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Wiedenmann F, Pfefferle R, Reichert A, Jerman E, Stawarczyk B. Impact of high-speed sintering, layer thickness and artificial aging on the fracture load and two-body wear of zirconia crowns. Dent Mater 2020; 36:846-853. [PMID: 32414506 DOI: 10.1016/j.dental.2020.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 03/18/2020] [Accepted: 04/13/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To investigate the impact of high-speed sintering, layer thickness and artificial aging in a chewing simulator on the fracture load (FL) and two-body wear (2BW) of 4Y-TZP crowns. METHODS 4Y-TZP crowns (Ceramill Zolid HT+, Amann Girrbach AG) in three different layer thicknesses (0.5, 1.0, 1.5; N=192, n=64/group) were manufactured using CAD/CAM technology and sintered at 1580°C (high-speed sintering) or 1450°C (control group). Specimens were polished in two-steps and bonded to standardized CoCr abutments with Multilink Automix (Ivoclar Vivadent). 2BW after 6000 thermo- and 1,200,000 chewing-cycles employing enamel antagonists was determined using best fit machining. FL was tested before and after artificial aging. Univariate ANOVAs, post hoc Scheffé, unpaired t-, Kruskal-Wallis- and Mann-Whitney-U-test were computed (p<0.05). RESULTS High-speed sintering resulted in less 2BW of the zirconia than the control group (p=0.013). High-speed sintering (p=0.001-0.006) and an increase in layer thickness (p<0.001-0.012) resulted in higher FL values, while artificial aging led to a reduction of FL (p<0.001). SIGNIFICANCE As high-speed sintering resulted in less two-body wear of the zirconia and comparable or even higher fracture load results than the control group, this cost- and time efficient alternative presents promising mechanical results.
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Affiliation(s)
- Felicitas Wiedenmann
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336 Munich, Germany.
| | - Regina Pfefferle
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336 Munich, Germany
| | - Axel Reichert
- Research & Development, Amann Girrbach GmbH, Herrschaftswiesen 1, 6842 Koblach, Austria
| | - Eva Jerman
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336 Munich, Germany
| | - Bogna Stawarczyk
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336 Munich, Germany
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102
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Jansen van Vuuren L, Jansen van Vuuren WA, Broadbent JM, Duncan WJ, Waddell JN. Development of a bite force transducer for measuring maximum voluntary bite forces between individual opposing tooth surfaces. J Mech Behav Biomed Mater 2020; 109:103846. [PMID: 32543410 DOI: 10.1016/j.jmbbm.2020.103846] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 05/03/2020] [Accepted: 05/04/2020] [Indexed: 12/13/2022]
Abstract
Bite forces are studied in order to understand a wide range of factors pertaining to the mastication system. Various strain gauge transducers have been employed to measure bite forces, with several descriptions of these available in the literature; unfortunately, many reports provide insufficient detail to enable accurate reproduction. The aim of this project was to develop a bite force transducer with the capability of measuring maximum voluntary bite forces between individual opposing tooth surfaces. Furthermore, in an attempt to address the issue of vague device descriptions in the available literature, a detailed account of the transducer development has been included. A novel strain gauge transducer was designed and built. Bite forces of forty individuals were measured to verify the capabilities and clinical application of the device.
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Affiliation(s)
- L Jansen van Vuuren
- Department of Oral Rehabilitation, Faculty of Dentistry, Sir John Walsh Research Institute, Otago University, New Zealand.
| | - W A Jansen van Vuuren
- Department of Oral Rehabilitation, Faculty of Dentistry, Sir John Walsh Research Institute, Otago University, New Zealand
| | - J M Broadbent
- Department of Oral Sciences, Faculty of Dentistry, Sir John Walsh Research Institute, Otago University, New Zealand
| | - W J Duncan
- Department of Oral Sciences, Faculty of Dentistry, Sir John Walsh Research Institute, Otago University, New Zealand
| | - J N Waddell
- Department of Oral Rehabilitation, Faculty of Dentistry, Sir John Walsh Research Institute, Otago University, New Zealand
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Hara K, Namiki C, Yamaguchi K, Kobayashi K, Saito T, Nakagawa K, Ishii M, Okumura T, Tohara H. Association between myotonometric measurement of masseter muscle stiffness and maximum bite force in healthy elders. J Oral Rehabil 2020; 47:750-756. [PMID: 32232877 DOI: 10.1111/joor.12968] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/02/2020] [Accepted: 03/11/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Maximum bite force (MBF) is a common and useful index of masticatory function; it correlates with physical strength in elderly people. Palpation of stiffness in the masseter muscle during forceful biting has been considered to be associated with MBF. However, this assessment method relies on subjective judgments; no study has verified the relationship between MBF and quantitative measurements of masseter muscle stiffness (MMS). OBJECTIVE We aimed to verify the association between masseter muscle myotonometric assessment results and MBF. METHODS In total, 117 community-dwelling >65-year-old individuals from the Tokyo metropolitan area were assessed. MMS on the dominant side during forceful biting was measured with a MyotonPRO device. Masseter muscle thickness (MMT) during rest and forceful biting was measured with an ultrasonic diagnostic apparatus, and the difference in MMT (DMMT) between the rest and forceful biting conditions was determined. MBF data were obtained with a pressure-sensitive sheet and an associated device. To determine the independent variables affecting MBF and MMS, multivariate linear regression analyses with adjustments for age, sex and number of teeth were performed. RESULTS The multivariate analysis revealed that MBF correlated with the number of teeth (β = .489, P < .001) and MMS (β = .259, P = .003) (R2 = .433). MMS correlated with MBF (β = .308, P = .003) and DMMT (β = .430, P < .001) (R2 = .326). CONCLUSION Masseter muscle stiffness possibly reflects a force generated by the masseter muscle during forceful biting. Therefore, MMS is effective to assess tooth loss as well as an index of masseter muscle strength when evaluating MBF.
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Affiliation(s)
- Koji Hara
- Division of Gerontology and Gerodontology, Department of Dysphagia Rehabilitation, Tokyo Medical and Dental University, Tokyo, Japan
| | - Chizuru Namiki
- Division of Gerontology and Gerodontology, Department of Dysphagia Rehabilitation, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kohei Yamaguchi
- Division of Gerontology and Gerodontology, Department of Dysphagia Rehabilitation, Tokyo Medical and Dental University, Tokyo, Japan
| | | | | | - Kazuharu Nakagawa
- Division of Gerontology and Gerodontology, Department of Dysphagia Rehabilitation, Tokyo Medical and Dental University, Tokyo, Japan
| | - Miki Ishii
- Division of Gerontology and Gerodontology, Department of Dysphagia Rehabilitation, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takuma Okumura
- Division of Gerontology and Gerodontology, Department of Dysphagia Rehabilitation, Tokyo Medical and Dental University, Tokyo, Japan
| | - Haruka Tohara
- Division of Gerontology and Gerodontology, Department of Dysphagia Rehabilitation, Tokyo Medical and Dental University, Tokyo, Japan
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Zacher J, Bauer R, Strasser T, Rosentritt M. Laboratory performance and fracture resistance of CAD/CAM implant-supported tooth-coloured anterior FDPs. J Dent 2020; 96:103326. [PMID: 32201200 DOI: 10.1016/j.jdent.2020.103326] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/05/2020] [Accepted: 03/18/2020] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVES This study investigated the in-vitro performance and fracture force of anterior implant-supported tooth-coloured fixed dental prosthesis (FDPs). Different material types with varying flexural strength and modulus of elasticity were compared with screw-retained or bonded application. MATERIALS AND METHODS Identical anterior FDPs (tooth 11-13; n = 80) from materials (flexural strength 240-1150 MPa, modulus 7.6-210 GPa; 1x lithiumdisilicate ceramic, 2x zirconia (4Y-TZP, 5Y-FSZ), 3x resin-based composites (with different flexural strength and modulus)) were milled. FDPs were grouped into chairside (bonded) and labside (screw-retained) procedure. To simulate a 5-year clinical application, thermal cycling with mechanical loading (TCML) was accomplished. TCML-performance and fracture force were evaluated and failure patterns were analysed. Data were statistically investigated (Kolmogorov-Smirnov-test, one-way-ANOVA; post-hoc-Bonferroni, α = 0.05). RESULTS TCML did not lead to any cracks, fractures or chipping on all tested FDPs. Fracture values varied between 1208.9 ± 354.6 N (experimental resin-based composite) and 2094.3 ± 293.4 N (4Y-TZP) for FDPs without screw channel. With screw channel the results ranged between 1297.9 ± 268.3 N (5Y-FSZ) and 2129.3 ± 321.7 N (4Y-TZP). The influence of the screw channel was not significant for all materials (p ≥ 0.218). Modulus of elasticity and flexural strength had influence on the fracture force only in the individual material groups. Fractures at the connector were predominant for ceramic and zirconia. Resin-based composites primarily showed radial fractures in abutment region or mixed failure types. FDPs with/without screw-channel showed comparable types of failure. CONCLUSIONS TCML did not lead to drop-outs or failures for all FDPs. Individual materials showed no different in-vitro performance, but varying fracture force after TCML. Independent from material, screw channels did not weaken the FDPs. All tested systems showed sufficient properties for an anterior implant application.
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Affiliation(s)
- Julian Zacher
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany.
| | - Robert Bauer
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany
| | - Thomas Strasser
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany
| | - Martin Rosentritt
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany
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Manns A, Rojas V, Van Diest N, Rojas D, Sampaio C. Comparative study of molar and incisor bite forces regarding deciduous, mixed, and definitive dentition. Cranio 2020; 40:373-380. [PMID: 32114958 DOI: 10.1080/08869634.2020.1732569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To compare maximum incisor (MBFinc) and molar (MBFmol) bite forces regarding the type of dentition and sex and to establish a relationship between them. METHODS One hundred-five individuals were divided into 3 groups: G1 - 22 females/13 males (4-5 years); G2 - 15 females/20 males (11-12 years); and G3 - 16 females/19 males (17- 18 years). The maximum bite force was recorded with an extraoral measuring device. Three measurements were recorded: right and left molar level (MBFmol) and incisor level (MBFinc). The ratio %MBFinc/MBFmol was determined. RESULTS MBFmol and MBFinc values increased with age (p < 0.05). MBFmol showed statistically higher values than MBFinc (p < 0.05), when compared within the same group. CONCLUSION MBFinc and MBFmol increased with age. For all groups, MBFmol showed higher values than MBFinc, and %MBFinc/MBFmol ratio was 1:2. No differences were found in maximum bite force between sexes.
