Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Titanium”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,351 records · Page 75Linked to original sources
PubMed2006

Anatomical 3-dimensional pre-bent titanium implant for orbital floor fractures.

PURPOSE: This cadaver study evaluates the use of pre-bent 3-dimensional titanium mesh implants for orbital floor and medial wall reconstruction. DESIGN: Nonrandomized comparative study. PARTICIPANTS: Eight human cadaveric heads (n = 16 orbits). METHODS: Transcutaneous incisions were used to expose both orbital floors in each cadaveric head. Unilateral orbital floor and medial wall fractures were generated in each specimen. The contralateral orbit remained uninjured. The fractures then were repaired with pre-bent titanium mesh fan plates molded from aluminum templates presenting different sizes. The templates were generated from topographical computed tomography (CT) data previously obtained from normal subjects. The accuracy of orbital reconstruction was evaluated with postoperative CT scans. MAIN OUTCOME MEASURES: The mean value of the distances between the implant and the bony orbit was evaluated. RESULTS: The mean distance between all 16 plates and their respective orbital floors/medial walls was 0.81+/-0.74 mm. Mean values were 0.68+/-0.63 mm for the unfractured side and 0.93+/-0.82 mm for the fractured side. No significant differences were found between orbits when evaluated for side of injury, gender, or size of defect. CONCLUSION: Pre-bent 3-dimensional titanium mesh implants provide accurate reconstruction of orbital floor and medial orbital wall fractures. The mean implant error was <1 mm for all orbits studied.

Adult↗
PubMed2004

Minimizing complications in the use of titanium condylar head reconstruction prostheses.

OBJECTIVE: The study goals were to evaluate the use of titanium condylar prostheses in the setting of tumor resection and to discuss the techniques used to minimize complications. STUDY DESIGN AND SETTING: We conducted a retrospective review of a case series in a tertiary care hospital. Six patients underwent mandibulectomy, including the condyle, with primary reconstruction using titanium condylar prostheses. Charts were reviewed for operative technique, pathology, and complications. RESULTS: Pathology included squamous cell carcinoma, Ewing's sarcoma, embryonic rhabdomyosarcoma, giant cell granuloma, and adenocarcinoma. Three patients are alive without disease. Follow-up spanned 6.4 years with premorbid occlusion established in all cases, and there were no prosthesis extrusions or erosions. The condylar head was wrapped in preserved joint capsule or adjacent temporalis muscle/fascia and secured with permanent purse-string sutures; careful duplication of the length, and angulation of the native mandible from the angle to the superior extent of the condylar head. CONCLUSION: Titanium condylar prostheses are a viable choice in the setting of tumor resection and reconstruction, with appropriate technical precautions.

Adult↗
PubMed2004

Preliminary functional results of tympanoplasty with titanium prostheses.

OBJECTIVE: To assess the use of titanium prostheses in tympanoplasty for reconstruction of the sound pressure and to evaluate the audiometric results obtained. STUDY DESIGN AND SETTING: and patients Retrospective chart review in a tertiary referral center. Between September 1998 and October 2000, 23 titanium middle ear implants (23 TORP) were used for reconstruction of the ossicular chain after tympanomastoidectomy. Preliminary functional results were obtained in 23 cases. RESULTS: Average follow-up time was 18 months (range, 12-40) and no adverse reactions or extrusions occurred. Seven of 16 canal wall down tympanoplasties (43.7%), and 3 of 7 canal wall up tympanoplasties performed (42.9%) had a postoperative air-bone gap of between 0 and 10 dB. CONCLUSIONS: Preliminary results show that titanium prosthesis provide a promising hearing result after total ossicular reconstruction, although long-term results are not yet available. The low weight of these prostheses may be the reason for the decrease in the air-bone gap.

Adolescent↗
PubMed2005

Surface roughness and fatigue performance of commercially pure titanium and Ti-6Al-4V alloy after different polishing protocols.

