR, 15.8. The value of gap formation was measured from 0.88 to 1.19 µm at the abutmentresin interface and 24.4 to 24.7 µm at the abutment-implant interface. The strain distribution was similar in all cases. CONCLUSION CLF had no disadvantages in terms of the biomechanical features compared with conventional CR implant prosthesis and could be successfully applied for implant prosthesis.
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Affiliation(s)
- Hyeonjong Lee
- Department of Prosthodontics, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Soyeon Park
- School of Mechanical Engineering, Kyungpook National University, Daegu, Republic of Korea
| | - Kung-Rock Kwon
- Department of Prosthodontics, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea
| | - Gunwoo Noh
- School of Mechanical Engineering, Kyungpook National University, Daegu, Republic of Korea
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