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Affiliation(s)
- Arturo Manns
- Department of Restorative Dentistry and Oral Function, Universidad De Los Andes, Santiago, Chile
| | - Víctor Rojas
- Department of Orthodontics, Restorative Dentistry and Oral Function, Universidad De Los Andes, Santiago, Chile
| | | | | | - Camila Sampaio
- Department of Restorative Dentistry and Oral Function, Universidad De Los Andes, Santiago, Chile
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Sedrez-Porto JA, Münchow EA, Cenci MS, Pereira-Cenci T. Which materials would account for a better mechanical behavior for direct endocrown restorations? J Mech Behav Biomed Mater 2020; 103:103592. [PMID: 32090921 DOI: 10.1016/j.jmbbm.2019.103592] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 01/22/2023]
Abstract
PURPOSE To investigate the mechanical performance and fracture behavior of endocrown restorations prepared using different composite materials and following a direct technique. METHODS Sound molars were cut at 2 mm above the cementoenamel junction, endodontically treated, and allocated according to the type of restoration (n = 7): without post (endocrowns) or with post (post-retained restorations). Endocrowns were fabricated with conventional composite (Filtek Z350); bulk fill composite (Filtek Bulk Fill); conventional composite modeled using resin adhesives (SBMP: Scotchbond Multipurpose Adhesive; or SBU: Scotchbond Universal Adhesive); and lithium disilicate ceramic (E.max; Positive control). The post-retained restorations were fabricated with glass-fiber post combined with conventional or bulk fill composites. All restorations were bonded following an etch-and-rise adhesive approach or self-adhesive resin cement. The teeth were submitted to fatigue (Byocycle) and compression (EMIC DL500) testing at a crosshead speed of 1 mm/min. Data were analyzed with ANOVA and Tukey (p < 0.05) and Weibull analysis was carried out in order to evaluate the reliability of restorations. RESULTS The bulk-fill-based endocrown showed a stronger performance than the control. The presence of SBMP or the use of bulk-fill composite resulted in the occurrence of less aggressive fractures than the other restorative systems. Endocrowns bonded directly to the tooth seemed to produce similar fracture strength properties as compared to endocrowns bonded using self-adhesive resin cementation. The bulk-fill-based endocrown showed the greatest reliability of study. CONCLUSION Resin-based restorative materials seem to be interesting alternative options to fabricate large dental restorations in lieu of the more traditionally used glass ceramics or root canal post systems.
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Affiliation(s)
| | - Eliseu Aldrighi Münchow
- Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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107
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Arita S, Gonda T, Togawa H, Maeda Y, Ikebe K. Influence of mandibular free-end partial edentulism on the force exerted on maxillary anterior teeth. J Prosthodont Res 2020; 64:454-459. [PMID: 32061570 DOI: 10.1016/j.jpor.2019.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 11/16/2019] [Accepted: 12/12/2019] [Indexed: 11/17/2022]
Abstract
PURPOSE The purpose of this study was to determine the influence of mandibular free-end partial edentulism and the wearing of removable partial dentures in the partially edentulous area on the force exerted on maxillary anterior teeth. METHODS A commercially available jaw model with exchangeable teeth was used. Seven experimental conditions of mandibular free-end edentulism were set up and a distal extension removable partial denture to replace missing posterior teeth was fabricated. Strain gauges were attached to the root surface of the maxillary left central incisor, canine, first premolar and first molar, and the force exerted on them was calculated based on the calibration coefficient. An occlusal load of 49 N was applied and the forces were compared with the Kruskal-Wallis test (P < 0.05). RESULTS The force exerted on the maxillary anterior teeth increased significantly as the number of remaining teeth decreased. The force exerted on the maxillary anterior teeth decreased significantly with use of a removable partial denture. CONCLUSIONS When the number of remaining teeth decreases in mandibular free-end partial edentulism, the burden on the maxillary anterior teeth increases. Our findings suggest that for patients with mandibular free-end partial edentulism, wearing a removable partial denture is effective in preserving the remaining teeth by reducing excessive stress.
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Affiliation(s)
| | - Tomoya Gonda
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Japan.
| | - Hitomi Togawa
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Japan
| | - Yoshinobu Maeda
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Japan
| | - Kazunori Ikebe
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Japan
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108
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Winter A, Schurig A, Rasche E, Rösner F, Kanus L, Schmitter M. The flexural strength of CAD/CAM polymer crowns and the effect of artificial ageing on the fracture resistance of CAD/CAM polymer and ceramic single crowns. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2019; 31:9. [PMID: 31872290 DOI: 10.1007/s10856-019-6347-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES The purpose of this study was to investigate the fracture resistance, flexural strength and Weibull modulus of an innovative CAD/CAM polymer and to compare its fracture resistance with that of glass ceramics. MATERIALS AND METHODS A total of 32 (n = 16 IPS e.max CAD (LIDI); n = 16 LuxaCam Composite (LUXA)) first mandibular molar crowns were fabricated and cemented onto metal dies by use of luting composite. Half of the specimens were loaded until fracture without prior artificial ageing. The other half were subjected to thermal (5°/55 °C) and mechanical (1,200,000 cycles, 80 N) cycling before fracture loading. Scanning electron microscopy was used to analyse fracture behaviour. A three-point bending test of the flexural strength of LUXA was performed according to ISO 6872:2008. Data were analysed by means of the Kolmogorov-Smirnov test, Mann-Whitney U-test (p < 0.05) and Weibull statistical analysis. RESULTS Initial fracture resistance of LIDI was significantly higher than that of LUXA. However, the initial fracture resistance of LIDI decreased significantly after artificial ageing. After ageing, fracture resistance was 1050.29 ± 325.08 N for LUXA and 1250.09 ± 32.53 N for LIDI. Three-point bending test yielded a mean flexural strength value for LUXA of 145.28 ± 18.21 MPa and a Weibull modulus of m = 9.51. CONCLUSIONS Polymer-based material tested in this study had a lower fracture resistance than that of the glass-ceramic material. Fracture resistance and flexural strength of LuxaCam Composite are sufficient for use in the first molar region. CLINICAL RELEVANCE The mechanical properties of this innovative polymer-based material indicate it can be used in the first molar region as a suitable alternative to glass ceramics. Further clinical studies are required to confirm this. The study presents an innovative material as an alternative to glassceramic for the clinical use in dentistry. The materials investigated were differently affected by artificial aging. Clinical use for patients with bruxism may be considered.
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Affiliation(s)
- Anna Winter
- Department of Prosthodontics, Julius Maximilians University Würzburg, Würzburg, Germany.
| | - Axel Schurig
- Department of Prosthodontics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Engelke Rasche
- Department of Prosthodontics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Franziska Rösner
- Department of Prosthodontics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Lisa Kanus
- Department of Prosthodontics, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Marc Schmitter
- Department of Prosthodontics, Julius Maximilians University Würzburg, Würzburg, Germany
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109
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Ketel EC, de Wijk RA, de Graaf C, Stieger M. Relating oral physiology and anatomy of consumers varying in age, gender and ethnicity to food oral processing behavior. Physiol Behav 2019; 215:112766. [PMID: 31812520 DOI: 10.1016/j.physbeh.2019.112766] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/11/2019] [Accepted: 12/04/2019] [Indexed: 12/12/2022]
Abstract
The aim of this study was to link parameters describing oral physiology and anatomy of consumers varying in age, gender and ethnicity to food oral processing behavior. Three groups of healthy consumers were compared: Dutch, Caucasian adults (18-30 yrs, n =32), Chinese, Asian adults (18-30 yrs, n =32) and Dutch, Caucasian older adults (65-85 yrs, n =32). Mastication performance, salivary flow rate (stimulated and unstimulated) and dental status were quantified to characterize oral physiology. Volume of oral cavity, tongue dimensions, facial anthropometry, height and weight were quantified to characterize anatomy. Oral processing behavior of three solid foods (carrot, cheese and sausage) was quantified by video recordings and eating rate (g/s), average consumption time (s), chews per bite (-) and average bite size (g) were determined. Dutch, Caucasian older adults had smaller volume of oral cavity, lower number of teeth and larger head width compared to Dutch, Caucasian adults. Chinese, Asian adults showed significantly higher mastication performance and larger head width compared to Dutch, Caucasian consumers, while dental status did not significantly differ between groups. Males had significantly larger volumes of oral cavity and larger head height and width compared to females. Dutch, Caucasian adults had a shorter average consumption time (s), less chews per bite and consumed the three foods with higher eating rate (g/s) compared to Dutch, Caucasian older adults. Chinese, Asian adults had a significantly longer average consumption time (s), more chews per bite, smaller average bite size (g) and lower eating rate (g/s) compared to Dutch, Caucasian adults. Twenty-one significant relationships were found between oral physiological and anatomical parameters and oral processing behavior. Body weight resulted in the largest β-values, indicating to be the anatomical parameter of largest influence on oral processing behavior. We conclude that only few oral physiological and anatomical parameters related with food oral processing behavior. We suggest that other factors, including cultural factors contribute to variation in food oral processing behavior between different consumer groups more than saliva flow, volume of oral cavity, mastication performance and dental status.
