Zr Implants Research Articles

Comparative Clinical Behavior of Zirconia versus Titanium Dental Implants: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Objective: The goal of this systematic review and meta-analysis was to assess whether there were clinically relevant differences in the treatment of edentulous areas comparing zirconia (Zr) and titanium (Ti) dental implants. The null hypothesis is that no differences can be observed in terms of the clinical parameters; the positive hypothesis I is that Zr implants have generally better results compared to Ti implants; and the positive hypothesis II is that Ti implants have a generally superior result than Zr implants. Methods: This review work was registered on the PROSPERO platform, and its development was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. The electronic search process was conducted on three databases (PubMed/Scopus/Web of Science), including randomized controlled trials (RCTs) from the past 10 years (up to April 2024). Identified articles were analyzed and included/excluded based on pre-defined selection and exclusion criteria. The quality assessment and risk of bias were evaluated using a Cochrane risk-of-bias assessment tool specifically designed for randomized trials (RoB2). A meta-analysis was conducted to correlate different treatment options based on the described outcomes; a random-effects model was used in the analysis of the variables. The analysis of heterogeneity was conducted by means of Cochran's Q-test and Higgins' I2 statistic. Results: Six RCTs were enrolled; 152 patients (90 males and 62 females) and 448 implants (267 Zr and 181 Ti) were included. Dental implant placement involved both the maxillary and mandibular arches. The implant sites showed heterogeneity in receiving Zr and Ti dental implants; in particular, 22 dental implants were placed in the mid-palatal region and 426 dental implants in the alveolar region (255 were in Zr and 171 in Ti). Regarding the success rate, it was better for Zr but with no statistical difference (p > 0.05); bleeding on probing had slight differences between Ti with 0.34% ± 0.42 and Zr with 0.26% ± 0.36 (p > 0.05); plaque score showed 0.46 ± 0.47 for Ti compared to 0.44 ± 0.49 for Zr (p > 0.05); no statistically significant difference was observed for pink esthetic score (PES). Statistically significant results were found for survival rate, which favored Ti implants (77.6%) compared to Zr (70.3%) (p < 0.05), and for marginal bone loss, which showed less loss in Ti implants (0.18 mm ± 0.47) compared to 0.42 mm ± 0.40 in Zr at 12 months (p < 0.001). Conclusions: The present systematic review and meta-analysis identified the positive hypothesis I and rejected the null and positive hypothesis II; it was possible to conclude that Ti dental implants have a better survival rate and less marginal bone loss than Zr dental implants after 1-year follow-up.

Clinical, radiographic and patient-reported outcomes of zirconia and titanium implants in the posterior zone after 1 year of loading-A randomized controlled trial.

To assess the clinical, radiographic and patient-reported outcomes (PROMs) of posterior zirconia and titanium implants at 1 year of implant loading. Forty-two patients with two adjacent missing teeth were enrolled in a randomized controlled trial with a within-subject controlled design. Each patient received one zirconia (Zr) and one titanium (Ti) implant, with the mesial and distal positions randomized. The implant restoration consisted of multiple layered zirconia, with the buccal aspect veneered. In group Zr, the restoration was intraorally cemented onto the one-piece Zr implant, whereas in group Ti, the restoration was extraorally cemented onto the titanium base abutment and intraorally screw-retained onto the Ti implant. Examinations were performed following restoration delivery at baseline (BL) and at 1 year. Measurements included clinical parameters, radiographic outcomes (MBL) and PROMs. Bleeding on probing showed an increase from BL to 1 year (34 ± 30% for Zr; 25 ± 21% for Ti). MBL remained stable with minimal changes from BL to 1 year, measuring 0.1 ± 0.4 mm (mean ± SD) for Zr and -0.1 ± 0.7 mm for Ti. Veneering fractures were the most frequent technical complication and amounted to 17.5% in group Zr and 5% in group Ti (p = .100). Patients preferred Zr implants for their soft tissue color, with a significant difference in perception between patients and clinicians (p < .017). The study showed that both Zr and Ti implants had similar clinical outcomes, despite a high prevalence of mucositis and a few technical complications. Both implant types demonstrated stable marginal bone levels and similar patient-reported outcome measures.

