Effect of increased post length due to the presence of the remaining coronal structure on the fracture strength of post-retained restorations.

This study evaluated the effects of the remaining coronal tissue and post type on the fracture strength of incisors. Sixty human maxillary central incisors were sectioned at the cemento-enamel junction or at 2 mm above this junction. The roots received cast cores and posts, fibre posts, or relined fibre posts (n = 10 each). A compressive load was applied over the cores untilfracture. In the absence of coronal structure, the fracture strength did not differ among the post types evaluated. In the presence of remaining coronal structure, the fracture strength was higher in specimens with cast cores and posts.

Association between personality traits and quality of life in patients treated with conventional mandibular dentures or implant-supported overdentures.

Studies investigating the relationship between personality traits and quality of life related to the types of dental prostheses are scarce. The aim of the present study was to assess personality traits and their impact on quality of life for individuals treated with either conventional mandibular dentures (CMD) or implant-supported overdentures. Fifty patients with CMD and 50 patients with implant-supported mandibular overdentures (IMOD) were recruited. Individuals were examined; clinical and demographic data of interest were collected. All participants agreed to answer two questionnaires: the Oral Health Impact Profile (OHIP-14), which assessed quality of life related to oral health, and the Neuroticism Extraversion Openness Five-Factors Inventory (NEO FFI-R), which evaluated five personality domains. The influence of variables of interest on oral health-related quality of life was tested by univariate analysis and multiple linear regression. Patients with CMD reported higher levels of impact on quality of life (OHIP-14=10·30 ± 5·88) when compared to patients with IMOD (OHIP-14=6·52 ± 5·91; P=0·002). Multivariate predictive regression model for quality of life included neuroticism, conscientiousness and gender for the conventional mandibular denture group (P<0·05; R(2)=36·59%), whereas neuroticism, openness and schooling (P<0·05; R(2)=21·09%) were included in the implant-supported mandibular denture group model. Patients with IMOD had less impact on quality of life than patients with CMD. Personality traits, mainly neuroticism, had a significant influence on oral health-related quality of life linked to a chosen modality of prosthetic therapy.

Tooth displacement due to occlusal contacts: a three-dimensional finite element study.

The use of the Finite Element Method (FE) is an appropriate way to study occlusal forces and tooth movement. The purpose of this study was to evaluate the effects of different occlusal contact patterns on tooth displacement in an adult dentition using a three-dimensional FE model of a human maxilla and mandible. Initially, images of a computerized tomography scan were redrawn in a computer program (CATIA) followed by the FE mesh construction. The MSC/Patran software was used to develop the FE mesh comprising 520,445 elements and 106,633 nodes. The MSC/Nastran program was utilized as pre and post-processor for all mathematical calculations necessary to evaluate dental and mandibular biomechanics. Four occlusal patterns were tested: FEM 1 - standard occlusal contacts; FEM 2 - removal of mesial marginal and mesial tripoidism contacts; FEM 3 - removal of distal marginal and distal tripoidism contacts; FEM 4 - similar to FEM 3 with added contacts between upper and lower incisors. Small changes in the standard distribution of occlusal contacts resulted in an imbalance of occlusal forces and changes in dental positioning. All simulations tested showed mesial displacement of posterior teeth. The most significant changes were registered in the model presenting unstable occlusal contacts when the anterior teeth were in occlusion (FEM 4). These findings may explain mandibular incisors crowding and maxillary incisors flaring as a result of small variations in dental contacts.

Peripheral ameloblastoma.

A case of peripheral ameloblastoma in a 57-years-old woman is presented, along with a discussion of the clinical and histological characteristics of the lesion. After clinical and radiographic examinations, and with a differential diagnosis of pyogenic granuloma, an excisional biopsy was performed and the material collected was sent for histological examination. On the basis of the histopathological diagnosis, a second operation was performed with a wide safety margin, including bone tissue, which did not show any involvement with the odontogenic neoplasm.

Incontinentia pigmenti (Bloch-Sulzberger syndrome): a case report.

A syndrome--incontinentia pigmenti--of probable genetic etiology, is discussed and a new case report presented. The syndrome presents systemic and dental manifestations, which are separate although similar to those found in other disease entities, i.e., congenital syphilis, hereditary ectodermal dysplasia.