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Thadathil Varghese J, Babaei B, Farrar P, Prentice L, Prusty BG. Influence of thermal and thermomechanical stimuli on a molar tooth treated with resin-based restorative dental composites. Dent Mater 2022; 38:811-823. [PMID: 35450702 DOI: 10.1016/j.dental.2022.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 03/14/2022] [Accepted: 04/01/2022] [Indexed: 01/04/2023]
Abstract
OBJECTIVES In-vivo experimental techniques to understand the biomechanical behavior of a restored tooth, under varying oral conditions, is very limited because of the invasive nature of the study and complex tooth geometry structure. Therefore, 3D-Finite element analyses are used to understand the behavior of a restored tooth under varying oral conditions. In this study, the distribution of maximum principal stress (MaxPS) and the location of MaxPS on a restored tooth using six different commercially available dental resin composites under the influence of thermal and thermomechanical stimuli are performed. METHODS An intact tooth was scanned using µ-CT and segmented to obtain separate geometric models of the tooth, including enamel and dentine. Then, a class II mesial-occlusal-distal (MOD) cavity was constructed for the tooth model. The restored tooth model was further meshed and imported to the commercial Finite Element (FE) software ANSYS. Thermal hot and cold stimuli at 50 °C and 2 °C, respectively, were applied on the occlusal and lingual surface of the tooth model with the tooth's ambient temperature set at 37 °C. A uniform loading of 400 N was applied on the occlusal surface of the tooth to imitate the masticatory forces during the cyclic thermal stimuli. RESULTS The results of this study showed that the restorative materials with higher thermal conductivity showed a lower temperature gradient between the restoration and enamel, during the application of thermal stimuli, leading to a higher value of MaxPS on the restoration. Moreover, on applying thermal stimuli, the location of MaxPS at the restoration-enamel junction (REJ) changes based on the value of the coefficient of thermal expansion (CTE). The MaxPS distribution on the application of simultaneous thermal and mechanical stimuli was not only dependent on the elastic modulus of restorative materials but also their thermal properties such as the CTE and thermal conductivity. The weakest part of the restoration was at the REJ, as it experienced the peak stress level during the application of thermomechanical stimuli. SIGNIFICANCE The findings from this study suggest that restorative materials with lower values of elastic modulus, lower coefficient of thermal expansion and higher values of thermal conductivity result in lower stresses on the restoration. The outcomes from this study also suggest that the thermal and mechanical properties of a restorative material can have a considerable effect on the selection of restorative materials by dental clinicians over conventional restorative materials.
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Affiliation(s)
- Jerrin Thadathil Varghese
- School of Mechanical and Manufacturing Engineering, University of New South Wales, NSW 2052, Australia.
| | - Behzad Babaei
- School of Mechanical and Manufacturing Engineering, University of New South Wales, NSW 2052, Australia
| | | | | | - B Gangadhara Prusty
- School of Mechanical and Manufacturing Engineering, University of New South Wales, NSW 2052, Australia; ARC Centre for Automated Manufacture of Advanced Composites, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW 2052, Australia
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Panotopoulos GP, Haidar ZS. Thermal Load and Heat Transfer in Dental Titanium Implants: An Ex Vivo-Based Exact Analytical/Numerical Solution to the ‘Heat Equation’. Dent J (Basel) 2022; 10:dj10030043. [PMID: 35323245 PMCID: PMC8946864 DOI: 10.3390/dj10030043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 01/25/2023] Open
Abstract
Introduction: Heat is a kinetic process whereby energy flows from between two systems, hot-to-cold objects. In oro-dental implantology, conductive heat transfer/(or thermal stress) is a complex physical phenomenon to analyze and consider in treatment planning. Hence, ample research has attempted to measure heat-production to avoid over-heating during bone-cutting and drilling for titanium (Ti) implant-site preparation and insertion, thereby preventing/minimizing early (as well as delayed) implant-related complications and failure. Objective: Given the low bone–thermal conductivity whereby heat generated by osteotomies is not effectively dissipated and tends to remain within the surrounding tissue (peri-implant), increasing the possibility of thermal-injury, this work attempts to obtain an exact analytical solution of the heat equation under exponential thermal-stress, modeling transient heat transfer and temperature changes in Ti implants (fixtures) upon hot-liquid oral intake. Materials and Methods: We, via an ex vivo-based model, investigated the impact of the (a) material, (b) location point along implant length, and (c) exposure time of the thermal load on localized temperature changes. Results: Despite its simplicity, the presented solution contains all the physics and reproduces the key features obtained in previous numerical analyses studies. To the best of our knowledge, this is the first introduction of the intrinsic time, a “proper” time that characterizes the geometry of the dental implant fixture, where we show, mathematically and graphically, how the interplay between “proper” time and exposure time influences temperature changes in Ti implants, under the suitable initial and boundary conditions. This fills the current gap in the literature by obtaining a simplified yet exact analytical solution, assuming an exponential thermal load model relevant to cold/hot beverage or food intake. Conclusions: This work aspires to accurately complement the overall clinical diagnostic and treatment plan for enhanced bone–implant interface, implant stability, and success rates, whether for immediate or delayed loading strategies.