Effect of hydroxyapatite coating thickness on inflammation and osseointegration of Ti–29Nb–13Ta-4.6Zr (TNTZ) implants

The study investigates the effect of Hydroxyapatite (HA) coating thickness on the inflammation and osseointegration properties of Ti–29Nb–13Ta-4.6Zr (TNTZ) implants for orthopedic implant applications. TNTZ screws were used as based samples, and the HA coating was deposited using an Electrophoretic Deposition (EPD) method to achieve various coating thickness. The thin (50–70 μm), medium (70–90 μm), and thick (90–110 μm) coating thicknesses were obtained by applying different voltage and time exposure during the EPD process, while the uncoated screw was used as the control sample. The screws were implanted into the right tibia of male Rattus norvegicus Wistar rats, and the animals were kept in cages and provide with ad libitum food for two weeks. After termination of the test animals, blood samples were collected to measure levels of Tumor Necrosis Factor-α (TNF-α) using an ELISA method, and a removal torque test was performed on the implanted screws. Additionally, tibial bone tissue around the implant area was collected for histopathology analysis. The result of the study indicate that HA coating thickness has an effect on TNF-α concentration, removal torque value, and new bone growth. The optimal thickness of the HA layer was found to be in the medium range (70–90 μm), resulting in low inflammation levels, relatively high osseointegration rates, and optimal new bone tissue growth. These finding are expected to be applicable in future orthopedic implant applications.

Differences in Titanium, Titanium-Zirconium, Zirconia Implants Treatment Outcomes: a Systematic Literature Review and Meta-Analysis.

The objective of this systematic review is to test the hypothesis that treatment with titanium, titanium-zirconium and zirconia dental implants has different clinical outcomes in survival rate, marginal bone loss, bleeding on probing, plaque control record, and probing depth. A systematic electronic search through the PubMed (MEDLINE) and Cochrane Library databases was performed to identify studies published between January 1, 2013 and January 1, 2023 containing a minimum of 10 patients per study comparing titanium (Ti), titanium-zirconium (Ti-Zr), and zirconia (Zr) dental implants. Ti, Ti-Zr, and Zr dental implant clinical outcomes were determined by evaluating survival rate, marginal bone level, bleeding on probing, probing depth, plaque control record. Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool. A total of 1361 articles were screened, with 10 meeting the inclusion criteria and being utilized for this systematic review and meta-analysis. A total of 301 patients with 637 implants (304 Ti, 134 Ti-Zr, and 199 Zr) were evaluated, showing a survival rate of 97.7% for Ti, 98.6% for Ti-Zr, and 93.8% for Zr implants respectively. In a meta-analysis, no difference in marginal bone level was found between Ti, Ti-Zr, and Zr implants (P = 0.84). Dental implant survival rate was lower in zirconia group. Assessment of marginal bone loss and bleeding on probing showed better results with titanium-zirconium dental implants. Plaque control result was similar in all groups. Due to limited sample size assessed it was not possible to obtain conclusion on probing depth parameter.

Thermal Effects of 445nm Diode Laser-Irradiation on Titanium and Ceramic Implants.

Purpose This study aimed to evaluate temperature changes in titanium and ceramic implants after using a 445nm-diode laser under different in-vitro conditions. Methods A titanium (Ti) and ceramic (Zr) dental implant were placed into a bone analog, and an intra-bony defect was created at each implant. A 445nm-diode laser was used to irradiate the defects for 30 seconds, non-contact, at 2W in continuous wave (c.w.) and pulsed mode. The experiment was done at room temperature (21.0°C±1) and in a water bath (37.0°C±1). Two thermocouple probes were used to record real-time temperature changes (°C) at the coronal part of the implant (Tc) and the apex (Ta). The temperature was recorded at time 0s (To) and after 30s of irradiation (Tf). The average temperature change was calculated, and a descriptive analysis was conducted (p<0.05). Results The Ti implant resulted in the highest ∆T values coronally (29.6°C) and apically (6.7°C) using continuous wave at 21°C. The Zr implant increased to 26.4°C coronally and 5.2°C apically. In the water bath, the coronal portion of the Ti and Zr implants rose to 14.2°C and 14.01°C, respectively, using continuous waves. The ∆T values for Ti were 11.9°C coronally and 1.7°C apically when placed in a water bath using pulsed mode. The lowest ∆T occurred on the Zr implant with ∆Tc and ∆Ta, 4.8°C and 0.78°C, respectively. Conclusion Under in-vitro conditions, the 445nm-diode laser in pulsed mode seems to be safe for use on ceramic implants and should be used with caution on titanium implants.

