The Effect of Age of Titanium Dental Implants on Implant Survival and Marginal Bone Resorption: A 5-Year Retrospective Follow-Up Study.

It has been demonstrated that the osteoconductivity, hydrophilicity, and biological capacity of titanium decreases over time, and this phenomenon was described as the biological aging of titanium. The aim of this study was to evaluate whether the age of sand-blasted and acid-etched (SLA) titanium dental implants (duration from the production date until the date of dental implant surgery) affects marginal bone resorption and implant survival. This nonrandom convenience-sample retrospective pilot study was carried out in 200 implants of 64 patients. Radiographic measurements were performed on intraoral periapical radiographs. Implants were divided into 2 age groups; group 1 = 0-3 months and group 2 = 36-41 months. A P value < .05 was considered statistically significant. Of the implants, 41% (n = 82) were between 0 and 3 months old, and 59% (n = 118) were between 36 and 41 months old. All (n = 200) of the implants survived and maintained their function. The mean mesial marginal resorption measurement was 0.60 ± 0.65 mm, and the mean distal marginal resorption was 0.77 ± 1.07 mm. There was no statistically significant difference between the amount of mesial and distal marginal bone resorption according to implant age (P > .05). In SLA surface titanium implants with adequate initial primary stability and a 3-month osseointegration period before loading, biological aging of titanium did not affect implant survival and marginal bone resorption.

Mesenchymal stromal cell and osteoblast responses to oxidized titanium surfaces pre-treated with λ = 808 nm GaAlAs diode laser or chlorhexidine: in vitro study.

Preservation of implant biocompatibility following peri-implantitis treatments is a crucial issue in odontostomatological practice, being closely linked to implant re-osseointegration. Our aim was to assess the responses of osteoblast-like Saos2 cells and adult human bone marrow-mesenchymal stromal cells (MSCs) to oxidized titanium surfaces (TiUnite®, TiU) pre-treated with a 808 ± 10 nm GaAlAs diode laser operating in non-contact mode, in continuous (2 W, 400 J/cm2; CW) or pulsed (20 kHz, 7 µs, 0.44 W, 88 J/cm2; PW) wave, previously demonstrated to have a strong bactericidal effect and proposed as optional treatment for peri-implantitis. The biocompatibility of TiU surfaces pre-treated with chlorhexidine digluconate (CHX) was also evaluated. In particular, in order to mimic the in vivo approach, TiU surfaces were pre-treated with CHX (0.2%, 5 min); CHX and rinse; and CHX, rinse and air drying. In some experiments, the cells were cultured on untreated TiU before being exposed to CHX. Cell viability (MTS assay), proliferation (EdU incorporation assay; Ki67 confocal immunofluorescence analysis), adhesion (morphological analysis of actin cytoskeleton organization), and osteogenic differentiation (osteopontin confocal immunofluorescence analysis; mineralized bone-like nodule formation) analyses were performed. CHX resulted cytotoxic in all experimental conditions. Diode laser irradiation preserved TiU surface biocompatibility. Notably, laser treatment appeared even to improve the known osteoconductive properties of TiU surfaces. Within the limitations of an in vitro experimentation, this study contributes to provide additional experimental basis to support the potential use of 808 ± 10 nm GaAlAs diode laser at the indicated irradiation setting, in the treatment of peri-implantitis and to discourage the use of CHX.

Air atmospheric-pressure plasma-jet treatment enhances the attachment of human gingival fibroblasts for early peri-implant soft tissue seals on titanium dental implant abutments.

