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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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Montoya C, Baraniya D, Chen T, Al-Hebshi NN, Orrego S. The effect of dental material type and masticatory forces on periodontitis-derived subgingival microbiomes. Biofilm 2024; 7:100199. [PMID: 38800100 PMCID: PMC11127099 DOI: 10.1016/j.bioflm.2024.100199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 04/19/2024] [Accepted: 05/04/2024] [Indexed: 05/29/2024] Open
Abstract
Restorative dental materials can frequently extend below the gingival margin, serving as a potential haven for microbial colonization, and altering the local oral microbiome to ignite infection. However, the contribution of dental materials on driving changes of the composition of the subgingival microbiome is under-investigated. This study evaluated the microbiome-modulating properties of three biomaterials, namely resin dental composites (COM), antimicrobial piezoelectric composites (BTO), and hydroxyapatite (HA), using an optimized in vitro subgingival microbiome model derived from patients with periodontal disease. Dental materials were subjected to static or cyclic loading (mastication forces) during biofilm growth. Microbiome composition was assessed by 16S rRNA gene sequencing. Dysbiosis was measured in terms of subgingival microbial dysbiosis index (SMDI). Biomaterials subjected to cyclic masticatory loads were associated with enhanced biofilm viability except on the antibacterial composite. Biomaterials held static were associated with increased biofilm biomass, especially on HA surfaces. Overall, the microbiome richness (Chao index) was similar for all the biomaterials and loading conditions. However, the microbiome diversity (Shannon index) for the HA beams was significantly different than both composites. In addition, beta diversity analysis revealed significant differences between composites and HA biomaterials, and between both loading conditions (static and cyclic). Under static conditions, microbiomes formed over HA surfaces resulted in increased dysbiosis compared to composites through the enrichment of periopathogens, including Porphyromonas gingivalis, Porphyromonas endodontalis, and Fretibacterium spp., and depletion of commensals such as Granulicatella and Streptococcus spp. Interestingly, cyclic loading reversed the dysbiosis of microbiomes formed over HA (depletion of periopathogenes) but increased the dysbiosis of microbiomes formed over composites (enrichment of Porphyromonas gingivalis and Fusobacterim nucleatum). Comparison of species formed on both composites (control and antibacterial) showed some differences. Commercial composites enriched Selenomonas spp. and depleted Campylobacter concisus. Piezoelectric composites effectively controlled the microbiome viability without significantly impacting the species abundance. Findings of this work open new understandings of the effects of different biomaterials on the modulation of oral biofilms and the relationship with oral subgingival infections.
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Affiliation(s)
- Carolina Montoya
- Smart Biomaterials Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Divyashri Baraniya
- Oral Microbiome Research Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Tsute Chen
- Department of Microbiology, Forsyth Institute, Cambridge, MA, USA
| | - Nezar Noor Al-Hebshi
- Oral Microbiome Research Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Santiago Orrego
- Smart Biomaterials Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, USA
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Zuo Q, Li A, Teng H, Liu Z. Influence of internal angle and shape of the lining on residual stress of Class II molar restorations. Comput Methods Biomech Biomed Engin 2024; 27:680-688. [PMID: 38229450 DOI: 10.1080/10255842.2024.2301792] [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: 09/19/2023] [Accepted: 12/28/2023] [Indexed: 01/18/2024]
Abstract
Polymerization shrinkage is a major side effect of resin composite materials that affects the success and longevity of caries restorations. This study was to analyze the effect of the internal angle and shape of the lining on the shrinkage residual stress of dental restorations in Class II mesio-occlusal-distal (MOD) cavities through finite element analysis (FEA). A 3D reconstructed model of a human mandibular first molar was created from micro-CT images, and then the tooth was prepared as a Class II MOD cavity. 3D models of four regular internal corner shapes of Class II MOD cavities with different internal angles of lining and one 90° filleted corner model were created. The thermal expansion technique was applied to approximate the shrinkage impact of composite resin polymerization in the FE software ABAQUS. Von Mises stress was taken as a metric. The results showed that the level of residual stresses in the Class II MOD cavities was greatly dependent on the internal angle of the lining. The maximum von Mises stress in tooth tissue decreased as the internal angle of the lining increased. The internal shapes of the lining had no obvious effect on the stress, and the filleted corner model had less stress. This lining strategy is appropriate for Class II MOD cavities with serious loss of tooth tissue.
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Affiliation(s)
- Qianqian Zuo
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, China
- Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin, China
| | - Annan Li
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, China
- Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin, China
| | - Haidong Teng
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, China
- Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin, China
| | - Zhan Liu
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, China
- Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin, China
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4
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Jung MK, Jeon MJ, Kim JH, Son SA, Park JK, Seo DG. Comparison of the stress distribution in base materials and thicknesses in composite resin restorations. Heliyon 2024; 10:e25040. [PMID: 38333812 PMCID: PMC10850536 DOI: 10.1016/j.heliyon.2024.e25040] [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: 07/22/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/10/2024] Open
Abstract
Resin-based composite materials are commonly used for restorations, but their dimensional changes during the polymerization could cause various clinical problems. This study evaluated the influence of a base of different materials and thicknesses on the stress magnitude and distribution in a second maxillary premolar with an MOD resin composite restoration using three-dimensional finite element analysis. A sound tooth without cavity was considered as the control group (ST), and another group was restored with composite resin without applying a base material in a MOD cavity (CR). The other three groups were restored with composite resin along with the following base materials: glass ionomer cement, low-viscosity resin, and tricalcium silicate, respectively (CR-GIC, CR-LR, and CR-TS). These three groups were further divided into two subgroups according to the thickness of the base layer: thin (0.5 mm) and thick (1.0 mm). The stress distribution was compared using the maximum principal stress after polymerization shrinkage and vertical loading with 600 N on the occlusal surface. Group ST showed the lowest stress value, and its stress propagation was confined to outer enamel surfaces only. Group CR demonstrated the highest stress distribution in the tooth-restoration interface with increased failure risk on marginal areas. The thin and thick subgroups of the three groups with a base layer had lower stress levels than Group CR. The base materials reduced the marginal stress caused by polymerization shrinkage of composite resin in MOD cavities. Different base materials and thicknesses did not affect the stress distribution.
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Affiliation(s)
- Min-Kwan Jung
- Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Mi-Jeong Jeon
- Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
- Department of Conservative Dentistry, College of Dentistry, Gangnam Severance Hospital, Yonsei University, Seoul, Republic of Korea
| | - Jae-Hoon Kim
- Department of Dental Education, Dental Research Institute, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Sung-Ae Son
- Department of Conservative Dentistry, Dental Research Institute, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Jeong-Kil Park
- Department of Conservative Dentistry, Dental Research Institute, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Deog-Gyu Seo
- Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
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He X, Zhang S, Zhong Y, Huang X, Liu F, He J, Mai S. A low-shrinkage-stress and anti-bacterial adherent dental resin composite: physicochemical properties and biocompatibility. J Mater Chem B 2024; 12:814-827. [PMID: 38189164 DOI: 10.1039/d3tb01556d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Polymerisation shrinkage and biofilm accumulation are the two main problems associated with dental resin composites (DRCs) that induce secondary caries, which can cause restoration failure. Polymerisation shrinkage can lead to microleakage gaps between the tooth and the DRCs, causing the aggregation of bacteria and development of secondary caries. Reducing the shrinkage stress (SS) and improving the resistance to bacterial adhesion have always been the focus of this field in modifying DRCs. A thiol-ene resin system can effectively reduce the polymerisation SS via its step-growth mechanism for delaying the gel point. Fluorinated compounds can reduce the surface free energies, thereby reducing bacterial adhesion. Thus, in this study, a range of mass fractions (0, 10, 20, 30, and 40 wt%) of a fluorinated thiol-ene resin system were added to a fluorinated dimethacrylate resin system/tricyclo decanedimethanol diacrylate to create a fluorinated methacrylate-thiol-ene ternary resin matrix. DRCs were prepared using the obtained ternary resin matrix, and their physical and chemical properties, effect on bacterial adhesion, and biocompatibility were investigated. The results demonstrated that the volumetric shrinkage and SS of the DRCs were reduced with no reduction in conversion degree even after the thiol-ene resin system was added. All DRC-based fluorinated resin systems exhibited an excellent anti-bacterial adhesion effect, as evidenced by the colony-forming unit counts, live/dead bacterial staining, and crystal violet staining tests against Streptococcus mutans (S. mutans). The genetic expressions associated with the bacterial adhesion of S. mutans were substantially affected after being cultured with fluorinated DRCs. All fluorinated DRCs demonstrated good biocompatibility through the in vitro cytotoxicity test and live/dead staining images of the L-929 cells. The above results illustrate that the DRCs based on the fluorinated methacrylate-thiol-ene resin matrix can be potentially applied in clinical practice due to their low SS and anti-bacterial adhesion effect.
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Affiliation(s)
- Xinlin He
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China.
- Guanghua School of Stomatology, Sun Yat-sen University, Guangdong, 510055, People's Republic of China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China
| | - Shengcan Zhang
- College of Materials Science and Engineering, South China University of Technology, Guangzhou, Guangdong, 510641, People's Republic of China.
| | - Yewen Zhong
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China.
- Guanghua School of Stomatology, Sun Yat-sen University, Guangdong, 510055, People's Republic of China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China
| | - Xiangya Huang
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China.
- Guanghua School of Stomatology, Sun Yat-sen University, Guangdong, 510055, People's Republic of China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China
| | - Fang Liu
- College of Materials Science and Engineering, South China University of Technology, Guangzhou, Guangdong, 510641, People's Republic of China.
| | - Jingwei He
- College of Materials Science and Engineering, South China University of Technology, Guangzhou, Guangdong, 510641, People's Republic of China.
| | - Sui Mai
- Hospital of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China.
