Abstract
Dental implants placed using a two-stage surgical protocol remain covered beneath the mucosa during osseointegration. A second surgical procedure, known as Stage II implant uncovering or second-stage implant surgery, is then performed to expose the implant, remove the cover screw and place a healing abutment.
Conventional methods include scalpel incisions, limited flaps and circular tissue punches. These remain established techniques but may cause bleeding, remove useful keratinized tissue or provide limited control over the final shape of the access opening.
Ceramic soft tissue trimming burs offer an alternative for selected implant sites. The MR.Bur ST-1, ST-2, ST-3 and Soft-T feature different diameters, working lengths and profiles for controlled tissue access, enlargement and refinement. This Clinical Pearl explains their design and potential application during implant uncovering. The burs should be regarded as case-selective instruments rather than universal replacements for scalpel, punch, flap or laser techniques.
Introduction
During a two-stage implant protocol, the implant and cover screw are submerged beneath the mucosa while osseointegration occurs. Once healing has been confirmed, the implant is uncovered and a healing abutment is placed to prepare the surrounding tissue for prosthetic restoration.
Although implant uncovering is usually a minor procedure, it must preserve sufficient peri-implant soft tissue, particularly the facial tissue and keratinized mucosa. Excessive or incorrectly positioned tissue removal may affect tissue adaptation around the healing abutment.
A crestal incision or limited flap allows the tissue to be preserved and repositioned but may produce bleeding and require suturing. A circular tissue punch creates rapid access but removes a predetermined collar of tissue. It may therefore be unsuitable when the implant is not centred beneath the ridge or when tissue augmentation is required.
A ceramic surgical bur allows the clinician to remove the overlying mucosa gradually. Instead of producing a fixed circular opening, the tissue can be trimmed incrementally until adequate access to the cover screw is obtained.
A pilot randomized controlled trial involving ten submerged single implants compared a ceramic surgical bur with a circular scalpel punch. The study found comparable clinical results and no thermal damage in the examined tissue specimens. However, only five implants were treated with the ceramic bur, so larger studies remain necessary.
Materials and Methods: Instrument Design
The MR.Bur Soft Tissue Trimmer range consists of FG ceramic instruments with different working profiles. They are not intended to be used as a compulsory four-bur sequence. The instrument is selected according to tissue thickness, access and the amount of trimming required.
MR.Bur ST-1
The ST-1 has a diameter of 1.9 mm, a working length of 4.5 mm and a total length of 23.5 mm.
Its short and relatively broad working section may provide controlled contact during initial exposure. It can also be used to enlarge a small opening after the cover-screw position has been confirmed.
MR.Bur ST-2
The ST-2 has a diameter of 1.6 mm, a working length of 9.5 mm and a total length of 25.0 mm.
Its long, tapered profile may improve access where adjacent teeth or the handpiece head restrict the operating angle. It is more suitable for lateral tissue trimming around an established opening than for searching deeply for an uncertain implant.
MR.Bur ST-3
The ST-3 has a diameter of 1.6 mm, a working length of 5.2 mm and a total length of 22.0 mm.
Its narrow and shorter profile may support conservative initial access, removal of small tissue tags and final refinement around the healing-abutment pathway.
MR.Bur Soft-T
The supplied product information shows the Soft-T with a diameter of 2.5 mm, an apparent working length of 7.0 mm and a total length of 25.0 mm.
Its broader conical profile may be useful when thicker superficial tissue must be contoured or when the initial access requires controlled enlargement. The 7.0 mm measurement should be confirmed as the working length before the specification is published because the supplied chart labels both measurements as “total length.”
Procedural Technique
Implant Assessment
Before uncovering, implant osseointegration, position and angulation should be confirmed. The clinician should assess the thickness of the mucosa, width of keratinized tissue and expected healing-abutment dimensions.
Ceramic bur-assisted uncovering is most suitable when the implant position is accurately known, sufficient keratinized tissue is present and no flap repositioning or tissue grafting is required.
A conventional flap may be preferable when the implant is facially or lingually displaced, soft-tissue augmentation is planned or the underlying bone must be inspected.
