Double Acid Etching Research Articles

Wettability and adhesion of nanotubes applied to the surface of titanium implants by anodic oxidation

Background: A good implant surface is crucial for osseointegration. Many types are described in literature like double acid etching, SLA and anodization.

Differential inflammatory landscape stimulus during titanium surfaces obtained osteogenic phenotype.

Molecular mechanism governing inflammatory scenario in response to titanium (Ti)-nanotexturing surfaces needs to be better addressed. Thus, we subjected pre-osteoblast to different Ti-texturing surfaces, as follows: machined (Mac), double acid-etching (DAE), and nanoscaled hydroxyapatite-blasted titanium surface (nHA), considering the cells chronically responding either directly (when the cells were cultured onto the surfaces) or indirectly (when the cells were challenged with the conditioned medium by the surfaces), up to 10 days. Our results showed that there is a dynamic requirement of inflammatory-related genes activation in response to nHA by up expressing IL1ß, IL6, IL10, and IL33 (direct condition) and IL6, IL10, IL18 (indirect condition). Importantly, our data show that there is inflammasome involvement, once NLRP3, ASC1, and CASP1 genes were also required. As we found a strong signal of IL10, an anti-inflammatory cytokine, we further investigated Sonic Hedgehog (Shh) signaling cascade. Surprisingly, Shh ligand and Smoothened (Smo) genes were up-modulated in response to nHA, while Patched (Ptc) was down-modulated. Finally, an interactome was built using bioinformatics reinforcing Shh signaling cascade on modulating IL10 transcripts by Src mediating this process and this prevalence of anti-inflammatory picture might explain the low profile of RANKL transcripts in response to nHA, compromising the osteoclastogenesis surrounding the implants. Taking our results into account, our data show that the inflammatory landscape promoted by nHA is strictly modulated by Shh signaling promoted anti-inflammatory pathways. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1597-1604, 2019.

An Evaluation of Er:YAG Laser in an Intact Enamel Treatment on Bonding to the Resin Cement Compared to Four Traditional Techniques

Evaluation of the bond strength of the resin cement after enamel conditioning with erbium-doped yttrium aluminum garnet laser compared to other four different techniques. The study consisted of 50 enamel specimens excluded from the smooth surfaces of newly extracted human 3rd molars. The specimens were randomly divided into five groups in terms of the enamel treatment technique. Each group (n = 10) was conditioned differently by bevel and acid etching group (I), acid etching technique group (II), double acid etching technique group (III), air abrasion followed by acid etching group (IV), and Er:YAG laser followed by acid etching group (V). After enamel treatment, a resin cylinder was installed using split Teflon matrix on each enamel specimen. Then the specimens were exposed to a shear strength device, and shear force was applied. The results were recorded with Newton. The required data were collected and statistically analyzed. A one-way ANOVA test was conducted to compare the five study groups using SPSS version 21 (p < 0.05). All groups showed high shear bond strength values ranging from 19.26 MPa (for group III) to 27.05 MPa (for group V). The enamel treatment with Er:YAG laser followed by acid etching gave the best results with significant differences compared to the other groups. Within the limitations of the present study, it can be concluded that the combination between the Er:YAG laser and the acid etching enhances the bond strength of resin cement with the enamel. The use of Er:YAG laser followed by acid etching can be a successful technique for enamel conditioning and the results showed their superiority over the other groups.

Effect of Different Morphology of Titanium Surface on the Bone Healing in Defects Filled Only with Blood Clot: A New Animal Study Design.

Background The objective of the present histologic animal study was to analyze whether roughness of the titanium surface can influence and/or stimulate the bone growth in defects filled with the blood using a rabbit tibia model. Materials and Methods Forty sets (implant and abutment), dental implant (3.5 mm in diameter and 7 mm in length) plus healing abutment (2.5 mm in diameter), were inserted in the tibiae of 10 rabbits. Moreover, twenty titanium discs were prepared. The abutment and discs were treated by 4 different methods and divided into 4 groups: (group A) machined abutments (smooth); (group B) double acid etching treatment; (group C) treatment with blasting with particles of aluminum oxide blasted plus acid conditioning; (group D) treatment with thorough blasting with particles of titanium oxide plus acid conditioning. The discs were used to characterize the surfaces by a profilometer and scanning electronic microscopy. Results After 8 weeks, the new bone formation around the sets of the samples was analyzed qualitatively and quantitatively in relation to bone height from the base of the implant and presence of osteocytes. Group C (1.50±0.20 mm) and group D (1.62±0.18 mm) showed bone growth on the abutment with higher values compared to group A (0.94±0.30 mm) and group B (1.19±0.23 mm), with significant difference between the groups (P < 0.05). In addition, osteocyte presence was higher in groups with surface treatment related to machined (P < 0.05). Conclusions Within the limitations of the present study, it was possible to observe that there is a direct relationship between the roughness present on the titanium surface and the stimulus for bone formation, since the presence of larger amounts of osteocytes on SLA surfaces evidenced this fact. Furthermore, the increased formation of bone tissue in height demonstrates that there is an important difference between the physical and chemical methods used for surface treatment.

