Surface Of Dental Implants Research Articles

Mechanical Properties and Corrosion Behavior of Ti6Al4V Particles Obtained by Implantoplasty: An In Vitro Study. Part II.

In the field of implant dentistry there are several mechanisms by which metal particles can be released into the peri-implant tissues, such as implant insertion, corrosion, wear, or surface decontamination techniques. The aim of this study was to evaluate the corrosion behavior of Ti6Al4V particles released during implantoplasty of dental implants treated due to periimplantitis. A standardized protocol was used to obtain metal particles produced during polishing the surface of Ti6Al4V dental implants. Physicochemical and biological characterization of the particles were described in Part I, while the mechanical properties and corrosion behavior have been studied in this study. Mechanical properties were determined by means of nanoindentation and X-ray diffraction. Corrosion resistance was evaluated by electrochemical testing in an artificial saliva medium. Corrosion parameters such as critical current density (icr), corrosion potential (ECORR), and passive current density (iCORR) have been determined. The samples for electrochemical behavior were discs of Ti6Al4V as-received and discs with the same mechanical properties and internal stresses than the particles from implantoplasty. The discs were cold-worked at 12.5% in order to achieve the same properties (hardness, strength, plastic strain, and residual stresses). The implantoplasty particles showed a higher hardness, strength, elastic modulus, and lower strain to fracture and a compressive residual stress. Resistance to corrosion of the implantoplasty particles decreased, and surface pitting was observed. This fact is due to the increase of the residual stress on the surfaces which favor the electrochemical reactions. The values of corrosion potential can be achieved in normal conditions and produce corroded debris which could be cytotoxic and cause tattooing in the soft tissues.

Critical Role of Etching Parameters in the Evolution of Nano Micro SLA Surface on the Ti6Al4V Alloy Dental Implants.

The surface of dental implants plays a vital role in early and more predictable osseointegration. SLA (sandblasted large grit and acid-etched) represents the most widely accepted, long-term clinically proven surface. Primarily, dental implants are manufactured by either commercially pure titanium (CP-Ti) or Ti6Al4V ELI alloy. The acid etch behavior of CP-Ti is well known and its effects on the surface microstructure and physicochemical properties have been studied by various researchers in the past. However, there is a lack of studies showing the effect of acid etching parameters on the Ti6Al4V alloy surface. The requirement of the narrow diameter implants necessitates implant manufacturing from alloys due to their high mechanical properties. Hence, it is necessary to have an insight on the behavior of acid etching of the alloy surface as it might be different due to changed compositions and microstructure, which can further influence the osseointegration process. The present research was carried out to study the effect of acid etching parameters on Ti6Al4V ELI alloy surface properties and the optimization of process parameters to produce micro- and nanotopography on the dental implant surface. This study shows that the Ti6Al4V ELI alloy depicts an entirely different surface topography compared to CP-Ti. Moreover, the surface topography of the Ti6Al4V ELI alloy was also different when etching was done at room temperature compared to high temperature, which in turn affected the behavior of the cell on these surfaces. Both microns and nano-level topography were achieved through the optimized parameters of acid etching on Ti6Al4V ELI alloy dental implant surface along with improved roughness, hydrophilicity, and enhanced cytocompatibility.

Laser textured novel patterns on Ti6Al4V alloy for dental implants surface improvement

Creating laser texture on dental implants is a novel method for accelerating osseointegration and prolongation of lifespan. The purpose of this research was twofold: (1) Creating intersecting lines pattern with different angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°) on the surface of Ti6Al4V, using pulse Nd:YAG laser with a wavelength of 1064 nm and a pulse length of 170 ns and (2) comparing optical and SEM images, EDS analyses, contact angles (CAs), and surface free energies (FEs) for different intersecting lines angles. CA and FE depended on the intersecting lines angle according to Y=Y0+Asin(xB+C), where Y is the CA or FE; x is the intersecting lines angle; and Y0, A, B, and C are constants. Oxygen was present on all samples. The lowest CA and the highest FE occurred at 60° intersecting lines. FE was independent of minor changes in the microgrooves' depth, intersections' number, and the number of texture lines.

