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Oulghazi I, El Yamani A, Morchad B. Factors Influencing Vertical Radicular Fractures in Teeth Supported by Metallic Dental Core: A Scoping Review. Clin Cosmet Investig Dent 2024; 16:101-114. [PMID: 38665472 PMCID: PMC11044889 DOI: 10.2147/ccide.s458697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Purpose The aim of this work is to conduct a literature review to highlight all the parameters involved in sub-prosthetic radicular fractures of teeth supported by metallic dental core. Materials and Methods The following research was performed among published studies over the last 10 years in two PubMed/Medline and Scopus and supplemented by manual searching within the bibliographies. The search was restricted to publications in English and French. Results Out of the 1464 articles initially identified, 18 studies met our inclusion criteria and were subsequently included in the literature review. These consisted of eight Finite Element Analysis Studies, two Retrospective Studies and one Randomized Controlled Trial. The results of this review show that radicular fractures are influenced by several variables, including predisposition, with maxillary premolars and mandibular molars being the most commonly affected teeth. Intracanal preparation can induce crack formation, leading to localized high stress concentrations. Increased ferrule height to 2 mm significantly enhances dental fracture resistance. Using high modulus of elasticity alloys results in nearly complete stress transmission to dentin due to their limited deformability and absorption capacity. The highest fracture resistance is achieved when posts are sealed using resin-modified glass-ionomer cement. Longer posts may be preferable to prevent vertical fractures. Additionally, occlusal factors, through repetitive stresses, contribute to crack propagation from surface defects, a phenomenon termed fatigue fracture. Conclusion These findings have significant implications. Practitioners should be aware of the predisposition of certain teeth, the importance of preserving the ferrule effect, the choice of root post materials, post Cement Material and the role of occlusal forces in managing and preventing vertical root fractures.
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Affiliation(s)
- Ichraq Oulghazi
- Prosthodontics Department, Mohammed V University, Rabat, Morocco
| | - Amal El Yamani
- Prosthodontics Department, Mohammed V University, Rabat, Morocco
| | - Bouabid Morchad
- Prosthodontics Department, Mohammed V University, Rabat, Morocco
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Feng J, Chai M, Zhang K, Liu J, Li X. Influence of restorative materials on the mechanical properties of maxillary first molars with different degrees of cryptic fractures and defects: A finite element analysis. Dent Mater J 2024; 43:97-105. [PMID: 38104999 DOI: 10.4012/dmj.2023-151] [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] [Indexed: 12/19/2023]
Abstract
This study aimed to apply finite element analysis to evaluate the effects of pile materials with different elastic moduli and cement materials on the stress distribution between the remaining tooth tissue and cryptic fracture defects. A three-dimensional finite element model was established for 20 maxillary first molars with hidden fissures and mesial tongue-tip defects. Two levels of hidden cracks and three types of pile and adhesive materials were used in the design. The stress distribution and maximum stress peak in the remaining tooth tissue and crack defects were determined by simulating the normal bite, maximum bite, and lateral movement forces. When titanium posts, zinc phosphate binders, and porcelain crowns were used to repair the two types of deep cracked teeth, the maximum principal stress at the crack and dentin was the smallest. As the crack depth increased, the maximum principal stress of the residual dentin and crack defects increased.
