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Effect of surface texturing on the bonding strength of titanium–porcelain
Author's Accepted Manuscript
Effect of surface texturing on the bonding strength of titanium-porcelain Litong Guo, Junlong Tian, Jing Wu, Baoe Li, Yabo Zhu, Cheng Xu, Yinghuai Qiang
www.elsevier.com/locate/matlet
PII: DOI: Reference:
S0167-577X(14)01010-6 http://dx.doi.org/10.1016/j.matlet.2014.05.189 MLBLUE17121
To appear in:
Materials Letters
Received date: 20 February 2014 Accepted date: 31 May 2014 Cite this article as: Litong Guo, Junlong Tian, Jing Wu, Baoe Li, Yabo Zhu, Cheng Xu, Yinghuai Qiang, Effect of surface texturing on the bonding strength of titanium-porcelain, Materials Letters, http://dx.doi.org/10.1016/j.matlet.2014.05.189 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Effect of Surface Texturing on the Bonding Strength of Titanium-Porcelain Litong Guo1∗, Junlong Tian1, Jing Wu1, Baoe Li2, Yabo Zhu1, Cheng Xu1, Yinghuai Qiang1 (1 China University of Mining and Technology, Xuzhou 221116, P.R. China) (2 Key laboratory of inorganic coating materials, Chinese Academy of Sciences, Shanghai 200050, P.R. China) Abstract The effects of surface texture in form of elliptical dimples on the titanium-porcelain bonding strength were investigated. The surface texture was mechanically engraved at all combinations of three different area fractions and two different depths. The morphologies of the titanium surface were studied by scanning electron microscopy. The adhesion between the Ti and porcelain was evaluated by three point bending test. With the area fraction and depth of the dimples increasing, the surface roughness increased accordingly, whilst the contact angle value decreased. Compared to the sandblasted and polished groups, the surface roughness and wettability of the textured groups had been significantly improved, which led to the increased mechanical interlocking between the porcelain and titanium. Keywords: Titanium; Biomaterials; Surfaces; Texture; Adhesion
Corresponding author:
Litong Guo, Ph. D., Associate professor, School of Materials Science & Engineering, China University of Mining and Technology, Xuzhou 221116, P. R. China, E-mail: [email protected]. Tel: +86 516 83591939, Fax: +86 516 83591870.
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1 Introduction Titanium has been used as important dental material due to its excellent mechanical strength, corrosion resistance and biocompatibility [1, 2]. However, inferior bonding strength in titanium-porcelain systems compared to the conventional metal-porcelain systems is still a major problem for its application [3-5]. The titanium-porcelain bonding strength is influenced by chemical bonding, mechanical bonding, van der Waals forces, and mismatching of thermal expansion coefficient between porcelain and titanium [6]. Among those factors, the mechanical bonding is mainly depended on the surface roughness of titanium [5]. To improve the surface roughness of titanium, several methods had been introduced, including sandblasting with Al2O3 particles, acid etching, anodization and surface texturing (ST) [8]. In the sandblasting process, Al2O3 particles will be embedded into the titanium surface and produce stress at the Ti-porcelain interface, which would result in fracture of Ti-porcelain [5]. ST is a viable and low cost surface treatment which simultaneously improves surface roughness, tribological performance and osseointegration [8-11]. However, there were no available reports on ST to improve titanium-porcelain bonding strength. The aim of this research was to improve surface roughness of titanium by ST mechanically engraved, and evaluate the effect of shape parameters of ST on the bonding strength of Ti-porcelain.
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2 Experimental Procedures 2.1. Preparation of specimens ASTM grade 2 titanium was cast, ground with SiC paper and polished to prepare plate-shaped specimens (25 mm × 3 mm × 0.5 mm). The elliptical dimples were machined on the titanium specimens by a circuit board engraver (ZY-3220B, Guangzhou Zhongyue Numerical Control Equipment Ltd., China). The parameters of the ST are shown in Table 1. After machining, the specimens were slightly ground and polished to remove the burrs around the rim of the dimples. Then specimens were cleaned by ultrasonic agitation in deionized H2O and acetone for 5 min, respectively. The groups with no treatment and sandblasting were employed as the control groups. Then the textured groups and control groups were both treated by anodization processes. 2.2 Preparation of titanium–porcelain test specimens Thin layers of bonding, opaque and dentin porcelains (GG Titanium Porcelains, Xi’an Jiaotong University, China) were subsequently fired on the central of the specimens, respectively, in a porcelain oven furnace (Multimat 99, Dentsply, American). The thicknesses of bonding, opaque and dentin porcelain were controlled to 0.1 mm, 0.3 and 0.6 mm, respectively. 2.3 Bonding Strength tests Each specimen was positioned on supports with a span distance of 20 mm in a universal testing machine (DSS-25T, Shimadzu, Japan) at a crosshead speed of 1.5 mm/min. The force was applied with porcelain side opposite the center support until fracture. From the three point bending tests the bondng strength were calculate according to ISO 9693 [12].
