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PubMed1999

Effect of aluminium oxide sandblasting on cast commercially pure titanium surfaces.

Studies on the titanium porcelain interface have shown the presence of alumina, attributed mainly to the sandblasting procedure. In this study, an investigation of the effect of the sandblasting procedure on the microstructure and roughness of a cast commercially pure titanium surface was undertaken using three different particle size alumina powders. The analysis showed that in all cases alumina particles are embedded into the surface layer of titanium. The use of a large particle size alumina seems to be advantageous in reducing the weight of alumina remaining on the titanium surface and while increasing the surface roughness, thus promoting mechanical interlocking with porcelain.

Aluminum Oxide↗
PubMed2000

Micro-morphometric assessment of titanium plasma-sprayed coating removal using burs for the treatment of peri-implant disease.

This study evaluated, in vitro, the effectiveness of diamond and carbide burs, and bur sequences to remove the plasma-sprayed titanium coating from IMZ fixture surfaces. Fifteen polishing procedures were tested. They included the use of 12, 16, 30 bladed carbide burs or bevered carbide burs and 30, 15, 8 microns mean-particles-size diamond burs. The treated surfaces were evaluated with profilometer and SEM. Worn burs and titanium debris produced by the grinding were observed with SEM. All procedures produce smoother surfaces than baseline plasma-sprayed surfaces for both Ra and Rz(DIN) parameters (P < 0.001). A roughening effect of the 8 microns mean-grit diamond bur and 30 bladed burs were noted. The single carbide burs produce polished surfaces affected by waviness. Waviness was minimized by sequence or diamond bur use. The carbide bur blades were variously damaged after their use. In contrast, the grit of diamond burs was observed to be clogged by titanium debris whose amount seemed to be inversely related to the diamond mean particle size. Debris produced by diamond burs was granular whereas that produced by carbide bladed burs showed needle or flake morphology. In conclusion, the most effective titanium plasma sprayed removal were obtained by 30 microns and 15 microns mean-particle-size diamond burs, i.e. 30 microns plus 15 microns diamond burs and carbide 12 plus 16 bladed burs used in sequence.

Analysis of Variance↗
PubMedDate not supplied

A comparison of laser-welded titanium and conventional cast frameworks supported by implants in the partially edentulous jaw: a 3-year prospective multicenter study.

PURPOSE: The purpose of this prospective multicenter study was to evaluate and compare the clinical performance of laser-welded titanium fixed partial implant-supported prostheses with conventional cast frameworks. MATERIALS AND METHODS: Forty-two partially edentulous patients were provided with Brånemark system implants and arranged into 2 groups. Group A was provided with a conventional cast framework with porcelain veneers in one side of the jaw and a laser-welded titanium framework with low-fusing porcelain on the other side. The patients in group B had an old implant prosthesis replaced by a titanium framework prosthesis. The patients were followed for 3 years after prosthesis placement. Clinical and radiographic data were collected and analyzed. RESULTS: Only one implant was lost, and all prostheses were still in function after 3 years. The 2 framework designs showed similar clinical performance with few clinical complications. Only one abutment screw (1%) and 9 porcelain tooth units (5%) fractured. Four prostheses experienced loose gold screws (6%). In group A, marginal bone loss was similar for both designs of prostheses, with a mean of 1.0 mm and 0.3 mm in the maxilla and mandible, respectively. No bone loss was observed on average in group B. No significant relationship (P > 0.05) was observed between marginal bone loss and placement of prosthesis margin or prosthesis design. CONCLUSION: The use of laser-welded titanium frameworks seems to present similar clinical performance to conventional cast frameworks in partial implant situations after 3 years.

Adolescent↗
PubMed2000

[Titanium joints welded with laser and infrared techniques: comparative analysis of its microstructure].

BACKGROUND: Aim of the study is to compare microstructure of Titanium joints soldered with Laser and Infrared methods by performing SEM analysis, metallography and microhardness evaluation. METHODS: Wax specimens were separated in the middle area corresponding to the joint region, machined and then soldered. 40 Titanium samples were fused and divided in 2 groups of 20 samples each. First group was soldered by laser welding, second one by infrared brazing. SEM analysis and standard metallography were carried out at joined areas and unsoldered surfaces. Microhardness test was performed on longitudinally sectioned samples with 150 g load for 15 second up to 7 mm distance from the joined area. RESULTS: SEM photomicrographs revealed for group 1 a homogeneous metal-joint interface, without microporosities; for group 2 exhibited a distinct demarcation of metal joint interface. Metallography evaluation showed for laser joined samples only the presence of Titanium; infrared joined samples showed in soldered regions also Ni and Cu. Microhardness values detected at the joined surfaces seem to be higher for both considered groups. CONCLUSIONS: Laser joining method with exclusive presence of Titanium seems to be ideal for monometallism; both techniques exhibited microstructural changes in the heated surface layer.