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Affiliation(s)
- Jiaying Feng
- Department of Oral Clinical Medicine, School of Stomatology, Jinzhou Medical University
| | - Mingzhu Chai
- Department of Oral Clinical Medicine, School of Stomatology, Jinzhou Medical University
| | - Ke Zhang
- Department of Oral Clinical Medicine, School of Stomatology, Jinzhou Medical University
| | - Jinjian Liu
- Department of Oral Clinical Medicine, School of Stomatology, Jinzhou Medical University
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Zhong Q, Huang Y, Zhang Y, Song Y, Wu Y, Qu F, Wang S, Xu C. Finite element analysis of maxillary first molar with a 4-wall defect and 1.5-mm-high ferrule restored with fiber-reinforced composite resin posts and resin core: The number and placement of the posts. J Prosthet Dent 2024; 131:75-91. [PMID: 35249741 DOI: 10.1016/j.prosdent.2022.01.029] [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: 09/23/2021] [Revised: 01/14/2022] [Accepted: 01/19/2022] [Indexed: 12/01/2022]
Abstract
STATEMENT OF PROBLEM Whether fiber-reinforced composite (FRC) posts should be inserted in root canals to restore teeth with multiple roots remains unclear. PURPOSE The purpose of this finite element analysis (FEA) study was to determine the optimal use of FRC posts in an endodontically treated maxillary first molar with a 4-wall defect and 1.5-mm-high ferrule. MATERIAL AND METHODS Eight different models of a maxillary first molar were established: no post (NP), post in palatal root (P), post in distobuccal root (DB), post in mesiobuccal root (MB), posts in palatal root and distobuccal root (P+DB), posts in palatal root and mesiobuccal root (P+MB), posts in 2 buccal roots (DB+MB), and posts in all roots (P+DB+MB). Two types of loading were applied: a force of 800 N parallel to the long axis of the tooth to simulate the vertical masticatory force and another force of 225 N at 45 degrees to the long axis of the tooth to simulate the lateral masticatory force. The equivalent stresses on the external surfaces of the tooth tissue, the internal surfaces of the root canals and in the posts, as well as the maximal shear stresses on the post-core interface and the core-dentin interface, were calculated with FEA. RESULTS All the models showed similar maximal equivalent stress values on the external surfaces of the tooth tissue, and stress concentrations were found at the cervical and furcation area. On the internal surfaces of root canals, an increase of equivalent stress at the middle third of the canals with posts and a decrease at the cervical third were observed. Under vertical loading, the P+DB+MB group showed the largest equivalent stress in the post (76.45 MPa in the palatal post), the DB+MB group showed the largest shear stress on the post-core interface (19.02 MPa), and the MB group showed the largest shear stress on the core-dentin interface (12.07 MPa). Under lateral loading, the P+DB+MB group showed the largest equivalent stress in the post (60.11 MPa in the mesiobuccal post) and the largest shear stress on the post-core interface (13.48 MPa) and the DB group showed the largest shear stress on the core-dentin interface (21.03 MPa). CONCLUSIONS One post in the palatal canal was found to be appropriate for the FRC post and resin core restoration of a maxillary first molar with a 4-wall defect and 1.5-mm-high ferrule. An additional post in the mesiobuccal canal could help disperse lateral occlusal force and improve retention of the restoration.
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Affiliation(s)
- Qi Zhong
- Graduate student, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology, Shanghai, PR China
| | - Yujie Huang
- Graduate student, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology, Shanghai, PR China
| | - Yifan Zhang
- Graduate student, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology, Shanghai, PR China
| | - Yingshuang Song
- Resident, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology, Shanghai, PR China
| | - Yaqin Wu
- Doctoral student, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology, Shanghai, PR China
| | - Fang Qu
- Resident, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology, Shanghai, PR China
| | - Shaohai Wang
- Professor, Department of Stomatology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, PR China
| | - Chun Xu
- Professor, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology, Shanghai, PR China.