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2.4. Surface characterization The surface roughness of titanium was measured using a probe-style contact profilometer (JB-4C, Shanghai Taiming Optical Instrument Co. Ltd, China). The contact angle of the textured surface was measured on a contact angle measuring instrument (JC2000C1, Shanghai Zhongchen Digital Technical Equipment Ltd., China). The morphologies and structure of the titanium surface were studied by FE-SEM (Sirion200, FEI, USA). The titanium-porcelain interface after three point bending test was studied by SEM (JSM–6460, JEOL, Japan) coupled with energy-dispersive spectrometry (EDS) (INCAX–sight, Oxford, England).
3 Results and discussion The schematic of different surface texture patterns is shown in figure 1(a). Three different area fractions of the dimples were used in this research. The F-SEM images of textured Ti surface are shown in figure 1(b), (c) and (d). Figure 1(b) and (c) shows the microdimples are about 150 μm in diameter with the horizontal interval of about 350 μm. Figure 1(d) shows the Ti surface around the dimple was composed of many nano-protuberances. The sizes of the nano-protuberance in figure 1(d) were about 30 nm in diameter. These nano-protuberances formed during anodization process, which would improve the corrosion resistance of titanium. The dimples increase the surface roughness of titanium. In the previous research, the increased surface roughness of titanium increased the contact areas and mechanical bonding between titanium and porcelain [5, 13].
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Table 1 shows the effect of parameters of the ST on surface roughness, wettability and bonding strength. Table 1 shows that the Ra of Ti surface was significantly increased from 0.41μm to 11.35 μm after ST (p<0.05). With the area fraction and depth of the dimples increasing, the surface roughness increased accordingly, whilst the contact angle value decreased. Compared to the sandblasted and polished groups, the surface roughness and wettability of the textured groups had been significantly improved (p<0.05). Compared with the sandblasted and polished groups, the textured groups showed a significant increase (about 20% to 30%) of bonding strength (p<0.05). The increased surface roughness and wettability result in the increased mechanical interlocking between the porcelain and titanium.
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Figure 2 shows the SEM micrograph of Ti surface debonded from porcelain (a) sandblasted and (b) textured surface with area fractions 20% and depth 30 μm. Figure 2(a) showed no evident residual porcelain retained on the sandblasted titanium surface debonded from porcelain. In figure 2(b), greater quantities of residual porcelain islands were found adhering to the textured titanium surface with area fractions 20% and depth 30 μm, attesting a better mechanical performance.
The EDS results based on raster analysis showed that the titanium surface debonded from porcelain in Fig. 2(a) was composed of 6.94 wt% SiO2, 2.13 wt% Al2O3 and 90.93 wt% Ti, which also confirmed that little residual porcelain retained on the sandblasted titanium surface in the control group. It indicated that fracture predominantly occurred at the Ti-TiO2 interface. The EDS results showed that the titanium surface debonded from porcelain in Fig. 2(b) was composed of 36.21 wt%SiO2, 6.94 wt% Al2O3, 1.12 wt% Na2O, 0.78 wt% K2O and 54.4 wt% Ti. The SiO2, Al2O3, Na2O and K2O came from the porcelain, which indicated that the fracture mode was a mixed type. The fracture occurred not only at the titanium surface, but also in bonding porcelain. The textured group showed much higher Si values compared with the sandblasted group, which confirms the superior ceramic adherence [4].
