Manufacture Of Dental Implants Research Articles

Study of the adherence capacity of microbial biofilms on titanium versus zirconium dioxide (Zirconia) surfaces

Introduction. An important role in the appearance of acute or chronic infections is played by bacterial biofilms that contain several bacterial species and that develop preferentially on inert surfaces, dead tissues and medical devices. Purpose. In this material we tried to make an interesting study, regarding the adhesion capacity of microbial biofilms characteristic of the oral cavity of human subjects on the surface of materials used for industrial scale manufacturing of dental implants: titanium and zirconium dioxide (Zirconia). Material and methods. For this study were used plates of Ti4 and zirconia, on which adhesion of different bacterial strains belonging to the species Enterobacter cloacae, Klebsiella oxytoca and Klebsiella pneumonia were tested. Results and discussions. A rather high microbial load was observed on both types of materials for all types of bacterial strains studied. For certain types of strains, a lower colonization was noted in the case of zirconium dioxide compared to Ti4 surfaces. Conclusions. Although Zirconia has been reported to have a lower susceptibility to bacterial adhesion, our study contradicts this aspect specified in the literature. Both titanium and zirconium dioxide are promptly colonized by existing bacteria on the teeth left in the oral cavity

Application of Plasma Electrolytic Oxidation Coating on Powder Metallurgy Ti-6Al-4V for Dental Implants

Ti-6Al-4V alloy obtained by powder metallurgy (PM) is a good candidate biomaterial in the manufacture of dental implants but its inherent porosity makes it have worse corrosion behavior than conventionally obtained alloys. In order to improve the corrosion and biological properties, surface modification technologies could be used. The plasma electrolytic oxidation (PEO) process is a novelty process successfully used in case of conventional titanium alloys. The present work investigates the effect of PEO treatment on PM Ti-6Al-4V alloy using two electrolytes. Both coatings show good adherence and improved corrosion behavior in artificial saliva, the PEO coatings delivers a steady growth of corrosion resistance from day one until 90 days immersion. Highest corrosion resistance was shown in case of Ca/P enrichment PEO coatings. The cytocompatibility tests indicated these coatings seem to be appropriate to improve the bone osseointegration with proper porosity index.

In-vivo study of ultrafine-grained CP-Ti dental implants surface modified by SLActive with excellent wettability

This study investigates the simultaneous effect of substrate nanostructuring by severe plastic deformation and surface modification by SLActive on surface characteristics of CP-Ti grade 2 and evaluates the biocompatibility of it for use as implant material by in-vivo test. SLActive surface modification method is a modified SLA process that includes sandblasting, acid-etching, and cleaning by N2 in a vacuum chamber. To this end, the structure CP-Ti grade 2 was refined by applying the equal channel angular pressing (ECAP) method. Surface morphology, roughness, and wettability of coarse-grained (CG) and ultrafine-grained (UFG) CP-Ti and Ti-6Al-4V were determined after SLActive. It was seen that after surface modification of the samples by SLActive, the excellent wettability with a drop contact angle of about 0° was achieved for SLActived specimens. For the in-vivo test, the implants of each three groups were embedded in the femur of white New Zealand rabbits. In order to assess the osseointegration of implants, histological analysis, and pull-out tests were conducted. Results showed suitable osseointegration between implant and bone for every three groups, but the value of removal torque was higher for UFG-Ti. As is realized UFG-Ti sample surface modified by SLActive could be a suitable choice among the candidates to be used as a material in the manufacturing of dental implants.

On the Future Design of Bio-Inspired Polyetheretherketone Dental Implants.

Polyetheretherketone (PEEK) is a promising implant material because of its excellent mechanical characteristics. Although this polymer is a standard material in spinal applications, PEEK is not in use in the manufacturing of dental implants, where titanium is still the most-used material. This may be caused by its relative bio-inertness. By the use of various surface modification techniques, efforts have been made to enhance its osseointegrative characteristics to enable the polymer to be used in dentistry. In this feature paper, the state-of-the-art for dental implants is given and different surface modification techniques of PEEK are discussed. The focus will lie on a covalently attached surface layer mimicking natural bone. The usage of such covalently anchored biomimetic composite materials combines many advantageous properties: A biocompatible organic matrix and a mineral component provide the cells with a surrounding close to natural bone. Bone-related cells may not recognize the implant as a foreign body and therefore, may heal and integrate faster and more firmly. Because neither metal-based nor ceramics are ideal material candidates for a dental implant, the combination of PEEK and a covalently anchored mineralized biopolymer layer may be the start of the desired evolution in dental surgery.