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Gontijo IG, Ferretti MA, Caldas RA, Pecorari VGA, França FMG, Oliveira LKN, Aguiar FHB. Biomechanical behavior of weakened roots restored with custom-made post-and-cores of glass fiber and polyetheretherketone. J Prosthodont 2023; 32:807-814. [PMID: 36482016 DOI: 10.1111/jopr.13628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To evaluate the influence of post type and mechanical aging on compression force resistance, fracture pattern, and stress distribution in weakened roots. MATERIALS AND METHODS Bovine roots were endodontically treated and widened-and randomly divided into 8 groups (n = 10) according to post type (prefabricated glass fiber post and customized anatomic glass fiber post, milled glass fiber post-and-core, and milled polyetheretherketone post-and-core) and mechanical aging (without and with mechanical aging). Three hundred thousand cycles of mechanical fatigue were performed and compression force resistance (N) was analyzed by two-way ANOVA and Tukey test (α = 0.05). Fracture patterns were reported and stress distribution was analyzed by finite elements analysis. RESULTS There was a significant effect of post type (p = 0.032) and mechanical aging (p = 0.009), but no double interaction (p = 0.879). Higher values were recorded in the milled glass fiber and polyetheretherketone post-and-core groups compared to the prefabricated glass fiber post groups, and no significant difference was found among anatomic glass fiber post groups and other groups. Reparable fractures were predominant in the milled glass fiber and polyetheretherketone post-and-core groups. Prefabricated glass fiber posts and milled polyetheretherketone post-and-cores showed similar stress distribution. CONCLUSIONS Post type and mechanical aging influence the compression force resistance and fracture pattern of weakened roots. Milled glass fiber and polyetheretherketone post-and-cores exhibited higher compression force resistance and more reparable fractures compared to prefabricated glass fiber posts. Prefabricated glass fiber posts and milled polyetheretherketone post-and-cores showed similar stress distribution.
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Affiliation(s)
- Isabela G Gontijo
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
| | - Marcela A Ferretti
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
| | - Ricardo A Caldas
- Department of Prosthodontics, Federal University of Santa Catarina - UFSC, Florianópolis, SC, Brazil
| | - Vanessa G A Pecorari
- Department of Dental Materials, Paulista University - UNIP, São Paulo, SP, Brazil
| | - Fabiana M G França
- Department of Restorative Dentistry, São Leopoldo Mandic School of Dentistry - SLMANDIC, Campinas, SP, Brazil
| | - Lorena K N Oliveira
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
| | - Flávio H B Aguiar
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
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Lima MO, Ferretti MA, Caldas RA, Barão VAR, França FMG, Lima DANL, Martins LR, Aguiar FHB. Application of polyetheretherketone (PEEK) posts: evaluation of fracture resistance and stress distribution in the root: in vitro and finite element analyses. Braz Oral Res 2023; 37:e047. [PMID: 37255067 DOI: 10.1590/1807-3107bor-2023.vol37.0047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 12/06/2022] [Indexed: 06/01/2023] Open
Abstract
To evaluate the feasibility of using a milled polyetheretherketone (PEEK) post and core in endodontically treated teeth with or without a ferrule. Sixty bovine tooth roots were endodontically treated followed by cementation of intraradicular retainers (IR), according to each experimental group: a) non-ferrule glass fiber post (f0FP); b) 2-mm-ferrule glass fiber post (f2FP); c) non-ferrule resized glass fiber post (f0PR); d) 2-mm-ferrule resized glass fiber post (f2PR); e) non-ferrule PEEK post and core (f0PPC); and f) 2-mm-ferrule PEEK post and core (f2PPC). Metal crowns were made and cemented. A periodontal ligament was simulated using polyether. A force was applied to the palatine portion of each sample at 45°, until fracture. Fracture resistance data were submitted to two-way ANOVA and Tukey's test (α = 0.05). Three-dimensional digital models were developed to calculate the tensions formed in the root using finite element analysis. Models of glass fiber posts and PEEK posts and cores were evaluated with or without a ferrule. The results were analyzed by the Mohr-Coulomb criterion. The type of IR was not influenced by fracture strength (p = 0.243). There were significant statistical differences among the remaining factors. Ferrule groups had greater fracture resistance, and the failure mode of teeth with a ferrule was more catastrophic than the non-ferrule group. A ferrule increases fracture resistance and influences failure mode; the PEEK post and core did not modify the biomechanics of endodontically treated teeth, and resembled the glass fiber post results. The crack initiation point differed between the ferrule and non-ferrule groups.
