Bioactive glasses in air particle abrasion treatment of contaminated implant surfaces

The use of dental implants has become an established treatment modality with a predictable survival rate. However, inflammation of peri-implant tissue, peri-implant mucositis, may occur over time due to the establishment of bacterial biofilm on the implant surfaces. If left untreated, the inflammation can extend apically, resulting in a condition called peri-implantitis (PI), which is characterized by submucosal infection and peri-implant bone resorption. Therefore, one of the main objectives of PI therapy is the removal of bacterial biofilm from the implant surface. This study series aimed to evaluate the effect of bioactive glass (BAG) powder in air particle abrasion treatment of titanium alloy surfaces. A further aim was to study the antibacterial properties of BAG abraded surfaces and to examine the effect of BAG air-abrasion on bacterial biofilm removal on sandblasted and acidetched (SA) titanium alloy surfaces. An additional aim was to study the attachment, viability, and proliferation of human osteoblast-like MC3T3-E1 cells on SA surfaces subjected to BAG air particle abrasion. The effect of BAG air-abrasion on the antibacterial properties of smooth titanium disc surfaces was evaluated for 45S5 BAG and three novel zinc oxide doped BAGs: Zn4, Zn6, and Zn4Sr8. SA titanium discs were used to assess the BAG air-abrasion effect on surface chemistry, roughness, wettability, and surface free energy. Streptococcus mutans, as well as Fusobacterium nucleatum and Porphyromonas gingivalis dual biofilms, were formed on SA titanium discs. SA discs with biofilms were subjected to BAG air-abrasion and then cultured in an anaerobic chamber for 5 hours for S. mutans and 21 hours for F. nucleatum and P. gingivalis dual biofilms. The efficiency of biofilm removal was evaluated using scanning electron microscopy (SEM) imaging and culturing techniques. The thrombogenicity of the BAG air-abraded discs was assessed spectrophotometrically using whole blood clotting measurement at predetermined time points. The viability and proliferation of pre-osteoblastic MC3T3-E1 cells were evaluated on SA surfaces with and without BAG air-abrasion. The air-abrasion procedures were similar for all experiments. Each titanium alloy disc was air-abraded for 20 seconds, at a 90 angle, 3 mm distance, and 4 bars air pressure. A statistically significant decrease in the viability and biofilm formation of S. mutans was observed for BAG air-abraded titanium discs. Air particle abrasion with BAG effectively eradicated S. mutans and F. nucleatum and P. gingivalis dual biofilms formed on SA surfaces compared with inert glass air-abrasion. No significant difference was seen in the speed of blood clot formation since complete blood clotting was achieved in 40 minutes on all substrates. Air-abrasion of SA titanium discs with BAG or inert glass significantly reduced surface roughness, enhanced the wettability and surface free energy of the SA surfaces. MC3T3-E1 cell number was higher for SA surfaces air-abraded with Zn4 BAG or 45S5 BAG than inert glass. Confocal laser scanning microscope images showed that the pre-osteoblast cells did not spread as well on the SA and BAG abraded surfaces as they did on control cover glass discs. However, for 45S5 and Zn4 BAG abraded substrates, cells spread the most within 24 hours and changed their morphology to more spindle-like when cultured further. It can be concluded that air particle abrasion with BAG has good potential for the treatment of periimplantitis. However, their effectiveness needs to be evaluated in vivo before any definitive conclusion can be made.Bioaktiiviset lasit kontaminoituneiden implanttipintojen ilmaabraasio käsittelyssä Hammasimplanttien käytöstä on tullut vakiintunut ja hyväennusteinen hoitomuoto. Hammasimplantteja ympäröivien pehmytkudosten tulehdus, peri-implantti mukosiitti, voi kuitenkin ilmetä implanttien ympärillä bakteereiden muodostaman biofilmin