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PubMed1975

[Titanium, steel and their combination in bone surgery].

The combined application of Titanium plates with stainless steel screws appeared interesting, making a more elastic plate available without the risk of screw fractures. 3 different combinations of Titanium und stainless steel implants were tested in the animal and on humans. A morphometric evaluation of the soft tissue (animal) gave similar good results for stainless steel implants as for the combination of Titanium and steel, while pure Titanium gave the best result. Atomic absorption tests (human) showed that in case of the Titanium/steel mixture only the stainless steel screws did corrode. Delayed fracture healing or mechanical instability always gave risk to more metal deposits in the soft tissue than primary bone healing. If the advantages of Titanium seem important and if the rigidity of stainless steel screws may not be missed, the combination of the two metals appears possible and without danger.

Alloys↗
PubMedDate not supplied

Oxidized titanium screws coated with calcium ions and their performance in rabbit bone.

PURPOSE: The aim was to answer a fundamental question: Do the chemical properties of titanium implants influence osseointegration? MATERIALS AND METHODS: Screw-type implants produced of turned commercially pure (grade 1) titanium (controls) and electrochemically calcium-deposited titanium implants (Ca test implants) were placed in the tibiae and femora of a total of 10 mature New Zealand white rabbits. The macro arc oxidation method was applied for Ca implants. Surface oxides were characterized with different analytic techniques, including x-ray photoelectron spectroscopy, auger electron spectroscopy, scanning electron microscopy, thin-film x-ray diffractometry, and TopScan 3D. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. RESULTS: After a follow-up period of 6 weeks, test Ca implants showed a significant increase in mean peak removal torque (P = .0001) and in the histomorphometric measurement of bone-to-metal contact around the implants (P = .028) in comparison to controls. In addition, more mature mineralized bone was observed adjacent to test Ca implants compared to controls, as evaluated on 10-microm undecalcified, toluidine blue-stained, cut, and ground sections. DISCUSSION: The potential role of surface Ca chemistry to a superior bone response is discussed with specific reference to interaction with Ca(+)-binding proteins and function as binding sites of calcium phosphate mineral. CONCLUSION: The present results suggest that the surface chemical composition of titanium implants is of great importance for the bone response. Ca ion-deposited titanium implants showed fast and strong osseointegration in the rabbit bone model.

Animals↗
PubMedDate not supplied

Titanium deposition after peri-implant care with the carbon dioxide laser.

PURPOSE: Titanium endosseous implants are becoming increasingly important in dentistry because of their excellent long-term results. However, it has been reported that these implants may lead to higher concentrations of titanium, especially in the lungs and kidneys. The purpose of this study, therefore, was to determine whether CO2 laser-assisted decontamination of exposed implant surfaces is associated with an increase in titanium release. MATERIALS AND METHODS: In 6 beagle dogs, a total of 60 implants were placed. After osseointegration and second-stage surgery, peri-implantitis was induced by cotton floss ligatures for 12 weeks. Surgical treatment consisted of granulation tissue removal, including decontamination of the implant surface with 3 different methods. Twenty implants were decontaminated conventionally by an air-powder abrasive for 60 seconds. Another 20 implants were decontaminated by laser treatment alone. The last 20 implants were treated conventionally by air-powder abrasive and then lased. Four months later, fresh tissue samples of various tissues were evaluated by histologic and chemical analysis. RESULTS: Quantitative analysis indicated that titanium accumulation could be detected, especially in the spleen, liver, oral mucosa, regional lymph nodes, lung, and kidney in the beagle dog model. DISCUSSION: The concentrations found did not exceed those previously reported in the literature. CONCLUSION: These results support the hypothesis that CO2 laser-assisted therapy of ailing implants will not result in excessive titanium concentrations in tissues. Accordingly, CO2 lasers appear suitable and safe for peri-implant gingival surgery.

Air↗
PubMed2001

[Effects of the mold temperature on the castability of titanium zirconium alloy for dental clinical use].