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Affiliation(s)
- Eva C Ketel
- TiFN, P.O. Box 557, AN Wageningen 6700, the Netherlands; Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands.
| | - Rene A de Wijk
- TiFN, P.O. Box 557, AN Wageningen 6700, the Netherlands; Food and Biobased Research, Wageningen University, Wageningen, the Netherlands
| | - Cees de Graaf
- Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands
| | - Markus Stieger
- TiFN, P.O. Box 557, AN Wageningen 6700, the Netherlands; Division of Human Nutrition and Health, Wageningen University, Wageningen, the Netherlands
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110
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Jansen van Vuuren L, Broadbent JM, Duncan WJ, Waddell JN. Maximum voluntary bite force, occlusal contact points and associated stresses on posterior teeth. J R Soc N Z 2019. [DOI: 10.1080/03036758.2019.1691612] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Ludwig Jansen van Vuuren
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
- Department of Oral Rehabilitation, University of Otago, Dunedin, New Zealand
| | - Jonathan M. Broadbent
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
- Department of Oral Sciences, University of Otago, Dunedin, New Zealand
| | - Warwick J. Duncan
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
- Department of Oral Sciences, University of Otago, Dunedin, New Zealand
| | - John N. Waddell
- Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand
- Department of Oral Rehabilitation, University of Otago, Dunedin, New Zealand
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111
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Rosentritt M, Krifka S, Strasser T, Preis V. Fracture force of CAD/CAM resin composite crowns after in vitro aging. Clin Oral Investig 2019; 24:2395-2401. [PMID: 31712983 DOI: 10.1007/s00784-019-03099-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 09/26/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The aim of this in vitro study was to investigate the influence of material, preparation, and pre-treatment on the aging and fracture force of CAD/CAM resin composite molar crowns. MATERIALS AND METHODS CAD/CAM molar crowns (n = 80) were milled from four resin composites (Block HC, Shofu; Lava Ultimate, 3 M; Grandio Blocs, Voco; and Tetric CAD, Ivoclar Vivadent, with/without sandblasting). Extracted human teeth were prepared with optimal preparation (height 6-8 mm, angle 6-8°) or worst-case preparation (height 3.5-4 mm, angle 10-15°). Both groups were prepared with a 1-mm deep cervical circular shoulder. Crowns were adhesively bonded after corresponding tooth treatment required for the individual adhesive systems (Table 1). Specimens were aged for 90 days in water storage (37 °C) and subsequently subjected to thermal cycling and mechanical loading (TCML 3000 × 5 °C/3000 × 55 °C, 2 min each cycle, H20 distilled; 1.2 × 106 cycles à 50 N, 1.6 Hz). De-bonding and fracture force was determined. STATISTICS one-way-ANOVA; post hoc Bonferroni, α = 0.05. RESULTS Four crowns of Lava Ultimate with worst-case preparation de-bonded during TCML. Individual crowns without sandblasting treatment (3x Tetric CAD with optimal preparation; 1x Tetric CAD with worst-case preparation) de-bonded during water storage. One crown of Grandio Blocs with optimal preparation showed a small chipping during TCML. All other crowns survived TCML and water storage without failure. Fracture forces differed between 1272 ± 211 N (Lava Ultimate) and 3061 ± 521 N (Tetric CAD). All Grandio Blocs and Tetric CAD crowns revealed significantly (p ≤ 0.023) higher fracture forces than Block HC or Lava Ultimate crowns. No significantly different (p > 0.05) fracture forces were found between optimal or worst-case preparation/fit groups. CONCLUSIONS De-bonding during water storage and TCML was dependent on material and crown pre-treatment. Therefore, surface roughening seems strongly required. Fracture forces were not influenced by preparation but by the type of material. CLINICAL RELEVANCE Clinical success and de-bonding of CAD/CAM resin composite crowns is strongly influenced by the type of material and its pre-treatment.
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Affiliation(s)
- Martin Rosentritt
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany.
| | - Stefanie Krifka
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany
| | - Thomas Strasser
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany
| | - Verena Preis
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany
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112
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Jin HY, Teng MH, Wang ZJ, Li X, Liang JY, Wang WX, Jiang S, Zhao BD. Comparative evaluation of BioHPP and titanium as a framework veneered with composite resin for implant-supported fixed dental prostheses. J Prosthet Dent 2019; 122:383-388. [DOI: 10.1016/j.prosdent.2019.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/01/2019] [Accepted: 03/04/2019] [Indexed: 12/13/2022]
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113
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Abstract
Enamel is the hardest and most resilient tissue in the human body. Enamel includes morphologically aligned, parallel, ∼50 nm wide, microns-long nanocrystals, bundled either into 5-μm-wide rods or their space-filling interrod. The orientation of enamel crystals, however, is poorly understood. Here we show that the crystalline c-axes are homogenously oriented in interrod crystals across most of the enamel layer thickness. Within each rod crystals are not co-oriented with one another or with the long axis of the rod, as previously assumed: the c-axes of adjacent nanocrystals are most frequently mis-oriented by 1°-30°, and this orientation within each rod gradually changes, with an overall angle spread that is never zero, but varies between 30°-90° within one rod. Molecular dynamics simulations demonstrate that the observed mis-orientations of adjacent crystals induce crack deflection. This toughening mechanism contributes to the unique resilience of enamel, which lasts a lifetime under extreme physical and chemical challenges.
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114
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Are Increased Masticatory Forces Risk for Primary 2nd Molars without Successors? A 3D FEA Study. J Clin Pediatr Dent 2019; 43:64-68. [PMID: 30520701 DOI: 10.17796/1053-4625-43.1.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE Persistent primary teeth with healthy crown-root structures and acceptable functional and esthetic properties may be preserved over a long-term period if needed. However, they may experience root resorption, ankylosis or infraocclusion especially in the second or third decades of life. Despite a lack of sufficient detailed data, increases in occlusal forces by age are known to cause destructive stresses on root surfaces and periodontal tissue. The aim of this study was to evaluate the effect of increasing occlusal forces on mandibular persistent primary molars by using 3D finite element analysis. STUDY DESIGN The impact of increased masticatory forces on compressive and tensile stresses in tooth and surrounding tissue was simulated in two different models (simulating child and adult mouths) by using 3D finite element analysis. RESULTS In both models, the stress values increased by age and compressive stresses were seen on internal root surfaces, while the tensile stresses focused on the furcation area and external root surfaces. CONCLUSION It was concluded that practices such as reducing occlusal surface width may be used to diminish the occlusal forces for long-term tooth survival in persistent primary molars.
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115
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El Ghoul W, Özcan M, Silwadi M, Salameh Z. Fracture resistance and failure modes of endocrowns manufactured with different CAD/CAM materials under axial and lateral loading. J ESTHET RESTOR DENT 2019; 31:378-387. [DOI: 10.1111/jerd.12486] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/28/2019] [Accepted: 04/09/2019] [Indexed: 01/10/2023]
Affiliation(s)
- Wiam El Ghoul
- Lebanese UniversityFaculty of Dental Medicine, Department of Prosthodontics Beirut Lebanon
| | - Mutlu Özcan
- University of ZurichCenter for Dental and Oral Medicine, Division of Dental Biomaterials Zurich Switzerland
| | - Munir Silwadi
- Lebanese UniversityFaculty of Dental Medicine, Department of Prosthodontics Beirut Lebanon
| | - Ziad Salameh
- Lebanese UniversityFaculty of Dental Medicine, Department of Prosthodontics Beirut Lebanon
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Bertrand B, Cunha E, Bécart A, Gosset D, Hédouin V. Age at death estimation by cementochronology: Too precise to be true or too precise to be accurate? AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 169:464-481. [DOI: 10.1002/ajpa.23849] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/14/2019] [Accepted: 04/19/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Benoit Bertrand
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
- Muséum national d'Histoire naturelle, Département Homme et EnvironnementUMR 7194 ‐ HNHP, Institut de Paléontologie Humaine F‐75013 Paris France
| | - Eugenia Cunha
- Laboratory of Forensic AnthropologyCentre for Functional Ecology, Department of Life Sciences, University of Coimbra Coimbra Portugal
- National Institute of Legal Medicine and forensic SciencesLargo da Sé Nova Coimbra Portugal
| | - Anne Bécart
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
| | - Didier Gosset
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
| | - Valery Hédouin
- Univ. Lille, CHU Lille, EA 7367 ‐ UTML ‐ Unité de Taphonomie Médico‐Légale F‐59000 Lille France
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117
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de Kuijper M, Gresnigt M, van den Houten M, Haumahu D, Schepke U, Cune MS. Fracture Strength of Various Types of Large Direct Composite and Indirect Glass Ceramic Restorations. Oper Dent 2019; 44:433-442. [PMID: 30702412 DOI: 10.2341/18-111-l] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
INTRODUCTION The objective of this study was to investigate the mechanical behavior of severely compromised endodontically treated molars restored by means of various types of composite buildups, full-contour lithium disilicate crowns (with or without post) or a lithium disilicate endocrown. METHODS AND MATERIALS One hundred five sound molars were endodontically treated and randomly assigned to 1 control group (endodontic access cavity only) and 6 experimental groups (n=15): glass fiber reinforced composite (GFRC group), direct microhybrid composite (C group), direct microhybrid composite restoration with glass fiber post (CP group), composite buildup and full-contour lithium disilicate crown (LDS group), additional glass fiber post (P-LDS group), and endocrown (EC group). Molar crowns in the treatment groups were removed 1 mm above the cementoenamel junction and restored. All specimens were thermomechanically aged (1.2×106 cycles at 1.7 Hz/50N, 8000 cycles 5°C to 55°C) and axially loaded until failure. Data were analyzed using analysis of variance and Tukey post hoc test (α=0.05). RESULTS Fracture strength was significantly affected by the type of restoration (p=0.000; statistically similar groups identified with superscript letters): LDSB (3217±1052 N), P-LDSAB (2697±665 N), ECAB (2425±993 N), CA (2192±752), controlA (1890±774 N), CPA (1830±590 N), and GFRCA (1823±911 N). Group GFRC obtained significantly more repairable fractures than the other groups. CONCLUSIONS Significant differences in fracture strength were obtained between LDS, the composite restorations, and control group. Direct composite restorations showed similar fracture strength as P-LDS and EC. Incorporating a glass fiber reinforced composite resulted in significantly more repairable failures.
