Tooth fracture in vivo and in vitro

Burke, F. J. T.

doi:10.1016/0300-5712(92)90124-u

Cited by 121 publications

(91 citation statements)

References 51 publications

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“…The average occlusal force in the literature is 21.7 kgf (about 212 N). 5 In the region comprising the premolar and molar occlusal areas, these forces vary between 161 N and 351 N, respectively.…”

Section: Discussionmentioning

confidence: 99%

The Influence of Elastic Modulus of Inlay Materials on Stress Distribution and Fracture of Premolars

Costa

Xavier

Noritomi³

et al. 2014

Operative Dentistry

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SUMMARY The purpose of this study was to evaluate the influence the width of the occlusal isthmus and inlay material had on the stress distribution, displacement, and fracture resistance of upper human premolars. For this in vitro test, 35 intact upper premolars (UPM) were selected and five were kept intact for the control group (group I). The remaining 30 were divided into two experimental groups (n=15) according to the width of isthmus: conservative (CP) and extensive preparation (EP), one third and more than two thirds of cuspal distance, respectively. Five teeth from each experimental group were left without restoration for negative controls (CPnc and EPnc), and the remaining 10 in each group were subdivided according to the inlay material (resin or ceramic): group CPr, CP + indirect resin; group CPc, CP + ceramic; group EPr, EP + indirect resin; and group EPc, EP + ceramic. The cemented inlays were loaded in a universal testing machine at a crosshead speed of 0.5 mm/min until fracture. The fractured specimens were analyzed with stereomicroscopy, and the values of the fracture resistance evaluated by analysis of variance and Tukey test. For the finite element analyses, an average UPM for each group was modeled in Rhinoceros CAD software and imported to Ansys 13.0. An average of 320,000 tetrahedral elements and 540,000 nodes for the seven models were performed using the same experimental simulation setup for each. The models were constrained on the base, and a displacement of 0.02 mm was applied to keep a linear behavior for the analysis. A von Mises stress and total displacement fields were used for the coherence test and the maximum principal stress fields were used for mechanical behavior comparisons. Group I (161.73 ± 22.94) showed a significantly higher mean value than the other experimental groups (EPc: 103.55 ± 15.84; CPc: 94.38 ± 12.35; CPr: 90.31 ± 6.10; EPr: 65.42 ± 10.15; CPnc: 65.46 ± 5.37; EPnc: 58.08 ± 9.62). The stress distribution was different in all of the groups. EPnc showed a higher concentration of tensile stress on the cervical region of the proximal box. CPc and EPc provided a lower tensile stress and a smaller cuspal displacement. Within the limits of this study, the configuration of the inlay preparation is a significant factor in the fracture resistance of premolars: the smaller the amount of remaining tooth, the lower the fracture resistance. In addition, the teeth restored with ceramic materials showed a higher fracture resistance than those restored with composite resin.

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Section: Discussionmentioning

confidence: 99%

The Influence of Elastic Modulus of Inlay Materials on Stress Distribution and Fracture of Premolars

Costa

Xavier

Noritomi³

et al. 2014

Operative Dentistry

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“…Cuspal fracture is a natural and deteriorating consequence of tooth weakness and/or parafunctional force, and the study of this phenomenon is thus clinically relevant because it is widely observed in dental practice [20][21][22][23] . The incidence of cuspal fracture has been reported to be frequent in upper premolars 24,25) .…”

Section: Discussionmentioning

confidence: 99%

Effect of bidirectional loading on contact and force characteristics under a newly developed masticatory simulator with a dual-direction loading system

2016

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Mechanical responses of the test specimen under bidirectional and unidirectional loading were investigated using a newly developed masticatory simulator. The simulator adopted a four-bar linkage mechanism to create both loading patterns. Scratch/occlusal contact characteristics, contact force profiles and the fracture of restored tooth samples were investigated. With bidirectional loading, which imitates the nature of human chewing cycle closer than the unidirectional loading does, the occlusal contact was ovoid in shape whereas a small circular area was observed from the test with unidirectional loading. The contact force profiles were also noticeably dependent on the loading patterns. Measured contact forces from bidirectional loading were more uniform than those from unidirectional loading. Bidirectional loading also induced the cuspal fracture with similar characteristics of natural cuspal fractures in humans. The differences of force characteristics between those of bidirectional and unidirectional loadings emphasize the importance of employing bidirectional loading in dental material testing.

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Section: Introductionmentioning

confidence: 99%

“…While it is plausible that fracture in the restored tooth results from a single catastrophic load, it is generally believed that such failures are the result of subcritical cracking induced by repetitive stresses, i.e., fatigue [3]. Damage induced by restorative processes can grow with time due to cyclic stresses resulting from mastication and can enable complete fracture of the tooth [4][5][6][7].A number of in vitro studies on cyclic crack growth in bovine [8][9][10], elephant [11,12] and human dentin [13][14][15] have been conducted in the recent past. These studies have been successful in quantifying the fatigue properties of dentin.…”

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confidence: 99%