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4 Conclusions The surface roughness of Ti surface was significantly increased after ST. With the area fraction and depth of the dimples increasing, the surface roughness increased accordingly, whilst the contact angle value decreased. Compared to the sandblasted and polished groups, the increased surface roughness and wettability of the textured groups led to the increased mechanical interlocking between the porcelain and titanium. The increased bonding strength will help to increase the life-span of the titanium-porcelain prosthesis. Acknowledgements The authors gratefully acknowledge the Fourth Military Medical University for providing support for porcelain fusion. This work was supported by the National Natural Science Foundation of China (No. 81100789 and 51201056) and the Fundamental Research Funds for the Central Universities (No. 2012QNA04). References [1] Yamazoe J, Nakagawa M, Matono Y, Takeuchi A, Ishikawa K. The development of Ti alloys for dental implant with high corrosion resistance and mechanical strength [J]. Dental Materials Journal, 2007, 26: 260-7. [2] Fischer Y, Ceramic bonding to a dental gold–titanium alloy[J]. Biomaterials, 2002, 23 (5): 1303-11. [3] Troia MG Jr, Henriques GE, Mesquita MF, Fragoso W. The effect of surface modifications on titanium to enable titanium-porcelain bonding [J]. Dental Material, 2008, 24(1): 28-33. [4] Guo LT, Wu HT, Liu XC, Zhu YB, Gao JQ, Guo TW. Effect of fluoride corrosion on the bonding strength of Ti–porcelain under static loads [J]. Materials Letters，2009, 63(28): 2486-2488.
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[5] Guo LT, Liu XC, Gao JQ, Yang JF, Guo TW. Effect of surface modifications to Ti-porcelain bonding strength. Mater & Manufact Proc, 2010, 25, 710-7. [6] Reyes MJ, Oshida Y, Andres CJ, Barco T, Hovijitra S, Brown D. Titanium porcelain system. Part III: effects of surface modification on bondstrengths. Biomed Mater Eng, 2001, 11:117-36. [7] Jeong YH, Kim WG, Choe HC. Electrochemical behavior of nano and femtosecond laser textured titanium alloy for implant surface modification. J Nanosci & Nanotech, 2011, 11: 1581-4. [8] Shalabi MM, Gortemaker A, Van’t Hof MA, Jansen JA, Creugers NH. Implant surface roughness and bone healing: a systematic review. J Dent Res, 2006, 85: 496-500. [9] Costil S, Lamraoui A, Langlade C, Heintz O, Oltra R.
Surface modifications induced by
pulsed-laser texturing—Influence of laser impact on the surface properties. Applied Surface Science, 2014, 288(1): 542-9. [10] Mangano C, Rosa AD, Desiderio V, d'Aquino R, Piattelli A, Francesco FD, Tirino V, Mangano F, Papaccio G. The osteoblastic differentiation of dental pulp stem cells and bone formation on different titanium surface textures. Biomaterials, 2010, 31(13): 3543-51. [11] Prodanov L, Lamers E, Domanski M, Luttge R, Jansen JA, Walboomers XF. The effect of nanometric surface texture on bone contact to titanium implants in rabbit tibia. Biomaterials, 2013, 34(12): 2920-7. [12] ISO 9693. Geneva: International Organization for Standardization, 1999. [13] Thorat SB, Diaspro A, Salerno M. In vitro investigation of coupling-agent-free dental restorative composite based on nano-porous alumina fillers. Journal of Dentistry, 2014, 42(3): 279-286.
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Fig. 1 (a) Schematic of different surface texture patterns (b) FE-SEM images of textured Ti surface with area fractions 15% and depth 30 μm, (c) high magnifications images of the dimple and (d) high magnifications images of Ti surface around the dimple.
Fig.2 SEM photos of Ti surface debonded from porcelain (a) sandblasted and (b) textured surface with area fractions 20% and depth 30 μm.
Table 1 Surface roughness and contact angle of different parameters of the surface texturing Groups 1 2 3 4 5 6 Control (sandblasted) Control (polished)
Area fraction(%) 10 15 20 10 15 20 -----
Size (μm) 150 150 150 150 150 150 -----
Depth(μm)
Ra (μm) 4.54±0.37 6.14±0.43 7.15±0.39 6.92±0.49 8.69±0.54 11.35±0.58 1.86±0.15
Contact Angle (°) 69.47±2.47 67.61±2.24 65.13±2.19 64.89±2.52 61.24±1.88 54.38±1.96 80.16±2.31
bonding strength (MPa) 43.22±3.18 45.37±2.93 46.39±3.82 45.91±3.47 47.49±3.26 48.62±2.62 38.67±2.78
20 20 20 30 30 30 -----
-----
-----
-----
0.41±0.04
85.92±2.75
33.53±3.12
Highlights Surface texturing significantly increased the surface roughness. Surface texturing increased wettability of titanium surface. Surface texturing increased mechanical interlocking between porcelain and titanium.