- Guanghua School of Stomatology, Sun Yat-sen University, Guangdong, 510055, People's Republic of China
- Institute of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510055, People's Republic of China
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Ghani SMA, Hassan MIA, Abdullah AH, Ghani ARA, Izra'ai SI, Aregawi W, Chew HP, Fok A. Linear and volumetric shrinkage displacements of resin composite restorations with and without debonding. Dent Mater J 2023; 42:659-668. [PMID: 37612060 DOI: 10.4012/dmj.2023-023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
The study aimed to compare shrinkage displacements of fully and partially bonded resin composite restorations (RCRs). Two groups (n=5) Class-I RCR evaluated: Group 1 (G1) fully bonded and Group 2 (G2) debonded at the floor. Experimental results were compared with predictions from simple theory and finite element analysis (FEA). The experimental linear surface displacement (LSD) was G1 62.5±5.2 µm and G2 32.8±4.0 µm. Theoretically-predicted LSD for G1 60.1±7.4 µm and G2 31.3±7.5 µm. FEA-predicted LSD were G1 65.2 µm and G2 34.6 µm. The experimental volumetric surface displacement (VSD) was G1 1.22±0.2 mm3 and G2 0.63±0.2 mm3. Theoretically-predicted VSD for G1 1.36±0.2 mm3 and G2 0.67±0.2 mm3. No significant difference (p>0.05) was found in LSD and VSD among the experimental, theoretical and FEA in the same group. Significant differences (p<0.05) were noted between the two groups, with LSD and VSD of G2 values being almost half of G1. This pattern gave an insight of a debond restoration characteristics.
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Affiliation(s)
- Siti Mariam Ab Ghani
- Center for Restorative Dentistry Studies, Faculty of Dentistry, Universiti Teknologi MARA
| | | | | | | | | | - Wondwosen Aregawi
- Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota
| | - Hooi Pin Chew
- Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota
| | - Alex Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota
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Ni J, Xu L, Lin Y, Lai D, Huang X. Effects on different full-coverage designs and materials of crack propagation in first mandibular molar: an extended finite element method study. Front Bioeng Biotechnol 2023; 11:1222060. [PMID: 37650043 PMCID: PMC10464904 DOI: 10.3389/fbioe.2023.1222060] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/07/2023] [Indexed: 09/01/2023] Open
Abstract
Objectives: This study aims to investigate the biomechanical properties of fracture resistance in cracked teeth using five different full-coverage restorations made of three different materials. Materials and Methods: A 3D model of a mandibular first molar was created to design five different full-coverage repair models: crown, crown with composite resin filling inside, occlusal veneer, occlusal veneer with composite resin filling inside and onlay. These repair models were fabricated using three different materials, namely, zirconia, lithium disilicate (LDS), and a hybrid polymer-infiltrated ceramic network material (PIC). In total, 15 repair models were tested using the extended finite element method (XFEM), with an occlusal load of 5000 N applied slowly to the occlusal surface of the restoration. The analysis of stress distribution in the restoration and dentin crack line was conducted to measure and record the crack initial load on the restoration and dentin. Results: The results showed that restorations on the occlusal surface significantly improved crack resistance, with zirconia exhibiting superior fracture resistance among the materials tested. Restorations of crown with composite resin filling inside demonstrated the highest resistance to fracture, while occlusal veneers showed the lowest. MPS concentration was observed at the interface between the restoration and dentin and at the root bifurcation, with the highest values at the top of crack development. Dentin covered by oxidized restorations had the highest displacement, while PIC restorations exhibited the lowest. Pulp analysis revealed selective MPS concentration and strain patterns in models with zirconia restorations and onlay, with pronounced pulp displacement in zirconia restorations and onlay. Enamel analysis indicated larger MPS values and displacements in zirconia restoration models and onlay, with higher strain in onlay. Restoration played a crucial role in protecting the tooth, with crack propagation initial loads in dentin surpassing restorations in experimental groups. Conclusion: This study confirms that full-coverage restorations significantly increased the fracture resistance of cracked teeth, with zirconia restorations significantly protecting the underlying cracked tooth. Elimination of fracture lines in the restoration design can improve fracture resistance in cracked teeth. The findings have implications for dental prosthetic design and clinical practice.
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Affiliation(s)
| | | | | | | | - Xiaohong Huang
- Department of Stomatology, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
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Al Aggan N, Nabih SM, Abd Al Hady AAA. Influence of the cervical margin relocation on stress distribution -. BRAZILIAN JOURNAL OF ORAL SCIENCES 2023; 22:e230356. [DOI: 10.20396/bjos.v22i00.8670356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023] Open
Abstract
Aim: Evaluate the influence of the cervical margin relocation (CMR) on stress distribution in the lower first molar restored with direct nano-ceramic composite (zenit). Methods: A 3D model of the lower first molar was modeled and used. Standardized mesio-occluso-distal (MOD) preparation consisted in two models used in this study with mesial subgingival margin in model II. (CMR) was applied in model II using flowable composite or resin glass ionomer (Riva). Both models were restored with nanoceramic composite and then subjected to six runs (2 for the model I and 4 for model II) with load (100N) as two load cases, one at (11º) and other at (45º) from the vertical axis. The stress distributions (FEA) in the final restoration and (CMR) material were analyzed using 3D models. Results: The two models recorded an equivalent Von Mises stress and Total deformation in the final restoration, regardless of the difference in the oblique angle incidence from (11º to 45º) or the type of the material used for (CMR) there was no significant difference in the (FEA) between the model with CMR (model II) and the model without CMR (model I). Conclusions: (CMR) technique seems to be biomechanically beneficial with high eccentric applied stress, (CMR) with resin glass ionomer or flowable composite resin in combination with nanoceramic composite improved the biomechanical behavior of (MOD) cavities extended below cement enamel junction (CMR) with high modulus elasticity material like (Riva) exhibits a more uniform stress distribution.
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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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A Comparative Study of the Solubility and Sorption Properties of Resin Modified Glass Ionomer and a Bioactive Liner. JOURNAL OF RESEARCH IN DENTAL AND MAXILLOFACIAL SCIENCES 2022. [DOI: 10.52547/jrdms.7.3.125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Lin F, Ordinola-Zapata R, Fok ASL, Lee R. Influence of minimally invasive endodontic access cavities and bonding status of resin composites on the mechanical property of endodontically-treated teeth: A finite element study. Dent Mater 2021; 38:242-250. [PMID: 34930622 DOI: 10.1016/j.dental.2021.12.007] [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: 09/01/2021] [Revised: 11/27/2021] [Accepted: 12/08/2021] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To study the mechanical behavior of endodontically-treated teeth with minimally invasive endodontic access cavities and resin composite restorations under different bonding conditions using finite element analysis (FEA). METHODS Four Class-II endodontic access cavities including the mesio-occlusal minimally-invasive (MO-MIE), mesio-occlusal conventional (MO-CONV), disto-occlusal minimally-invasive (DO-MIE), and disto-occlusal conventional (DO-CONV) cavities were prepared in 3D-printed maxillary first molars. Each tooth was subjected to root canal preparation and scanned using micro-CT to provide a 3D structural model which was virtually restored with resin composite. An intact 3D-printed molar was used as control. FEA was conducted under a 250-N vertical load. Three different interfacial bonding conditions between dentin/enamel and resin composite were considered, i.e. fully bonded, partially debonded, and fully debonded. The maximum principal stress of dentin and the normal tensile stress at the interfaces were recorded. The risk factor of failure for each component was then calculated. RESULTS In the fully-bonded tooth, the dentin-composite interface showed significantly higher stress and a higher risk factor than dentin, indicating that debonding at the dentin-composite interface would occur prior to dentin fracture. With the dentin-composite interface debonded, the enamel-composite interface exhibited higher stress and a higher risk factor than dentin, indicating that debonding at the enamel-composite interface would occur next, also prior to dentin fracture. With the resin composite fully debonded from the tooth, stress in dentin increased significantly. Irrespective of the bonding status, the CONV groups exhibited higher median stresses in dentin than the MIE groups. SIGNIFICANCE Within the limitation of this study, it was shown that debonding of the resin composite restoration increased the stress in dentin and hence the risk of dentin fracture in endodontically-restored teeth. Minimally-invasive access cavities could better safeguard the fracture resistance of interproximally-restored teeth compared to conventional ones.
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Affiliation(s)
- Fei Lin
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
| | - Ronald Ordinola-Zapata
- Division of Endodontics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alex S L Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Roy Lee
- Division of Endodontics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
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Rehabilitation of severely-destructed endodontically treated premolar teeth with novel endocrown system: Biomechanical behavior assessment through 3D finite element and in vitro analyses. J Mech Behav Biomed Mater 2021; 126:105031. [PMID: 34922296 DOI: 10.1016/j.jmbbm.2021.105031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/30/2021] [Accepted: 12/06/2021] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Rehabilitation of endodontically treated premolars with extensive coronal destruction through endocrown approach remains a controversial topic in reconstructive dentistry. There is no clear consensus in the literature which endocrown design with which material is the most effective restoration option for severely-destructed endodontically treated premolars. The aim of this study was to assess the biomechanical behavior of endodontically treated maxillary first premolars restored with a novel endocrown system compared to the conventional one varying the applied load type through finite element and in vitro analyses. MATERIALS AND METHODS For finite element analysis, two models representing two endocrown systems used for restoration of severely-destructed endodontically treated maxillary first premolar tooth were generated: Model C for the conventional monolithic IPS e.max CAD endocrown and Model P for the novel bi-layered endocrown (PEKKTON ivory coping veneered with cemented IPS e.max CAD). Modified von Mises stress values on the remaining tooth structure, cement lines and restorative materials were evaluated separately under axial and oblique loading of 450 N. For in vitro analysis, forty sound human bifurcated maxillary first premolars were collected, endodontically-treated, and divided into 2 main groups (n = 20) according to the system used for endocrown fabrication; Group C: the conventional monolithic endocrowns and Group P: the novel bi-layered endocrowns. All specimens were subjected to an artificial thermomechanical aging protocol. Each main group was subdivided into two subgroups (n = 10) according to the loading type (axial and oblique) applied during the fracture resistance test. Qualitative analysis using Stereomicroscopy and Scanning Electron Microscopy was performed. Data were statistically analyzed at p-value ≤ 0.05. RESULTS Regarding stress distribution pattern of remaining tooth structure (enamel and dentin), both endocrown systems and cement lines under both axial and oblique load application, Model P resulted in lower stresses than Model C. The oblique stress values of all analyzed structures were higher than corresponding values resulted axially. Considering failure load, a significantly higher load was recorded for Group P when axial or oblique loading was applied (p = 0.00). A significantly higher failure load was recorded with axial loading for both main groups. With regard to failure mode, a statistically significant difference was observed between main groups (p = 0.033), with more favorable failures detected for Group P axially. CONCLUSIONS Compared to the conventional endocrown system, the studied novel system improved the biomechanical behavior within tooth/restoration complex of the restored severely-destructed endodontically treated maxillary first premolar teeth, whatever the applied load type. CLINICAL SIGNIFICANCE The novel endocrown system using a PEKK coping veneered with cemented IPS e.max CAD can be considered a favorable promising option for restoration of severely-destructed endodontically treated premolar teeth, with more protection for residual tooth structure. It can be considered as a conservative alternative option to the conventional treatment modalities not only for normal clinical conditions, but also for parafunctional cases.
