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PubMed2006

Radiographic assessment of bone density around integrated titanium implants after ovariectomy in rats.

OBJECTIVES: This study evaluated the influence of ovariectomy 8 weeks after implant placement on bone integrated to titanium implants. MATERIAL AND METHODS: Thirty-eight female rats were submitted to a titanium implant at the tibiae proximal methaphysis. After a healing period of 8 weeks the animals were randomly divided into three groups: control (CTL-10 animals), sham-operated (SHAM-14 animals) and ovariectomy (OVX-14 animals). The CTL group was then sacrificed in order to confirm integration of the implant. The SHAM group was submitted to fictitious surgery and the OVX group was submitted to bilateral ovariectomy. After 12 weeks post-implant placement, the SHAM and OVX groups were sacrificed. In order to confirm the systemic osteopenia in rats, a dual-energy X-ray absorptiometry (DXA) was performed. For the evaluation of bone density, digital radiographs were taken. The grey level of the bone adjacent to implant was measured using image software and the bone density was calculated at six points on both sides of the implant. RESULTS: Densitometry measurements of the femur confirmed systemic bone mass loss in the OVX group. Individualized bone analyses of different regions surrounding the implant showed a significantly lower radiographic bone density (P < 0.05) in the cancellous region of the OVX group (77.48 +/- 23.39 grey levels) when compared with the CTL and SHAM groups (91.61 +/- 32.10 and 102.57 +/- 32.50 grey levels, respectively). CONCLUSIONS: The present study showed a decrease of the radiographic bone density in the cancellous region of bone around titanium implants placed 8 weeks before ovariectomy in rats.

Absorptiometry, Photon↗
PubMed2006

Comparison between jaw bone augmentation by means of a stiff occlusive titanium membrane or an autologous hip graft: a retrospective clinical assessment.

OBJECTIVES: Patients in need of bone augmentation procedures can be treated with a traditional hip graft or by neogenesis under a stiff occlusive titanium membrane, custom-fit on the basis of CT-scan data. MATERIAL AND METHODS: Eighteen patients treated by means of a hip graft (H) were compared with 11 patients using a full titanium membrane (M) for the rehabilitation of upper jaws. In the H group, 17 patients (62 implants) in the anterior region (Ha) and 14 patients (23 implants) in the posterior region (Hp) were included. In the M group, nine patients (30 implants) in the anterior region (Ma) and seven patients (16 implants) in the posterior region (Mp) were included. RESULTS: In group Ha, the CFR was 13.3% after 14 years compared with group Ma where the CFR was 17.4% after 9 years. In group Hp, the CFR was 22.8% after 16 years compared with group Mp where the CFR was 23.4% after 6 years. The marginal bone loss for group Ha after 20 years was 2.7 mm, for group Ma it was not even 1 mm after 9 years; for group Hp, it was 2.5 mm after 15 years compared with less than 1 mm after 3 years in group Mp. CONCLUSIONS: The success rate of alveolar ridge augmentation therapy is lower than in a classical approach. These augmentation procedures, however, show acceptable results. The titanium membrane augmentation leads to less marginal bone loss probably because neo-formed bone has a better chance to adapt its mineralization to occlusal forces encountered. This technique could offer improvement if membrane exposure can be avoided.

Adult↗
PubMed2007

Profiling of bacterial flora in crevices around titanium orthodontic anchor plates.

