Titanium-zirconium Alloy Implants Research Articles

Investigation of Topographical Alterations in Titanium-Zirconium-Alloy Implant Threads following Er:YAG Irradiation.

The aim of the current experimental study was to comparatively assess the surface alterations in titanium and titanium-zirconium alloy implants in terms of thread pitch topography after irradiation with an Er:YAG laser, which is recommended in the literature for its sterilizing effect in the treatment of contaminated implant surfaces. Roxolid® and SLA® (Sand-blasted, Large-grit, Acid-etched) implants from Straumann® company with the same macro topography were investigated. The surface treatment was carried out using a wavelength of 2940 nm, 60 s irradiation time, a frequency of 10 Hz, and energies between 120 mJ and 250 mJ. The alterations were quantitatively analyzed by conducting roughness analysis via white light interferometry and qualitatively using SEM images. Roxolid® could particularly maintain its surface topography at a level of 160 mJ. At an energy level of 250 mJ, the surface properties of the pitch could be significantly altered for the first time. Compared to the Standard Plus dental implants studied, no distinct removal of the material from the surface was detected. The alloy properties of Roxolid® confirm the manufacturer's statement in terms of stability and could offer advantages in peri-implantitis management if decontamination has been selected. However, as a part of a respective strategy, smoothening of a Roxolid® implant surface requires a significantly higher energy level compared to SLA-Standard® dental implants.

Strength of titanium-zirconium alloy implants with a conical connection after implantoplasty

Statement of problemPeri-implantitis occurs around dental implants, and implantoplasty has been used to address this ongoing disease; however, the changes to the physical properties of an implant after implantoplasty have not been well documented. PurposeThe purpose of this in vitro study was to determine the effect of implantoplasty on fracture strength and the load required for plastic deformation after cyclic fatigue on dental implants. Material and methodsTwenty-six titanium/zirconium (TiZr) alloy implants (Roxolid Bone Level Implant; 4.1×10 mm) were embedded with 50% thread exposure and divided into 4 groups based on whether they had implantoplasty treatment by using different diamond rotary instruments and/or cyclic loading at 250 N for 2 million cycles: C0 (control, no cyclic loading), T0 (test, no cyclic loading), CM (control, cyclic loading), and TM (test, cyclic loading). After implantoplasty and/or cyclic loading, all implants underwent a load-to-failure test. The maximum fracture strength (FS) and load required for the onset of plastic deformation (PD) were recorded in Newtons. One-way ANOVA and nonparametric comparisons with control by using the Dunn and Wilcoxon method for joint ranking were used for statistical analysis. ResultsThe mean ±standard deviation FS for C0, CM, T0, and TM was 1465.2 ±86.4 N, 1480.7 ±64.1 N, 1299.3 ±123.8 N, and 1252.1 ±85.7 N, respectively. The mean ±standard deviation load for onset of PD for C0, CM, T0, and TM was 860.2 ±88.1 N, 797.0 ±130.5 N, 776.5 ±181.8 N, and 631.3 ±84.5 N, respectively. The TM group had a significantly lower FS and PD than the C0, CM, and T0 groups (P<.05) ConclusionsBoth fracture strength (FS) and the onset of plastic deformation (PD) were significantly reduced after a TiZr alloy implant received implantoplasty and cyclic loading.

A Pilot Study with Randomised Controlled Design Comparing TiZr Alloy Dental Implants to Ti Implants

ABSTRACTObjectivesEvidence on the clinical performance of recently introduced dental implants in titanium-zirconium alloy is sparse. The aim of the present pilot study with randomized controlled design is to compare changes in supporting structures around dental titanium-zirconium alloy implants to commercially pure titanium implants.Material and MethodsThe present material includes consecutive patients referred to a specialist clinic in Sweden. Two patient groups treated with dental implants in two different materials - titanium (Ti) and titanium-zirconium (TiZr) - were defined after block randomisation for smoking. In total, 40 implants installed in 21 patients were available for one-year follow-up. Marginal bone level, soft tissue height and width of keratinised mucosa were registered at baseline and at one-year follow-up.ResultsAt implant level, the test group (TiZr) yielded significant marginal bone loss (P < 0.001) after one year. Additionally, marginal bone loss after one year was significantly higher for TiZr implants (P < 0.001) as compared to traditional Ti implants. Soft tissue dimensions were stable throughout the evaluation time for both implant materials.ConclusionsOne-year results indicate more pronounced initial marginal bone loss for dental implants in titanium-zirconium alloy as compared to implants made of commercially pure titanium.