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Affiliation(s)
- Michele Oliveira Lima
- Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Restorative Dentistry, Piracicaba, SP, Brazil
| | - Marcela Alvarez Ferretti
- Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Restorative Dentistry, Piracicaba, SP, Brazil
| | - Ricardo Armini Caldas
- Universidade Federal de Santa Catarina - UFSC, Department of Dentistry, Florianópolis, SC, Brazil
| | - Valentim Adelino Ricardo Barão
- Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Prosthodontics and Periodontology, Piracicaba, SP, Brazil
| | | | - Débora Alves Nunes Leite Lima
- Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Restorative Dentistry, Piracicaba, SP, Brazil
| | - Luís Roberto Martins
- Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Restorative Dentistry, Piracicaba, SP, Brazil
| | - Flávio Henrique Baggio Aguiar
- Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Restorative Dentistry, Piracicaba, SP, Brazil
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Finite Element Analysis of the Mechanical Performance of Non-Restorable Crownless Primary Molars Restored with Intracoronal Core-Supported Crowns: A Proposed Treatment Alternative to Extraction for Severe Early Childhood Caries. J Clin Med 2023; 12:jcm12051872. [PMID: 36902658 PMCID: PMC10003140 DOI: 10.3390/jcm12051872] [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: 01/23/2023] [Revised: 02/13/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023] Open
Abstract
Early childhood caries (ECC) involve extensive coronal tooth structure loss, and tooth reconstruction remains highly challenging. To fulfill preclinical assessment, the present study investigated the biomechanics of non-restorable crownless primary molars that were restored by stainless steel crowns (SSC) using different composite core build-up materials. Computer-aided design-integrated 3D finite element and modified Goodman fatigue analyses were performed to determine stress distribution, risk of failure, fatigue life and dentine-material interfacial strength for the restored crownless primary molars. A dual-cured resin composite (MultiCore Flow), a light-cured bulk-fill resin composite (Filtek Bulk Fill posterior), a resin-modified glass-ionomer cement (Fuji II LC) and a nano-filled resin-modified glass-ionomer cement (NRMGIC; Ketac N100) were used as core build-up composite materials in the simulated models. The finite element analysis showed that types of core build-up materials affected the maximum von Mises stress only in the core materials (p-value = 0.0339). NRMGIC demonstrated the lowest von Mises stresses and revealed the highest minimum safety factor. The weakest sites were along the central grooves regardless of type of material, and the ratio of shear bond strength to maximum shear stress at the core-dentine interface of the NRMGIC group was lowest among the tested composite cores. However, all groups provided lifetime longevity from the fatigue analysis. In conclusion, core build-up materials differentially influenced the von Mises stress (magnitude and distribution) and the safety factor in crownless primary molars restored with core-supported SSC. However, all materials and the remaining dentine of crownless primary molars provided lifetime longevity. The reconstruction by core-supported SSC, as an alternative to tooth extraction, may successfully restore non-restorable crownless primary molars without unfavorable failures throughout their lifespan. Further clinical studies are required to evaluate the clinical performance and suitability of this proposed method.
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Gontijo IG, Ferretti MA, Monteiro LC, Caldas RA, Pecorari VGA, França FMG, Aguiar FHB. Influence of alveolar bone height on the biomechanical behavior of roots restored with custom-made posts-and-cores. J ESTHET RESTOR DENT 2023; 35:677-686. [PMID: 36602235 DOI: 10.1111/jerd.13010] [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: 11/08/2022] [Revised: 12/16/2022] [Accepted: 12/23/2022] [Indexed: 01/06/2023]
Abstract
OBJETIVE This study evaluated the influence of alveolar bone height and post type on compressive force resistance, fracture pattern, and stress distribution in endodontically treated teeth. MATERIALS AND METHODS Bovine roots were endodontically treated and divided into eight groups (n = 10) according to alveolar bone height (normal alveolar bone and alveolar bone loss - 2 and 5 mm from the margin of the crown, respectively) and post type (prefabricated glass fiber post, anatomic glass fiber post, customized milled glass fiber post-and-core and customized milled polyetheretherketone (PEEK) post-and-core). Mechanical fatigue was simulated (300.000 cycles/50 N/1.2 Hz). Compression force resistance (N) was analyzed by two-way ANOVA and Tukey test (α = 0.05). Fracture patterns were described as percentages. Stress distribution was analyzed by finite element analysis. RESULTS Significant diferences were found for alveolar bone height (P < 0.0001): normal alveolar bone groups showed higher mean values of compression force resistance compared to alveolar bone loss groups, while no significant differences were found for post type (P = 0.4551), and there was no double interaction between them (P = 0.5837). Reparable fractures were more predominant in normal alveolar bone groups, especially in the milled glass fiber and PEEK post-and-core groups. Stress distribution was similar in groups with prefabricated glass fiber posts and milled PEEK posts-and-cores, and the alveolar bone loss condition significantly increased stress concentration and strain values, mainly on apical dentin. CONCLUSIONS Alveolar bone loss due to physiological aging and/or periodontal disease may lead to increased risk of restored tooth failure, although milled glass fiber and PEEK posts-and-cores provide more reparable fractures. CLINICAL SIGNIFICANCE Custom-made glass fiber and PEEK post-and-cores are interesting options, since they enable clinicians to work with a single-body post-and-core system that avoid several materials interfaces and fits well in the root canal provided promising results to improve the failure behavior of restored roots, as they offer more reparable fractures even in situations of alveolar bone loss.