Characterization of chemically treated Ti-Zr system alloys for dental implant application

Materials and surfaces developed for dental implants need to withstand degradation processes that take place in the oral cavity. Therefore, the aim of the study was to develop and evaluate the topographical, mechanical, chemical, electrochemical and biological properties of Ti-xZr alloys (x = 5, 10, and 15 wt%) with two surface features (machined and double acid etched). Commercially pure titanium (cpTi) and Ti-6Al-4V alloy were used as controls. Surface characterization was performed using dispersive energy spectroscopy, X-ray diffraction, scanning electron microscopy, atomic force microscopy, profilometry and surface energy. The mechanical properties were assessed using Vickers microhardness, elastic modulus and stiffness. The electrochemical behavior analysis was conducted in a body fluid solution (pH 7.4). In addition, MC3T3-E1 cells were used to determine the impact of material and surface treatment on cell morphology by SEM analysis. Data were analyzed by two-way ANOVA and Bonferroni test (α = 0.05). Ti-Zr alloys showed lower surface roughness, elastic modulus and stiffness, as well as higher hardness and surface energy when compared to cpTi. Ti-Zr system increased the polarization resistance values and significantly decreased the capacitance, corrosion current density (icorr), and passivation current density (ipass) values. The acid treatment increased the resistance and corrosion potential of the oxide layer. SEM data analysis demonstrated that Ti-Zr alloys displayed normal cell attachment/spreading and slightly changed cell morphology in the double etched surface. In conclusion, Zr addition and surface treatment altered surface, mechanical, biological and electrochemical properties of Ti material.

Surface Modification of Ti-35Nb-10Ta-1.5Fe by the Double Acid-Etching Process.

Surface topography and composition influence the osteoblastic proliferation and osseointegration rates, which favor the biomechanical stability of bone anchoring and implants. In recent years, beta titanium alloys have been developed, and are composed of biocompatible elements, have low elastic modulus, high corrosion resistance, and mechanical properties to improve the long performance behavior of biomaterials. In the present research, the influence of the acid-etching process was studied in Ti6Al4V ELI and Ti35Nb10Ta1.5Fe. Samples were etched in a two-step acid treatment. Surface roughness parameters were quantified under a confocal microscope, topography was studied by scanning electron microscopy, and surface composition was analyzed with energy dispersive X-ray spectroscopy. The results revealed that the two-step acid treatment changes the topography of the β alloy, increases the surface area, and changes the chemical composition of the surface. Two differentiated regions were identified in the Ti35Nb10Ta1.5Fe alloy after the acid-etching process: The α + β region with higher values of mean roughness due to the lower chemical resistance of this region; and the β region with lower values of roughness parameters.

Evaluation of a Titanium Surface Treated with Hydroxyapatite Nanocrystals on Osteoblastic Cell Behavior: An In Vitro Study.

In the context of macrostructural and microstructural modifications to the design of dental implants, surface topography changes with different treatments have the purpose of accelerating bone formation. The aim of this study was to evaluate in vitro the influence of aggregated hydroxyapatite nanocrystals to surfaces treated with double acid etching (Nano) on osteoblastic cell behavior compared with a conventional double acid-etched surface (DE). Commercially pure Grade 4 titanium discs (6 × 2 mm) were selected, and both cell proliferation and viability were assessed at 24, 48, and 72 hours using Trypan blue vital dye and MTT, respectively. The expression of type I collagen and osteopontin on such surfaces was evaluated using ELISA. Immunostaining for fibronectin was also performed. Quantitative data were analyzed statistically using two-way analysis of variance (ANOVA) followed by Bonferroni post-test with a 5% significance level. The results showed that in all evaluated time periods, cells expressed fibronectin on both surfaces. The cells presented greater morphologic spreading on the Nano surface when compared with the conventional DE surface in all assessed times. Increased cell proliferation and viability were detected in the Nano surface (P < .05) when compared with the conventional DE surface, especially after 72 hours. Osteopontin expression was higher after 24 hours in the Nano surface when compared with the conventional DE surface (P < .05). For type I collagen, a higher expression was observed with the Nano surface than with the DE surface, again after 72 hours (P < .05). This in vitro study showed that the treated Nano surface tested promoted increased cell proliferation and viability when compared with the control surface. Additionally, increased cell spreading as well as type I collagen and osteopontin secretion were observed, favoring the early events of osseointegration.