aiheuttamana. Hoitamattomana infektio voi levitä syvemmälle pehmytkudoksiin johtaen peri-implantiitiksi kutsuttuun tilaan, jota karakterisoi ikenen alainen tulehdusreaktio ja implanttia ympäröivän luun resorboituminen. Peri-implantiittihoidon tärkein tavoite on bakteerien muodostaman biofilmin eliminoiminen implantin pinnalta. Tämän tutkimussarjan tavoitteena oli selvittää bioaktiivisella lasijauheella tehdyn ilma-abraasiokäsittelyn vaikutus titaaniyhdisteen pintaan. Tarkoituksena oli myös tutkia bioaktiivisella lasilla hiekkapuhallettujen pintojen antimikrobisia ominaisuuksia sekä selvittää bioaktiivisella lasilla tehdyn hiekkapuhalluksen vaikutus biofilmien poistoon hiekkapuhalletuilta ja happoetsatuilta (SA; sand blasted acid etched) titaanipinnoilta. Tämän lisäksi tarkoituksena oli tutkia ihmisen osteoblastin kaltaisten MC3T3-E1 solujen tarttuminen, elinkyky ja jakautuminen SA -pintaisilla titaaninäytteillä bioaktiivisella lasilla tehdyn hiekkapuhalluskäsittelyn jälkeen. Bioaktiivisella lasilla tehdyn hiekkapuhalluksen vaikutuksia tasaisen titaanikiekon pinnan antimikrobisiin ominaisuuksiin selvitettiin 45S5 bioaktiivisella lasilla ja kolmella uudella sinkkipitoisella lasilla: Zn4, Zn6, ja Zn4Sr8. SA -pintaisia titaanikiekkoja käytettiin tutkittaessa bioaktiivisella lasilla tehdyn hiekkapuhalluksen vaikutusta pinnan kemialliseen koostumukseen, karheuteen, kostutusominaisuuksiin ja vapaaseen pintaenergiaan. SA -pintaisille titaanikiekoille kasvatettiin sekä S. mutans biofilmi että F. nucleatum ja P. gingivalis kaksoisbiofilmit. Titaanikiekot hiekkapuhallettiin bioaktiivisella lasijauheella, minkä jälkeen kiekot siirrettiin anaerobiseen viljelykammioon 5 tunniksi S. mutans biofilmiä ja 21 tunniksi F. nucleatum ja P. gingivalis kaksoisbiofilmiä tutkittaessa. Biofilmien eliminoituminen selvitettiin pyyhkäisyelektronimikroskooppikuvista ja viljelytekniikoita käyttäen. Bioaktiivisella lasilla hiekkapuhallettujen SA -pintaisten titaanikiekkojen vaikutus veren hyytymiseen selvitettiin tutkimalla veren adsorbanssia spektrofotometrisesti useissa eri aikapisteissä. MC3T3-E1 pre-osteoblastisolujen elinkyky ja jakautuminen SA -pintaisilla titaaninäytteillä selvitettiin ennen ja jälkeen bioaktiivisella lasilla tehtyä ilma-abraasiokäsittelyä. Ilma-abraasiokäsittelyt tehtiin samalla tavalla kaikissa kokeissa. Titaanikiekot hiekkapuhallettiin 20 sekunnin ajan 90º kulmassa 3 mm etäisyydellä 4 baarin ilmanpainetta käyttäen. Bioktiivisella lasilla käsitellyillä pinnoilla todettiin tilastollisesti merkitsevä S. mutans bakteerien elinkykyä ja biofilmin muodostumista heikentävä vaikutus. Bioaktiivisella lasilla tehty ilma-abraasio käsittely poisti tehokkaammin sekä S. mutans että F. nucleatum ja P. gingivalis kaksoisbiofilmit SA -pintaisilta titaanikiekoilta inertillä lasilla tehtyyn ilma-abraasio käsittelyyn verrattuna. Käsitellyillä pinnoilla ei havaittu merkitseviä eroja veren hyytymisnopeudessa, sillä veri hyytyi kaikilla testikappaleilla 40 minuutissa. Ilma-abraasio käsittely tasoitti SA -pintaisten titaanikiekkojen pinnan, paransi pintojen kosteutusta ja lisäsi vapaan pintaenergian määrää kaikilla käsittelyillä. MC3T3-E1 solujen määrä oli suurempi Zn4 tai 45S5 bioaktiivisilla laseilla hiekkapuhalletuilla SA -pintaisilla titaanikiekoilla verrattuna inertillä lasilla hiekkapuhallettuihin titaanikiekkoihin Laserkonfokaalipyyhkäisymikroskooppikuvat osoittivat, että pre-osteoblastit eivät levinneet SA -pintaisilla tai bioaktiivisella lasilla hiekkapuhalletuilla titaanipinnoilla yhtä hyvin kuin kontrollina toimineilla peitelaseilla. Bioaktiivisilla 45S5 ja Zn4 laseilla hiekkapuhalletuilla pinnoilla pre-osteoblastisolut kuitenkin jakautuivat parhaiten 24 tunnin aikana ja muuttuivat viljelyperiodin pidentyessä morfologialtaan kehrämäisiksi. Tulosten perusteella voidaan todeta, että bioaktiivisella lasilla tehtävä ilma-abraasiokäsittely on potentiaalinen peri-implantiitin hoitomenetelmä. Hoitomenetelmän teho on kuitenkin vielä osoitettava in vivo olosuhteissa ennen lopullisten johtopäätösten tekoa