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Lee EH, Ahn JS, Lim YJ, Kwon HB, Kim MJ. Effect of post-curing time on the color stability and related properties of a tooth-colored 3D-printed resin material. J Mech Behav Biomed Mater 2021; 126:104993. [PMID: 34871954 DOI: 10.1016/j.jmbbm.2021.104993] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/19/2021] [Accepted: 11/21/2021] [Indexed: 01/27/2023]
Abstract
This study investigated the effect of post-curing time on the color stability and related properties, such as degree of conversion (DC), surface roughness, water contact angle, water sorption (Wsp), and water solubility (Wsl) of 3D-printed resin for dental restorations. The 3D-printed specimens were divided into four groups according to the post-curing time (0, 5, 10, and 20 min). Color changes (ΔE00) of the specimens immersed in aging media were measured using a spectrophotometer at different aging times. The DC of the resin was measured using a FTIR. The surface roughness (Ra) of the resin immersed in coffee was measured at different aging times. Water contact angle was evaluated using the sessile drop method, and Wsp and Wsl were tested according to the ISO 4049:2019. The ΔE00 values of the specimens immersed in coffee and red wine decreased with increasing post-curing time. As the post-curing time increased up to 10 min, the DC increased and water contact angle decreased. The Ra value of the group without post-curing (0 min) increased gradually for 30 days, except between 7 and 15 days. However, when the post-curing time increased to greater than 10 min, no apparent change in Ra value was detected. The Wsp and Wsl of the group without post-curing were significantly lower and larger than that of the other groups, respectively. The longer the post-curing time of the tooth-colored 3D-printed resin, the better the color stability. The post-curing time of the 3D-printed resin affected the DC, surface roughness after aging in the staining media, water contact angle, water sorption, and water solubility.
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Affiliation(s)
- Eun-Hyuk Lee
- Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Jin-Soo Ahn
- Dental Research Institute and Department of Dental Biomaterials Science, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Young-Jun Lim
- Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Ho-Beom Kwon
- Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Myung-Joo Kim
- Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea.
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Meng Q, Zhang Y, Chi D, Gong Q, Tong Z. Resistance fracture of minimally prepared endocrowns made by three types of restorative materials: a 3D finite element analysis. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2021; 32:137. [PMID: 34716807 PMCID: PMC8557147 DOI: 10.1007/s10856-021-06610-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
A thin endocrown restoration was often applied in endodontically treated teeth with vertical bite height loss or inadequate clinical crown length. A model of mandibular molars made by endocrown restoration with 1 mm thickness and 2 mm depth of pulp chamber was constructed and imported into FEA ANSYS v18.0 software. The three CAD/CAM materials, feldspathic (Mark2), lithium disilicate (EMAX), and lava ultimate (LU), were assigned, and the five load indenters were loaded on the full occlusal (FO), occlusal center (OC), central fossa (CF), buccal groove (BG), and mesiobuccal cusp (MC) of restoration in the model. The MinPS and MaxPS of the thin endocrown were significantly higher than those of tooth tissue in five types of loads except for the LU endocrown loaded in the FO group. The smaller the contact surface of the load was, the higher MaxPS and MinPS were. MaxPS and MinPS of the MC were the highest, followed by the BG and CF in the restoration. In the stress distribution of tooth tissue, MaxPS in the LU endocrown accumulated at the external edge of enamel and was significantly higher than MaxPS in Mark2 and EMAX endocrown concentrated on the chamber wall of dentin under OC, CF and BG loads. Within the limitations of this FEA study, the LU endocrown transferred more stress to tooth tissue than Mark2 and EMAX, and the maximum principal stress on endocrown restoration and tooth tissue at the mesiobuccal cusp load was higher than that at the central fossa and buccal groove load.
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Affiliation(s)
- Qingzhen Meng
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yuejiao Zhang
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Danlu Chi
- The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Qimei Gong
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhongchun Tong
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
- Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
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The effect of dental restoration geometry and material properties on biomechanical behaviour of a treated molar tooth: A 3D finite element analysis. J Mech Behav Biomed Mater 2021; 125:104892. [PMID: 34688146 DOI: 10.1016/j.jmbbm.2021.104892] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/08/2021] [Accepted: 10/10/2021] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To test the hypothesis that restoration of class II mesio-occlusal-distal (MOD) cavities can be strengthened through judicious choice of restoration geometry and material properties. METHODS An intact extracted human maxillary molar tooth was digitized, segmented, reconstructed, and four 3D restored tooth models were developed with four different restoration geometries: one straight, one single-curved, and two double-curved. Stress analysis was conducted for representative loading using finite element analysis, and maximum principal stresses were determined at the dentine-enamel and restoration-enamel junctions. A range of restorative material elastic moduli (5-80 GPa) and Poisson's ratios (0.25-0.35) were studied. Vertical loads of 400 N were applied on occlusal points, while the roots of the molar teeth, below the crevices, were supported in all directions. All the materials were modelled as homogeneous, isotropic, and elastic. RESULTS The maximum principal stresses at the restoration-enamel junctions were strongly dependent on the MOD restoration geometries. Peak stresses occurred along the palatal surface of the restoration rather than the opposite buccal surface. Double-curved restorations showed the lowest peak stress at restoration-enamel junctions. Choice of the mechanical properties of restorative material in the range of 5-35 GPa further reduced stress concentrations on the enamel. SIGNIFICANCE Class II MOD restorations may be stronger if designed with double-curved marginal geometries that can reduce stress concentrations. Designs with convex and concave geometries were particularly effective because they reduced stress concentrations dramatically. Results suggest that relatively minor changes to the geometry of a restoration can have a substantial effect on stress at the restoration-enamel junction and motivate future experimental analysis.
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Montoya C, Jain A, Londoño JJ, Correa S, Lelkes PI, Melo MA, Orrego S. Multifunctional Dental Composite with Piezoelectric Nanofillers for Combined Antibacterial and Mineralization Effects. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43868-43879. [PMID: 34494813 DOI: 10.1021/acsami.1c06331] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
After nearly seven decades of development, dental composite restorations continue to show limited clinical service. The triggering point for restoration failure is the degradation of the bond at the tooth-biomaterial interface from chemical, biological, and mechanical sources. Oral biofilms form at the bonded interfaces, producing enzymes and acids that demineralize hard tissues and damage the composite. Removing bacteria from bonded interfaces and remineralizing marginal gaps will increase restorations' clinical service. To address this need, we propose for the first time the use of piezoelectric nanoparticles of barium titanate (BaTiO3) as a multifunctional bioactive filler in dental resin composites, offering combined antibacterial and (re)mineralization effects. In this work, we developed and characterized the properties of dental piezoelectric resin composites, including the degree of conversion and mechanical and physical properties, for restorative applications. Moreover, we evaluated the antibacterial and mineralization responses of piezoelectric composites in vitro. We observed a significant reduction in biofilm growth (up to 90%) and the formation of thick and dense layers of calcium phosphate minerals in piezoelectric composites compared to control groups. The antibacterial mechanism was also revealed. Additionally, we developed a unique approach evaluating the bond strength of dentin-adhesive-composite interfaces subjected to simultaneous attacks from bacteria and cyclic mechanical loading operating in synergy. Our innovative bioactive multifunctional composite provides an ideal technology for restorative applications using a single filler with combined long-lasting nonrechargeable antibacterial/remineralization effects.
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Affiliation(s)
- Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Anubhav Jain
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Juan José Londoño
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Research Group (GIB), Department of Mechanical Engineering, Universidad EAFIT, Medellin 050022, Colombia
| | - Santiago Correa
- Bioengineering Research Group (GIB), Department of Mechanical Engineering, Universidad EAFIT, Medellin 050022, Colombia
| | - Peter I Lelkes
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Mary Anne Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, Maryland 21201, United States
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, United States
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Reddy JK, Malini DL, Ballullaya SV, Pushpa S, Devalla S, Reddy AV. Influence of "MOTRCS" factors on the performance of various direct and indirect restorations: A finite element analysis. J Conserv Dent 2021; 24:15-23. [PMID: 34475674 PMCID: PMC8378485 DOI: 10.4103/jcd.jcd_471_20] [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: 09/14/2020] [Revised: 11/25/2020] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Aim of the Study: The purpose of the study is to evaluate the occlusal relationship of the mesiobuccal cusp of a mandibular first molar with the marginal ridge of maxillary first molar and second premolar and to analyze the effect of the above occlusal relation on different direct and indirect restorations using finite element analysis (FEA). Methodology: Four hundred volunteers studying in a dental college were screened, of which 100 volunteers were selected for studying occlusal relationships based on the inclusion and exclusion criteria. The two most common occlusal relationships were considered for analyzing two direct (amalgam and direct composite restorations) and two indirect restorations (composite and ceramic restorations). Three-dimensional (3D) scanning of the models was performed, and Class II tooth preparations specific for each restorative material were prepared digitally on 3D models. FEA was employed to study von Mises (VM) stress, principal stresses, and cuspal deflection for each restorative material, and failure of the tooth-restoration unit was calculated using the modified Mohr failure criterion. Results: Among all the analyzed materials, cuspal deformation, principal stresses, and VM stresses were high for direct composite restoration and least for ceramic inlay. According to modified Mohr criteria, except for direct composite, all other materials performed better. Conclusion: Silver amalgam and ceramic restorations presented with minimal stress concentration and cuspal deflection, and Type I occlusal relationship presented with higher stress concentration compared to Type II.