Surface roughness of biomaterials and process parameters of titanium dioxide gritblasting for productivity enhancement

Titanium is used in dental implants because of its properties as a biomaterial. Surface roughness is very important and fundamental for obtaining required results of biocompatibility. Dental implants with moderately rough surfaces are commonly used in the treatment of edentulous patients. Aiming for improvements in productivity, experiments were conducted in a dental implant industry to evaluate the influence of machining parameters on the surface of dental implants. Samples of different diameters were machined with specific parameters and their roughnesses were measured, before and after blasting, with and without asepsis chemical attack. The results indicate a random increase in roughness according to increase of feed parameter, evidencing that there is no relation between roughness and machining feed after gritblasting. Samples exposed to gritblasting that did not undergo chemical asepsis showed a decrease in roughness, compared to roughness of blasted samples and submitted to asepsis process. However, this trend remained constant leading to the conclusion that titanium-blasting process makes the surface roughness uniform, independently of first roughness variation. No relationship was observed between the variation of feed and the variation of roughness. Thus, in terms of productivity, cutting feed was increased with no harm to the biocompatibility. After more than twenty years of its first use in the industry, this study proves the possibility of changes in the process parameters of titanium dioxide gritblasting to increase productivity in the manufacture of dental implants.

BENEFITS OF LASERTHERAPY IN BONE SURGERY AND IMPLANTODONTICS

It is essential to perform the dental implant if we observe the quantity and quality of the bone remaining in the patient, because the main determinant factors in the prognosis of successful implants are: the professional’s experience and the amount of bone available in the patient. Bone cavities, under normal conditions and provided that the etiological agent has been eliminated, are repaired through a natural biological process. The extent and speed of repair, however, depend on the anatomical location; etiological agent; the size of the lesion; and the biological characteristics of each individual. Therefore, a long period of time may be necessary for the complexion of the repair process, thus exposing the patient to unnecessary risk and discomfort. Edentulism is one of the most frequent problems that affects the elderly population and results in pathophysiological changes of the maxillary edges and the modification of its structure. The advent of dental implants revolutionized the direction of dentistry in the last two decades of the 20th century when its clinical indication was universalized, thus covering oral rehabilitation in individuals totally or partially toothless. Research has shown a good acceptance of most of the materials used in the manufacture of dental implants, which should be biocompatible with tissues since the success of the procedure depends on the implant-tissue interaction. The indications of dental implants require careful planning and careful analysis of several factors, among which stand out: the evaluation of the quantity and quality of bone tissue in the implant receiving area and anatomical accidents that limit the application of techniques in conventional implantodontia.

Behaviour of a biocompatible titanium alloy during orthogonal micro-cutting employing green machining techniques

The sustainability of a process is the objective of modern industries aiming to reduce waste in production, since consumers require high quality and efficiency with fair price. Thus, a good understanding of the process should be its starting point. The manufacture of dental implants is an example in which waste reduction is important for the reduction of prices due to the demand for great quality and accuracy. This study observed the behaviour of sustainable micro-cutting applied to the Ti-6Al-7Nb titanium alloy, considering the ploughing effect on minimum quantity lubrication (MQL) and high-speed machining (HSM) conditions. When compared with dry condition and low-speed cutting in orthogonal micro-cutting, the use of HSM in dry cutting was more efficient than using MQL. The dry condition presented lower surface roughness, whilst the cooled/lubricated condition presented lower burr formation.

Identification of Surface Characteristics Created by Miniature Machining of Dental Implants Made of Titanium Based Materials

One of the most important characteristic of dental implant made of biomaterials is ability to create correct interaction between implant and bone tissue. Since most of the implant surface is in direct contact with bone tissue, shape and integrity of said surface has great influence on successful osseointegration. The most implemented material in manufacturing of dental implants is titanium of different grades of pureness. Among other characteristics that predetermine titanium as ideal biomaterial, titanium shows high mechanical strength making precise miniature machining increasingly difficult. The article deals with resulting quality, integrity and characteristics of dental implants surface after machining.

Non-Destructive Analysis of Basic Surface Characteristics of Titanium Dental Implants Made by Miniature Machining

Abstract One of the most best-known characteristic and important requirement of dental implant is made of biomaterials ability to create correct interaction between implant and human body. The most implemented material in manufacturing of dental implants is titanium of different grades of pureness. Since most of the implant surface is in direct contact with bone tissue, shape and integrity of said surface has great influence on the successful osseointegration. Among other characteristics of titanium that predetermine ideal biomaterial, it shows a high mechanical strength making precise machining miniature Increasingly difficult. The article is focused on evaluation of the resulting quality, integrity and characteristics of dental implants surface after machining.

Surface modification of Ti implants by plasma oxidation in hollow cathode discharge

As a result of superior biocompatibility and mechanical adequacy, titanium has been widely used in the manufacture of dental implants. On the downside, relatively long periods are normally required to fully integration of the bone into the implant. Surface modification techniques have the potential to shorten the osseointegration time of implants significantly contributing to patient comfort. In this work, plasma discharge in oxidizing atmospheres was used to modify the surface of Ti implants by the production of rough surfaces that consists of a mixture of Ti-oxides. The results showed that considerable improvement on surface roughness and mechanical stability of the oxidized layers could be achieved by confining the effect of the plasma discharge by shielding the cathodic region of the reactor. Processing parameters including temperature, time and pressure were optimized and applied to commercially available Ti implants. Improved wetting was obtained, which is potentially associated to shorter osseointegration periods.