OBJECTIVE: Although dental implants are commonly used for tooth restoration, there is a lack of studies of treatment regimens for preventing extra-oral infection and decreasing osseointegration failures by establishing early peri-implant soft tissue seals on titanium dental implant abutments. In this study, air atmospheric-pressure plasma-jet (AAPPJ) treatment was applied to titanium disks to assay the potential for early peri-implant soft tissue seals on titanium dental implant abutment. MATERIALS AND METHODS: After titanium disks were treated with AAPPJ for 10 s at 250, 500, 1000 and 1500 sccm, surface analysis was performed; the control group received air only or no treatment. Human gingival fibroblasts (HGF) were seeded onto the specimens for evaluating cell attachment and proliferation and adherent-cell morphology was visualized via confocal microscopy. RESULTS: In AAPPJ-treated specimens, the water contact angle decreased according to increased flow rate. Oxygen composition increased in XPS, but no topographical changes were detected. The effect of AAPPJ treatment at 1000 sccm was apparent 2 mm from the treated spot, with a 20% increase in early cell attachment and proliferation. Adherent HGF on AAPPJ-treated specimens displayed a stretched phenotype with more vinculin formation than the control group. CONCLUSIONS: Within the limitations of this study, the results indicate that AAPPJ treatment may enhance the early attachment and proliferation of HGF for establishing early peri-implant soft tissue seals on titanium dental implant abutments with possible favorable effects of osseointegration of dental implant.

Alendronate as Bioactive Coating on Titanium Surfaces: An Investigation of CaP-Alendronate Interactions.

The surface modification of dental implants plays an important role in establishing a successful interaction of the implant with the surrounding tissue, as the bioactivity and osseointegration properties are strongly dependent on the physicochemical properties of the implant surface. A surface coating with bioactive molecules that stimulate the formation of a mineral calcium phosphate (CaP) layer has a positive effect on the bone bonding process, as biomineralization is crucial for improving the osseointegration process and rapid bone ingrowth. In this work, the spontaneous deposition of calcium phosphate on the titanium surface covered with chemically stable and covalently bound alendronate molecules was investigated using an integrated experimental and theoretical approach. The initial nucleation of CaP was investigated using quantum chemical calculations at the density functional theory (DFT) level. Negative Gibbs free energies show a spontaneous nucleation of CaP on the biomolecule-covered titanium oxide surface. The deposition of calcium and phosphate ions on the alendronate-modified titanium oxide surface is governed by Ca2+-phosphonate (-PO3H) interactions and supported by hydrogen bonding between the phosphate group of CaP and the amino group of the alendronate molecule. The morphological and structural properties of CaP deposit were investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopy. This integrated experimental-theoretical study highlights the spontaneous formation of CaP on the alendronate-coated titanium surface, confirming the bioactivity ability of the alendronate coating. The results provide valuable guidance for the promising forthcoming advancements in the development of biomaterials and surface modification of dental implants.

Surface Modification and Functionalities for Titanium Dental Implants.

Dental implants have become the mainstream strategy for oral restoration, and implant materials are the most important research hot spot in this field. So far, Ti implants dominate all kinds of implants. The surface properties of the Ti implant play decisive roles in osseointegration and antibacterial performance. Surface modifications can significantly change the surface micro/nanotopography and composition of Ti implants, which will effectively improve their hydrophilicity, mechanical properties, osseointegration performance, antibacterial performance, etc. These optimizations will thus improve implant success and service life. In this paper, the latest surface modification techniques of Ti dental implants are systematically and comprehensively reviewed. The various biomedical functionalities of surface modifications are discussed in-depth. Finally, a profound comment on the challenges and opportunities of this frontier is proposed, and the most promising directions for the future were explored.

TyroFill-Titanium Implant Constructs for the Coordinated Repair of Rabbit Mandible and Tooth Defects.