Histologic Osseointegration Level Comparing Titanium and Zirconia Dental Implants: Meta-analysis of Preclinical Studies.

Purpose: To assess the literature comparing histologic levels of osseointegration for titanium vs zirconia dental implants. Materials and Methods: This systematic review was conducted following the PRISMA guidelines and was registered in PROSPERO (CRD42021236781). Electronic and manual searches were carried out through the PubMed/MEDLINE, PubMed Central, and Embase databases with a platform-specific search strategy combining controlled terms (MeSH and Emtree) and text words. The articles were selected by two independent investigators who evaluated the articles based on the criteria for eligibility. Results: A total of 17 articles were included. All were preclinical studies. The populations included dogs (27.55%), minipigs (14.28%), rats (14.28%), and rabbits (43.89%); and the implantation site varied among the mandible (36.82%), maxilla (9.04%), tibia (17.64%), skull (10.70%), and femur (25.80%). A total of 370 titanium (Ti) implants and 537 zirconia (Zr) implants were evaluated. The average osseointegration (% bone-to-implant contact) for Zr was 55.51% (17.6% to 89.09%), and for Ti was 58.50% (23.2% to 87.85%). There was no statistical difference between studies at the 2-month follow-up (P = .672), but this difference was significant at 1 and 3 months (P < .001). Conclusions: Within the limitations of this review, Zr implants had a similar level of osseointegration compared to Ti implants. Nonetheless, because these findings are based on preclinical research, all data must be carefully examined.

Fracture strength of screw-retained zirconia crowns assembled on zirconia and titanium implants.

This in vitro study evaluated the fracture strength of screw-retained zirconia crowns connected to zirconia (Zr) and titanium (Ti) implants after undergoing a simulation of 5 years of clinical use. Forty-eight screw-retained zirconia crowns were fabricated and assembled on four implant systems, with 12 in each group: (1) Zr implant (pure ceramic; Straumann AG) (PZr); (2) Zr implant (NobelPearl; Nobel Biocare) (NPZr); (3) Ti-Zr implant (Bone Level Roxolid; Straumann AG) (RSTiZr); (4) Ti implant (Conical Connection PMC; Nobel Biocare) (NRTi). Crowns were luted to their associated abutments using resin cement and then torqued to their assigned implants at the recommended torque value. Specimens were subjected to dynamic loading for 1,200,000 loading cycles. Fracture strength, measured in Newtons (N), was tested under static compression load using a universal testing machine at an angle of 30°. One-way ANOVA and Tukey's multiple comparisons post hoc test were used to compare the mean fracture values between the groups at a significance level of 0.05. The average fracture strengths for the RSTiZr and NRTi groups were 1207±202 and 1073±217N, respectively, which was significantly (p<0.0001) higher than the PZr and NPZr groups (712±76 and 571.6±167N, respectively). However, no significant difference was found between the fracture strength value of RSTiZr and NRTi (p=0.260) or PZr and NPZr (p=0.256) groups. Zirconia crowns connected to Zr implants have the potential to withstand the average physiological occlusal forces which occur in the anterior and premolar regions.

