Open hour: senin - sabtu 09:00:00 - 20:00:00; minggu & tanggal merah tutup

Fig. 8. EDS 5 min : Achieving surface chemical an...

Fig. 8. EDS 5 min Fig. 8. EDS 5 min

Fig. 7. EDS 3 min : Achieving surface chemical an...

Fig. 7. EDS 3 min Fig. 7. EDS 3 min

Fig. 6. EDS 1 min : Achieving surface chemical an...

Fig. 6. EDS 1 min Fig. 6. EDS 1 min

Fig. 5. EDS control : Achieving surface chemical a...

Fig. 5. EDS control Fig. 5. EDS control

Fig. 4. Group 4—5 min : Achieving surface chemi...

Fig. 4. Group 4—5 min Fig. 4. Group 4—5 min

Fig. 3. Group 3—3 min : Achieving surface chemi...

Fig. 3. Group 3—3 min Fig. 3. Group 3—3 min

Fig. 2. Group 2—1 min : Achieving surface chemi...

Fig. 2. Group 2—1 min Fig. 2. Group 2—1 min

Fig. 1. Group control : Achieving surface chemical...

Fig. 1. Group control Fig. 1. Group control

Table 9 Chemical analysis of surface (group 4 spec...

Element Weight % Atoms % Carbon 15.07 26.19 ...

Table 8 Chemical analysis of surface (group 4 spec...

Element Weight % Atoms % Carbon 10.43 23.42 ...

Table 7 Chemical analysis of surface (group 3 spec...

Element Weight % Atoms % Carbon 4.12 15.29 ...

Table 6 Chemical analysis of surface (group 3 spec...

Element Weight % Atoms % Carbon 4.79 18.86 ...

Table 5 Chemical analysis of surface (group 2 spec...

Element Weight % Atoms % Carbon 8.54 31.34 ...

Table 4 Chemical analysis of surface (group 2 spec...

Element Weight % Atoms % Carbon 4.47 19.93 ...

Table 3 Chemical analysis of surface (group 1 spec...

Element Weight % Atoms % Carbon 8.02 38.2 ...

Table 2 Chemical analysis of surface (group 1 spec...

Element Weight % Atoms % Carbon 8.22 37.21 ...

Table 1 Distribution of groups : Achieving surface...

Groups Plasma electrolytic oxidation—time (min) Voltage (V) Current (A) 1 – –   2 1 ΔU = 160 to 200 V ≅0.18 3 3 ΔU = 160 to 280 V ≅0.19 4 5 ΔU = 160 to 300 V ≅0.18   Table 1 Distribution of groups

About this article : Achieving surface chemical an...

Goularte, M.A.P.C., Barbosa, G.F., da Cruz, N.C. et al. Achieving surface chemical and morphologic alterations on tantalum by plasma electrolytic oxidation. Int J Implant Dent 2, 12 (2016). https://doi.org/10.1186/s40729-016-0046-2 Download citation Received: 18 November 2015 Accepted: 12 April 2016 Published: 16 April 2016 DOI: https://doi.org/10.1186/s40729-016-0046-2

Rights and permissions : Achieving surface chemica...

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were m...

Additional information : Achieving surface chemica...

The authors declare that they have no competing interests. MAPCG contributed to the concept/design, data collection, data analysis/interpretation, drafting of the article, critical revision of the article, and approval of the article. GFB carried out the data analysis/interpretation, drafting of the article, critical revision of the article, and approval of the article. NCC contributed to the dat...

Author information : Achieving surface chemical an...

Department of Prosthodontics, Implantology Pontifical Catholic University of Rio Grande do Sul - PUCRS, Av. Ipiranga, 6681 Prédio 06, Partenon, CEP: 90619-900, Porto Alegre, RS, Brazil Marcelo Augusto Pinto Cardoso Goularte Clinical Department, Universidade Luterana do Brasil - Torres (ULBRA-TORRES), Rua Universitária, 1900, Parque do Balonismo, CEP 95560-000, Torres, RS, Brazil Gustavo Frain...

References : Achieving surface chemical and morpho...

Yerokhin AL, Nie X, Leyland A, Matthews A, Dowey SJ. Plasma electrolysis for surface engineering. Surf Coat Technol. 1999;122(2-3):73–93. doi:10.1016/S0257-8972(99)00441-7. Hosoki M, Nishigawa K, Miyamoto Y, Ohe G, Matsuka Y. Allergic contact dermatitis caused by titanium screws and dental implants. J Prosthodont Res. 2016. doi: 10.1016/j.jpor.2015.12.004. [Epub ahead of print]. Goutam M, Giri...

References : Achieving surface chemical and morpho...

Gittens RA, Olivares-Navarrete R, Cheng A, Anderson DM, McLachlan T, Stephan I, et al. The roles of titanium surface micro/nanotopography and wettability on the differential response of human osteoblast lineage cells. Acta Biomater. 2013;9(4):6268–77. doi:10.1016/j.actbio.2012.12.002. Epub 2012 Dec 8. Bauer S, Schmuki P, von der Mark K, et al. Engineering biocompatible implant surfaces part I: ...

Discussion and conclusions : Achieving surface che...

Thus, this study has examined the possibility of activating an alteration surface in tantalum using the anodizing process, which is effective in other metals like titanium. From our findings, it was possible to develop time exposure protocols in order to obtain conductive surface alterations similar to those already available from some of the largest manufacturers of oral implants. Scanning electr...

Discussion and conclusions : Achieving surface che...

The search for new biomaterials and biocompatible metals has always been a common objective of human rehabilitation research centers. In implant dentistry, titanium has successfully established itself as the material of choice for dental implants. However, several studies have reported cases of metal allergy caused by titanium-containing materials [15–17] and some immune dysfunctions in certain ...

Results : Achieving surface chemical and morpholog...

Tables 2 and 3 show similar rates among the chemical elements present on the non-treated tantalum surface—group 1 (Fig. 5). In Tables 4 and 5 (group 2), calcium (Ca) is included. The rates for the other chemical elements are similar to the rates in group 1 (Fig. 6). In Tables 6 and 7, group 3 sample shows the basic chemicals present in previous groups and similar rates (Fig. 7). Two chemic...