EVALUATION OF ARTIFACTS GENERATED BY TITANIUM, ZIRCONIUM, AND TITANIUM-ZIRCONIUM ALLOY DENTAL IMPLANTS IN MRI, CT, AND CBCT IMAGES: AN IN VITRO STUDY

<h3>Background</h3> Magnetic resonance imaging (MRI) or computed tomography/cone beam computed tomography (CT/CBCT) should be performed in implant therapy when the conventional image is not adequate or when more information is needed to improve the patient's treatment. Therefore, 3-D imaging may be required even when the implants are present in the field of view (FOV). Thus, determining the most suitable imaging technique and setting for each type of implant material will facilitate the radiologists ability to give the best care to the patient. <h3>Objective(s)</h3> The aim of this study was to assess the amount and structure of artifacts caused by titanium grade 4 and 5, zirconium, and titanium–zirconium alloy implants in MRI, CT, and CBCT with several acquisition protocols and to correlate the findings to the radiation dose given by 2 different CT machines and different CBCT exposure settings. <h3>Study Design</h3> Three phantoms were built by embedding titanium, zirconium, and titanium–zirconium alloy implants in ultrasound gel. MRI, CT, and CBCT images were acquired using multiple sequences and settings. For MRI, the artifact was described as the length of signal void beyond the limits of the implant. For CT and CBCT, the artifact was calculated by subtracting the gray level of the darkest pixel from the one of the lightest pixel. <h3>Results</h3> Titanium and titanium–zirconium alloy implants created extensive artifacts in MRI as a result of high susceptibility, whereas zirconium implants could be correctly depicted with only minor distortion artifacts. However, in CT and CBCT, titanium and titanium–zirconium alloy implants generated less severe artifacts than zirconium. <h3>Discussion/Conclusions</h3> MRI images were less affected by the artifacts from zirconium implants, whereas CT and CBCT images showed fewer artifacts from titanium and titanium–zirconium alloy implants. CBCT, especially at low dose settings, produced the least amount of radiation compared with high-resolution settings and 2 CT machines.

Assessment of signal-to-noise ratio and contrast-to-noise ratio in 3 T magnetic resonance imaging in the presence of zirconium, titanium, and titanium-zirconium alloy implants.

We quantitatively compared the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in T1 weighted imaging (WI) and T2 WI sequences in 3 Tesla (T) magnetic resonance imaging (MRI) using zirconium, titanium (grades 4 and 5), and titanium-zirconium alloy implants to evaluate the effect of implant type and imaging sequence. MRI was acquired using a 3 T magnet with a 16-channel head coil. Implants of each type were mounted in gel and scanned in axial, coronal, and sagittal planes using fast spin echo sequences in T1 WI (TR = 600, TE = 12 milliseconds) and T2 WI (TR = 3000, TE = 80 milliseconds) sequences. Data were transferred to Synapse 3-D software, and images were measured twice by an oral and maxillofacial radiologist blinded to the type of implants. Zirconium implants resulted in the lowest SNR and CNR values (P < .05). No significant differences were identified between titanium (grades 4 and 5) and titanium-zirconium implants. The T2 WI sequence had a significantly higher SNR and CNR than T1 WI. There was no difference in intraobserver agreement between T1 WI and T2 WI. CNR and SNR at 3 T MRI are dependent on implant type and imaging sequence. Titanium (grades 4 and 5) and titanium-zirconium implants and the T2 WI sequence produced higher SNR and CNR values.

