Special Issue "Dental Implant Surface: Science and Technology"

A special issue of Coatings (ISSN 2079-6412).

Deadline for manuscript submissions: closed (20 December 2017).

Special Issue Editor

Guest Editor
Dr. James Kit-hon Tsoi Website E-Mail
Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong
Phone: +852-2859-0303
Fax: +852-2548-9464
Interests: nanocoating for dental biomaterials, anti-bacterial coating, process of clinical coating

Special Issue Information

Dear Colleagues,

Despite the years of success in dental implants, the key to continued progress is largely dependent on the surface that connects between the materials, such as resin-to-titanium and zirconia and bone-to-titanium. The science and technology involved in dental implants is different from the science involved in orthopaedic implants, because the dental implant is exposed to a harsh oral environment, particularly prone to bacterial adhesion (biofilm) and environental challenge (e.g., pH and temperature). Thus, designing a dental implant with high longevity is deemed to be a challenge of high complexity. Therefore, in this Special Issue, we would like to invite reviews and research articles that focus on the science and technology aspects of the dental implant surface, which is the most important and challenging to tweak for clinical success. In particular, the topic of interest includes, but is not limited to:

  • Surface characterization
  • Biological and materials interfacial contact
  • Surface modification
  • Surface chemistry/biology/physics
  • Titanium/Zirconia
  • Osseointegration and adhesion

Dr. James Kit-hon Tsoi
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Coatings is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Mechanical and Spectroscopic Analysis of Retrieved/Failed Dental Implants
Coatings 2017, 7(11), 201; https://doi.org/10.3390/coatings7110201 - 15 Nov 2017
Cited by 2
Abstract
The purpose of this study was to examine surface alterations and bone formation on the surface of failed dental implants (Straumann [ST] and TiUnite [TiUn]) removed due to any biological reason. In addition, failure analysis was performed to test mechanical properties. Dental implants [...] Read more.
The purpose of this study was to examine surface alterations and bone formation on the surface of failed dental implants (Straumann [ST] and TiUnite [TiUn]) removed due to any biological reason. In addition, failure analysis was performed to test mechanical properties. Dental implants (n = 38) from two manufacturers were collected and subjected to chemical cleaning. The presence of newly formed hydroxyapatite bone around failed implants was evaluated using micro-Raman spectroscopy. Scanning electron microscopy was used to identify surface defects. Mechanical testing was performed using a Minneapolis servo-hydraulic system (MTS) along with indentation using a universal testing machine and average values were recorded. A statistical analysis of mechanical properties was done using an unpaired t test, and correlation between observed defects was evaluated using Chi-square (p = 0.05). Apatite-formation was evident in both implants, but was found qualitatively more in the ST group. No significant difference was found in indentation between the two groups (p > 0.05). The percentage of “no defects” was significantly lower in the ST group (71%). Crack-like and full-crack defects were observed in 49% and 39% of TiUn. The ST group showed 11,061 cycles to failure as compared with 10,021 cycles in the TiUnite group. Implant failure mechanisms are complex with a combination of mechanical and biological reasons and these factors are variable with different implant systems. Full article
(This article belongs to the Special Issue Dental Implant Surface: Science and Technology)
Show Figures

Figure 1

Open AccessArticle
Characterization of Hydroxyapatite (HA) Sputtering Targets by APS Methods
Coatings 2017, 7(11), 197; https://doi.org/10.3390/coatings7110197 - 11 Nov 2017
Cited by 3
Abstract
Radio frequency (RF) sputtering is a potential medical device coating technology that is commercializable; however, a suitable commercialized target for sputtering the hydroxyapatite (HA) coating onto titanium medical devices is more important. Therefore, this study used three HA targets in conducting sputtering experiments [...] Read more.
Radio frequency (RF) sputtering is a potential medical device coating technology that is commercializable; however, a suitable commercialized target for sputtering the hydroxyapatite (HA) coating onto titanium medical devices is more important. Therefore, this study used three HA targets in conducting sputtering experiments for HA films, which were manufactured in a laboratory by using three different processes: cold pressing and sintering (CPS), hot isostatic pressing (HIP), and atmospheric plasma spraying (APS). Subsequently, the sputtering performance of each type of target and the properties of the HA films were assessed to develop an appropriate process for modifying the surfaces of medical devices. The experimental results showed that the APS target, with a density of approximately 2.83 g/cm3, was suitable for use in HA sputtering. Additionally, the APS target could withstand a high discharge power over 300 W, whereas the CPS target could nearly endure a power below 70 W. The APS target, with Ca/P ratio of 2.401, consisted of a combination of HA, α-tricalcium phosphate (α-TCP), β-TCP, and tetracalcium phosphate phases (TTCP). In addition to being able to perform at a high sputtering power of more than 300 W, the APS target achieved a higher deposition rate than did the CPS target. This study shows that the processing technology used for the APS target is a potential method for applying HA sputtering for the surface modification of artificial aggregates. Full article
(This article belongs to the Special Issue Dental Implant Surface: Science and Technology)
Show Figures

