1. Anterior Middle Superior Alveolar *
(AMSA)
* Friedman MJ, Hochman MN. The AMSA Injection, A New Concept for Local Anesthesia of Maxillary Teeth
Using a Computer-controlled Injection System. Quint. Int’l. 1998: 297-303

2. AMSA Block Injection
• Single Site, Palatal Approach
• 5 Teeth and Tissue Anesthetized
• Duration Approx.
60-90 minutes
• Dose Approx.
¾-1 Cartridge (2% Drugs)
½ Cartridge (4% Drugs)
– Rx: Articaine 1:200,000
The Textbook of Local Anesthesia (Fifth Edition), Malamed S. DDS

3. New Approach
Palatal Instead of Buccal

4. AMSA Landmarks
• Midway Between Free
Gingival Margin and
Mid-palatine Suture
• Bisects Premolars

5. Computer-Controlled
INJECTION
DYNAMICS

6. Components of an Injection
• Puncture
• Penetration
• Delivery

7. Puncture
•Topical
•Pre-Puncture

8. Pre-Puncture

9. Puncture

10. Penetration

11. Anesthetic Pathway

12. Penetration
• Anesthetic Pathway
• Slight Rotation
• ControlFlo
• Paced Advancement
(2/4 Rule)

13. Delivery

14. Delivery of Anesthetic
• ControlFlo
– Penetration
– Palatals, Intraligamentary Injections
– Tissues of Resistance
• RapidFlo
– Tissues of Least Resistance
– Infiltrations, Inferior Alveolar Blocks, etc.

15. AMSA Scope of Anesthesia

16. AMSA Benefits
The anterior teeth are anesthetized in
both views

17. STA-Intraligamentary Injection

18. Periodontal Ligament Injections
Traditional Syringe
Ligmaject

19. STA Dynamic Pressure Sensing
(DPS)
• Informs the Dentist of Correct Injection Site (PDL Space)
with Ascending Lights and Sounds.
• Informs the Dentist if the Needle has Left the Correct Site.
• Informs the Dentist if the Needle has been Blocked.
• All Feedback Information in Real Time.

20. STA Intraligamentary vs.
Syringe PDL
Limited
Feedback
Total
Feedback

21. STA-Intraligamentary Injection
• Site-specific Injection
• Primary Injection
• Dosage of:
– ½ Cartridge per Root (2% Lidocaine)
– ¼ Cartridge per Root (4% Articaine)
– Recommended: Articaine 1:200,000
• Delivery Time 2-4 minutes
• Duration of Approx. 45-60 minutes
• Safe, Comfortable, Successful Injection

22. STA-Intraligamentary Injection
Injection Sites
• Maxillary Teeth
– Distal-buccal & Mesial-buccal Line Angles
• Mandibular Teeth
– Distal-lingual & Mesial-lingual Line Angles
– Buccal bifurcation on some lower molars
• Always Start on Distal then Mesial

23. Shorten Wand Length
• Break Wand
Handpiece shorter
for easier access
• Bend Needle about
10-15o towards the
bevel, if necessary

24. STA-Intraligamentary Injection
Technique
• Verify the STA mode is
ON
• Place the needle
passively in the gingival
sulcus at about a 45o
orientation to the
vertical
• Keep the bevel towards
the tooth

25. STA-Intraligamentary Injection
Technique
• Maintain the needle’s 45o
orientation
• As the flow of anesthetic is
started and Cruise Control is
engaged, slowly and gently
move the needle apically

26. STA-Intraligamentary Injection
Technique
• Continue to slowly
move the needle
apically until resistance
is felt at the top of the
PDL space
• Hold the needle in place
with minimal pressure
• Wait for the STA sound
and light indicators to
begin

27. STA-Intraligamentary Injection
Technique
INCORRECT TECHNIQUE
• Wrong Needle Orientation
(Too Vertical, not 45o)
• Needle too deep into the
PDL space
• Excessive Pressure on
Needle

28. Tissue Effects
• Circumferential
Blanching “suggests”
Adequate Anesthesia
• Blanching Occurs with
Anesthetics Containing
Vasoconstrictors

29. Dr. Marco Ferrari Clinical Study
International Dentistry, South Africa 2009
STA-Intraligamentary Injection
vs. Syringe & Ligmaject PDL
• STA - Faster Onset of Anesthesia
• STA – Less Discomfort During the
Injection
• STA – More Effective Anesthesia
• STA – Longer Duration
• STA – Less Post-op Discomfort
Conclusion: “STA produces more
predictable, reliable, and
comfortable anesthesia than the
dental syringe or Ligmaject”.

30. STA-Intraligamentary Injection
• Simple to Administer
• No Tissue Damage or Bone
Resorption
• Comfortable for Patients
• Minimal Collateral Anesthesia
• No Intravascular or Trismus Risk
• Almost Immediate Onset of
Anesthesia
• Increased Productivity