OBJECTIVES: The aims of this study were to characterize the microflora in crevices around titanium orthodontic anchor plates using anaerobic culture and molecular biological techniques for bacterial identification, and to compare the microbial composition between crevices around anchor plates and gingival crevices. MATERIAL AND METHODS: Samples from crevices around titanium anchor plates and healthy gingival crevices of 17 subjects (aged 20-29) were cultured anaerobically, and isolated bacteria were identified by 16S rRNA sequencing. RESULTS: The average logarithm colony-forming units/ml were 6.84, 7.51 and 8.88 in healthy anchor plate crevices, inflamed anchor plate crevices and healthy gingival crevices, respectively, indicating that the bacterial density of anchor plate crevices was lower than that of healthy gingival crevices. Of 184 strains isolated from healthy anchor plate crevices of seven subjects, 108 (59%) were anaerobic bacteria, while 73 (40%) were facultative bacteria. Predominant isolates were Gram-negative rods, such as Campylobacter (12%), Fusobacterium (10%) and Selenomonas (10%), and Gram-positive facultative bacteria, such as Actinomyces (17%) and Streptococcus (8.2%). Of 133 strains isolated from inflamed anchor plate crevices of three subjects, 110 (83%) were anaerobic bacteria, while predominant isolates were Gram-negative rods, such as Prevotella (47%), Fusobacterium (33%) and Campylobacter (16%). On the other hand, of 146 strains isolated from healthy gingival crevices of seven subjects, 98 (67%) were facultative bacteria, while 45 (31%) were anaerobic bacteria. Predominant isolates were Gram-positive facultative bacteria, such as Actinomyces (37%) and Streptococcus (20%). CONCLUSIONS: These results suggest that the environment in crevices around titanium orthodontic anchor plates is anaerobic and supportive of anaerobic growth of bacteria, which may trigger inflammation in the tissue around the plates.

Actinomyces↗
PubMed2007

Decontamination of rough titanium surfaces with diode lasers: microbiological findings on in vivo grown biofilms.

OBJECTIVES: The bactericidal efficacy of diode lasers has already been demonstrated in vitro. We investigated the reduction of aerobe bacteria - colonizing rough titanium samples in biofilms intraorally grown - by diode lasers of different wave lengths. MATERIAL AND METHODS: Twenty-two volunteers participated in the trial. They were fitted for 10 days with custom-made intraoral plastic splints carrying titanium sleeves. A part of the sleeves was then irradiated with diode lasers in different modes. The other part remained non-irradiated and served as control. Directly after irradiation, the sleeves were swabbed and the gained bacteria were first examined microscopically and then were cultured under aerobic conditions. RESULTS: The bacteria in the controls and in the treated samples were quantified. A comparison with the controls revealed a marked overall reduction of bacterial colonization in all irradiated sleeves. Continuous irradiation for 20 s reduced bacteria counts by 99.67% at 810 nm and 99.58% at 980 nm. Repeating the 20 s exposure five times reduced counts by 99.98% at 810 nm and by 99.39% at 980 nm. A 98.86% reduction was seen after irradiation in pulsed mode. A further analysis in respect of different isolated bacteria revealed that the streptococci group was reduced by 99.29-99.99%, while the staphylococci group was reduced to a lesser extent in the range 94.67-99.99%. CONCLUSION: The results are of clinical relevance. In comparison with the mean bacterial counts of the untreated samples, all irradiation programs studied in this investigation reduced mean bacterial colonization in a biofilm on intraoral rough titanium surfaces by more than 98%. The actual extent of reduction was dependent on the bacteria species as well as on the irradiation mode.

Bacteria, Aerobic↗
PubMed1986

A clinical evaluation of fixed-bridge restorations supported by the combination of teeth and osseointegrated titanium implants.

The present paper reports on the result of the use of osseointegrated titanium fixtures and teeth as combined abutments for fixed-bridge restorations in 10 partially dentate patients. In these patients, the remaining teeth were too few or too unfavourably distributed in the jaws to serve as sole abutments for fixed bridgework. Titanium fixtures ad modum Brånemark were therefore implanted in suitable positions and used as abutments in combination with the remaining teeth. Evaluations at periods of 6 to 30 months postoperatively revealed good clinical results. Some tissue reactions, however, were also observed, indicating the presence of certain clinically significant differences in the functional behaviour of tooth abutments and titanium fixture abutments. These reactions and differences are discussed.

Adult↗
PubMed1992

Clinical, immunological and bacteriological evaluation of adverse reactions to skin-penetrating titanium implants in the head and neck region.

Between 1977 and October 1989, 445 patients have been treated with bone-anchored skin-penetrating titanium implants for anchorage of facial prostheses or bone-conducting hearing aids, at the Ear, Nose and Throat Department at Sahlgren's Hospital in Gothenburg. The majority of patients had no adverse skin reactions, while a few patients were responsible for the majority of the adverse reactions. The aim of our study was to analyse differences between these groups. We started a clinical study on 9 patients with a clinical history of adverse skin reactions around the titanium implants and 9 patients without adverse skin reactions were used as controls. None of the patients had delayed hypersensitivity to titanium. Microbiological analyses showed that when there was clinical irritation, Staphylococcus aureus could be isolated.

