Surface Treatment – SLA

Sandblasted, Large-Grit, Acid-Etched, SuperHydrophilicity-Activated Surface Treatment

SLA-SH® Features

Hydrophilicity by activation with neutralization solution & bioactive material coating
Sandblasted with Biocompatible grits
Macro-pore & Micro-pore of Ti-Oxide layer mimicking the etched enamel rod of tooth
Even distribution of roughness through the whole portion of Implant Surface
No destruction or alteration of the surface are caused even with torque force at 120 N.cm
Acceleration of Osseointegration and Maximizatio of BIC
Hydrophilicity by activation with neutralization solution & bioactive material coating
SLA-SH® is applied for All of the COWELL® Implant Systems
up to 98,8% survival rate after 5 and 10 year follow-up

1. Evaluation

Using SEM (Scanning Electron Microscope) Images

SLA-SH® Surface magnified X300, 1,000 and 3,000


To other SLA treated implants currently sold in the market





  • Surface treatment patterns were observed on electron microscope photographs of 5,000 magnifications for top parts of the implants.
  • Sand-blasted surface conditions were observed in the product A, B and C due to insufficient acid etching patterns in deep parts as SLA-SH® is sandblasted with Biocompatible grits with even particle size unlike others are done with Alumina.
  • The entire surface of the SLA-SH® treated implant showed uniform acid etching patterns. This implies that the acid etching of the SLA-SH® surface is perfect.

2. Evaluation using SSEM

(Stereo Scanning Electron Microscope) 3D images

SLA-SH® Surface


To other SLA treated implants currently sold in the market

  • Uniform distribution of Macro-pore and Micro-pore
  • Roughness average of the A, B and C 1.08~3.11um, too low or too high. However, which of SLA-SH® showed 1.90um


Upper Ra : 2.47㎛
Lower Ra : 3.11㎛
Deviation : 0.64㎛


Upper Ra : 1.07㎛
Lower Ra : 1.13㎛
Deviation : 0.06㎛


Upper Ra : 2.65㎛
Lower Ra : 2.09㎛
Deviation : 0.56㎛


Upper Ra : 2.65㎛
Lower Ra : 2.09㎛
Deviation : 0.56㎛

3. The surface activity

Increased due to the great surface wetness

Contact angle measurement evaluation result for the saline solution

After SLA treatment (133.06°)

After hydrophilicity activation treatment (36°)

After superhydrophilicity activation treatment (9°)

A after neutralization process and bioactive material coating treatment, the sample became extremely hydrophilic and the surface energy was increased, which facilitated expedition of osteoblast activation to be fused to the bone faster

Relation between surface wetness and roughness

After SLA treatment (Ra: 1.78㎛)

After hydrophilicity activation treatment (Ra: 1.80㎛)

Physicochemical alternation of surface by hydrophilicity activation treatment

Name Start BE Pake BE End BE
C1s 290 284,6 280,5
O1s 535,3 530,42 525,6
Ti2P 468,78 458,78 450,4


After SLA treatment

Name Start BE Pake BE End BE
C1s 290,46 284,6 284,6
O1s 538,8 533,73 529,3
Ti2P 468,2 456,76 453,4


After hydrophilicity activation treatment

  • Surface wetness was improved by increased surface energy of C1s, O1s and Ti2p after hydrophilicity activation treatment
  • To maintain and even to enhance surface wetness, superhydrophilicy activation treatment was carried out and contamination by carbon in the
    atmosphere is prevented during packing and sterilization

4. Its safety has been proven

Through perfect cleaning with an automated system

Comparison of surface element tests through X-ray diffraction

Comparison of surface element tests (X-ray Photo-electron Spectroscopy, XPS)

Sample C1s O1s Ti2p Si2p M1S
A 34.12 45.05 15.11 5.24 0,47
B 31.84 46.49 15.22 4.87 1,57
C 32.19 47.58 17.58 2,65 ND
SLA-SH® 27.19 50,81 17.61 ND ND
  • Quantitative analysis of each surface element found 30% carbon, 47% oxygen, 16% titanium, and 4% silicon in all products.
  • For SLA-SH®, they only consisted of carbons(C1s), oxygen(O1s), and titanium(Ti2p).
  • Sodium hydroxide, the main element of the alkali washing solution, combined with silicon(Si) to form water-soluble Na2SiO2(OH)2·4H2O(water glass), which removed the other elements.

Comparison of elution tests using combustion ion chromatography

Sample F- Cl- NO 2 – SO 4 2 – Br NO 3 PO 4 3 –
A ND 0,024 0,027 0,002 ND 0,031 ND
B ND 0,027 0,019 0,002 ND 0,030 ND
C ND 0,071 0.020 0,002 ND 0,023 ND
  • Similar ions were detected in all the products, but they are not harmful to human because their elements and quantities do not affect the human body and those have been proven in many studies.
  • For SLA-SH®, no other elements except for NO3- were detected. Alkali washing completely removed the SO42- and Cl- ions of sulfuric acid and hydrochloric acid, which are used for heated acid etching because they form water-soluble salts of Na2SO4 and NaCl.
  • No elements that interfere with osteo anagenesis were found, which showed that the cleansing process was perfectly carried out.