Key Engineering Materials Vol. 829

Abstract: In order to gain acceleration of the osseointegration process after implant placement, micro retention using inorganic elements such as Hydroxyapatite (HA) were commonly used as a coating material in dental implant. Meanwhile, another inorganic material such as Carbonate Apatite (CO₃Ap) has been known as bone substitute for decades. The purpose of this study is to investigate the flexural strength of Yttria-Stabilized Zirconia (Y-TZP) as dental implant material after being coated with CO₃Ap. Ten specimens of Y-TZP were divided into two groups. The first group was coated with CO₃Ap while other groups without coatings were used as the control. Biaxial flexural strength was determined using piston on three balls-technique and data were evaluated by statistical analysis. The specimens surface were analyzed through images taken by Scanning Electron Microscope (SEM). As the result, this study showed that there was no statistically significant found between the group with coating and the control group (p>0.05). The biaxial flexural strength’s mean of the group with coating and control were 212.80 MPa and 209.35 MPa; while micro Vickers hardness’ means were 229.56 HV and 245.40 HV. It can be concluded that there was no difference in the mean flexural strength between Y-TZP before and after coating.

Abstract: Zirconia-based dental implant in Indonesia is rarely used, especially due to low demand. High production cost makes the price of each zirconia dental implant piece become expensive. The fabrication process of the dental implant using 3 mol% Yttria-stabilized Zirconia (3YSZ) as a starting powder, or being synthesized using ZrCl3 and YCl4 precursor were costly and complicated. The aim of this study is to investigate morphology and phase analysis in the ceramic dental implant which coated with carbonate apatite (CO₃Ap). The industrial 3YSZ powder was compacted using a manual hydraulic press and sintered at 1500°C approximately to 11 mm pellet size. Specimens were pre-treated using 9% hydrofluoric acid (HF) before coated by CO₃Ap, while others without treatment as a control. Then, the specimens were dipped into CO₃Ap suspension and heat treated with temperature variable of 300°C or 500°C. The fabrication of specimen using manual hydraulic press creates monoclinic phase more than expected, while SEM discovered that the particle size of the specimen was 130-500nm. In conclusion, the effective method to coat the ceramic dental implant with CO₃Ap was using 9% HF as a pre-treatment and calcinate in 300°C as confirmed in XRD and EDS.

Abstract: Abstract. Various bioactive calcium phosphates such as hydroxyapatite (HA) and carbonate apatite (CO₃Ap) have been widely studied due to their biocompatibility and osteoconductivity when implanted into bone defects. CO₃Ap has the ability to adapt bone structure and induce bone regeneration; so that it can be categorized as resorbable bioactive materials. CO₃Ap induced much stronger response such as cell adhesion and actin ring formation to osteoclast-like cells rather than HA. The aim of this study is to evaluate the bioactivity on zirconia (Y-TZP) coated with CO₃Ap using simulated body fluid (SBF). Twenty Y-TZP ZrO₂ disks with a 12-mm diameter and 1-mm thickness were employed as the samples. The disks were divided into two groups which the control group without CO₃Ap coating and tested group with CO₃Ap coating. Disks samples are dipped into CO₃Ap suspension for one minute and stored in 37°C incubator for 24 hours. The disks were soaked in SBF for 1, 4, and 7 day(s) at 36.5°C. The obtained apatite crystals were characterized by scanning electron microscopy (SEM). It was found that the apatite formation on the tested group was greater than the control group. The EDS pattern showed the presence of Ca and P on the control and tested group after SBF soaking, which indicate the apatite deposition on the disks’ surface. However, the Ca and P on the tested group was higher compared to the control group. The formation of apatite layer on the disks’ surface is bioactivity indicator of CO₃Ap.

Abstract: In this study, we aimed to introduce bioactivity to bioinert zirconia by performing sandblasting process and subsequently depositing apatite nuclei (AN), which are fine particles of calcium phosphate precipitated by raising pH of SBF, on the surface of the zirconia samples. By soaking the AN treated zirconia samples in SBF, hydroxyapatite formation was observed in 1 day and high hydroxyapatite-forming ability was attained.