Double acid etching treatment of dental implants for enhanced biological properties.

The topographical features on the surface of dental implants have been considered as a critical parameter for enhancing the osseointegration of implants. In this work, we proposed a surface obtained by a combination of shot blasting and double acid etching. The double acid etching was hypothesized to increase the submicron topography and hence further stimulate the biological properties of the titanium implant. The topographical features (surface roughness and real surface area), wettability and surface chemical composition were analyzed. The results showed that the proposed method produced a dual roughness, mainly composed of randomly distributed peaks and valleys with a superimposed nanoroughness, and hence with an increased specific surface area. Despite the fact that the proposed method does not introduce significant chemical changes, this treatment combination slightly increased the amount of titanium available on the surface, reducing potential surface contaminants. Furthermore, the surface showed increased contact angle values demonstrating an enhanced hydrophobicity on the surface. The biological behavior of the implants was then assessed by culturing osteoblast-like cells on the surface, showing enhanced osteoblast adhesion, proliferation and differentiation on the novel surface. Based on these results, the described surface with dual roughness obtained by double acid etching may be a novel route to obtain key features on the surface to enhance the osseointegration of the implant. Our approach is a simple method to obtain a dual roughness that mimics the bone structure modified by osteoclasts and increases surface area, which enhances osseointegration of dental implants.

Osseointegration of Titanium Implants With Different Rough Surfaces: A Histologic and Histomorphometric Study in an Adult Minipig Model.

Many chemical and physical modifications of titanium surfaces were introduced, aiming at improving surface bioactivity, but few comparative evidence exists. To evaluate histologically in minipigs the osseointegration of implants made of commercially pure (CP) titanium or titanium alloy, treated by different roughening procedures. Three sandblasted acid-etched (SA) surfaces, 2 anodized (AN), and 1 double acid-etched (DAE) were compared. Surface microtopography was characterized with scanning electron microscope; surface element composition was also assessed. One implant per group was inserted in each proximal tibia of 2 minipigs. Three months after healing, block biopsies were taken for histomorphometric analysis. Implant stability quotient (ISQ) was measured at insertion and before harvesting. The highest amount of cortical bone-implant contact was observed around SA implants and showed positive correlation with surface roughness. The greatest increase in ISQ was observed in CP-AN implants. In the medullary region, SA implants showed the best osteogenic response, whereas inflammatory cells were found around DAE and alloy-AN implants. SA surfaces were more osteogenic than anodized or dual acid-etched ones, although not significantly. Surface roughness affected osseointegration.

Chemical and topographic analysis of treated surfaces of five different commercial dental titanium implants

We present a detailed investigation of the surface characteristics of five commercial titanium implants with different surface finishing (double acid etching, anodization and incorporation of Ca/P, acid etching and deposition of Ca/P, hydroxyapatite-blasting, acid etching and Ca/P-blasting) produced by five different manufacturers. A set of experimental techniques were employed to study the surface chemical composition and morphology: XPS, XRD, SEM, EDS, and AFM. According to the implat manufacturers, the addition of Ca and P at the implant surface is a main feature of these implants (except the double acid etched implant, which was included for comparative purpose). However, the results showed a great discrepancy on the final amount of these elements on the implant surface, which suggests a different effectiveness of the employed surface finishing methods to fix those elements on the implant surface. Our results show that only the method used by the manufacturer of hydroxyapatite-blasting surface finished implants was efficient to produce a hydroxyapatite coating. This group also showed the highest roughness parameters.