Figure 1

Open AccessArticle
Chitosan Coating on Silica-Modified Polymethyl Methacrylate for Dental Applications
Coatings 2017, 7(10), 168; https://doi.org/10.3390/coatings7100168 - 13 Oct 2017
Cited by 2
Abstract
Chitosan is a cationic natural polymer that is widely used as a topical dressing in wound management. Temporary coatings of removable denture bases with chitosan might be useful as supportive treatment in oral medicine. The aim of this study was to analyze the [...] Read more.
Chitosan is a cationic natural polymer that is widely used as a topical dressing in wound management. Temporary coatings of removable denture bases with chitosan might be useful as supportive treatment in oral medicine. The aim of this study was to analyze the thickness, uniformity, and adhesive strength of chitosan coatings on simulated denture bases made from polymethyl methacrylate (PMMA). According to a standardized protocol, 20 PMMA cylinders (13 mm diameter, 5 mm in height) as well as 20 cubes (a = 25 mm) with intaglio U-shaped profiles were manufactured to simulate average sized alveolar ridges. Cylinders as well as cubes were divided into four test series with n = 5 each. After sandblasting with silica-modified alumina, one frontal surface of the PMMA cylinders and the intaglio surfaces of the U-shaped profiles was coated with chitosan acetate solution according to the following protocols: one layer of 2% chitosan acetate solution (test series I), one layer of 4% chitosan acetate solution (test series II), two layers of 2% chitosan acetate solution (test series III), and two layers of 4% chitosan acetate solution (test series IV). After drying and neutralization with NaOH, each cube was cut transversely and the coating thickness across the U-shaped profile assessed with a light microscope. Adhesive strength was evaluated by simulated tooth brushing and the loss of chitosan coating was evaluated qualitatively. Statistical analysis used Friedman ANOVA test for dependent samples and Kruskal-Wallis test for independent samples, post-hoc Dunn’s test (p < 0.05), and binomial test (p = 0.05). The mean chitosan coating thicknesses in the depth of the U-profiles were 71 µm (test series I), 77 µm (test series II), 121 µm (test series III), and 517 µm (test series VI). The thickness continuously decreased with rising angulation of the U-profile side walls. In test series I, the chitosan coating thickness significantly dropped above a 30° angulation of the U-profile side walls. In test series II to IV, the chitosan thickness drop was not statistically significant at angulations of 30° and 60°, but was at 90° angulation of the U-profile side walls. Adhesion strength was rated fair to good and did not differ significantly among the four test series. The coating technique described revealed chitosan layers with overall good adhesion strength but differing thicknesses. Coatings with one or two layers of 4% chitosan acetate solution allowed a relatively uniform chitosan thickness and thus might be usable in oral medicine. Full article
(This article belongs to the Special Issue Dental Implant Surface: Science and Technology)
Show Figures

Figure 1

Open AccessArticle
Influence of Grit-Blasting and Hydrofluoric Acid Etching Treatment on Surface Characteristics and Biofilm Formation on Zirconia
Coatings 2017, 7(8), 130; https://doi.org/10.3390/coatings7080130 - 20 Aug 2017
Cited by 5
Abstract
The objective of this study was to investigate the effect of hydrofluoric acid etching treatment on the surface characteristics of zirconia and Streptococcus sanguinis (S. sanguinis) and Porphyromonas gingivalis (P. gingivalis) biofilm formation on zirconia. Zirconia specimens were prepared [...] Read more.
The objective of this study was to investigate the effect of hydrofluoric acid etching treatment on the surface characteristics of zirconia and Streptococcus sanguinis (S. sanguinis) and Porphyromonas gingivalis (P. gingivalis) biofilm formation on zirconia. Zirconia specimens were prepared with different treatments, including being polished with 1000-grit SiC abrasive paper as the control group (Group C), grit-blasted with 110 μm silica-coated alumina particles (Group GB), etched with 40% hydrofluoric acid for 25 min at 100 °C (Group HF), and grit-blasted with 110 μm silica-coated alumina particles and then etched with 40% hydrofluoric acid for 25 min at 100 °C (Group GBHF). The highest surface roughness values and hydrophilicity were shown in Group HF and Group GBHF. Scanning electron microscopy (SEM) showed that hydrofluoric acid can create a crater-like appearance on the zirconia surface. An energy-dispersive X-ray (EDX) analysis demonstrated similar element concentration (wt %) in Group C, Group HF, and Group GBHF, but not for Group GB with higher concentrations of Al and Si element. Colony forming unit (CFU) counts showed that a similar amount of S. sanguinis biofilm and significantly lower P. gingivalis biofilm were formed on zirconia surfaces in Group HF and Group GBHF compared to that in Group C after three days of bacteria culture (p < 0.05). These results indicate that hydrofluoric acid etching on zirconia may not increase S. sanguinis and P. gingivalis mature biofilm formation on zirconia. Full article
(This article belongs to the Special Issue Dental Implant Surface: Science and Technology)
Show Figures