Results : Achieving surface chemical and morpholog...

The analysis of the images obtained by scanning electron microscopy confirmed the changes on the surface of tantalum strips according to different exposure times. In Fig. 1, we can observe Ta surface with grooves resulting from the machining of the metal with no surface treatment. As the magnitude increases, the image shows the lines pattern with its peculiar characteristics from the manufacturin...

Methods : Achieving surface chemical and morpholog...

Within a 50-mL tank, the electrolytic solution as described above received a voltage variation of 160 V initial tension at zero time and a final tension at the preset end-time for each group of samples. There was a gradual increase in voltage due to the maintenance of a fairly constant current at around 0.15 to 0.25 A. The electrolytic solution was periodically changed to prevent solution satura...

Methods : Achieving surface chemical and morpholog...

We used 60 strip-shaped samples of tantalum with the following dimensions: 7 mm wide, 11 mm long, and 0.01 mm thick (Kurt J. Lesker Company—USA, 99.95 % purity). The samples were washed in distilled water and placed in an ultrasonic tank containing acetone (Ultra Sonic-1440 Plus—Odontobrás, Ribeirão Preto/SP, Brazil) to remove residues. Then, they were divided into four groups: in group ...

Background : Achieving surface chemical and morpho...

In this way and following the successful results already obtained with Titanium, this study aimed to develop an oxidized surface layer on Tantalum samples and, subsequently, analyze the samples’ topography and levels of salt deposition using an electronic microscope.

Background : Achieving surface chemical and morpho...

The use of materials that come into direct contact with human tissues such as the bone requires maximum biological security. These materials remain for a long period of time or even indefinitely in the human body, and no negative reactions, like toxicity or carcinogenic effects, shall be acceptable. For this reason, biocompatibility of new materials has been widely studied, and only after a lot o...

Abstract : Achieving surface chemical and morpholo...

Search for materials that may either replace titanium dental implants or constitute an alternative as a new dental implant material has been widely studied. As well, the search for optimum biocompatible metal surfaces remains crucial. So, the aim of this work is to develop an oxidized surface layer on tantalum using plasma electrolytic oxidation (PEO) similar to those existing on oral implants bee...

Fig. 4. Effects of PRP, PRGF, A-PRF, and CGF on th...

Fig. 4. Effects of PRP, PRGF, A-PRF, and CGF on the proliferation of human periosteal cells. Cells were treated with PRP preparations, PRGF preparations, A-PRF extracts, or CGF extracts at the indicated doses for 48 h in 1 % FBS-containing medium. *P 

Fig. 3. Concentrations of the pro-inflammatory cyt...

Fig. 3. Concentrations of the pro-inflammatory cytokines (IL-1β, IL-6) in PRP, PRGF, A-PRF, and CGF preparations (n = 20) Fig. 3. Concentrations of the pro-inflammatory cytokines (IL-1β, IL-6) in PRP, PRGF, A-PRF, and CGF preparations (n = 20)

Table 1 Centrifugation conditions for preparation ...

Preparation type Models Rotor Radius (mm) Rotational speed ...

About this article : Growth factor and pro-inflamm...

Masuki, H., Okudera, T., Watanebe, T. et al. Growth factor and pro-inflammatory cytokine contents in platelet-rich plasma (PRP), plasma rich in growth factors (PRGF), advanced platelet-rich fibrin (A-PRF), and concentrated growth factors (CGF). Int J Implant Dent 2, 19 (2016). https://doi.org/10.1186/s40729-016-0052-4 Download citation Received: 21 June 2016 Accepted: 18 Au...

Rights and permissions : Growth factor and pro-inf...

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were...

Author information : Growth factor and pro-inflamm...

You can also search for this author in PubMed Google Scholar You can also search for this author in PubMed Google Scholar Correspondence to Tomoyuki Kawase.

Author information : Growth factor and pro-inflamm...

Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan Hideo Masuki, Toshimitsu Okudera, Taisuke Watanebe, Masashi Suzuki, Kazuhiko Nishiyama & Hajime Okudera Bioscience Medical Research Center, Niigata University Medical and Dental Hospital, Niigata, Japan Koh Nakata Department of Dentistry, National Yang-Ming University, Taipei, Taiwan Chen-Yao Su Division of Oral Bioengineering, Instit...

References : Growth factor and pro-inflammatory cy...

Kobayashi M, Kawase T, Okuda K, Wolff LF, Yoshie H. In vitro immunological and biological evaluations of the angiogenic potential of platelet-rich fibrin preparations: a standardized comparison with PRP preparations. Int J Implant Dent. 2015;1:31. Sonnenschein SK, Meyle J. Local inflammatory reactions in patients with diabetes and periodontitis. Periodontol 2000. 2015;69:221–54. Download refer...

References : Growth factor and pro-inflammatory cy...

Clipet F, Tricot S, Alno N, Massot M, Solhi H, Cathelineau G, Perez F, De Mello G, Pellen-Mussi P. In vitro effects of Choukroun’s platelet-rich fibrin conditioned medium on 3 different cell lines implicated in dental implantology. Implant Dent. 2012;21:51–6. Gassling VL, Acil Y, Springer IN, Hubert N, Wiltfang J. Platelet-rich plasma and platelet-rich fibrin in human cell culture. Oral Surg ...

References : Growth factor and pro-inflammatory cy...

Kawase T. Platelet-rich plasma and its derivatives as promising bioactive materials for regenerative medicine: basic principles and concepts underlying recent advances. Odontology. 2015;103:126–35. Anitua E. The use of plasma-rich growth factors (PRGF) in oral surgery. Pract Proced Aesthet Dent. 2001;13:487–93. Choukroun J. Advanced PRF, &i-PRF: platelet concentrates or blood concentrates? J...

Abbreviations : Growth factor and pro-inflammatory...

Acid citrate dextrose solution Analysis of variance Advanced platelet-rich fibrin A-PRF extract Concentrated growth factors CGF extract Enzyme-linked immunosorbent assay Interleukin-1β Interleukin-6 Platelet-derived growth factor-BB Platelet Plasma rich in growth factors Platelet-rich plasma Red blood cell Transforming growth factor-β1 Vascular endothelial growth factor White blo...

