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The goal of the study was to compare the surface characteristics of typical implant materials used in orthopedic surgery and traumatology, as these determine their successful biointegration. The morphological and chemical structure of Vortex plate anodized titanium from commercially pure (CP) Grade 2 Titanium (Ti2) is generally used in the following; non-cemented total hip replacement (THR) stem and cup Ti alloy (Ti6Al4V) with titanium plasma spray (TPS) coating; cemented THR stem Stainless steel (SS); total knee replacement (TKR) femoral component CoCrMo alloy (CoCr); cemented acetabular component from highly cross-linked ultrahigh molecular weight polyethylene (HXL); and cementless acetabular liner from ultrahigh molecular weight polyethylene (UHMWPE) (Sanatmetal, Ltd., Eger, Hungary) discs, all of which were examined. Visualization and elemental analysis were carried out by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Surface roughness was determined by atomic force microscopy (AFM) and profilometry. TPS Ti presented the highest R a value (25 ± 2 μm), followed by CoCr (535 ± 19 nm), Ti2 (227 ± 15 nm) and SS (170 ± 11 nm). The roughness measured in the HXL and UHMWPE surfaces was in the same range, 147 ± 13 nm and 144 ± 15 nm, respectively. EDS confirmed typical elements regarding the investigated prosthesis materials. XPS results supported the EDS results and revealed a high % of Ti 4+ on Ti2 and TPS surfaces. The results indicate that the surfaces of prosthesis materials have significantly different features, and a detailed characterization is needed to successfully apply them in orthopedic surgery and traumatology.

(1) Background: The retention of intraradicular posts is an important factor for the prognosis of endodontically treated teeth. The purpose of this study was to evaluate the push-out bond strength (PBS) of the posts relating to their diameter and region of the root. (2) Methods: A total of 40 premolar teeth (decoronated and root canal-filled) were divided into four groups (n = 10). After post-space preparation, different sizes (1.0, 1.2, 1.5, and 2.0 mm) of glass fiber posts were luted with resin cement into the root canals. After placement, 2 mm thick slices were cut from the roots according to their apical, middle, and coronal regions (n = 116). Push-out tests were carried out in a universal testing machine on each slice. A statistical evaluation of the data was applied. (3) Results: When comparing the diameter, the 2.0 mm posts had the highest PBS (111.99 ± 10.40 N), while the 1.0 mm posts had the lowest PBS (99.98 ± 8.05 N). Divided by the surface of the bonded area, the average PBS value was the highest for the 1.0 mm posts (18.20 ± 1.67 MPa) and the lowest for the 2.0 mm posts (12.08 ± 1.05 MPa). (4) Conclusions: Within the limitations of the study, when comparing the regions of the roots, no significant differences were found among the PBS values of the three regions ( p = 0.219). When comparing the diameters, significant differences were shown between the PBS values of the four groups ( p = 0.023 and p = 0.003, respectively).

Background: Navigated endodontics is a cutting-edge technology becoming increasingly more accessible for dental practitioners. Therefore, it is necessary to clarify the ideal technical parameters of this procedure to prevent collateral damage of the surrounding tissues. There is a limited number of studies available in published scientific literature referencing the possible collateral thermal damage due to high-speed rotary instruments used in guided endodontic drilling. The aim of our study was to investigate the different drilling parameters and their effect upon the temperature elevations measured on the outer surface of teeth during guided endodontic drilling., Methods: In our in vitro study, 72 teeth with presumably narrow root canals were prepared using a guided endodontic approach through a 3D-printed guide. Teeth were randomly allocated into six different test groups consisting of 12 teeth each, of which, four parameters affecting temperature change were investigated: (a) access cavity preparation prior to endodontic drilling, (b) drill speed, (c) cooling, and (d) cooling fluid temperature. Temperature changes were recorded using a contact thermocouple electrode connected to a digital thermometer., Results: The highest temperature elevations (14.62 °C ± 0.60 at 800 rpm and 13.76 °C ± 1.24 at 1000 rpm) were recorded in the groups in which drilling was performed without prior access cavity preparation nor without a significant difference between the different drill speeds (p = 0.243). Access cavity preparation significantly decreased temperature elevations (p < 0.01) while drilling at 800 rpm (8.90 °C ± 0.50) produced significantly less heating of the root surface (p < 0.05) than drilling at 1000 rpm (10.09 °C ± 1.32). Cooling significantly decreased (p < 0.01) temperature elevations at a drill speed of 1000 rpm, and cooling liquid temperatures of 4-6 °C proved significantly (p < 0.01) more beneficial in decreasing temperature elevations (1.60 °C ± 1.17) than when compared with room temperature (21 °C) liquids (4.01 °C ± 0.22)., Conclusions: Based on the results of our study, guided endodontic drilling at drill speeds not exceeding 1000 rpm following access cavity preparation, with constant cooling using a fluid cooler than room temperature, provides the best results in avoiding collateral thermal damage during navigated endodontic drilling of root canals., (© 2024. The Author(s).)