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Affiliation(s)
- Isabela Guerra Gontijo
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, São Paulo, Brazil
| | - Marcela Alvarez Ferretti
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, São Paulo, Brazil
| | - Lara Christie Monteiro
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, São Paulo, Brazil
| | - Ricardo Armini Caldas
- Department of Prosthodontics, Federal University of Santa Catarina - UFSC, Florianópolis, Santa Catarina, Brazil
| | | | | | - Flávio Henrique Baggio Aguiar
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, São Paulo, Brazil
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Gong Q, Huang L, Luo J, Zhang Y, Meng Q, Quan J, Tong Z. The practicability of different preparation of mandibular molar restored by modified endocrown with intracanal extension: Computational analysis using finite element models. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 226:107178. [PMID: 36242865 DOI: 10.1016/j.cmpb.2022.107178] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 10/01/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE Post-core-crown (PCC) and endocrown are two common restorative methods for severely damaged molars, but exhibit disadvantages. This study aimed to explore the practicability of modified endocrown with a 2 mm intracanal extension (MED) to restore defective teeth using finite element analysis (FEA). METHODS Five groups of numerical models of mandibular molars restored by three MEDs, a PCC, and a routine endocrown after root canal treatment were devised by FEA software. We constructed 4 mm, 3 mm, and 2 mm thickness of MED restorations to restore mandibular molars that were prepared to 1 mm, 2 mm, and 3 mm from the cemento-enamel junction (CEJ). Furthermore, PCC and routine endocrown were used to compare the stress distribution with MED. Lithium disilicate glass-ceramics (EMAX) and resin nanoceramics (LU) were considered restorative materials, and a vertical load of 600 N and an oblique load of 200 N were applied to the restorations. RESULTS In three MEDs by LU, 2 mm thickness of restoration generated the highest stress on prepared teeth, while the thickness of EMAX did not significantly influence the stress value. MED by LU generated higher stress around the CEJ, and reduced the stress on the middle and lower root compared to MEDs by EMAX, PCC by EMAX, and PCC by LU. MED by EMAX caused lower stress around the CEJ, and generated higher stress in the chamber walls after extended root canals compared with MED by LU, endocrowns by LU, and endocrowns by EMAX. There was an evident stress concentration at the last but one layer, which was a thin area of the tooth root in all restorative models. CONCLUSIONS The use of modified endocrown may be considered an effective restorative method to restore defective mandibular molar, but suitable restorative material must be selected based on the tooth preparation method and deficiencies in the tooth structure.