Conclusions : Growth factor and pro-inflammatory c...

The present study clearly demonstrated that both A-PRF and CGF preparations contained significant amounts of growth factors, which makes us to believe that A-PRF and CGF preparations would not only function as a scaffolding material but also as a reservoir to deliver certain growth factors at the site of application. Accordingly, it is expected that these two preparations are more potently capable...

Discussion : Growth factor and pro-inflammatory cy...

In the previous study [12], we found that PRP and A-PRF preparations exert distinguishable actions on periosteal cell proliferation. Because both IL-1β and IL-6 are known to be produced by WBCs [23], and because WBCs are not included in PRGF preparations, we thought that the bi-phasic effects of PRP preparations may be attributed to WBCs. Furthermore, if WBCs are highly concentrated in A-PRF, it ...

Discussion : Growth factor and pro-inflammatory cy...

Although the growth factor contents in PRF and CGF preparations and their bioactivities have been demonstrated in in vitro studies by several independent groups [8–11, 13–20], many clinicians still believe that the regenerative effects of PRF/CGF are solely due to fibrin clots. We speculate that this discrepancy may be caused by two major factors. First, the initial report on PRF by Choukroun ...

Results : Growth factor and pro-inflammatory cytok...

Numbers of platelets in PRP and PRGF preparations are shown in Fig. 1 (upper panel). Platelets were significantly concentrated both in the PRP and PRGF preparations, and the concentration rate of PRP preparations was substantially higher than that of PRGF preparations (8.79-fold vs. 2.84-fold). Numbers of platelets in A-PRF and CGF preparations calculated by the indirect subtraction method are al...

Methods : Growth factor and pro-inflammatory cytok...

Because alveolar periosteum is closely contributed to periodontal skeletal tissue regeneration, we used human alveolar bone-derived periosteal cells for evaluation of efficacy of the PRP derivatives. The periosteal cells were obtained and expanded as described below. With informed consent, human periosteum tissue segments were aseptically dissected from the periodontal tissues of the healthy bucca...

Methods : Growth factor and pro-inflammatory cytok...

As described previously [7, 9], blood samples (~9.5 mL) collected without anticoagulants using vacuum plain glass tubes (A-PRF+: Jiangxi Fenglin Medical Technology Co. Ltd, Fengcheng, China) or conventional vacuum plain glass tube (Plain BD Vacutainer Tube; Becton, Dickinson and Company, Franklin Lakes, NJ, USA) from the same donors were immediately centrifuged by an A-PRF centrifugation system (...

Methods : Growth factor and pro-inflammatory cytok...

Based on their characteristics and fractionation, the differences among PRP and PRP derivatives are concisely described in our previous article [1]. As previously described [5, 6], blood samples (11.5 mL) were collected using syringes or vacuum blood collection tubes equipped with 18G needles from seven non-smoking, healthy, middle-aged, male volunteers (37 to 68 years old) three times with a 2...

Background : Growth factor and pro-inflammatory cy...

Platelet-rich plasma (PRP) was originally demonstrated to be effective in the operation of alveolar ridge augmentation and immediately spread to the fields of periodontal and oral maxillofacial surgery [1]. This clinical application was endorsed by evidence that several major growth factors are contained at high levels in PRP preparations. However, for some reasons, such as low handling efficiency...

Abstract : Growth factor and pro-inflammatory cyto...

The development of platelet-rich fibrin (PRF) drastically simplified the preparation procedure of platelet-concentrated biomaterials, such as platelet-rich plasma (PRP), and facilitated their clinical application. PRF’s clinical effectiveness has often been demonstrated in pre-clinical and clinical studies; however, it is still controversial whether growth factors are significantly concentrated ...

Fig. 3. Enzymatic degradability of A-PRF, CGF, and...

Fig. 3. Enzymatic degradability of A-PRF, CGF, and PPTF membranes. Each membrane disk (φ8 mm, 1 mm thick) was immersed in PBS containing trypsin and incubated in a CO2 incubator. N = 4. The asterisks represent significant differences (P 

Fig. 2. Representative stress-strain curves for A-...

Fig. 2. Representative stress-strain curves for A-PRF and CGF membranes and mechanical properties (Young’s modulus, strain at break, and maximum stress) of A-PRF, CGF, and PPTF membranes. N = 3–9 Fig. 2. Representative stress-strain curves for A-PRF and CGF membranes and mechanical properties (Young’s modulus, strain at break, and maximum stress) of A-PRF, CGF, and PPTF membranes. N...

Fig. 1. Surface microstructures of A-PRF, CGF, and...

Fig. 1. Surface microstructures of A-PRF, CGF, and fibrin clots prepared by PPP + CaCl2 and PPTF (fibrin clots prepared by PPP and thrombin). Similar observations were obtained from other three independent blood samples. Scale bar = 10 μm. Note: the same magnification (×9000) was used in all the SEM images shown here Fig. 1. Surface microstructures of A-PRF, CGF, and fibrin clots p...

Table 3 Summaries of preparation procedures, relat...

  A-PRF CGF PPTF Centrifugal conditions 198 g × 8 min 692 g × 2 mina ...

Table 2 Comparison of water content of A-PRF, CGF,...

  Wet weight (g) Dry weight (g) Water content (%) A-PRF 1.905 ± 0.416 0.043 ± 0.014* ...

Table 1 Similarity in size and stretching property...

  Size (W × L mm) Stretching (times longer) Number A-PRF 8.6 ± 1.2 × 27.5 ± 3.5 ...

About this article : Mechanical and degradation pr...

Isobe, K., Watanebe, T., Kawabata, H. et al. Mechanical and degradation properties of advanced platelet-rich fibrin (A-PRF), concentrated growth factors (CGF), and platelet-poor plasma-derived fibrin (PPTF). Int J Implant Dent 3, 17 (2017). https://doi.org/10.1186/s40729-017-0081-7 Download citation Received: 29 January 2017 Accepted: 25 April 2017 Published: 02 May 2017 ...