Background: The purpose of this in vitro study was to compare the accuracy of implant placement in model surgeries according to the design of the drills (straight drills or step drills) used to finalize the implant bed during pilot-guided static computer-assisted implant surgery (sCAIS)., Methods: Model surgeries were carried out on resin models randomly assigned to three study groups. Virtual planning software (coDiagnostiX 10.6, Dental Wings, Montreal, Canada) was used to plan the implant positions. In Groups 1 and 2, pilot-guided sCAIS was performed. Straight drills were used in Group 1, and step drills were used in Group 2 to finalize the implant beds. In Group 3, fully guided sCAIS was performed using a universal fully guided kit (RealGUIDE Full Surgical Kit 3DIEMME, RealGUIDE, Cantù, Como, Italy). A total of 90 dental implants (Callus Pro, Callus Implant Solutions GmbH, Nuremberg, Germany) were placed (six implants per model, five models per study group). The primary outcome variables (angular deviation, coronal global deviation, and apical global deviation) were calculated for all implants based on the comparison of the preoperative surgical plan with the postoperative scans., Results: Group 2 (coronal global deviation, 0.78 ± 0.29 mm; apical global deviation, 1.02 ± 0.56 mm) showed significantly lower values of both global deviation variables than Group 1 (coronal global deviation, 0.95 ± 0.20 mm; apical global deviation, 1.42 ± 0.49 mm). However, there was no significant difference in angular deviation between Groups 1 and 2 (7.56 ± 2.92° and 6.44 ± 2.84°). Group 3 produced significantly lower values of all three primary outcome variables (angular deviation, 2.36 ± 0.90°; coronal global deviation, 0.59 ± 0.28 mm; apical global deviation, 0.90 ± 0.29 mm) than Group 1 and significantly lower angular deviation and coronal global deviation values than Group 2., Conclusions: The design of the drills used to finalize implant osteotomies during pilot-guided sCAIS influences dental implant placement accuracy. Using step drills instead of straight drills for final osteotomies decreases deviation from the surgical plan. The fully guided approach performed better than the pilot-guided sCAIS., (© 2023. BioMed Central Ltd., part of Springer Nature.)

The study evaluated the interaction of a titanium dental implant surface with three different antibacterial solutions: chlorhexidine, povidone-iodine, and chlorine dioxide. Implant surface decontamination is greatly challenging modern implant dentistry. Alongside mechanical cleaning, different antibacterial agents are widely used, though these could alter implant surface properties. Commercially pure (CP) grade 4 titanium (Ti) discs were treated with three different chemical agents (chlorhexidine 0.2% (CHX), povidone-iodine 10% (PVPI), chlorine dioxide 0.12% (ClO 2 )) for 5 min. Contact angle measurements, X-ray photoelectron spectroscopy (XPS) analysis, and cell culture studies were performed. Attachment and proliferation of primary human osteoblast cells were investigated via MTT (dimethylthiazol-diphenyl tetrazolium bromide), alamarBlue, LDH (lactate dehydrogenase), and fluorescent assays. Contact angle measurements showed that PVPI-treated samples (Θ = 24.9 ± 4.1) gave no difference compared with controls (Θ = 24.6 ± 5.4), while CHX (Θ = 47.2 ± 4.1) and ClO 2 (Θ = 39.2 ± 9.8) treatments presented significantly higher Θ values. All samples remained in the hydrophilic region. XPS analysis revealed typical surface elements of CP grade 4 titanium (Ti, O, and C). Both MTT and alamarBlue cell viability assays showed similarity between treated and untreated control groups. The LDH test revealed no significant difference, and fluorescent staining confirmed these results. Although there was a difference in surface wettability, a high proliferation rate was observed in all treated groups. The in vitro study proved that CHX, PVPI, and ClO 2 are proper candidates as dental implant decontamination agents., Competing Interests: The authors declare no conflicts of interest.

Class II malocclusion is one of the most common dental anomalies and the use of intermaxillary elastomers is the standard method in its treatment. However, orthodontic elastics cannot exert continuous force over a period of time due to force degradation. Our goal was to mechanically characterize the different types of elastomers during static and cyclic loads, based on uniform methodology and examine the morphological changes after loading. Ten types of latex-containing and four latex-free intermaxillary elastics were examined from six different manufacturers. To determine the mechanical characteristics of the elastomers, tensile tests, cyclical tensile fatigue tests and 24 h relaxation tests were performed, and the elastics were also subjected to scanning electron microscopy (SEM) and Raman spectroscopy. Regardless of the manufacturer, the latex-containing elastomers did not show significant differences in the percentage of elongation at break during the tensile test. Only one type of latex-containing elastomer did not tear during the 24 h cyclical fatigue test. Fatigue was confirmed by electron microscopy images, and the pulling force reduced significantly. During the force relaxation test, only one latex-free ligature was torn; the force degradation was between 7.8% and 20.3% for latex ligatures and between 29.6% and 40.1% for latex-free elastomers. The results showed that dynamic loading was more damaging to ligatures than static loading, latex-containing elastomers were more resistant than latex-free elastics, and which observation could have clinical consequences or a potential effect on patient outcome.