OBJECTIVE: The aims of this study were to investigate the influence of the mold temperature on the castability of Ti-Zr alloy and find out the reasonable method for casting Ti-Zr alloy in clinic. METHODS: Ti-Zr alloy, pure titanium and Ti-6Al-4V alloy were casted respectively, by using a mold made of a zircon (ZrO2.SiO2) investment and a casting machine (China) designed, with a program of vacuum, pressure and centrifuge casting at three mold temperatures (room temperature, 300 degrees C, 600 degrees C). The castability value was obtained by counting the complete segment of the cast alloy grid. The wax pattern provided a grid with 112 segments. The percentage of complete cast segments was calculated by divided by 112, and multiplied by 100. The mesh castability values of Ti-Zr alloy, pure titanium and Ti-6Al-4V alloy were examined. RESULTS: The castability of three titanium alloys was high when the mold temperature was high. The castability values of Ti-Zr alloy at three mold temperatures were 88.57% for the room temperature, 94.55% for 300 degrees C, and 96.67% for 600 degrees C. Ti-Zr alloy casted at the room temperature showed significantly lower castability value than that casted at 300 degrees C and 600 degrees C (P < 0.05), but no significant difference was found between the castability values of 300 degrees C and 600 degrees C (P > 0.05). The castability values of pure titanium at three mold temperatures were 95.33% for room temperature, 98.70% for 300 degrees C, and 98.90% for 600 degrees C. The castability values of Ti-6Al-4V alloy at three mold temperatures were 95.37% for room temperature, 96.00% for 300 degrees C, and 98.78% for 600 degrees C. When casted at room temperature, the castability values of Ti-Zr alloy were significantly decreased comparing with those of pure titanium and Ti-6Al-4V alloy (P < 0.05), but no significant difference was found when cast alloys were casted at 300 degrees C and 600 degrees C (P > 0.05). CONCLUSION: The mold temperature is one of the major factors influencing cast quality. This study suggests that in order to obtain high castability of dental Ti-Zr alloy castings in clinic, the optimal mold temperature should be higher than 300 degrees C.

Dental Alloys↗
PubMed2002

[Preparation of thin hydroxyapatite layers on cp titanium through anodic oxidation followed with hydrothermal treatment].

To study the method of anodic oxidation followed by hydrothermal treatment for cp titanium and to know bone response to thin hydroxyapatite layers in vivo, commercially pure titanium plates were anodized at 200 V-400 V with direct electric current density no more than 50 mA/cm2 for 15 minutes in the electrolytic trough. beta-glycerophosphate sodium(0.03-0.04 M) and calcium acetate(0.2-0.3 M) were used as electrolytes. Then, titanium plates were hydrothermal treated in the autoclave for 2 hours at 280 degrees C-300 degrees C. Polishing and grit-blasting surface was used as control to learn bone response to thin layers. Twelve rabbits were evenly divided into 3 groups, each group was implanted with 12 implants into the rabbits femoral bone. After 4, 8 and 16 weeks, implants were taken out and collected respectively and were made grinding slices. The bone-implant interface was observed with light microscope. And the bone-implant interface of polishing and layered implants after 8 weeks implantation was observed with scanning electron microscope. The element contents at the interface of polishing and layered implants before and after 8 weeks implantation were detected with EDAX. Results showed that there was hydroxyapatite(HA) precipitated on the titanium surfaceamellae bone in 8 weeks for thin HA coatings, and no HA debris were found at the interfacial zone. In addition, Ca and P content on the hydrothermal treated implant surface increased much more after implantation than that of polished implants. It was concluded that anodic oxidation followed by hydrothermal treatment could precipitate thin hydroxyapatie layer on the surface of cp titanium, which could improve early formation of woven bone and accelerate woven bone transferring to lamellae bone at the implanted site.

Animals↗
PubMed2003

[Effect of chondroitin sulfate-A attached titanium surface on culture osteoblast].

OBJECTIVE: To investigation the in vitro effect of CS-A attached titanium surface on the culture of osteoblast. METHODS: We examined the cell proliferation, the ALP activities, and the Calcium contents in the Ostelblast cultured on the Titanium surfaces attached with different concentrations of CS-A Calcium. RESULTS: The CS-A promots the proliferation of osteoblast and increases the calcium content on the titanium disks. CONCLUSION: The biocompatibility of titanium was improved after CS-A attached titanium surface.