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Affiliation(s)
- Jonnala Kruthika Reddy
- Department of Conservative Dentistry and Endodontics, St. Joseph Dental College, Eluru, Andhra Pradesh, India
| | - Duvvuri Lakshmi Malini
- Department of Conservative Dentistry and Endodontics, Government Dental College, Vijayawada, Andhra Pradesh, India
| | - Srinidhi Vishnu Ballullaya
- Department of Conservative Dentistry and Endodontics, St. Joseph Dental College, Eluru, Andhra Pradesh, India
| | - S Pushpa
- Department of Conservative Dentistry and Endodontics, St. Joseph Dental College, Eluru, Andhra Pradesh, India
| | - Srihari Devalla
- Department of Conservative Dentistry and Endodontics, St. Joseph Dental College, Eluru, Andhra Pradesh, India
| | - A Venkat Reddy
- Department of Prosthodontics and Crown and Bridge, St. Joseph Dental College, Eluru, Andhra Pradesh, India
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Tribst JPM, Dal Piva AMDO, Ausiello P, De Benedictis A, Bottino MA, Borges ALS. Biomechanical Analysis of a Custom-Made Mouthguard Reinforced With Different Elastic Modulus Laminates During a Simulated Maxillofacial Trauma. Craniomaxillofac Trauma Reconstr 2021; 14:254-260. [PMID: 34471482 DOI: 10.1177/1943387520980237] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background/Aims There is a lack of data regarding the influence of different laminates for mouthguard reinforcement in the mechanical response during an impact in the orofacial region. The aim of this study was to verify the influence of the laminate framework on the stresses and strains of the anterior teeth and displacement of ethylene-vinyl acetate (EVA) custom-made mouthguards during a simulated impact. The null hypotheses was that the different laminates reinforcement would present the similar effect in maxillary structures, regardless the elastic modulus. Methods A finite element model of human maxillary central incisors with an antagonist contact was used. A linear quasi-static analysis was used to simulate the force exerted during an impact. A total of 5 different layers were simulated inside the mouthguard at the labial portion according to the Elastic Modulus 1 MPa (Extremely flexible), 9 GPa (Low modulus reinforcement), 18 GPa (Without reinforcement), 50 GPa (Flexible alloy), 100 GPa (Titanium alloy) and 200 GPa (Hard material). The results were evaluated by means of Maximum Principal Stress (in the tooth and bone), Microstrain (periodontal ligament) and Displacement (mouthguard) criteria. Results The elastic modulus of the material inside the MG influenced the stress distribution on the enamel buccal face. However, it did not affect the bone tissue stress, periodontal ligament strain or root dentin tissue stress. Conclusion: The use of reinforcement inside the custom-made mouthguard can modify the stress generated in the enamel buccal surface without improvement to the root dentin, periodontal ligament or bone tissue.
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Affiliation(s)
- João Paulo Mendes Tribst
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, SP, Brazil
| | - Amanda Maria de Oliveira Dal Piva
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, SP, Brazil
| | - Pietro Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - Arianna De Benedictis
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - Marco Antonio Bottino
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, SP, Brazil
| | - Alexandre Luiz Souto Borges
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, SP, Brazil
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Liu R, Wang E, Guo Y, Zhou Q, Zheng Y, Zhai J, Zhang K, Zhang B. Enhanced antibacterial properties and promoted cell proliferation in glass ionomer cement by modified with fluorinated graphene-doped. J Appl Biomater Funct Mater 2021; 19:22808000211037487. [PMID: 34428976 DOI: 10.1177/22808000211037487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In this study, we aimed to improve the properties of conventional glass ionomer cement (GIC), including mechanical properties, wear resistance, antibacterial properties and biological activity, by adding fluorinated graphene (FG). Composites of synthesised FG and GIC were examined after being combined at different mass proportions (0, 0.5, 1.0 and 2.0 wt%). The microstructure and morphology of FG prepared via the hydrothermal method was characterised using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The FG/GIC composite was obtained through the blending method and characterised using SEM. Then, the Vickers microhardness and the wear property of the FG/GIC composite-imitated brushing was measured. The plate count and dilution methods (10-fold) were adopted to investigate the antibacterial properties of FG/GIC by incubating Escherichia coli and Staphylococcus aureus. The biocompatibility of FG/GIC containing the adhesion and cytotoxicity of mouse fibroblast cells (L929) was estimated by the MTT and acridine orange (AO) fluorescent staining. Our results demonstrated that the hardness and abrasive wear resistance of the composites increased, and the microhardness parameter changes exhibited a gradual increase as the concentration continued to increase. A 2.0 wt% FG concentration could effectively improve the bacterial inhibition performance of GIC and was directly proportional to the concentration of FG. The composite materials showed no apparent cytotoxicity on normal L929 cells compared to the control group, and the materials exhibited no cytotoxic effect compared to traditional GIC. Thus, FG/GIC has potential therapeutic value in the field of dental treatment.
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Affiliation(s)
- Ruimin Liu
- Department of Oral and Maxillofacial Surgery, Gansu Provincial Hospital, Lanzhou, PR China
| | - Errui Wang
- Department of Stomatology, Lanzhou University, Lanzhou, PR China
| | - Yumeng Guo
- Department of Stomatology, Lanzhou University, Lanzhou, PR China
| | - Qiaozhen Zhou
- Department of Stomatology, Lanzhou University, Lanzhou, PR China
| | - Yayuan Zheng
- Department of Stomatology, Lanzhou University, Lanzhou, PR China
| | - Junkai Zhai
- Department of Stomatology, Lanzhou University, Lanzhou, PR China
| | - Kailiang Zhang
- Department of Stomatology, Lanzhou University, Lanzhou, PR China
| | - Baoping Zhang
- Department of Stomatology, Lanzhou University, Lanzhou, PR China.,Institute of Biomechanics and Medical Engineering, Lanzhou University, Lanzhou, PR China
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Influence of post type on periapical status: a prospective study in a Brazilian population. Clin Oral Investig 2021; 26:781-787. [PMID: 34231058 DOI: 10.1007/s00784-021-04057-6] [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: 12/07/2020] [Accepted: 06/26/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES This prospective study assessed the effect of post type used to restore endodontically treated teeth in the onset, progression, and remission of periapical lesions. MATERIALS AND METHODS One hundred and forty teeth (92 patients) were endodontically treated and received a glass fiber post or a cast metal post and a final restoration at a University Clinic by undergraduate students. All patients were followed up for a mean period of 5.1 ± 2.2 years. Periapical Index (PAI) was used for endodontic assessment. Two calibrated and blind examiners assessed the radiographs. The longevity of the endodontic treatment was analyzed using Kaplan-Meier statistics. RESULTS Of the included teeth, 67.1% received glass fiber posts while 32.9% received cast metal posts. There were 4 endodontic failures, two glass fiber posts with a PAI = 3 in the baseline and PAI = 4 in the last follow-up, and one PAI = 4 in baseline and last follow-up. One cast metal post-failure was PAI = 4 in the baseline and the last follow-up. After 9.4 years, the overall success rate of the endodontic treatment was 97.1% (p = 0.7). CONCLUSIONS The tested posts presented similar endodontic healing. Precautions taken during endodontic therapy, post cementation, and final restoration are more likely to be responsible for the success of endodontic treatment rather than a specific type of post. Clinical relevance The type of post is not related to the success of the endodontic treatment.
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21
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Effect of Direct and Indirect Materials on Stress Distribution in Class II MOD Restorations: A 3D-Finite Element Analysis Study. BIOMED RESEARCH INTERNATIONAL 2021; 2020:7435054. [PMID: 33381580 PMCID: PMC7755472 DOI: 10.1155/2020/7435054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 12/02/2020] [Accepted: 12/05/2020] [Indexed: 11/18/2022]
Abstract
The aim of this study is to investigate the stress distributions of different restoration options for class II mesio-occluso-distal (MOD) cavities. A class II MOD cavity with proximal box gingival floor 1 mm below cementoenamel junction was designed in a mandibular first molar tooth model. 3D finite-element analysis (FEA) and 3D-CAD modelling were used to examine the occlusal stresses distributed to the remaining buccal enamel (RBE), remaining lingual enamel (RLE), adhesive surfaces, and restorative materials by direct and indirect materials resulting from a 600 N of static occlusal load stimulating foodstuff. von Mises (VM) and maximum principal (Pmax) stresses were evaluated for two CAD/CAM materials and three direct materials. CAD/CAM materials exerted less stress than the direct restorative materials. Significant von Mises and Pmax stress value differences were seen among all restoration models on RBE. Reducing RLE and including it into the cavity would be a more effective option for this model in this scenario. As VM and Pmax stresses of PIHC CAD/CAM material for RBE and dentin were significantly lower than other tested materials, it may be the choice of material for indirect MOD restorations.
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Benevides F, Cimões R, Vajgel A, Wilmersdorf RB, Vajgel BDCF. Stress evaluation of different implant lengths on atrophic edentulous mandibles with fixed full-arch implant-supported prosthesis: a finite element analysis. Comput Methods Biomech Biomed Engin 2021; 24:358-374. [PMID: 34121526 DOI: 10.1080/10255842.2020.1817406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Finite element analysis was used to compare the effect of different implant lengths on atrophic mandible with full-arch fixed prostheses. Four models were constructed with different implant lengths: 4, 6, 8 and 10 mm. A 100-N occlusal load was applied. The stress at the bone level, implant, and prosthetic components were obtained. Similar behavior was observed for all groups, except for 4 mm, which showed more discrepant values for all prosthetic components. Although longer implants presented better biomechanical behavior, the 4 mm implant seems to be a viable alternative for severely atrophic mandibles, however, further studies need to be carried out.
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Affiliation(s)
| | - Renata Cimões
- Department of Prosthesis and Oral Facial Surgery, Federal University of Pernambuco, Recife, Brazil
| | - André Vajgel
- University of Pernambuco, School of Dentistry, Arcoverde, PE, Brazil
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Aker Sagen M, Dahl JE, Matinlinna JP, Tibballs JE, Rønold HJ. The influence of the resin-based cement layer on ceramic-dentin bond strength. Eur J Oral Sci 2021; 129:e12791. [PMID: 34057757 DOI: 10.1111/eos.12791] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/29/2021] [Accepted: 03/29/2021] [Indexed: 11/29/2022]
Abstract
The purpose of the study was to measure the cement thickness obtained when ceramic rods were luted to dentin and to analyze the relation between cement thickness and the previously published tensile bond strength of similar test specimens. In addition, the ISO standard 4049:2019 method was used to determine the film thickness of the used cements. Zirconia (n = 100) and lithium disilicate (n = 50) rods were cemented to bovine dentin using one of five different resin-based cements. The ceramic-dentin test specimens were cut into two slices and the cement thickness was measured using a scanning electron microscope and compared to the bond strength values of similar specimens already published. The mean cement thickness recorded for ceramic rods cemented to dentin was in the range 20-40 μm, which was larger than the cement film thickness found by the ISO method. The cement film thickness determined according to ISO standard methods did not concur with the results obtained when cementing ceramic rods to dentin. For cementing ceramic restorations, a cement thickness in the range 25-35 μm seems to be favorable for the bond strength.