Objectives: The influence of energy drinks on dental materials are relatively under addressed. Our aim was to investigate the effect of energy drinks on dental materials used intraorally in young individuals. Commonly used preventive, restorative, and orthodontic materials were tested in vitro ., Methods: The effect of two commercially available energy drinks (HELL, BURN) was investigated on different dental materials: machined, anodized Titanium (grade 5: Ti6Al4V) and composites (Grandio Seal, VOCO; Filtek Z250, 3M ESPE; Estelite SQ, TOKUYAMA). The roughness (Ra) and morphological changes were examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM)., Results: AFM and SEM revealed significant differences in the Ra and morphology of the samples. AFM results for the machined and anodized titanium samples showed that the two energy drinks modified the surface roughness differently; BURN changed the roughness of machined samples significantly, while anodized discs were not altered significantly by the two energy drinks. In case of composite samples there was no significant difference for the Estelite SQ, relative low differences for the Filtek Z250 and significant changes in the morphology and surface roughness of Grandio Seal., Significance: On all tested materials, changes in the surface roughness and morphology were more or less detected, proving energy drinks do in fact have a harmful effect. It can be concluded that material erosion depends on the material composition and particle arrangement. Where the surface is characterized by a regular, uniform particle arrangement, energy drinks are less able to influence the roughness, while for samples where the surface is rich in aggregates, the material erodes the surface much more easily., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors. Published by Elsevier Ltd.)

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 (R a ) 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., Competing Interests: The authors declare no conflict of interest., (© 2022 The Author(s).)

Objective: Bacterial adhesion and colonization on implanted devices are major etiological factors of peri-implantitis in dentistry. Enhancing the antibacterial properties of implant surfaces is a promising way to reduce the occurrence of inflammations. In this in vitro study, the antibacterial potential of two nanocomposite surfaces were investigated, as possible new materials for implantology., Material and Methods: The structural and photocatalytic properties of the TiO 2 and Ag-TiO 2 (with 0.001 wt% plasmonic Ag content) photocatalyst containing polymer based composite layers were also studied and compared to the unmodified standard sandblasted and acid etched Ti discs (control). The presence of visible light induced reactive oxygen species was also verified and quantified by luminol based chemiluminescence (CL) probe method. The discs with adhered Streptococcus mitis were illuminated for 5, 10 and 15 min. The antibacterial effect was determined by the metabolic activities of the adhered and proliferated bacterial cells and protein assay at each time point., Results: The Ag-TiO 2 containing surfaces with obvious photocatalytic activity eliminated the highest amount of the metabolically active bacteria, compared to the control discs in the dark, after 15 min illumination., Conclusions: The plasmonic Ag-enhanced and illuminated surface exhibits significantly better antibacterial activity under harmless visible light irradiation, than the control Ti or TiO 2 containing copolymer. The studied surface modifications could be promising for further, more complex investigations associated with dental research on infection prevention in connection with oral implantation., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The biofilm formation by oral bacteria on the implant surface is one of the most remarkable factors of peri-implant infections, which may eventually lead to bone resorption and loss of the dental implant. Therefore, the elimination of biofilm is an essential step for the successful therapy of implant-related infections. In this work we created a basic in vitro model to evaluate the antibacterial effect of three widely used antiseptics.Commercially pure (CP4) titanium sample discs with sand blasted, acid etched, and polished surface were used. The discs were incubated with mono-cultures of Streptococcus mitis and Streptococcus salivarius. The adhered bacterial biofilms were treated with different antiseptics: chlorhexidine-digluconate (CHX), povidone-iodine (PI), and chlorine dioxide (CD) for 5 min and the control discs with ultrapure water. The antibacterial effect of the antiseptics was tested by colorimetric assay.According to the results, the PI and the CD were statistically the most effective in the elimination of the two test bacteria on both titanium surfaces after 5 min treatment time. The CD showed significant effect only against S. salivarius.Based on our results we conclude that PI and CD may be promising antibacterial agents to disinfecting the peri-implant site in the dental practice.