Random, aligned and grassy: Bioactivity and biofilm analysis of Zirconia nanostructures as dental implant modification

Zirconium (Zr)-based implants are rapidly gaining popularity due to their excellent physical, mechanical and biological properties. While Zr-based dental implants have shown promising outcomes, their performance may be suboptimal, especially in compromised conditions. To address this, conventional Zr implants have been modified via physical, chemical and biological means to augment cellular functions to achieve enhanced osseointegration, soft-tissue integration and local therapy. In this study, we fabricated controlled ZrO2 nanostructures (ZONs), including aligned nanopores, random nanopores and nanograss, on clinically relevant micro-machined and rough Zr surfaces via optimized electrochemical anodization. In-depth surface topographical and chemical characterization was performed to confirm the formation of ZONs. Further, the bioactivity performance of ZONs was investigated in vitro using primary human osteoblasts, and the effect on salivary polymicrobial biofilms was explored. The findings revealed that nano-engineered Zirconia augments the activity of osteoblasts without increasing biofilm formation. Anodized nano-engineered Zirconia implants are proposed as potential next-generation dental implants, featuring enhanced healing properties without promoting biofilm formation.

Optimizing the Surface Properties of Zirconium Implants with Germanium Coating

Background: zirconium (Zr) implants are known for having an aesthetically pleasing tooth-like colour Unlike the grey cervical collar that develops over time when titanium (Ti) implants are used in thin gingival biotypes. However, the surface qualities of Zr implants can be further improved. This present study examined using thermal vapour deposition (TVD) to coat Zr implants with germanium (Ge) to improve its physical and chemical characteristics and enhance soft and hard tissue responses. Materials and methods: Zr discs were divided into two groups; the uncoated (control) group was only grit-blasted with alumina particles while the coated (experimental) group was grit-blasted then coated with Ge via TVD. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), water contact angle test, and cross-hatch adhesion tests were then used for surface characterization Results: An XRD analysis of the Ge-coated Zr samples revealed the substrate while the FESEM results revealed a continuous coating with no cracks. The mean surface roughness and hydrophilicity of the Ge-coated Zr substrate was significantly higher than that of the uncoated Zr substrate (P≤0.01). The cross-hatch adhesion of all the samples was 0%, thereby indicating good coating adhesion. Conclusion: Therefore Coating Zr implants with Ge via TVD enhances its physical and chemical properties.

Comparison of In Vitro Biofilm Formation on Titanium and Zirconia Implants.

Peri-implant diseases are emerging issues in contemporary implant dentistry. As biofilms play a critical role in peri-implant diseases, the characteristic of resisting bacterial adhesion would be ideal for dental implants. The aims of the study were to compare titanium (Ti) and zirconia (Zr) implants regarding the amount of biofilm formation at different time frames and assess the distribution of biofilm on different aspects of dental implants. Biofilm was developed on Ti and Zr dental implants with a peri-implant-related multispecies model with Streptococcus oralis, Actinomyces naeslundii, Veillonella dispar, and Porphyromonas gingivalis, for 3 and 14 days. Quantitative assessment was performed with the measurement of total bacterial viability (colony forming units, CFU/mg). Scanning electron microscopy (SEM) was used to evaluate biofilm formation on different aspects of the implants. Three-day-old biofilm on Ti implants was significantly higher than that on Zr implants (p < 0.001). The Ti and Zr groups were not significantly different for 14-day-old biofilm. SEM images demonstrated that 3-day-old biofilm on Zr implants was sparse while biofilm growth was more pronounced for 3-day-old biofilm on Ti implants and 14-day-old biofilm groups. It appeared that less biofilm formed on the valley compared to the thread top for 3-day-old biofilm on Zr implants. Differences between the valley and the thread top became indistinguishable with the development of mature biofilm. While early formed biofilms show greater accumulation on Ti implants compared to Zr implants, older biofilms between the two groups are comparable. The distribution of biofilms was not uniform on different areas of implant threads during early biofilm development.

Influence of the Milliamperage and Artifact Reduction Tool on the CBCT-Based Diagnosis of Buccal and Lingual Peri-implant Dehiscences: Comparison Between Two Types of Implants.