Human Periodontal Ligament Stem Cells Response to Titanium Implant Surface: Extracellular Matrix Deposition.

Simple SummaryThe extracellular matrix (ECM) is a fundamental component of tissues and organs, providing the structural and non-structural support that leads to the bone osseointegration. Understanding the mechanisms of ECM components modulation is essential for developing novel strategies for tissue engineering and regenerative medicine and in particular for the dental implant surface design. The release of ECM components by cells is the first step that leads to the early stage of bone formation. The present work is focused on the modulation of ECM components expression by human periodontal ligament stem cells (hPDLSCs) cultured on two different dental implant surfaces, sandblasted (CTRL) and dual acid-etched (TEST). The effects were evaluated by means of the morphological observations and protein and gene expression. The results demonstrated that the rough surface of titanium dental implant can enhance the expression of ECM molecules and osteogenic markers in hPDLSCs. The surface topography is of vital importance as it regulates cell response. It can be considered one of the main factors that influence the success of a dental implant. The influence of surface topography on osseointegration could lead to short healing times and a better quality of oral rehabilitation and patient life.The major challenge for dentistry is to provide the patient an oral rehabilitation to maintain healthy bone conditions in order to reduce the time for loading protocols. Advancement in implant surface design is necessary to favour and promote the osseointegration process. The surface features of titanium dental implant can promote a relevant influence on the morphology and differentiation ability of mesenchymal stem cells, induction of the osteoblastic genes expression and the release of extracellular matrix (ECM) components. The present study aimed at evaluating the in vitro effects of two different dental implants with titanium surfaces, TEST and CTRL, to culture the human periodontal ligament stem cells (hPDLSCs). Expression of ECM components such as Vimentin, Fibronectin, N-cadherin, Laminin, Focal Adhesion Kinase (FAK) and Integrin beta-1 (ITGB1), and the osteogenic related markers, as runt related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP), were investigated. Human PDLSCs cultured on the TEST implant surface demonstrated a better cell adhesion capability as observed by Scanning Electron Microscopy (SEM) and immunofluorescence analysis. Moreover, immunofluorescence and Western blot experiments showed an over expression of Fibronectin, Laminin, N-cadherin and RUNX2 in hPDLSCs seeded on TEST implant surface. The gene expression study by RT-PCR validated the results obtained in protein assays and exhibited the expression of RUNX2, ALP, Vimentin (VIM), Fibronectin (FN1), N-cadherin (CDH2), Laminin (LAMB1), FAK and ITGB1 in hPDLSCs seeded on TEST surface compared to the CTRL dental implant surface. Understanding the mechanisms of ECM components release and its regulation are essential for developing novel strategies in tissue engineering and regenerative medicine. Our results demonstrated that the impact of treated surfaces of titanium dental implants might increase and accelerate the ECM apposition and provide the starting point to initiate the osseointegration process.

Оптимизация подходов к реабилитации пациентов с потерей зубов с применением современных клинико-диагностических методов

After determining the need for complex types of restoration of chewing efficiency, which amounted to 22% of the total number of prosthetics performed in dental clinics in Bishkek, Kyrgyzstan, the optimal modern clinical and diagnostic methods that can be used according to the experience of the Biodent clinic, Bishkek were summarized. Cone-beam computed tomography recognized as the gold standard for radiological examination and modeling of dental implantation. The diagnostic accuracy was 99.2% versus 70.5% with orthopantomography. Treatment of the surface of dental titanium implants with nano-solutions of gold and silver, which have antiseptic and engraftment-improving properties in the clinic, leads to an improvement in the results of engraftment and functioning, confirmed by biochemical studies.

Quality Assessment of Five Randomly Chosen Ceramic Oral Implant Systems: Cleanliness, Surface Topography, and Clinical Documentation.