Rights and permissions : Mechanical and degradatio...

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were...

Author information : Mechanical and degradation pr...

You can also search for this author in PubMed Google Scholar You can also search for this author in PubMed Google Scholar You can also search for this author in PubMed Google Scholar You can also search for this author in PubMed Google Scholar Correspondence to Tomoyuki Kawa...

Author information : Mechanical and degradation pr...

Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan Kazushige Isobe, Taisuke Watanebe, Hideo Kawabata, Yutaka Kitamura, Toshimitsu Okudera & Hajime Okudera Division of Dental Implantology, Niigata University Medical and Dental Hospital, Niigata, Japan Kohya Uematsu Division of Periodontology, Institute of Medicine and Dentistry, Niigata University, Niigata, Japan Kazuhiro Okuda Bioscie...

References : Mechanical and degradation properties...

Mosesson MW. Fibrinogen and fibrin structure and functions. J Thromb Haemost. 2005;3:1894–904. Kawase T, Kamiya M, Kobayashi M, Tanaka T, Okuda K, Wolff LF, Yoshie H. The heat-compression technique for the conversion of platelet-rich fibrin preparation to a barrier membrane with a reduced rate of biodegradation. J Biomed Mater Res B Appl Biomater. 2015;103:825–31. Hartshorne J, Gluckman H. A...

References : Mechanical and degradation properties...

Choukroun J, Diss A, Simonpieri A, Girard MO, Schoeffler C, Dohan SL, Dohan AJ, Mouhyi J, Dohan DM. Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part V: histologic evaluations of PRF effects on bone allograft maturation in sinus lift. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;101:299–303. Kawase T. Platelet-rich plasma and its derivatives as promising bioac...

Abbreviations : Mechanical and degradation propert...

Acid citrate dextrose solution Advanced platelet-rich fibrin Concentrated growth factors Platelet-poor plasma-derived, thrombin-activated fibrin Platelet-rich plasma

Conclusions : Mechanical and degradation propertie...

In the mechanical parameters and degradability we tested, CGF membranes were almost identical to A-PRF membranes. In contrast, PPTF membranes were mechanically weaker and highly degradable. Therefore, we conclude that all of these fibrin membranes are tough enough to serve as barrier membranes; however, we should pay attention to their degradability and choose an appropriate membrane type dependin...

Discussion : Mechanical and degradation properties...

Growth factor release is a key function of these fibrin clots for tissue regeneration. Our previous study [16] demonstrated that CGF membranes compressed by the stainless steel compression device contain significantly higher levels of growth factors even after releasing approximately 85% of exudate. Repeated rinsing with PBS failed to completely remove the growth factors from CGF membranes. The ri...

Discussion : Mechanical and degradation properties...

In this study, we found no apparent differences between A-PRF and CGF clot microstructures, especially in fibrin fiber thickness or crosslink density. However, in PPTF clots, which were prepared through direct conversion of fibrinogen by thrombin, fibrin fiber thickness and their crosslink density were substantially thinner and higher, respectively, than those of either A-PTF or CGF clots. This fi...

Results : Mechanical and degradation properties of...

The main purpose of this study was to compare A-PRF with CGF preparations to find possible differences in mechanical properties. As shown in Table 1, the sizes of A-PRF clots compressed to membranes were 8.6 ± 1.2 mm (W) × 27.5 ± 3.5 mm (L) and very similar to those of CGF clots (8.4 ± 0.8 mm × 27.6 ± 2.5 mm). As reference, PPTF membranes were also prepared by ad...

Methods : Mechanical and degradation properties of...

After pipetting the digestion solution, 50 μL of the digestion solution was collected every 20 min and was stored at −20 °C until protein measurement. Protein levels, which can be considered primarily as levels of digested fibrin fiber, were then determined by a BCA protein assay kit (Takara Bio, Kusatsu, Japan). The protein levels at the time point when the initial fibrin disks were comple...

Methods : Mechanical and degradation properties of...

The mechanical properties of gel sheets were measured at a stretching speed of 1 mm/min with a desktop universal testing machine (EZ test; Shimadzu, Kyoto, Japan), of which maximum load cell capacity was 500 N under standard ambient conditions at 25 ± 3 °C and 50 ± 25% RH. The samples were gripped by clamps at each end (using slip-proof rubber sheets to prevent slippage) such that th...

Methods : Mechanical and degradation properties of...

Blood samples were collected from four non-smoking, healthy, male volunteers with ages ranging from 27 to 56 years. Although having lifestyle-related diseases and receiving medication, these donors had no hindrance in daily life. The study design and consent forms for all procedures performed with the study subjects were approved by the ethical committee for human subjects at Niigata University S...

Background : Mechanical and degradation properties...

In this study, we hypothesized that the mechanical properties of the fibrin membrane are closely related to its degradability. We compared these characteristics among A-PRF, CGF, and PPTF membranes through tensile and digestion tests.

Background : Mechanical and degradation properties...

Platelet-rich fibrin (PRF), a self-clotted preparation of platelet-concentrated, blood-derived biomaterials, is prepared solely by contact activation of intrinsic coagulation pathways through centrifugation without addition of coagulation factors [1, 2]. Therefore, the preparation protocol is drastically simplified, and the resulting clot can be handled easily with forceps. PRF is further modified...

Abstract : Mechanical and degradation properties o...

Fibrin clot membranes prepared from advanced platelet-rich fibrin (A-PRF) or concentrated growth factors (CGF), despite their relatively rapid biodegradability, have been used as bioactive barrier membranes for alveolar bone tissue regeneration. As the membranes degrade, it is thought that the growth factors are gradually released. However, the mechanical and degradable properties of these membran...

Fig. 6. Cumulative survival rate of complication-f...

Fig. 6. Cumulative survival rate of complication-free prostheses by a gender (p = 0.1220) and b type of prostheses (p 

Fig. 5. Kaplan-Meier cumulative survival rate of c...

Fig. 5. Kaplan-Meier cumulative survival rate of complication-free prostheses at 10, 15, and 25 years after the prosthesis setting Fig. 5. Kaplan-Meier cumulative survival rate of complication-free prostheses at 10, 15, and 25 years after the prosthesis setting

Fig. 4. Cumulative incidence of peri-implantitis b...