Osteoblast Attachment on Titanium Coated with Hydroxyapatite by Atomic Layer Deposition

Background: The increasing demand for bone implants with improved osseointegration properties has prompted researchers to develop various coating types for metal implants. Atomic layer deposition (ALD) is a method for producing nanoscale coatings conformally on complex three-dimensional surfaces. We have prepared hydroxyapatite (HA) coating on titanium (Ti) substrate with the ALD method and analyzed the biocompatibility of this coating in terms of cell adhesion and viability. Methods: HA coatings were prepared on Ti substrates by depositing CaCO3 films by ALD and converting them to HA by wet treatment in dilute phosphate solution. MC3T3-E1 preosteoblasts were cultured on ALD-HA, glass slides and bovine bone slices. ALD-HA and glass slides were either coated or non-coated with fibronectin. After 48h culture, cells were imaged with scanning electron microscopy (SEM) and analyzed by vinculin antibody staining for focal adhesion localization. An 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) test was performed to study cell viability. Results: Vinculin staining revealed similar focal adhesion-like structures on ALD-HA as on glass slides and bone, albeit on ALD-HA and bone the structures were thinner compared to glass slides. This might be due to thin and broad focal adhesions on complex three-dimensional surfaces of ALD-HA and bone. The MTT test showed comparable cell viability on ALD-HA, glass slides and bone. Conclusion: ALD-HA coating was shown to be biocompatible in regard to cell adhesion and viability. This leads to new opportunities in developing improved implant coatings for better osseointegration and implant survival

Osteoblast Attachment on Titanium Coated with Hydroxyapatite by Atomic Layer Deposition

Background: The increasing demand for bone implants with improved osseointegration properties has prompted researchers to develop various coating types for metal implants. Atomic layer deposition (ALD) is a method for producing nanoscale coatings conformally on complex three-dimensional surfaces. We have prepared hydroxyapatite (HA) coating on titanium (Ti) substrate with the ALD method and analyzed the biocompatibility of this coating in terms of cell adhesion and viability. Methods: HA coatings were prepared on Ti substrates by depositing CaCO3 films by ALD and converting them to HA by wet treatment in dilute phosphate solution. MC3T3-E1 preosteoblasts were cultured on ALD-HA, glass slides and bovine bone slices. ALD-HA and glass slides were either coated or non-coated with fibronectin. After 48h culture, cells were imaged with scanning electron microscopy (SEM) and analyzed by vinculin antibody staining for focal adhesion localization. An 344,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) test was performed to study cell viability. Results: Vinculin staining revealed similar focal adhesion-like structures on ALD-HA as on glass slides and bone, albeit on ALD-HA and bone the structures were thinner compared to glass slides. This might be due to thin and broad focal adhesions on complex three-dimensional surfaces of ALD-HA and bone. The MTT test showed comparable cell viability on ALD-HA, glass slides and bone. Conclusion: ALD-HA coating was shown to be biocompatible in regard to cell adhesion and viability. This leads to new opportunities in developing improved implant coatings for better osseointegration and implant survival.Peer reviewe

Osteoblast Attachment on Titanium Coated with Hydroxyapatite by Atomic Layer Deposition