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Todic J, Martinovic B, Pavlovic J, Tabakovic S, Staletovic M. Assessment of the impact of temporomandibular disorders on maximum bite force. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2019; 163:274-278. [PMID: 30631208 DOI: 10.5507/bp.2019.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 01/03/2019] [Indexed: 11/23/2022] Open
Abstract
AIM Temporomandibular disorders (TMD) refer to functional disorders of the masticatory system, temporomandibular joint (TMJ) and masticatory muscles. The main objective of this study was to determine whether and to what extent temporomandibular disorders (TMD) affect the maximum bite force (MBF). METHODS The present study included subjects with and without temporomandibular disorder. The presence of TMD was assessed by means of the Helkimo clinical dysfunction index analysis. We measured the maximum bite pressure (MBP) and occlusal contact area (OCA) by means of a Fuji Prescale Pressure measurement film. Based on the MBP and OCA values obtained, MBF values were determined. RESULTS The MBF values were significantly lower in patients with TMD compared to subjects without TMD (P Conclusion: TMDs have a significant impact on MBF and masticatory muscle action potential. More research is needed to determine the impact of reduced maximum bite force on the functional efficiency of the masticatory system.
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Affiliation(s)
- Jelena Todic
- Department of Prosthodontics, Medical Faculty Pristina in Kosovska Mitrovica, Kosovska Mitrovica, Serbia
| | - Brankica Martinovic
- Department of Pediatric and Preventive Dentistry, Medical Faculty Pristina in Kosovska Mitrovica, Kosovska Mitrovica, Serbia
| | - Jasna Pavlovic
- Department of Orthodontics, Medical Faculty Pristina in Kosovska Mitrovica, Kosovska Mitrovica, Serbia
| | - Sasa Tabakovic
- Department of Maxillofacial Surgery, Medical Faculty Pristina in Kosovska Mitrovica, Kosovska Mitrovica, Serbia
| | - Milos Staletovic
- Department of Prosthodontics, Medical Faculty Pristina in Kosovska Mitrovica, Kosovska Mitrovica, Serbia
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SEDREZ-PORTO JA, MÜNCHOW EA, VALENTE LL, CENCI MS, PEREIRA-CENCI T. New material perspective for endocrown restorations: effects on mechanical performance and fracture behavior. Braz Oral Res 2019; 33:e012. [DOI: 10.1590/1807-3107bor-2019.vol33.0012] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 01/10/2019] [Indexed: 01/06/2023] Open
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120
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Hara K, Tohara H, Kenichiro K, Yamaguchi K, Ariya C, Yoshimi K, Nakane A, Minakuchi S. Association between tongue muscle strength and masticatory muscle strength. J Oral Rehabil 2018; 46:134-139. [DOI: 10.1111/joor.12737] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 09/10/2018] [Accepted: 10/15/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Koji Hara
- Department of Gerodontology; Division of Gerontology and Gerodontology; Tokyo Medical and Dental University; Tokyo Japan
| | - Haruka Tohara
- Department of Gerodontology; Division of Gerontology and Gerodontology; Tokyo Medical and Dental University; Tokyo Japan
| | | | - Kohei Yamaguchi
- Department of Gerodontology; Division of Gerontology and Gerodontology; Tokyo Medical and Dental University; Tokyo Japan
| | - Chantaramanee Ariya
- Department of Gerodontology; Division of Gerontology and Gerodontology; Tokyo Medical and Dental University; Tokyo Japan
| | - Kanako Yoshimi
- Department of Gerodontology; Division of Gerontology and Gerodontology; Tokyo Medical and Dental University; Tokyo Japan
| | - Ayako Nakane
- Department of Gerodontology; Division of Gerontology and Gerodontology; Tokyo Medical and Dental University; Tokyo Japan
| | - Shunsuke Minakuchi
- Department of Gerodontology; Division of Gerontology and Gerodontology; Tokyo Medical and Dental University; Tokyo Japan
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121
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Kondo T, Komine F, Honda J, Takata H, Moriya Y. Effect of veneering materials on fracture loads of implant-supported zirconia molar fixed dental prostheses. J Prosthodont Res 2018; 63:140-144. [PMID: 30446411 DOI: 10.1016/j.jpor.2018.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/25/2018] [Accepted: 10/29/2018] [Indexed: 11/29/2022]
Abstract
PURPOSE To determine the effect of veneering material and framework design on fracture loads of implant-supported zirconia molar fixed dental prostheses (FDPs). METHODS Sixty-six zirconia FDPs were manufactured onto two implants and classified as uniform thickness (UT) or anatomic design (AD). These framework design groups were then further divided into three subgroups (n=11): feldspathic porcelain-veneered zirconia FDPs (PVZ), indirect composite-veneered zirconia FDPs (IVZ), and metal-ceramic FDPs (MC). The FDPs were luted on the implant abutments and underwent fracture load testing. Significant differences were assessed by the Kruskal-Wallis test and Mann-Whitney U-test (α=0.05). RESULTS For UT group, median fracture load was significantly higher for the IVZ (1.87kN) and MC (1.90kN) specimens than for the PVZ specimens (1.38kN) (p<0.05). In the AD group, the IVZ specimens had the highest median fracture load (4.10kN) of the three groups tested. The AD group exhibited higher median fracture loads than the UT group in all subgroups. CONCLUSIONS Indirect composite appears to be a useful alternative to feldspathic porcelain as the layering material for implant-supported zirconia FDPs. The AD group had higher fracture loads than UT group. In addition, implant-supported indirect composite-veneered zirconia-based FDPs appear to be clinically feasible.
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Affiliation(s)
- Tomohide Kondo
- Department of Fixed Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan
| | - Futoshi Komine
- Department of Fixed Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan.
| | - Junichi Honda
- Department of Fixed Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan
| | - Hiroki Takata
- Department of Fixed Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan
| | - Yuta Moriya
- Department of Fixed Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan
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122
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Development of the jaw sensorimotor control and chewing - a systematic review. Physiol Behav 2018; 194:456-465. [DOI: 10.1016/j.physbeh.2018.06.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/21/2018] [Accepted: 06/25/2018] [Indexed: 11/20/2022]
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123
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Characterisation of machinable structural polymers in restorative dentistry. Dent Mater 2018; 34:1509-1517. [DOI: 10.1016/j.dental.2018.06.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/15/2018] [Accepted: 06/07/2018] [Indexed: 11/20/2022]
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Preis V, Hahnel S, Behr M, Rosentritt M. In vitro performance and fracture resistance of novel CAD/CAM ceramic molar crowns loaded on implants and human teeth. J Adv Prosthodont 2018; 10:300-307. [PMID: 30140397 PMCID: PMC6104500 DOI: 10.4047/jap.2018.10.4.300] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/07/2018] [Accepted: 05/08/2018] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To investigate the fatigue and fracture resistance of computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic molar crowns on dental implants and human teeth. MATERIALS AND METHODS Molar crowns (n=48; n=8/group) were fabricated of a lithium-disilicate-strengthened lithium aluminosilicate glass ceramic (N). Surfaces were polished (P) or glazed (G). Crowns were tested on human teeth (T) and implant-abutment analogues (I) simulating a chairside (C, crown bonded to abutment) or labside (L, screw channel) procedure for implant groups. Polished/glazed lithium disilicate (E) crowns (n=16) served as reference. Combined thermal cycling and mechanical loading (TC: 3000×5℃/3000×55℃; ML: 1.2×106 cycles, 50 N) with antagonistic human molars (groups T) and steatite spheres (groups I) was performed under a chewing simulator. TCML crowns were then analyzed for failures (optical microscopy, SEM) and fracture force was determined. Data were statistically analyzed (Kolmogorow-Smirnov, one-way-ANOVA, post-hoc Bonferroni, α=.05). RESULTS All crowns survived TCML and showed small traces of wear. In human teeth groups, fracture forces of N crowns varied between 1214±293 N (NPT) and 1324±498 N (NGT), differing significantly (P≤.003) from the polished reference EPT (2044±302 N). Fracture forces in implant groups varied between 934±154 N (NGI_L) and 1782±153 N (NPI_C), providing higher values for the respective chairside crowns. Differences between polishing and glazing were not significant (P≥.066) between crowns of identical materials and abutment support. CONCLUSION Fracture resistance was influenced by the ceramic material, and partly by the tooth or implant situation and the clinical procedure (chairside/labside). Type of surface finish (polishing/glazing) had no significant influence. Clinical survival of the new glass ceramic may be comparable to lithium disilicate.
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Affiliation(s)
- Verena Preis
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, Regensburg, Germany
| | - Sebastian Hahnel
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, Regensburg, Germany
| | - Michael Behr
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, Regensburg, Germany
| | - Martin Rosentritt
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, Regensburg, Germany
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FEM Investigation of the Stress Distribution over Mandibular Bone Due to Screwed Overdenture Positioned on Dental Implants. MATERIALS 2018; 11:ma11091512. [PMID: 30142897 PMCID: PMC6164220 DOI: 10.3390/ma11091512] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/13/2018] [Accepted: 08/21/2018] [Indexed: 11/16/2022]
Abstract
The objective of the present investigation was to evaluate how dental implant positioning can influence the masticatory stress distribution over screwed mandibular prosthodontics restoration and over the surrounding bone tissue. Moreover, the dental implant components and overdenture bar strengths under masticatory cycles have been investigated in order to evaluate possible screw and prosthesis breakage. A "virtual jaw" model and 3D dental implant were reproduced to realise finite element analysis in order to underline the parameters and the mechanical characteristics of the bone and of the dental implants connected to the overdenture bar. The distribution of a nonspecific chewing phase, analysing the overall load on the fixtures of the lower jaw, was performed. The study investigating frontal and horizontal planes and vertical directions of occlusal forces showed how position and perspective of fixtures strongly influenced the stress distribution and the consequent jawbone tissue remodelling. Prostheses elements such as cantilever, passing screws, and dental implants are strictly related to the correct selection of dental implant position. This study suggested a virtual method to guide the surgeon in the choice of implant number, position, diameter, and length, and cantilever length and shape, and to evaluate the prospective stress distribution of chewing strengths for a correct prosthesis rehabilitation.
