Search

Purpose: This study aimed to investigate the effect of collagen cross-link deficiency on collagen fiber formation around an implant and its effect on the osseointegration process., Methods: Wistar rats were fed 0.1% beta-aminopropionitrile (BAPN) dissolved in water to induce collagen cross-link deficiency. Custom-made mini-implants with machined surfaces were placed proximal to the tibia. At 1, 2, and 4 weeks postoperatively, the bone area around the implant, bone-implant contact ratio, osteoclast/osteocyte activity, and osseointegration strength were evaluated using histological and immunohistochemical analyses and biomechanical tests., Results: Long-term disturbance of collagen cross-link formation in the BAPN group resulted in faster collagen fiber maturation than that in controls, with a defective collagen structure, low bone formation quantity, and low bone-implant contact values. Deficiency of collagen cross-links resulted in increased bone resorption and decreased osteocyte activity., Conclusions: Collagen cross-linking is important for the formation of the collagen matrix, and their deficiency may impair bone activity around implants, affecting the osseointegration process.

Pectin and chitosan are natural polysaccharides obtained from fruit peels and exoskeletons of crustaceans and insects. They are safe for usage in food products and are renewable and biocompatible. They have further applications as wound dressings, body fat reduction, tissue engineering, and auxiliary agents in drug delivery systems. The healing process is usually long and painful. Adding a new material such as a pectin-chitosan composite to the implant surface or body would create unique biological responses to accelerate healing and delivery of target-specific medication at the implant site. The present study utilized the electrospraying process to create pectin-chitosan polyelectrolyte composite (PCPC) coatings with various ratios of 1:1, 2:1, 1:2, 1:3, and 3:1 on commercially pure titanium substrates. By means of FESEM, AFM, wettability, cross-cut adhesion, and microhardness were assessed the PCPC coatings' physical and mechanical properties. Subsequently, the antibacterial properties of the coating composite were assessed. AFM analysis revealed higher surface roughness for group 5 and homogenous coating for group 1. Group 3 showed the lowest water contact angle of 66.7° and all PCPC coatings had significantly higher Vickers hardness values compared to the control uncoated CpTi samples. Groups 3 and 4 showed the best adhesion of the PCPC to the titanium substrates. Groups 3, 4, and 5 showed antibacterial properties with a high zone of inhibitions compared to the control. The PCPC coating's characteristics can be significantly impacted by using certain pectin-chitosan ratios. Groups 3 (1:2) and 4 (1:3) showed remarkable morphological and mechanical properties with better surface roughness, greater surface strength, improved hydrophilicity, improved adhesion to the substrate surface, and additionally demonstrated significant antibacterial properties. According to the accomplished in vitro study outcomes, these particular PCPC ratios can be considered as an efficient coating for titanium dental implants., (© 2023. The Author(s).)

This study investigated whether a 6-Watt ultraviolet C-lamp was capable of producing photofunctionalization on commercial implants during a medium observation term of 8 weeks. A total of 20 implants were inserted in 5 New Zealand rabbits, with each animal receiving 2 implants per tibia (one photofunctionalized and one untreated), according to a previously established randomization sequence. All implants were inserted by a single surgeon following the manufacturer's instructions. Histological analysis was performed by an evaluator who was blinded to the treatment condition. After 8 weeks of healing, the 2 groups showed no statistically significant differences in terms of bone-to-implant contact. Compared to control implants, the photofunctionalized implants showed improved wettability and more homogenous results. Within the limits of the present study, the use of this 6-W ultraviolet C-lamp, for an irradiation time of 15 minutes at a distance of 15 cm, did not improve the percentages of bone-to-implant contact in rabbits at an osseointegration time of 8 weeks.

Purpose: The purpose of this study was to investigate the effect of a biologically active dental implant surface (treated with sandblasting and acid etching [SLA] followed by immersion in simulated body fluid [SBF]) on osseointegration., Materials and Methods: We randomly divided 9 healthy adult male beagles (aged 8 months; body weight, 12 kg) into 3 groups: machined, SLA, and SLA-biomineralization (SLA-Bio). Six pure titanium implants (diameter of 3.5 mm and length of 8 mm) were used in the mandible of each dog after observation of the surface morphology, as well as analysis of the composition of the surface elements by scanning electron microscopy-energy dispersive x-ray spectroscopy. At 4, 8, and 12 weeks after implantation, animals were euthanized to collect the mandibles so that we could perform the removal torque test to evaluate the implant stability in bone and histomorphometry to analyze the implant-bone osseointegration., Results: Scanning electron microscopy results showed that uniformly distributed sponge-like structures were found on the SLA-treated surface and an apatite layer was observed on the SLA-SBF-treated surface (SLA-Bio group). In the energy dispersive x-ray spectroscopy analysis, the elements titanium, oxygen, carbon, calcium, and phosphorus were found on the surfaces of the SLA-Bio group, whereas titanium was the only element found in the other groups. The removal torque test showed that the peak removal torque values of the 3 groups increased gradually with the passage of time, and the peak removal torque values of the SLA-Bio group were significantly higher than those of the other groups (P < .01) at 4, 8, and 12 weeks after implantation. Histomorphometric analysis showed that osseointegration was being enabled more rapidly in the SLA-Bio group, as well as that the mineral apposition rate and percentage of bone-to-implant contact of the SLA-Bio group were higher than those of the remaining groups at 4, 8, and 12 weeks after implantation (P < .01)., Conclusions: Treating titanium implants with SLA-SBF can improve osseointegration as well as increase the interfacial shear strength., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

The nanotechnology field plays an important role in the improvement of dental implant surfaces. However, the different techniques used to coat these implants with nanostructured materials can differently affect cells, biomolecules and even ions at the nano scale level. The aim of this study is to evaluate and compare the structural, biomechanical and histological characterization of nano titania films produced by either modified laser or dip coating techniques on commercially pure titanium implant fixtures. Grade II commercially pure titanium rectangular samples measuring 35 × 12 × 0.25 mm length, width and thickness, respectively were coated with titania films using a modified laser deposition technique as the experimental group, while the control group was dip-coated with titania film. The crystallinity, surface roughness, histological feature, microstructures and removal torque values were investigated and compared between the groups. Compared with dip coating technique, the modified laser technique provided a higher quality thin coating film, with improved surface roughness values. For in vivo examinations, forty coated screw-designed dental implants were inserted into the tibia of 20 white New Zealand rabbits' bone. Biomechanical and histological evaluations were performed after 2 and 4 weeks of implantation. The histological findings showed a variation in the bone response around coated implants done with different coating techniques and different healing intervals. Modified laser-coated samples revealed a significant improvement in structure, surface roughness values, bone integration and bond strength at the bone-implant interface than dip-coated samples. Thus, this technique can be an alternative for coating titanium dental implants.