Failure of dental implants is caused mainly by peri-implant infections resulting in loss of supporting bone. Since there is no ideal therapy of peri-implantitis, the focus of research has been shifted toward better prevention and the development of antibacterial surfaces. In our study we examined the attachment and proliferation of primary epithelial and MG-63 osteosarcoma cells on Ti dental implants coated with photocatalytic nanohybrid films. Two polyacrylate resin based layers were investigated on commercially pure (CP4) Ti discs: 60 wt% TiO2/40 wt% copolymer and 60 wt% Ag-TiO2/40 wt% copolymer ([Ag] = 0,001 wt%). Surface properties were examined by scanning electron microscopy (SEM) and profilometry. Cell responses were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT) and visualized with fluorescence microscopy. Profilometry revealed significant changes in surface roughness of TiO2 (Ra = 1.79 μm) and Ag-TiO2 layers (Ra = 5.76 μm) compared to the polished (Ra(P) = 0.13 μm) and sandblasted, acid-etched control surfaces (Ra(SA) = 1.26 μm). MTT results demonstrated that the attachment (24 h) of epithelial cells was significantly higher on the Ag-TiO2 coated samples (OD540 = 0.079) than on the polished control surfaces (OD540 = 0.046), whereas MG-63 cells did not show any difference in attachment between the groups. After one week, epithelial cells showed slightly increased survival as compared to MG-63 cells. The results suggest that the tested coatings are cytocompatible with epithelial cells, which means that they are not only antibacterial, but they also appear to be promising candidates for implantological use.

Antibacterial surfaces have been in the focus of research for years, driven by an unmet clinical need to manage an increasing incidence of implant-associated infections. The use of silver has become a topic of interest because of its proven broad-spectrum antibacterial activity and track record as a coating agent of soft tissue implants and catheters. However, for the time being, the translation of these technological achievements for the improvement of the antibacterial property of hard tissue titanium (Ti) implants remains unsolved. In our study, we focused on the investigation of the photocatalysis mediated antibacterial activity of silver (Ag), and Ti nanoparticles instead of their pharmacological effects. We found that the photosensitisation of commercially pure titanium discs by coating them with an acrylate-based copolymer that embeds coupled Ag/Ti nanoparticles can initiate the photocatalytic decomposition of adsorbed S. salivarius after the irradiation with an ordinary visible light source. The clinical isolate of S. salivarius was characterised with MALDI-TOF mass spectrometer, while the multiplication of the bacteria on the surface of the discs was followed-up by MTT assay. Concerning practical relevance, the infected implant surfaces can be made accessible and irradiated by dental curing units with LED and plasma arc light sources, our research suggests that photocatalytic copolymer coating films may offer a promising solution for the improvement of the antibacterial properties of dental implants., (© The Author(s) 2016.)

Objectives: Acidic pH and high fluoride (F(-)) concentration impair the corrosion resistance of titanium (Ti). Caries-preventive products contain high amounts of F(-) and are applied at low pH. The purpose of this study was to evaluate whether fluoride applied in different forms has different short-, mid-, and long-term effects on the growth of the bacteria Streptococcus mutans., Materials and Methods: Ti discs with polished surface were treated with a rinse containing 0.025% olaflur, a gel containing 1.25% olaflur, or a 1% aqueous solution of NaF (pH 4.5), and they were incubated with S mutans for 21 days. Control discs did not get prophylactic treatment. Protein assay analysis was performed at regular intervals to estimate the amount of S mutans. Scanning electron microscopic (SEM) images were also taken., Results: Bacterial protein quantity became significantly different only by the 21st day. Fluoride in rinse and gel proved to be superior to NaF in aqueous solution or no treatment (P < 0.01 and P < 0.05, respectively). However, the discs treated with fluoride in gel showed signs of corrosion in SEM images., Conclusion: The results suggest that the use of fluoride-containing mouthwashes might be the best and safest oral hygienic choice for patients with oral implants. Furthermore, olaflur seems to be superior to NaF for long-term use at low pH.

The instrumental measurement of volatile sulphur compounds is a common practice to assess halitosis. One of the most widespread devices for that purpose is OralChroma(TM), a combination of a semiconductor gas sensor and a compact gas chromatograph (GC) system. Several lines of evidence indicate that although the hardware of OralChroma(TM) is fit for the precise measurement of volatile sulphur compounds (VSCs), its software needs revision to allow that precision. In this study we sought to develop software to solve this problem, and to test the utility of the new software in a population of patients and controls. The results were also compared with VSC measurements performed with Halimeter(®), another widespread device, so as to assess the correlation. A set of measurements involving volunteers (21 controls and 14 oral cancer patients) were conducted. The analysis of the chromatograms recorded by OralChroma(TM) indicated that the majority of the studied breath samples contained significant amounts of isoprene (the peak was around 100 s) and acetaldehyde (the peak was around 350 s), therefore OralChroma(TM) was also calibrated for both isoprene and acetaldehyde. A linear relationship was found between the concentration (in the range of 80-1400 ppbv for acetaldehyde and 40-560 ppbv for isoprene) and the area under the corresponding peak. In numerous cases the concentrations of VSCs calculated by the software of OralChroma(TM) required revision. In the new software, the concentrations of the VSCs, isoprene and acetaldehyde were determined by fitting the chromatograms with the sum of six Gaussian functions. Based on the findings of the present study we conclude that our new software allows an improved and instantaneous evaluation of OralChroma(TM) chromatograms with the additional possibility of determining the isoprene and acetaldehyde concentrations from breath samples.