Currently used methods to repair craniomaxillofacial (CMF) bone and tooth defects require a multi-staged surgical approach for bone repair followed by dental implant placement. Our previously published results demonstrated significant bioengineered bone formation using human dental pulp stem cell (hDPSC)-seeded tyrosine-derived polycarbonate scaffolds (E1001(1K)-bTCP). Here, we improved upon this approach using a modified TyroFill (E1001(1K)/dicalcium phosphate dihydrate (DCPD)) scaffold-supported titanium dental implant model for simultaneous bone-dental implant repair. TyroFill scaffolds containing an embedded titanium implant, with (n = 3 each time point) or without (n = 2 each time point) seeded hDPCs and Human Umbilical Vein Endothelial Cells (HUVECs), were cultured in vitro. Each implant was then implanted into a 10 mm full-thickness critical-sized defect prepared on a rabbit mandibulee. After 1 and 3 months, replicate constructs were harvested and analyzed using Micro-CT histological and IHC analyses. Our results showed significant new bone formation surrounding the titanium implants in cell-seeded TyroFill constructs. This study indicates the potential utility of hDPSC/HUVEC-seeded TyroFill scaffolds for coordinated CMF bone-dental implant repair.

Surface modifications of titanium dental implants with strontium eucommia ulmoides to enhance osseointegration and suppress inflammation.

BACKGROUND: Titanium (Ti) is now widely used as implant material due to its excellent mechanical properties and superior biocompatibilities, while its inert bioactivities might lead to insufficient osseointegration, and limit its performance in dental applications. METHODS: We introduced a robust and simple approach of modifying titanium surfaces with polysaccharide complexes. Titanium samples were subjected to hydrothermal treatment to create a uniform porous structure on the surface, followed by coating with a bioinspired and self-assembly polydopamine layer. Strontium Eucommia Ulmoides Polysaccharide (EUP-Sr) complexes are then introduced to the polydopamine-coated porous titanium. Multiple morphological and physiochemical characterizations are employed for material evaluation, while cell proliferation and gene expression tests using macrophages, primary alveolar bone osteoblasts, and vascular endothelial cells are used to provide an overall insight into the functions of the product. The significances of statistical differences were analyzed using student's t-test. RESULTS: Microscopic and spectrometric characterizations confirmed that the Ti surface formed a porous structure with an adequate amount of EUP-Sr loading. The attachment was attributed to hydrogen bonding between the ubiquitous glycosidic linkage of the polysaccharide complex and the ring structure of polydopamine, yet the loaded EUP-Sr complex can be gradually released, consequently benefiting the neighboring microenvironment. Cell experiments showed no cytotoxicity of the material, and the product showed promising anti-inflammation, osseointegration, and angiogenesis properties, which were further confirmed by in vivo evaluations. CONCLUSION: We believe the EUP-Sr modified titanium implant is a promising candidate to be used in dental applications with notable osteoimmunomodulation and angiogenesis functions. And the novel technique proposed in this study would benefit the modification of metal/inorganic surfaces with polysaccharides for future research.

Bone Quantification Around Chitosan-Coated Titanium Dental Implants: A Preliminary Study by Micro-CT Analysis in Jaw of a Canine Model.

Surface treatments of Ti in the dental implant industry are performed with the aim of in-creasing its bioactivity and osseointegration capacity. Chitosan (Cht) is a polysaccharide that has been proposed as a promising biomaterial in tissue engineering and bone regeneration, due to its ability to stimulate the recruitment and adhesion of osteogenic progenitor cells. The aim of our preliminary study was to evaluate, by micro-computed tomography (micro-CT), the osseointegration and bone formation around Cht-coated implants and to compare them with conventional surface-etched implants (SLA type). Four im-plants (8.5 mm length × 3.5 mm Ø) per hemiarch, were inserted into the jaws of five dogs, divided into two groups: chitosan-coated implant group (ChtG) and control group (CG). Twelve weeks after surgery, euthanasia was performed, and sectioned bone blocks were obtained and scanned by micro-CT and two bone parameters were measured: bone in contact with the implant surface (BCIS) and peri-implant bone area (PIBA). For BCIS and PIBA statistically significant values were obtained for the ChtG group with respect to CG (p = 0.005; p = 0.014 and p < 0.001 and p = 0.002, respectively). The results, despite the limitations, demonstrated the usefulness of chitosan coatings. However, studies with larger sample sizes and adequate experimental models would be necessary to confirm the results.

Surface Functionalisation of Dental Implants with a Composite Coating of Alendronate and Hydrolysed Collagen: DFT and EIS Studies.