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Affiliation(s)
- Mina Aker Sagen
- Institute of Clinical Dentistry, University of Oslo, Oslo, Norway
| | - Jon Einar Dahl
- Institute of Clinical Dentistry, University of Oslo, Oslo, Norway.,Nordic Institute of Dental Materials (NIOM), Oslo, Norway
| | - Jukka Pekka Matinlinna
- Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, PR China
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Chen YC, Lin CL, Hou CH. Investigating inlay designs of class II cavity with deep margin elevation using finite element method. BMC Oral Health 2021; 21:264. [PMID: 33993877 PMCID: PMC8127254 DOI: 10.1186/s12903-021-01630-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/06/2021] [Indexed: 11/25/2022] Open
Abstract
Background This study evaluates the mechanical performance of deep margin elevation technique for carious cavities by considering the shape designs and material selections of inlay using a computational approach combined with the design of experiments method. The goal is to understand the effects of the design parameters on the deep margin elevation technique and provide design guidelines from the biomechanics perspective. Methods Seven geometric design parameters for defining an inlay’s shape of a premolar were specified, and the influence of cavity shape and material selection on the overall stress distribution was investigated via automated modelling. Material selection included composite resin, ceramic, and lithium disilicate. Finite element analysis was performed to evaluate the mechanical behavior of the tooth and inlay under a compressive load. Next, the analysis of variance was conducted to identify the parameters with a significant effect on the stress occurred in the materials. Finally, the response surface method was used to analyze the stress responses of the restored tooth with different design parameters. Results The restored tooth with a larger isthmus width demonstrated superior mechanical performance in all three types of inlay materials, while the influence of other design parameters varied with the inlay material selection. The height of the deep margin elevation layer insignificantly affected the mechanical performance of the restored tooth. Conclusions A proper geometric design of inlay enhances the mechanical performance of the restored tooth and could require less volume of the natural dentin to be excavated. Furthermore, under the loading conditions evaluated in this study, the deep margin elevation layer did not extensively affect the strength of the tooth structure. Supplementary Information The online version contains supplementary material available at 10.1186/s12903-021-01630-z.
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Affiliation(s)
- Yung-Chung Chen
- School of Dentistry and Institute of Oral Medicine, Medical College, National Cheng Kung University, Tainan, Taiwan, Republic of China.,Division of Prosthodontics, Department of Stomatology, National Cheng Kung University Hospital, National Cheng Kung University, Tainan, Taiwan, Republic of China
| | - Chi-Lun Lin
- Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
| | - Chun-Hsien Hou
- Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China
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Finite Element Modelling and Experimental Validation of the Enamel Demineralisation Process at the Rod Level. J Adv Res 2021; 29:167-177. [PMID: 33842014 PMCID: PMC8020348 DOI: 10.1016/j.jare.2020.08.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/27/2020] [Accepted: 08/29/2020] [Indexed: 11/26/2022] Open
Abstract
In the past years, a significant amount of effort has been directed at the observation and characterisation of caries using experimental techniques. Nevertheless, relatively little progress has been made in numerical modelling of the underlying demineralisation process. The present study is the first attempt to provide a simplified calculation framework for the numerical simulation of the demineralisation process at the length scale of enamel rods and its validation by comparing the data with statistical analysis of experimental results. FEM model was employed to simulate a time-dependent reaction-diffusion equation process in which H ions diffuse and cause demineralisation of the enamel. The local orientation of the hydroxyapatite crystals was taken into account. Experimental analysis of the demineralising front was performed using advanced high-resolution synchrotron X-ray micro-Computed Tomography. Further experimental investigations were conducted by means of SEM and STEM imaging techniques. Besides establishing and validating the new modelling framework, insights into the role of the etchant solution pH level were obtained. Additionally, some light was shed on the origin of different types of etching patterns by simulating the demineralisation process at different etching angles of attack. The implications of this study pave the way for simulations of enamel demineralisation within different complex scenarios and across the range of length scales. Indeed, the framework proposed can incorporate the presence of chemical species other than H ions and their diffusion and reaction leading to dissolution and re-precipitation of hydroxyapatite. It is the authors’ hope and aspiration that ultimately this work will help identify new ways of controlling and preventing caries.
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Gomes de Carvalho AB, de Andrade GS, Mendes Tribst JP, Grassi EDA, Ausiello P, Saavedra GDSFA, Bressane A, Marques de Melo R, Borges ALS. Mechanical Behavior of Different Restorative Materials and Onlay Preparation Designs in Endodontically Treated Molars. MATERIALS 2021; 14:ma14081923. [PMID: 33921347 PMCID: PMC8070423 DOI: 10.3390/ma14081923] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 11/24/2022]
Abstract
This study evaluated the effect of the combination of three different onlay preparation designs and two restorative materials on the stress distribution, using 3D-finite element analysis. Six models of first lower molars were created according to three preparation designs: non-retentive (nRET), traditional with occlusal isthmus reduction (IST), and traditional without occlusal isthmus reduction (wIST); and according to two restorative materials: lithium-disilicate (LD) and nanoceramic resin (NR). A 600 N axial load was applied at the central fossa. All solids were considered isotropic, homogeneous, and linearly elastic. A static linear analysis was performed, and the Maximum Principal Stress (MPS) criteria were used to evaluate the results and compare the stress in MPa on the restoration, cement layer, and tooth structure (enamel and dentin). A novel statistical approach was used for quantitative analysis of the finite element analysis results. On restoration and cement layer, nRET showed a more homogeneous stress distribution, while the highest stress peaks were calculated for LD onlays (restoration: 69–110; cement layer: 10.2–13.3). On the tooth structure, the material had more influence, with better results for LD (27–38). It can be concluded that nRET design showed the best mechanical behavior compared to IST and wIST, with LD being more advantageous for tooth structure and NR for the restoration and cement layer.
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Affiliation(s)
- Ana Beatriz Gomes de Carvalho
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos 12245-000, Brazil; (A.B.G.d.C.); (G.S.d.A.); (E.D.A.G.); (G.d.S.F.A.S.); (R.M.d.M.); (A.L.S.B.)
| | - Guilherme Schmitt de Andrade
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos 12245-000, Brazil; (A.B.G.d.C.); (G.S.d.A.); (E.D.A.G.); (G.d.S.F.A.S.); (R.M.d.M.); (A.L.S.B.)
| | - João Paulo Mendes Tribst
- Graduate Program in Dentistry, Department Dentistry, University of Taubate (UNITAU), Taubate 12020-270, Brazil;
| | - Elisa Donária Aboucauch Grassi
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos 12245-000, Brazil; (A.B.G.d.C.); (G.S.d.A.); (E.D.A.G.); (G.d.S.F.A.S.); (R.M.d.M.); (A.L.S.B.)
| | - Pietro Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, School of Dentistry, University of Naples Federico II, 80138 Naples, Italy
- Correspondence:
| | - Guilherme de Siqueira Ferreira Anzaloni Saavedra
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos 12245-000, Brazil; (A.B.G.d.C.); (G.S.d.A.); (E.D.A.G.); (G.d.S.F.A.S.); (R.M.d.M.); (A.L.S.B.)
| | - Adriano Bressane
- Graduate Oral Health Applied Science, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos 12245-000, Brazil;
| | - Renata Marques de Melo
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos 12245-000, Brazil; (A.B.G.d.C.); (G.S.d.A.); (E.D.A.G.); (G.d.S.F.A.S.); (R.M.d.M.); (A.L.S.B.)
| | - Alexandre Luiz Souto Borges
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos 12245-000, Brazil; (A.B.G.d.C.); (G.S.d.A.); (E.D.A.G.); (G.d.S.F.A.S.); (R.M.d.M.); (A.L.S.B.)
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Sun T, Shao B, Liu Z. Effects of the lining material, thickness and coverage on residual stress of class II molar restorations by multilayer technique. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 202:105995. [PMID: 33592326 DOI: 10.1016/j.cmpb.2021.105995] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
OBJECTIVE This study aims to analyse the influence of different lining material, thickness and coverage on residual stress of class II molar restoration by the multilayer technique through the three-dimensional (3D) finite element (FE) method. The objective is to reveal the correlations between the base layer configurations and the residual stress distributions of the tooth. METHODS A 3D reconstructed model of an extracted first molar was built through micro-CT images and a class II mesio-occlusal-distal cavity was prepared using computer-aided engineering (CAE) software. A bilayer technique was then applied, and 3D FE analyses were performed under polymerization contraction loading. Glass ionomer composites (Vitrebond and Ionosit) and flowable composite resin (Luxa Flow and Z350 Flowable Restorative) were used as lining materials. Moreover, several sensitivity analyses with dozens of hypothetical lining materials were conducted to provide definitive results. The thickness of the base layers was set to be distinct (0.5 mm or 1 mm) so as to reveal its effect on the stress alleviation. Various lining strategies with the liner covering different areas of the cavity walls (Closed Sandwich, Open Sandwich and Special Open Sandwich) were adopted to determine the effects of the base layers. RESULTS Adoption of an appropriate liner could effectively reduce the polymerization shrinkage stress. The mechanical properties of the base layer can affect the residual stresses, basically a lower Young's modulus and lower Poisson's ratio (of lining material) result in better stress mitigation, therefore reducing the stress transmitted to the dentin. Increase of the lining thickness within a certain range could lead to a decrease in the probability of stress concentration formation. Lining strategies had the strongest influence on the stress distributions. Different lining coverage could cause various stress responses, and covering all cavity walls with the lining material had the optimal performance among all the simulations in this study. SIGNIFICANCE The multilayer technique is an effective way to prolong the service life of resin composites restorations. A thorough evaluation of the sandwich technique through the FE method can provide a better understanding of the stress distributions of the restoration, and reveal its internal mechanisms.
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Affiliation(s)
- Tinghui Sun
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, 610065, China; Yibin Institute of Industrial Technology/Sichuan University Yibin Park, Yibin, 644600, China
| | - Bingmei Shao
- Basic Mechanics Lab, Sichuan University, Chengdu, 610211, China; Yibin Institute of Industrial Technology/Sichuan University Yibin Park, Yibin, 644600, China.
| | - Zhan Liu
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, 610065, China; Yibin Institute of Industrial Technology/Sichuan University Yibin Park, Yibin, 644600, China.