To evaluate the influence of the milliamperage and artifact reduction (AR) tool on the diagnosis of buccal and lingual peri-implant dehiscences related to titanium-zirconia (Ti-Zr) and zirconia (Zr) implants using CBCT images. Ti-Zr and Zr implants were alternately inserted in 20 sites in the posterior region of three human mandibles that presented intact cortical (control) bones or simulated buccal and/or lingual peri-implant dehiscences. CBCT images were acquired with an OP300 Maxio unit, varied milliamperage (5 and 8 mA), and the use of AR tool. Three oral radiologists assessed the presence of dehiscences using a 5-point scale. The area under the receiver operator characteristic curve (Az), sensitivity, and specificity of each group (control and dehiscence) were obtained and compared using multiway ANOVA (α = .05). The milliamperage and the AR tool did not influence the diagnosis of dehiscences, and there were no differences between the buccal and lingual cortices (P > .05). However, Zr implants showed a higher sensitivity (0.67 to 0.89) and lower specificity (0.26 to 0.44) than Ti-Zr implants (0.19 to 0.44 and 0.93 to 1.00, respectively; P < .05). Az values did not differ between the implant types (P > .05). Dehiscences were more detectable when related to Zr implants, while the absence of dehiscences was more correctly visualized adjacent to Ti-Zr implants. The use of varied milliamperages and the AR tool did not affect the diagnosis of peri-implant dehiscences, regardless of the involved cortical (buccal or lingual) bones.

Clinical Performance Comparing Titanium and Titanium-Zirconium or Zirconia Dental Implants: A Systematic Review of Randomized Controlled Trials.

Objectives: This study aimed to compare clinical results between titanium (Ti), zirconia (Zr), or titanium–zirconium (TZ) dental implants and to analyze survival rate (SR), bleeding on probing (BoP), marginal bone loss (MBL), and/or probing depth (PD). Data source: Manual and electronic searches were conducted (PubMed and Web of Science) to identify randomized controlled trials that compared the outcomes of at least two implant types (control and test group) within the same study. The focused question was determined according to the PICOT strategy. Seven studies were included out of 202 research studies initially found. The follow-up periods ranged from 12 to 80 months, and the mean age was from 43.3 to 65.8 years old. The SR for Ti, TZ, and Zr implants ranged from 92.6% to 100%, 95.8% to 100%, and 87.5% to 91.25%, respectively; MBL for Ti, TZ, and Zr implants varied from −1.17 mm to −0.125 mm for Ti, −0.6 mm to −0.32 mm for TZ, and −0.25 mm to −1.38 mm for Zr. Studies showed a low incidence of mucositis and peri-implantitis; however, BoP for Zr was 16.43%, Ti ranged between 10% and 20%, and TZ from 10% to 13.8%. PD for Ti ranged from 1.6 mm to 3.05 mm, TZ was 3.12 mm (only one study), and Zr ranged from 2.21 mm to 2.6 mm. Conclusion: All three types of implants showed similar tissue behavior. However, the TZ group had better results when compared with Ti and Zr for SR, MBL, and BoP, except for PD. Furthermore, the worst SR was found in the Zr implants group.

Influence of kilovoltage-peak and the metal artifact reduction tool in cone-beam computed tomography on the detection of bone defects around titanium-zirconia and zirconia implants.

PurposeThe aim of this study was to assess the influence of kilovoltage-peak (kVp) and the metal artifact reduction (MAR) tool on the detection of buccal and lingual peri-implant dehiscence in the presence of titanium-zirconia (Ti-Zr) and zirconia (Zr) implants in cone-beam computed tomography (CBCT) images.Materials and MethodsTwenty implant sites were created in the posterior region of human mandibles, including control sites (without dehiscence) and experimental sites (with dehiscence). Individually, a Ti-Zr or Zr implant was placed in each implant site. CBCT scans were performed using a Picasso Trio device, with variation in the kVp setting (70 or 90 kVp) and whether the MAR tool was used. Three oral radiologists scored the detection of dehiscence using a 5-point scale. The area under the receiver operating characteristic (ROC) curve, sensitivity, and specificity were calculated and compared by multi-way analysis of variance (α=0.05).ResultsThe kVp, cortical plate involved (buccal or lingual cortices), and MAR did not influence any diagnostic values (P>0.05). The material of the implant did not influence the ROC curve values (P>0.05). In contrast, the sensitivity and specificity were statistically significantly influenced by the implant material (P<0.05) with Zr implants showing higher sensitivity values and lower specificity values than Ti-Zr implants.ConclusionThe detection of peri-implant dehiscence was not influenced by kVp, use of the MAR tool, or the cortical plate. Greater sensitivity and lower specificity were shown for the detection of peri-implant dehiscence in the presence of a Zr implant.