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Affiliation(s)
- Grigorios P. Panotopoulos
- Departamento de Ciencias Físicas, Universidad de la Frontera, Temuco 4811186, Chile;
- BioMAT’X I+D+i (Haidar Lab), Universidad de los Andes, Santiago 7550000, Chile
| | - Ziyad S. Haidar
- BioMAT’X I+D+i (Haidar Lab), Universidad de los Andes, Santiago 7550000, Chile
- Centro de Investigación e Innovación Biomédica (CiiB), Universidad de los Andes, Santiago 7550000, Chile
- Programa de Doctorado en BioMedicina, Facultad de Medicina, Universidad de los Andes, Santiago 7550000, Chile
- Facultad de Odontología, Universidad de los Andes, Santiago 7550000, Chile
- Correspondence: or ; Tel.: +56-2-2618-1372; Fax: +56-2-2214-9468
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Nuamwisudhi P, Jearanaiphaisarn T. Oral Functional Behaviors and Tooth Factors Associated with Cracked Teeth in Asymptomatic Patients. J Endod 2021; 47:1383-1390. [PMID: 34102215 DOI: 10.1016/j.joen.2021.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/27/2021] [Accepted: 05/29/2021] [Indexed: 12/21/2022]
Abstract
INTRODUCTION A cracked tooth may occur due to excessive applied force or tooth weakness. However, there is scant information concerning the cracked tooth risk factors. This study aimed to explore the oral functional behaviors and tooth factors associated with posterior cracked teeth. METHODS Fifty-six patients underwent their oral functional behavior assessment via a questionnaire. The intraoral parameters at the patient level (remaining teeth, occluding tooth pairs, overbite, overjet, and occlusal guidance type) and tooth level (remaining marginal ridge number, restored surface number, restorative materials, and cuspal inclination) were examined. The posterior teeth were stained with methylene blue dye and inspected for cracks using a microscope. The correlations between each patient-level parameter and the cracked tooth number/subject were determined using linear regression analysis. The cracked teeth were matched with their contralateral noncracked teeth, and binary regression analysis was used to analyze the association between tooth-level parameters and a cracked tooth. Multivariate regression analysis was performed if more than 1 parameter had a P value ≤.1. RESULTS One hundred thirty-five cracked teeth were found. Eating hard food was significantly related to the cracked tooth number (P < .05). In molars, the occlusal surface restoration and cuspal inclination were significantly related to a cracked tooth, except the mesiobuccal cusp. In the multivariate analysis, the distolingual cusp inclination significantly predicted a cracked tooth (P < .05). In premolars, the lingual cusp inclination was associated with a cracked tooth (P < .05). CONCLUSIONS Eating hard food, occlusal surface restoration, and steep cuspal inclination were associated with posterior cracked teeth.
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Affiliation(s)
- Pasinee Nuamwisudhi
- Department of Operative Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
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Lithium Disilicate Ceramic Endocrown Biomechanical Response According to Different Pulp Chamber Extension Angles and Filling Materials. MATERIALS 2021; 14:ma14051307. [PMID: 33803194 PMCID: PMC7963147 DOI: 10.3390/ma14051307] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/02/2021] [Accepted: 03/04/2021] [Indexed: 12/28/2022]
Abstract
The purpose of this study is to evaluate the effect of pulp chamber extension angles and filling material mechanical properties on the biomechanical response of a ceramic endocrown. A 3D model of maxillary molar that underwent endodontically treatment was exported to computer aided design software to conduct finite element analysis (FEA). The endocrown model was modified considering different pulp chamber extension angles (right angle; 6°, 12° and 18° of axial divergence). The solids were imported into the computer aided engineering software in Standard for the Exchange of Product Data (STEP) format. Nine different filling materials were simulated to seal the orifice of the root canal system under each endocrown restoration (resin composite, bulk-fill resin composite, alkasite, flowable resin composite, glass ionomer cement, autocured resin-reinforced glass ionomer cement, resin cement, bulk-fill flowable resin composite, zinc oxide cement), totaling 36 models. An axial load (300 N) was applied at the occlusal surface. Results were determined by colorimetric graphs of von-Misses stress (VMS) and Maximum Principal Stress (MPS) on tooth, cement layer, and endocrown restorations. VMS distribution showed a similar pattern between the models, with more stress at the load region for the right-angled endocrowns. The MPS showed that the endocrown intaglio surface and cement layer showed different mechanical responses with different filing materials and pulp chamber angles. The stress peaks plotted in the dispersion plot showed that the filling material stiffness is proportional to the stress magnitude in the endocrown, cement layer and tooth adhesive surface. In addition, the higher the pulp chamber preparation angle, the higher the stress peak in the restoration and tooth, and the lower the stress in the cement layer. Therefore, 6° and 12° pulp chamber angles showed more promising balance between the stresses of the adhesive interface structures. Under the conditions of this study, rigid filling materials were avoided to seal the orifice of root canal system when an endocrown restoration was planned as rehabilitation. In addition, the pulp chamber axial walls were prepared between 6° and 12° of divergence to balance the stress magnitude in the adhesive interface for this treatment modality.
