2-Drill Protocol

The 2-Drill Implant Osteotomy Protocol

Crown Down's 2-drill protocol prepares the implant osteotomy in two steps with solid tungsten carbide drills.

Dr. Zvi Fudim, DDSBy Dr. Zvi Fudim, DDSClinically reviewed June 20263 min read

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.

Crown Down 2-drill osteotomy demonstration: cortical pass followed by final pass.
1

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.

2

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.

Osteotomy site after conventional drilling, showing rough walls and bone debris

Before

Conventional drilling

Osteotomy site after Crown Down 2-drill protocol, showing clean walls and preserved bone vitality

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?

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
Drill #1 prepares the cortical bone; drill #2 completes the osteotomy at the planned diameter. Source: Crown Down ANNEX 1.

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.

Crown Down drill depth marking code with letter markers a, B, b, c, and d corresponding to 6 mm, 8 mm, 10 mm, 12 mm, 13 mm, and 16 mm working depths in bone.
Letter code reads working depth as the drill engages bone. During drilling you can also collect autogenous bone chips for grafting. Source: Crown Down Annex 1.

Frequently asked questions

Quick answers to questions clinicians ask most about this topic.

Ready to upgrade your implant workflow?

The Crown Down kit replaces your entire drill sequence with 2 solid tungsten carbide drills, guided and freehand compatible, with universal implant-system support.

Free 15-min consultation • Guided and freehand compatible • All implant systems