After some initial setbacks in the 1970s, ceramic implants seem to be a promising alternative to titanium implants. Since the surface of an implant system represents the interface to surrounding biologic structures, the study focuses on cleanliness and surface topography. Clinical documentation of the corresponding systems completes the picture and allows a better evaluation of zirconia implant systems. Five different ceramic implant systems were selected randomly and purchased via blind-shopping: Z5s (Z-Systems), ZiBone (COHO), W implant (TAVDental), ceramic. implant (vitaclinical), and BioWin!/Standard Zirkon Implantat (Champions-Implants/ZV3 system). Three samples of each implant system underwent scanning electron microscopy (SEM) imaging and elemental analysis (EDS). Where appropriate, subsequent Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) was performed to identify the chemical nature of impurities. Surface topography was evaluated, and a search for clinical trials in the PubMed database, on the websites and by written request to each dental implant manufacturer, was performed. Surfaces of Champions implants (ZV3) and Z-Systems implants were relatively clean, whereas the other investigated surfaces of vitaclinical, TAV Dental, and ZiBone implants all displayed organic contaminations on their surfaces. Four of the investigated ceramic implants showed a moderately rough implant surface. Only the vitaclinical ceramic.implant had minimal surface roughness. Three ceramic designs-vitaclinical, ZV3, and Z-Systems-had clinical trials documented with up to 3 years of follow-up and results varying between 82.5% and 100% survival. TAV Dental W and ZiBone implant systems lacked properly conducted clinical recording of results. The results of this study showed that it is technically possible to produce zirconia implants that are largely residue-free. On the other hand, the variety of significant residues found in this analysis raises concerns, as contamination may lead to undesirable biologic effects. The lack of clinical studies in peer-reviewed journals does not seem to be relevant for the approval of marketing, nor does the lack of surface cleanliness. In the authors' opinion, a critical analysis of these aspects should be included in a more stringent future analysis prior to the marketing of oral implant systems.

The Effect of Different Dental Implant Surface Characteristics on Bone Immunologic Biomarkers and Microbiologic Parameters: A Randomized Clinical Study.

This study assessed the levels of tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), receptor activator of nuclear factor kappa B (RANK), RANK ligand (RANKL), osteoprotegerin (OPG), and levels of Fusobacterium nucleatum, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Prevotella intermedia, and Streptococcus oralis in areas where airborne particle-abraded, large-grit, acid-etched (SLA), fluorine-modified, and anodized implant surfaces are used. A total of 71 implants from 37 patients were assessed, grouped according to the surface characteristics of the implants: SLA surface (Group 1), fluorine-modified surface (Group 2), and anodized surface (Group 3). The following clinical indices were measured: Gingival Index (GI), probing depth (PD), bleeding on probing (BOP), clinical attachment level (CAL), and keratinized tissue width (KTW). Peri-implant sulcus fluid and subgingival plaque samples were also collected. Commercial enzyme-linked immunosorbent assay (ELISA) kits were purchased for measuring TNF-α, PGE2, RANKL, RANK, and OPG. Real-time quantitative polymerase chain reaction (PCR) was used to detect P intermedia, T forsythia, T denticola, F nucleatum, P gingivalis, and S oralis levels in the subgingival biofilms. The groups showed no statistically significant differences in GI, PD, BOP, CAL, KTW, or peri-implant status. The total amounts of PGE2, TNF-α, RANKL, RANK, and OPG and the RANKL/OPG ratio were not significantly different between groups. F nucleatum, T forsythia, P intermedia, P gingivalis, and T denticola were significantly higher in Group 3 implants. DNA concentrations of S oralis were higher in Group 2. Within the limitations of this study, SLA and fluorine-modified implant surfaces may be more clinically successful than anodized-surface implants.

Reactivity of Titanium Dental Implant Surfaces in Simulated Body Fluid.

Osseointegration of titanium (Ti) implants in bone is crucial for dental implant treatment. Bacterial challenge possibly leading to peri-implantitis threatens long-term success. For the improvement of osseointegration, an understanding of materials and tissue intervention is needed. This in vitro study analyzed changes of different implant surfaces exposed to simulated body fluid (SBF). Implants were analyzed by scanning electron microscopy/X-ray photoelectron spectroscopy. Supernatants (SNs) were assessed using inductively coupled plasma-mass spectrometry (ICP-MS). Additional calcium (Ca) and phosphate (P) crystals developed (Hank's buffered salt solution (HBSS)) on implants with layered surfaces. ICP of SN demonstrated a decreased Ca/P ratio. After incubation with human serum (HS), layers appeared flattened containing <1% Ca/P. The etched/machined implants showed the formation of a surface transformation layer or coating consisting of crystalline Ca/P precipitations and a decrease in the Ca/P ratio in the supernatant. Incubation in HS induced noncrystalline coverage, and increased Ti/Ca/P was detected in supernatants. HBSS induced crystals on surfaces of modified implants and crystalline covers on nonmodified implants containing Ca/P. The serum did not show the development of HA-like structures but showed dissolving effects. Titanium surfaces show completely altered behavior when incubated in serum-containing SBF.