The success of the osseointegration process depends on the surface characteristics and chemical composition of dental implants. Therefore, the titanium dental implant was functionalised with a composite coating of alendronate and hydrolysed collagen, which are molecules with a positive influence on the bone formation. The results of the quantum chemical calculations at the density functional theory level confirm a spontaneous formation of the composite coating on the titanium implant, ∆G*INT = -8.25 kcal mol-1. The combination of the results of X-ray photoelectron spectroscopy and quantum chemical calculations reveals the structure of the coating. The alendronate molecules dominate in the outer part, while collagen tripeptides prevail in the inner part of the coating. The electrochemical stability and resistivity of the implant modified with the composite coating in a contact with the saliva depend on the chemical nature of alendronate and collagen molecules, as well as their inter- and intramolecular interactions. The formed composite coating provides a 98% protection to the implant after the 7-day immersion in the artificial saliva. From an application point of view, the composite coating could effectively promote osseointegration and improve the implant's resistivity in contact with an aggressive environment such as saliva.

Endosseous Dental Implant Materials and Clinical Outcomes of Different Alloys: A Systematic Review.

In recent years, implantology has made significant progress, as it has now become a safe and predictable practice. The development of new geometries, primary and secondary, of new surfaces and alloys, has made this possible. The purpose of this review is to analyze the different alloys present on the market, such as that in zirconia, and evaluate their clinical differences with those most commonly used, such as those in grade IV titanium. The review, conducted on major scientific databases such as Scopus, PubMed, Web of Science and MDPI yielded a startling number of 305 results. After the application of the filters and the evaluation of the results in the review, only 10 Randomized Clinical Trials (RCTs) were included. Multiple outcomes were considered, such as Marginal Bone Level (MBL), Bleeding on Probing (BoP), Survival Rate, Success Rate and parameters related to aesthetic and prosthetic factors. There are currently no statistically significant differences between the use of zirconia implants and titanium implants, neither for fixed prosthetic restorations nor for overdenture restorations. Only the cases reported complain about the rigidity and, therefore, the possibility of fracture of the zirconium. Certainly the continuous improvement in these materials will ensure that they could be used safely while maintaining their high aesthetic performance.

Comparison of surface aspects of turned and anodized titanium dental implant, or abutment material for an optimal soft tissue integration.

Objectives: Soft tissue integration of dental implants lags behind natural biological integration of teeth mainly because of non-optimal surface features. Peri-implant infections resulting in loss of supporting bone jeopardize the success of implants. Our aim was to compare an anodized surface design with a turned one for a more optimal surface. Methods: Morphological and chemical structures of turned and anodized Ti surfaces (grade 5: Ti6Al4V) discs were examined by scanning electron microscopy (SEM-EDS), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM). The hydrophilic or hydrophobic features of the surfaces were determined by dynamic contact angle measurement. Results: SEM and AFM revealed significant differences in the morphology and roughness (Ra) of the samples. Anodized discs presented a granular structure, while turned ones had circular grooves. The roughness was significantly higher for the anodized samples compared to the turned ones. XPS and EDS confirmed typical elements for both Ti6Al4V samples. Due to anodization, the amount of Ti (IV) had increased and Ti (III) had decreased in the thicker oxide layer. Anodized samples resulted in a more hydrophilic surface than the turned ones. Significance: The results suggest that the tested anodized samples present optimal surface characteristics to be used as abutment material for an optimal soft tissue integration.

Systematic Review and Meta-Analysis of the Effectiveness of Calcium-Phosphate Coating on the Osseointegration of Titanium Implants.