Background: The increasing demand for bone implants with improved osseointegration properties has prompted researchers to develop various coating types for metal implants. Atomic layer deposition (ALD) is a method for producing nanoscale coatings conformally on complex three-dimensional surfaces. We have prepared hydroxyapatite (HA) coating on titanium (Ti) substrate with the ALD method and analyzed the biocompatibility of this coating in terms of cell adhesion and viability. Methods: HA coatings were prepared on Ti substrates by depositing CaCO3 films by ALD and converting them to HA by wet treatment in dilute phosphate solution. MC3T3-E1 preosteoblasts were cultured on ALD-HA, glass slides and bovine bone slices. ALD-HA and glass slides were either coated or non-coated with fibronectin. After 48h culture, cells were imaged with scanning electron microscopy (SEM) and analyzed by vinculin antibody staining for focal adhesion localization. An 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) test was performed to study cell viability. Results: Vinculin staining revealed similar focal adhesion-like structures on ALD-HA as on glass slides and bone, albeit on ALD-HA and bone the structures were thinner compared to glass slides. This might be due to thin and broad focal adhesions on complex three-dimensional surfaces of ALD-HA and bone. The MTT test showed comparable cell viability on ALD-HA, glass slides and bone. Conclusion: ALD-HA coating was shown to be biocompatible in regard to cell adhesion and viability. This leads to new opportunities in developing improved implant coatings for better osseointegration and implant survival

Effect of bioactive glass air-abrasion on Fusobacterium nucleatum and Porphyromonas gingivalis biofilm formed on moderately rough titanium surface

This aim of this study was to investigate the effects of three types of air-abrasion particles on dual-species biofilms of Fusobacterium nucleatum and Porphyromonas gingivalis, both of which were cultured on sandblasted and acid-etched (SA) titanium discs. Out of 24 SA discs with biofilm, 18 were exposed to either air-abrasion using Bioglass 45S5 (45S5 BG; n = 6), novel zinc (Zn)-containing bioactive glass (Zn4 BG; n = 6), or inert glass (n = 6). The efficiency of biofilm removal was evaluated using scanning electron microscopy (SEM) imaging and culturing techniques. Air-abrasion using 45S5 BG or Zn4 BG demonstrated a significant decrease in the total number of viable bacteria compared to discs air-abraded with inert glass or intact biofilm without abrasion. Moreover, P. gingivalis could not be detected from SEM images nor culture plates after air-abrasion with 45S5 BG or Zn4 BG. The present study showed that air-abrasion with 45S5 or Zn4 bioactive glasses can successfully eradicate dual-biofilm of F. nucleatum and P. gingivalis from sandblasted and acid-etched titanium discs.</p

Osteoblast Attachment on Titanium Coated with Hydroxyapatite by Atomic Layer Deposition

Background: The increasing demand for bone implants with improved osseointegration properties has prompted researchers to develop various coating types for metal implants. Atomic layer deposition (ALD) is a method for producing nanoscale coatings conformally on complex three-dimensional surfaces. We have prepared hydroxyapatite (HA) coating on titanium (Ti) substrate with the ALD method and analyzed the biocompatibility of this coating in terms of cell adhesion and viability.Methods: HA coatings were prepared on Ti substrates by depositing CaCO3 films by ALD and converting them to HA by wet treatment in dilute phosphate solution. MC3T3-E1 preosteoblasts were cultured on ALD-HA, glass slides and bovine bone slices. ALD-HA and glass slides were either coated or non-coated with fibronectin. After 48h culture, cells were imaged with scanning electron microscopy (SEM) and analyzed by vinculin antibody staining for focal adhesion localization. An 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) test was performed to study cell viability.Results: Vinculin staining revealed similar focal adhesion-like structures on ALD-HA as on glass slides and bone, albeit on ALD-HA and bone the structures were thinner compared to glass slides. This might be due to thin and broad focal adhesions on complex three-dimensional surfaces of ALD-HA and bone. The MTT test showed comparable cell viability on ALD-HA, glass slides and bone.Conclusion: ALD-HA coating was shown to be biocompatible in regard to cell adhesion and viability. This leads to new opportunities in developing improved implant coatings for better osseointegration and implant survival.</p

Effect of bioactive glass air-abrasion on the wettability and osteoblast proliferation on sandblasted and acid-etched titanium surfaces