Objectives: Health condition of the gingival tissues contacting the surfaces of fixed prostheses is a result of multiple etiologic factors. The aim of the investigation discussed here was to evaluate the attachment and proliferation rate of cultured human epithelial cells on three commonly used restorative materials under in vitro conditions., Methods: Morphological and chemical structure of polished lithium-disilicate (IPS e.max Press, Ivoclar Vivadent AG, Germany), yttrium modified zirconium dioxide (5-TEC ICE Zirkon Translucent, Zirkonzahn GmbH Srl, Germany) and cobalt chromium alloy (Remanium star, Dentaurum GmbH & Co. KG, Germany) discs were examined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM). Human epithelial cells harvested and cultured from one donor, were applied to investigate cell attachment (24h observation) and proliferation (72h observation) via dimethylthiazol-diphenyl tetrazolium bromide (MTT) and AlamarBlue(®) (AB) assays on control surface (cell-culture plate) and on the restorative materials (n=3×20 specimens/material)., Results: SEM and AFM revealed typical morphology and roughness features for the materials. Zirconia presented significantly higher Ra value. EDS confirmed typical elements on the investigated restorative materials: lithium-disilicate (Si, O); Zirconia (Zi, Y, O); CoCr (Co, Cr, W). All surfaces except CoCr exhibited significant cell proliferation according to MTT and AB assays after 72h compared to 24h. Among the restorative materials, CoCr samples showed the highest cell attachment as indicated by MTT assay. AB results showed that attachment and proliferation of human epithelial cells is supported more on lithium-disilicate. Both assays indicated the lowest value for zirconia., Conclusions: The results indicate that the restorative materials examined are equally suitable for subgingival restorations. Lithium-disilicate exhibited the best biocompatibility., Clinical Significance: The examined materials are indicated for use in restorative procedures, directly contacting the sulcular epithelial tissues. Thus it is essential to monitor the biological acceptibility of these materials in order to better understand their clinical properties. The results indicate that Lithium-disilicate is a suitable material for such purposes., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

ABO blood group antigen (ABGA) secretion into the saliva and other body fluids is a well-known phenomenon, and there is evidence to suggest a link between secretor status and the appearance of caries. It has been proposed that secretion of these antigens into the saliva might be caries-preventive, however, this proposition is still a matter of debate. Our aim was to examine the relationship between caries experience and secretor status in a group of Hungarian children and adolescents in a cross-sectional study. Altogether 130 children and adolescents participated in the study (aged 6-18 years). Participants were divided into two groups according to dentition (i.e. mixed and permanent). ABGA were determined from saliva. The DMF-T and dmf-t (decayed, missing, and filled) indices were calculated, as well as the oral health hygiene index-simplified plaque index. Association of these indices with secretor status was examined. In mixed dentition, the mean dmf-t values were significantly lower in the secretor group (2.1 ± 0.52 SEM), as compared to the nonsecretor group (3.8 ± 0.93 SEM; p < 0.05, Mann-Whitney U test). The finding that children of mixed dentition are apparently better protected against caries suggests that the assumed protective effect might be associated with deciduous teeth, but given the general paucity of knowledge about this topic, further research is indicated.

Demand is increasing for shortening the long (3-6 months) osseointegration period to rehabilitate patients' damaged chewing apparatus in as short a time as possible. For dental implants, as for biomaterials in general, the bio- and osseointegration processes can be controlled at molecular and cellular levels by modification of the implant surface. One of the most promising of such surface modifications is laser ablation, as demonstrated by our previous results [46]. Commercially pure (CP4) sand-blasted, acid-etched titanium disks (Denti® System Ltd., Hungary) were irradiated with a KrF excimer laser (248 nm, fluence 0.4 J/cm(2), FWHM 18 ns, 2000 pulses), or with a Nd:YAG laser (532 nm, 1.3 J/cm(2), 10 ns, 200 pulses) then examined by SEM, AFM, and XPS. In vitro attachment (24 h) and proliferation (72 h) of MG-63 osteoblast cells were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT), alamarBlue (AB) assays alkaline phosphatase quantification (ALP) and SEM. SEM and AFM revealed significant changes in morphology and roughness. XPS confirmed the presence of TiO2 on each sample; after Nd:YAG treatment a reduced state of Ti (Ti(3+)) was also observed. MTT, AB and ALP measurements detected an increase in the number of cells between the 24- and 72 hour observations; however, laser treatment did not affect cell attachment and proliferation significantly., (© 2013.)

Fluorides may affect the oxide layer on titanium surface. Caries preventive mouthwashes or gels contain fluorides and are applied at low pH. The aim of the present work was to study whether various concentrations of fluoride at acidic pH cause changes in the surface structure on the polished region of Ti implants, and alter the adherence and colonization of bacteria. Commercially pure Ti grade 4 discs with a polished surface were treated with a mouthwash containing 0.025% fluoride, a gel containing 1.25% fluoride or a 1% aqueous solution of NaF (pH 4.5). The change of surface roughness of the samples and the colonization of Porphyromonas gingivalis strains were studied by scanning electron microscopy after 5 days of anaerobic incubation. The quantity of the bacterial protein was determined by protein assay analysis. Agents with high fluoride concentration at acidic pH increased the roughness of the Ti surface. A slight increase in the amount of bacteria was found on the surfaces treated with 1% NaF and gel in comparison with the control surface. This study suggested that a high fluoride concentration at acidic pH may hinder the development of a healthy transgingival epithelial junction on Ti implants, due to bacterial colonization.