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Effect of Shrinking and No Shrinking Dentine and Enamel Replacing Materials in Posterior Restoration: A 3D-FEA Study. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11052215] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The aim of the present study was to investigate the effect of shrinking and no shrinking dental filling materials combination in posterior restorations under the combined effects of polymerization shrinkage and occlusal load by means of 3D Finite Elements Analysis. Six computer-generated and restored class I or class II cavities models of a lower molar were designed in the CAD software and evaluated according to the cavity and restorative procedure. Different shrinking and no shrinking adhesive materials combination with diverse Young’s modulus were considered. A food bolus was modeled on the occlusal surface replicating the chewing load using static linear analyses Polymerization shrinkage was simulated for the shrinking different restorative materials. The maximum principal stress was selected as analysis criteria. All models exhibited higher stresses along the dentine restoration interfaces with different magnitude and a similar stress trend along enamel restoration interface. Stress values up to 22 MPa and 19 MPa were recorded in the enamel and restoration, respectively. The use of elastic not shrinking material layer in combination with bulk fill composite reduced the stress magnitude in dentine and enamel to replace dental tissues. Class I and class II posterior cavities adhesively restored with shrinking filling material’s combination showed the most unfavorable stress concentrations and the multilayer technique is a promising restorative alternative in posterior adhesive restorations when deep dentin and enamel volumes are missing.
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Kim SY, Kim BS, Kim H, Cho SY. Occlusal stress distribution and remaining crack propagation of a cracked tooth treated with different materials and designs: 3D finite element analysis. Dent Mater 2021; 37:731-740. [PMID: 33589271 DOI: 10.1016/j.dental.2021.01.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/19/2020] [Accepted: 01/20/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Here we used 3D finite element analysis (FEA) to analyze and directly compare stress distribution and crack propagation in identical cracked tooth models after treatment with various materials and designs. METHODS A 3D model of a cracked tooth was generated. We then applied eight restoration models, comprising combinations of three kinds of restoration designs (inlay, onlay, and crown) and four types of restoration materials (direct composite resin, indirect composite resin, ceramic, and gold). A 1000-N occlusal load was applied on the three reference points of the ball-shaped part in the direction of the longitudinal axis, causing crack line separation in the buccolingual direction. Stress distribution was analyzed on the occlusal surface, bottom level of the restoration, and mesiodistal longitudinal section. The stress on the lower margin of the crack surface was measured at 15 points on each model. RESULTS Ceramic inlay and onlay showed stress concentration at the restoration bottom, and low stress on the lower margin of the crack surface. Direct and indirect resin restorations exhibited low stress on the restoration bottom, and high stress on the proximal end of the lower margin of the crack surface. With a resin-unfilled gold crown, stress was concentrated on the crown bottom and the lower margin of the crack surface. Direct resin filling inside the gold crown yielded significantly decreased stress on both areas. SIGNIFICANCE Our results suggest that inlay and onlay ceramic restorations, and gold crown with resin filling inside, are advantageous methods for preventing further crack propagation.
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Affiliation(s)
- Sin-Young Kim
- Department of Conservative Dentistry, Seoul St. Mary's Dental Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 06591, Republic of Korea.
| | - Ban-Suk Kim
- Department of Conservative Dentistry, Seoul St. Mary's Dental Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 06591, Republic of Korea.
| | - Hakjin Kim
- Convert., Ltd., Suite 705, Bodeumgwan, Kangwon National University, Chuncheon-si, Gangwon-do 24341, Republic of Korea.
| | - Sin-Yeon Cho
- Department of Conservative Dentistry, National Health Insurance Service Ilsan Hospital, 100, Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do 10444, Republic of Korea.
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Substantial regional differences in the biomechanical behavior of molar treated with selective caries tissue removal technique: a finite element study. Dent Mater 2021; 37:e162-e175. [PMID: 33358015 DOI: 10.1016/j.dental.2020.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 08/07/2020] [Accepted: 11/13/2020] [Indexed: 12/27/2022]
Abstract
OBJECTIVES Selective caries removal (SCR) is recommended over non-selective removal for managing deep carious lesions to avoid pulp exposure and maintain pulp vitality. During SCR, residual carious dentin is left behind and sealed beneath the restoration. The biomechanical effects of such residual lesions on the restored tooth remain unclear and were assessed using finite element modeling (FEM). METHODS Based on μ-CT images of a healthy permanent human third molar, we developed five finite element models. Generic class I and II cavity restorations were modeled where residual lesions of variable sizes were either left or fully removed on occlusal and proximal surfaces. The cavities were restored with adhesive composite. All 3D-FE models were compared with a model of a healthy, non-treated molar. A vertical load of 100 N was applied onto the occlusal surface. RESULTS Regardless of the lesion size, in molars with occlusal lesions higher mean stresses were predicted along the filling-lesion interface than in all other models. The smallest occlusal lesion (Ø1 = 1 mm) resulted in the highest maximum stresses at the filling-lesion interface with large stress concentrations at the filling walls indicating failure risk. In conclusion, lesion site and extent are influencing parameters affecting the filling-lesion interactions and thus the biomechanical behavior of the tooth after SCR. SIGNIFICANCE Retaining carious lesions around the pulpal floor affects the deformation and stress states in tooth-filling complexes. The higher stresses observed in molars with occlusal lesions may affect restoration stability and longevity. Suprisingly, more extended occlusal lesions may provide a more favorable tooth performance than less extended ones. In contrast, in molars with proximal lesions the residual lesion had only limited effect on the tooth's biomechanical condition.
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Al Mortadi N, Bataineh K, Al Janaideh M. <p>Fatigue Failure Load of Molars with Thin-Walled Prosthetic Crowns Made of Various Materials: A 3D-FEA Theoretical Study</p>. Clin Cosmet Investig Dent 2020; 12:581-593. [PMID: 33376410 PMCID: PMC7759726 DOI: 10.2147/ccide.s286826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/21/2020] [Indexed: 01/22/2023] Open
Affiliation(s)
- Noor Al Mortadi
- Department of Applied Dental Sciences, Jordan University of Science and Technology, Irbid, Jordan
- Correspondence: Noor Al Mortadi Department of Applied Dental Sciences, Jordan University of Science and Technology, P.O. Box (3030), Irbid22110, JordanTel +9627201000 Email
| | - Khaled Bataineh
- Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid, Jordan
| | - Mohammad Al Janaideh
- Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid, Jordan
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Evaluation of the Flexural Strength, Water Sorption, and Solubility of a Glass Ionomer Dental Cement Modified Using Phytomedicine. MATERIALS 2020; 13:ma13235352. [PMID: 33255839 PMCID: PMC7728315 DOI: 10.3390/ma13235352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 11/16/2022]
Abstract
Objectives: Various medicinal plant parts and extracts have been proven to be sources of biologically active compounds, many of which have been incorporated in the production of new pharmaceutical compounds. Thus, the aim of this study was to increase the antimicrobial properties of a glass ionomer cement (GIC) through its modification with a mixture of plant extracts, which were evaluated along with a 0.5% chlorohexidine-modified GIC (CHX-GIC) with regard to the water sorption, solubility, and flexural strength. Methods: Salvadora persica, Olea europaea, and Ficus carcia leaves were prepared for extraction with ethyll alcohol using a Soxhlet extractor for 12 h. The plant extract mixture (PE) was added in three different concentrations to the water used for preparation of a conventional freeze-dried GIC (groups 1:1, 2:1, and 1:2). Specimens were then mixed according to the manufacturer’s instructions and tested against the unmodified GIC (control) and a GIC modified with 0.5% chlorhexidine. Water sorption and solubility were evaluated after 7 days of immersion in distilled water. Flexural strength was evaluated in a three-point bending test after 24 h using a universal material testing machine at a crosshead speed of 1 mm/min. One-way analysis of variance (ANOVA) was used for comparison between the groups. Tukey’s post hoc test was used for pairwise comparison when the ANOVA test was significant. Results: There were no statistically significant differences between the control (M = 20.5%), CHX-GIC (M = 19.6%), 1:1 (M = 20.0%), 1:2 (M = 19.5%), and 2:1 (19.7%) groups with regard to the percentage of water sorption, while for water solubility the 2:1 (M = −0.39%) plant-modified group was significantly different from all of the other groups. Flexural strength test results showed that the 2:1 group (M = 26.1 MPa) recorded significantly higher mean values compared to all other tested groups. Conclusion and clinical relevance: The plant extracts did not negatively affect the water sorption and solubility of the GIC, while the flexural strength was improved by the addition of the plant extract at higher concentrations.
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A standardized method to determine the effect of polymerization shrinkage on the cusp deflection and shrinkage induced built-in stress of class II tooth models. J Mech Behav Biomed Mater 2020; 111:103987. [DOI: 10.1016/j.jmbbm.2020.103987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 06/21/2020] [Accepted: 07/10/2020] [Indexed: 11/19/2022]
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Ausiello P, Ciaramella S, De Benedictis A, Lanzotti A, Tribst JPM, Watts DC. The use of different adhesive filling material and mass combinations to restore class II cavities under loading and shrinkage effects: a 3D-FEA. Comput Methods Biomech Biomed Engin 2020; 24:485-495. [PMID: 33090047 DOI: 10.1080/10255842.2020.1836168] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
3D tooth models were virtually restored: flowable composite resin + bulk-fill composite (A), glass ionomer cement + bulk-fill composite (B) or adhesive + bulk-fill composite (C). Polymerization shrinkage and masticatory loads were simulated. All models exhibited the highest stress concentration at the enamel-restoration interfaces. A and C showed similar pattern with lower magnitude in A in comparison to C. B showed lower stress in dentine and C the highest cusps displacement. The use of glass ionomer cement or flowable composite resin in combination with a bulk-fill composite improved the biomechanical behavior of deep class II MO cavities.