Adolescent↗
PubMed1988

Comparison of bone reactions to coated tricalcium phosphate and pure titanium dental implants in the canine iliac crest.

Titanium and TCP-coated implants were compared after insertion in the canine iliac crest. Observation time was 14 wk. Evaluation included pull-out tests, energy dispersive X-ray analysis, and histologic examination of in situ, undemineralized implants. The TCP-coated implants were more firmly attached to bone than were the titanium implants. The calcium/phosphorus ratios around the titanium implants were higher than around the TCP-coated implants. Both types of implants were closely surrounded by bone after a 14-wk implantation.

Animals↗
PubMed1997

Coating of titanium alloy with soluble laminin-5 promotes cell attachment and hemidesmosome assembly in gingival epithelial cells: potential application to dental implants.

The formation of a biological seal around the transmucosal portion of dental implants may be crucial for the long-term success of these therapies. Data to date suggest that the gingival epithelium attaches to dental implants through the formation of hemidesmosomes. Biochemical and genetic data indicate that the laminin isoform, laminin-5, a component of basement membranes, plays a crucial role in the assembly and maintenance of hemidesmosomes. We report the use of soluble laminin-5 as a biological coating of titanium-alloy to promote cell attachment of the gingival epithelial cell line, IHGK. Monoclonal antibodies reactive with laminin-5 depleted the coating solution of all cell attachment activity and blocked cell attachment to laminin-5-coated disks. Immunodepletion with antibodies to fibronectin had no effect. Finally, we demonstrate that IHGK cells assembled hemidesmosomes within 24 h of attachment to laminin-5-coated titanium alloy but not to the titanium alloy alone. These results suggest that soluble laminin-5 may have clinical applications as a dental implant coating to promote the formation of a biological seal.

Alloys↗
PubMed2001

Application of oxygen ion implantation to titanium surfaces: effects on surface characteristics, corrosion resistance, and bone response.

BACKGROUND: The surface oxide layer of titanium plays a decisive role in determining biocompatibility. However, there are some reports demonstrating that the natural oxide film may not be sufficiently protective in the aggressive biologic environment. PURPOSE: The goal of this study was to examine the effectiveness of a thick oxide layer on corrosion resistance in vitro and the bone formation around titanium implants in vivo. MATERIALS AND METHODS: A plasma source ion implantation (PSII) method was used to increase the thickness of the surface oxide layer. Several instruments were employed to confirm the surface properties before and after the surface modification. Potentiodynamic polarization measurements in a phosphate-buffered saline (PBS) solution were carried out to investigate corrosion resistance in vitro. Bone formation around this surface-modified specimen was examined in a rabbit model and assessed in histomorphometry. RESULTS: Improved corrosion resistance was demonstrated by the potentiodynamic polarization measurements. Light microscopic histomorphometry showed that all implants were in contact with bone and had some proportion of bone within the threads at 4 weeks; however, there were no significant differences compared with as-machined controls. CONCLUSIONS: The results indicate that in spite of improved corrosion resistance in vitro, a thick oxide layer fabricated with the PSII method does not influence early bone formation around titanium implants in vivo.

Animals↗
PubMed2002

Bone reactions to oxidized titanium implants with electrochemical anion sulphuric acid and phosphoric acid incorporation.