Background: Despite the existence of several studies validating the use of narrow diameter implants, most of them are based on pure Ti alloys. There is few clinical evidence of the success of TiZr narrow diameter implants (TiZr NDIs) regarding survival rate (SR) and marginal bone loss (MLB)., Purpose: The aim of this review was to systematically assess SR, as well as MBL of TiZr NDIs compared to commercially pure titanium narrow diameter implants (cpTi NDIs)., Material and Methods: The search was conducted in Medline/PubMed, Cochrane, Scopus, and Embase databases (year 2000 to November 2016). Cohort studies and randomized trials were included., Results: Six clinical studies from the 3453 articles initially identified met the inclusion criteria. There were no statistically significant differences in SR when TiZr NDIs and cpTi NDIs were compared in the 1-year follow up (P = .5), or when comparing TiZr NDIs placed in posterior and anterior regions. There was no difference between groups regarding 1-year SR: -0.01 (95% CI, -0.05-0.03) and MLB: -0.01 mm (95% CI: -0.14-0.12)., Conclusion: It can be concluded that TiZr NDIs present similar success rates and peri-implant bone resorption to cpTi NDIs., (© 2017 Wiley Periodicals, Inc.)

Objectives: Titanium-zirconium (TiZr) has been proposed as a mechanically stronger alternative to commercially pure titanium for oral and orthopaedic implants. However, not much is known on the osseointegration kinetics of TiZr surfaces. In this study, we aimed to identify the genetic response of bone around TiZr implants compared to pure Ti., Material and Methods: Microtextured and hydrophilic TiZr implants (tests) and cpTi implants grade IV (controls) were placed in the tibia of 30 New Zealand white rabbits. At 2, 4 and 12 weeks, the implants were subjected to removal torque test (RTQ). The expression of a panel of genes involved in the process of osseointegration was measured in the bone around the test and control implants by means of quantitative real-time polymerase chain reaction (PCR) and compared to the control samples., Results: The controls yielded statistically significant higher RTQ at 4 weeks, but the RTQ of the tests had a larger increase between 4 and 12 weeks, when both groups reached similar values. The gene expression analysis showed that all selected markers for bone formation, bone remodelling and cytokines were significantly upregulated around TiZr implants after 2 weeks. After 4 weeks of healing, two bone formation markers were significantly more expressed in the test samples, while at 12 weeks, the expression of all genes was similar in the two groups., Conclusions: TiZr implants showed comparable biomechanical outcomes to cpTi up to 12 weeks of healing. However, at early healing stages, they showed a significant upregulation of osteogenesis and osteoclastogenesis markers., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: This study evaluated the osseointegration of commercially pure titanium (Ti) grade-2 (G2) and Ti-6Al-4V alloy (G5) implants with the same geometry and surface treatment., Materials and Methods: Thirty-six dental implants with a grit-blasted acid-etched surface were used (n = 18, each). Two implants, one per group, were installed in each subject, in the radius diaphysis (n = 18 beagle dogs), with interchanged fixture position (proximal-distal) between animals for a balanced number of devices per group and time in vivo (1, 3, and 6 weeks)., Results: Similar topographical parameters between G2 and G5 were observed for average surface roughness, root mean square, developed surface ratio, maximum height of surface, and density of summits. Removal torque was significantly higher for G5 than for G2. No differences were observed for bone-to-implant contact and bone-area-fraction occupancy. Removal torque significantly increased with time for both groups. At 1 week, new bone formation in direct contact with the implant surface and osteogenic tissue migration was observed with an increase in woven bone formation at 3 weeks followed by the onset of lamellar bone formation at 6 weeks., Conclusion: Although both surfaces were biocompatible and osteoconductive, increased removal torque was observed for Ti-6Al-4V compared with commercially pure Ti implants.

The development of Ti alloys to manufacture dental implants has emerged in recent years due to the increased failure of commercially pure titanium (cpTi) implants. Thus, this study reviews existing information about the mechanical, chemical, electrochemical, and biological properties of the main Ti alloys developed over the past few years to provide scientific evidence in favor of using Ti-based alloys as alternative to cpTi. Ti alloys may be considered viable substitutes in the fabrication of dental implants. Such evidence is given by the enhanced properties of alloys, such as a low elastic modulus, high tensile strength, satisfactory biocompatibility, and good corrosion and wear resistances. In addition, Ti alloys may be modified at the structural, chemical, and thermomechanical levels, which allows the development of materials in accordance with the demands of several situations encountered in clinical practice. Although several in vitro studies have established the superiority of Ti alloys over cpTi, mainly in terms of their mechanical properties, there is no scientific evidence that supports the total replacement of this material in vivo. This review demonstrates the superiority of β-type alloys. However, it is evident that in vivo studies are encouraged to test new alloys to consolidate their use as substitutes for cpTi., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Purpose: To evaluate the bone response to grade IV commercially pure titanium (G4) relative to Ti-6Al-4V (G5)., Materials and Methods: Implant surface topography was characterized by optical interferometry and scanning electron microscopy (SEM). Thirty-six implants (Signo Vinces, n = 18 per group) were installed in the radius of 18 dogs. The animals were killed at 1, 3, and 6 weeks, resulting in 6 implants per group and time in vivo for bone morphology, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) evaluation., Results: SEM depicted a more uniform topography of G4 than G5. Surfaces were statistically homogeneous for Sa, Sq, and Sdr. At 1 week, new bone formation was observed within the healing connective tissue in contact with the implant surface. At 3 weeks, new bone in direct contact with the implant surface was observed at all bone regions. At 6 weeks, the healing chambers filled with woven bone depicted an onset of replacement by lamellar bone. No significant effect of substrate was detected. Time presented an effect on BIC and BAFO (P < 0.001)., Conclusion: Both titanium substrates were biocompatible and osseoconductive at the bone tissue level.

Purpose: The purpose of this study was to visualize the mode and impact of force transmission in narrowdiameter implants with different implant-abutment designs and material properties and to quantify the displacement of the abutment., Materials and Methods: Narrow-diameter implants from two manufacturers were examined: Astra 3.0-mm-diameter implants (Astra OsseoSpeed TX; n = 2) and Straumann Bone Level implants with a 3.3-mm diameter made of commercially pure titanium (cpTi) Gr. 4 (n = 2) and 3.3-mm TiZr-alloy (n = 2; Bone Level, Straumann) under incremental force application using synchrotron radiography (absorption and inline x-ray phase-contrast) and tomography., Results: During loading (250 N), Astra 3.0 and Bone Level 3.3- mm implants showed a deformation of the outer implant shoulder of 61.75 to 95 μm independent of the implant body material; the inner implant diameter showed a deformation of 71.25 to 109.25 μm. A deformation of the implant shoulder persisted after the removal of the load (range, 42.75 to 104.5 μm). An angulated intrusion of the abutment (maximum, 140 μm) into the implant body during load application was demonstrated; this spatial displacement persisted after removal of the load., Conclusion: This study demonstrated a deformation of the implant shoulder and displacement of the abutment during load application in narrow-diameter implants.