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Affiliation(s)
- P Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - S Ciaramella
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - A De Benedictis
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - A Lanzotti
- Department of Industrial Engineering, Fraunhofer JL IDEAS - University of Naples Federico II, Naples, Italy
| | - J P M Tribst
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, Brazil
| | - D C Watts
- School of Medical Sciences and Photon Science Institute, University of Manchester, Manchester, UK
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Ausiello P, Gloria A, Maietta S, Watts DC, Martorelli M. Stress Distributions for Hybrid Composite Endodontic Post Designs with and without a Ferrule: FEA Study. Polymers (Basel) 2020; 12:E1836. [PMID: 32824363 PMCID: PMC7465202 DOI: 10.3390/polym12081836] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 08/03/2020] [Accepted: 08/13/2020] [Indexed: 02/07/2023] Open
Abstract
The aim of the current work was to analyze the influence of the ferrule effect for hybrid composite endodontic post designs consisting of carbon (C) and glass (G) fiber-reinforced polyetherimide (PEI), in upper canine teeth. Starting from theoretical designs of C-G/PEI hybrid composite posts with different Young's moduli (Post A-57.7 GPa, Post B-31.6 GPa, Post C-graduated from 57.7 to 9.0 GPa in the coronal-apical direction) in endodontically treated anterior teeth, the influence of the ferrule effect was determined through finite element analysis (FEA). On the surface of the crown, a load of 50 N was applied at 45° to the longitudinal axis of the tooth. Maximum principal stresses were evaluated along the C-G/PEI post as well as at the interface between the surrounding tooth structure and the post. Maximum stress values were lower than those obtained for the corresponding models without a ferrule. The presence of a ferrule led to a marked decrease of stress and gradients especially for posts A and B. A less marked effect was globally found for Post C, except in a cervical margin section along a specific direction, where a significant decrease of the stress was probably due to local geometric features, compared to the model without a ferrule. The presence of a ferrule did not generally provide a marked benefit in the case of the graduated Post C, in comparison to other C-G/PEI posts. The outcomes suggest how such a hybrid composite post alone should be sufficient to optimize the stress distribution, dissipating stress from the coronal to the apical end.
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Affiliation(s)
- Pietro Ausiello
- School of Dentistry—University of Naples Federico II, 80131 Naples, Italy;
| | - Antonio Gloria
- Institute of Polymers, Composites and Biomaterials—National Research Council of Italy, 80125 Naples, Italy
| | - Saverio Maietta
- Department of Industrial Engineering, Fraunhofer JL IDEAS—University of Naples Federico II, 80125 Naples, Italy; (S.M.); (M.M.)
| | - David C. Watts
- School of Medical Sciences and Photon Science Institute, University of Manchester, Manchester M13 9PL, UK;
| | - Massimo Martorelli
- Department of Industrial Engineering, Fraunhofer JL IDEAS—University of Naples Federico II, 80125 Naples, Italy; (S.M.); (M.M.)
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Tribst JPM, Dal Piva AMDO, Lo Giudice R, Borges ALS, Bottino MA, Epifania E, Ausiello P. The Influence of Custom-Milled Framework Design for an Implant-Supported Full-Arch Fixed Dental Prosthesis: 3D-FEA Sudy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17114040. [PMID: 32517097 PMCID: PMC7313457 DOI: 10.3390/ijerph17114040] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 11/16/2022]
Abstract
The current study aimed to evaluate the mechanical behavior of two different maxillary prosthetic rehabilitations according to the framework design using the Finite Element Analysis. An implant-supported full-arch fixed dental prosthesis was developed using a modeling software. Two conditions were modeled: a conventional casted framework and an experimental prosthesis with customized milled framework. The geometries of bone, prostheses, implants and abutments were modeled. The mechanical properties and friction coefficient for each isotropic and homogeneous material were simulated. A load of 100 N load was applied on the external surface of the prosthesis at 30° and the results were analyzed in terms of von Mises stress, microstrains and displacements. In the experimental design, a decrease of prosthesis displacement, bone strain and stresses in the metallic structures was observed, except for the abutment screw that showed a stress increase of 19.01%. The conventional design exhibited the highest stress values located on the prosthesis framework (29.65 MPa) between the anterior implants, in comparison with the experimental design (13.27 MPa in the same region). An alternative design of a stronger framework with lower stress concentration was reported. The current study represents an important step in the design and analysis of implant-supported full-arch fixed dental prosthesis with limited occlusal vertical dimension.
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Affiliation(s)
- João Paulo Mendes Tribst
- Department of Dental Materials and Prosthodontics at São Paulo State University (Unesp), Institute of Science and Technology, São Paulo 01049-010, Brazil; (J.P.M.T.); (A.M.d.O.D.P.); (A.L.S.B.); (M.A.B.)
| | - Amanda Maria de Oliveira Dal Piva
- Department of Dental Materials and Prosthodontics at São Paulo State University (Unesp), Institute of Science and Technology, São Paulo 01049-010, Brazil; (J.P.M.T.); (A.M.d.O.D.P.); (A.L.S.B.); (M.A.B.)
| | - Roberto Lo Giudice
- Deptartment of Clinical and Experimental Medicine, Messina University, 98100 Messina, Italy
- Correspondence: ; Tel.: +39-393-439-9197
| | - Alexandre Luiz Souto Borges
- Department of Dental Materials and Prosthodontics at São Paulo State University (Unesp), Institute of Science and Technology, São Paulo 01049-010, Brazil; (J.P.M.T.); (A.M.d.O.D.P.); (A.L.S.B.); (M.A.B.)
| | - Marco Antonio Bottino
- Department of Dental Materials and Prosthodontics at São Paulo State University (Unesp), Institute of Science and Technology, São Paulo 01049-010, Brazil; (J.P.M.T.); (A.M.d.O.D.P.); (A.L.S.B.); (M.A.B.)
| | - Ettore Epifania
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, School of Dentistry, University of Naples Federico II, S, via Sergio Pansini n. 5, 80131 Napoli, Italy; (E.E.); (P.A.)
| | - Pietro Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, School of Dentistry, University of Naples Federico II, S, via Sergio Pansini n. 5, 80131 Napoli, Italy; (E.E.); (P.A.)
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Yu P, Xiong Y, Zhao P, Xu Z, Yu H, Arola D, Gao S. On the wear behavior and damage mechanism of bonded interface: Ceramic vs resin composite inlays. J Mech Behav Biomed Mater 2019; 101:103430. [PMID: 31557660 DOI: 10.1016/j.jmbbm.2019.103430] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/09/2019] [Accepted: 09/12/2019] [Indexed: 02/05/2023]
Abstract
Advances in adhesive technologies have increased indications for the use of inlays. Decrease in the bonded interface integrity due to wear has been cited as the main cause of its failure. However, this process of interface degradation and the influence of inlay material on damage mechanism appear to be poorly understood. Thus, we aimed to compare the wear behavior and interface damage between ceramic and resin composite inlays bonded to enamel under sliding contact and use the experimental findings to support recommendation of the appropriate inlay material. Bonded interface specimens involving tooth enamel and either ceramic or resin composite inlays were prepared and subjected to reciprocating wear tests up to 5×104 cycles. The wear track profiles and morphologies were characterized after increments of cyclic sliding contact using white light interferometry and scanning electron microscopy, respectively. Optical microscopy was used to evaluate sub-surface cracks and their propagation within the samples. A finite element analysis was used to analyze the stress distributions of the bonded interfaces. Composite inlays showed higher wear depth than the ceramic in the early stage (N ≤ 5×102 cycles), while no significant difference was found at the later stage. For ceramic inlay a greater portion of the contact load was concentrated in the ceramic structure, which facilitated cracks and chipping of the ceramic inlay, with rather minimal damage in the adjacent interface and enamel. In contrast, for the resin composite inlay there was larger stress concentrated in the adjacent enamel, which caused the development of cracks and their propagation to the inner enamel. The restoration material could contribute to the stress distribution and extent of damage within enamel-inlay bonded interfaces. A tough ceramic appears to be more effective at protecting the residual dental tissue.
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Affiliation(s)
- Ping Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuhuan Xiong
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Peng Zhao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Zhou Xu
- Shanghai Putuo District Eye & Tooth Disease Control and Prevention Hospital, Shanghai, China
| | - Haiyang Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Dwayne Arola
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA; Departments of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, USA; Departments of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA, USA
| | - Shanshan Gao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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Ausiello P, Ciaramella S, Di Rienzo A, Lanzotti A, Ventre M, Watts DC. Adhesive class I restorations in sound molar teeth incorporating combined resin-composite and glass ionomer materials: CAD-FE modeling and analysis. Dent Mater 2019; 35:1514-1522. [PMID: 31395448 DOI: 10.1016/j.dental.2019.07.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 07/22/2019] [Accepted: 07/22/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To investigate the influence of different resin composite and glass ionomer cement material combinations in a "bi-layer" versus a "single-layer" adhesive technique for class I cavity restorations in molars using numerical finite element analysis (FEA). MATERIALS AND METHODS Three virtual restored lower molar models with class I cavities 4mm deep were created from a sound molar CAD model. A combination of an adhesive and flowable composite with bulk fill composite (model A), of a glass ionomer cement with bulk fill composite (model B) and of an adhesive with bulk fill composite (model C), were considered. Starting from CAD models, 3D-finite element (FE) models were created and analyzed. Solid food was modeled on the occlusal surface and slide-type contact elements were used between tooth surface and food. Polymerization shrinkage was simulated for the composite materials. Physiological masticatory loads were applied to these systems combined with shrinkage. Static linear analyses were carried out. The maximum normal stress criterion was adopted as a measure of potential damage. RESULTS All models exhibited high stresses principally located along the tooth tissues-restoration interfaces. All models showed a similar stress trend along enamel-restoration interface, where stresses up to 22MPa and 19MPa was recorded in the enamel and restoration, respectively. A and C models showed a similar stress trend along the dentin-restoration interface with a lower stress level in model A, where stresses up to 11.5MPa and 7.5MPa were recorded in the dentin and restoration, respectively, whereas stresses of 17MPa and 9MPa were detected for model C. In contrast to A and C models, the model B showed a reduced stress level in dentin, in the lower restoration layer and no stress on the cavity floor. SIGNIFICANCE FE analysis supported the positive effect of a "bi-layer" restorative technique in a 4mm deep class I cavities in lower molars versus "single-layer" bulk fill composite technique.