BACKGROUND: The importance of the surface properties of implants for a successful osseointegration has been emphasized. It is generally known that bone response to implant surfaces is considerably related to the various surface properties. PURPOSE: The purpose of this study was to investigate bone tissue reactions to multifactorial biocompatibility of the surface oxide of electrochemically oxidized titanium implants. The ultimate objective was to improve surface quality, resulting in enhancement of clinical outcomes of osseointegrated implants. MATERIALS AND METHODS: Three different surface types of commercially pure titanium (c.p. Ti) implants were prepared. Turned implants were used for controls and test implants were prepared by the micro arc oxidation (MAO) method, either in sulphuric acid (S implants) or in phosphoric acid (P implants). Implants were inserted in the femur and tibia of 10 mature New Zealand White rabbits. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. The follow-up time was 6 weeks. RESULTS: The mean peak values of the removal torque showed significant differences between control and test S implants (p =.022) but showed no significant differences between control and test P implants (p =.195) or between test S and test P implants (p =.457). In addition, the histomorphometric comparisons of the bone-to-metal contact around entire implants demonstrated 186% increase in S implants (p =.028) and 232% increase in P implants (p =.028) compared with the paired control groups. Quantification of the bone area in the threads did not show any significant differences. CONCLUSIONS: The present results suggest that the primary mode of action in strong bone response to S implants is mechanical interlocking, and to P implants, it is biochemical interaction. It is possible that the phosphate groups in the titanium oxide of P implants provide potential chemical bonding sites for calcium ions and hydroxyapatite of the bone matrix during biologic mineralization. key words: bone responses, histomorphometry, oxidized implants, removal torque test, surface oxide properties

Animals↗
PubMed2002

Reconstruction of the anterior maxilla with platelet gel, autogenous bone, and titanium mesh: a case report.

BACKGROUND: Reconstruction of defects in the anterior part of the maxilla to enable implant placement is a challenging treatment. Recent studies have suggested that the use of autogenous platelet gel may contribute to improved healing of bone grafts. PURPOSE: A case is presented in which particulated autogenous bone, platelet gel, and a titanium mesh were used for alveolar bone reconstruction of the anterior maxilla prior to implant placement. MATERIALS AND METHODS: Corticocancellous bone from the iliac crest was mixed with a preparation of autogenous platelet gel (platelet-rich plasma, thrombin, and calcium chloride) and placed against a titanium mesh fixed to the bone of the palate in a patient with severe resorption of the anterior maxilla. After 4.5 months of healing the mesh was removed and titanium implants were placed. A prolonged healing period of 8 months was allowed before healing abutments were placed and a fixed dental bridge was fabricated. RESULTS: Healing was uneventful, and the anterior maxilla had increased in height and width during the initial healing. All implants became integrated and have been supporting a fixed dental bridge for over 3 years with no dramatic dimensional changes of the graft. CONCLUSIONS: This case demonstrates that particulated autogenous bone and platelet gel may be used for reconstruction of the anterior maxilla. Autogenous growth factors in the gel possibly contributed to the positive outcome. Controlled clinical studies are needed to evaluate the effect of using platelet-rich plasma.

Adult↗
PubMed2005

Cast titanium overlay denture for a geriatric patient with a reduced vertical dimension.

An older patient reporting to the dental surgery for his/her dental treatment is becoming a common occurrence. Improved oral hygiene has meant that teeth are retained for a longer time, along with the potential problems of attrition, decreased vertical dimension, temporomandibular joint discomfort/strain, and poor aesthetics. The case in question is that of a 65-year-old male patient who had severe attrition in the lower arch, temporomandibular joint pain and reduced vertical dimension. The maxillary arch had previously been restored with a fixed partial prosthesis. For restoration of the lower teeth, a removable cast titanium overlay denture was fabricated incorporating an increased vertical dimension. Porcelain facings were placed to restore the aesthetics of the anterior teeth. The titanium was cast in a semi-automatic electric arc, pressure type casting machine. A titanium overlay denture with porcelain facing on the anterior teeth may provide a means of restoring a patient's concerns regarding aesthetics and function.

Aged↗
PubMed1999

Changes in root canal morphology in simulated curved canals over-instrumented with a variety of stainless steel and nickel titanium files.

The purpose of this project was to observe the amount of apical and mid-curve transportation produced by a range of nickel titanium (NiTi), titanium alloy and stainless steel (SS) files. Tests were carried out in simulated curved root canals produced in epoxy resin blocks. Seven commercially available file types were tested using sizes 15 to 40. Instrumentation was carried out to 1 mm beyond the apex. Changes in canal dimensions were measured at 10x magnification under a shadowgraph. There were substantial differences in the amount and the pattern of apical and mid-curve transportation produced. The amount of transportation increased with each subsequent size of file. Under the same conditions, nickel titanium files produced significantly less transportation than stainless steel files. The least apical transportation was obtained with the NiTi Mity Turbo and the most by the SS K file and SS Hedstrom file. The least mid-curve transportation was produced by the NiTi Mity Turbo and the most by the SS Hedstrom file.