STATEMENT OF PROBLEM: Surface quality of cast metal is directly related to service performance under fatigue stress. Surface heterogeneities resulting from either finishing or polishing processes or by corrosive agents such as fluoridated solutions, can negatively affect fatigue life. Cast titanium frameworks are difficult to polish, and an accepted polishing protocol has not been established. PURPOSE: This study evaluated and compared surface roughness of cast commercially pure titanium (CP Ti) and Ti-6Al-4V alloy submitted to conventional or electrolytic polishing, correlating the results with corrosion-fatigue strength testing performed in artificial fluoridated saliva. Specimens were also tested in air at room temperature to evaluate the effectiveness of the corrosion-fatigue test model. MATERIAL AND METHODS: For each metal, 40 dumb-bell-shaped rods, 2.3 mm in diameter at the central segment, were cast. Conventional polishing was performed on 20 specimens of each metal following the manufacturer's instructions. A source of continuous electrical current was used for electrolytic polishing of the other 20 specimens of each metal, which were immersed in an electrolytic solution containing 5% fluoridric acid, 35% nitric acid, and 60% distilled water. Surface roughness, Ra (microm), was measured with a profilometer, and fatigue tests were carried out with a universal testing machine using a load 30% lower than the 0.2% offset yield strength. After failure, the fractured surfaces were examined using scanning electron microscopy. Surface roughness means were analyzed with a 2-way analysis of variance and the Tukey multiple comparisons test (alpha=.05). RESULTS: Electrolytic polishing (0.24 +/- 0.05 microm) provided significantly (P <.05) lower surface roughness values than conventional polishing (0.32 +/- 0.06 microm). Regardless of the polishing protocol, surface roughness of Ti-6Al-4V alloy (0.25 +/- 0.06 microm) was significantly lower (P <.05) than that of CP Ti (0.31 +/- 0.05 microm), and the fluoridated environment did not influence fatigue performance. There was no correlation between fatigue performance and surface roughness. CONCLUSION: Surface roughness of Ti-6Al-4V was significantly lower than that of CP Ti. For cast titanium frameworks, the electrolytic polishing regimen was found to be more effective than the manufacturer's polishing instructions with abrasives and rotary instruments. After polishing, differences in surface roughness values did not affect corrosion-fatigue performance.

Alloys↗
PubMed2005

Custom-made laser-welded titanium implant prosthetic abutment.

A technique to create an individually modified implant prosthetic abutment is described. An overcasting is waxed onto a machined titanium abutment, cast in titanium, and joined to it with laser welding. With the proposed technique, a custom-made titanium implant prosthetic abutment is created with adequate volume and contour of metal to support a screw-retained, metal-ceramic implant-supported crown.

Ceramics↗
PubMedDate not supplied

Direct current stimulation of titanium interbody fusion devices in primates.

BACKGROUND CONTEXT: The fusion rate for anterior lumbar interbody fusion (ALIF) varies widely with the use of different interbody devices and bone graft options. Adjunctive techniques such as electrical stimulation may improve the rate of bony fusion. PURPOSE: To determine if direct current (DC) electrical stimulation of a metallic interbody fusion device enhanced the incidence or extent of anterior bony fusion. STUDY DESIGN/SETTING: ALIF was performed using titanium alloy interbody fusion devices with and without adjunctive DC electrical stimulation in nonhuman primates. METHODS: ALIF was performed through an anterolateral approach in 35 macaques with autogenous bone graft and either a titanium alloy (Ti-6Al-4V) fusion device or femoral allograft ring. The fusion devices of 19 animals received high (current density 19.6 microA/cm2) or low (current density 5.4 microA/cm2) DC electrical stimulation using an implanted generator for a 12- or 26-week evaluation period. Fusion sites were studied using serial radiographs, computed tomography imaging, nondestructive mechanical testing and qualitative and semiquantitative histology. RESULTS: Fusion was achieved with the titanium fusion device and autogenous bone graft. At 12 weeks, the graft was consolidating and early to moderate bridging callus was observed in and around the device. By 26 weeks, the anterior callus formation was more advanced with increased evidence of bridging trabeculations and early bone remodeling. The callus formation was not as advanced or abundant for the allograft ring group. Histology revealed the spinal fusion device had an 86% incidence of bony fusion at 26 weeks compared with a 50% fusion rate for the allograft rings. DC electrical stimulation of the fusion device had a positive effect on anterior interbody fusion by increasing both the presence and extent of bony fusion in a current density-dependent manner. CONCLUSIONS: Adjunctive DC electrical stimulation of the fusion device improved the rate and extent of bony fusion compared with a nonstimulated device. The fusion device was equivalent to or better than the femoral allograft ring in all evaluations. The use of adjunctive direct current electrical stimulation may provide a means of improving anterior interbody fusion.