Hardness Tests↗
PubMed2000

Characterizations of three surface-modified titanium oxide films.

OBJECTIVE: To seek a new method of titanium passive treatment by combined anodic oxidation and thermal air treatment, which could increase the corrosion resistance and biocompatibility of pure titanium. MATERIAL AND METHODS: Characteristics of Titanium sheets with natural oxide film (NOF), anodic oxide film (AOF), or heated anodic oxide film (HAOF) were compared and tested by x-ray diffractrometer, electrochemical corrosive method, and contact angle device. RESULTS: HAOF had excellent corrosion resistance and greater crystallinity, indicating the crystal structure had changed. AOF had better hydrophily. CONCLUSION: This in vitro study showed that thermal air treatment, after anodic oxidation, was a reliable method for creating a passive, protective film on the titanium surface, which could greatly enhance the corrosion-resistance and crystallinity.

Air↗
PubMed2001

Titanium-porcelain system. Part IV: some mechanistic considerations on porcelain bond strengths.

The titanium-porcelain system can be considered as a double-layered structure, comprising of at least titanium substrate and porcelain body including bonding agent. Stress distribution pattern of such a double-layered structure is not necessarily same as that of a single beam under the 3-point bending testing mode. Previously tested porcelain-fired commercially pure titanium samples (n = 285) were re-evaluated. All obtained data on bond strengths and bond toughness (energy-to-break) were re-grouped in terms of c/t ratio, where c is the distance from the maximum compressive side of the beam to the calculated neutral axis and t is the thickness of titanium substrate plate thickness. It was found that (1) when the double-layered structure falls in the c < t situation, both bond strength and bond toughness are in a lower zone, which is slightly lower than the cohesive tensile strength of the porcelain, (2) when the c > t situation (with relatively thick porcelain application) is established, both bond strength and toughness are in higher zone than the porcelain itself, and (3) there is a transition zone between the above.

Dental Bonding↗
PubMed1999

[High voltage transmission electron microscope and X-ray double-crystal diffractometer observation of pure titanium implant-bone interface].

OBJECTIVE: To examine the integration of pure titanium implant and bone tissue. METHODS: Using low temperature dualion mill technique, the interface of titanium implant and bone was examined with high voltage transmission electron microscope and X-ray double crystal diffractometer. RESULTS: It was shown that calium globules of various electron density or sheets of calcified osseous tissue blended with titanium at the interface. The bone had grown in two directions. CONCLUSION: The integration of pure titanium implant and bone tissue is good, leaving no gap at their interface.

Animals↗
PubMed2001

Effect of calcitonin on bone formation around titanium implant. A histometric study in rabbits.

Bone healing around titanium implants has already been evaluated; however, the effect of drugs such as calcitonin during the period of bone maturation around titanium implants has not yet been investigated. The purpose of this study was to evaluate the effects of calcitonin administration on the late period of bone healing following titanium implant insertion. Twenty-seven adult New Zealand rabbits received one implant in each femur. Thirteen animals were randomly selected as the test group (2 IU/kg--calcitonin) and fourteen animals served as control (saline). The animals were sacrificed 6, 8, 12 and 18 weeks after surgery. Endosteal/periosteal bone length (EB/PB), endosteal/periosteal bone area (EBA/PBA) and total cortical length (TCL) around the implants were analyzed. After 6, 8, 12 and 18 weeks, a positive time effect was strongly observed (P < 0.05). Considering the treatment factor, there was a positive effect of calcitonin on EBA and EB variables at 12 weeks and TCL at 18 weeks. In conclusion, the administration of salmon calcitonin to healthy animals may improve bone mass at the later stages of bone healing following titanium implant insertion.

Analysis of Variance↗
PubMed2001

Correction of severe enophthalmos with titanium mesh.