Ca-P coatings on Ti implants have demonstrated good osseointegration capability due to their similarity to bone mineral matter. Three databases (PubMed, Embase, and Web of Science) were searched electronically in February 2021 for preclinical studies in unmodified experimental animals, with at least four weeks of follow-up, measuring bone-to-implant contact (BIC). Although 107 studies were found in the initial search, only eight experimental preclinical studies were included. Adverse events were selected by two independent investigators. The risk of bias assessment of the selected studies was evaluated using the Cochrane Collaboration Tool. Finally, a meta-analysis of the results found no statistical significance between implants coated with Ca-P and implants with etched conventional surfaces (difference of means, random effects: 5.40; 99% CI: -5.85, 16.65). With the limitations of the present review, Ca-P-coated Ti surfaces have similar osseointegration performance to conventional etched surfaces. Future well-designed studies with large samples are required to confirm our findings.

A chair-side plasma treatment system for rapidly enhancing the surface hydrophilicity of titanium dental implants in clinical operations.

PURPOSE: In order to promote osseointegration and shorten the healing time after dental implant operations, this study was conducted to develop a chair-side plasma treatment system in which Ti implants were used as a coaxial internal electrode to rapidly enhance their surface hydrophilicity. METHODS: Surface hydrophilicity was evaluated by measurement of the water contact angle and the defined wetting time. Changes in temperature and chemical composition were analyzed using infrared thermal imaging and X-ray photoelectron spectroscopy (XPS), respectively. The biocompatibility of the treated implants was examined in an animal experiment. RESULTS: A marked improvement of hydrophilicity was demonstrated by a decrease in the water contact angle of the treated implant to 0° and wetting of the whole surface within 3 s of water contact. The Ti implant hydrophilization mechanism was explained as a decrease in the degree of hydrocarbon contamination. The surface temperature of the treated implant was close to that of the human body, and good osseointegration was observed in the in vivo experiment. CONCLUSION: The plasma treatment system developed here is a promising chair-side procedure for rapidly enhancing the surface hydrophilicity of Ti implants in clinical operations without any need to consider the degradation of hydrophilicity caused by long-term storage.

A New Insight into Coating's Formation Mechanism Between TiO2 and Alendronate on Titanium Dental Implant.

Organophosphorus compounds, like bisphosphonates, drugs for treatment and prevention of bone diseases, have been successfully applied in recent years as bioactive and osseoinductive coatings on dental implants. An integrated experimental-theoretical approach was utilized in this study to clarify the mechanism of bisphosphonate-based coating formation on dental implant surfaces. Experimental validation of the alendronate coating formation on the titanium dental implant surface was carried out by X-ray photoelectron spectroscopy and contact angle measurements. Detailed theoretical simulations of all probable molecular implant surface/alendronate interactions were performed employing quantum chemical calculations at the density functional theory level. The calculated Gibbs free energies of (TiO2)10-alendronate interaction indicate a more spontaneous exergonic process when alendronate molecules interact directly with the titanium surface via two strong bonds, Ti-N and Ti-O, through simultaneous participation common to both phosphonate and amine branches. Additionally, the stability of the alendronate-modified implant during 7 day-immersion in a simulated saliva solution has been investigated by using electrochemical impedance spectroscopy. The alendronate coating was stable during immersion in the artificial saliva solution and acted as an additional barrier on the implant with overall resistivity, R ~ 5.9 MΩ cm2.

Effects of Different Divalent Cation Hydrothermal Treatments of Titanium Implant Surfaces for Epithelial Tissue Sealing.

The improvement of peri-implant epithelium (PIE) adhesion to titanium (Ti) may promote Ti dental implant stability. This study aims to investigate whether there is a positive effect of Ti hydrothermally treated (HT) with calcium chloride (CaCl2), zinc chloride (ZnCl2), and strontium chloride (SrCl2) on promoting PIE sealing. We analyzed the response of a rat oral epithelial cell (OEC) culture and performed an in vivo study in which the maxillary right first molars of rats were extracted and replaced with calcium (Ca)-HT, zinc (Zn)-HT, strontium (Sr)-HT, or non-treated control (Cont) implants. The OEC adhesion on Ca-HT and Zn-HT Ti plates had a higher expression of adhesion proteins than cells on the Cont and Sr-HT Ti plates. Additionally, the implant PIE of the Ca-HT and Zn-HT groups revealed better expression of immunoreactive laminin-332 (Ln-322) at 2 weeks after implantation. The Ca-HT and Zn-HT groups also showed better attachment at the implant-PIE interface, which inhibited horseradish peroxidase penetration. These results demonstrated that the divalent cations of Ca (Ca2+) and Zn (Zn2+)-HT improve the integration of epithelium around the implant, which may facilitate the creation of a soft barrier around the implant to protect it from foreign body penetration.