Localisation of the Cover Screw
The centre of the cover screw is identified using the surgical record, clinical assessment and appropriate imaging or guidance.
A ceramic bur should not be used blindly to search for the implant. Incorrect localisation may sacrifice valuable facial or lingual tissue and increase the possibility of contacting bone or implant components.
Initial Tissue Access
For a small, conservative opening, the ST-3 may be selected because of its narrow and relatively short working profile.
The ST-1 may be preferred where a slightly broader, short instrument provides better control. The bur is brought into light contact with the tissue using short, controlled movements.
The aim is to remove the superficial mucosa gradually until the cover-screw position is confirmed. Prolonged stationary pressure and forceful vertical advancement should be avoided.
Enlargement of the Opening
Once the opening is correctly centred, the ST-1 may be used to widen the access sufficiently for direct visualisation and engagement of the implant driver.
Where thicker tissue requires broader superficial reduction, the Soft-T may be considered. Tissue should only be removed until the cover screw can be accessed and the selected healing abutment can be placed.
A large circular opening is not always necessary. Excessive tissue removal may reduce the amount of mucosa available to adapt around the healing abutment.
Restricted or Angled Access
Where adjacent teeth or posterior anatomy restrict access, the ST-2 may be used along the lateral margin of an established opening.
Its extended taper allows tissue to be approached from an angle using a controlled sweeping movement. The longer working section provides reach, but it should not be interpreted as an indication for deeper penetration.
Final Refinement
Once the cover screw becomes visible, small residual tissue tags may be removed with the ST-3.
The ceramic bur should not be rotated against the cover screw, implant connection or implant platform. After adequate exposure, the bur is removed and the cover screw is disengaged using the compatible implant-system driver.
A healing abutment of appropriate height and diameter is then installed. Where a small soft-tissue remnant prevents complete seating, the ST-3 may provide localised refinement. The Soft-T may be used only when broader superficial contouring is genuinely required.
A simple procedure may therefore require only:
ST-1 → cover-screw removal → healing-abutment placement
A narrow-access procedure may involve:
ST-3 → ST-2 for lateral refinement → cover-screw removal
The clinician should not use every bur unless the tissue anatomy requires it.
Discussion
The different MR.Bur profiles allow instrument selection according to the clinical objective. The ST-1 provides a compact working section for initial exposure and controlled enlargement. The ST-2 offers extended lateral access. The ST-3supports focused access and marginal refinement, while the broader Soft-T may assist with thicker superficial tissue.
Compared with a tissue punch, a ceramic bur allows the opening to be created progressively rather than removing a fixed collar of tissue. However, both methods may sacrifice keratinized tissue if the implant position is incorrectly identified.
Compared with a scalpel, the ceramic bur removes tissue directly without requiring a linear incision. A scalpel or flap remains preferable when tissue must be preserved, repositioned or augmented.
Ceramic burs are sometimes described as producing effective hemostasis through frictional heat. However, the implant-uncovering pilot study found no histological evidence of heat-induced coagulation. The technique should therefore not be described as completely bloodless or incapable of producing thermal injury.
The study used another manufacturer’s ceramic bur at specified settings. Those settings should not automatically be transferred to the MR.Bur range. Speed, cooling, pressure, sterilisation and reuse must follow the current MR.Bur instructions for use.
Current evidence remains preliminary. The pilot trial involved only ten implants and detected no significant differences in temperature changes or postoperative pain between the ceramic bur and circular punch groups. These results support further clinical investigation but do not demonstrate that ceramic burs are superior to established techniques.
Conclusion
The MR.Bur ST-1, ST-2, ST-3 and Soft-T ceramic soft tissue trimming burs provide different working profiles that may support selected Stage II implant-uncovering procedures.
The ST-1 may assist with initial exposure and enlargement, the ST-2 with restricted lateral access, the ST-3 with focused trimming and the Soft-T with broader superficial contouring.
These instruments are alternative options rather than mandatory sequential steps. Successful use depends on accurate implant localisation, conservative tissue removal and recognition of cases requiring a scalpel, flap, tissue punch, laser or soft-tissue augmentation.