Objective: To analyze marginal bone loss (MBL) and clinical parameters around narrow-diameter implants (NDIs - 3.3 mm) made of titanium/zirconium alloy (TiZr) in comparison with commercially pure titanium (cpTi) installed in the molar region of the mandible after 1 year in function., Materials and Methods: Ten patients participated in the study. A TiZr and a cpTi NDI were randomly installed in contralateral molar sites of the mandible of each patient in a split-mouth design. Eight weeks after healing, all metal-ceramic single crowns were adapted to the implants and patients were enrolled in a plaque control program. MBL at the mesial and distal aspects of the implants were evaluated by comparing periapical radiographs taken immediately after prosthesis installation (T1) and 1 year after loading (T2). Clinical probing depth, bleeding on probing, suppuration, visible plaque and implant mobility were evaluated to determine implant success and survival rates., Results: Mean MBL at the interproximal aspects of TiZr implant sites was 0.32 ± 0.27 mm, while at cpTi implant sites mean MBL was 0.35 ± 0.24 mm (P = 0.60). Both TiZr and cpTi NDIs presented 100% implant survival and success rates, with no significant differences in the clinical parameters studied (P > 0.05)., Conclusion: TiZr and cpTi NDIs presented similar outcomes after 1 year in function in the molar region of the mandible. The results suggest that TiZr and cpTi NDIs may be equally used to support single crowns in the posterior area of the mouth. However, further studies with longer follow-up periods are necessary to confirm these findings., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The objects of this research are commercially pure titanium surfaces, with multifunctional behavior, obtained through a chemical treatment and biological functionalization. The explored surfaces are of interest for dental implants, in contact with bone, where several simultaneous and synergistic actions are needed, in order to get a fast and effective osseointegration. The here described modified surfaces present a layer of titanium oxide, thicker than the native one, with a multi-scale surface topography (a surface roughness on the nano scale, which can be overlapped to a micro or macro roughness of the substrate) and a high density of OH groups, that increase surface wettability, induce a bioactive behavior (hydroxyapatite precipitation in simulated body fluid) and make possible the grafting of biomolecules (alkaline phosphatase, ALP, in the present research). The surface oxide is an efficient barrier against corrosion, with passive behavior both with and without application of an external voltage., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Titanium and its alloys form a thin amorphous protective surface oxide when exposed to an oxygen environment. The properties of this oxide layer are thought to be responsible for titanium and its alloys biocompatibility, chemical inertness, and corrosion resistance. Surface oxide crystallinity and pore size are regarded to be two of the more important properties in establishing successful osseointegration. Anodization is an electrochemical method of surface modification used for colorization marking and improved bioactivity on orthopedic and dental titanium implants. Research on titanium anodization using sulphuric acid has been reported in the literature as being primarily conducted in molarity levels 3 M and less using either galvanostatic or potentiostatic methods. A wide range of pore diameters ranging from a few nanometers up to 10 μm have been shown to form in sulfuric acid electrolytes using the potentiostatic and galvanostatic methods. Nano sized pores have been shown to be beneficial for bone cell attachment and proliferation. The purpose of the present research was to investigate oxide crystallinity and pore formation during titanium anodization using a pulsed DC waveform in a series of sulfuric acid electrolytes ranging from 0.5 to 12 M. Anodizing titanium in increasing sulfuric acid molarities showed a trend of increasing transformations of the amorphous natural forming oxide to the crystalline phases of anatase and rutile. The pulsed DC waveform was shown to produce pores with a size range from ≤0.01 to 1 μm(2). The pore size distributions produced may be beneficial for bone cell attachment and proliferation.

Introduction: Titanium (Ti) is widely accepted as a biomaterial for orthopaedic and dental implants, primarily due to its capacity to integrate directly into the bone and its superior corrosion resistance. It has been suggested that titanium–zirconium alloy (TiZr), with 13–17% of zirconium, has better mechanical properties than pure Ti, but there are very few published studies assessing the suitability of TiZr for high-load- bearing implants. This study aimed to compare the mechanical properties and microstructures of TiZr and commercially pure titanium (Ti). Methodology: Pure Ti and TiZr alloy discs were prepared and subjected to characterisation by nanoindentation, electron dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD). Results: The TiZr alloy was found to have significantly lower elastic modulus value (p

The indigenously produced pure titanium dental implants are economical and useful for common human use in India. The aim of this study is to test the biocompatibility of the indigenously produced pure titanium dental implant material obtained from the Defense Metallurgical Research Laboratory, Hyderabad, India, and the Institute of Nuclear Medicine and Allied Science, Delhi, India. An experimental study in rabbits was done to study the amount of ordered bone formation around the screw and cylinder type of indigenously produced pure titanium metal implant specimens. The experimental animals were killed at 4, 6, 8, 12, and 16 weeks from the date of implantation. The histopathological examination of the animals killed at 16 weeks demonstrates the presence of osteoblastic cell proliferation and early ordered bone formation toward the implant site, indicating signs of osseointegration of both screw- and cylinder-type indigenously produced pure titanium specimens.

Background: Surface chemistry of dental implant plays an important role in osseointegration. Heat treatment might alter surface chemistry and result in different biological response. The aim of this study was to investigate the roles of heat treatment of H2O2/HCl-treated Ti implants in cell attachment, proliferation and osteoblastic differentiation., Material/methods: Sandblasted, dual acid-etched and H2O2/HCl heat-treated discs were set as the control group and sandblasted, dual acid-etched H2O2/HCl-treated discs were the test group. Both groups' discs were sent for surface characterization. MC3T3-E1 cells were seeded on these 2 groups' discs for 3 hours to 14 days, and then cell attachment, cell proliferation and cell differentiation were evaluated., Results: Scanning electron microscope analysis revealed that the titanium discs in the 2 groups shared the same surface topography, while x-ray diffraction examination showed an anatase layer in the control group and titanium hydride diffractions in the test group. The cell attachment of the test group was equivalent to that of the control group. Cell proliferation was slightly stimulated at all time points in the control group, but the alkaline phosphatase (ALP) activity and osteocalcin (OC) production increased significantly in the test group compared with those in the control group at every time point investigated (p<0.05 or p<0.01). Moreover, the osteoblastic differentiation-related genes AKP-2, osteopontin (OPN) and OC were greatly up-regulated in the test group (p<0.05 or p<0.01)., Conclusions: The results implied that surface chemistry played an important role in cell response, and H2O2/HCl etched titanium surface without subsequent heat treatment might improve osseointegration response.

Background: Little is known about the mechanisms of bacterial interaction with implant materials in the oral cavity. Other surface characteristics, in addition to surface roughness, seem to be extremely important in relation to plaque formation. Different adhesion affinities of bacteria were reported for different materials. Anatase is a nanoparticle that can be applied to titanium surfaces as a coating. The anatase coating gives special characteristics to the implant surface, including some genetic effects on osteoblasts. In this study, the antibacterial effect of anatase is investigated. The aim of this study is to characterize the percentages of surfaces covered by bacteria on commercially pure (cp) titanium and anatase-coated healing screws., Methods: Ten patients participated in this study. The protocol of the study was approved by the ethics committee of the University of Chieti-Pescara. A total of 20 healing screws (10 test and 10 control screws) were used in the study. The control screws were made of cp titanium, whereas the test screws were coated with anatase. Cleaning procedures and agents for chemical plaque control were not applied to the healing screws for the complete duration of the test period. After 7 days, all healing screws were removed, substituted, and processed under scanning electron microscopy for evaluation of the portions of the surfaces covered by bacteria., Results: The supracrestal screw surfaces covered by bacteria on test specimens were not significantly lower than those of control screws (P = 0.174). The subcrestal screw surfaces and threads covered by bacteria on test specimens were significantly lower than those of control screws, and P values were 0.001 and 0.000, respectively., Conclusion: Results show that anatase could be a suitable material for coating implant abutments, with a low colonization potential.