Alloys↗
PubMed2006

Efficacy and safety of the use of titanium mesh cages and anterior cervical plates for interbody fusion after anterior cervical corpectomy.

BACKGROUND: To determine the safety and effectiveness of the use of titanium mesh cages (TMCs) and anterior cervical plates (ACPs) for interbody fusion after anterior cervical corpectomy. METHODS: From June 2001 to June 2003, 15 patients underwent reconstruction with TMCs and ACPs for interbody fusion after anterior cervical corpectomy in our hospital. The mean follow-up is 13.6 months (range, 9-24 months). Subjects included those with cervical degenerative, traumatic, or pathological diseases. Titanium mesh cages were filled with autologous bone grafts taken from the corpectomy and iliac crest bone chips and were all filled with triosite (calcium phosphate ceramics). The patients' observable signs, neurological reconstruction results, and complications were fully and explicitly recorded throughout the procedure. Radiological imaging studies for measurements of coronal and sagittal angles, sagittal displacements, and settling ratio changes were performed to evaluate spinal stability. We used axial cervical computed tomography (CT) and reconstructive sagittal cervical CT to demonstrate interbody fusion within titanium mesh. RESULTS: The alleviation and frequent disappearance of the subjects' original symptoms and the significant neurological recovery obvious in most patients indicated that postoperative spinal stability could be well maintained. No significant differences in mean cage height-related settling rates, mean sagittal displacements, and mean coronal and sagittal angle changes were observed between 1-level and multilevel corpectomy. All patients who received axial and reconstructive sagittal cervical CT scan could demonstrate true interbody fusion within TMC, and no nonunions were present. Cage malplacement was observed in one subject who had neck pain and neck stiffness, rather than from radiculopathy or myelopathy. One subject died of acute myocardial infarction. There were no ceramic-related complications. CONCLUSIONS: Based on preliminary findings from this study, reconstruction involving TMC interbody fusion with ACP fixation after anterior cervical corpectomy serves as an effective and safe method for the treatment of cervical disease.

Adult↗
PubMed1978

The comparison of steel and titanium dynamic compression plates used for internal fixation of 256 fractures of the tibia.

A consecutive series of 256 fractures of the shaft of the tibia treated by internal fixation with a narrow dynamic compression plate (DCP) is presented. In 123 cases the plates were made of titanium and in 133 cases they were made of stainless-steel. In both groups the age distribution of the patients, the period between operation and the final review and the time of removal of the metal were comparable. All these fractures resulted from skiing accidents. Eighty-six per cent of the 256 fractures were reviewed between 1 and 2 years after the operation. Ninety-one per cent of the titanium group and 93 per cent of the stainless-steel group showed full recovery without any loss of movement in the joints. In both groups there was the same number of refractures, which were chiefly due to subsequent accidents. There were no cases of local wound infection, osteitis or non-union. Furthermore, there was no difference to be seen between the radiological patterns of fracture healing in the two groups. In this series stainless-steel and titanium plates gave the same excellent results.

Adult↗
PubMed2000

Shear bond strengths of polymethyl methacrylate to cast titanium and cobalt-chromium frameworks using five metal primers.