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126
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Röhrle O, Saini H, Lee PVS, Ackland DC. A novel computational method to determine subject-specific bite force and occlusal loading during mastication. Comput Methods Biomech Biomed Engin 2018; 21:453-460. [PMID: 30010417 DOI: 10.1080/10255842.2018.1479744] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The evaluation of three-dimensional occlusal loading during biting and chewing may assist in development of new dental materials, in designing effective and long-lasting restorations such as crowns and bridges, and for evaluating functional performance of prosthodontic components such as dental and/or maxillofacial implants. At present, little is known about the dynamic force and pressure distributions at the occlusal surface during mastication, as these quantities cannot be measured directly. The aim of this study was to evaluate subject-specific occlusal loading forces during mastication using accurate jaw motion measurements. Motion data was obtained from experiments in which an individual performed maximal effort dynamic chewing cycles on a rubber sample with known mechanical properties. A finite element model simulation of one recorded chewing cycle was then performed to evaluate the deformation of the rubber. This was achieved by imposing the measured jaw motions on a three-dimensional geometric surface model of the subject's dental impressions. Based on the rubber's deformation and its material behaviour, the simulation was used to compute the resulting stresses within the rubber as well as the contact pressures and forces on the occlusal surfaces. An advantage of this novel modelling approach is that dynamic occlusal pressure maps and biting forces may be predicted with high accuracy and resolution at each time step throughout the chewing cycle. Depending on the motion capture technique and the speed of simulation, the methodology may be automated in such a way that it can be performed chair-side. The present study demonstrates a novel modelling methodology for evaluating dynamic occlusal loading during biting or chewing.
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Affiliation(s)
- Oliver Röhrle
- a Institute of Applied Mechanics (Civil Engineering) , University of Stuttgart , Stuttgart , Germany.,b Cluster of Excellence for Simulation Technology (SimTech) , Stuttgart , Germany.,c Biomechatronic Systems , Fraunhofer Institute for Manufacturing Engineering and Automation IPA , Stuttgart , Germany
| | - Harnoor Saini
- a Institute of Applied Mechanics (Civil Engineering) , University of Stuttgart , Stuttgart , Germany
| | - Peter V S Lee
- d Department of Biomedical Engineering , The University of Melbourne , Parkville , Australia
| | - David C Ackland
- d Department of Biomedical Engineering , The University of Melbourne , Parkville , Australia
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Weickenmeier J, Jabareen M, Le Révérend BJD, Ramaioli M, Mazza E. Experimental and Numerical Characterization of the Mechanical Masseter Muscle Response During Biting. J Biomech Eng 2018; 139:2649336. [PMID: 28813570 DOI: 10.1115/1.4037592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Indexed: 12/11/2022]
Abstract
Predictive simulations of the mastication system would significantly improve our understanding of temporomandibular joint (TMJ) disorders and the planning of cranio-maxillofacial surgery procedures. Respective computational models must be validated by experimental data from in vivo characterization of the mastication system's mechanical response. The present pilot-study demonstrates the feasibility of a combined experimental and numerical procedure to validate a computer model of the masseter muscle. An experimental setup is proposed that provides a simultaneous bite force measurement and ultrasound-based visualization of muscle deformation. The direct comparison of the experimentally observed and numerically predicted muscle response demonstrates the predictive capabilities of such anatomically accurate biting models. Differences between molar and incisor biting are investigated; muscle deformation is recorded for three different bite forces in order to capture the effect of increasing muscle fiber recruitment. The three-dimensional (3D) muscle deformation at each bite position and force-level is approximatively reconstructed from ultrasound measurements in five distinct cross-sectional areas (four horizontal and one vertical cross section). The experimental work is accompanied by numerical simulations to validate the predictive capabilities of a constitutive muscle model previously formulated. An anatomy-based, fully 3D model of the masseter muscle is created from magnetic resonance images (MRI) of the same subject. The direct comparison of experimental and numerical results revealed good agreement for maximum bite forces and masseter deformations in both biting positions. The present work therefore presents a feasible in vivo measurement system to validate numerically predicted masseter muscle contractions during mastication.
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Affiliation(s)
- J Weickenmeier
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich 8092, Switzerland e-mail:
| | - M Jabareen
- Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - B J D Le Révérend
- Nestlé Research Center, Rte du Jorat 57, CH-1000 Lausanne 26, Lausanne CH-3008, Switzerland
| | - M Ramaioli
- Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - E Mazza
- Swiss Federal Laboratories for Materials Science and Technology-EMPA, Duebendorf 8600, Switzerland.,Department of Mechanical and Process Engineering, ETH Zurich, Zurich 8092, Switzerland
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Weigl P, Sander A, Wu Y, Felber R, Lauer HC, Rosentritt M. In-vitro performance and fracture strength of thin monolithic zirconia crowns. J Adv Prosthodont 2018; 10:79-84. [PMID: 29713427 PMCID: PMC5917110 DOI: 10.4047/jap.2018.10.2.79] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/30/2017] [Accepted: 09/12/2017] [Indexed: 01/19/2023] Open
Abstract
PURPOSE All-ceramic restorations required extensive tooth preparation. The purpose of this in vitro study was to investigate a minimally invasive preparation and thickness of monolithic zirconia crowns, which would provide sufficient mechanical endurance and strength. MATERIALS AND METHODS Crowns with thickness of 0.2 mm (group 0.2, n=32) or of 0.5 mm (group 0.5, n=32) were milled from zirconia and fixed with resin-based adhesives (groups 0.2A, 0.5A) or zinc phosphate cements (groups 0.2C, 0.5C). Half of the samples in each subgroup (n=8) underwent thermal cycling and mechanical loading (TCML)(TC: 5℃ and 55℃, 2×3,000 cycles, 2 min/cycle; ML: 50 N, 1.2×106 cycles), while the other samples were stored in water (37℃/24 h). Survival rates were compared (Kaplan-Maier). The specimens surviving TCML were loaded to fracture and the maximal fracture force was determined (ANOVA; Bonferroni; α=.05). The fracture mode was analyzed. RESULTS In both 0.5 groups, all crowns survived TCML, and the comparison of fracture strength among crowns with and without TCML showed no significant difference (P=.628). Four crowns in group 0.2A and all of the crowns in group 0.2C failed during TCML. The fracture strength after 24 hours of the cemented 0.2 mm-thick crowns was significantly lower than that of adhesive bonded crowns. All cemented crowns provided fracture in the crown, while about 80% of the adhesively bonded crowns fractured through crown and die. CONCLUSION 0.5 mm thick monolithic crowns possessed sufficient strength to endure physiologic performance, regardless of the type of cementation. Fracture strength of the 0.2 mm cemented crowns was too low for clinical application.
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Affiliation(s)
- Paul Weigl
- Head of Department of Postgraduate Education, Carolinum Dental University Institute gGmbH, Department of Prosthetic Dentistry, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Anna Sander
- Department of Prosthetic Dentistry, Faculty of Oral and Dental Medicine at JW Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Yanyun Wu
- Department of Postgraduate Education, Faculty of Oral and Dental Medicine at JW Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Roland Felber
- Department of Postgraduate Education, Carolinum Dental University Institute gGmbH, Department of Prosthetic Dentistry, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Hans-Christoph Lauer
- Head of Department of Prosthetic Dentistry, Carolinum Dental University Institute gGmbH, Department of Prosthetic Dentistry, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Martin Rosentritt
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, Regensburg, Germany
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Dizdarevic D, Masic T, Muslic E. Lower Jaw Grip Strength in Healthy and Sick Population Measured by Special Force Transducer. Acta Inform Med 2017; 25:236-239. [PMID: 29284912 PMCID: PMC5723165 DOI: 10.5455/aim.2017.25.236-239] [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] [Indexed: 11/22/2022] Open
Abstract
Introduction: One of the basic chronic diseases of the MFH domain that is treated on an outpatient basis is temporomandibular dysfunction (TMD). It represents a number of pathological conditions that lead to the dysfunction of the normal function of the stomatognatic system. Observing the etiologic factors of this condition, temporomandibular TM trauma, poor habits such as infantile type of swallowing, tongue depression, and tectogenic disturbance of the myofunctional squamous system are reported in order to reconstruct the defects of neighboring regions. Material and Methods: The study included 60 patients divided into 3 groups: Group I without predetermined temporomandibular dysfunction, Group II with TMD, and Group III where one of the muscles of the masticatory group was used during the reconstruction procedure. Results: Statistically obtained results show that in group III there is a large difference in postoperative measurement after 6 weeks. Discussion: In the mentioned patients divided into three groups, the measurement of the pressure strength expressed in N follows certain states with it measured values, which coincides with comparative studies. Conclusion: From the obtained results we conclude that the parameter used, the strength of the lower jaw bite is a significant indicator of the chewing system functioning.