Objectives: Acid etching is a popular method to texture the surface of dental implants. During etching, the titanium oxide protective layer is dissolved and small native hydrogen ions diffuse into the unprotected implant surface. They enrich the implant surface with hydrogen and precipitate into titanium hydride (TiH). The aim of this study was to measure the concentration of TiH at the implant surface and the total concentration of Hydrogen at five commercially available implant systems, made of either commercially pure (cp) titanium or titanium alloy., Material and Methods: X-Ray diffraction (XRD) was conducted on each implant system to determine the compounds present at the implant surface. Following a TiH(2)/Ti calibration curve, the concentration of TiH was determined. Concentration of hydrogen in the implants was measured by the inert gas fusion thermal conductivity/infrared detection method., Results: XRD data showed that TiH was present on all cp titanium implants but not on the alloyed implants. TiH concentration varied between 5% and 37%. Hydrogen concentration varied between 43 and 108 ppm, no difference in uptake was found between the cp titanium and alloyed implants. Low solubility of hydrogen in alpha-titanium is responsible for precipitation into TiH. Stronger etching conditions led to higher concentration of TiH2-x., Conclusion: High solubility of hydrogen in the beta-phase of the alloy is preventing hydrogen from precipitating into TiH. All implants, even those lacking TiH at the surface, were enriched with hydrogen. In all implants, hydrogen concentration was within the normative limit of 130 ppm.

This paper introduces how TiO2 film was prepared on pure titanium by anodic oxidation. Surface morphology and composition of the oxide film were analyzed by SEM coupled with EDAX. The deposition ability of hydroxyapatite of the anodized titanium in simulated body fluid (SBF) at 37 degrees C was evaluated. The results indicated that the oxide film was rough and honeycomb holes, connecting with each other, could be found on the surface. The holes with the diameter of 1-2 microm were distributed uniformly, which was typical for anodic oxidation. After alkaline treatment, hydroxyapatite deposition on the oxidized specimens in SBF was improved significantly.

Purpose: To compare the bone responses to a pure titanium machined implant surface and one that has been modified by laser etching and microarc oxidation., Materials and Methods: Forty-eight threaded implants with a machined surface were manufactured from rods of commercially pure titanium. The control group consisted of 24 implants with a machined surface. The test group consisted of 24 machined-surface implants that were modified by laser etching and treated by microarc oxidation in an electrolyte solution containing Ca2+ and PO43- ions. The implants were analyzed by energy-dispersive x-ray and scanning electron microscopy. Next, the two types of implants were inserted in the tibiae of 12 New Zealand White rabbits; one of the two tibiae received two control implants and the opposite side received two test implants. After 2, 4, and 6 weeks, the rabbits were sacrificed. Prior to sacrifice, all rabbits were injected with fluorescent-labeled achromycin and calcein. Samples were cut and ground for histomorphologic observation, and the mineralization appositional rate and the osseointegration index were measured and analyzed., Results: Proportional spacing craters were found with a diameter of 100 microm and a depth of 80 to 100 microm at intervals of 100 microm around the test surface, and a porous titanium dioxide coating on the surface with pores of 1 to 5 micro in diameter was also produced. Carbon, oxygen, calcium, and phosphonium were detected by electronic probe. The ratio of calcium to phosphonium was 1.418, and the crystal structure of x-ray diffractive patterns indicated pure anatase phases. Compared with the control samples, the mineralization ratio and the osseointegration index of the bone around the test implants were higher (P = .00)., Conclusions: The porous titanium dioxide coating produced by laser etching and microarc oxidation treatment improved the bone response versus that seen around machined titanium implants and enhanced the bone formation rate. It was concluded that the surface chemistry and topography, either separately or together, play an important role in the bone response to implants.

Purpose: This study evaluated the effect of external hexagon height and commonly applied surface treatments on the fatigue life of titanium dental implants., Materials and Methods: Electropolished commercially pure titanium dental implants (seven implants per group) with three different external hexagon heights (0.6, 1.2, and 1.8 mm) and implants with the highest external hexagon height (1.8 mm) and different surface treatments (electropolishing, grit blasting with aluminium oxide, and acid etching with sulfuric acid) were tested to evaluate their mechanical fatigue life. To do so, 10-Hz triangular flexural load cycles were applied at 37 degrees C in artificial saliva, and the number of load cycles until implant fracture was determined. Tolerances of the hexagon/abutment fit and implant surface roughness were analyzed by scanning electron microscopy and light interferometry. Transmission electron microscopy and electron diffraction analyses of titanium hydrides were performed., Results: First, the fatigue life of implants with the highest hexagon (8,683 +/- 978 load cycles) was more than double that of the implants with the shortest hexagons (3,654 +/- 789 load cycles) (P < .02). Second, the grit-blasted implants had the longest fatigue life of the tested materials (21,393 +/- 2,356 load cycles), which was significantly greater than that of the other surfaces (P < .001). The compressive surface residual stresses induced when blasting titanium are responsible for this superior mechanical response. Third, precipitation of titanium hydrides in grain boundaries of titanium caused by hydrogen adsorption from the acid solution deteriorates the fatigue life of acid-etched titanium dental implants. These implants had the shortest fatigue life (P < .05)., Conclusions: The fatigue life of threaded root-form dental implants varies with the height of the external hexagon and/or the surface treatment of the implant. An external hexagon height of 1.8 mm and/or a blasting treatment appear to significantly increase fatigue life of dental implants.

To gain insight on the early biological response to commercial pure titanium (cpTi), the surface properties of cpTi implants retrieved from rat bone were examined by X-ray photoelectron spectroscopy (XPS). To this end, semi-cylindrical bullets, 1.1 mm in diameter and 3.5 mm in length, were implanted into the femurs of Wistar rats and then retrieved after either 3 hours or 7 days. Regardless of implantation interval, elements of Ti, O, C, and N were observed on the retrieved implants and that the thickness of the adsorbed film (mainly protein) was estimated to be about 2.5 nm. Small amounts of both Ca and P were also detected, whereby the Ca/P atomic ratios after 3 hours and 7 days were very small compared to that of hydroxyapatite. Furthermore, no correlation was found between the Ca and P distributions in the element maps. In conclusion, no calcium phosphate compounds were formed on the implant in vivo after 7 days.

Purpose: The objective of this study was to assess the influence of a fluoride medium with different pHs on the corrosion resistance of three commercially pure titanium-based dental implant commercial brands, under scanning electron microscopy (SEM) and EDS., Materials and Methods: Forty-two dental implants, from three commercial brands, were used. Five years of regular use of mouth rinsing, with NaF 1500 ppm content and two different pHs, were simulated by immersing the specimens into that medium for 184 hours., Results: SEM and EDS analyses demonstrated no evidence of corrosion on the specimens' surfaces after being submitted to fluoride ions or incorporation of fluoride ions to the set surface., Conclusion: It was possible to conclude that both the fluoride concentration and the pH of the solutions did not exert any influence upon implant corrosion resistance.