Fig. 4. Cumulative incidence of peri-implantitis by a gender (p = 0.0221), b implant type (p = 0.0128), c implant position (p = 0.2470), d presence of additional soft tissue management (p = 0.2488), and e width of keratinized mucosa around implant (p = 0.0045). Log rank test was used for assessing statistical significance Fig. 4. Cumulative incidence of peri-implantitis by a gender ...

Fig. 3. Cumulative incidence of peri-implantitis :...

Fig. 3. Cumulative incidence of peri-implantitis Fig. 3. Cumulative incidence of peri-implantitis

Fig. 2. Kaplan-Meier cumulative survival rates by ...

Fig. 2. Kaplan-Meier cumulative survival rates by a gender (p = 0.1049), b implant type (p = 0.6259), c implant position (p 

Fig. 1. Kaplan-Meier cumulative survival rate at 1...

Fig. 1. Kaplan-Meier cumulative survival rate at 10, 15, and 25 years after the prosthesis setting Fig. 1. Kaplan-Meier cumulative survival rate at 10, 15, and 25 years after the prosthesis setting

Table 7 Cox regression analyses for cumulative sur...

  Hazard ratio 95% confidence interval p value Gender (male) 1.82 0.946~3.487 ...

Table 6 Cox regression analyses for cumulative inc...

  Hazard ratio 95% confidence interval p value Gender (male) 2.38 1.138~5.362 ...

Table 5 Cox regression analyses for implant surviv...

  Hazard ratio 95% confidence interval p value Gender (male) 1.99 0.538~8.201 ...

Table 4 Distribution of implants by length and loc...

Dia. (mm) Maxilla anterior Maxilla posterior Mandible anterior Mandible posterior Tot...

Table 3 Distribution of implants by diameter and l...

Dia. (mm) Maxilla anterior Maxilla posterior Mandible anterior Mandible posterior Tot...

Table 2 Distribution of implants in situ (n = 22...

Position 1 2 3 4 5 6 ...

Table 1 Age and gender distributions (n = 92) : ...

Age/gender Male Female Total 20–29 3 ...

About this article : Retrospective cohort study of...

Horikawa, T., Odatsu, T., Itoh, T. et al. Retrospective cohort study of rough-surface titanium implants with at least 25 years’ function. Int J Implant Dent 3, 42 (2017). https://doi.org/10.1186/s40729-017-0101-7 Download citation Received: 26 April 2017 Accepted: 28 August 2017 Published: 05 September 2017 DOI: https://doi.org/10.1186/s40729-017-0101-7

Rights and permissions : Retrospective cohort stud...

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were...

Ethics declarations : Retrospective cohort study o...

Tadashi Horikawa, Tetsurou Odatsu, Takatoshi Itoh, Yoshiki Soejima, Hutoshi Morinaga, Naruyoshi Abe, Naoyuki Tsuchiya, Toshikazu Iijima, and Takashi Sawase declare that they have no competing interests. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Author information : Retrospective cohort study of...

You can also search for this author in PubMed Google Scholar TH, TO, and TS initiated and designed the retrospective study and drafted the manuscript including the preparation of figures and tables. TH, TAI, YS, HM, NA, NT, and TOI reviewed the medical records and collected the data. All authors revised the manuscript and approved the final manuscript. Correspondence to...

Author information : Retrospective cohort study of...

Kyushu Implant Research Group, 4-14 Kokaihonmachi, Chuo-ku, Kumamoto, 860-0851, Japan Tadashi Horikawa, Takatoshi Itoh, Yoshiki Soejima, Hutoshi Morinaga, Naruyoshi Abe, Naoyuki Tsuchiya, Toshikazu Iijima & Takashi Sawase Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, 852-8588, Japan Tetsurou Odatsu & Takash...

References : Retrospective cohort study of rough-s...

Pjetursson BE, Thoma D, Jung R, Zwahlen M, Zembic A. A systematic review of the survival and complication rates of implant-supported fixed dental prostheses (FDPs) after a mean observation period of at least 5 years. Clin Oral Implants Res. 2012;23(Suppl 6):22–38. Dorner S, Zeman F, Koller M, Lang R, Handel G, Behr M. Clinical performance of complete dentures: a retrospective study. Int J Prost...

References : Retrospective cohort study of rough-s...

Duda M, Matalon S, Lewinstein I, Harel N, Block J, Ormianer Z. One piece immediately loading implants versus 1 piece or 2 pieces delayed: 3 years outcome. Implant Dent. 2016;25:109–13. Wennerberg A, Albrektsson T. Effects of titanium surface topography on bone integration: a systematic review. Clin Oral Implants Res. 2009;20(Suppl 4):172–84. Teughels W, Van Assche N, Sliepen I, Quirynen M. E...

References : Retrospective cohort study of rough-s...

Dahlin C, Linde A, Gottlow J, Nyman S. Healing of bone defects by guided tissue regeneration. Plast Reconstr Surg. 1988;81:672–6. Boyne PJ, James RA. Grafting of the maxillary sinus floor with autogenous marrow and bone. J Oral Surg. 1980;38:613–6. Hellem S, Karlsson U, Almfeldt I, Brunell G, Hamp SE, Astrand P. Nonsubmerged implants in the treatment of the edentulous lower jaw: a 5-year pro...

References : Retrospective cohort study of rough-s...

Brånemark PI, Adell R, Breine U, Hansson BO, Lindström J, Ohlsson A. Intra-osseous anchorage of dental prostheses. I. Experimental studies. Scand J Plast Reconstr Surg. 1969;3:81–100. Buser D, Sennerby L, De Bruyn H. Modern implant dentistry based on osseointegration: 50 years of progress, current trends and open questions. Periodontol. 2017;73:7–21. Ekelund JA, Lindquist LW, Carlsson GE, ...

Conclusions : Retrospective cohort study of rough-...

In conclusion, our analyses revealed a cumulative survival rate of 89.8% of TPS-surface implants with at least 25 years of functioning. The survival rate of maxillary positioned implants was significantly lower than that of mandibulary positioned implants. The patient gender, implant location, and width of keratinized mucosa affected the rate of peri-implantitis, resulting in late failure. Implan...