Biocompatible Materials↗
PubMedDate not supplied

Implant-supported laser-welded titanium and conventional cast frameworks in the partially edentulous law: a 5-year prospective multicenter study.

PURPOSE: This study evaluated and compared the clinical performance of laser-welded titanium fixed partial implant-supported prostheses with that of conventional cast frameworks in the partially edentulous jaw. MATERIALS AND METHODS: Forty-two patients provided with Brånemark system implants were arranged into two groups. Twenty-one patients (group A) were provided with a conventional cast ceramometal framework in one side of the jaw and a laser-welded titanium framework with low-fusing porcelain in the other side. In group B, 21 patients received a titanium framework prosthesis to replace a conventional implant prosthesis. Clinical and radiographic data were collected for 5 years. RESULTS: Four implants and one titanium framework were lost during the follow-up period. The two framework designs did not show any significant differences with regard to implant or prosthesis survival (P > .05). Few clinical complications were observed. In group A, marginal bone loss after 5 years was similar for both prosthesis designs, with an average of 0.1 mm and 0.3 mm in the maxilla and mandible, respectively. Basically, no bone loss was observed on average in group B. Furthermore, no significant relationship was observed between marginal bone loss and placement of prosthesis margin or prosthesis design. CONCLUSION: Except for an insignificant tendency toward a slightly higher incidence of small chips of porcelain veneers, laser-welded titanium frameworks presented an overall similar clinical performance as conventional cast frameworks in partial implant situations after 5 years.

Adult↗
PubMed1992

[A comparative study of the characteristics of femoral hip prosthesis heads--study and results ceramic-coated hip joint heads of titanium].

Today, only hard/soft cup and femoral head combinations are employed for hip joint prostheses. Highly polished ceramic is a material with very good tribological properties for femoral heads, being highly resistant to mechanical wear and tear, and highly resistant to chemical reactions in the biological environment. The advantage of metal heads, in contrast, undoubtedly lies in their resistance to breakage and the ease with which their geometry can be modified with respect, for example, to antirotation angle and neck length. The ideal material for femoral heads is a combination of the two materials. The new multi-layer combination of titanium-niobium oxide/nitride ceramic coating applied to a prehardened titanium head combines the positive material properties in an ideal manner. Femoral heads made of CoCrMo, oxide-hardened titanium, aluminium oxide or multilayer titanium-niobium ceramic were compared by means of friction an wear and tear tests. The TiNb-ceramic-metal heads showed similar abrasion at the surface as the ceramic heads. At the high loads of more than 400 kp, which may also be reached under physiological conditions, the specially coated titanium-ceramic heads proved to be superior in terms of resistance to fracture and tribological properties.

Biomechanical Phenomena↗
PubMedDate not supplied

Effect of surface conditioning techniques on the resistance of resin composite core materials on titanium posts.

OBJECTIVE: This study evaluated the resistance of various post and core materials against torsional forces on differently conditioned titanium posts. METHOD AND MATERIALS: One hundred fifty pure titanium posts (DIN 17850-Ti4/3.7065) were conditioned utilizing Silicoater Classical, Silicoater MD, Rocatec, Kevloc, and Siloc. Subsequently, three post and core materials (Adaptic, Coradent, Ti-Core) were applied to titanium posts that were previously coated with a light-cured opaquer (Dentacolor). Thirty sandblasted titanium posts were used as reference for each core material. Following thermocycling (5 degrees C to 55 degrees C, for 30 seconds or 5,000 cycles), maximum torsional forces were determined with an electronic torque movement key. RESULTS: Kruskal-Wallis, Mann-Whitney U-tests indicated significant differences between Adaptic, Coradent, Ti-Core (20.9 dNm, 18.84 dNm, and 18.62 dNm, respectively). There were no significant differences between Silicoater Classical (18.56 dNm), Silicoater MD (18.18 dNm), and Rocatec (16.95 dNm), while Siloc exhibited the highest results (20.44 dNm). Kevloc demonstrated significantly lower results (10.43 dNm) than those of other systems and the control group (14.49 dNm). CONCLUSION: Resistance of core materials against torsional forces on titanium posts increased with the use of chemical surface conditioning techniques, while the system using only acrylization did not improve the resistance in comparison to the unconditioned posts.