To improve integration between implants and biological tissues, this study compared bone sialoprotein (BSP) as a surface-coating material against the major organic and inorganic components of bone, collagen type I and hydroxyapatite (TICER). The expression of osteocalcin, osteonectin and transforming growth factor ss was evaluated using immunohistochemical staining procedures. The distribution patterns of osteoblasts on the surface of pure titanium with a smooth machined surface and a rough surface (TICER) were determined by image processing using confocal laser scanning microscopy. The results compared to uncoated control materials showed that, at all times investigated, the number of cells on the surface of the TICER and pure titanium samples differed significantly (P<0.1), demonstrating the superiority of TICER over pure titanium in this respect. For pure titanium implants, collagen-precoated surfaces were not beneficial for the attachment of bone-derived cells with the exception of day 3 in vitro (P<0.01). BSP-precoated implant surfaces displayed non-significantly higher numbers of settled cells. BSP-precoated implant surfaces were beneficial for osteoinduction as revealed by osteocalcin and osteonectin expression. BSP precoating of the rough TICER implant surface enhanced the osteoinductive effect much more than did collagen precoating. These results contribute to the consideration of at least two distinct pathways of osseointegration.

The aim of this study was to evaluate the bone response to an oxidized titanium implant (Ox) and a calcium-incorporated oxidized titanium implant (Ca). A blasted titanium implant (Bl) was used as control. The implants were topographically characterized using an optical interferometer and placed: one in each distal femoral metaphysis and two in each proximal tibial metaphysis in rabbits. The rabbits were killed 12 weeks after implant insertion, and the implants and their surrounding tissues were removed en bloc for histomorphometrical evaluations. Topographical evaluation revealed three different surfaces: average height deviation (S(a), microm) values for Ca:Ox:Bl implants were 0.3:0.6:0.9, developed surface area ratios (%) 17:44:31, number of summits per microm(2) 208:136:118, and core fluid retention index values 1.33:1.33:1.38. The mean percentages of bone contact to the implants placed in the tibia (Ca:Ox:Bl) were 47:30:34 and to the implants placed in the femur (Ca:Ox) 32:20. The mean percentages of surrounding bone area for the implants placed in the tibia were 40:47:37 and for the implants placed in the femur 43:46. A significant increase in bone contact was found for smooth (S(a) <0.5 microm) but more densely peaked calcium-incorporated oxidized implants when compared to slightly rougher (S(a)=0.5-1.0 microm) oxidized or blasted implants.

This study compared the vertical misfit of 3-unit implant-supported nickel-chromium (Ni-Cr) and cobalt-chromium (Co-Cr) alloy and commercially pure titanium (cpTi) frameworks after casting as 1 piece, after sectioning and laser welding, and after simulated porcelain firings. The results on the tightened side showed no statistically significant differences. On the opposite side, statistically significant differences were found for Co-Cr alloy (118.64 microm [SD: 91.48] to 39.90 microm [SD: 27.13]) and cpTi (118.56 microm [51.35] to 27.87 microm [12.71]) when comparing 1-piece to laser-welded frameworks. With both sides tightened, only Co-Cr alloy showed statistically significant differences after laser welding. Ni-Cr alloy showed the lowest misfit values, though the differences were not statistically significantly different. Simulated porcelain firings revealed no significant differences.

Many surface modification strategies are currently of interest in improving integration of implants to bone. An in vitro precoating of a bone-like mineralized layer of immobilized collagen on the implant surface is a potentially valuable approach to improve host acceptance of the implant. The goal of this investigation was to develop a method to precoat in vitro a bone-like mineralized collagen layer on a pure titanium dental implant surface. The study was conducted on acid-etched and nonetched surfaces of screw implants. Initially, a procedure was standardized to self-assemble collagen from a collagen solution. In subsequent experiments, the implant was also placed inside the solution, and after 3 days, collagen was found to be coated on the implant surface. Mineralization of the collagen gel as well as collagen coating on the implant was carried out by calcium phosphate precipitation from a mineralizing solution of calcium chloride containing polyvinyl phosphonic acid and polyaspartic acid, which served as polyanionic additives to help disperse the precipitation and template mineral nucleation. The implant was kept in the mineralizing solution and maintained for 2 weeks in an incubator at 37 degrees C with a phosphate vapor phase generated from a vial containing dihydrogen ammonium phosphate in the incubator. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analysis confirmed the coated layer to be a biomimetic bone-like mineralized type 1 collagen. Initial studies using osteoblast-like cells indicated cellular attachment on the modified surface. The method appears to be a promising way to generate in vitro a bone-like layer on the implant surface.

Objectives: The purpose of this study was to measure and compare the passive fit and vertical fit of one-piece cast frameworks fabricated with three different materials: commercially pure titanium (CP Ti), cobalt-chromium alloy (Co-Cr) and nickel-chromium-titanium alloy (Ni-Cr-Ti)., Methods: Fifteen frameworks simulating bars for fixed prosthesis in a model with five implants were fabricated and arranged into three different groups according to the material used. The fit of the framework abutment interface was measured using an optical microscope, when only one screw was manually tightened at a terminal abutment (passive fit) or when all framework screws were tightened to 10 N cm torque (vertical fit). Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney tests (alpha=0.05)., Results: Mean and standard deviation values of passive fit and vertical fit are presented, respectively: CP Ti [88 (74) microm and 22 (9) microm], Co-Cr [229 (184) microm and 66 (35) microm], Ni-Cr-Ti [200 (175) microm and 32 (24) microm]. There were no significant differences between passive fit of Co-Cr and Ni-Cr-Ti frameworks (p=0.313), but both alloys were statistically different from CP Ti (p<0.001 and 0.035, respectively), which showed the best results. As for vertical fit, CP Ti and Ni-Cr-Ti alloy were statistically similar (p=0.162) and they presented a better vertical fit than Co-Cr alloy (p<0.001)., Conclusions: Within the limitations of this study, it was possible to conclude that one-piece cast frameworks resulted in unacceptable passive fit and vertical fit, no matter which material had been used to fabricate them. However, the best results were obtained using CP Ti followed by Ni-Cr-Ti and Co-Cr alloys, respectively.

Purpose: Using sandblast, double acid-etching and H(2)O(2)/HCl solution treatment to establish a new implant surface, and to analyze the surface's morphology., Methods: After being polished, sandblasted, cleaned, the titanium specimens were divided into six groups, i.e.A to F group. The specimens of group A were treated with low concentration of HF/HNO(3) solution, Group B was treated with low concentration of HF/HNO(3) solution and then H(2)SO(4)/HCl solution, Group C was treated after Group B and further with H(2)O(2)/HCl solution at 80degrees centigrade for 30 minutes, and subsequently heated at 400degrees centigrade for 1 hour. Group D was treated with high concentration of HF/HNO(3) solution, Group E was treated after Group D and then H(2)SO(4)/HCl solution, Group F was treated after E group and further with H(2)O(2)/HCl solution at 80degrees centigrade for 30 minutes, and subsequenty heated at 400degrees centigrade for 1 hour., Results: The titanium surface sandblasted and ultrasonically cleaned exhibited a great deal of particles. The titanium plates treated with low concentration of HF/HNO(3) solution still had some particles, but there were much nano-holes on the titanium surface. The titanium plates treated with high concentration of HF/HNO(3) solution had no particles on the surface, but showed much micron-holes on the titanium surface. The titanium plates treated with H(2)SO(4)/HCl solution after HF/HNO(3) solution etching had all particles removed and got multilevel holes on the surface.The last H(2)O(2)/HCl method produced an anatase titania gel layer on the specimen surface., Conclusion: By altering the concentration of HF/HNO(3) solution, we could make different sizes of apertures on the titanium surface. Double acid-etching can remove all sandblasting particles embedded in titanium surfaces and form multilevel holes. The H(2)O(2)/HCl method can turn the rough non- crystallographic TiO(2) layer into the anatase titania gel layer.

