Stress Analysis of a Tooth Restored with a Post and Core

An idealized axisymmetric finite element model of a second premolar restored with a post and core was used to study the distribution and magnitude of stresses as a function of the following parameters : the diameter of the post, the length and the shape of the post, and finally the interface characteristics between post and cement. Emphasis was directed toward the cement layer interposed between the post and the tooth. Bonding between the post and the cement appeared to be the most important parameter to achieve optimal mechanical behavior of the tooth-prosthesis combination.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66564/2/10.1177_00220345830620061501.pd

Finite element analysis of three- and four-unit bridges

A two-dimensional finite element model of a mandibular quadrant was used to examine differences in magnitude of the principal stresses from the placement of three- and four-unit bridges. The area of interest spanned the first premolar to the second molar. Loading conditions were (i) vertical and distributed and (ii) 30° to the vertical and concentrated. The principal stresses were calculated and compared for: (i) the first molar removed with the remaining bone either cancellous or cancellous surrounded by a cortical shell; (ii) as in (i) but with the second premolar and first molar removed; (iii) a three-unit bridge spanning the second premolar to the second molar; and (iv) a four-unit bridge spanning the first premolar to the second molar. Each tooth was supported by periodontal ligaments, cortical and cancellous bone with each assigned the appropriate physical constants. Removal of the first molar resulted in considerable variation of the stresses especially when the cortical shell was replaced by cancellous bone. Because of the lower modulus of cancellous bone and its lower load-bearing capabilities the stresses were three to ten times lower and more uniform within the cancellous bone. Generally, the addition of a bridge resulted in lower and better distributed Σ min stresses. The bridge also resulted in higher tensile stresses distal to the abutment teeth which theoretically could result in bone deposition. No significant differences in magnitude were observed between the three- and four-unit bridge. From a stress standpoint the bridges resulted in more uniform stress distribution around the abutments and an increase in the tensile stresses distal to the abutments. Such findings support the placement of a fixed bridge to maintain bone in an edentulous area.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74974/1/j.1365-2842.1989.tb01384.x.pd

Clinical evaluation of Dyract in primary molars : 1-year results

Contains fulltext : 23520.PDF (publisher's version ) (Open Access

Biomechanika van kaviteitspreparatie en -restauratie van gebitselementen: modelvorming en analyse met behulp van de eindige elementen methode

Contains fulltext : mmubn000001_026826755.pdf (publisher's version ) (Open Access)Promotores : A. Plasschaert en J.D. Janssen1 dl. (versch. pag.)

1-Year Clinical-Performance of Dyract Restorative in Deciduous Molars

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