Discussion : Retrospective cohort study of rough-s...

We also observed that the tooth-implant-supported prostheses had a lower complication-free rate than implant-supported fixed prostheses due to caries, periodontitis, or the root fracture of abutment teeth. Lang et al. reported that the survival rates of tooth implant-supported fixed partial dentures were 94.1% after 5 years and 77.8% after 10 years of functioning [31], and these results were alm...

Discussion : Retrospective cohort study of rough-s...

Regarding the width of keratinized mucosa, many studies and a review have indicated that the presence of a sufficient width of keratinized mucosa is necessary for maintaining healthy peri-implants [26,27,28,29]. In the present study, when 2 mm of keratinized mucosa was used as the adequate width, the p value was 0.053 (data not shown). This also showed the tendency of the availability of keratini...

Discussion : Retrospective cohort study of rough-s...

Peri-implantitis is the major reason for late failure [13, 14]. The consensus report of the Sixth European Workshop on Periodontology described peri-implant mucositis in approx. 80% of subjects restored with implant, and peri-implantitis in 28–56% of subjects [15]. In the present study, the cumulative incidence of peri-implantitis was 9.5, 15.3, 21.0, and 27.9% at 5, 10, 15, and 25 years after ...

Discussion : Retrospective cohort study of rough-s...

Although all implants used in this study were withdrawn from the market about 20 years before, the longitudinal clinical outcomes over decades will help to better understand potential factors leading to implant failure or complications and assess the safe and predictable use of dental implant. Our analyses revealed a 25-year cumulative survival rate of 89.8% after the prosthesis setting, which se...

Results : Retrospective cohort study of rough-surf...

A total of 48 implants were eventually accompanied by a peri-implant infection: the cumulative incidence of peri-implantitis was 9.5, 15.3, 21.0, and 27.9% at 5, 10, 15, and 25 years after the prosthesis delivery, respectively (Fig. 3). After stepwise backward selection, the gender, implant type, and width of keratinized mucosa showed the significant difference in the cumulative survival rate (T...

Results : Retrospective cohort study of rough-surf...

A total of 92 patients (38 men, 54 women; mean age 54.3 years, range 20–78) received implant-supported prostheses (at the seven private practices) between 1984 and 1990. The distribution of patients by age and gender is presented in Table 1. Fifty-seven patients (140 implants) were considered dropouts due to the fact that no data were obtained at the endpoint, but 25 years had passed since th...

Methods : Retrospective cohort study of rough-surf...

This retrospective observational study was approved by the ethical committee of Nagasaki University (No. 1512). The cases of all of the patients who underwent dental implant treatment with a TPS-surfaced solid-screw implant and whose prosthesis was set in the years 1984–1990 at seven private practices were analyzed. All inserted implants were either a TPS-type (TPS-type, Institute Straumann, Bas...

Background : Retrospective cohort study of rough-s...

Dental implant treatment based on the concept of osseointegration [1] is now a widely accepted restorative treatment for fully and partially edentulous patients. In the earliest days of the use of osseointegrated implants, two different topographies were applied on the implant surfaces: a machined minimally rough titanium surface such as the Brånemark system and a rough microporous titanium plasm...

Abstract : Retrospective cohort study of rough-sur...

The longitudinal clinical outcomes over decades contribute to know potential factors leading to implant failure or complications and help in the decision of treatment alternatives. The cases of all patients who received dental implants treated with titanium plasma-sprayed surfaces and whose prostheses were set in the period 1984–1990 at seven private practices were retrospectively analyzed. The...

Fig. 3. Enzymatic degradability of A-PRF, CGF, and...

Fig. 3. Enzymatic degradability of A-PRF, CGF, and PPTF membranes. Each membrane disk (φ8 mm, 1 mm thick) was immersed in PBS containing trypsin and incubated in a CO2 incubator. N = 4. The asterisks represent significant differences (P 

Fig. 2. Representative stress-strain curves for A-...

Fig. 2. Representative stress-strain curves for A-PRF and CGF membranes and mechanical properties (Young’s modulus, strain at break, and maximum stress) of A-PRF, CGF, and PPTF membranes. N = 3–9 Fig. 2. Representative stress-strain curves for A-PRF and CGF membranes and mechanical properties (Young’s modulus, strain at break, and maximum stress) of A-PRF, CGF, and PPTF membranes. N...

Fig. 1. Surface microstructures of A-PRF, CGF, and...

Fig. 1. Surface microstructures of A-PRF, CGF, and fibrin clots prepared by PPP + CaCl2 and PPTF (fibrin clots prepared by PPP and thrombin). Similar observations were obtained from other three independent blood samples. Scale bar = 10 μm. Note: the same magnification (×9000) was used in all the SEM images shown here Fig. 1. Surface microstructures of A-PRF, CGF, and fibrin clots p...

Table 3 Summaries of preparation procedures, relat...

  A-PRF CGF PPTF Centrifugal conditions 198 g × 8 min 692 g × 2 mina ...

Table 2 Comparison of water content of A-PRF, CGF,...

  Wet weight (g) Dry weight (g) Water content (%) A-PRF 1.905 ± 0.416 0.043 ± 0.014* ...

Table 1 Similarity in size and stretching property...

  Size (W × L mm) Stretching (times longer) Number A-PRF 8.6 ± 1.2 × 27.5 ± 3.5 ...

About this article : Mechanical and degradation pr...

Isobe, K., Watanebe, T., Kawabata, H. et al. Mechanical and degradation properties of advanced platelet-rich fibrin (A-PRF), concentrated growth factors (CGF), and platelet-poor plasma-derived fibrin (PPTF). Int J Implant Dent 3, 17 (2017). https://doi.org/10.1186/s40729-017-0081-7 Download citation Received: 29 January 2017 Accepted: 25 April 2017 Published: 02 May 2017 ...

Rights and permissions : Mechanical and degradatio...

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were...

Author information : Mechanical and degradation pr...