The aim of this study was to analyse the types of facial fractures that caused severe enophthalmos and the outcome after repair of the medial wall and the floor of the orbit with titanium mesh. Eighteen cases with severe enophthalmos were repaired with titanium mesh in Siriraj Hospital between January 1992 and December 1999. We recorded the types of facial fractures of the patients, the results after operations and the complications. All cases were followed-up for at least 6 months. Le Fort fracture was the most common cause of severe enophthalmos from orbital fracture. The results after operations were satisfactory in 17 cases. Only one case still had enophthalmos after the first correction with titanium mesh and needed further repair with bone graft. Few complications happened post-operatively. They were 4 cases of chemosis and 4 cases of temporary diplopia. All subsided spontaneously. The author concludes that titanium mesh can be used to repair the medial wall and the floor of the orbit with good results.

Adolescent↗
PubMed1999

Orbital floor repair with titanium mesh screen.

BACKGROUND AND OBJECTIVES: Surgical repair of the acutely fractured orbit strives to restore appearance, preserve ocular and orbital function, and avoid enophthalmos or hypoglobus. Repair is achieved with autologous bone graft, synthetic substitutes, or both. The purpose of this article is to present an alternative procedure--use of implants, cut from a titanium mesh screen, without bone graft. METHOD AND MATERIALS: A total of 51 orbital floor fractures in 43 patients were repaired with titanium mesh screen implants. In three patients with bilateral orbital floor fractures repaired with titanium mesh, intraoperative symmetry was improved with bone graft added to the mesh on one side. RESULTS AND/OR CONCLUSIONS: Follow-up was available for 42 orbits in 35 patients and averaged 9 months. The transconjunctival approach with lateral canthotomy yielded better results than the subciliary approach, which often caused transient scleral show or ectropion. One patient underwent surgery for ectropion following a subciliary approach, and one patient developed a 4-mm enophthalmos. Routine bone grafting is unnecessary, even in large floor defects. Titanium mesh implants are a simple and reliable option for orbital floor repair.

Bone Transplantation↗
PubMed2002

A new porous titanium-nickel alloy: Part 1. Cytotoxicity and genotoxicity evaluation.

Porous titanium-nickel (PTN) alloys represent new biomaterials for long-term implantation. Their porosity properties might confer them the capacity to trigger fluid capillarity, tissue ingrowth, as well as good tissue-implant apposition and fixation. Before PTN materials are used as long-term implants, their biocompatibility level must be assessed. In this study, porous titanium-nickel was therefore extracted in a saline semi-physiological solution and materials were evaluated for potential cytotoxicity and genotoxicity reactions. The cytocompatibility elution test was performed in order to determine PTN toxic potential at the in vitro cellular level: no reactivity was detected in cell layers exposed to PTN extracts or the negative controls. In parallel, the genocompatibility of porous titanium-nickel was evaluated using three different assays in order to assess potential damage at the DNA level: the test for chemical induction of chromosome aberrations, the Salmonella typhimurium and Escherichia coli reverse mutation assay, and the mouse micronucleus test. No significant increase in the number of chromosomal aberrations, bacterian revertant colonies, or micronuclei was observed in presence of PTN extracts when compared to negative control exposition. Based on the above results, porous titanium-nickel can be considered completely cytocompatible and genocompatible, and therefore represents a good candidate for long-term implantation.

Animals↗
PubMedDate not supplied

Implant-supported welded titanium frameworks in the edentulous maxilla: a 5-year prospective multicenter study.

PURPOSE: This study evaluated the 5-year clinical and radiographic performance of fixed implant-supported maxillary prostheses with either welded titanium or conventional cast-gold alloy frameworks. MATERIALS AND METHODS: Fifty-eight consecutive patients were provided with 349 osseointegrated Brånemark system implants in the edentulous maxilla at six different implant centers. Twenty-eight of the patients received, at random, prostheses with laser-welded titanium frameworks, and the remaining 30 patients had prostheses with conventional cast-gold alloy frameworks. Clinical and radiographic data were collected for 5 years after prosthesis placement. RESULTS: The titanium and cast-gold framework groups exhibited similar cumulative survival and success rates (CSR). The 5-year implant CSR from time of placement was 91.4% and 94.0%, respectively, and from prosthesis delivery the rate was 94.9% and 95.6%, respectively. The corresponding 5-year prosthesis CSRs were 96.4% and 93.3%. One patient from each group lost all the implants and turned to complete dentures within the first year of function. Another patient with a cast-gold framework had the prosthesis replaced after 4 years, basically because of problems with the veneering material. No fractures of implant components were observed during the follow-up period. Bone loss was on average 0.59 mm (SD 0.97 mm) during 5 years, with no statistical difference between the two groups. CONCLUSION: Welded titanium frameworks presented a similar favorable clinical performance as conventional cast-gold alloy frameworks in fixed implant-supported prostheses in the edentulous maxilla after 5 years in function. Implant failures were concentrated in only a few patients in each study group.