Surface morphology and surface properties of Ti and TiZr implant materials

Objective: To investigate the effects of hydrophilic treatment on the surface morphology and surface properties of pure titanium and titanium-zirconium alloy implants, and to provide reference for the studies of implant surface modification. Methods: The pure titanium group, the hydrophilic pure titanium group, the titanium zirconium alloy group and the hydrophilic titanium-zirconium alloy group were prepared by sandblasting and acid-etching or hydrophilic sandblasting and acid-etching, (11 specimens in each group). The surface morphology and surface properties of four types of titanium specimens were analyzed by surface contact angle meter, scanning electron microscope (SEM), optical profilometer, atomic force microscope (AFM) and Raman spectrometer. Results: The surface contact angles of hydrophilic pure titanium and hydrophilic titanium-zirconium alloy were 1.6°±0.3° and 1.5°±0.2°, and the surface contact angles of pure titanium and titanium-zirconium alloy were 101.4°±4.6° and 96.2°±3.0°, respectively. SEM showed that the nano-protrusions on the surface of pure titanium and titanium-zirconium alloys were less or even absent, while the nano-protrusions on the surface of hydrophilic pure titanium and hydrophilic titanium-zirconium alloys were relatively more; the nano-protrusions on the surface of hydrophilic pure titanium surface were small and dense relatively, but the nano-protrusions of the hydrophilic titanium-zirconium alloy had large diameters and were dispersed relatively. The optical profiler and AFM showed that the surface roughness of hydrophilic pure titanium and hydrophilic titanium-zirconium alloy was significantly higher than that of pure titanium and titanium-zirconium alloy (P<0.05). Raman spectroscopy showed that only the amorphous TiO(2) was present on the surface of the pure titanium group, while the rutile TiO(2) characteristic peak was observed in the other three groups, but the lateral inhomogeneity was observed. After Raman shift 610 cm(-1), the Raman spectra of four groups were similar. Conclusions: Hydrophilic sandblasting and acid-etching treatment can improve the surface hydrophilicity and surface roughness of pure titanium and titanium zirconium alloy, and improve the surface properties of pure titanium and titanium zirconium alloy implants.

Evaluation of artifacts generated by titanium, zirconium, and titanium–zirconium alloy dental implants on MRI, CT, and CBCT images: A phantom study

The aim of this study was to assess artifacts generated by zirconium, titanium, and titanium-zirconium alloy implants on magnetic resonance imaging(MRI), computed tomography(CT), and cone beam computed tomography(CBCT) and to correlate the findings to the dose-area product and exposure factors on CT and CBCT. Three phantoms were built by embedding zirconium, titanium, and titanium-zirconium implants in ultrasound gel. MRI, CT, and CBCT images were acquired by using multiple sequences and settings. For MRI, "artifact" was described as the length of signal void beyond the limits of the implant. For CT and CBCT, "artifact" was calculated by subtracting the gray level of the darkest pixel from the level of the lightest pixel. On MRI, zirconium implants had minor distortion artifacts, whereas titanium and titanium-zirconium implants created extensive artifacts (P < .05). On CT and CBCT, artifacts were less prominent with titanium and titanium-zirconium implants compared with zirconium (P < .05). Titanium grade 5 implants with 0.3 and 0.4 mm3 voxels produced the least severe artifacts. MRI images were less affected by artifacts from zirconium implants, whereas CT and CBCT images showed less severe artifacts from titanium and titanium-zirconium alloy implants. CT generated greater artifacts compared with CBCT. Larger CBCT voxel sizes reduced the dose-area product and the severity of artifacts.

A Prospective Case-Control Clinical Study of Titanium-Zirconium Alloy Implants with a Hydrophilic Surface in Patients with Type 2 Diabetes Mellitus.

To evaluate prospectively the behavior of narrow-diameter (3.3-mm) titanium-zirconium alloy implants with a hydrophilic surface (Straumann Roxolid SLActive) in patients with type 2 diabetes mellitus in single-unit restorations, compared with a healthy control group (assessed using the glycosylated hemoglobin HbA1c test). The patients evaluated in this study required single-unit implant treatment; 15 patients had type 2 diabetes mellitus, and 14 patients were healthy (control group [CG]). Marginal bone level (MBL) change around the implants was evaluated using conventional, sequential periapical digital radiographs. Patient HbA1c was assessed in each check-up. Normality test (Kolmogorov-Smirnov), univariate and multivariate logistic regression, analysis of variance (ANOVA), and Mann-Whitney U test were used for statistical analysis. No differences in MBL change and implant survival and success rates were found between the diabetes mellitus group (DMG) versus the control group, either during the initial recording (DMG, 0.99 ± 0.56 vs CG, 0.68 ± 0.54; P > .05) or 6 months after restoration (DMG, 1.28 ± 0.38 vs CG, 1.11 ± 0.59; P > .05). No significant correlation between HbA1c levels and MBL change was detected in these patients (P > .05). Patients with glycemic control exhibit similar outcomes to healthy individuals with regard to the investigated parameters. In light of these findings, the titanium-zirconium alloy small-diameter implants can be used in the anterior region of the mouth in type 2 diabetic patients.