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Effect of surface texturing on the bonding strength of titanium-porcelain Litong Guo, Junlong Tian, Jing Wu, Baoe Li, Yabo Zhu, Cheng Xu, Yinghuai Qiang
www.elsevier.com/locate/matlet
PII: DOI: Reference:
S0167-577X(14)01010-6 http://dx.doi.org/10.1016/j.matlet.2014.05.189 MLBLUE17121
To appear in:
Materials Letters
Received date: 20 February 2014 Accepted date: 31 May 2014 Cite this article as: Litong Guo, Junlong Tian, Jing Wu, Baoe Li, Yabo Zhu, Cheng Xu, Yinghuai Qiang, Effect of surface texturing on the bonding strength of titanium-porcelain, Materials Letters, http://dx.doi.org/10.1016/j.matlet.2014.05.189 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Effect of Surface Texturing on the Bonding Strength of Titanium-Porcelain Litong Guo1∗, Junlong Tian1, Jing Wu1, Baoe Li2, Yabo Zhu1, Cheng Xu1, Yinghuai Qiang1 (1 China University of Mining and Technology, Xuzhou 221116, P.R. China) (2 Key laboratory of inorganic coating materials, Chinese Academy of Sciences, Shanghai 200050, P.R. China) Abstract The effects of surface texture in form of elliptical dimples on the titanium-porcelain bonding strength were investigated. The surface texture was mechanically engraved at all combinations of three different area fractions and two different depths. The morphologies of the titanium surface were studied by scanning electron microscopy. The adhesion between the Ti and porcelain was evaluated by three point bending test. With the area fraction and depth of the dimples increasing, the surface roughness increased accordingly, whilst the contact angle value decreased. Compared to the sandblasted and polished groups, the surface roughness and wettability of the textured groups had been significantly improved, which led to the increased mechanical interlocking between the porcelain and titanium. Keywords: Titanium; Biomaterials; Surfaces; Texture; Adhesion
Corresponding author:
Litong Guo, Ph. D., Associate professor, School of Materials Science & Engineering, China University of Mining and Technology, Xuzhou 221116, P. R. China, E-mail: [email protected]. Tel: +86 516 83591939, Fax: +86 516 83591870.
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1 Introduction Titanium has been used as important dental material due to its excellent mechanical strength, corrosion resistance and biocompatibility [1, 2]. However, inferior bonding strength in titanium-porcelain systems compared to the conventional metal-porcelain systems is still a major problem for its application [3-5]. The titanium-porcelain bonding strength is influenced by chemical bonding, mechanical bonding, van der Waals forces, and mismatching of thermal expansion coefficient between porcelain and titanium [6]. Among those factors, the mechanical bonding is mainly depended on the surface roughness of titanium [5]. To improve the surface roughness of titanium, several methods had been introduced, including sandblasting with Al2O3 particles, acid etching, anodization and surface texturing (ST) [8]. In the sandblasting process, Al2O3 particles will be embedded into the titanium surface and produce stress at the Ti-porcelain interface, which would result in fracture of Ti-porcelain [5]. ST is a viable and low cost surface treatment which simultaneously improves surface roughness, tribological performance and osseointegration [8-11]. However, there were no available reports on ST to improve titanium-porcelain bonding strength. The aim of this research was to improve surface roughness of titanium by ST mechanically engraved, and evaluate the effect of shape parameters of ST on the bonding strength of Ti-porcelain.
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2 Experimental Procedures 2.1. Preparation of specimens ASTM grade 2 titanium was cast, ground with SiC paper and polished to prepare plate-shaped specimens (25 mm × 3 mm × 0.5 mm). The elliptical dimples were machined on the titanium specimens by a circuit board engraver (ZY-3220B, Guangzhou Zhongyue Numerical Control Equipment Ltd., China). The parameters of the ST are shown in Table 1. After machining, the specimens were slightly ground and polished to remove the burrs around the rim of the dimples. Then specimens were cleaned by ultrasonic agitation in deionized H2O and acetone for 5 min, respectively. The groups with no treatment and sandblasting were employed as the control groups. Then the textured groups and control groups were both treated by anodization processes. 2.2 Preparation of titanium–porcelain test specimens Thin layers of bonding, opaque and dentin porcelains (GG Titanium Porcelains, Xi’an Jiaotong University, China) were subsequently fired on the central of the specimens, respectively, in a porcelain oven furnace (Multimat 99, Dentsply, American). The thicknesses of bonding, opaque and dentin porcelain were controlled to 0.1 mm, 0.3 and 0.6 mm, respectively. 2.3 Bonding Strength tests Each specimen was positioned on supports with a span distance of 20 mm in a universal testing machine (DSS-25T, Shimadzu, Japan) at a crosshead speed of 1.5 mm/min. The force was applied with porcelain side opposite the center support until fracture. From the three point bending tests the bondng strength were calculate according to ISO 9693 [12].