Introduction: The effects of three different decontaminating solutions in clinical use for peri-implantitis therapy on the chemical structure and surface roughness of commercially pure (CP) Ti were investigated. A further aim was to survey the response of the biological environment to these changes, by examining the attachment and proliferation of human epithelial cells after treatment of the Ti surfaces with these solutions., Materials and Methods: CP (grade 4) machined titanium discs (CAMLOG Biotechnologies AG, Switzerland) were treated with 3% H2O2 (5 min), saturated citric acid (pH = 1; 1 min) or chlorhexidine gel (CHX, 5 min). The surface properties were followed through the use of X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The epithelial cell attachment and proliferation was examined by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and bicinchoninic acid (BCA) protein-content assays., Results: XPS showed an intact TiO2 layer on each sample and CHX was adsorbed by the surface, as C-O and/or C=O bond formation was revealed. AFM results gave no significant changes in the roughness after treating the surfaces with the cleaning solutions. While MTT and BCA assays did not show significant differences in epithelial cell attachments, the cell proliferation was significantly increased after H2O2 treatment as compared to CHX (not shown by BCA assays)., Conclusions: The applied decontaminating agents do not damage the Ti surface. H2O2 can be used effectively in decontaminating the implants affected by peri-implantitis, as the human epithelial cell growth was improved, in contrast with CHX.

The treatment of peri-implantitis, which causes tissue deterioration surrounding osseointegrated implants, involves surface decontamination and cleaning. However, chemical cleaning agents may alter the structure of implant surfaces. We investigated three such cleaning solutions. Commercially pure (grade 4) machined titanium discs (CAMLOG Biotechnologies AG, Switzerland) were treated with 3% H(2)O(2) (5 min), saturated citric acid (pH = 1) (1 min) or chlorhexidine gel (5 min), and their surface properties were examined by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Human epithelial cell attachment (24-h observation) and proliferation (72-h observation) were investigated via dimethylthiazolyl-diphenyltetrazolium bromide (MTT) and bicinchoninic acid (BCA) protein content assays. AFM revealed no significant difference in roughness of the three treated surfaces. XPS confirmed the constant presence of typical surface elements and an intact TiO(2) layer on each surface. The XPS peaks after chlorhexidine gel treatment demonstrated C-O and/or C=O bond formation, due to chlorhexidine digluconate infiltrating the surface. MTT and BCA assays indicated similar epithelial cell attachments in the three groups; epithelial cell proliferation being significantly higher after H(2)O(2) than after chlorhexidine gel treatment (not shown by BCA assays). These agents do not harm the Ti surface. Cleaning with H(2)O(2) slightly enhances human epithelial cell growth, in contrast to chlorhexidine gel., ((c) 2010 Wiley Periodicals, Inc.)

Fluoride is a reductive agent and may modify the oxide layer of titanium (Ti) in the transgingival region of dental implants. The low pH and the high fluoride concentration of prophylactic mouthwashes and gels (used in caries prevention) may play a role in this phenomenon. Our main goal was to examine whether changes on the surface structure of Ti caused by high fluoride concentration and acidic pH alter the adherence and the colonization of bacteria. Polished commercially pure Ti discs (CP grade 4, Camlog, Biotechnologies AG, Switzerland) were used in the study. Each sample was treated for 1 hour with one of the solutions: mouthwash containing 0.025% (250 ppm) fluoride, a gel containing 1.25% (12500 ppm) fluoride, and a solution of 1% NaF (3800 ppm fluoride), pH 4.5. The surface structure of the discs was analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The colonization of Streptococcus mutans was studied by scanning electron microscope (SEM) after a 5-day incubation period. The roughness of the treated sample surfaces (Ra), as revealed by AFM measurements, increased 1.3 times for the gel and the mouthwash, and approximately seven folds for the 1% NaF solution, as compared to the control surface. The high fluoride concentration and acidic pH of the gel and the 1% NaF solution resulted in a strong corrosion and a modification of the composition of the Ti surface. The XPS spectra showed the formation of a fluoride containing complex (Na2TiF6) bound strongly to the surface. A correlation was revealed between the roughness of the surface and thickness and maturity of the S. mutans bacterial colonies developed on the modified Ti surface. High fluoride concentration and acidic pH increased the roughness of the Ti surface. Bacterial biofilm colonization on this rough surface proved to be more mature. The amount of bacteria was increased due to the changes in the surface caused by fluoride treatment. The present study indicates that high fluoride concentration in an acidic pH environment may affect the development of a healthy transgingival epithelial junction on the Ti surface. This work was supported by the SIMI-NAS Project of the 5th FWP of the European Commission (Growth Program, GRD3-2001-61801), the Hungarian Ministry of Economy and the EC (GVOP-3.2.1.-2004-04-0408/3.0), the Hungarian Ministry of Health (ETT, 434/2006), and the Hungarian Scientific Research Fund (OTKA F-68440).