Background: The failure of osseointegration in oral rehabilitation has gained importance in current literature and in clinical practice. The integration of titanium dental implants in alveolar bone has been partly ascribed to the biocompatibility of the implant surface oxide layer. The aim of this investigation was to analyze the surface topography and composition of failed titanium dental implants in order to determine possible causes of failure., Methods: Twenty-one commercially pure titanium (cpTi) implants were retrieved from 16 patients (mean age of 50.33 +/- 11.81 years). Fourteen implants were retrieved before loading (early failures), six after loading (late failures), and one because of mandibular canal damage. The failure criterion was lack of osseointegration characterized as dental implant mobility. Two unused implants were used as a control group. All implant surfaces were examined by scanning electron microscopy (SEM) and energy-dispersive spectrometer x-ray (EDS) to element analysis. Evaluations were performed on several locations of the same implant., Results: SEM showed that the surface of all retrieved implants consisted of different degrees of organic residues, appearing mainly as dark stains. The surface topography presented as grooves and ridges along the machined surface similar to control group. Overall, foreign elements such as carbon, oxygen, sodium, calcium, silicon, and aluminum were detected in failed implants. The implants from control group presented no macroscopic contamination and clear signs of titanium., Conclusion: These preliminary results do not suggest any material-related cause for implant failures, although different element composition was assessed between failed implants and control implants.

Purpose: The purpose of this study was to compare the marginal bone loss (MBL), complications, and 12-year survival rates of commercially pure titanium (cpTi) and hydroxyapatite (HA)-coated implants placed in the maxilla., Materials and Methods: The study group consisted of 120 patients (77 women, 43 men) treated from 1988 to 1997. A total of 388 implants (156 cpTi and 232 HA-coated) were placed in the maxilla. There were 126 immediate (32.5%) and 262 (67.5%) nonimmediate implants. Patients were evaluated annually. Mean follow-up was 60 +/- 32.3 months. MBL was measured on radiographs using the implant threads as the dimensional reference. MBL, complications, and 12-year survival and success rates were correlated with implant coating, time of implantation, implant dimensions, and position in arch., Results: Total mean MBL was 1.07 +/- 2.16 mm. MBL was significantly lower with cpTi implants (0.55 +/- 1.04 mm) compared to HA-coated implants (1.51 +/- 2.71 mm) (P < .001). No statistical difference in regard to MBL was found between immediate and nonimmediate implants (0.86 +/- 1.8 mm vs 1.16 +/- 2.3 mm). The total 12-year survival rate was 91.4%. HA-coated implants had a significantly higher 12-year survival rate than cpTi implants (93.2% vs 89%; P < .03). Nonimmediate implants had a significantly higher failure rate (8.2%) than the immediate implants (1.3%) (P < .009). No correlation was found between type of implant coating and late implant failure., Discussion: Immediate implants can serve as a predictable option, providing higher survival and success rates. HA-coated implants tended to fail less during the surgical phase, but had higher mean MBL compared to cpTi implants., Conclusions: HA-coated implants had greater MBL than cpTi implants but a higher 12-year survival rate. Immediate implants had a lower failure rate than the nonimmediate implants in this study population.

Statement of Problem: For implant-supported prostheses, passive fit is critical for the success of rehabilitation, especially when alternative materials are used., Purpose: The purpose of this study was to compare interfacial fit of implant-supported prostheses cast in titanium to those cast in gold alloy., Material and Methods: Five 3-unit fixed partial dentures were fabricated in gold alloy (Degudent U) as 1-piece castings, and 5 others were similarly cast in commercially pure titanium (Grade 1). The interfacial gaps between the prostheses and the abutments were evaluated with an optical microscope, before and after electroerosion. Readings were made with both screws tightened (10 N.cm torque), and with only 1 side tightened, so as to also evaluate the passive fit of the prostheses. Data were compared statistically by 2-way analysis of variance and the post hoc Tukey multiple range test (alpha=.05)., Results: Before electroerosion, the interfacial gaps for the 1-piece prostheses were significantly smaller (P<.001) in the gold alloy group when the screws were tightened (Au=12.6 +/- 3.0 microm, compared to Ti=30.1 +/- 6.4 microm). When the side opposite the tightened side was analyzed, there was no significant difference between the gold alloy and titanium groups (Au=69.2 +/- 24.9 microm and Ti=94.2 +/- 39.6 microm). The electroerosion procedure significantly (P<.001) reduced the gaps at the interfaces for both groups under all conditions. Comparison between groups after electroerosion did not present significant differences when the side opposite the tightened side was analyzed, but the gold alloy group showed better fit when the tightened side was analyzed (12.8 +/- 1.4 microm for gold alloy; 29.6 +/- 4.4 microm for titanium) and when both screws were tightened (5.4 +/- 2.3 microm for gold alloy; 16.1 +/- 5.5 microm for titanium)., Conclusions: Cast titanium prostheses, despite showing larger interfacial gaps between the prosthesis and abutment than those obtained with gold alloy, had improved fit after being subjected to electroerosion.

In order to study the character of periodontal ligament cells (PDLCs) attaching on commercially pure titanium (cpTi) by morphology and metrology on the early stage (24 h), 1 x 10(5)/ml PDLCs in 2 ml culture medium were seeded on cpTi discs fixed in 24-well culture plates. Morphology of cell attachment was observed by contrast phase microscope, scanning electron microscope (SEM) and fluroscence microscopy. Cell adhesion was analyzed by MTT at 0.5, 1, 2, 4 h respectively. PDLCs could attach and spread on cpTi discs. SEM showed that PDLCs had pseudopod-like protuberance. PDLCs showed different attaching phases and reached saturation in cell number at 2 h. It was concluded that PDLCs had good biocompatibility with cpTi, and showed a regular and dynamic pattern in the process of attaching to cpTi.

Objective: To study the cell behavior of periodontal ligament cells (PDLCs) cultured on commercially pure titanium (cpTi) by cell morphology, cell counting and osteoclin (OC) immunofluorescent staining., Methods: 1 x 10(5)/ml PDLCs in 2 ml culture medium were seeded on cpTi discs fixed in 24-well culture plates. Morphological study of cell attachment was observed by scanning electron microscope (SEM) and fluorescence microscopy. Cell adhesion was analyzed by MTT at 0.5, 1, 2, 4 hours respectively. OC was directly observed by immunofluorescent staining., Results: PDLCs could attach and spread on cpTi discs. SEM showed that PDLCs had pseudopod-like protuberance. PDLCs showed different attaching phase and reached saturation in cell number at the early stage. The cells and ECM could express OC 7 days later., Conclusion: PDLCs show a regular, dynamic pattern in early stage and they can keep proliferating and differentiating on CpTi in vitro. It was indicated that the biological function of PDLCs around dental implant should be reconsidered.

The aim of this study was to investigate the effects of hydroxyapatite-coated and commercially pure titanium oral implants on nerve conduction. Isolated rat sciatic nerves were placed between two suction electrodes in a bath containing a tyrode solution. The implants were brought into intimate contact with the nerves and evoked compound action potentials (cAPs) were recorded before and after contact with the implants. The commercially pure titanium implants did not cause any change in cAPs. A gradual reduction in cAPs was observed for hydroxyapatite-coated implants. However, this reduction was < 50% after an application time of 120 min. Recovery of the cAPs in this group was recorded after approximately 60 min. We conclude that, although intimate contact with hydroxyapatite-coated implants leads to a reduction in cAPs in nerves in vitro, neither this surface nor a commercially pure titanium surface leads to irreversible neurotoxic effects.