Acrylonitrile↗
PubMedDate not supplied

Bending resistance of prefabricated titanium posts following molten cast core attachment.

Posts and cores are used to restore endodontically treated teeth that have substantial loss of the coronal tooth structure. This in vitro study was designed to determine the mechanical properties of prefabricated titanium posts following attachment of their metal cores by molten casting (caston). Prefabricated tapered titanium posts (ER post-restoring system, Komet, Lemgo, Germany) in three diameter sizes (ISO 50, 90, 110) (n=9) were cast over with the metal cores of three different alloys (Au-Ag-Pt, Au-Pt-Pd, Co-Cr-Mo). Also, posts of each size were precision fit into the central core channels of the different cast metal cores to serve as control specimens. The 0.2% yield strengths (R0.2) of all specimens were tested on a universal testing machine. Statistical analyses of the results were carried out with an analysis of variance (ANOVA, one-way, two-way) and Bonferroni-Dunn's multiple comparisons post-hoc analysis for test groups (alpha=0.05). There was a significant decrease in yield strength (p<0.05) as a result of casting the various metals over the different post sizes, considered to be due to the detrimental thickening and porosity formation of the titanium surface oxide layer. Twenty-one percent, 51% and 33% reduction in yield strength, respectively, was obtained for the ISO 50, ISO 90 and ISO 110 cast-on groups relative to controls (p<0.05). Statistically significant differences in various core alloys were found only for the Au-Ag-Pt alloy compared to the Co-Cr-Mo alloy (post size ISO 50) and the Au-Pt-Pd alloy compared to the Co-Cr-Mo alloy (post size ISO 110) (p>0.05). Prefabricated titanium posts with metal cores cast over them showed inferior mechanical properties compared to precision-fit posts. These results indicate greater strength of the titanium posts when their cast cores were attached mechanically rather than by the molten casting method.

Crowns↗
PubMed2004

[Failure rate and revision surgery in ossiculoplasty with Kurz titanium prosthesis].

UNLABELLED: Despite its excellent biocompatibility, failures and in particular extrusion of the prosthesis have been described in ossiculoplasty with titanium prosthesis. OBJECTIVE: Report our experience with revision ossicular recontruction in ossiculoplasty with Kurz prosthesis. Identify causes of failure in ossiculoplasty using the titanium prosthesis. MATERIAL AND METHODS: Retrospective chart reviews were performed for 110 patients who had undergone titanium ossicular implants between November 1998 and 2002. All patients had undergone ossiculoplasty using titanium middle ear implants. Patients were divided into 2 groups: in group 1 patients underwent revision ossiculoplasty; in group 2 patients had a successful surgery at first stage. Anatomic and functional results have been studied in these two groups. Causes of failures were analysed. RESULTS: The overall failure rate was 20% (22/110). Twenty patients underwent revision ossiculoplasty. Nine primary failures were attributable to a short implant. Two extrusions were observed. At long term billow-up, the functional gain between the primary and revision ossiculoplasty was comparable. CONCLUSION: Revision ossiculoplasty is worthwhile for those patients who have failure of the titanium prosthesis in ossiculoplasty. A large cartilage graft interposition is necessary to prevent extrusion. The overall luxation rate observed in our series was mainly due to a too short prosthesis and we recommend now a reconstruction with longer prosthesis.

Adult↗
PubMedDate not supplied

Surface analysis and effects on interfacial bone microhardness of collagen-coated titanium implants: a rabbit model.