STATEMENT OF PROBLEM: Poor chemical bonding of a denture base resin to cast titanium frameworks often introduces adhesive failure and increases microleakage. PURPOSE: This study examined the shear bond strengths of a denture base resin to cast pure titanium, Ti-6Al-4V, and a cobalt-chromium alloy using various adhesive primers. MATERIAL AND METHODS: Disks (6.0 mm diameter, 2.5 mm thick) were cast of the 3 alloys. The disk surfaces were grit-blasted with 50 microm alumina and treated with 5 different metal primers (Metal Primer II ¿MP]; Cesead Opaque primer ¿OP]; Meta Base ¿MB]; experimental primer ¿EP]; Siloc bonding system ¿SI]). A denture base resin (Palapress Vario) was then applied on the disks with hole-punched sticky tape (bonding area of 5.0 mm) and a Teflon (PTFE, New Age Industries Inc, Willow Grove, Pa.) ring (6.0 mm diameter x 2.0 mm thick). Specimens without primer were also prepared as controls. All specimens were immersed in 37 degrees C water and thermocycled up to 2,000 cycles. Shear bond strength values were determined at a crosshead speed of 0.5 mm/min. Data were statistically analyzed using 3-way ANOVA, followed by 1-way ANOVA and the Scheffé multiple range test. RESULTS: Primers significantly (P <.05) improved shear bond strengths of denture base resin to all metals, among which no significant differences were found. Specimens primed with OP, MP, and EP showed higher bond strengths than did those primed with MB. After thermocycling, the bond strengths of MB and SI decreased substantially; MB showed the least durability (22.8% to 35.5% decrease) among the primers. CONCLUSION: The application of 5 primers significantly improved the shear bond strengths of a denture base resin to cast CP titanium, Ti-6Al-4V, and Co-Cr alloy. OP and MP primers exhibited greater bond strength and durability than did MB and SI.

Analysis of Variance↗
PubMed1995

Adsorption of salivary proteins onto prosthetic titanium components.

In vivo adsorption of salivary proteins onto prosthetic titanium components was analyzed after exposure of titanium abutments to the oral environment for a period of 2 to 6 weeks. Gel electrophoresis and Western immunoblotting were used to separate and identify the proteins, which were mainly alpha-amylase and serum albumin. Selective adsorption of proteins enables attachment of specific oral bacteria and thus may alter the composition of the dental plaque formed on titanium surfaces.

Adsorption↗
PubMed1996

Hardness, strength, and ductility of prefabricated titanium rods used in the manufacture of spark erosion crowns.

Depending on the size of the prepared tooth spark eroded and milled, Procera crowns (Nobelpharma AB, Göteborg, Sweden) are manufactured from one of five diameters of pure titanium rods. In this study microindentation hardness tests were performed on the outer 400 microns and center of 10 samples for each type of rod. Five tensile samples were also machined for each of the diameters and tested in tension in a universal testing machine. Cast titanium samples were similarly prepared and tested. Some significant differences in hardness and considerable differences in strength and ductility were identified between the prefabricated rods. In comparison, cast titanium was significantly harder and stronger but less ductile.

Analysis of Variance↗
PubMed1997

A short-term clinical follow-up study of superplastic titanium alloy for major connectors of removable partial dentures.

STATEMENT OF PROBLEM: Superplastic forming of Ti-6A1-4V alloy has been used in the fabrication of a removable denture framework. The method provides the titanium alloy denture framework with excellent physical properties not seen in cast titanium prostheses. PURPOSE: This study describes the technical procedure for fabricating removable dentures with this type of framework and evaluates clinical applications of the dentures in short-term follow-up periods from 6 months to 3 years. RESULTS: Results of this study demonstrated that the dentures functioned well and did not cause any major clinical difficulties. The patients have expressed satisfaction with the dentures at regular recall appointments. CONCLUSION: The clinical observations suggest that this method is suitable for fabricating titanium alloy removable dentures.

Acrylic Resins↗
PubMed1998

Phosphate and thiophosphate primers for bonding prosthodontic luting materials to titanium.

STATEMENT OF PROBLEM: When resin-bonded prostheses are constructed with titanium, they must be strongly bonded with luting materials for the prostheses to withstand the oral environment over the long term. However, limited information is available about the bond durability between luting materials and titanium. PURPOSE: This study determined whether a phosphate and two thiophosphate primers increase bond strength and durability between a commercially available pure titanium and four luting agents. MATERIAL AND METHODS: Three primers and four luting agents were divided into three groups according to the type of acidic monomers: carboxylic acid derivatives (4-META, 4-AET, and MAC10), a phosphoric acid derivative (MDP), and a thiophosphoric acid derivative (MEPS). Disk specimens were bonded with 16 combinations of 3 primers and 4 luting agents, including 4 controls. Shear bond strengths were determined after 1-day immersion in water and after thermocycling for 100,000 cycles. RESULTS: Bond strengths were influenced by thermocycling, primer, luting agent, and their combinations. After thermocycling, the groups that demonstrated the highest bond strengths were six combinations of two primers (Cesead Opaque Primer and Metal Primer II) and three luting agents (Imperva Dual, Panavia 21, and Super-Bond C&B).