It is well known that the osseointegration of the commercially pure titanium (c.p. Ti) dental implant is improved when the metal is shot blasted in order to increase its surface roughness. This roughness is colonised by bone, which improves implant fixation. However, shot blasting also changes the chemical composition of the implant surface because some shot particles remain adhered on the metal. The c.p. Ti surfaces shot blasted with different materials and sizes of shot particles were tested in order to determine their topographical features (surface roughness, real surface area and the percentage of surface covered by the adhered shot particles) and electrochemical behaviour (open circuit potential, electrochemical impedance spectroscopy and cyclic polarisation). The results demonstrate that the increased surface area of the material because of the increasing surface roughness is not the only cause for differences found in the electrochemical behaviour and corrosion resistance of the blasted c.p. Ti. Among other possible causes, those differences may be attributed to the compressive residual surface stresses induced by shot blasting. All the materials tested have an adequate corrosion and electrochemical behaviour in terms of its possible use as dental implant material.

Purpose: The purpose of this pilot study was to evaluate the histologic and mechanical healing process in dental implants under the action of pulsed electromagnetic field (PEMF)., Materials and Methods: Forty-eight commercially pure implant fixtures were implanted in tibiae metaphysis of 12 New Zealand white rabbits divided into experimental (PEMF) and control groups. A PEMF with pulse width of 85 microseconds and a pulse frequency of 20 Mc was applied for 30 minutes per day. The animals were killed 21 and 42 days after implantation. The mechanical tests were performed in all animals and bone biopsies were prepared for decalcified sections analysis., Results: Mechanical tests did not show significant differences between the groups (P > 0.05); however, statistically significant differences were observed over time (P < 0.0001). Similar histologic features were achieved for both groups., Conclusions: These results suggest that PEMF stimulation does not improve the bone-healing process around commercially pure dental implants.

Purpose: The purpose of this study was to use three-dimensional finite element analysis to analyze stress distribution patterns in Re-Implant implants made of commercially pure titanium (cpTi) and yttrium-partially stabilized zirconia (YPSZ)., Materials and Methods: Two three-dimensional finite element analysis models of a maxillary incisor with Re-Implant implants were made, surrounded by cortical and cancellous bone. A porcelain-fused-to-metal crown for the cpTi implant and a ceramic crown for the YPSZ implant were modeled. Stress levels were calculated according to the von Mises criteria., Results: Higher stresses were observed at the area where the implant entered the bone. Stresses were higher at the facial and lingual surfaces than the proximal ones. In cortical bone and at the junction of cortical and cancellous bone, stress distribution presented a pattern of alternating higher (4.0 to 5.0 MPa) and lower (1.3 to 2.0 MPa) stress areas. Higher stresses were found at the apical third of the implant-to-bone junction as well., Conclusion: Re-Implant implants presented a pattern of low, well-distributed stresses along the entire implant-to-bone interface. YPSZ implants had very similar stress distribution to cpTi implants and may be viable esthetic alternatives, especially in maxillary anterior regions.

Objective: To study the oxide film of pure titanium implant material treated by anodic oxidation and to learn the effect of anodic oxidation on it., Methods: Six titanium sheets, which were ground, polished and pretreated, were treated by anodic oxidation at 10 v, 24 v or 40 v for 10 minutes and at 24 v for 10 minutes, 40 minutes or 2 hours. The microstructures and the corrosive-resistance of oxide films were studied by means of X-ray diffraction and electro-chemical corrosion., Results: The results of X-ray diffraction showed that the titanic peaks of 2.55 and 2.34 inverted as potential went up. Not many disorderly peaks of titanium oxide were found. And all the peaks of 2.55 and 2.34, 1.25 and 1.23, 1.72 and 1.47 did the same when time went on. Disorderly peaks of titanium oxide first appeared more and then fewer. The open loop potential of the oxide film treated by anodic oxidation moved positively, and polarized current was a 100'th of that of natural oxide film., Conclusions: The oxide film with a certain color and crystallinity could be controlled by the potential and time. The corrosive-resistance of the oxide film is greatly improved by means of anodic oxidation. It will be the next study how to utilize and adjust the rule of titanium crystal corrosion.

Objective: The aim of this investigation was to evaluate the influence of surface roughness of pure titanium on adhesion of bacterium., Methods: A total of six edentulous volunteers with healthy oral mucosa participated in an in vivo study. Four kinds of pure Titanium testing pieces with different surfaces were fixed in the polished surface of upper complete dentures and the other in the tissue surface of the dentures. After 6-month wearing the dentures, the amount and species of bacterium adhered on pure Titanium were examined., Results: (1) Individual difference had a significant influence on amount of bacterium adhered on pure Titanium, but had no relation to species of bacterium according to Gram's staining. (2) To the same patient, with the increase of roughness, bacterium adhered on samples improved in amount (P < 0.01), but remained the same in composition. Wrinkly samples collected more bacterium than plane samples and exhibited G- coccus beside G+ coccus. Comparing two samples with same roughness, the one with roughness on the tissue surface of the denture collected less bacterium than that on the polished surface (P < 0.01), and predominantly presented G- rod bacterium and coccus, which was completely different to that on the polished surface., Conclusion: From the perspective of benefit to periodontal tissue, plane surface should be adopted when framework of pure Titanium is made, and polishing of the prosthesis after being modified should be paid more attention, especially on the tissue surface.

Formation of a calcium phosphate layer was studied on the surfaces of plasma-sprayed hydroxyapatite (PSHA) and sandblasted commercially pure (cp) titanium in simulated body fluid with ion concentrations similar to those of human blood plasma. The PSHA surface induced the formation of calcium phosphate surface layers, while the precipitation of calcium phosphate on sandblasted cp titanium was not detected. Histologic evaluation of in vivo tests demonstrated that implants with a PSHA coating enabled the growth of bone tissue into gaps with a depth of up to 1 mm without significant formation of intermediate fibrous tissue. In comparison to sandblasted cp titanium, implants with PSHA coating exhibited greater tolerance to unfavorable conditions during healing, such as gaps at the interface or primary instability of the implant. In the case of good primary stability of the implant, filling of the gap with fibrous tissue was observed for sandblasted cp titanium implants over the greater part of the surface of gaps with a depth of 0.3 mm. Direct contact of cp titanium implants with bone was achieved only when the press-fit implantation model was used.

Clinical data indicate different medium and long-term outcomes of endosseous implants for different implant configurations and in particular implant surfaces. The present study compares 2 very similar implant systems but with different surface characteristics in a split-mouth-randomized design. The Astra-Tech (A) system (Astra-Tech AB, Mölndal, Sweden) consisted of selftapping TiO2-blasted screw-shaped implants made of commercially pure titanium, and the Brånemark (B) System (Nobel Biocare, Gothenburg, Sweden) comprised selftapping Mark II implants with machined surface irregularities. Throughout the 2-years' observation period, no significant differences could be found concerning probing depths, presence of plaque or change in marginal bone level. A statistically significant difference in location of the marginal bone level in relation to the shoulder of the implant was found in favor of the A system both at baseline and after 2 years. Cumulative success rates of 100% (A) and 97.7% (B) were not statistically different. From a prosthetic point of view, more soldering points were needed for A compared to B to reach clinical acceptable fit. More years of observation are needed to compare the fate of the soft and hard tissues surrounding two different implant surfaces.