Adult↗
PubMed2000

[A study of polysaccharide-protein complex and glycosyls in the tissue surrounding titanium implant of rabbit].

OBJECTIVE: The absorption of the polysaccharide-protein complex to the implant surface may be the first reaction between the implant and the surrounding tissue. So we observed the distribution and the relative amount of the polysaccharide-protein complex and glycosyls in order to find out the possible functions and changing rules of these substances. METHODS: 12 rabbits were selected according to the age, sex, weight, and health conditions. Bilateral mandibular premolar teeth of rabbits were extracted under abdomen anesthesia (2% glutababituratic acid), then 12 titanium implants were placed into the teeth extraction holes of one side and left the other side to be the control one. All of the implants were required to be placed 2 mm below the alveolar crest, and tissue closure was achieved with mattress and interrupted single sutures. Antibiotic injections were given to the rabbits in the following 3 days. The animals were sacrificed at the end of 1 week, 4 weeks and 24 weeks. Tissue blocks (4 mm x 4 mm x 4 mm) containing the titanium implants and the control ones were removed, then fixed with 10% formaldehyde for 2 weeks, and decalcified with 10% EDTA (pH7.0) for 8 weeks. Carefully removed the titanium implants, the tissue blocks were embedded into the paraffin wax, then the sections were obtained and stained using following methods. 1. Alcian Blue Method: Alcian blue (pH 2.5) staining displayed the acidic proteoglycans; Alcian blue (pH 1.0) displayed the proteoglycans containing sulfonyl; Alcian blue/periodix acid-shiff staining demonstrated the acidic and neutral proteoglycans respectively. Alcian blue-MgCl2 with different ionic concentration identified the different kinds of proteoglycans. 2. Lectin Method: 5 kinds of lectins were used to locate 5 kinds of glycosyls. 2.5 micrograms/ml ConA located the glucose; 10 micrograms/ml PNA located the galactose; 10 micrograms/ml WGA located the N-acetylglucosamine; 25 micrograms/ml PHA-E located N-acetylgalactosamine, 10 micrograms/ml WPL loacted the fucose. RESULTS: High level of proteoglycans and glycosyls were observed in the peri-implant connective tissue during all phases of the experiment. It was also observed that polysaccharide-protein complex and glycosyls reached a high level in new bone matrix as well as osteoblasts. CONCLUSION: Polysaccharide-protein complex and glycosyls do play an important role in the implant-bone attachment, and titanium compatibility and may be closely related to the bone metabolic activity.

Animals↗
PubMed2000

[Histological study on the polyhydroxybutyric ester(PHB) membrane used for guided bone regeneration around titanium dental implants].

OBJECTIVE: To evaluate the effects of PHB membrane around dental titanium implants used in guided bone regeneration technique. METHODS: Endosseous cylindrical implants were placed in dogs' mandibles after extraction of all the mandibular premolars and the first molars immediately. Ideal implant placement sites were modified by creating standardized 3 mm x 5 mm facial dehiscent defects. The defects were covered with PHB membrane and titanium membrane respectively, then the membranes were fixed on the periosteum by sutures, and the remainder served as controls. Tissue closure was achieved with mattress and interrupted single sutures, and antibiotic injection was given to the dogs in the following 3 days. The dogs were divided into three groups according to the healing time of 1, 2 and 3 months, then the three groups of dogs were sacrificed. After that, tissue blocks containing the implants and the control ones were removed and studied by gross observation, X-ray radiograph and fluorescence microscope, and the surfaces of the membranes were observed by scanning electron microscope. The specimen used for light microscope study were fixed with 10% formaldehyde for 24 hours, and decalcified with 0.5 mol/L EDTA for 2 weeks. After the titanium implants were carefully removed, the tissue blocks were embedded into the paraffin wax, and the sections were obtained. RESULTS: The PHB membrane degraded slowly and partly 3 months after placement, and the biodegradable property of the PHB membrane deserved a longer period of study; The bone defects covered with PHB and titanium membrane were filled with much more new bone than that of the control group. CONCLUSION: PHB membrane can enhance bone formation and can be used for guided bone regeneration.