Vitamin D and Bone Physiology: Demonstration of Vitamin D Deficiency in an Implant Osseointegration Rat Model

The patient population varies in nutritional deficiencies, which may confound the host response to biomaterials. The objective of this study was to evaluate the effect of a common deficiency of vitamin D on implant osseointegration in the rat model. Male Sprague-Dawley rats were maintained under the cessation of vitamin D intake and UV exposure. The serum levels of 1,25(OH)(2)D(3), 25 OHD(3), Ca, and P were determined. Miniature cylindrical Ti6Al4V implants (2-mm long, 1-mm diameter) were fabricated with double acid-etched (DAE) surface or modified DAE with discrete crystalline deposition (DCD) of hydroxyapatite nanoparticles. DAE and DCD implants were placed in the femurs of vitamin D-insufficient and control rats. After 14 days of healing, the femur-implant samples were subjected to implant push-in test and nondecalcified histology. The surfaces of recovered implant specimens after the push-in test were further evaluated by scanning electron microscopy (SEM). The decreased serum level of 25 OHD(3) demonstrated the establishment of vitamin D insufficiency in this model. The implant push-in test revealed that DAE and DCD implants in the vitamin D-insufficient group (15.94 +/- 8.20 N, n = 7; 15.63 +/- 3.96 N, n = 7, respectively) were significantly lower than those of the control group (24.99 +/- 7.92 N, n = 7, p < 0.05; 37.48 +/- 17.58 N, n = 7, p < 0.01, respectively). The transcortical bone-to-implant contact ratio (BIC) was also significantly decreased in the vitamin D-insufficient group. SEM analyses further suggested that the calcified tissues remaining next to the implant surface after push-in test appeared unusually fragmented. The effect of vitamin D insufficiency significantly impairing the establishment of Ti6Al4V implant osseointegration in vivo was unexpectedly profound. The outcome of Ti-based endosseous implants may be confounded by the increasing prevalence of vitamin D insufficiency in our patient population.

Assessing Double Acid-Etched Implants Submitted to Orthodontic Forces and Used as Prosthetic Anchorages in Partially Edentulous Patients

:The use of implants as anchorage for orthodontic forces seems to be a good alternative in partially edentulous patients needing orthodontic treatment. This study is aimed at assessing the performance and behavior of microtextured surface endosseous implants obtained by means of a double acid etching against orthodontic forces, as well as their adequacy to be used first as anchorage and later as fixtures for the definitive prosthesis.Materials and Methods: A total of 93 double acid-etched surface parallel wall implants (Osseotite® Implants, Implant Innovations Inc., Palm Beach, Florida, USA) were inserted in 38 partially edentulous patients prior to orthodontic treatment This was carried out by following two-stage surgery protocols in the maxilla as well as in the mandible.After a healing period of six months for the maxilla and four months for the mandible, the implants were used as anchorage for sliding, compression and traction orthodontic forces between 100 to 200 g by means of Ni-TI springs.Bone level and Resonance Frequency Analysis (RFA) were measured before and after the introduction of the orthodontics forces.Results: After removal of the orthodontics appliances, all the implants remained stabile and served as support for prosthetic replacement of missing teeth. The bone level showed no variationeven when a positive difference 0.02 ± 0.38mm was noticed. The RFA scored a significant difference (p≤ 0.03) between the initial Implant Stability Quotient (ISQ) values (66) and the final ones (68).Conclusions: These findings showed that Osseotite implants were able to support the orthodontic forces applied during this investigation, maintaining osseointegration without significant variation in bone level. Therefore, they can be used to support dental prosthesis once they have been used as orthodontic anchorage under the cited conditions.

Discrete deposition of hydroxyapatite nanoparticles on a titanium implant withpredisposing substrate microtopography accelerated osseointegration

We report here a new versatile method to deposit discrete hydroxyapatite(HA) nanoparticles on a titanium (Ti) implant with predisposing substratemicrotopography, which exhibited an unexpectedly robust biological effect.Commercially pure Ti substrates were treated with 3-aminopropyltriethoxysilane,on which HA nanoparticles (20 nm) were deposited and chemically bonded toTiO2. The HA deposition rate was linearly related to the treatment time and HA nanoparticleswere deposited on up to 50% of the substrate surface. As a result, the discrete deposition ofHA nanoparticles generated novel 20–40 nm nanotopography on the Ti substrate withmicrotopography that was smooth (turned) or roughened by double acid etching (DAE).The experimental implants with or without HA nanoparticles were surgically placed in ratfemur and an implant push-in test was performed after two weeks of healing. Thedeposition of HA nanoparticles on the DAE surface increased the mechanical withstandingload by 129% and 782% as compared to the control DAE and turned implants, respectively.Micro-computed tomography-based 3D bone morphometry revealed equivalentbone volumes around the DAE implant with or without HA nanoparticles. Thesedata suggest that the discrete deposition of HA nanoparticles accelerates theearly osseointegration process, likely through increased shear bonding strengths.