Mineralization of Titanium Surfaces: Biomimetic Implants

The surface modification by the formation of apatitic compounds, such as hydroxyapatite, improves biological fixation implants at an early stage after implantation. The structure, which is identical to mineral content of human bone, has the potential to be osteoinductive and/or osteoconductive materials. These calcium phosphates provoke the action of the cell signals that interact with the surface after implantation in order to quickly regenerate bone in contact with dental implants with mineral coating. A new generation of calcium phosphate coatings applied on the titanium surfaces of dental implants using laser, plasma-sprayed, laser-ablation, or electrochemical deposition processes produces that response. However, these modifications produce failures and bad responses in long-term behavior. Calcium phosphates films result in heterogeneous degradation due to the lack of crystallinity of the phosphates with a fast dissolution; conversely, the film presents cracks, which produce fractures in the coating. New thermochemical treatments have been developed to obtain biomimetic surfaces with calcium phosphate compounds that overcome the aforementioned problems. Among them, the chemical modification using biomineralization treatments has been extended to other materials, including composites, bioceramics, biopolymers, peptides, organic molecules, and other metallic materials, showing the potential for growing a calcium phosphate layer under biomimetic conditions.

Assessment of the Tissue Response to Modification of the Surface of Dental Implants with Carboxyethylphosphonic Acid and Basic Fibroblastic Growth Factor Immobilization (Fgf-2): An Experimental Study on Minipigs.

Simple SummaryThis study aimed to evaluate the efficacy of treating the surface of dental implants with carboxyethylphosphonic acid for the immobilization of FGF-2, the influence of FGF-2 on cortical bone in close contact with dental implants, new bone formation around dental implants in the presence of FGF-2 and the influence of FGF-2 on the interthread bone area of dental implants during the healing period after insertion.The aim of this study was to evaluate the effect of implant surface treatment with carboxyethylphosphonic acid and fibroblast growth factor 2 on the bone–implant interface during the osseointegration period in vivo using an animal model. The present research was carried out in six minipigs, in whose left tibia implants were inserted as follows: eight implants with a standard surface treatment, for the control group, and eight implants with a surface treatment of carboxyethylphosphonic acid and immobilization of FGF-2, for the test group. At 4 weeks after the insertion of the implants, the animals were sacrificed for the histomorphometric analysis of the samples. The means of the results for the implant–bone contact variable (BIC) were 46.39 ± 17.49% for the test group and 34.00 ± 9.92% for the control group; the difference was not statistically significant. For the corrected implant–bone contact variable (BICc), the mean value of the test group was 60.48 ± 18.11%, and that for the control group, 43.08 ± 10.77%; the difference was statistically significant (p-value = 0.035). The new bone formation (BV/TV) showed average results of 27.28 ± 3.88% for the test group and 26.63 ± 7.90% for the control group, meaning that the differences were not statistically significant (p-value = 0.839). Regarding the bone density at the interthread level (BAI/TA), the mean value of the test group was 32.27 ± 6.70%, and that of the control group was 32.91 ± 7.76%, with a p-value of 0.863, while for the peri-implant density (BAP/TA), the mean value of the test group was 44.96 ± 7.55%, and that for the control group was 44.80 ± 8.68%, without a significant difference between the groups. The current research only found a significant difference for the bone–implant contact at the cortical level; therefore, it could be considered that FGF-2 acts on the mineralization of bone tissue. The application of carboxyethylphosphonic acid on the surface of implants can be considered a promising alternative as a biomimetic coating for the immobilization of FGF-2. Despite no differences in the new bone formation around the implants or in the interthread or peri-implant bone density being detected, the biofunctionalization of the implant surface with FGF-2 accelerates the mineralization of the bone–implant interface at the cortical level, thereby reducing the osseointegration period.

