The influence of 1α.25-dihydroxyvitamin D3 coating on implant osseointegration in the rabbit tibia

Objectives: This study aims to evaluate bone response to an implant surface modified by 1α,25-dihydroxyvitamin D3 [1.25-(OH)2D3] in vivo and the potential link between 1.25-(OH) 2D3 surface concentration and bone response. Material and Methods: Twenty-eight implants were divided into 4 groups (1 uncoated control, 3 groups coated with 1.25-(OH)2D3 in concentrations of 10-8, 10-7 and 10-6 M respectively), placed in the rabbit tibia for 6 weeks. Topographical analyses were carried out on coated and uncoated discs using interferometer and atomic-force-microscope (AFM). Twenty-eight implants were histologically observed (bone-to-implant-contact [BIC] and new-bone-area [NBA]). Results: The results showed that the 1.25-(OH)2D3 coated implants presented a tendency to osseointegrate better than the non-coated surfaces, the differences were not significant (P > 0.05). Conclusions: The effect of 1.25-(OH)2D3 coating to implants suggested possible dose dependent effects, however no statistical differences could be found. It is thought that the base substrate topography (turned) could not sustain sufficient amount of 1.25-(OH)2D3 enough to present significant biologic responses. Thus, development a base substrate that can sustain 1.25-(OH)2D3 for a long period is necessary in future studies

Physicochemical and Antibacterial Characterisation of a Novel Fluorapatite Coating

Peri-implantitis remains the major impediment to the long-term use of dental implants. With increasing concern over growing antibiotic resistance there is considerable interest in the preparation of antimicrobial dental implant coatings that also induce osseointegration. One such potential coating material is fluorapatite (FA). The aim of this study was to relate the antibacterial effectiveness of FA coatings against pathogens implicated in peri-implantitis to the physicochemical properties of the coating. Ordered and disordered FA coatings were produced on the under and upper surface of stainless steel (SS) discs respectively, using a hydrothermal method. Surface charge, surface roughness, wettability and fluoride release were measured for each coating. Surface chemistry was assessed by X-ray photoelectron spectroscopy and FA crystallinity by X-ray diffraction. Antibacterial activity against periodontopathogens was assessed in vitro using viable counts, confocal and scanning electron (SEM) microscopies. SEM showed that the hydrothermal method produced FA coatings predominately aligned perpendicular to the SS substrate or disordered FA coatings consisting of randomly aligned rod-like crystals. Both FA coatings significantly reduced the growth of all the examined bacterial strains in comparison to the control. The FA coatings, and especially the disordered ones, presented significantly lower charge, higher roughness and area when compared to the control, enhancing bacteria–material interactions and therefore bacterial deactivation by fluoride ions. The ordered FA layer reduced not only bacterial viability but adhesion too. Ordered FA crystals produced as a potential novel implant coating showed significant antibacterial activity against bacteria implicated in peri-implantitis which could be explained by a detailed understanding of their physicochemical properties

Epidemiology of pneumoconiosis in coalminers of Nord-Pas-de-Calais in France

This is a longitudinal study of 3 167 active or retired pneumoconiotic coalminers from Nord - Pas de Calais collieries (HBNPC) recognised through medico-legal decision over three defined periods: 1942-61, 1952-81 and 1982-87

Trueness of CAD/CAM digitization with a desktop scanner – an in vitro study

Desktop scanners are devices for digitization of conventional impressions or gypsum casts by indirect Computer-Aided Design/Computer-Assisted Manufacturing (CAD/CAM) in dentistry. The purpose of this in vitro study was: 1, to investigate whether virtual models produced by the extraoral scanner have the same trueness as sectioned casts; and 2, to assess if digitization with an extraoral scanner influences the surface information

Oral Implantology: Myths Exposed in Recent Research.

Item does not contain fulltextToday, a variety of surgical and prosthetic protocols, implant designs, and prosthetic devices are used for implant dentistry, employing many different dental technologies. With a plethora of options available, choosing an implant system has become highly challenging for practitioners. Having an understanding of the role of different implant design properties may help clinicians make informed decisions. This article provides an overview of factors affecting osseointegration and preservation of bone and discusses the importance of surgical and prosthetic treatments that respect the biologic width and avoid interventions, such as cementation, that may disturb the surrounding soft and hard tissues.1 september 201

Immediate Placement of Ultrawide-Diameter Implants in Molar Sockets: Description of a Recommended Technique

Item does not contain fulltextImmediate implant placement is performed less frequently in molar extraction sockets than in single root sockets. This is mainly due to the tripodal anatomical configuration of molar roots, which is perceived as complex and therefore unsuitable. The mechanical burden of molar sites, combined with much larger socket dimensions, make it amenable to the use of ultrawide-diameter dental implants. This article describes a practical, sequenced technique that can be used predictably for immediate implant placement in maxillary and mandibular first molar sockets, using a dry skull model for clarification. This detailed description is based on the experience of more than 580 clinical cases over a 10-year period