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Affiliation(s)
- Qimei Gong
- Hosiptal of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Luo Huang
- Hosiptal of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Junpan Luo
- Hosiptal of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yuejiao Zhang
- Hosiptal of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Qingzhen Meng
- Hosiptal of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jingjing Quan
- Hosiptal of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhongchun Tong
- Hosiptal of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
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Comparative Evaluation of the Effect of Core Type and Antirotational Post on Stress Distribution in an Endodontically Treated Maxillary First Molar: FEA. Int J Dent 2022; 2022:4336980. [PMID: 35601814 PMCID: PMC9117046 DOI: 10.1155/2022/4336980] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/06/2022] [Accepted: 04/12/2022] [Indexed: 11/23/2022] Open
Abstract
Background This study aims to analyze and compare the stress distribution in an endodontically treated maxillary first molar restored with various post and core systems and assess the benefit of the presence of an antirotational post and the effect of its length using finite element analysis. Materials and Methods Five 3D models of maxillary first molar restored with variable designs of post and core were constructed using CT scanning and information obtained from textbook and FEM software. Variables were types of core, presence or absence of an antirotational post, and length of the antirotational post. A load of 480 (N) vertically and a load of 240 (N) with 45° to the occlusal plane were applied. Results were analyzed using 3D von Mises criteria. Results The results showed that the most homogeneous stress distribution pattern along with dentin and the post-core system was observed in the model with one main post in the palatal canal and in the model with a two-piece core and one main post in the palatal canal and shorter antirotational post in the distal-buccal canal. However, models with one-piece core and antirotational post (either the same length or shorter than the main post) in the distal-buccal canal had the most stress concentration sites. Conclusion In this study, it was found that the presence of an antirotational post, its length, and type of core affected the distribution of stress along the dentin and post-core system. This study indicated that if the antirotational post is considered in the post-core design, it is better to use a two-piece core type due to more homogeneous stress distribution along the dentin and post-core system.
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The Influence of Cement Layer Thickness on the Stress State of Metal Inlay Restorations-Photoelastic Analysis. MATERIALS 2021; 14:ma14030599. [PMID: 33525369 PMCID: PMC7866133 DOI: 10.3390/ma14030599] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/18/2021] [Accepted: 01/25/2021] [Indexed: 12/16/2022]
Abstract
The successful restoration of teeth requires a good connection between the inlay and natural tissue. A strong bond may improve retention and reinforce tooth structure. The purpose of this study was to evaluate the influence of cement layer thickness on contraction stress generated during photopolymerization, and to determine the changes in stress state of the cement occurring during aging in water (over 84 days). Two cements were used: resin composite cement (NX3) and self-adhesive resin cement (Maxcem Elite Chroma). A cylindrical sample made of CuZn alloy was used to imitate the inlay. The stress state was measured by photoelastic analysis. The contraction stress of the inlay restoration was calculated for cement layer thicknesses of 25 µm, 100 µm, 200 µm, and 400 µm. For both tested materials, the lowest contraction stress was observed for the thinnest layer (25 µm), and this increased with thickness. Following water immersion, a significant reduction in contraction stress was observed due to hygroscopic expansion. Applying a thin layer (approximately 25 µm) of composite and self-adhesive resin cements resulted in high levels of expansion stresses (over −6 MPa) after water aging.
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YU QIUDONG, ZHENG SHUXIAN, WANG WEIZHEN. CUSTOMIZED POST-AND-CORE DESIGN AND STRESS ANALYSIS FOR POSTERIOR TOOTH PROSTHESIS. J MECH MED BIOL 2019; 19:1940038. [DOI: 10.1142/s0219519419400384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2023]
Abstract
A post-and-core crown is widely used in prosthetic dentistry; however, in clinical treatment, it easily causes root fracture and tooth penetration. To address these problems, this study aimed to present a customized post-and-core design for the posterior tooth implant. First, a residual tooth and its root canal were reconstructed. Then, the root canal surface was extracted, the surface curvature and length parameters were defined, and the customized post-and-core design was developed. Finally, the tooth, root canal, and post-and-core with different implant lengths in five masticatory directions were analyzed using finite element analysis to evaluate the stress distribution. The results showed that, with the similar shape of the post-and-core structure and the root canal, the tooth stress trend was uniform. When the length of the post-and-core structure [Formula: see text] was 0[Formula: see text]mm, that is, it was two thirds of the root canal length, the root canal stress was minimum. Therefore, the customized design of the post-and-core structure could well adapt to any kind of root canal, and the length of the post-and-core structure [Formula: see text] provided guidance for the post-and-core crown prosthesis in clinic.
