Tissue-Level vs. Bone-Level Implants

Understanding the Differences – Leveraging Biological Advantages

In implant dentistry, two fundamental implant designs have been established: bone-level and tissue-level implants. 
Each design follows a distinct surgical and prosthetic protocol.
It has implications for soft tissue stability, crestal bone preservation, esthetics, and long-term success.

This article outlines both implant types in detail.
It also explains why, from a biological and clinical standpoint, the tissue-level concept offers advantages – especially when working with zirconia implants.

What Are Bone-Level Implants? 

Bone-level implants are placed at the level of crestal bone. The implant shoulder sits flush with or slightly below the bone crest.
A separate abutment is then connected, indicating that the implant-abutment interface is located at or below the bone level.

Key Characteristics

• Placement at crestal bone level 
• Two-piece design with separate abutment 
• Implant–abutment connection located at or subcrestal to bone 
• Used in esthetic zone and other regions 

Potential Challenges

• Micro-movement or microgaps at the implant-abutment interface 
• Risk of bacterial infiltration 
• Crestal bone remodeling and gingival ressecion 
• Repeated soft tissue manipulation during uncovering and abutment changes 

Historically, bone-level systems have evolved primarily within titanium implantology.
Subcrestal placement is often required to mask the metallic shoulder in the esthetic zone to avoid gray shadows in patients with a thin gingival profile.

What Are Tissue-Level Implants? 

Tissue-level implants are placed such that the implant shoulder is positioned within the soft tissue.
Therefore, The implant-prosthetic interface is located above the crestal bone.

Key Characteristics

• Placement at soft tissue level 
• Transmucosal healing 
• Implant shoulder positioned outside the crestal bone 
• Potentially lower impact on crestal bone levels

The core principle of the tissue-level concept is to respect the biological width from the outset and avoid disturbing the critical bone-soft tissue interface.

The Decisive Difference: Biology 

The fundamental distinction between bone- and tissue-level implants is not primarily mechanical but biological. 

With bone-level implants, the implant-abutment interface lies at or near the crestal bone. Even minimal microgaps or bacterial colonization may contribute to inflammatory responses, which could affect crestal bone. 

In tissue-level designs, this interface is positioned coronally, away from the sensitive bone area.
This may support:

• Maintaining crestal bone 
• Preserving biological width 
• Minimizing manipulation of peri-implant soft tissue 

From a long-term stability and peri-implant health perspective, the tissue-level principle provides clear biological benefits. 

Why Tissue Level Is Especially Critical for Zirconia Implants 

While bone-level positioning is often necessary in titanium systems for esthetic masking, the paradigm shifts fundamentally when working with zirconia.

Zirconia enables a biologically distinct approach.

1. The Zirconia-Epithelial Attachment

Soft tissue attaches to the zirconia material. Histological studies have demonstrated stable epithelial and connective tissue adhesion to zirconia implant surfaces, often described as zirconia epithelial attachment.¹^-²

This can contributo to:

• A more stable soft tissue interface around the implant collar 
• May support local defense against bacterial colonization 
• No need for a critical subcrestal interface 

Placing a zirconia implant at the bone level may compromise this soft tissue interface.

2. A Wider — Not Narrower — Cervical Design 

Many titanium implants feature a narrow transition zone. In contrast, zirconia tissue level implants are designed with a wider cervical collar. 

A wider cervical collar may help support:³^-⁴

• Soft tissue stability
• Maintain papilla height 
• Contribute to favorable esthetic outcomes 
• Functionally “closing the immunological door” 

This concept is consistently effective only within a tissue-level positioning strategy. 

3. Bone Can Taper Naturally 

Zirconia does not exhibit ductility at room temperature. Unlike titanium, it does not flex when under load.
As a result, the bone can taper naturally around zirconia implants without mechanical stress-induced resorption. 

The clinical implications may include:

• Potentially reduced need for augmentation procedures 
• Support for preservation of papilla height 
• Prevention of unnecessary smoothing of sharp ridges 

Again, proper tissue-level placement is essential to achieve this biological advantage. 