High fluoride (F(-)) concentrations and acidic pH impair the corrosion resistance of titanium (Ti). Effects of F(-)-containing caries-preventive prophylactic rinses, and gels on Ti were investigated by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Human epithelial cell attachment and proliferation were investigated by dimethylthiazol-diphenyl tetrazolium bromide (MTT) and protein content assays. Aqueous 1% NaF solution (3800 ppm F(-), pH 4.5) or high (12,500 ppm) F(-) content gel (pH 4.8) strongly corroded the surface and modified its composition. XPS revealed formation of a strongly bound F(-)-containing complex (Na(2)TiF(6)). AFM indicated an increase in roughness (R(a)) of the surfaces: 10-fold for the NaF solution and smaller for the gel or a mouthwash (250 ppm F(-), pH 4.4). MTT revealed that cell attachment was significantly increased by the gel, but was not disturbed by either the mouthwash or the NaF. Cell proliferation determined by MTT decreased significantly only for the NaF-treated samples; protein content assay experiments showed no such effect. This study indicates that epithelial cell culturing results can depend on the method used, and the adverse effects of a high F(-) concentration and low pH should be considered when prophylactic gels are applied by patients with Ti implants or other dental devices.

The aim of this pilot investigation was to develop a new animal model for studying the effects on osteogenesis of agents used in the guided bone regeneration technique. As test material, a mixture of two osseoconductive materials with different physico-chemical characteristics was used. One component of the mixture was Bio-Oss, a bovine hydroxyapatite; the other was Cerasorb, a synthetic tricalcium phosphate. The mixture consisited of 50 volume percent of Bio-Oss and 50 volume percent of Cerasorb. In in vivo pilot experiment, bone wounds were prepared in the proximal third of both femurs of rabbits. A Cerasorb + Bio-Oss mixture was inserted on the test side and the same amount of sterile buffered physiological solution on the control side. After healing for 4 weeks, the bone segments were embedded and cut without decalcification, using the Exact cutting and grinding system. The density of the newly-formed bone was evaluated histomorphometrically. On the Cerasorb + Bio-Oss test side the bone density was almost 1.5 times higher than that on the control side. These results demonstrated that the applied animal model is appropriate for investigation of the effects on osteogenesis of biocompatible graft materials such as Bio-Oss and Cerasorb.

The high fluoride concentration and the acidic pH in tooth-paste used to prevent caries may modify the surface structure of implants made of titanium. Oxidative agents thicken and condense the titanium-dioxid layer on the surface of titanium and improve its stability against corrosion effects, while reductive agents like fluoride may have the opposite effect and attack this layer. The aim of the present work was to study the effects of fluoride containing toothpaste and gel on the titanium dioxid layer of titanium. The surfaces of the titanium (commercial pure grade I.) discs were treated with toothpaste and gel containing 0.125 % and 1.25 % fluoride, respectively. The changes in the surface structure were analyzed by atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). Our results demonstrated that fluoride strongly binds to the titanium surface and modifies its structure in case of fluoride containing gels.

Chemically modified biomaterial surfaces (titanium and glass) covered with polyelectrolyte self-assembled films formed by the alternating adsorption of cationic poly-L-lysine (PLL) and anionic poly-L-glutamic acid (PGA) were structurally characterized by atomic force microscopy. Complementary information concerning the thickness and layer-by-layer growth of the films was provided by optical waveguide light-mode spectroscopy. The frequently used ex situ and the rarely used in situ build-up methods were compared. Important aspects of the industrial applicability of these films, their stability in time, and possible differences in their morphology were investigated. The films revealed a granular pattern, with grain diameters of 270 +/- 87 nm for glass (up to 8 bilayers) and 303 +/- 89 nm for titanium (up to 10 bilayers), independently of the build-up procedure. Both surfaces displayed a rehydration capability, the titanium surface exhibiting a better stability in time. The high roughness values observed at acidic or basic pH are related to the degree of ionization of PGA and PLL.

Isotopic effects in the fragmentation of excited target residues following collisions of 12C on (112,124)Sn at incident energies of 300 and 600 MeV per nucleon were studied with the INDRA 4pi detector. The measured yield ratios for light particles and fragments with atomic number Z < or = 5 obey the exponential law of isotopic scaling. The deduced scaling parameters decrease strongly with increasing centrality to values smaller than 50% of those obtained for the peripheral event groups. Symmetry-term coefficients, deduced from these data within the statistical description of isotopic scaling, are near gamma = 25 MeV for peripheral and gamma < 15 MeV for central collisions.