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Affiliation(s)
- Dino Dizdarevic
- Clinic of Maxillofacial Surgery, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Tarik Masic
- Clinic of Maxillofacial Surgery, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Edi Muslic
- Clinic for Plastic and Reconstructive Surgery, Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina
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130
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Choi S, Yoon HI, Park EJ. Load-bearing capacity of various CAD/CAM monolithic molar crowns under recommended occlusal thickness and reduced occlusal thickness conditions. J Adv Prosthodont 2017; 9:423-431. [PMID: 29279761 PMCID: PMC5741445 DOI: 10.4047/jap.2017.9.6.423] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The goal of this study was to evaluate the fracture resistances of various monolithic crowns fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) with different thickness. MATERIALS AND METHODS Test dies were fabricated as mandibular molar forms with occlusal reductions using CAD/CAM. With different occlusal thickness (1.0 or 1.5 mm), a polymer-infiltrated ceramic network (Enamic, EN), and zirconia-reinforced lithium silicate (Suprinity, SU and Celtra-Duo, CD) were used to fabricate molar crowns. Lithium disilicate (e.max CAD, EM) crowns (occlusal: 1.5 mm) were fabricated as control. Seventy crowns (n=10 per group) were bonded to abutments and stored in water for 24 hours. A universal testing machine was used to apply load to crown until fracture. The fractured specimens were examined with a scanning electron microscopy. RESULTS The type of ceramics and the occlusal thickness showed a significant interaction. With a recommended thickness (1.5 mm), the SU revealed the mean load similar to the EM, higher compared with those of the EN and CD. The fracture loads in a reduced thickness (1.0 mm) were similar among the SU, CD, and EN. The mean fracture load of the SU and CD enhanced significantly when the occlusal thickness increased, whereas that of the EN did not. CONCLUSION The fracture loads of monolithic crowns were differently influenced by the changes in occlusal thickness, depending on the type of ceramics. Within the limitations of this study, all the tested crowns withstood the physiological masticatory loads both at the recommended and reduced occlusal
thickness.
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Affiliation(s)
- Sulki Choi
- Graduate School of Clinical Dentistry, Ewha Womans University, Seoul, Republic of Korea
| | - Hyung-In Yoon
- Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Eun-Jin Park
- Department of Prosthodontics, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
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131
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Changes of bite force and occlusal contacts in the retention phase of orthodontic treatment: A controlled clinical trial. Am J Orthod Dentofacial Orthop 2017; 152:767-777. [PMID: 29173856 DOI: 10.1016/j.ajodo.2017.03.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 03/01/2017] [Accepted: 03/01/2017] [Indexed: 11/22/2022]
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132
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CAD–CAM plates versus conventional fixation plates for primary mandibular reconstruction: A biomechanical in vitro analysis. J Craniomaxillofac Surg 2017; 45:1878-1883. [DOI: 10.1016/j.jcms.2017.08.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/19/2017] [Accepted: 08/22/2017] [Indexed: 11/19/2022] Open
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133
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Ozer F, Naden A, Turp V, Mante F, Sen D, Blatz MB. Effect of thickness and surface modifications on flexural strength of monolithic zirconia. J Prosthet Dent 2017; 119:987-993. [PMID: 29042115 DOI: 10.1016/j.prosdent.2017.08.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 08/16/2017] [Accepted: 08/16/2017] [Indexed: 11/30/2022]
Abstract
STATEMENT OF PROBLEM A recommended minimum thickness for monolithic zirconia restorations has not been reported. Assessing a proper thickness that has the necessary load-bearing capacity but also conserves dental hard tissues is essential. PURPOSE The purpose of this in vitro study was to evaluate the effect of thickness and surface modifications on monolithic zirconia after simulated masticatory stresses. MATERIAL AND METHODS Monolithic zirconia disks (10 mm in diameter) were fabricated with 1.3 mm and 0.8 mm thicknesses. For each thickness, 21 disks were fabricated. The specimens of each group were further divided into 3 subgroups (n=7) according to the surface treatments applied: untreated (control), airborne-particle abrasion with 50-μm Al2O3 particles at a pressure of 400 kPa at 10 mm, and grinding with a diamond rotary instrument followed by polishing. The biaxial flexure strength was determined by using a piston-on-3-balls technique in a universal testing machine. Flexural loading was applied with a 1.4-mm diameter steel cylinder, centered on the disk, at a crosshead speed of 0.5 mm/min until fracture occurred. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were performed. The data were statistically analyzed with 2-way ANOVA, Tamhane T2, 1-way ANOVA, and Student t tests (α=.05). RESULTS The 1.3-mm specimens had significantly higher flexural strength than the 0.8-mm specimens (P<.05). Airborne-particle abrasion significantly increased the flexural strength (P<.05). Grinding and polishing did not affect the flexural strength of the specimens (P>.05). CONCLUSIONS The mean flexural strength of 0.8-mm and 1.3-mm thick monolithic zirconia was greater than reported masticatory forces. Airborne-particle abrasion increased the flexural strength of monolithic zirconia. Grinding did not affect flexural strength if subsequently polished.
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Affiliation(s)
- Fusun Ozer
- Associate Professor, University of Pennsylvania School of Dental Medicine, Department of Preventive and Restorative Sciences, Philadelphia, Pa
| | - Andrew Naden
- Predoctoral student, University of Pennsylvania School of Dental Medicine, Department of Preventive and Restorative Sciences, Philadelphia, Pa
| | - Volkan Turp
- Associate Professor, Istanbul University Faculty of Dentistry, Department of Prosthodontics, Istanbul, Turkey.
| | - Francis Mante
- Associate Professor, University of Pennsylvania School of Dental Medicine, Department of Preventive and Restorative Sciences, Philadelphia, Pa
| | - Deniz Sen
- Professor, Istanbul University, Faculty of Dentistry, Department of Prosthetic Dentistry, Istanbul, Turkey
| | - Markus B Blatz
- Professor and Chair, Department of Preventive and Restorative Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, Pa
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134
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Occlusal loading during biting from an experimental and simulation point of view. Dent Mater 2017; 34:58-68. [PMID: 29017762 DOI: 10.1016/j.dental.2017.09.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 09/15/2017] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Occlusal loading during clenching and biting is achieved by the action of the masticatory system, and forms the basis for the evaluation of the functional performance of prosthodontic and maxillofacial components. This review provides an overview of (i) current bite force measurement techniques and their limitations and (ii) the use of computational modelling to predict bite force. A brief simulation study highlighting the challenges of current computational dental models is also presented. METHODS Appropriate studies were used to highlight the development and current bite force measurement methodologies and state-of-the-art simulation for computing bite forces using biomechanical models. RESULTS While a number of strategies have been developed to measure occlusal forces in three-dimensions, the use of strain-gauges, piezo-electric sensors and pressure sheets remain the most widespread. In addition to experimental-based measurement techniques, bite force may be also estimated using computational models of the masticatory system. Simulations of different bite force models clearly show that the use of three-dimensional force measurements enriches the evaluation of masticatory functional performance. SIGNIFICANCE Hence, combining computational modelling with three-dimensional force measurement techniques can significantly improve the evaluation of masticatory system and the functional performance of prosthodontic components.
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135
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Padma S, Umesh S, Asokan S, Srinivas T. Bite force measurement based on fiber Bragg grating sensor. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-6. [PMID: 29090535 DOI: 10.1117/1.jbo.22.10.107002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/11/2017] [Indexed: 06/07/2023]
Abstract
The maximum level of voluntary bite force, which results from the combined action of muscle of mastication, joints, and teeth, i.e., craniomandibular structure, is considered as one of the major indicators for the functional state of the masticatory system. Measurement of voluntary bite force provides useful data for the jaw muscle function and activity along with assessment of prosthetics. This study proposes an in vivo methodology for the dynamic measurement of bite force employing a fiber Bragg grating (FBG) sensor known as bite force measurement device (BFMD). The BFMD developed is a noninvasive intraoral device, which transduces the bite force exerted at the occlusal surface into strain variations on a metal plate. These strain variations are acquired by the FBG sensor bonded over it. The BFMD developed facilitates adjustment of the distance between the biting platform, which is essential to capture the maximum voluntary bite force at three different positions of teeth, namely incisor, premolar, and molar sites. The clinically relevant bite forces are measured at incisor, molar, and premolar position and have been compared against each other. Furthermore, the bite forces measured with all subjects are segregated according to gender and also compared against each other.
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Affiliation(s)
- Srivani Padma
- Indian Institute of Science, Department of Instrumentation and Applied Physics, Bangalore, India
- Indian Institute of Science, Department of Electrical Communication Engineering, Bangalore, India
| | - Sharath Umesh
- Indian Institute of Science, Department of Instrumentation and Applied Physics, Bangalore, India
| | - Sundarrajan Asokan
- Indian Institute of Science, Department of Instrumentation and Applied Physics, Bangalore, India
- Indian Institute of Science, Applied Photonics Initiative, Bangalore, India
| | - Talabattula Srinivas
- Indian Institute of Science, Department of Electrical Communication Engineering, Bangalore, India
- Indian Institute of Science, Applied Photonics Initiative, Bangalore, India
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136
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Verma TP, Kumathalli KI, Jain V, Kumar R. Bite Force Recording Devices - A Review. J Clin Diagn Res 2017; 11:ZE01-ZE05. [PMID: 29207848 DOI: 10.7860/jcdr/2017/27379.10450] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/20/2017] [Indexed: 11/24/2022]
Abstract
In dental research, bite force serves as a valuable parameter to evaluate the efficacy of masticatory system. A variety of devices with different design and working principle have been used to record bite force, but no single device is capable to record all the required forces. One may find it difficult to choose a device that will fulfil the purpose of recording bite force for research. So, the present review aims to report and compare the wide range of devices and will help in describing their uses for recording bite force.