Our Clinical Conclusion: Consistent Tissue-Level Positioning 

Based on biological, mechanical, and clinical considerations, we made a deliberate decision. 

All implants were consistently positioned as tissue-level implants. 

This decision is not marketing-driven. It is based on:

• More than 20 years of experience with ceramic implants 
• Tens of thousands of placed implants 
• Daily clinical application at the SWISS BIOHEALTH CLINIC 
• Continuous product development informed by real-world practice.

Engineering for Biological Stability 

Dynamic Thread® – Apical Primary Stability

The apical portion of our implants features the self-cutting Dynamic Thread® design.

• Up to 2.5× thread depth
• Low thread pitch (7°) 
• Bone condensation in Class III and IV bone 
• Creation of healing chambers in dense bone 
• Insertion torque: 35 Ncm
  

The result aimed at achieving high primary stability and controlled load distribution, based on design principles. 

Cervical Micro-Thread 

In the region of highest mechanical stress, a 0.04 mm micro thread: 

• Adapts to cortical bone 
• Avoids harmful compression 
• Increases core diameter 
• Increases implant surface area in crestal bone and distributes forces reducing the risk of implant fracture

Tapered Implant Design Instead of Cylindrical Geometry

Ceramics do not dissipate iatrogenic heat. Therefore, we intentionally avoided cylindrical implant designs and aggressive cutting flutes. 

Our tapered implants:

• “Drop in” more than 70% in Class I bone 
• Minimize friction 
• Prevent overheating 
• Create healing chambers 
• May support faster initial bone healing compared to traditional designs

Biology before mechanics. 

Two-Piece — Yet Still Tissue-Level 

Even our two-piece system (SDS2.2) remains true to the tissue-level principle.

• The implant-abutment interface is not located in bone 
• The connection is positioned within the lower collar region 
• After cementation of the post into the implant, it functions as a prosthetic platform just as a one-piece system 
• No micro movements or other prosthetic components (=> no risk of screw-loosening)

This approach offers prosthetic flexibility while respecting biology. 

Conclusion: Tissue Level Is Not a Design — It Is a Biological Concept 

The comparison between tissue- and bone-level implants demonstrated the following: 

Bone level is a historically titanium-driven concept. 

Tissue-level — when properly implemented — is a biologically oriented approach that may:

• Support maintenance of crestal bone 
• Contribute to soft tissue stability 
• Help preserve papilla height
• Promote overall peri-implant health
• Potentially provide favorable esthetic outcomes

With zirconia as the material of choice⁵^-⁶, titanium implants positioned at bone level are no longer necessary⁷.

We do not consider implant dentistry in metallic terms; 
we think biologically. 

Therefore, our implants are consistently tissue-level.



FAQ – Soft Tissue Level vs. Bone Level Implants

References:

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2. Al Qahtani WMS, Schille C, Spintzyk S, Al Qahtani MSA, Engel E, Geis-Gerstorfer J, et al. Effect of surface modification of zirconia on cell adhesion, metabolic activity and proliferation of human osteoblasts. Biomed Tech (Berl). 2017 Feb 1;62(1):75–87.

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4. Thoma DS, Ioannidis A, Cathomen E, Hämmerle CHF, Hüsler J, Jung RE. Discoloration of the Peri-implant Mucosa Caused by Zirconia and Titanium Implants. Int J Periodontics Restorative Dent. 2016;36(1):39–45.

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6. Romanos GE, Fischer GA, Rahman ZT, Delgado-Ruiz R. Spectrometric Analysis of the Wear from Metallic and Ceramic Dental Implants following Insertion: An In Vitro Study. Materials (Basel). 2022 Feb 4;15(3):1200.

7. Kim S, Jung U, Cho K, Lee J. Retrospective radiographic observational study of 1692 Straumann tissue-level dental implants over 10 years: I. Implant survival and loss pattern. Clin Implant Dent Related Res 2018;20(5):860–866. doi:10.1111/cid.12659.