Masticatory tensile developed in upper anterior teeth with chronic apical periodontitis. A finite-element analysis study

Vol. 54 No. 3 Suppl., 2013
This supplement was not sponsored by Outside Organizations.

ROMANIAN JOURNAL of MORPHOLOGY and EMBRYOLOGY

C. M. Petcu, D. Nitoi, Veronica Mercut, Mihaela Jana Tuculina, A. A. Iliescu, Cristiana Ileana Croitoru, Oana Andreea Diaconu, Mihaela Georgiana Iliescu, Lelia Mihaela Gheorghita, A. Iliescu

Commonly is accepted that a non-vital tooth has a higher risk of root fracture but there is a relatively little knowledge about the specific biomechanical behavior of non-vital frontal teeth with chronic apical periodontitis. The aim of our study was to evaluate the deformation and tensile generated in these teeth while vertically loading them because it is crucial to assess the moment when the absorbed occlusal forces exceed the elasticity of root dentine. Using the method of finite-element analysis, we highlighted the distribution patterns of the compressive and tension tensile, as well as their concentration areas. The vertical forces of 100 N generate deformations of no clinical risk in teeth with chronic apical periodontitis. The tensile developed in these teeth are higher than those in the vital teeth are but do not exceed the value of the elastic modulus of the radicular dentin. By increasing the force to 300 N occur elastic deformations, which cannot be neglected anymore. Even so, the 300 N forces do not generate deformations of the alveolar bone. The highest tensile at loading with 300 N was generated in vertical direction but in the cervical area of the tooth also developed tensile in lingual and mesiodistal direction that must be taken into consideration because they are near the risk limit of the elasticity modulus. The crack lines or fractures can appear both in case of excessive or even usual but accumulative occlusal forces that gradually alter the mechanical resistance of the tooth.

Corresponding author: Cristian Marian Petcu, Junior Assistant, DDS; e-mail: petrus_dorel.petcu@yahoo.com

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ROMANIAN JOURNAL of MORPHOLOGY and EMBRYOLOGY

H. Rotaru, G. Armencea, Diana Spirchez, C. Berce, Teodora Marcu, D. Leordean, Seong-Gon Kim, Sang-Woon Lee, C. Dinu, G. Baciut, Mihaela Baciut

The objectives of this study were to test the biocompatibility and to evaluate the osseointegration of Titanium-Aluminum-Niobium (Ti6Al7Nb) alloy used in the manufacturing of personalized implants with selective laser melting (SLM) technology and to compare the growth viability of osteoblastic-like cells on different Ti6Al7Nb alloy samples (plain, coated with hydroxyapatite or SiO2-TiO2) implanted into the cranial bone of Wistar rats. In terms of biocompatibility, the cone-beam computer-tomography head scans taken at the moment of sacrifice of each group (one, two and three months) showed no implant displacement, no osteolysis and no liquid collection around the implants. At one month, around all types of implants new bone formation was noticed, although around the plain Ti6Al7Nb implant a large amount of powder debris was present. Still, no inflammatory reaction was seen. At two months, the distance between the implants and the calvarial bone margins diminished. A thin layer of fibrous tissue was noticed around the Ti6Al7Nb implant coated with hydroxyapatite but no bone contact was achieved. In the group sacrificed at three months there was still no bone contact, but noticeable were the SiO2-TiO2. In the group sacrificed at three months SiO2-TiO2 particles detached from the implant and completely integrated in the tissue were noticeable. All results suggested that the Ti6Al7Nb alloy with or without infiltration is well biologically tolerated.

Corresponding author: Grigore Baciut, Professor, DMD, MD, PhD; e-mail: mbaciut@yahoo.com, gbaciut@umfcluj.ro

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