Analysis of Variance↗
PubMed1999

Pilot study of the effects of three bonding systems on the torsional resistance of a titanium-reinforced composite core.

STATEMENT OF PROBLEM: There are no studies analyzing the effects of a bonding agent on torsional resistance for a titanium-reinforced core material bonded with a multistep bonding system. PURPOSE: This pilot study investigated the effects of multistep bonding agents on torsional resistance of a titanium-reinforced composite core material (Ti-Core core material). MATERIAL AND METHODS: A total of 40 recently extracted human molars with their crowns removed were placed into acrylic resin blocks and divided into 4 groups of 10 specimens. Only multistep bonding systems were used (AllBond-2, ScotchBond Multi- PURPOSE: Tenure A&B, and the control without bonding agent). Specimens were prepared according to manufacturer's instructions. The control group was etched with a 37.5% phosphate acid. All cores were fabricated with Ti-Core titanium core material with No. 1 hard copper bands as the matrix. Ti-Core core material was applied and allowed to cure for 1 hour, then the cores were placed in 100% humidity (water) for 1 week. Test specimens were placed in a special jig and a clockwise torsional force applied. Torsional force was measured on a Lebow 1102-200 torque transducer and recorded on a Hewlett Packard 7015B X-Y recorder in inch x ounce then converted into Newton-meter. One-way analysis of variance (ANOVA) was used to test for statistical significance (P <.05). RESULTS: Torsional values (Newton-meter) were AllBond-2, 0.1980, ScotchBond Multi- PURPOSE: 0.1890, Tenure A&B, 0.2142; the control group recorded a value of zero. Statistical analysis revealed that bonding systems did not differ from one another. CONCLUSION: Use of a bonding agent increased the core's resistance to torsional forces. Lack of a bonding agent dramatically reduced the resistance to torque.

Analysis of Variance↗
PubMed1999

Investigation of the effect of three sprue designs on the porosity and the completeness of titanium cast removable partial denture frameworks.

STATEMENT OF PROBLEM: Although titanium has been used to cast removable partial denture frameworks, the casting process is arduous and requires specialized equipment. PURPOSE: This study evaluated the ability of 3 sprue designs (tree, ball, and circular) to produce complete, void-free castings of removable partial denture frameworks made from commercially pure titanium. METHODS AND MATERIAL: A cast with a Kennedy class III, modification 1, partially edentulous arch was used. The blocked-out cast was modified to facilitate assessment of the completeness of the casting of the clasp arms. Thirty refractory casts were made, and 10 wax patterns for each sprue design were fabricated and invested with ethyl silicate investment. Castings were made with an arc-type automatic casting machine in an argon atmosphere. Castings were examined with radiographic equipment to detect the presence of voids in the castings, and the completeness to each casting was visually verified. Data on porosities were tabulated and statistically analyzed with 1-way ANOVA followed by Student Newman-Keuls test. Chi-square analysis was used to identify statistically significant differences in casting defects among the 3 sprue designs. RESULTS: No statistically significant differences in the total number of porosities were found between the 3 sprue designs (P =.51). Results of completeness of castings evaluated by using chi-square test revealed a statistically significant deference among the 3 sprue designs (P =.008). CONCLUSION: The ball-sprue design produced the most complete castings for the removable partial denture titanium frameworks.

Analysis of Variance↗
PubMed1999

Effect of surface contamination on adhesive bonding of cast pure titanium and Ti-6Al-4V alloy.

