Notes: As an integrated structure, it requires no subsequent abutment selection and features simplified surgical procedures. However, it has limited flexibility and imposes stricter requirements on oral conditions. It is only suitable for patients with sufficient and well-shaped alveolar bone as well as simple occlusal relationships, and shall be used only after rigorous clinical assessment by dentists.
II. Implant Surface Treatment Technologies
1. SLA: Large-grit Sandblasted and Acid-etched
1. Processing Technology
Pure titanium implants are first treated with high-pressure sandblasting using large alumina particles, followed by deep etching with mixed strong acids. The final surface presents a microscale dual-rough topography, consisting of macroscopic pits (10–50 μm) and microscopic micropores (1–3 μm).
2. Surface Characteristics
It features moderate roughness with Ra value of approximately 1.5–3.0 μm and a greatly enlarged surface area. This structure facilitates the adhesion, proliferation and mineralization of osteoblasts. It delivers a moderate osseointegration rate and excellent long-term stability.
2. SLActive: Hydrophilic Activated SLA
1. Processing Technology
The implant undergoes standard SLA procedures including large-grit sandblasting and mixed acid etching. It is then cleaned and packaged in a nitrogen inert atmosphere to prevent surface oxidation, and preserved in isotonic saline. The core objective is to avoid hydrocarbon contamination and maintain high surface energy and superior hydrophilicity.
2. Surface Characteristics
Its microscopic structure is identical to conventional SLA, while the key difference lies in full surface hydrophilicity. Blood spreads rapidly upon contact and blood clots form at an extremely fast rate. Protein adsorption speed is several times higher than that of traditional SLA, laying a solid foundation for early osseointegration.
3. Advantages
It significantly accelerates early osseointegration, enabling early loading within 4 to 6 weeks after surgery. It is well suited for patients with compromised bone healing capacity, such as those with osteoporosis, diabetes and smokers. It also ensures higher safety for immediate implantation and immediate loading protocols.
3. Anodized Surface
1. Processing Technology
The titanium implant is used as the anode and placed in an acidic electrolyte for electrification. A porous titanium dioxide (TiO2) film is formed on the implant surface via electrochemical oxidation. The resultant structure has uniform pores of 1–10 μm in diameter with a film thickness of about 1–2 μm.
2. Surface Characteristics
The surface presents a regular honeycomb porous structure without sharp edges and corners. It has excellent soft tissue compatibility and causes minimal irritation to gingiva. Besides, it possesses stable chemical properties with strong corrosion resistance and wear resistance.
3. Advantages
It has prominent osteoconductivity and ensures steady bone deposition. Supported by abundant long-term clinical follow-up data, it boasts reliable safety and stability. It is particularly favorable for aesthetic zones and patients with thin gingiva, yielding more natural soft tissue contours postoperatively.
4. RBM: Resorbable Blast Media
1. Processing Technology
Calcium phosphate particles are adopted as the blasting medium to replace traditional alumina particles. After high-pressure sandblasting, residual calcium phosphate particles on the surface dissolve and are absorbed by human tissues spontaneously. A mild acid etching may be applied subsequently, or the process can skip acid etching entirely. The major merit is a mild treatment process with no risk of residual strong acid.
2. Surface Characteristics
It has moderately low roughness and barely irritates soft tissues. The surface remains clean without foreign residues, achieving superior biocompatibility. This technology prioritizes soft tissue adaptation while meeting basic osseointegration requirements.
5. SA: Sandblasted and Double Acid-etched
1. Processing Technology
Alumina particles are first used for sandblasting to create a primary rough surface, followed by two-step acid etching (usually hydrochloric acid then sulfuric acid, or staged etching with mixed acids). A uniform microscale rough surface is formed, with roughness slightly lower than that of Western SLA technology.
2. Surface Characteristics
Its lower roughness matches the moderate bone density of Asian populations. It provides reliable osseointegration stability, features simplified processes and outstanding cost performance. The surface has no prominent sharp structures and causes little irritation to soft tissues.
6. CA Surface / Calcium Ion-activated Hydrophilic Surface
This technology combines SA sandblasting & acid etching, hydrophilic modification and calcium ion activation. It focuses on accelerating early osseointegration and is applicable to cases with average bone volume.
1. Processing Technology
The implant is firstly processed with standard SA sandblasting and acid etching to form a microscale rough surface. Afterwards, it is immersed in calcium-containing solution for surface activation. Hydrophilic packaging is applied to maintain high wettability and accelerate blood infiltration.
2. Surface Characteristics
The surface is highly hydrophilic, allowing rapid blood spreading and clot formation. Loaded with calcium ions, it speeds up hydroxyapatite deposition and promotes early osteogenesis. It combines the mechanical interlocking effect of rough topography and the rapid healing advantage of hydrophilic surfaces.
7. Micro-nano Composite Surface
1. Processing Technology
A microscale rough surface with macro pits and micropores is first fabricated via standard SLA treatment. On the basis of the microstructures, nanostructures are further introduced by electrochemical treatment or etching. A hierarchical microstructure consisting of macro pits, micropores and nano cilia/nano dots is finally obtained.
2. Surface Characteristics
The surface exhibits excellent protein adsorption capacity and can rapidly adsorb growth factors in blood. It upregulates the expression of osteogenic genes and accelerates the proliferation and differentiation of osteoblasts. Additionally, it possesses anti-inflammatory and antibacterial properties, which helps reduce the risk of peri-implantitis.
8. HA (Hydroxyapatite) Coating
As a classic bioactive coating technology, it mimics the composition of human bone tissue and features prominent early osteoinductivity. Traditional thick coatings are gradually phased out, while modified ultra-thin coatings have become the mainstream.
1. Processing Technology
- Hydroxyapatite (HA) powder is melted and uniformly sprayed onto the surface of titanium implants by plasma spraying.
- A ceramic coating with a thickness of tens of micrometers is formed, whose composition is similar to human bone tissue.
2. Surface Characteristics
It has extremely high bioactivity. With a composition close to natural bone, it can rapidly induce the adhesion and proliferation of osteoblasts and initiate osseointegration at an accelerated rate.
Conventional thick coatings carry risks of peeling and degradation. Currently, modified ultra-thin crystalline calcium phosphate (CaP) coatings are widely adopted.
9. Electrochemical Nano-oxidation / Composite Oxidation Surface
This technology performs nano-scale enhancement based on SLA surfaces, combining long-term stability and rapid healing, and is applicable to mid-to-high-end implant restorations.
1. Processing Technology
The SLA process is applied first to create microscale roughness for reliable mechanical interlocking. Afterwards, an additional nano-oxide layer is deposited on the microstructured surface through electrochemical oxidation. The resulting composite structure integrates micro roughness and nano oxide layer, achieving a balance between mechanical stability and bioactivity.
2. Surface Characteristics
The micro rough structure provides sufficient mechanical interlocking to ensure long-term stability. The nano-oxide layer improves surface bioactivity and hydrophilicity, and facilitates early osseointegration.
This document is compiled for professional learning in stomatology, intended only for academic exchange and study, and does not serve as clinical diagnosis and treatment advice. Any errors or imperfections are open to comments and corrections from colleagues.