Abstract: Dental implants have been widely used to restore missing or damaged teeth. Peri-implantitis is one of the main causes of the implant loss. However, a consensus concerning clinically successful peri-implantitis treatment has not been reached at present. We have newly proposed a treatment method for the peri-implantitis by applying the intraoral laser ablation technique to induce a surface modification of dental implants. In the present study, we investigated the cell adhesion ability of α-tricalcium phosphate (α-TCP) films formed on titanium substrates by an Erbium-Doped:Yttrium, Aluminum, and Garnet (Er:YAG) laser deposition method. Cell adhesion was enhanced by the α-TCP films attached firmly to the substrates using the Er:YAG laser deposition method. This intraoral laser deposition technique can be used to recover the osteointegration ability which was lost by the treatment procedures for peri-implantitis.

Abstract: Three-dimensional (3D) porous carbonated hydroxyapatite (CHA) scaffolds were successfully prepared using polyurethane (PU) replication technique. Two sets of porous scaffolds were prepared using as-synthesized and as-calcined CHA powder as the main component of the slurry. The effect of the condition of starting material was investigated in terms of structure, phase purity, crystallinity and morphology of the fabricated porous scaffolds. Regardless of the condition of starting material used, the porous scaffolds fabricated was single phase B-type CHA and free of secondary phases. Interestingly, scaffolds made of as-calcined CHA powder (SC scaffolds) showed a smoother surface and more solidified struts when compared to as-synthesized CHA powder (SA scaffolds). This is attributed to the state of semi-crystalline phase of the as-calcined powder being amorphous phase. SC scaffold was found to be better scaffold with respect to handling, compaction strength and microstructure with better strut properties.

Abstract: Bone defect is a common problem in the field of dentistry. The defect can be solved bytissue engineering. One component of tissue engineering is scaffold. Carbonate apatite is the main material used because it has an organic components similar to human bones. The carbonate apatite combined with gelatin and chitosan can be used as a scaffold for tissue engineering. The aim of thisstudy is to know the exact ratio of the carbonate apatite, chitosan-gelatine (CA:Ch-GEL) scaffold on the compressive strength and porosity size as biomaterial candidates in tissue engineering. Scaffold was synthesized from CA:Ch-GEL with different ratios of 50:50, 60:40, 70:30 and 80:20 withfreeze drying method. Fourier Transform Infared Spectroscopy (FTIR) was used CA:Ch-GEL scaffold functional group identification. Scaffold mechanical test was performed using an Autograph while a porosity test was performed using Scanning Electron Microscope. All data wereanalyzed by ANOVA followed by Tukey HSD test. Scaffold has a compressive strength ranges 4.02 - 11.35 MPa, with porous ranges 19,18 mm – 52,59 mm at 50:50, 60:40, 70:30 and 80:20 ratios. CA:Ch-GEL scaffold at all ratios can be used as biomaterials in tissue engineering

Abstract: Metakaolin-based porous geopolymer had been successfully developed using aluminum powder by creating bubbles in the structure. These structures were required to mimic the spongy bone thus may be applied as bone substitute materials. It was conducted by adding the aluminum powder in the mixture of Metakaolin (MK) and Alkaline Activator (AA) (NaOH solution and sodium silicate) with ratio 1:1, 1:1,5, 1: 2, 1:2,5 and 1:3 then namely sample A-E respectively. The slurry was then poured into mold 30 x 30 x 30 mm³. Samples were let harden and heated in the oven 80°C for 4 hours prior to demolding. Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) were used to observe the morphology of porosity resulted in the samples and to characterize the crystallinity of the samples. The results showed porous metakaolin geopolymer of sample A had the most similarity with the human spongy bone (80-400 µm). Along with an increase in the amount of AA, crystallinity of albite show a decrease of intensity. This study concluded the porous metakaolin geopolymer obtained was potential to be used as a bone substitutes materials.