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Tribst JPM, Borges ALS, Silva-Concílio LR, Bottino MA, Özcan M. Effect of Restorative Material on Mechanical Response of Provisional Endocrowns: A 3D-FEA Study. MATERIALS 2021; 14:ma14030649. [PMID: 33572533 PMCID: PMC7866804 DOI: 10.3390/ma14030649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 12/14/2022]
Abstract
The goal of this study was to evaluate the stress distribution in an endocrown restoration according to different provisional restorative materials. An endodontically treated maxillary molar model was selected for conducting the finite element analysis (FEA), with a determined amount of dental remnant of 1.5 mm. The model was imported to the analysis software (ANSYS 19.2, ANSYS Inc., Houston, TX, USA) in STEP format. All contacts were considered perfectly bonded. The mechanical properties of each structure were considered isotropic, linear, elastic, and homogeneous. Three different provisional restorative materials were simulated (acrylic resin, bis-acrylic resin, and resin composite). An axial load (300 N) was applied at the occlusal surface in the center of the restoration. Results were determined by colorimetric stress maps of maximum principal stress, maximum shear stress, and total deformation. The different materials influenced the stress distribution for all structures; the higher the material’s elastic modulus, the lower the stress magnitude on the cement layer. In the present study, all provisional restorative materials showed similar stress patterns in the endocrown and on the cement layer however, with different magnitude. Based on this study limitation, the use of resin composite to manufacture provisional endocrowns is suggested as a promising material to reduce the stresses in the cement layer and in the dental tissue surfaces.
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Affiliation(s)
- João Paulo Mendes Tribst
- School of Dentistry, University of Taubaté, Taubaté, São Paulo 12020-340, Brazil; (J.P.M.T.); (L.R.S.-C.)
| | - Alexandre Luiz Souto Borges
- Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo 12220-690, Brazil; (A.L.S.B.); (M.A.B.)
| | | | - Marco Antonio Bottino
- Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo 12220-690, Brazil; (A.L.S.B.); (M.A.B.)
| | - Mutlu Özcan
- Division of Dental Biomaterials, Center for Dental and Oral Medicine, Clinic for Reconstructive Dentistry, University of Zurich, 8032 Zurich, Switzerland
- Correspondence:
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Zhu J, Luo D, Rong Q, Wang X. Effect of biomimetic material on stress distribution in mandibular molars restored with inlays: a three-dimensional finite element analysis. PeerJ 2019; 7:e7694. [PMID: 31565585 PMCID: PMC6745185 DOI: 10.7717/peerj.7694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/19/2019] [Indexed: 11/28/2022] Open
Abstract
Background Although biomimetic material has become increasingly popular in dental cosmetology nowadays, it remains unclear how it would affect the restored teeth during chewing. It is necessary to study the influence of biomimetic material on stress distribution in the restored teeth. Methods Eight three-dimensional finite element (FE) models were constructed and divided into two groups. Group 1 included the FE model of intact molar, and the FE models of inlay-restored molars fabricated from IPS e.max CAD, Lava Ultimate and biomimetic materials individually. Enamel was considered a homogeneous material. Group 2 included the FE models of intact molar and molars restored with inlays using IPS e.max CAD, Lava Ultimate and biomimetic materials individually, considering enamel as an inhomogeneous material. Results In Group 1, compared with that in the intact molar, the maximum tensile stress (MTS) in the occlusal grooves decreased in the inlay-restored molars fabricated from IPS e.max CAD and was concentrated on the cavity floor at the buccal side in the inner dentin around inlay. When Lava Ultimate was selected, MTS decreased in the occlusal grooves and on the cavity floor but increased in the lateral walls. In the restored molar using biomimetic material, the MTS on the cavity floor was distributed more evenly than that in the molar using IPS e.max CAD, and no obvious changes were noted in the lateral walls. The same changes were observed in Group 2. No differences in the stress distribution pattern were noted among the FE models in Groups 1 and 2. Conclusions Molars restored with inlays fabricated from biomimetic material exhibit a more uniform stress distribution in the dentin around restoration. The consideration of enamel as a homogeneous tissue is acceptable for analyzing the maximum principal stress distribution in the inlay-restored molar.
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Affiliation(s)
- Junxin Zhu
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Danmei Luo
- Department of Mechanics and Engineering Science, Peking University, Beijing, China
| | - Qiguo Rong
- Department of Mechanics and Engineering Science, Peking University, Beijing, China
| | - Xiaoyan Wang
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, China
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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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