Plant-Derived Nanobiomaterials as a Potential Next Generation Dental Implant Surface Modifier

Dental implants resemble synthetic materials, mainly designed as teeth-mimics to replace the damaged or irregular teeth. Specifically, they are demarcated as a surgical fixture of artificial implant materials, which are placed into the jawbone, and are allowed to be fused with the bone, similar to natural teeth. Dental implants may be categorized into endosteal, subperiosteal, and zygomatic classes, based on the placement of the implant “in the bone” or on top of the jawbone, under the gum tissue. In general, titanium and its alloys have found everyday applications as common, successful dental implant materials. However, these materials may also undergo corrosion and wear, which can lead to degradation into their ionic states, deposition in the surrounding tissues, as well as inflammation. Consequently, nanomaterials are recently introduced as a potential alternative to replace the conventional titanium-based dental implants. However, nanomaterials synthesized via physical and chemical approaches are either costly, non/less biocompatible, or toxic to the bone cells. Hence, biosynthesized nanomaterials, or bionanomaterials, are proposed in recent studies as potential non-toxic dental implant candidates. Further, nanobiomaterials with plant origins, such as nanocelluloses, nanometals, nanopolymers, and nanocarbon materials, are identified to possess enhanced biocompatibility, bioavailability and no/less cytotoxicity with antimicrobial efficacy at low costs and ease of fabrication. In this minireview, we present an outline of recent nanobiomaterials that are extensively investigated for dental implant applications. Additionally, we discuss their action mechanisms, applicability, and significance as dental implants, shortcomings, and future perspectives.

Past, Present and Future of the Dental Implant Topography

Osseointegration means the interlocking of bone and implant surface. The surface of dental implants played a key role for osseointegration. Commercially pure titanium implants (CPTi) grade 4 implant shows high corrosion resistance and fatigue strength. Most commercial implants use this Titanium and modify the surface with moderate roughness (1~100μm). Moderately roughness offers most effective bone to implant contact and high-est removal torque based on the biological stability. As in the surface roughness, biofilm can be formed easily, peri-implantitis is a next challenge of the implant surface modification. It has been expected to overcome the biological complication of dental implants with the nano technology. However, nano technology has been studied limitedly in the laboratory. The implant surface will be developed with the aim of having fast osseointegration, long-term BIC interlock-ing, and high bacterial resistance.

Chemical Evaluation of Energy Dispersive X-ray Spectroscopy Analysis of Different Failing Dental Implant Surfaces: A Comparative Clinical Trial.

The aim of the present study is to compare two different implant surface chemistries of failing dental implants. Sixteen patients (mean age: 52 ± 8.27 with eight females and eight males) and 34 implants were included in the study. Group-I implants consisted of a blasted/etched surface with a final process surface, while Group-II implants consisted of the sandblasted acid etching (SLA) method. The chemical surface analysis was performed by the energy dispersive X-ray spectroscopy (EDX) method from coronal, middle, and apical parts of each implant. Titanium (Ti) element values were found to be 20.22 ± 15.7 at.% in Group I and 33.96 ± 13.62 at.% in Group-II in the middle of the dental implants. Aluminum (Al) element values were found to be 0.01 ± 0.002 in Group-I and 0.17 ± 0.28 at.% in Group II in the middle of the dental implants, and statistically significant differences were found between the groups for the Al and Ti elements in the middle of the dental implants (p < 0.05). There was a statistically significant difference for the Ti, Al, O, Ca, Fe, P, and Mg elements in the coronal, middle, and apical parts of the implants in the intragroup evaluation (p < 0.05). It is reported that different parts of the implants affected by peri-implant inflammation show different surface chemistries, from coronal to apical, but there is no difference in the implants with different surfaces.