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Affiliation(s)
- Pietro Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Italy.
| | - Stefano Ciaramella
- Department of Industrial Engineering, Fraunhofer JL IDEAS - University of Naples Federico II, Italy
| | - Alessandra Di Rienzo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Italy
| | - Antonio Lanzotti
- Department of Industrial Engineering, Fraunhofer JL IDEAS - University of Naples Federico II, Italy
| | - Maurizio Ventre
- Department of Chemical, Materials and Industrial Production Engineering, University of Naples Federico II & Center for Advanced Biomaterials for HealthCare@CRIB, Istituto Italiano di Tecnologia, Naples, Italy
| | - David C Watts
- School of Medical Sciences and Photon Science Institute, University of Manchester, United Kingdom
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da Rocha DM, Tribst JPM, Ausiello P, Dal Piva AMDO, da Rocha MC, Di Nicoló R, Borges ALS. Effect of the restorative technique on load-bearing capacity, cusp deflection, and stress distribution of endodontically-treated premolars with MOD restoration. Restor Dent Endod 2019; 44:e33. [PMID: 31485429 PMCID: PMC6713078 DOI: 10.5395/rde.2019.44.e33] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/19/2019] [Accepted: 07/21/2019] [Indexed: 11/11/2022] Open
Abstract
Objectives To evaluate the influence of the restorative technique on the mechanical response of endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. Materials and Methods Forty-eight premolars received MOD preparation (4 groups, n = 12) with different restorative techniques: glass ionomer cement + composite resin (the GIC group), a metallic post + composite resin (the MP group), a fiberglass post + composite resin (the FGP group), or no endodontic treatment + restoration with composite resin (the CR group). Cusp strain and load-bearing capacity were evaluated. One-way analysis of variance and the Tukey test were used with α = 5%. Finite element analysis (FEA) was used to calculate displacement and tensile stress for the teeth and restorations. Results MP showed the highest cusp (p = 0.027) deflection (24.28 ± 5.09 µm/µm), followed by FGP (20.61 ± 5.05 µm/µm), CR (17.72 ± 6.32 µm/µm), and GIC (17.62 ± 7.00 µm/µm). For load-bearing, CR (38.89 ± 3.24 N) showed the highest, followed by GIC (37.51 ± 6.69 N), FGP (29.80 ± 10.03 N), and MP (18.41 ± 4.15 N) (p = 0.001) value. FEA showed similar behavior in the restorations in all groups, while MP showed the highest stress concentration in the tooth and post. Conclusions There is no mechanical advantage in using intraradicular posts for endodontically-treated premolars requiring MOD restoration. Filling the pulp chamber with GIC and restoring the tooth with only CR showed the most promising results for cusp deflection, failure load, and stress distribution.
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Affiliation(s)
| | - João Paulo Mendes Tribst
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, Brazil.,Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Noord-Holland, The Netherlands
| | - Pietro Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, School of Dentistry, University of Naples Federico II, Naples, Italy
| | - Amanda Maria de Oliveira Dal Piva
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, Brazil.,Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Noord-Holland, The Netherlands
| | | | - Rebeca Di Nicoló
- Department of Pediatric and Social Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, Brazil
| | - Alexandre Luiz Souto Borges
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, Brazil
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Waldecker M, Rues S, Rammelsberg P, Bömicke W. Validation of in-vitro tests of zirconia-ceramic inlay-retained fixed partial dentures: A finite element analysis. Dent Mater 2019; 35:e53-e62. [PMID: 30686709 DOI: 10.1016/j.dental.2019.01.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/13/2018] [Accepted: 01/13/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVE In the past, discrepancies between laboratory results and clinical behavior have been observed for all-ceramic restorations. This analysis of fracture resistance of zirconia-based inlay-retained fixed partial dentures (IRFPDs) aimed at identifying correlations between an in-vitro test setup and the clinical situation. The effects of tooth material, tooth mobility, restoration design, load direction, and different cements were taken into account. METHODS The in-vitro test model and IRFPD were reverse engineered (Geomagic DesignX) and meshed predominantly with hexahedral elements (approx. 230,000 elements). Homogenous, linear-elastic behavior was assumed for all materials. On the basis of the calculated stresses (ANSYS 18.2) and already known strength distributions for the restorative materials fracture resistance of the complete restoration and force at initial damage (fracture within the veneer) was estimated on the basis of the principal stress hypothesis. Differences depending on the assumed clinical situation and effects of different variables on fracture resistance were evaluated. RESULTS All variables tested in the finite element analysis affected the calculated fracture resistance of the IRFPD. Use of resin teeth led to an underestimation of fracture resistance by up to -57%, whereas fracture resistance of IRFPDs on metal abutment teeth was close to the clinical reference (-6% to +15%). Good correlation between the clinical scenario and that using metal teeth could only be achieved when the natural resilience of the abutment teeth was simulated. SIGNIFICANCE When testing fracture resistance of zirconia-based IRFPDs, metal abutment teeth in combination with simulated tooth resilience can reflect the clinical situation accurately.
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Affiliation(s)
- M Waldecker
- Department of Prosthodontics, Heidelberg University Hospital, University of Heidelberg, Heidelberg, Germany.
| | - S Rues
- Department of Prosthodontics, Heidelberg University Hospital, University of Heidelberg, Heidelberg, Germany
| | - P Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, University of Heidelberg, Heidelberg, Germany
| | - W Bömicke
- Department of Prosthodontics, Heidelberg University Hospital, University of Heidelberg, Heidelberg, Germany
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Metal Posts and the Effect of Material–Shape Combination on the Mechanical Behavior of Endodontically Treated Anterior Teeth. METALS 2019. [DOI: 10.3390/met9020125] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The control of the process–structure–property relationship of a material plays an important role in the design of biomedical metal devices featuring desired properties. In the field of endodontics, several post-core systems have been considered, which include a wide range of industrially developed posts. Endodontists generally use posts characterized by different materials, sizes, and shapes. Computer-aided design (CAD) and finite element (FE) analysis were taken into account to provide further insight into the effect of the material–shape combination of metal posts on the mechanical behavior of endodontically treated anterior teeth. In particular, theoretical designs of metal posts with two different shapes (conical-tapered and conical-cylindrical) and consisting of materials with Young’s moduli of 110 GPa and 200 GPa were proposed. A load of 100 N was applied on the palatal surface of the crown at 45° to the longitudinal axis of the tooth. Linear static analyses were performed with a non-failure condition. The results suggested the possibility to tailor the stress distribution along the metal posts and at the interface between the post and the surrounding structures, benefiting from an appropriate combination of a CAD-based approach and material selection. The obtained results could help to design metal posts that minimize stress concentrations.
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Tribst JPM, Dal Piva AMDO, Penteado MM, Borges ALS, Bottino MA. Influence of ceramic material, thickness of restoration and cement layer on stress distribution of occlusal veneers. Braz Oral Res 2018; 32:e118. [DOI: 10.1590/1807-3107bor-2018.vol32.0118] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/17/2018] [Indexed: 11/22/2022] Open
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Endocrown restorations: Influence of dental remnant and restorative material on stress distribution. Dent Mater 2018; 34:1466-1473. [DOI: 10.1016/j.dental.2018.06.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/08/2018] [Accepted: 06/07/2018] [Indexed: 11/17/2022]
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CAD-FEA modeling and analysis of different full crown monolithic restorations. Dent Mater 2018; 34:1342-1350. [DOI: 10.1016/j.dental.2018.06.024] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 05/09/2018] [Accepted: 06/07/2018] [Indexed: 11/21/2022]
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Modal analysis for implant stability assessment: Sensitivity of this methodology for different implant designs. Dent Mater 2018; 34:1235-1245. [DOI: 10.1016/j.dental.2018.05.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 05/18/2018] [Accepted: 05/18/2018] [Indexed: 01/03/2023]
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Gloria A, Maietta S, Martorelli M, Lanzotti A, Watts DC, Ausiello P. FE analysis of conceptual hybrid composite endodontic post designs in anterior teeth. Dent Mater 2018; 34:1063-1071. [PMID: 29703402 DOI: 10.1016/j.dental.2018.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 04/08/2018] [Accepted: 04/10/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVES To assess conceptual designs of dental posts consisting of polyetherimide (PEI) reinforced with carbon (C) and glass (G) glass fibers in endodontically treated anterior teeth. METHODS 3D tessellated CAD and geometric models of endodontically treated anterior teeth were generated from Micro-CT scan images. Model C-G/PEI composite posts with different Young's moduli were analyzed by Finite Element (FE) methods post A (57.7GPa), post B (31.6GPa), post C (from 57.7 to 9.0GPa in the coronal-apical direction). A load of 50N was applied at 45° to the longitudinal axis of the tooth, acting on the palatal surface of the crown. The maximum principal stress distribution was determined along the post and at the interface between the post and the surrounding structure. RESULTS Post C, with Young's modulus decreasing from 57.7 to 9.0GPa in the coronal-apical direction, reduced the maximum principal stress distribution in the restored tooth. Post C gave reduced stress and the most uniform stress distribution with no stress concentration, compared to the other C-G/PEI composite posts. SIGNIFICANCE The FE analysis confirmed the ability of the functionally graded post to dissipate stress from the coronal to the apical end. Hence actual (physical) C-G/PEI posts could permit optimization of stress distributions in endodontically treated anterior teeth.
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Affiliation(s)
- Antonio Gloria
- Institute of Polymers, Composites and Biomaterials - National Research Council of Italy, Naples, Italy.
| | - Saverio Maietta
- Department of Industrial Engineering, Fraunhofer JL IDEAS - University of Naples Federico II, Italy.
| | - Massimo Martorelli
- Department of Industrial Engineering, Fraunhofer JL IDEAS - University of Naples Federico II, Italy
| | - Antonio Lanzotti
- Department of Industrial Engineering, Fraunhofer JL IDEAS - University of Naples Federico II, Italy
| | - David C Watts
- School of Medical Sciences and Photon Science Institute, University of Manchester, United Kingdom
| | - Pietro Ausiello
- School of Dentistry - University of Naples Federico II, Italy
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Kantardžić I, Vasiljević D, Lužanin O, Maravić T, Blažić L. Influence of the restorative procedure factors on stress values in premolar with MOD cavity: a finite element study. Med Biol Eng Comput 2018; 56:1875-1886. [DOI: 10.1007/s11517-018-1824-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 03/26/2018] [Indexed: 11/24/2022]
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Calì M, Zanetti EM, Oliveri SM, Asero R, Ciaramella S, Martorelli M, Bignardi C. Influence of thread shape and inclination on the biomechanical behaviour of plateau implant systems. Dent Mater 2018; 34:460-469. [DOI: 10.1016/j.dental.2018.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/14/2018] [Accepted: 01/14/2018] [Indexed: 10/18/2022]
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