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2.4. Surface characterization The surface roughness of titanium was measured using a probe-style contact profilometer (JB-4C, Shanghai Taiming Optical Instrument Co. Ltd, China). The contact angle of the textured surface was measured on a contact angle measuring instrument (JC2000C1, Shanghai Zhongchen Digital Technical Equipment Ltd., China). The morphologies and structure of the titanium surface were studied by FE-SEM (Sirion200, FEI, USA). The titanium-porcelain interface after three point bending test was studied by SEM (JSM–6460, JEOL, Japan) coupled with energy-dispersive spectrometry (EDS) (INCAX–sight, Oxford, England).
3 Results and discussion The schematic of different surface texture patterns is shown in figure 1(a). Three different area fractions of the dimples were used in this research. The F-SEM images of textured Ti surface are shown in figure 1(b), (c) and (d). Figure 1(b) and (c) shows the microdimples are about 150 μm in diameter with the horizontal interval of about 350 μm. Figure 1(d) shows the Ti surface around the dimple was composed of many nano-protuberances. The sizes of the nano-protuberance in figure 1(d) were about 30 nm in diameter. These nano-protuberances formed during anodization process, which would improve the corrosion resistance of titanium. The dimples increase the surface roughness of titanium. In the previous research, the increased surface roughness of titanium increased the contact areas and mechanical bonding between titanium and porcelain [5, 13].
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Table 1 shows the effect of parameters of the ST on surface roughness, wettability and bonding strength. Table 1 shows that the Ra of Ti surface was significantly increased from 0.41μm to 11.35 μm after ST (p<0.05). With the area fraction and depth of the dimples increasing, the surface roughness increased accordingly, whilst the contact angle value decreased. Compared to the sandblasted and polished groups, the surface roughness and wettability of the textured groups had been significantly improved (p<0.05). Compared with the sandblasted and polished groups, the textured groups showed a significant increase (about 20% to 30%) of bonding strength (p<0.05). The increased surface roughness and wettability result in the increased mechanical interlocking between the porcelain and titanium.
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Figure 2 shows the SEM micrograph of Ti surface debonded from porcelain (a) sandblasted and (b) textured surface with area fractions 20% and depth 30 μm. Figure 2(a) showed no evident residual porcelain retained on the sandblasted titanium surface debonded from porcelain. In figure 2(b), greater quantities of residual porcelain islands were found adhering to the textured titanium surface with area fractions 20% and depth 30 μm, attesting a better mechanical performance.
The EDS results based on raster analysis showed that the titanium surface debonded from porcelain in Fig. 2(a) was composed of 6.94 wt% SiO2, 2.13 wt% Al2O3 and 90.93 wt% Ti, which also confirmed that little residual porcelain retained on the sandblasted titanium surface in the control group. It indicated that fracture predominantly occurred at the Ti-TiO2 interface. The EDS results showed that the titanium surface debonded from porcelain in Fig. 2(b) was composed of 36.21 wt%SiO2, 6.94 wt% Al2O3, 1.12 wt% Na2O, 0.78 wt% K2O and 54.4 wt% Ti. The SiO2, Al2O3, Na2O and K2O came from the porcelain, which indicated that the fracture mode was a mixed type. The fracture occurred not only at the titanium surface, but also in bonding porcelain. The textured group showed much higher Si values compared with the sandblasted group, which confirms the superior ceramic adherence [4].