Citric Acid Passivation of Titanium Dental Implants for Minimizing Bacterial Colonization Impact

Surface topography and physical-chemical properties usually play a key-role in both osseointegration improvement and bacterial colonization reduction over the surface of dental implants. The aim of this study is to compare the chemical and bacteriological behavior of two different acid passivation surface treatments on titanium c.p. grade 3 used for dental implant manufacturing. Surface roughness was evaluated using White Light Interferometry (WLI) in order to determine different roughness parameters such as average roughness (Sa), the spacing parameter (Sm) and the hybrid parameter of surface index area (SIA). Contact angle (CA) and surface free energy (SFE) were evaluated in order to establish the surface wettability of the different groups of samples. Titanium ion-release from the different samples was also been analyzed in Hank’s solution medium at 37 °C by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) at different immersion times. Bacterial viability adhesion assays were done using S. sanguinis (CECT 480, Spain) as a bacterial strain model of primary colonizer in oral biofilm formation. The bacteria attachment and morphology on Ti surfaces were determined using a live/dead staining method after 4 h of incubation and further analyzed by scanning electron microscope (SEM). Acid passivation surface treatments produced a statistically-significant (p &lt; 0.05) roughness increase in all the evaluated parameters (Sa, Sm, SAI). The treatment with citric acid decreased the static contact angle (CA) and caused an increase in surface free energy (SFE) with a high polarization and oxidizing character. These physical-chemical surface characteristics obtained by means of citric acid passivation caused the bactericidal behavior as it has been proved in bacterial studies.

Blood Wettability of Different Dental Implant Surfaces after Different Pre-Treatments: Ultrasonic Instrumentation, Platelet-Rich Fibrin Coating, and Acid Etching. An In Vitro Study

Background: The blood wettability of titanium implant surfaces favors primary osseointegration and tissue healing in peri-implantitis. The current study aims to evaluate this property on the main different kinds of surfaces, brand new and after treatments. Methods: grade IV titanium disks were used, five machined, five laser-treated, five sandblasted. The experiment was on four steps. Between each step, specimens were sterilized. At the end of each step, a 4 µL blood drop was put on the samples, and contact angles were calculated. The steps consisted of—1: no treatment; 2: surface instrumentation with an ultrasonic titanium tip; 3: platelet-rich fibrin (PRF) coating and drying with sterile gauze; 4: etching with phosphoric acid, rinse and saline solution and air-drying. At the end of each phase, a blood drop was placed on the surfaces. Blood for PRF preparation and for calculation of contact angles was collected from a single source. Results: average wettability decreased after instrumentation, and increased after the PRF application to a superior level both to the first and second steps. The highest wettability was obtained after etching. This trend is statistically significant for machined and sandblasted surfaces. Conclusions: In the clinical environment, PRF and phosphoric acid used for conditioning exposed implant surfaces can be used for the healing of peri-implant tissues.

Acceleration of Bone Formation and Adhesion Ability on Dental Implant Surface via Plasma Electrolytic Oxidation in a Solution Containing Bone Ions

The present study examined the in vitro and in vivo bone formation and adhesion ability on the surface of a titanium dental implant made by plasma electrolytic oxidation (PEO) in electrolytes containing bioactive ions. To achieve this goal, screw-shaped fabricated Ti-6Al-4V alloy implants were processed via PEO using an electrolyte solution containing calcium (Ca), phosphorous (P), magnesium (Mg), zinc (Zn), strontium (Sr), silicon (Si), and manganese (Mn) species. The screw implants doped with bioactive elements via PEO were placed in rabbit tibia, and the results were compared to the sand-blasted Ti-6Al-4V alloy implants. At eight-week post-surgery, there was no significant difference in the values of removal torque between sand-blasted and PEO-treated implants. However, it was observed that the PEO treatment of dental implants led to the formation of more periphery bone as compared to the case of sand-blasted implants. Accordingly, the PEO-treated implants have the potential to be used as promising materials for dental applications.

Optimization of the surface of titanium dental implants of grade 5 alloy by barrier glass ceramic coating

Optimization of the surface of titanium dental implants of grade 5 alloy by barrier glass ceramic coating

Dental Implants Surface in vitro Decontamination Protocols.