Accuracy of Edentulous Computer-Aided Implant Surgery as Compared to Virtual Planning: A Retrospective Multicenter Study.

PURPOSE: To evaluate the accuracy of computer-aided dental implant positions obtained with mucosal-supported templates as compared to Three-Dimensional (3D) planning. MATERIALS AND METHODS: One-hundred implants were inserted into 14 edentulous patients using the All-on-4/6 protocol after surgical virtual planning with RealGUIDE, 3DIEMME, and Geomagic software. After 6 months, three-dimensional neck (V) and apex (S) spatial coordinates of implants and angle inclination displacements as compared to virtual plans were evaluated. RESULTS: The S maxilla coordinates revealed a significant discrepancy between clinical and virtual implant positions (p-value = 0.091). The V coordinates showed no significant differences (p-value = 0.71). The S (p-value = 0.017) and V (p-value = 0.038) mandible coordinates showed significant discrepancies between the clinical and virtual positions of the screws. Implant evaluation showed a 1-mm of the horizontal deviation in the V point and a 1.6-mm deviation in the S point. A mean 5° angular global deviation was detected. The multivariate permutation test of the S (p-value = 0.02) confirmed the difference. Greater errors in the mandible were detected as compared to the maxilla, and a higher S discrepancy was found in the posterior jaw compared to the anterior section of both the mandible and maxilla. CONCLUSIONS: Computer-aided surgery with mucosal-supported templates is a predictable procedure for implant placement. Data showed a discrepancy between the actual dental implant position as compared to the virtual plan, but this was not statistically significant. However, the horizontal and angle deviations detected indicated that flap surgery should be used to prevent implant positioning errors due to poor sensitivity and accuracy in cases of severe jaw atrophy.

General review of titanium toxicity.

BACKGROUND: Titanium is a commonly used inert bio-implant material within the medical and dental fields. Although the use of titanium is thought to be safe with a high success rate, in some cases, there are rare reports of problems caused by titanium. In most of these problematic reports, only individual reports are dominant and comprehensive reporting has not been performed. This comprehensive article has been prepared to review the toxicity of titanium materials within the medical and dental fields. METHODS: We used online searching tools including MEDLINE (PubMed), Embase, Cochrane Library, and Google Scholar by combining keywords such as "titanium implant toxicity," "titanium implant corrosion," "titanium implant allergy," and "yellow nail syndrome." Recently updated data has been collected and compiled into one of four categories: "the toxicity of titanium," "the toxicity of titanium alloys," "the toxicity of titanium implants," and "diseases related to titanium." RESULTS: Recent studies with regard to titanium toxicity have been increasing and have now expanded to the medical field in addition to the fields of environmental research and basic science. Problems that may arise in titanium-based dental implants include the generation of titanium and titanium alloy particles and ions deposited into surrounding tissues due to the corrosion and wear of implants, resulting in bone loss due to inflammatory reactions, which may lead to osseointegration failure of the dental implant. These titanium ions and particles are systemically deposited and can lead to toxic reactions in other tissues such as yellow nail syndrome. Additionally, implant failure and allergic reactions can occur due to hypersensitivity reactions. Zirconia implants can be considered as an alternative; however, limitations still exist due to a lack of long-term clinical data. CONCLUSIONS: Clinicians should pay attention to the use of titanium dental implants and need to be aware of the problems that may arise from the use of titanium implants and should be able to diagnose them, in spite of very rare occurrence. Within the limitation of this study, it was suggested that we should be aware the rare problems of titanium toxicity.

