Module 2 — Placement Technique
The slide deck for this module is in the members’ board.
Learning objectives
- Defend self-drilling with a hand driver as the general-practice standard
- Place at ~30° into the safe zone — and explain why perpendicular flirts with roots
- Read the soft tissue before choosing the insertion point
Self-drilling vs self-tapping
A TAD is an endosseous implant retained mechanically — not by osseointegration. That is what makes it temporary, immediately loadable, and removable. Two insertion philosophies exist:
- Self-drilling — the clinic standard. Anesthesia, then the screw cuts its own path under a manual driver. No pilot hole. The safety is in your fingers: hand insertion gives tactile feedback — abnormal resistance warns of root proximity before damage is done.
- Self-tapping requires a pilot drill at high speed first: an extra step, a deeper-than-intended-hole risk, and no tactile warning until it is too late. It is also more punishing to tissue than the manual screw. Its honest place: dense extra-radicular bone — zygoma, mandibular buccal shelf — where maximum purchase matters.
Verdict for general practice: self-drilling — root and nerve safety, plus stability.
The 30° safe-zone law
Perpendicular (90°) insertion is acceptable if you can direct it perfectly — but roots taper toward the apex, and at mid-root height a perpendicular path flirts with perforation.
- Standard: ~30° apical angulation — inclined from above in the maxilla, from below in the mandible.
- Enter at the middle third, aim toward the apical third — the tapering roots open a wider safe zone apically.
- The screw seats in inter-radicular bone between (classically) the second premolar and first molar; anchored toward the teeth it remains an inter-radicular screw even on the palate.
Read the soft tissue first
Do not chase the highest vestibular point. Frena and mobile mucosa there pull with every smile — tension loosens screws. Place within attached gingiva. Before choosing the spot: reflect the lip with your mirror, have the patient open, close, smile, and read where the attachments move. Retraction and a gauze press keep the field readable during insertion.
Extra-radicular sites (the advanced chapter)
- Infrazygomatic crest: palpable above the first/second molar — learn it with your finger before any screw; a depression marks the site.
- Mandibular buccal shelf: the screw goes essentially straight down lateral to the roots — nothing to perforate, which is exactly why the screw’s build quality (credible brand) carries the trust.
- These sites pair with 2.0 mm diameter, long-neck designs — and with self-tapping where bone density demands it.