You can also search for this author in PubMed Google Scholar You can also search for this author in PubMed Google Scholar You can also search for this author in PubMed Google Scholar You can also search for this author in PubMed Google Scholar Correspondence to Tomoyuki Kawa...

Author information : Mechanical and degradation pr...

Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan Kazushige Isobe, Taisuke Watanebe, Hideo Kawabata, Yutaka Kitamura, Toshimitsu Okudera & Hajime Okudera Division of Dental Implantology, Niigata University Medical and Dental Hospital, Niigata, Japan Kohya Uematsu Division of Periodontology, Institute of Medicine and Dentistry, Niigata University, Niigata, Japan Kazuhiro Okuda Bioscie...

References : Mechanical and degradation properties...

Mosesson MW. Fibrinogen and fibrin structure and functions. J Thromb Haemost. 2005;3:1894–904. Kawase T, Kamiya M, Kobayashi M, Tanaka T, Okuda K, Wolff LF, Yoshie H. The heat-compression technique for the conversion of platelet-rich fibrin preparation to a barrier membrane with a reduced rate of biodegradation. J Biomed Mater Res B Appl Biomater. 2015;103:825–31. Hartshorne J, Gluckman H. A...

References : Mechanical and degradation properties...

Choukroun J, Diss A, Simonpieri A, Girard MO, Schoeffler C, Dohan SL, Dohan AJ, Mouhyi J, Dohan DM. Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part V: histologic evaluations of PRF effects on bone allograft maturation in sinus lift. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;101:299–303. Kawase T. Platelet-rich plasma and its derivatives as promising bioac...

Abbreviations : Mechanical and degradation propert...

Acid citrate dextrose solution Advanced platelet-rich fibrin Concentrated growth factors Platelet-poor plasma-derived, thrombin-activated fibrin Platelet-rich plasma

Conclusions : Mechanical and degradation propertie...

In the mechanical parameters and degradability we tested, CGF membranes were almost identical to A-PRF membranes. In contrast, PPTF membranes were mechanically weaker and highly degradable. Therefore, we conclude that all of these fibrin membranes are tough enough to serve as barrier membranes; however, we should pay attention to their degradability and choose an appropriate membrane type dependin...

Discussion : Mechanical and degradation properties...

Growth factor release is a key function of these fibrin clots for tissue regeneration. Our previous study [16] demonstrated that CGF membranes compressed by the stainless steel compression device contain significantly higher levels of growth factors even after releasing approximately 85% of exudate. Repeated rinsing with PBS failed to completely remove the growth factors from CGF membranes. The ri...

Discussion : Mechanical and degradation properties...

In this study, we found no apparent differences between A-PRF and CGF clot microstructures, especially in fibrin fiber thickness or crosslink density. However, in PPTF clots, which were prepared through direct conversion of fibrinogen by thrombin, fibrin fiber thickness and their crosslink density were substantially thinner and higher, respectively, than those of either A-PTF or CGF clots. This fi...

Results : Mechanical and degradation properties of...

The main purpose of this study was to compare A-PRF with CGF preparations to find possible differences in mechanical properties. As shown in Table 1, the sizes of A-PRF clots compressed to membranes were 8.6 ± 1.2 mm (W) × 27.5 ± 3.5 mm (L) and very similar to those of CGF clots (8.4 ± 0.8 mm × 27.6 ± 2.5 mm). As reference, PPTF membranes were also prepared by ad...

Methods : Mechanical and degradation properties of...

After pipetting the digestion solution, 50 μL of the digestion solution was collected every 20 min and was stored at −20 °C until protein measurement. Protein levels, which can be considered primarily as levels of digested fibrin fiber, were then determined by a BCA protein assay kit (Takara Bio, Kusatsu, Japan). The protein levels at the time point when the initial fibrin disks were comple...

Methods : Mechanical and degradation properties of...

The mechanical properties of gel sheets were measured at a stretching speed of 1 mm/min with a desktop universal testing machine (EZ test; Shimadzu, Kyoto, Japan), of which maximum load cell capacity was 500 N under standard ambient conditions at 25 ± 3 °C and 50 ± 25% RH. The samples were gripped by clamps at each end (using slip-proof rubber sheets to prevent slippage) such that th...

Methods : Mechanical and degradation properties of...

Blood samples were collected from four non-smoking, healthy, male volunteers with ages ranging from 27 to 56 years. Although having lifestyle-related diseases and receiving medication, these donors had no hindrance in daily life. The study design and consent forms for all procedures performed with the study subjects were approved by the ethical committee for human subjects at Niigata University S...

Background : Mechanical and degradation properties...

In this study, we hypothesized that the mechanical properties of the fibrin membrane are closely related to its degradability. We compared these characteristics among A-PRF, CGF, and PPTF membranes through tensile and digestion tests.

Background : Mechanical and degradation properties...

Platelet-rich fibrin (PRF), a self-clotted preparation of platelet-concentrated, blood-derived biomaterials, is prepared solely by contact activation of intrinsic coagulation pathways through centrifugation without addition of coagulation factors [1, 2]. Therefore, the preparation protocol is drastically simplified, and the resulting clot can be handled easily with forceps. PRF is further modified...

Abstract : Mechanical and degradation properties o...

Fibrin clot membranes prepared from advanced platelet-rich fibrin (A-PRF) or concentrated growth factors (CGF), despite their relatively rapid biodegradability, have been used as bioactive barrier membranes for alveolar bone tissue regeneration. As the membranes degrade, it is thought that the growth factors are gradually released. However, the mechanical and degradable properties of these membran...

Table 7 Cox regression analyses for cumulative sur...

  Hazard ratio 95% confidence interval p value Gender (male) 1.82 0.946~3.487 ...

Table 6 Cox regression analyses for cumulative inc...

  Hazard ratio 95% confidence interval p value Gender (male) 2.38 1.138~5.362 ...

Table 5 Cox regression analyses for implant surviv...

  Hazard ratio 95% confidence interval p value Gender (male) 1.99 0.538~8.201 ...

Table 4 Distribution of implants by length and loc...

Dia. (mm) Maxilla anterior Maxilla posterior Mandible anterior Mandible posterior Tot...

Table 3 Distribution of implants by diameter and l...