Manufacturers use six different titanium-based biomaterials to fabricate dental implants. Each of these materials, including four grades of commercially pure titanium and two titanium alloys, has distinct mechanical and physical properties. Clinicians should recognize these differences for optimal treatment planning and patient care.

A technique that achieves different pure titanium surfaces depending on acid concentration and exposure time is described. It is possible to obtain, with the same chemical treatment, both large pits and small rugosities. This technique may have interesting applications in oral implants.

Implant dentistry has evolved to the point that standard implant osseointegration is predictable. This is attributed in part to the advancements in material sciences that have led toward improvements in implant surface technology and characteristics. Nonetheless, there remain several cases where implant therapy fails (specifically at early time points), most commonly attributed to factors affecting bone metabolism. Among these patients, smokers are known to have impaired bone metabolism and thus be subject to higher risks of early implant failure and/or late complications related to the stability of the peri-implant bone and mucosal tissues. Notably, however, emerging data have unveiled other critical factors affecting osseointegration, namely, those related to the metabolism of bone tissues. The aim of this review is to shed light on the effects of implant-related factors, like implant surface or titanium particle release; surgical-related factors, like osseodensification or implanted biomaterials; various drugs, like selective serotonin reuptake inhibitors, proton pump inhibitors, anti-hypertensives, nonsteroidal anti-inflammatory medication, and statins, and host-related factors, like smoking, diet, and metabolic syndrome on bone metabolism, and aseptic peri-implant bone loss. Despite the infectious nature of peri-implant biological complications, these factors must be surveyed for the effective prevention and management of peri-implantitis., (© 2023 The Authors. Periodontology 2000 published by John Wiley & Sons Ltd.)

Objective: The cosmetically good coverage of skull defects is a challenge in neurosurgical clinics. In addition, the skull treated with implants and the underlying structures must remain radiologically assessable. In this examination, the postoperative courses of patients after implantation of CranioTop is described. Digital x-ray, computed tomography, and magnetic resonance images after implantation of CranioTop were evaluated with regard to their assessability., Materials and Methods: Between 2018 and 2020, 23 titanium cranioplasties (CranioTop) were implanted to 21 patients. The intraoperative handling, the accuracy of fit, the healing process, the cosmetic result and the physical condition of the patients were examined. In addition, digital x-rays, magnetic resonance imaging, and computed tomography scans of the cranium supplied with CranioTop were examined., Results: The evaluation showed good to very good results regarding patients' satisfaction. There were no severe complications; thirteen patients found the cosmetic result very good; 8 patients assessed the cosmetic result as good. Because of the low thickness and density of the CranioTop plastic there was only low formation of radial stripe artifacts (streaking) and susceptibility artifacts. The assessment of digital x-ray, computed tomography, and magnetic resonance imaging images is possible after implantation of CranioTop., Conclusion: The patients treated with CranioTop showed a high level of satisfaction with regard to the cosmetic result and their physical condition. Furthermore, the cranium supplied with CranioTop remains well assessable in radiologic imaging with only slight limitations in magnetic resonance imaging., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

The purpose of this study was to determine which treatment of a large osseous defect adjacent to an endosseous dental implant would produce the greatest regeneration of bone and degree of osseointegration: barrier membrane therapy plus demineralized freeze-dried bone allograft (DFDBA), membrane therapy alone, or no treatment. The current study histologically assessed changes in bone within the healed peri-implant osseous defect. In a split-mouth design, 6 implants were placed in edentulous mandibular ridges of 10 mongrel dogs after preparation of 6 cylindrical mid-crestal defects, 5 mm in depth, and 9.525 mm in diameter. An implant site was then prepared in the center of each defect to a depth of 5 mm beyond the apical extent of the defect. One mandibular quadrant received three commercially pure titanium (Ti) screw implants (3.75 x 10 mm), while the contralateral side received three hydroxyapatite (HA) coated root-form implants (3.3 x 10 mm). Consequently, the coronal 5 mm of each implant was surrounded by a circumferential defect approximately 3 mm wide and 5 mm deep. The three dental implants in each quadrant received either DFDBA (canine source) and an expanded polytetrafluoroethylene membrane (ePTFE), ePTFE membrane alone, or no treatment which served as the control. Clinically, the greatest increase in ridge height and width was seen with DFDBA/ePTFE. Histologically, statistically significant differences in defect osseointegration were seen between treatment groups (P < 0.0001: DFDBA/ePTFE > ePTFE alone > control). HA-coated implants had significantly greater osseointegration within the defect than Ti implants (P < 0.0001). Average trabeculation of newly formed bone in the defect after healing was significantly greater for HA-coated implants than for titanium (P < 0.0001), while the effect on trabeculation between treatments was not significantly different (P = 0.14). Finally, there were significantly less residual allograft particles in defect areas adjacent to HA-coated implants than Ti implants (P = 0.0355). The use of HA-coated implants in large size defects with DFDBA and ePTFE membranes produced significantly more osseointegration histologically than other treatment options and more than Ti implants with the same treatment combinations. The results of this study indicate that, although the implants appeared osseointegrated clinically after 4 months of healing, histologic data suggest that selection of both the implant type and the treatment modality is important in obtaining optimum osseointegration in large size defects.

Purpose: This report presents the preliminary results of a prospective multicenter study to evaluate the efficacy of a chemically etched pure titanium surface on screw-type dental implants., Material and Methods: The results of 147 implants placed in 75 patients were evaluated and followed for up to 3 years, using clinical and radiographic examinations. The implants were inserted to support single crowns, overdentures, and fixed prostheses, as dictated by the individual patient's need., Results: Of the 147 implants placed, 5 were lost and the remaining implants were followed throughout, to the end of the study period. Crestal bone levels adjacent to each implant were monitored and the amount of total bone loss was calculated. Clinically healthy peri-implant gingival tissues were observed on 95% of the implants, whereas 88.3% demonstrated no bleeding on probing and no recession during the follow-up period. According to the criteria used in this study, the total success rate was calculated to be 96.6%.

Statement of Problem: Implant survival depends on proper and timely oral hygiene maintenance, and a wide variety of oral prophylaxis procedures have been recommended and used on implant abutments., Purpose: This in vitro study compared the surface quality of both commercially pure titanium and titanium-alloy implant abutments, subjected to various hygiene methods and instruments with a standardized, clinically applicable scaling force., Material and Methods: Commercially pure titanium and titanium-alloy abutments were exposed to five oral hygiene methods; a gold-alloy-tipped scaler, a high-grade resin scaler, a graphite-reinforced scaler, an air-powder abrasive system, and a rubber cup with tin oxide slurry. A customized test device that simulated the scaling motion and allowed the application of a standard load at the tip of the scaler was used. Scanning electron photomicrographs (x200) of the pretreatment and treated surfaces were obtained and compared qualitatively., Results and Conclusions: No significant surface alteration was produced by the air abrasive system. All other hygiene methods either created significant surface alterations, left residual particles on the abutment surfaces, or both.