Figure 1

Open AccessArticle
Characteristics of RF-Sputtered Thin Films of Calcium Phosphate on Titanium Dental Implants
Coatings 2017, 7(8), 126; https://doi.org/10.3390/coatings7080126 - 16 Aug 2017
Cited by 4
Abstract
Hydroxyapatite (HA) coatings on titanium have been investigated for many years, and have demonstrated advantageous biocompatibility in dental implants. Animal experiments have demonstrated that the biological response to plasma-sprayed HA-coated implants shows disadvantages in terms of adherence, thickness uniformity, and long-term osseointegration effects. [...] Read more.
Hydroxyapatite (HA) coatings on titanium have been investigated for many years, and have demonstrated advantageous biocompatibility in dental implants. Animal experiments have demonstrated that the biological response to plasma-sprayed HA-coated implants shows disadvantages in terms of adherence, thickness uniformity, and long-term osseointegration effects. Determining how to resolve the degradation problem of HA in the body by improving osseointegration and stability in alveolar bones has become an increasingly researched topic. The present study investigated the film characteristics and dissolution properties of calcium phosphate (CaP) coatings obtained by radio-frequency (RF) sputtering of a self-developed atmospheric plasma spray (APS) HA target. The experimental parameters varied, including RF power (60–250 W), sputtering time (15–120 min), and substrate roughness (0.4–4 μm). Analyses were conducted using synchrotron X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), white light interferometry, and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (EDS). EDS analysis showed that the Ca/P ratio increased as the discharge power was increased. The analysis results also showed that a lower surface roughness resulted in higher crystallinity, because a larger surface-free energy was attained during sputtering. In-plane texturing has been proven when HA films are sputtered onto substrates of varying roughness, within appropriate deposition parameters. FTIR analysis revealed the presence of the principal PO43- bonds in the deposited calcium phosphate films. The CaP films induced calcium phosphate precipitation when immersed in simulated body fluid (SBF), suggesting that, based on in vitro bioactive behavior, the proposed combined surface modification can be used in dental implants. Full article
(This article belongs to the Special Issue Dental Implant Surface: Science and Technology)
Show Figures

Figure 1

Open AccessArticle
Ti-SLActive and TiZr-SLActive Dental Implant Surfaces Promote Fast Osteoblast Differentiation
Coatings 2017, 7(7), 102; https://doi.org/10.3390/coatings7070102 - 15 Jul 2017
Cited by 1
Abstract
A primary goal in modern surface modification technology of dental implants is to achieve biocompatible surfaces with rapid but controlled healing which also allow health and longevity of implants. In order to realize all, understanding of osseointegration phenomena is crucial. Although Ti-SLA, Ti-SLActive [...] Read more.
A primary goal in modern surface modification technology of dental implants is to achieve biocompatible surfaces with rapid but controlled healing which also allow health and longevity of implants. In order to realize all, understanding of osseointegration phenomena is crucial. Although Ti-SLA, Ti-SLActive and TiZr-SLActive surfaces have been successfully used in clinical implantology and were shown to notably reduce the primary healing time, available in vitro studies are sparse and do not concern or explore the mechanism(s) involved in human osteoblast behavior on these surfaces. Ti-SLA, Ti-SLActive, TiZr-SLActive, Ti cp, Ticer and Cercon surfaces were used. Osteoblast proliferation, cell cluster formation, morphological changes, induction of autophagy, nitric oxide (NO), reactive oxygen species/reactive nitrogen species (ROS/RNS) formation, osteocalcin (OC), bone sialoprotein (BSP) and collagen type I (Col-1) affected by various surfaces were analyzed. These surfaces induced formation of mature osteoblasts caused by elevated oxidative stress (ROS) followed by overexpression of osteoblast maturation key molecule (NO), with different intensity however. These mature osteoblasts induced upregulation of OC, BSP and Col-1, activating PI3/Akt signalling pathway resulting in autophagy, known as an important process in differentiation of osteoblast cells. Additional distinctive subpopulation identified on Ticer, Ti-SLA (after 5 days), Ti-SLActive and TiZr-SLActive surfaces (after 2 days) were forming cell clusters, essential for bone noduli formation and mineralisation. The results suggest that Ti- and TiZr-SLActive possess advanced properties in comparison with Ticer and Ti-SLA manifested as accelerated osteoblast differentiation. These effects could explain already known fast osseointegration of these surfaces in vivo. Full article
(This article belongs to the Special Issue Dental Implant Surface: Science and Technology)
Show Figures

Figure 1

Back to TopTop