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Affiliation(s)
- QIUDONG YU
- Department of Computer and Information Engineering, Tianjin Agriculture University, Tianjin 300384, P. R. China
- College of Water Resources & Civil Engineering, China Agricultural University, Beijing 100083, P. R. China
| | - SHUXIAN ZHENG
- Tianjin Key Laboratory of Equipment Design and Manufacturing Technology, Tianjin University, Tianjin 300354, P. R. China
| | - WEIZHEN WANG
- Tianjin Key Laboratory of Equipment Design and Manufacturing Technology, Tianjin University, Tianjin 300354, P. R. China
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KUROKAWA H, SHIRATSUCHI K, SUDA S, NAGURA Y, SUZUKI S, MORITAKE N, YAMAUCHI K, MIYAZAKI M. Effect of light irradiation and primer application on polymerization of selfadhesive resin cements monitored by ultrasonic velocity. Dent Mater J 2018; 37:534-541. [DOI: 10.4012/dmj.2017-215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Hiroyasu KUROKAWA
- Department of Operative Dentistry, Nihon University School of Dentistry
| | - Koji SHIRATSUCHI
- Department of Operative Dentistry, Nihon University School of Dentistry
| | - Shunichi SUDA
- Department of Operative Dentistry, Nihon University School of Dentistry
| | - Yuko NAGURA
- Department of Operative Dentistry, Nihon University School of Dentistry
| | - Soshi SUZUKI
- Department of Operative Dentistry, Nihon University School of Dentistry
| | - Nobuyuki MORITAKE
- Department of Operative Dentistry, Nihon University School of Dentistry
| | - Kabun YAMAUCHI
- Department of Operative Dentistry, Nihon University School of Dentistry
| | - Masashi MIYAZAKI
- Department of Operative Dentistry, Nihon University School of Dentistry
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13
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Takenaka H, Ouchi H, Sai K, Kawamoto R, Murayama R, Kurokawa H, Miyazaki M. Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self-adhesive resin cement. Eur J Oral Sci 2015; 123:369-374. [DOI: 10.1111/eos.12205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2015] [Indexed: 11/26/2022]
Affiliation(s)
- Hirotaka Takenaka
- Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
| | - Hajime Ouchi
- Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
| | - Keiichi Sai
- Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
| | - Ryo Kawamoto
- Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
| | - Ryosuke Murayama
- Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
| | - Hiroyasu Kurokawa
- Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
| | - Masashi Miyazaki
- Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
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A 3-dimensional finite element analysis of the restoration of the maxillary canine with a complex zirconia post system. J Prosthet Dent 2014; 112:1406-15. [PMID: 24993379 DOI: 10.1016/j.prosdent.2014.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 05/21/2014] [Accepted: 05/21/2014] [Indexed: 11/23/2022]
Abstract
STATEMENT OF PROBLEM Zirconia posts exhibit high strength and toughness, but reliable bonding with the resin core is difficult to attain. The use of a ferrule has been found to improve stress distribution in the root of endodontically treated teeth. PURPOSE The purpose of this finite element analysis study was to measure the stress distribution in the post-core system and root structure of a maxillary canine. MATERIAL AND METHODS A right maxillary canine was embedded and subjected to a micro-computed tomography scan. Three-dimensional dynamic scan data were then transformed, and a finite element model of 4 dentin ferrule heights was designed with zirconia posts and heat-pressed glass ceramics for a complete crown restoration. Von Mises stresses were determined by applying a 300 N static load to the middle of the lingual surface of the crown. RESULTS When the ferrule height increased from 0 to 3 mm, the maximum von Mises stress of the zirconia post decreased from 196 to 149 MPa, and that on the zirconia post-dentin interface decreased from 174 to 132 MPa. The maximum von Mises stress decreased from 39.8 to 32.5 MPa in the apical root and from 59.5 to 49.9 MPa in the mid-root when the ferrule height increased from 0 to 3 mm. CONCLUSIONS Increased ferrule height is associated with reduced von Mises stress in the zirconia post and the post-dentin interface, with an apparent shift of von Mises stress to the root cervical area from the mid-root and the apex.
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