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Affiliation(s)
- Tarun Prakash Verma
- Senior Lecturer, Department of Periodontics, Sri Aurobindo College of Dentistry, Indore, Madhya Pradesh, India
| | | | - Vinay Jain
- Postgraduate Student, Department of Periodontics, Sri Aurobindo College of Dentistry, Indore, Madhya Pradesh, India
| | - Rajesh Kumar
- Reader, Department of Periodontics, Sri Aurobindo College of Dentistry, Indore, Madhya Pradesh, India
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137
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Tasaka A, Kikuchi M, Nakanishi K, Ueda T, Yamashita S, Sakurai K. Psychological stress-relieving effects of chewing - Relationship between masticatory function-related factors and stress-relieving effects. J Prosthodont Res 2017; 62:50-55. [PMID: 28676294 DOI: 10.1016/j.jpor.2017.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 04/07/2017] [Accepted: 05/18/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE The objective of the present study was to investigate the relationship between masticatory function-related factors (masticatory performance, occlusal contact area, maximum bite force, number of chewing strokes, and muscle activity) and the stress-relieving effects of chewing. METHODS A total of 28 healthy male subjects were instructed to rest or chew for 10min after 30min of stress loading with arithmetic calculations. Their stress state was assessed by measuring salivary cortisol levels. Saliva was collected at three time points: before stress loading, immediately after stress loading, and 10min after stress loading. Compared to resting, chewing produced a significantly greater reduction in the rate of change in salivary cortisol levels 10min after stress loading. RESULTS A negative correlation was observed between the rate of decrease in salivary cortisol levels and the number of chewing strokes. No significant correlation was observed between the rate of decrease in salivary cortisol levels and other measurement items. CONCLUSION In healthy dentulous people, the number of chewing strokes has been shown to be a masticatory function-related factor that affects stress relief from chewing, suggesting the possibility that more appropriate chewing would produce a greater effect psychological stress relief.
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Affiliation(s)
- Akinori Tasaka
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan.
| | - Manaki Kikuchi
- Department of Removable Prosthodontics and Gerodontology, Tokyo Dental College, Tokyo, Japan
| | - Kousuke Nakanishi
- Department of Removable Prosthodontics and Gerodontology, Tokyo Dental College, Tokyo, Japan
| | - Takayuki Ueda
- Department of Removable Prosthodontics and Gerodontology, Tokyo Dental College, Tokyo, Japan
| | - Shuichiro Yamashita
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Kaoru Sakurai
- Department of Removable Prosthodontics and Gerodontology, Tokyo Dental College, Tokyo, Japan
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138
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In-vitro fatigue and fracture testing of CAD/CAM-materials in implant-supported molar crowns. Dent Mater 2017; 33:427-433. [DOI: 10.1016/j.dental.2017.01.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/21/2016] [Accepted: 01/18/2017] [Indexed: 10/20/2022]
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139
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Rosentritt M, Raab P, Hahnel S, Stöckle M, Preis V. In-vitro performance of CAD/CAM-fabricated implant-supported temporary crowns. Clin Oral Investig 2017; 21:2581-2587. [PMID: 28110407 DOI: 10.1007/s00784-017-2057-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 01/10/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Martin Rosentritt
- Department of Prosthetic Dentistry, University Medical Center Regensburg, 93042, Regensburg, Germany
| | - Philipp Raab
- Department of Prosthetic Dentistry, University Medical Center Regensburg, 93042, Regensburg, Germany
| | - Sebastian Hahnel
- Department of Prosthetic Dentistry, University Medical Center Regensburg, 93042, Regensburg, Germany
| | - Matthias Stöckle
- Department of Prosthetic Dentistry, University Medical Center Regensburg, 93042, Regensburg, Germany
| | - Verena Preis
- Department of Prosthetic Dentistry, University Medical Center Regensburg, 93042, Regensburg, Germany.
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140
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Denes BJ, Bresin A, Kiliaridis S. The influence of altered functional loading and posterior bite-blocks on the periodontal ligament space and alveolar bone thickness in rats. Acta Odontol Scand 2016; 74:518-524. [PMID: 27462822 DOI: 10.1080/00016357.2016.1211316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVES Posterior bite-blocks are resin-based structures elevating the occlusion and creating intrusive force on the posterior teeth. Bite-blocks were applied to the molars of growing rats and a hard and soft diet was used to create altered functional masticatory forces. The aim of the present investigation was to study the effect of this appliance on the periodontal ligament space and alveolar bone thickness when combined with altered masticatory forces. MATERIAL AND METHODS Fifty-two four-week-old rats were divided into two groups, hard and soft diet. Two weeks later, half of them received a bite-block appliance, creating four groups: control hard (CH), control soft (CS), bite-block hard (BH) and bite-block soft (BS). All were sacrificed at age of 10 weeks. Their heads were scanned by micro-CT and periodontal ligament space (PDL) width, cross-sectional alveolar socket surface and alveolar bone thickness were measured. Analysis of variance (ANOVA) was used to compare the groups. RESULTS The PDL was 9.2% thinner in the CS group (p < 0.001) and 20.7% in the bite-block groups (p < 0.001) compared to the CH group. Within each of the four groups, the mesiodistal PDL space was larger than the palatobuccal. The alveolar bone was thinner by 5.8% (p = 0.018) in the CS group, 10.7% in the BH group (p < 0.001) and 16.7% in the BS group (p < 0.001) compared to the CH group. CONCLUSIONS Young rats wearing posterior bite-blocks have narrower PDL space and thinner alveolar bone compared to controls. When fed a soft diet, the alveolar bone is even thinner but the PDL showed no difference.
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141
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Scudine KGDO, Pedroni-Pereira A, Araujo DS, Prado DGDA, Rossi AC, Castelo PM. Assessment of the differences in masticatory behavior between male and female adolescents. Physiol Behav 2016; 163:115-122. [DOI: 10.1016/j.physbeh.2016.04.053] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
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142
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Iinuma T, Arai Y, Takayama M, Abe Y, Ito T, Kondo Y, Hirose N, Gionhaku N. Association between maximum occlusal force and 3-year all-cause mortality in community-dwelling elderly people. BMC Oral Health 2016; 16:82. [PMID: 27586200 PMCID: PMC5009498 DOI: 10.1186/s12903-016-0283-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/23/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Among the very elderly, poor oral health reduces life expectancy. In this study, differences in the magnitude of the maximum occlusal force (MOF) in the very elderly were examined in terms of effects on all-cause mortality in a 3-year follow-up. METHODS We evaluated 489 community-living elderly individuals aged 85 years or older. MOF was measured using an occlusal force measuring device, and participants were classified into three groups according to gender- and dental status-sensitive tertiles. Demographic variables, cognitive, physical function, psychological status, oral health, comorbidity, and blood chemistry factors were assessed. One-way analyses of variance, χ (2) tests, and the Kruskal-Wallis test were used for statistical analyses. The relationship between MOF tertiles and 3-year all-cause mortality was examined using a multivariate Cox model analysis after adjusting for confounding factors. RESULTS MOF tertiles were significantly associated with cognitive impairment, number of teeth, limitations on chewable foods, handgrip strength, timed up-and-go test, and diabetes mellitus. During the follow-up period, 74 subjects died. Subjects with the highest MOF had a significantly lower mortality rate than other groups (log rank P = 0.031). In the univariate Cox model, MOF tertiles were independently associated with a lower risk of death (HR = 0.69, 95 % CI = 0.51-0.91). Even after adjusting for various confounders in the multivariate Cox model (Model 1), MOF was independently associated with a lower risk of death (HR = 0.67, 95 % CI = 0.50-0.91). In model 2, we added handgrip strength as a confounder and found that the HR for MOF was attenuated (HR = 0.73, 95 % CI = 0.54-0.99), but still statistically significant. CONCLUSIONS In a cohort of the very elderly, MOF was independently associated with all-cause mortality after adjusting for various health issues. Moreover, this independent association remained after a further adjustment for handgrip strength; however, the HR was attenuated. This suggests that MOF and handgrip strength may share a common mechanism of a general decrease in muscle strength, possibly sarcopenia, which is a significant cause of mortality in the very old.
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Affiliation(s)
- Toshimitsu Iinuma
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan.
| | - Yasumichi Arai
- Center for Supercentenarian Medical Research, Keio University School of Medicine, Tokyo, Japan
| | - Michiyo Takayama
- Center for Preventive Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Yukiko Abe
- Center for Supercentenarian Medical Research, Keio University School of Medicine, Tokyo, Japan
| | - Tomoka Ito
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan
| | - Yugaku Kondo
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan
| | - Nobuyoshi Hirose
- Center for Supercentenarian Medical Research, Keio University School of Medicine, Tokyo, Japan
| | - Nobuhito Gionhaku
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan
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143
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Melo DGD, Bianchini EMG. Relationship between electrical activity of the temporal and masseter muscles, bite force, and morphological facial index. Codas 2016; 28:409-16. [PMID: 27556824 DOI: 10.1590/2317-1782/20162014233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 10/05/2015] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To analyze possible correlations between the electrical activity of masseter and temporal muscles, Bite Force (BF), and Morphological Facial Indices (MFI). METHODS The study involved 43 young adults, both genders, 18 to 37 years old. The individuals were submitted to: face measurement to calculate MFI; Masseter and Temporal Surface Electromyography (sEMG) and BF measurements on right and left premolars and incisors. The following electromyographic tests were conducted: at rest position; Maximal Voluntary Isometrical Contraction (MVIC) and usual chewing of raisins. Statistical analysis was conducted using the coefficient of Spearman correlation with significance level of 5%. RESULTS The values at rest in the temporal muscles were significantly higher than those in the masseter muscles. A meaningful correlation was found between MFI and sEMG in the MVIC test for the Left Temporal (rs=36, p=0.017). A significant correlation was observed between FMI and sEMG during BF in incisors for temporal muscles and the Right Masseter. During the force tests, it was possible to observe a meaningful correlation between BF in right premolars and the sEMG of the Left Temporal and Masseters. CONCLUSION No correlation was found between the sEMG of temporal and masseter muscles, BF, and FMI in adult individuals based on the tests performed. The SEMG of temporal and masseter muscles seems to be associated only with BF. As a datum of habitual postural characteristic, the electrical activity of temporal muscles is higher than the activity of masseters, also regardless of MFI.