Enhanced bioactivity and antibacterial properties of anodized ZrO2 implant coatings via optimized nanoscale morphology and timed antibiotic release through PLGA overcoat

Surface modification of Zirconium (Zr) with Zirconia (ZrO2) nanotubes (NTs) was performed using a two-step electrochemical anodization to investigate the role of such a modified surface in apatite formation and the inhibition of bacterial growth on Zr implants. Pore size at the surface of the NT arrays was controlled, along with the NT length, by varying the 2nd-step anodizing time duration. Nearly four-fold changes in the pore size were achieved by varying the anodization at the second anodizing step. The apatite formation on the implant surfaces plays an important role in the osteointegration process, which can be greatly influenced by the morphology and crystalline structure of the surface. XRD analysis of the anodized surfaces identified a mixed phase of monoclinic and tetragonal ZrO2 NTs with the crystallite size decreasing with increased 2nd anodizing time duration. Surface roughness of the ZrO2 NTs decreased with an increase in anodizing time duration. The ZrO2 NTs with the largest pore sizes, and the smallest crystallite sizes (ZrO2-15 m) favoured the deposition of a Ca-rich compound on their surfaces following 24 days of soaking in SBF, and showed the highest apatite-forming ability among all studied samples. Antibacterial tests showed that the ZrO2-15 m sample exhibited antibacterial properties with 1log10 CFU/mL reduction of S. aureus and E. coli incubated in a buffer solution for 4 h. Loading the NT layer with antibacterial drug led to a complete inhibition of both bacterial species. The rate of drug release was slowed down by dip coating the drug loaded NTs in a PLGA solution. A higher number of dip-coating steps not only slowed down the release of the drug, it also led to a higher suppression of growth in both bacteria. Longer antibiotic exposure and optimized dosage of the drug released from ZrO2 NTs can therefore be managed by modifying the NT morphology and the number of PLGA dip-coating steps.

Towards Clinical Translation: Optimized Fabrication of Controlled Nanostructures on Implant-Relevant Curved Zirconium Surfaces.

Anodization enables fabrication of controlled nanotopographies on Ti implants to offer tailorable bioactivity and local therapy. However, anodization of Zr implants to fabricate ZrO2 nanostructures remains underexplored and are limited to the modification of easy-to-manage flat Zr foils, which do not represent the shape of clinically used implants. In this pioneering study, we report extensive optimization of various nanostructures on implant-relevant micro-rough Zr curved surfaces, bringing this technology closer to clinical translation. Further, we explore the use of sonication to remove the top nanoporous layer to reveal the underlying nanotubes. Nano-engineered Zr surfaces can be applied towards enhancing the bioactivity and therapeutic potential of conventional Zr-based implants.

Effect of anodized zirconium implants on early osseointegration process in adult rats: a histological and histomorphometric study

Since surface plays a key role in bioactivity, the response of the host to the biomaterial will determine the success or failure of the prosthesis. The purpose of this study is to make an exhaustive analysis of the histological and histochemical characteristics of new bone tissue around Zr implants anodized at 60 V (Zr60) supported by histomorphometric methods in a rat model. Fibrous tissue was observed around the control implants (Zr0) and osteoblasts were identified on the trabeculae close to the implantation site that showed typical cytological characteristics of active secretory cells, regardless of the surface condition. The histomorphometrical analysis revealed a significant increase in cancellous bone volume, trabecular thickness and in trabecular number together with a decrease in trabecular separation facing Zr60. TRAP staining showed that there was a relative increase in the number of osteoclasts for Zr60. In addition, a larger number of osteoclast with a greater number of nuclei were detected in the tibiae for Zr60. This research demonstrated that the new bone microarchitecture in contact with Zr60 is able to improve the early stages of the osseointegration process and consequently the primary stability of implants which is a crucial factor to reduce recovery time for patients.