The aim of this study was to evaluate the hydrophilicity, surface free energy, and proliferation and viability of human osteoblast-like MC3T3-E1 cells on sandblasted and acid-etched titanium surfaces after air-abrasion with 45S5 bioactive glass, zinc-containing bioactive glass, or inert glass. Sandblasted and acid-etched titanium discs were subjected to air-abrasion with 45S5 bioactive glass, experimental bioactive glass (Zn4), or inert glass. Water contact angles and surface free energy were evaluated. The surfaces were studied with preosteoblastic MC3T3-E1 cells. Air-abrasion with either type of glass significantly enhanced the hydrophilicity and surface free energy of the sandblasted and acid-etched titanium discs. The MC3T3-E1 cell number was higher for substrates air-abraded with Zn4 bioactive glass and similar to that observed on borosilicate coverslips (controls). Confocal laser scanning microscopy images showed that MC3T3-E1 cells did not spread as extensively on the sandblasted and acid-etched and bioactive glass-abraded surfaces as they did on control surfaces. However, for 45S5- and Zn4-treated samples, the cells spread most at the 24 h time point and changed their morphology to more spindle-like when cultured further. Air-abrasion with bioactive glass and inert glass was shown to have a significant effect on the wettability and surface free energy of the surfaces under investigation. Osteoblast cell proliferation on sandblasted and acid-etched titanium discs was enhanced by air-abrasion with 45S5 bioactive glass and experimental Zn4 bioactive glass compared with air-abrasion with inert glass or no air-abrasion

Antibacterial properties of bioactive glass particle abraded titanium against Streptococcus mutans

The purpose of this study was to evaluate effects of titanium surfaces air-abraded with particles of Bioglass® 45S5 and three-ZnO and SrO doped compositions on the viability, adhesion and biofilm formation of Streptococcus mutans. A statistically significant decrease in the viability of S. mutans was observed for all titanium discs air-particle abraded with the BAGs (p S. mutans adhesion on titanium surfaces treated with different glasses (p = 0.964). Static SBF immersion experiments showed that after 2 and 48 h the BAG doped with 4 mol% ZnO demonstrated the highest Zn2+ ion concentration released into SBF (0.2 mg L−1). 45S5 BAG demonstrated the highest statistically significant increase in the pH throughout the 120 min of static immersion (p S. mutans and they suppressed S. mutans biofilm formation. The antimicrobial activity of 45S5 BAG was attributed to high pH whereas for the Zn-containing BAGs antimicrobial activity was due to steady release of Zn2+ into the interfacial solution.</p

Monocyte Differentiation on Atomic Layer-Deposited (ALD) Hydroxyapatite Coating on Titanium Substrate

Hydroxyapatite (HA; Ca10(PO4)6(OH)2) coating of bone implants has many beneficial properties as it improves osseointegration and eventually becomes degraded and replaced with new bone. We prepared HA coating on a titanium substrate with atomic layer deposition (ALD) and compared monocyte differentiation and material resorption between ALD-HA and bone. After stimulation with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-B ligand (RANKL), human peripheral blood monocytes differentiated into resorbing osteoclasts on bovine bone, but non-resorbing foreign body cells were observed on ALD-HA. The analysis of the topography of ALD-HA and bone showed no differences in wettability (water contact angle on ALD-HA 86.2° vs. 86.7° on the bone), but the surface roughness of ALD-HA (Ra 0.713 µm) was significantly lower compared to bone (Ra 2.30 µm). The cellular reaction observed on ALD-HA might be a consequence of the topographical properties of the coating. The absence of resorptive osteoclasts on ALD-HA might indicate inhibition of their differentiation or the need to modify the coating to induce osteoclast differentiation

Monocyte Differentiation on Atomic Layer-Deposited (ALD) Hydroxyapatite Coating on Titanium Substrate

Hydroxyapatite (HA; Ca10(PO4)6(OH)2) coating of bone implants has many beneficial properties as it improves osseointegration and eventually becomes degraded and replaced with new bone. We prepared HA coating on a titanium substrate with atomic layer deposition (ALD) and compared monocyte differentiation and material resorption between ALD-HA and bone. After stimulation with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-B ligand (RANKL), human peripheral blood monocytes differentiated into resorbing osteoclasts on bovine bone, but non-resorbing foreign body cells were observed on ALD-HA. The analysis of the topography of ALD-HA and bone showed no differences in wettability (water contact angle on ALD-HA 86.2° vs. 86.7° on the bone), but the surface roughness of ALD-HA (Ra 0.713 µm) was significantly lower compared to bone (Ra 2.30 µm). The cellular reaction observed on ALD-HA might be a consequence of the topographical properties of the coating. The absence of resorptive osteoclasts on ALD-HA might indicate inhibition of their differentiation or the need to modify the coating to induce osteoclast differentiation