Objective The number of patients rehabilitated with dental implants has contributed to increased incidence of peri-implant diseases. Due to complex and difficult treatment, peri-implantitis is a challenge and an efficient clinical protocol is not yet established. Aim of this study was to evaluate the efficacy of two protocols for in vitro decontamination of dental implants surface. Materials and Methods Twenty titanium implants (BioHE-Bioconect) were used. Implants were divided into five groups ( n = 4). NC group (negative control): sterile implants; PC group (positive control): biofilm contaminated implants; S group: biofilm contaminated implants, brushed with sterile saline; SB group: biofilm contaminated implants, brushed with sterile saline and treated with air-powder abrasive system with sodium bicarbonate (1 minute); and antimicrobial photodynamic therapy (aPDT) group: biofilm contaminated implants, brushed with sterile saline and treated with antimicrobial photodynamic therapy (red laser + toluidine blue O). The implants were contaminated in vitro with subgingival biofilm and distributed in groups PC, S, SB, and aPDT. Each group received the respective decontamination treatment, except groups NC and PC. Then, all implants were placed in tubes containing culture medium for later sowing and counting of colony-forming units (CFUs). Statistical Analysis One-way analysis of variance and Tukey tests were performed, at 5% significance level. Results Significantly fewer CFUs were observed in the aPDT group (19.38 × 10 5 ) when compared with groups SB (26.88 × 10 5 ), S (47.75 × 10 5 ), and PC (59.88 × 10 5 ) ( p < 0.01). Both the aPDT and SB groups were statistically different from the NC group ( p < 0.01). Conclusion Proposed protocols, using air-powder abrasive system with sodium bicarbonate and aPDT, showed to be efficacious in the decontamination of dental implants surface in vitro .

Quantitative ultrasound assessment of the influence of roughness and healing time on osseointegration phenomena

The evolution of bone tissue quantity and quality in contact with the surface of orthopedic and dental implants is a strong determinant of the surgical outcome but remains difficult to be assessed quantitatively. The aim of this study was to investigate the performance of a quantitative ultrasound (QUS) method to measure bone-implant interface (BII) properties. A dedicated animal model considering coin-shaped titanium implants with two levels of surface roughness (smooth, Sa = 0.49 µm and rough, Sa = 3.5 µm) allowed to work with a reproducible geometry and a planar interface. The implants were inserted in rabbit femurs and tibiae for 7 or 13 weeks. The ultrasonic response of the BII was measured ex vivo, leading to the determination of the 2-D spatial variations of bone in contact with the implant surface. Histological analysis was carried out to determine the bone-implant contact (BIC) ratio. The amplitude of the echo was significantly higher after 7 weeks of healing time compared to 13 weeks, for both smooth (p < 0.01) and rough (p < 0.05) implants. A negative correlation (R = − 0.63) was obtained between the ultrasonic response and the BIC. This QUS technique is more sensitive to changes of BII morphology compared to histological analyses.

Bioinspired antibacterial surface for orthopedic and dental implants.

Bacterial infections still present a significant concern in orthopedic and dental implant failure. Previous investigations have focused on modifying the surface texture, roughness, or coating implants with antibiotics to provide enhanced anti-bacterial properties. However, they have demonstrated limited success. In this study, we attempted to engineer the titanium (Ti) alloy surface biomimetically at the nano level using alkaline hydrothermal treatment (AHT) inspired by cicada's wing structure. Two modified surfaces of Ti plates were developed using 4 and 8-hr AHT at 230°C. We found that the control plates showed a relatively smooth surface, with little artifacts on the surface. In contrast, 4-hr AHT and 8-hr AHT plates showed nano-spikes of heights around 250-350 and 100-1,250 nm, respectively, that were distributed randomly all over the surface. We found a statistically significant (p < 0.05) number of non-viable cells for both S. aureus and P. aeruginosa bacterial strains when incubated for 1hr in a dynamic environment when compared with the control group. The 8-hr AHT groups killed 38.97% more S. aureus in static culture and 11.27% in a dynamic environment than the 4-hr AHT. Overall, the findings indicate that the nanostructures generated on titanium by the AHT showed significant bactericidal properties. We, therefore, recommend conducting alkaline hydrothermal treatment on the surfaces for future orthopedic and dental metallic implants.