Enhanced antimicrobial activity of naturally derived bioactive molecule chitosan conjugated silver nanoparticle against dental implant pathogens.

Various metal coated implants have been tested against dental pathogens which causes increased biofilm formation and lead to failure of dental implants. The possibility of using nanoparticle together with native biomolecules to enhance the activity of such bioactive compound is also in progress. In this study we tested the efficacy of Ag conjugated chitosan nanoparticles as a prospective coating material of titanium dental implants. Known bioactive molecule chitosan was extracted from A. flavus Af09 and conjugated with Ag nanoparticle. Fully characterized Ag-chitosan nanoparticle had a sound inhibitory effect on the growth of two major dental pathogens S. mutans and P. gingivalis. It not only inhibits the adhesion of these two tested bacteria but also able to reduce the biofilm formation. Apart from this, nanoparticle was also able to inhibit the QS production in bacteria tested in this study. Naturally extracted chitosan has been known for its antibacterial activity for a different group of bacteria. Nanoparticles are the good option to enhance the biocompatibility. No cell cytotoxicity of nanoparticle indicates its biocompatibility and coating of titanium dental implants with Ag-chitosan may have an added advantage on the corrosion resistance of dental implants and also augments the passivating effect of these implants.

Zirconia in dental implantology: A review.

BACKGROUND: Titanium has been the most popular material of choice for dental implantology over the past few decades. Its properties have been found to be most suitable for the success of implant treatment. But recently, zirconia is slowly emerging as one of the materials which might replace the gold standard of dental implant, i.e., titanium. MATERIALS AND METHODS: Literature was searched to retrieve information about zirconia dental implant and studies were critically analyzed. PubMed database was searched for information about zirconia dental implant regarding mechanical properties, osseointegration, surface roughness, biocompatibility, and soft tissue health around it. The literature search was limited to English language articles published from 1975 to 2015. RESULTS: A total of 45 papers met the inclusion criteria for this review, among the relevant search in the database. CONCLUSION: Literature search showed that some of the properties of zirconia seem to be suitable for making it an ideal dental implant, such as biocompatibility, osseointegration, favourable soft tissue response and aesthetics due to light transmission and its color. At the same time, some studies also point out its drawbacks. It was also found that most of the studies on zirconia dental implants are short-term studies and there is a need for more long-term clinical trials to prove that zirconia is worth enough to replace titanium as a biomaterial in dental implantology.

Three-dimensional and chemical changes on the surface of a 3-year clinically retrieved oxidized titanium dental implant.

OBJECTIVE: To report the main topographical features in the micro- and nano-scales and to assess implant chemical changes of the surface of a 3-year clinically retrieved oxidized titanium dental implant, and compare them with a similar, unused implant. MATERIALS AND METHODS: The surface of the oxidized titanium dental implants was assessed by surface electron microscopy (SEM) analysis at increasing magnifications. X-ray photoelectron spectroscopy (XPS) measurement was performed to analyze the implants surface chemistry. XPS spectra were acquired before and after sputtering with an Ar(+) ion etching of 3keV. RESULTS: With a length of 10-40µm, and a width of 0.05-0.1µm, numerous cracks were ubiquitous along the implant surfaces. Chimney-like structures formed micropores between 1 and 5µm, with up to 40% of them partially or totally broken in the retrieved implant. In relation to chemical composition, Ti and O were predominant in both the unused and in the retrieved implant. N was present in high concentrations (11.49at%) at the retrieved implant surface, in contrast with those observed for the unused implant (1.14at%). Also, C was present in higher concentrations in the retrieved implant surface, while drastically decreased following the sputter-cleaning process. CONCLUSION: While cracks were ubiquitous present from the manufacturing, broken chimney-like structures forming micropores in the clinically retrieved implant may be attributable to excessive mechanical friction forces during the insertion of the implant. Chemical composition of the implant surface may be subjected to changes because of the in vivo environment, with increase of N and C, and decrease of Ca and P.