Assessment of magnetic field interactions, radiofrequency, and radiation‐induced heating of Zr implants in 7 T MR scanner

Assessment of magnetic field interactions, radiofrequency, and radiation‐induced heating of Zr implants in 7 T MR scanner

Estimation of contrast-to-noise ratio in CT and CBCT images with varying scan settings in presence of different implant materials.

To assess the contrast-to-noise ratio (CNR) of four different types of dental implant materials in CT and cone beam CT (CBCT) images with varying scan settings. Four different types of implants: zirconium (Zr), titanium (Ti) Grade 4 and 5 and titanium-zirconium (Ti-ZrO2) alloy were placed in a 3% gelatin phantom in a cylindrical plastic container and scanned with two different CT machines (GE Medical systems and Toshiba Medical Systems) and one CBCT machine (I-CAT, Imaging Sciences International) with different voxel sizes of 0.2, 0.25, 0.3 and 0.4 mm. Images were analyzed using ImageJ software with the purpose of estimating the CNR. The CNR obtained from images acquired with CT was lower than the CBCT with all voxel sizes tested. 0.3 and 0.4 mm voxel sizes exhibited the highest CNR (p < 0.05) that gives the best image quality. Among the implant materials tested, titanium Grade 5 has the highest levels of CNR while Zirconium has the lowest (p < 0.05). The optimum protocol for radiographic follow-up in areas near implants on the I-CAT is low-resolution settings (0.3 and 0.4 mm voxel sizes) which gave the highest CNR thus image quality. In presence of Zr implants, an alternative imaging modality (i.e., MRI) may be considered to avoid low-quality images.

Cell and tissue response to nanotextured Ti6Al4V and Zr implants using high-speed femtosecond laser-induced periodic surface structures

In this paper, the effect of femtosecond laser nanotexturing of surfaces of Ti6Al4V and Zr implants on their biological compatibility is presented and discussed. Highly regular and homogeneous nanostructures with sub-micrometer period were imprinted on implant surfaces. Surfaces were morphologically and chemically investigated by SEM and XPS. HDFa cell lines were used for toxicity and cell viability tests, and subcutaneous implantation was applied to characterize tissue response. HDFa proliferation and in vivo experiments evidenced the strong influence of the surface topography compared to the effect of the surface elemental composition (metal or alloy). The effect of protein adsorption from blood plasma on cell proliferation is also discussed.

Epithelial sealing effectiveness against titanium or zirconia implants surface.

The aims of implant treatment now involve not only restoration of mastication function, but also recovery of esthetics. Currently, zirconia is widely used as an esthetic material for implant abutment. Therefore, it is very important to understand the efficacy of zirconia for epithelial sealing as an implant material. We compared the effects of materials on the sealing of the peri-implant epithelium (PIE) to titanium (Ti) or zirconia (Zr) implants, for application to clinical work. Maxillary first molars were extracted from rats and replaced with Ti or Zr implants. The sealing of the PIE to the implants was evaluated with immunohistochemistry observation and HRP analysis. The morphological and functional changes in rat oral epithelial cells (OECs) cultured on Ti or Zr plates were also evaluated. After 4 weeks, the PIE on the Ti and Zr implants showed similar structures. The Zr implants appeared to form a weak epithelial seal at the tissue-implant interface, and exhibited markedly less adhesive structures than the Ti implants under electron microscopic observation. In the in vitro experiments, decreased expression levels of adhesion proteins were observed in OECs cultured on Zr plates compared with those cultured on Ti plates. In addition, the cell adherence on Zr plates was reduced, while the cell migration was low on Ti plates. Zr is a better choice for an esthetic implant material, but needs further improvement for integration with the epithelial wound healing process around a dental implant. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.