PURPOSE: The aim of this study was to evaluate the surface chemistry and the microhardness at the implant-bone interface using a recently developed collagen-coated titanium implant in a short-term rabbit model. MATERIALS AND METHODS: Surface chemistry was evaluated by x-ray photoelectron spectroscopy (XPS), while in vivo studies involved 4-week implants mid-diaphysis in the lateral femurs of adult male rabbits. After conventional embedding and evaluation of histologic sections, the resinembedded blocks containing the implanted screws were used to measure bone hardness by means of an indentation test. RESULTS: Decomposition of the C1s peak obtained by XPS analysis confirmed that surface-immobilized collagen retained all the molecular features of the control, nonimmobilized reference. As to microhardness measurement, newly formed bone at the collagen-coated-implant/bone interface was significantly harder than bone at the interface of the uncoated control implant and bone. DISCUSSION: These results suggested that collagen coating significantly improves bone maturation and mineralization at the interface in comparison with uncoated commercially pure titanium. Surface modification of titanium implants by collagen coating has recently been discussed as a promising approach to the biochemical modification of implant surfaces. The present results support previous histologic findings and demonstrated that the biomolecular layer linked over the titanium implant can increase the bone healing rate, at least in this animal model. CONCLUSIONS: The present microhardness measurement at the bone-implant interface showed that collagen coating can significantly improve bone maturation and mineralization at the interface in comparison with uncoated commercially pure titanium, confirming and substantiating previous findings by histomorphometric measurements from the same model.

Animals↗
PubMed2005

[The electrochemical behavior of titanium and dental casting in modelling oral conditions].

The electrochemical behavior of titanium and dental casting alloys in modelling oral conditions With applying dental implants in the oral cavity the direct contact of various metals (titanium and other casting alloys) is unavoidable. Considering the electrolyte characteristic of the saliva, the chances are given that electrochemical processes might occur under such circumstances. The aim of this study was to investigate the electrochemical behavior of titanium and other dental alloys being in direct contact with the oral environment. Nickel-chromium, cobalt-chromium, high palladium content and gold alloys as well as CP grade I titanium cast samples respectively were involved in the study. Test models were made from these metals. As an electrolyte solution (set to pH 4) artificial saliva and 0.9 % NaCl solution were used. The type and the rate of corrosion were assessed with laboratory immersion test and electrochemical polarization method. In case of polarization method a three-electrode measuring-cell was applied. Laboratory exposure tests revealed that titanium resisted corrosion; there was no sign of corrosion at all. The high palladium content alloy and gold alloy behaved similarly. The nickel-chromium and cobalt-chromium alloys showed some signs of corrosion, especially in sites with damaged surface or inhomogeneities on the surface. Results of the laboratory electrochemical experiments correlated with immersion studies graphically illustrated in the paper.

Biocompatible Materials↗
PubMed2006

[Comparison between solis fixation fusion and titanium plate fixation by cervical anterior approach].

OBJECTIVE: To investigate the effect difference between the Solis fixation fusion and the titanium plate fixation by the cervical anterior approach after decompression and bone graft implantation. METHODS: Of the 104 patients with cervical disease from September 2001 to March 2004, 36 were treated with the Solis implantation after decompression by the cervical anterior approach, and 68 were treated with the titanium plate fixation after decompression and bone graft implantation. The recovery of the neurological function in all the patients were assessed with the JOA Scoring at 6 weeks, 3, 6, 12, 24 and 36 months. The fragment fusion and its stability as well as the changes in the intervertebral height were assessed with X-ray examination. RESULTS: According to the JOA Scoring, the excellent and good outcomes accounted for 94.4% in the Solis group and 94.1% in the titanium plate group. In all the patients, the fragment fusion was achieved in 3 months. The change in the Cobb angle of the fused fragment was less than 5 degrees at the flexion-extension posture, 3.6 +/- 0.8 degrees in the Solis group, 2.4 +/- 0.7 degrees in the titanium plate group. There was significant differences between the two groups (P < 0.05). The intervertebral height of the operation fragment in the Solis group increased 1.6 +/- 0.7 mm, which was higher than that in the titanium plate group (P < 0.05). CONCLUSION: Clinical effects of the two internal fixation operations are good; however, the Solis fixation has more advantages because of its simpler performance, less trauma, and fewer complications.