Dia. (mm) Maxilla anterior Maxilla posterior Mandible anterior Mandible posterior Tot...

Table 2 Distribution of implants in situ (n = 22...

Position 1 2 3 4 5 6 ...

Table 1 Age and gender distributions (n = 92)

Age/gender Male Female Total 20–29 3 ...

References: Retrospective cohort study of rough-su...

References Brånemark PI, Adell R, Breine U, Hansson BO, Lindström J, Ohlsson A. Intra-osseous anchorage of dental prostheses. I. Experimental studies. Scand J Plast Reconstr Surg. 1969;3:81–100. Buser D, Sennerby L, De Bruyn H. Modern implant dentistry based on osseointegration: 50 years of progress, current trends and open questions. Periodontol. 2017;73:7–...

Conclusions: Retrospective cohort study of rough-s...

Conclusions In conclusion, our analyses revealed a cumulative survival rate of 89.8% of TPS-surface implants with at least 25 years of functioning. The survival rate of maxillary positioned implants was significantly lower than that of mandibulary positioned implants. The patient gender, implant location, and width of keratinized mucosa affected the rate of peri-implantitis, resulting in l...

Results: Retrospective cohort study of rough-surfa...

A total of 48 implants were eventually accompanied by a peri-implant infection: the cumulative incidence of peri-implantitis was 9.5, 15.3, 21.0, and 27.9% at 5, 10, 15, and 25 years after the prosthesis delivery, respectively (Fig. 3). After stepwise backward selection, the gender, implant type, and width of keratinized mucosa showed the significant difference in the cumulative survival rate (T...

Results: Retrospective cohort study of rough-surfa...

Results Patient cohort A total of 92 patients (38 men, 54 women; mean age 54.3 years, range 20–78) received implant-supported prostheses (at the seven private practices) between 1984 and 1990. The distribution of patients by age and gender is presented in Table 1. Fifty-seven patients (140 implants) were considered dropouts due to the fact that no data were obtained at the endpoint, bu...

Methods: Retrospective cohort study of rough-surfa...

Methods Study design This retrospective observational study was approved by the ethical committee of Nagasaki University (No. 1512). The cases of all of the patients who underwent dental implant treatment with a TPS-surfaced solid-screw implant and whose prosthesis was set in the years 1984–1990 at seven private practices were analyzed. All inserted implants were either a TPS-type (TPS-t...

Background: Retrospective cohort study of rough-su...

Background Dental implant treatment based on the concept of osseointegration [1] is now a widely accepted restorative treatment for fully and partially edentulous patients. In the earliest days of the use of osseointegrated implants, two different topographies were applied on the implant surfaces: a machined minimally rough titanium surface such as the Brånemark system and a rough micropor...

Retrospective cohort study of rough-surface titani...

Abstract Background The longitudinal clinical outcomes over decades contribute to know potential factors leading to implant failure or complications and help in the decision of treatment alternatives. Methods The cases of all patients who received dental implants treated with titanium plasma-sprayed surfaces and whose prostheses were set in the period 1984–1990 at seven...

Pendahuluan : Prevotella intermedia & periodontiti...

Asma adalah penyakit yang biasanya ditandai dengan peradangan kronis pada saluran udara dan gejala pernapasan, seperti mengi, ambegan sesak, dada sesak, dan batuk, yang dapat bervariasi dalam intensitas dari masa ke masa. Organisasi Kesarasan Buana memperkirakan bahwa ada 235 juta orang penderita asma pada masa kini. Dengan kata lain, asma menyerang 1% hingga 18% dari populasi bumi. Keparahan ...

Dukungan untuk Titanium Plasma Spray (TPS)

Dukungan untuk Titanium Plasma Spray (TPS) atau Semprotan Plasma Titanium (SPT) telah didokumtasikan dengan baik selama 10 tahun belakangan. Penelitian Bobyn et al mendukung semprotan plasma Titanium ketika mereka mempublikasikan data yang menyatakan bahwa lapisan berpori melingkar (semprotan plasma) memainkan peran penting dalam mencegah akses debris usang ke permukaan endosteal femur. Selain it...

Titanium Plasma Spray (TPS) / Semprotan Plasma Tit...

Tujuan dari setiap pemberian lapisan implant pada keseluruhan sendi artroplasti adalah menyediakan lingkungan biologis yang ramah terhadap tulang.  Hal ini akan memudahkan pertumbuhan tulang ke dalam (in-growth) dan ke luar/ pada permukaan (on-growth) sehingga menghasilkan stabilitas implant jangka panjang .  Bio-Coat merupakan satu di antara sedikit perusahaan internasional yang menawarkan pel...

Permukaan disemprot plasma

Lapisan HA pertama kali diperkenalkan pada pertengahan dasawarsa 1980an untuk memperbaiki fiksasi antara tulang dan implan. Sejak kala itu, bahan ini telah banyak digunakan pada implant ortopedi dan gigi. Penyemprotan plasma komersial merupakan metode yang paling sering digunakan untuk pengendapan lapisan kalsium fosfat, seperti HA. Penyemprotan dilakukan ke bahan implant untuk meningkatkan bioa...

Implan laser & plasma (2)

[Lanjutan] Perlakuan permukaan implant menggunakan semprotan plasma dan laser menghasilkan pengerutan makro. Hal ini membuat implant plasma dan laser jadi tidak lagi dipakai pada abad 21 Masehi sekarang ini.  Karakteristik permukaan implant diharapkan menunjukkan pengaruh biologis selama pemasangan implan dan selama berinteraksi dengan sel-sel. Permukaan implant diharapkan memodifikasi mekanis...

Implan laser & plasma (1)

Ada dua perlakuan permukaan alternatif yang meliputi ablasi laser dan penyemprotan dengan plasma (plasma spraying). Setelah dua perlakuan tersebut, permukaan implant akan mempunyai tingkat kekasaran yang tinggi. Tingkat kekasaran yang dihasilkan dengan teknik ini tergolong dalam tingkat kekasaran makro.  Kekasaran makro berpengaruh pada stabilitas implant dan fiksasi mekanis pembentukan tulang. ...