Live surgical case
Two drills.
Every osteotomy.
Cortical drill, final drill, place the implant. One instrument change per site. Watch the protocol on a real D1-bone case, filmed unedited.
Case detail
Lower-right premolars #45 & #47, D1 bone
A demanding density-class case where a 2-drill carbide protocol is expected to fail. Full unedited surgery below.
Protocol Walkthrough
How does the 2-drill implant osteotomy protocol work?
Drill #1, the cortical drill, prepares the cortical bone. Drill #2 completes the final osteotomy. Two passes per site, suitable for both guided surgery drill kits and freehand implant surgery.
Drill #1
Cortical Preparation
Drill #1 engages the cortical layer and establishes the osteotomy path. One step replaces the multiple pilot and intermediate drills used in conventional 5 to 8 step kits.
Drill #2
Final Osteotomy
Drill #2 completes the final osteotomy diameter for implant placement, indexed to the planned implant size from 3.2 to 6.0 mm.
Why Tungsten Carbide
What makes the 2-drill protocol possible?
Built-in thermal safety
Solid tungsten carbide conducts heat away from the osteotomy faster than steel. Up to 6x less heat in internal thermal testing under controlled conditions.
Guided & freehand
One kit covers both workflows: guided osteotomy preparation with 3D stoppers, and freehand surgery with tactile bone feedback.
No routine replacement
Solid carbide maintains its cutting geometry under normal clinical use. Routine drill replacement from progressive dulling is eliminated.
Clinical Proof
Heat testing & clinical imaging
Internal thermal testing and clinical imaging show predictable osteotomies with preserved bone vitality and clean, intact walls.
Live case
Crown Down drill mid-osteotomy in a real surgical case
Before
Conventional drilling
After
Crown Down method
In-vitro bovine rib testing shows minimal measurable cutting-edge wear after extended drilling cycles under controlled conditions.
Technique Clips
What does the 2-drill protocol look like in practice?
The Protocol
Three steps, two drills, zero memorized sequence.
Pick the cortical drill matched to your implant diameter, complete the osteotomy with the paired trabecular drill, and read working depth from the laser-marked letter code as you go.
- 1
Cortical preparation (Drill #1)
Engage the crestal cortical bone at low RPM with the cortical drill matched to your implant diameter. Solid tungsten carbide cuts efficiently and evacuates heat, so a single pass replaces two-to-three stainless-steel pilot drills.
- 2
Final osteotomy (Drill #2)
Complete the site to final depth with the slightly undersized final drill. Two passes total, no sequential steel drill line-up to memorize, no cool-down pause between passes.
- 3
Read depth, place the implant
Laser-marked letter code (a / B / b / c / d) shows working depth at 6, 8, 10, 12, and 16 mm as the drill engages bone. You can also collect autogenous bone chips on the same pass for grafting.
Drill Selection
Crown Down Drilling Chart
Two drills per site. Choose drill #1, the cortical drill, for crestal preparation and drill #2 to complete the osteotomy to final depth, indexed by the implant diameter you are placing. Both are Crown Down’s solid tungsten carbide dental implant drills, shipped on the surgical implant kit for freehand work or the guided implant drill kit for template-based cases.
The mechanical reason drill #1 is the larger of the two drills - not the smaller one, as in a conventional ascending sequence - is developed in the Wear-Proof Implant Drills clinical analysis. In short: solid tungsten carbide is brittle, so the smaller drill must never be the one facing full cortical resistance.
| Implant diameter (mm) | Drill #1 (cortical) | Drill #2 (final) |
|---|---|---|
| 3.2 / 3.3 / 3.5 | #35 | #20 |
| 3.75 / 3.8 / 4.0 | #40 | #30 |
| 4.2 / 4.3 / 4.5 | #45 | #35 |
| 4.75 / 4.8 / 5.0 | #50 | #40 |
| 5.2 / 5.5 / 6.0 | #60 | #45 |
Depth Marking
How do you read the depth markings on Crown Down drills?
Crown Down drills are laser-marked with a letter code (a / B / b / c / d) so you can read working depth at a glance during osteotomy preparation. The diagram below maps each marker to a clinical depth in bone.
Frequently asked questions
Quick answers to questions clinicians ask most about this topic.
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