Artefacts in multimodal imaging of titanium, zirconium and binary titanium-zirconium alloy dental implants: an in vitro study.

To analyze and evaluate imaging artefacts induced by zirconium, titanium and titanium-zirconium alloy dental implants. Zirconium, titanium and titanium-zirconium alloy implants were embedded in gelatin and MRI, CT and CBCT were performed. Standard protocols were used for each modality. For MRI, line-distance profiles were plotted to quantify the accuracy of size determination. For CT and CBCT, six shells surrounding the implant were defined every 0.5 cm from the implant surface and histogram parameters were determined for each shell. While titanium and titanium-zirconium alloy induced extensive signal voids in MRI owing to strong susceptibility, zirconium implants were clearly definable with only minor distortion artefacts. For titanium and titanium-zirconium alloy, the MR signal was attenuated up to 14.1 mm from the implant. In CT, titanium and titanium-zirconium alloy resulted in less streak artefacts in comparison with zirconium. In CBCT, titanium-zirconium alloy induced more severe artefacts than zirconium and titanium. MRI allows for an excellent image contrast and limited artefacts in patients with zirconium implants. CT and CBCT examinations are less affected by artefacts from titanium and titanium-zirconium alloy implants compared with MRI. The knowledge about differences of artefacts through different implant materials and image modalities might help support clinical decisions for the choice of implant material or imaging device in the clinical setting.

Numerical assessment of bone remodeling around conventionally and early loaded titanium and titanium–zirconium alloy dental implants

The aim of this study was to investigate conventionally and early loaded titanium and titanium-zirconium alloy implants by three-dimensional finite element stress analysis. Three-dimensional model of a dental implant was created and a thread area was established as a region of interest in trabecular bone to study a localized part of the global model with a refined mesh. The peri-implant tissues around conventionally loaded (model 1) and early loaded (model 2) implants were implemented and were used to explore principal stresses, displacement values, and equivalent strains in the peri-implant region of titanium and titanium-zirconium implants under static load of 300 N with or without 30° inclination applied on top of the abutment surface. Under axial loading, principal stresses in both models were comparable for both implants and models. Under oblique loading, principal stresses around titanium-zirconium implants were slightly higher in both models. Comparable stress magnitudes were observed in both models. The displacement values and equivalent strain amplitudes around both implants and models were similar. Peri-implant bone around titanium and titanium-zirconium implants experiences similar stress magnitudes coupled with intraosseous implant displacement values under conventional loading and early loading simulations. Titanium-zirconium implants have biomechanical outcome comparable to conventional titanium implants under conventional loading and early loading.

Experimental peri‐implant mucositis at different implant surfaces

To histologically and immunologically assess experimental peri-implant mucositis at surface enhanced modified (mod) hydrophilic titanium implants. In a split-mouth design (n=6 foxhounds), four different implants were inserted on each side of the maxilla: three titanium-zirconium alloy implants (TiZr) with either modSLA (sand-blasted, acid etched and chemically mod), modMA (machined, acid etched and chemically mod), or M (machined) surfaces in the transmucosal portion, and one titanium implant with a machined transmucosal portion (TiM). Experimental mucositis was induced at one randomly assigned side (NPC), whereas the contra-lateral maxillary side received mechanical plaque removal three times per week (PC). At 16weeks, tissue biopsies were processed for histological (primary outcome: apical extension of the inflammatory cell infiltrate measured from the mucosal margin - PM-aICT) and immunohistochemical (CD68 antigen reactivity) analyses. Peri-implant sulcus fluid was analysed for interleukin (IL)-1β, IL-8, matrix metalloproteinase (MMP)-8 and myeloperoxidase (MPO). Mean PM-aICT values varied between 1.86 (TiZrmodSLA) and 3.40mm (TiM) in the UPC group, and between 0.88 (TiZrmodSLA) and 2.08mm (TiZrM) in the PC group. Mean CD68, IL-1β, IL-8, MMP-8 and MPO values were equally distributed between mod- and control implants in both NPC and PC groups. The progression of experimental mucositis was comparable at all implant surfaces investigated.