Abstract: Introduction. Synthetic coral scaffold is fabricated the mimicking of natural sea coral as a scaffold for bone regeneration [1]. Scaffold is performing functions as a micro environment for cells attachment, growth, proliferates, differentiates until it can form new bone tissue. The proper design is needed to produce the scaffold [2]. The purpose of this study was to investigate the characteristics of synthetic coral scaffold for micro environment of cells by observing cell attachment, hydrophobicity, and scaffold porosity. Experimental. Synthetic coral scaffold consists of bovine gelatin dan CaCO3 by weight, the concentration that be used are 4:6. Sodium citrate is used as dispersant. Thick film like scaffold was prepared for this study [1,3]. Vero cell line was used for observing cell attachment to investigate the biocompatibility the scaffold. The hydrophobicity was observed with distilled water droplets dripped on the scaffold surface, be analyzed in a photograph taken by the camera and then measured the angle. Percentage of porosity was measured using Archimedes law in absolute ethanol. Results and Discussion. Vero cells attached successfully into scaffold. Cell viability percentage is 91,77 % from the absorbance value of the MTT assay. It presented that the scaffold has biocompatibility character. However, the percentage of porosity is 55,85%, so the scaffold has enough porosity for cell attachment. Porosity serves for the diffusion of nutrients, gases and removes the residual metabolism resulting from cell activity that has grown on scaffold. The good porosity value of the scaffold is 50-90%. The higher the porosity value the better the scaffold. Hydrophobicity scaffold appears from the contact angle of 81.4°, the cohesion is greater than the adhesion. This shows the greater synthetic coral scaffold hydrophobicity, which is affected by surface roughness from scaffold porosity. The greater hydrophobicity will also prolong the degradation of the scaffold, thereby enabling cells to proliferate, differentiate and produce bone matrix. Conclusions. Synthetic coral scaffold provides the micro environment for cell, high hydrophobicity allows longer degradation for proliferation and differentiation of bone cells, and porosity that allows cells to be inserted within the scaffold.

Abstract: The incidence of dentoalveolar fracture in children is high about 18% because they are often active, lack of body coordination, and immature mental. The dentoalveolar fractures treatment to the children differs from adults, because of the immature bone structure. The purpose of this study is to investigate the treatment of dentoalveolar fracture in child patient using fixed orthodontic appliance. A 15-year-old boy treated with braces caused by malocclusion class 1 Angle type 1. The child suffers from dentoalveolar fracture of the mandibular anterior tooth and mandibular alveolar bone injury after a motorcycle accident. Fortunately, the patient was using an orthodontic fixed appliance that served as a splinting so that severe damage could be prevented. Treatment: the wound was cleaned by betadine antiseptic solution, and braces bonding on the labial of anterior teeth. The lingual region was splinted with wire as 0.7 SS combined with composite resin to make splinting stronger. The patient was given 500mg amoxicillin and 500mg ibuprofen. Wire SS 0.016 is indicated to have superior strength, and the strength remains a support in fixed orthodontic therapy because the stainless steel alloys are of "18-8" austenitic type contain chromium (7-25%), Nickel (8-25% ) and Carbon (1-2%). Chromium in this stainless steel alloy customs a thin oxide layer which blocks the diffusion of oxygen into the alloy and allows the corrosion resistance of the alloy. Stainless steel is introduced for the use of creating appliances. Archwires have high stiffness, low springiness, corrosion resistance, low range and good formability. These wires are often less expensive than the other ones and they can be readily used as archwires in an orthodontic treatment and splinting as well. After two months of splinting treatment, the tooth position approximately back to normal; there was unification alveolar bone in the radiographic evaluation. Dentoalveolar fracture treatment is to restore the teeth and alveolar bone in order that dentoalveolar structure to function properly, and aesthetic function is achieved.