STATEMENT OF PROBLEM: There is little information regarding bond strengths of resin cements to cast titanium surfaces contaminated by investment material. PURPOSE: This study examined the effect of surface contamination on the shear bond strength of resin cements to cast titanium and Ti-6Al-4V alloy. MATERIAL AND METHODS: Two types of disks were cast from commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy ingots using an argon-arc pressure casting unit and a phosphate-bonded Al2 O3 /LiAlSiO6 investment. After casting, disks were subjected to 3 surface treatments: (1) cast surface sandblasted (50 microm-sized Al2 O3 ) for 30 seconds; (2) metal surface sanded with silicon-carbide paper (600 grit) after grinding the contaminated cast surface (approximately 200 microm in thickness); and (3) metal surface sandblasted for 30 seconds after treatment 2. Surface structures were examined after each treatment with SEM and optical microscopy. Each type of disk was then bonded with 2 types of luting materials. Bonded specimens were subjected to thermocycling for up to 50,000 cycles, and shear bond strengths were determined after 0 (baseline) and 50,000 thermocycles. Results were statistically analyzed with 3-way ANOVA (P <.05). RESULTS: Microscopic observation of cast CP-Ti and Ti-6Al-4V exhibited noticeable structures on the cast surfaces apparently contaminated with investment material. However, there were no statistical differences (P >.05) in the bond strengths of both cements between contaminated (treatment 1) and uncontaminated surfaces (treatment 3) for both metals at baseline and after 50,000 thermocycles. The bond strength of specimens sanded with silicon-carbide paper (treatment 2) deteriorated dramatically after 50,000 thermocycles. CONCLUSIONS: Contamination of the cast metal surfaces by elements of the investment during casting did not affect bond strengths of the luting materials to CP-Ti and Ti-6Al-4V.

Alloys↗
PubMed2000

Preliminary experience with anterior cervical microdiscectomy and interbody titanium cage fusion (Novus CT-Ti) in patients with cervical disc disease.

BACKGROUND: Although the use of intervertebral fusion after anterior microdiscectomy in cervical disc disease remains controversial, a new surgical device is proposed for use in intervertebral fusion instead of bone graft. METHODS: This retrospective study at the Department of Neurosurgery, Cardarelli Hospital, Naples, from January 1993 to December 1998, compares the results of surgery on 58 patients with anterior microdiscectomy and intervertebral bone graft fusion (Group A) (ADIBG) with a group of 52 patients who underwent anterior microdiscectomy and intervertebral titanium cage fusion (Group B) (ADITC) in cervical radiculopathy and spondylotic myelopathy. In both groups a "radical discectomy" was performed under the operating microscope. In group A, interbody fusion was performed with autologous tricortical bone graft. In group B, a new type of titanium device (Novus CT-Ti) was used (Sofamor Danek Group). RESULTS: There was no collapse or extrusion of the device and no complications at the donor site (the bone fragments used to fill the cage were taken from osteophytes or vertebral body fragments). The use of this device provides immediate stabilization, reduces or eliminates pain, promotes bone fusion between the vertebrae adjacent to the cage by allowing bone growth through the cage, reestablishes and maintains the intervertebral space, reduces the average hospitalization time, and allows a quicker return to work. CONCLUSIONS: Patients who underwent ADITC did well and benefited from the surgery. Those who underwent ADITC did better than those who underwent ADIBG in regard to function, relief from pain, and complications. Early and good stability of the cervical spine seems to be the main advantage of using titanium cages.

Cervical Vertebrae↗
PubMed1997

Torsional properties of nickel-titanium versus stainless steel endodontic files.

The purpose of this study was to evaluate and compare the torsional properties of stainless steel K-type .02 taper and nickel-titanium U-type .02 and .04 taper instruments. Torsion tests were performed on all three designs of instruments according to ANSI/ADA specification number 28. For each design, 20 instruments of each of three sizes (15, 25, and 35) were tested. The three parameters measured were maximum torque, torque at failure, and angular deflection. Stainless steel K-type .02 taper and nickel-titanium U-type .02 and .04 taper instruments met or exceeded specification standards for maximum torque. They also satisfied and far exceeded the standards for angular deflection at the failure point. The stainless steel instruments showed no significant difference between maximum torque and torque at failure, whereas both of the nickel-titanium instruments showed a significant differential between maximum torque and torque at failure.

Analysis of Variance↗