The biointegration of dental and orthopaedic implants depends mainly on the morphology and physical-chemical properties of their surfaces. Accordingly, the development of the desired microstructure is a relevant requirement in the bulk manufacture. Besides the widely used sandblasting plus acid etching and plasma-spray coating techniques, the laser surface modification method offers a plausible alternative. In order to analyze the influence of the laser treatment, the surfaces of titanium samples were exposed to excimer laser irradiation. The aim of this study was to develop surfaces that provide optimal conditions for bone-implant contact, bone growth, formation and maintenance of gingival attachment. For this purpose, holes were ablated on the surface of samples by nanosecond (18 ns, ArF) and also sub-picosecond (0,5 ps, KrF) laser pulses. Using pulses of ns length, due to melt ejection, crown-like protrusions were formed at the border of the holes, which made them sensitive to mechanical effects. To avoid these undesirable crown-like structures ultrashort KrF excimer laser pulses were successfully applied. On the other hand, titanium samples were laser-polished in favour of formation and connection of healthy soft tissues. Irradiation by a series of nanosecond laser pulses resulted in an effective smoothening as detected by atomic force microscopy (AFM). By inhibiting plaque accumulation this favours formation of gingival attachment. X-ray photoelectron spectroscopy (XPS) studies showed that laser treatment, in addition to micro-structural and morphological modification, results in decreasing of surface contamination and thickening of the oxide layer. X-ray diffraction (XRD) analysis revealed that the original alpha-titanium crystalline structure of the laser-polished titanium surface was not altered by the irradiation.

Medical implants used in oral and orthopaedic surgery are mainly produced from titanium. Their biological behaviour, e.g. osseointegration, essentially depends on both the chemical composition and the morphology of the surface. Modifications achieved by excimer laser irradiation of titanium samples were investigated in order to improve their surface characteristics so as to facilitate biointegration. To enlarge the effective interfacial area of bone-implant contact, holes were ablated by laser pulses of ns or sub-ps length. During ns ablation, crown-like projecting rims formed around the borders of the holes. Ultra-short (0.5ps) KrF excimer laser pulses were successfully applied to avoid these undesirable formations. Since a smooth dental implant surface is necessary to maintain a healthy connection with the soft tissues, laser polishing of samples was investigated, too. Irradiation with a series of ns laser pulses resulted in effective smoothing, as measured with atomic force microscope. X-ray photoelectron spectroscopy analysis of the laser-polished titanium surface revealed that laser treatment led to a decrease of the surface contamination and in thickening of the oxide layer. X-ray diffraction measurements demonstrated that the original alpha-titanium crystal structure was preserved.

Production of octacalcium phosphate crystals on the surface of titanium dioxide particles was achieved at high concentration of titania particles. Optimising the speed of addition of the reagents in the process of crystal growth in heterogeneous nucleation reaction led to reproducible OCP crystal structure on the particle surface. The crystal structure of OCP was investigated by SEM, XRD and FTIR methods. The same crystallization process on the surface of metallic titanium plates did not result in formation of OCP crystals. The evaporated titanium layers on a glass surface and titanium plates without excimer laser treatment did not bond calcium phosphate at any rate. SEM investigations imply that the surface layer of titanium plates changes radically due to laser beam treatment, likely because of oxidation of titanium in the process of evaporation followed by deposition back onto the surface. The calcium phosphate formation on these oxidised titanium plates could be observed by SEM. It can be concluded, that for OCP-formation on titanium metal surface it is necessary to form a thick oxide layer, as the native oxide layer in the case of non-treated titanium substrates did not bound the calcium phosphate, while formation of calcium phosphate could be reached on the laser-treated surface.

Millisecond delayed fluorescence from the isolated reaction center of photosynthetic bacteria Rhodobacter sphaeroides was measured after single saturating flash excitation and was explained by thermal repopulation of the excited bacteriochlorophyll dimer from lower lying charge separated states. Three exponential components (fastest, fast, and slow) were found with lifetimes of 1.5, 102, and 865 ms and quantum yields of 6.4 x 10(-9), 2.2 x 10(-9), and 2.6 x 10(-9) (pH 8.0), respectively. While the two latter phases could be related to transient absorption changes, the fastest one could not. The fastest component, dominating when the primary quinone was prereduced, might be due to a small fraction of long-lived triplet states of the radical pair and/or the dimer. The fast phase observed in the absence of the secondary quinone, was sensitive to pH, temperature, and the chemical nature of the primary quinone. The standard free energy of the primary stable charge pair relative to that of the excited dimer was -910 +/- 20 meV at pH 8 and with native ubiquinone, and it showed characteristic changes upon pH and quinone replacement. The interaction energy ( approximately 50 meV) between the cluster of the protonatable groups around GluL212 and the primary semiquinone provides evidence for functional linkage between the two quinone binding pockets. An empirical relationship was found between the in situ free energy of the primary quinone and the rate of charge recombination, with practical importance in the estimation of the free energy levels from the easily available lifetime of the charge recombination. The ratio of the slow and fast components could be used to determine the pH dependence of the free energy level of the secondary stable charge pair relative to that of the excited dimer.