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4 Conclusions The surface roughness of Ti surface was significantly increased after ST. With the area fraction and depth of the dimples increasing, the surface roughness increased accordingly, whilst the contact angle value decreased. Compared to the sandblasted and polished groups, the increased surface roughness and wettability of the textured groups led to the increased mechanical interlocking between the porcelain and titanium. The increased bonding strength will help to increase the life-span of the titanium-porcelain prosthesis. Acknowledgements The authors gratefully acknowledge the Fourth Military Medical University for providing support for porcelain fusion. This work was supported by the National Natural Science Foundation of China (No. 81100789 and 51201056) and the Fundamental Research Funds for the Central Universities (No. 2012QNA04). References [1] Yamazoe J, Nakagawa M, Matono Y, Takeuchi A, Ishikawa K. The development of Ti alloys for dental implant with high corrosion resistance and mechanical strength [J]. Dental Materials Journal, 2007, 26: 260-7. [2] Fischer Y, Ceramic bonding to a dental gold–titanium alloy[J]. Biomaterials, 2002, 23 (5): 1303-11. [3] Troia MG Jr, Henriques GE, Mesquita MF, Fragoso W. The effect of surface modifications on titanium to enable titanium-porcelain bonding [J]. Dental Material, 2008, 24(1): 28-33. [4] Guo LT, Wu HT, Liu XC, Zhu YB, Gao JQ, Guo TW. Effect of fluoride corrosion on the bonding strength of Ti–porcelain under static loads [J]. Materials Letters，2009, 63(28): 2486-2488.
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[5] Guo LT, Liu XC, Gao JQ, Yang JF, Guo TW. Effect of surface modifications to Ti-porcelain bonding strength. Mater & Manufact Proc, 2010, 25, 710-7. [6] Reyes MJ, Oshida Y, Andres CJ, Barco T, Hovijitra S, Brown D. Titanium porcelain system. Part III: effects of surface modification on bondstrengths. Biomed Mater Eng, 2001, 11:117-36. [7] Jeong YH, Kim WG, Choe HC. Electrochemical behavior of nano and femtosecond laser textured titanium alloy for implant surface modification. J Nanosci & Nanotech, 2011, 11: 1581-4. [8] Shalabi MM, Gortemaker A, Van’t Hof MA, Jansen JA, Creugers NH. Implant surface roughness and bone healing: a systematic review. J Dent Res, 2006, 85: 496-500. [9] Costil S, Lamraoui A, Langlade C, Heintz O, Oltra R.
Surface modifications induced by
pulsed-laser texturing—Influence of laser impact on the surface properties. Applied Surface Science, 2014, 288(1): 542-9. [10] Mangano C, Rosa AD, Desiderio V, d'Aquino R, Piattelli A, Francesco FD, Tirino V, Mangano F, Papaccio G. The osteoblastic differentiation of dental pulp stem cells and bone formation on different titanium surface textures. Biomaterials, 2010, 31(13): 3543-51. [11] Prodanov L, Lamers E, Domanski M, Luttge R, Jansen JA, Walboomers XF. The effect of nanometric surface texture on bone contact to titanium implants in rabbit tibia. Biomaterials, 2013, 34(12): 2920-7. [12] ISO 9693. Geneva: International Organization for Standardization, 1999. [13] Thorat SB, Diaspro A, Salerno M. In vitro investigation of coupling-agent-free dental restorative composite based on nano-porous alumina fillers. Journal of Dentistry, 2014, 42(3): 279-286.
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Fig. 1 (a) Schematic of different surface texture patterns (b) FE-SEM images of textured Ti surface with area fractions 15% and depth 30 μm, (c) high magnifications images of the dimple and (d) high magnifications images of Ti surface around the dimple.
Fig.2 SEM photos of Ti surface debonded from porcelain (a) sandblasted and (b) textured surface with area fractions 20% and depth 30 μm.
Table 1 Surface roughness and contact angle of different parameters of the surface texturing Groups 1 2 3 4 5 6 Control (sandblasted) Control (polished)
Area fraction(%) 10 15 20 10 15 20 -----
Size (μm) 150 150 150 150 150 150 -----
Depth(μm)
Ra (μm) 4.54±0.37 6.14±0.43 7.15±0.39 6.92±0.49 8.69±0.54 11.35±0.58 1.86±0.15
Contact Angle (°) 69.47±2.47 67.61±2.24 65.13±2.19 64.89±2.52 61.24±1.88 54.38±1.96 80.16±2.31
bonding strength (MPa) 43.22±3.18 45.37±2.93 46.39±3.82 45.91±3.47 47.49±3.26 48.62±2.62 38.67±2.78
20 20 20 30 30 30 -----
-----
-----
-----
0.41±0.04
85.92±2.75
33.53±3.12
Highlights Surface texturing significantly increased the surface roughness. Surface texturing increased wettability of titanium surface. Surface texturing increased mechanical interlocking between porcelain and titanium.
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