Adult↗
PubMed2006

Cyclic loading of endodontically treated teeth restored with glass fibre and titanium alloy posts: fracture resistance and failure modes.

The aims of this in-vitro investigation were to compare the fracture resistance and the failure modes of endodontically treated teeth restored with glass fibre-reinforced posts with those of teeth restored with titanium-alloy posts. A total of 60 single-rooted human mandibular premolars were endodontically treated. The teeth were divided into two experimental and one control group. Post spaces 9mm long were prepared in the roots of the experimental groups in which glass fibre-reinforced posts (Group A) and titanium-alloy posts (Group B) were cemented. In the control group (Group C), no post was inserted. The specimens were stored in normal saline for a period of three weeks before being intermittently loaded at an angle of 30 degrees degrees to the long axis of the tooth at a frequency of two loads of 40N per second. Log-rank test used for the overall analysis revealed that there was no significant difference of fracture resistance between teeth restored with glass fibre-reinforced posts (Group A) and titanium-alloy posts (Group B). The survival of the control group was found to be significantly inferior to that of the experimental groups. There was no significant difference in the number of failures between the two experimental groups. There was significantly more core and post failure for the glass fibre-reinforced posts, root and core failure for the titanium-alloy posts and core failure for the control group. The results suggest that post failures are more frequent in teeth restored with quartz fibre posts and root fractures are more frequent in teeth restored with titanium posts.

Bicuspid↗
PubMedDate not supplied

[Can steel screws be combined with titanium plates? Hard polishing technique and SEM in animal experiments].

To clarify the compatibility of steel and titanium, mandibular resections were performed on 24 sheep and the defects bridged with titanium plates and steel vs. titanium screws. 6, 12 and 24 weeks after osteosynthesis the implants were removed along with the surrounding bone segment and thin ground sections were prepared using the Donath method. The sections were then studied by light, fluorescence, polarization and scanning electron microscopy. The stability and easy removal are advantages of steel screws rendering them particularly suitable for temporary implantations. Moreover, they are 50-75% less expensive than titanium screws. After 3 and 6 months some minimum friction corrosion was observed at the screw/plate interface of steel screws. None of the specimens, however, showed signs of local tissue damage such as metallosis. From this it may be concluded that at least on a temporary basis a combination of steel screws and titanium plantes seems to be possible.

Animals↗
PubMed1991

[The influence of the titanium implant surface on the process of osseointegration].

In this study the influence of physically different titanium implant surfaces (smooth, rough-textured, porous-coated) on osseointegration was examined. Embryonic chick calvarial osteoblasts were cultured on the various titanium disks in vitro. Synthesis of extracellular matrix and mineralization were evaluated. Osteoblasts cultured on rough-textured and porous-coated titanium disks exhibited substantially higher rates of bone-specific extracellular matrix synthesis (collagen) and subsequent mineralization than the osteoblasts on smooth titanium disks or plastic tissue culture dishes as controls. From this it can be concluded that porous or rough titanium implant surfaces may act like "natural" substrates permiting microscopic tissue/cell ingrowth and thus improving clinical implant fixation.

Animals↗
PubMed1991

The effect of oral topical fluorides on the surface of commercially pure titanium.

This study investigated the risk of corrosion of titanium abutments by the accidental or unauthorized use of preventive fluorides in the mouth. Polished test pieces of commercially pure ASTM grade 1 titanium were immersed in topically used fluorides (toothpaste, gel, and varnish). They were brushed in vitro with toothpaste and gel, corresponding to the time and effect of brushing with toothpaste twice a day for 6 years and with gel once a week for 12 years. Results indicate that an aminofluoride toothpaste with low ionizable fluoride content (0.125%) used in brushing natural teeth does not cause deterioration of the titanium abutments in the same mouth if the titanium is grade 1 purity. Carefully controlled use of fluoride gel (F 1.25%) and varnish (F 2.25%) is likewise not dangerous. The mechanical abrasion caused by toothbrush bristles appears to be the main deteriorating factor for the titanium surface.

Corrosion↗