Alexandru A Iliescu

Current Options of Making Implant Supported Prosthetic Restorations to Mitigate the Impact of Occlusal Forces

The lack of a periodontium for a dental implant may lead to high stress concentration at the bone level when the implants are prosthetically loaded. The present paper discusses the current possibilities of implant supported prosthesis making in order to mitigate the impact of occlusal forces. The cement layer may serve as an absorber for the strain, but its role is reduced and poses the risk of excess cement retained in the peri-implant tissue. The use of resin materials for the implant supported prosthetic restorations veneering it has been suggested for many years, but their role it is important in the case of full-arch fixed implant-supported prosthesis with cantilever distal extensions and less in single implant restorations. Nowadays, new materials like fiber-reinforced composites and high-performance polymers as PEEK may be used for the framework of the implant supported prosthetic restorations, but also for the implant or the prosthetic abutment realization.

Bioceramics and Endodontics: Present and Expectations in Clinical Use

Currently bioceramics are preferentially used in various endodontic treatments such as pulp capping, pulp amputation, apexification, root-end fillings, perforation repair, and pulp regeneration. Additionally, bioceramics started to replace traditional materials still used in root canal fillings. The promising clinical results achieved during last 20 years by mineral trioxide aggregate (MTA) promoted in root canal treatments other MTA-like innovative endodontic materials, some of them produced by nanotechnology. Though the newcomers claim to have at least the same efficacy as MTA only rigorous long-term clinical studies might confirm the expectations. Probably the most spectacular effect of using bioceramics in endodontics is mirrored in regenerative treatments. However, are still required proper treatment protocols able to optimize the signaling environment of bioactive molecules for achieving the most efficient pulp regeneration. Pivotal is also the balance between clinical and histological outcomes. As compared to conventional materials used in endodontic treatments bioceramic cements are not only biocompatible but also bioactive as they proved to be involved in controlling the tissue healing and pulp regeneration. MTA or MTA-like cements are already the material of choice in regenerative endodontics, conservative vital pulp therapy and periradicular surgery due to their clinical success rate that spectacularly upraised in recent years. Based on in progress technology of fabrication it is expected that the newcomers belonging to bioceramic cements will overcome some potential clinical and histological downsides. MTA-based endodontic sealers are also promising promoters of improved interfacial bond between the filling material and the dentinal walls of root canal as a guarantee against microinfiltration.

Thermal Changes of Bone Induced during Drilling for Dental Implants Placement: An In Vitro Study

Bone Heating during Osteotomy for Dental Implant Placement is a High Risk Factor of Osteonecrosis. the Aim of this Study was to Investigate in Vitro the Temperature Changes Induced in Bone by Different Burs with External Cooling during the Surgical Step of Osteotomy. it was Used the Digital Infrared Camera FLIR SC640 (Flir Systems) that Allowed a Real-Time Infrared Thermographic Analysis of Thermal Images, Recorded 0.50 m Away from Osteotomy Site. there were Prepared 10 Osteotomy Sites with each MIS System Burs of Progressive Diameter (2 Mm ø, 2.8 Mm ø, and 3.2 Mm ø), at 2000 Rpm, on 30 Samples of Bovine Femoral Bone. the Thermographic Analysis Showed that the Mean Temperature Generated in Bone by Performing the Osteotomy was 46,5oC ± 0,48 for 2 Mm ø Bur, 59,5oC ± 1,62 for 2.8 Mm ø Bur, and 51,4oC ± 0,51 for 3.2 Mm ø Bur. Surprisingly the Maximal Temperatures were Recorded with Intermediatte 2.82 Mm ø Bur. the Infrared Thermography Proved to Be a High Accurate, Fast, and Efficient Non-Invasive Method of Bone Temperature Measurement Generated during Drilling for Placement of Dental Implants. while Drilling the Bone in a Progressive Sequence of Bur Diameters, the Temperature Raise is Non-Uniform because the Quantity of Removed Bone is Changing from One Bur to the other, and the Mechanical Friction of Following Burs in the Series is Reduced as Compared to the Pilot Bur.

Tissue Reaction to Subcutaneous Implantation of SuperEBA (Reinforced Zinc Oxide Cement) Used as Root-End Filling Material: A Histological Study in Rats

The retrograde filling is a critical step to a successful outcome of the endodontic surgery. Despite the progress in the technology of novel root-end filling materials, zinc oxide-eugenol cement superEBA is still preserving its clinical value on long-term basis. The study aimed to reconsider the tissue response to the initial irritating effect of this material. Silicon tubes filled with superEBA were subcutaneously implanted for 120 days in white Wistar rats which were afterwards sacrificed. The connective tissue surrounding the superEBA implants revealed fibroblast proliferation and a definite reparatory process without inflammatory reaction. A non-specific tissue healing in progress around the implants, without calcifications, necrosis, and apoptosis was also described after 4 months. SuperEBA proved on animal model that its cytotoxicity is reducing gradually in time until no adverse reaction is observed. The reduced content in eugenol compared to other surgical zinc oxide cements and the benefic effect of o-ethoxybenzoic acid are the support to reconsider SuperEBA as a biocompatible retrograde filling material.