Alloys↗
PubMed2000

Titanium carbide nanocrystals in circumstellar environments.

Meteorites contain micrometer-sized graphite grains with embedded titanium carbide grains. Although isotopic analysis identifies asymptotic giant branch stars as the birth sites of these grains, there is no direct observational identification of these grains in astronomical sources. We report that infrared wavelength spectra of gas-phase titanium carbide nanocrystals derived in the laboratory show a prominent feature at a wavelength of 20.1 micrometers, which compares well to a similar feature in observed spectra of postasymptotic giant branch stars. It is concluded that titanium carbide forms during a short (approximately 100 years) phase of catastrophic mass loss (>0.001 solar masses per year) in dying, low-mass stars.

Astronomical Phenomena↗
PubMed2003

Fixation of distal radius fractures using AO titanium volar distal radius plate.

This study is to assess the effectiveness and outcome of the AO titanium volar distal radius plate (Synthes) in the treatment of peri-articular volar rim fractures of the distal radius. It was conducted on 22 patients with distal radius fractures who underwent open reduction, internal fixation using the AO titanium volar distal radius plate between July 1998 and December 1999 at the Changi General Hospital. The radiographs of the patients were analysed upon fracture union and assessment of wrist function was done using Gartland and Werley criteria. There were four extra-articular AO Type A2(1) and A3(3): the remaining 18 intra-articular fractures consisted of AO B3(2), AO C1(11), AO C2(2) and AO C3(3). The average follow-up period was 12.6 months (range 7-23). Radiological review showed bone healing in 21 patients (95.5%) and good articular congruity for all intra-articular fractures with less than 2 mm step-off. Three patients defaulted follow-up. Complications were few with one wound infection, one tendon rupture and three neuropraxia of the superficial radial nerve. Wrist function was excellent in three patients, good in 12 and fair in four. The AO titanium plate with its distal buttressing ability is an effective treatment modality in patients with distal radius fractures involving the peri-articular volar rim.

Adult↗
PubMedDate not supplied

Titanium and glass-ionomer cement as ossicular replacement materials: biocompatibility results after implantation in the rabbit.

The middle ear poses unique challenges when finding suitable materials for ossicular reconstruction, primarily because of its link to the external environment via the eustachian tube, which leads to a greater potential for exposure to infectious agents. In this animal study, the biocompatibilities of titanium and glass-ionomer cement were assessed in the middle ear of the rabbit after being implanted as total ossicular replacement prostheses (TORPs) or as free pins. Animals were sacrificed after 28, 84, 168, 336, or 504 days or 2 years, and a cutting saw technique was used to prepare slides for light microscopy. Slides were examined for mucosal coverage and any sign of foreign body reaction. Both materials showed good acceptance in the middle ear. After 28 days, the TORPs were covered by middle ear mucosa. As expected, it took a longer time (up to 504 days) to cover the free implants. An interesting finding was the growth of new bone on both the surface of the titanium implants and the glass-ionomer prostheses. The results of this animal study indicate that both titanium and glass-ionomer cement are favorable materials for ossicular replacement prostheses.

Animals↗
PubMed2001

The human stratum corneum layer: an effective barrier against dermal uptake of different forms of topically applied micronised titanium dioxide.

Electron microscopy visualisation and light microscopic investigations of three different application forms of titanium dioxide proved that neither surface characteristics, particle size nor shape of the micronised titanium dioxide result in any dermal absorption of this substance: Micronised titanium dioxide is solely deposited on the outermost surface of the stratum corneum and cannot be detected in deeper stratum corneum layers, the human epidermis and dermis.

Administration, Topical↗
PubMed1988

Titanium balanitis with phimosis.

We report the 2nd case of titanium balanitis reported in the world literature. Clinically the patient presented with phimosis: histologically the titanium was surrounded by a mixed granulomatous inflammatory reaction. Topical titanium preparations may lead to phimosis and therefore we thought it important to bring this potential iatrogenic complication to further notice.

Balanitis↗