PDL - Intraligamentery Anesthesia  

Injections training by  

Stanley F. Malamed, D.D.S.       Video part 1 - Introduction       partl 2  - techniqs error 






 

Modified STA-INTRALIGAMENTARY INJECTION

The STA System provides Dynamic Pressure Sensing™ technology that is capable of identifying specific tissues during the dental injection.  The STA mode allows the practitioner to accurately identify the periodontal ligament tissue.  It also enables the clinician to maintain the correct needle position within the periodontal ligament when performing the newly described STA Intraligamentary Injection. Developed by Dr. Mark Hochman, the STA Intraligamentary Injection represents a new concept in local dental anesthesia techniques.

 

The STA System is the only anesthesia system that provides clinicians with the 3 critical elements of information when performing a STA Intraligamentary Injection:

 

1.    It guides the clinician to position the needle tip to the periodontal ligament.

2.    It provides ongoing feedback that the needle has not moved during the procedure.

3.    It alerts the dentist if there is a blockage or any leaks in the system.

 

Performing the STA INTRALIGAMENTARY INJECTION

 

1.         Turn the STA drive unit to “On”.  The system will default to the STA mode.

2.         Load and attach the STA bonded handpiece with the 30 gauge ½ inch needle and the appropriate anesthetic.  The unit will automatically purge the air from the system.  Rest the handpiece in the cap holder.

3.         While holding the STA handpiece in a pen-like grasp, place the needle into the gingival sulcus of the tooth to be anesthetized. Simultaneously, activate the ControlFlo™ rate by depressing the foot control.  It is important to gently and slowly advance the needle within the sulcus, as if it was a periodontal probe.  It is highly recommended that the clinician use a finger rest to control and stabilize the needle movements.

4.         The STA System provides a continuous audible and visual feedback to guide the needle tip to the periodontal ligament.   As the foot control is depressed, the device says “sensing”  The user will then hear the word “Cruise” at which time the cruise control function can be operated by removing one’s foot from the pedal.

5.         In the STA mode, the DPS technology provides real time pressure feedback via:

a.    The visual Pressure Sensing Scale (Gauge) is comprised of a series of orange, yellow and green LED lights.  The orange LED’s indicate minimal pressure, the yellow LED indicate mild pressure and the green LED’s indicate moderate pressures that are indicative of the periodontal ligament tissue.

b.    The auditory Pressure Sensing Scale is composed of a series of triple ascending tones “beep, beep, beep”   Increasing pressure is indicated by the triple ascending sequence.  When the periodontal ligament is identified, the user will hear the letters “PDL” spoken three times, followed by a series of extended tones “beeeep, beeeep” indicating correct needle positioning.

 

 

 

 

 

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Fig. 13

 

 

The continuous DPST technology provides the user with important on-going information that the needle has not moved from the optimal location during the entire injection process.  The DPST feedback will also alert the operator to the proper hand pressure to the handpiece.  Excessive pressure can result in the “blockage” of flow of anesthetic solution.  This will be detected and result in an “over pressure” condition. 

 

The “Over-pressure” condition, i.e. when pressures exceed 450 PSI, the over pressure alarm will be sounded. The user will need to release the foot control or stop cruise control.  The user will then need to restart the injection moving the needle to a new location.  The unit’s maximum generated pressure is 450 psi ± 10%.  The maximum infusion pressure will not exceed 500 PSI.

 

Dosage volume

 

The STA system allows for a virtually unlimited amount of anesthetic to be deposited.  The operator should use his/her own judgment as the anesthetic drug selection and the volumes used. The following are suggestions and clinicians are encouraged to reference the appropriate drug manufacturers, current dental literature and textbooks for recommended dosages and drug recommendations.

a.    A drug volume of 0.9 ml is recommended for single rooted teeth.

b.    A drug volume of 1.8 ml is recommended for multi-rooted teeth.

c.    The use of local anesthetics containing a vasoconstrictor concentration of 1:50,000 parts is not recommended for an Intraligamentary injection.

d.    When using local anesthetics concentrated at 4% (Articaine Hydrochloride 4% and Prilocaine Hydrochloride 4%), a drug volume of 0.4 ml is recommended for single rooted teeth and a drug volume of 0.9 ml is recommended for multi-rooted teeth.

 

 

 

Removal of the needle from the ligament should be performed mid-way during the aspiration cycle.   Since the injection is performed under pressure, if the needle is otherwise removed, the patient’s mouth will be sprayed with bitter tasting anesthesia.  Therefore, the operator is advised to remove the needle during aspiration, i.e. when the STA drive unit is retracting during aspiration.

 

Based on the auditory and visual pressure sensing feed-back, it is not unusual for the operator to have to reposition the needle several times before locating the proper position of the needle within the periodontal ligament.  Additionally, slight needle movements can result in rapid loss of pressure.  The user will need to withdraw and reposition the needle to establish an effective periodontal ligament location.