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Fastier-Wooller J, Phan HP, Dinh T, Nguyen TK, Cameron A, Öchsner A, Dao DV. Novel Low-Cost Sensor for Human Bite Force Measurement. SENSORS 2016; 16:s16081244. [PMID: 27509496 PMCID: PMC5017409 DOI: 10.3390/s16081244] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/01/2016] [Accepted: 08/02/2016] [Indexed: 11/16/2022]
Abstract
This paper presents the design and development of a low cost and reliable maximal voluntary bite force sensor which can be manufactured in-house by using an acrylic laser cutting machine. The sensor has been designed for ease of fabrication, assembly, calibration, and safe use. The sensor is capable of use within an hour of commencing production, allowing for rapid prototyping/modifications and practical implementation. The measured data shows a good linear relationship between the applied force and the electrical resistance of the sensor. The output signal has low drift, excellent repeatability, and a large measurable range of 0 to 700 N. A high signal-to-noise response to human bite forces was observed, indicating the high potential of the proposed sensor for human bite force measurement.
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Affiliation(s)
| | - Hoang-Phuong Phan
- Queensland Micro- and Nanotechnology Centre, Griffith University, Queensland 4111, Australia.
| | - Toan Dinh
- Queensland Micro- and Nanotechnology Centre, Griffith University, Queensland 4111, Australia.
| | - Tuan-Khoa Nguyen
- Queensland Micro- and Nanotechnology Centre, Griffith University, Queensland 4111, Australia.
| | - Andrew Cameron
- School of Dentistry, Griffith University, Queensland 4215, Australia.
| | - Andreas Öchsner
- School of Engineering, Griffith University, Queensland 4215, Australia.
| | - Dzung Viet Dao
- School of Engineering, Griffith University, Queensland 4215, Australia.
- Queensland Micro- and Nanotechnology Centre, Griffith University, Queensland 4111, Australia.
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Abstract
Objective To investigate the association between the health status of permanent first molars and different craniofacial relationships among adolescents. Study design This is a retrospective study on patients’ records aged 11–15 years. Sex, skeletal relationship, vertical growth pattern, malocclusion, overjet, and overbite were assessed. The health status of permanent first molars was recorded from the orthopantomograms and intraoral photographs as “sound” and “not sound”. Chi-square, Mann–Whitney U and Kruskal–Wallis tests, and Pearson’s correlation coefficient were used to analyze and correlate the assessed variables. Significance level was set at P<0.05. Results A total of 210 records were evaluated; 81 were male, 68 had Class I and 91 had Class II skeletal relationships. More than half of the subjects had normal (n=67) to moderate deep bite (n=72); normal (n=91), moderately increased (n=54), to severely increased (n=50) overjet; and Class I (n=106) and Class II division 1 (n=75) malocclusion. Significant differences were found in the health status of the permanent first molars with respect to sex (P=0.034), vertical growth pattern (P=0.01), and overbite (P=0.047). Strong correlations were only found between the health status of the permanent first molars and the following variables: sex (P=0.036) and vertical growth pattern (P=0.004). Significant correlation was further found between the upper left first molar health status and sex (P=0.019) and the lower right first molar health status and the vertical growth pattern (P=0.001). No significant association was found with the anteroposterior craniofacial relationships (P>0.05). Conclusion Sex difference and vertical growth patterns were found to be potential predictors of the health status of the permanent first molars. No significant association was found with the anteroposterior craniofacial relationships.
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Affiliation(s)
- Amal I Linjawi
- Department of Orthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
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146
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Long-Term Fatigue and Its Probability of Failure Applied to Dental Implants. BIOMED RESEARCH INTERNATIONAL 2016; 2016:8927156. [PMID: 27517052 PMCID: PMC4969521 DOI: 10.1155/2016/8927156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/16/2016] [Accepted: 06/22/2016] [Indexed: 11/17/2022]
Abstract
It is well known that dental implants have a high success rate but even so, there are a lot of factors that can cause dental implants failure. Fatigue is very sensitive to many variables involved in this phenomenon. This paper takes a close look at fatigue analysis and explains a new method to study fatigue from a probabilistic point of view, based on a cumulative damage model and probabilistic finite elements, with the goal of obtaining the expected life and the probability of failure. Two different dental implants were analysed. The model simulated a load of 178 N applied with an angle of 0°, 15°, and 20° and a force of 489 N with the same angles. Von Mises stress distribution was evaluated and once the methodology proposed here was used, the statistic of the fatigue life and the probability cumulative function were obtained. This function allows us to relate each cycle life with its probability of failure. Cylindrical implant has a worst behaviour under the same loading force compared to the conical implant analysed here. Methodology employed in the present study provides very accuracy results because all possible uncertainties have been taken in mind from the beginning.
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147
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Honda J, Komine F, Kamio S, Taguchi K, Blatz MB, Matsumura H. Fracture resistance of implant-supported screw-retained zirconia-based molar restorations. Clin Oral Implants Res 2016; 28:1119-1126. [DOI: 10.1111/clr.12926] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Junichi Honda
- Department of Fixed Prosthodontics; Nihon University School of Dentistry; Tokyo Japan
| | - Futoshi Komine
- Department of Fixed Prosthodontics; Nihon University School of Dentistry; Tokyo Japan
| | - Shingo Kamio
- Department of Fixed Prosthodontics; Nihon University School of Dentistry; Tokyo Japan
| | - Kohei Taguchi
- Department of Fixed Prosthodontics; Nihon University School of Dentistry; Tokyo Japan
| | - Markus B. Blatz
- Department of Preventive and Restorative Sciences; University of Pennsylvania School of Dental Medicine; Philadelphia PA USA
| | - Hideo Matsumura
- Department of Fixed Prosthodontics; Nihon University School of Dentistry; Tokyo Japan
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148
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Umesh S, Padma S, Asokan S, Srinivas T. Fiber Bragg Grating based bite force measurement. J Biomech 2016; 49:2877-2881. [PMID: 27432747 DOI: 10.1016/j.jbiomech.2016.06.036] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 06/01/2016] [Accepted: 06/24/2016] [Indexed: 11/28/2022]
Abstract
The present study reports an in vivo, novel methodology for the dynamic measurement of the bite force generated by individual tooth using a Fiber Bragg Grating Bite Force Recorder (FBGBFR). Bite force is considered as one of the major indicators of the functional state of the masticatory system, which is dependent on the craniomandibular structure comprising functional components such as muscles of mastication, joints and teeth. The proposed FBGBFR is an intra-oral device, developed for the transduction of the bite force exerted at the occlusal surface, into strain variations on a base plate, which in turn is sensed by the FBG sensor bonded over it. The FBGBFR is calibrated against a Micro Universal Testing Machine (UTM) for 0-900N range and the resolution of the developed FBGBFR is found to be 0.54N. 36 volunteers (20 males and 16 females) performed the bite force measurement test at molar, premolar and incisor tooth on either side of the dental arch and the obtained results show clinically relevant bite forces varying from 176N to 635N. The bite forces obtained from the current study for a substantial sample size, show that the bite forces increases along the dental arch from the incisors towards the molars and are found to be higher in male than in female. The FBG sensor element utilized in FBGBFR is electrically passive, which makes it a safe in vivo intra-oral device. Hence the FBGBFR is viable to be employed in clinical studies on biomechanics of oral function.
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Affiliation(s)
- Sharath Umesh
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, India
| | - Srivani Padma
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, India; Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, India
| | - Sundarrajan Asokan
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, India.
| | - Talabattula Srinivas
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, India
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149
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Rosentritt M, Hahnel S, Engelhardt F, Behr M, Preis V. In vitro performance and fracture resistance of CAD/CAM-fabricated implant supported molar crowns. Clin Oral Investig 2016; 21:1213-1219. [DOI: 10.1007/s00784-016-1898-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/27/2016] [Indexed: 11/28/2022]
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150
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Di Berardino F, Filipponi E, Schiappadori M, Forti S, Zanetti D, Cesarani A. The occlusal imaging and analysis system by T-scan III in tinnitus patients. Biomed J 2016; 39:139-44. [PMID: 27372169 PMCID: PMC6140139 DOI: 10.1016/j.bj.2016.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 10/05/2015] [Indexed: 11/23/2022] Open
Abstract
Background Several studies have demonstrated that the prevalence of temporomandibular disorders (TMDs) in tinnitus patients ranges from 7% to 95%, and it is reported in literature that idiopathic tinnitus patients should be referred to a dentist to define whether or not the tinnitus is associated with TMD. However, the possible pathophysiological relation between TMDs and tinnitus is not generally investigated in clinical practice. Methods The patterns and forces of occlusal contacts have been studied by means of T-scan III in 47 tinnitus patients (23 suffering from idiopathic tinnitus and 24 affected by Ménière disease [MD]) and 13 healthy subjects. Results The center of force target was offset in the opposite direction in 15/23 idiopathic tinnitus and in 7/24 MD patients (p = 0.026). No significant variation was found in the occlusal force. Conclusions Our data suggest that a diagnostic screening method for occlusal stability in the intercuspidal position might be clinically useful in idiopathic tinnitus patients.
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Affiliation(s)
- Federica Di Berardino
- Department of Clinical Sciences and Community, Audiology Unit, IRCCS Fondazione Policlinico, Mangiagalli e Regina Elena, University of Milan, Milan, Italy.
| | - Eliana Filipponi
- S.I.T.R.A. Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Massimo Schiappadori
- Department of Clinical Sciences and Community, Audiology Unit, IRCCS Fondazione Policlinico, Mangiagalli e Regina Elena, University of Milan, Milan, Italy
| | - Stella Forti
- Department of Clinical Sciences and Community, Audiology Unit, IRCCS Fondazione Policlinico, Mangiagalli e Regina Elena, University of Milan, Milan, Italy
| | - Diego Zanetti
- Department of Clinical Sciences and Community, Audiology Unit, IRCCS Fondazione Policlinico, Mangiagalli e Regina Elena, University of Milan, Milan, Italy
| | - Antonio Cesarani
- Department of Clinical Sciences and Community, Audiology Unit, IRCCS Fondazione Policlinico, Mangiagalli e Regina Elena, University of Milan, Milan, Italy
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