Animals↗
PubMed2003

[Microcosmic analysis of amino group implanted titanium].

OBJECTIVE: The purpose of this study was to determine the effects of amino group implantation on the surface structures of titanium. METHODS: The amino groups were implanted into the surfaces of titanium using 100 keV amino group ions at ambient temperature (25 degrees C) with the following three different doses: 5 x 10(17), 1 x 10(17) and 5 x 10(16) ions per cm2. The current density of the ion-beam was (10 microA/cm2. The modified surfaces were characterized using X-ray photoelectron spectroscopy (XPS) to determine the chemical components of the modified surfaces. A scanning electron microscope (SEM) was used to study the physical structure of the surfaces. RESULTS: The wide XPS profiles, the binding energy data and the SEM photos were obtained. The XPS showed that the modified surface contained Ti, O, C and N. The possible chemical states were speculated using Gauss matching analysis. There was no significant difference between the surfaces with and without implanted amino groups. CONCLUSION: The XPS data reveals that the structure of the modified surface layer of aminogroup-implanted titanium is TiN, comprising a complex structure of titanium and amino compound near the surface. The SEM Photos show that this technique has little effect on the surface structures of materials.

Amines↗
PubMed1992

Visualization and initial characterization of the titanium boundary of the bone-implant interface of osseointegrated implants.

A simple procedure has allowed consistent visualization of the titanium boundary of the bone-implant interface of osseointegrated titanium implants at the electron microscope level. This was accomplished by embedding the intact bone-implant specimen block with low-viscosity resin prior to removal of the device in preparation for sectioning. The titanium boundary consisted of either a thin, compact amorphous electron dense layer, a broad layer of dense amorphous granules, or both. This material was removed by decalcification in formic acid (prior to embedding) and did not diffract electrons (ie, was noncrystalline). Scanning-transmission electron microscopy-EDX analysis indicated the presence of titanium, calcium, and phosphorus in the electron dense material. Field emission scanning electron microscopy-EDX dot-mapping analysis confirmed the presence of these elements and mapped them to the same locations at the implant-interface boundary.

Animals↗
PubMed2003

[Reconstruction of segmental mandibular defect of canine using titanium-nickel distractor].

OBJECTIVE: To establish a continuous and automatic distraction osteogenesis technique in reconstruction of segmental mandibular defect by using embedded titanium-nickel alloy distractor with characteristics of shape-memory and super-elasticity. METHODS: Adult hybrid canines were used as the animal model. Segmental defects of 1-3 cm in the body of mandible were created by surgical osteotomy. Bi-focal distraction osteogenesis was applied using embedded titanium-nickel distractor designed by the authors. The canines were sacrificed 3 months after the operation and the mandibles were harvested to examine the results of bone regeneration. RESULTS: The histocompatibility of titanium-nickel distractors was good. Distraction osteogenesis was completed automatically and the defects were elementarily restored. Radiological and histological examination showed well bone regeneration in distraction area. CONCLUSIONS: Distraction osteogenesis using embedded self-loading titanium-nickel distractor could be a hopeful and useful technique. It might help to solve the problems of functional mandibular reconstruction in the near future.

Animals↗
PubMed2004

Mechanism of apatite formation on pure titanium treated with alkaline solution.

The mechanism of bone-like apatite formation on the surface of pure titanium pretreated with NaOH solution is still being investigated. The apatite formation may depend on the solution that is used. In the present study, several types of solutions such as simulated body fluid (SBF), calcium aqueous solution (CAS), and phosphate aqueous solution (PAS) were used to investigate bone-like apatite formation on alkali-treated titanium. In order to observe the effect of hydrolysis on the apatite formation, experiments of pretreated titanium immersed in distilled water before the immersion in SBF were also conducted. The results showed that the mechanism of apatite formation was the hydrolysis reaction of sodium titanate which induced the apatite formation. The pre-precipitation of either calcium or phosphate could prevent the apatite formation on the surface of alkaline treated titanium.

Adsorption↗