TOOTH ANAESTHESIA

1

SYSTEM Q&A - PART 1

WITH DR. EUGENE CASAGRANDE

WIT H DR EUGE N E C ASAGRAN D E

1. Do we need to use Topical anaesthetics with the STA system?

It depends on the injection. Topical anaesthetic works well on mucosal tissue, if used properly When delivering an infiltration or a mandibular nerve block, I would use a topical anaesthetic by placing the topical on the mucosal tissue at the site of the needle puncture and then waiting for at least a minute before piercing the tissue. However, topical anaesthetic does not work well on the dense tissue of the palate, so the STA pre-puncture technique is useful for piercing the palatal tissue comfortably when performing the AMSA and P-ASA injections. Topical anaesthetic is not needed for single tooth injection or crestal technique.

2. Can you bend the tip when injecting?

The needle can be bent from the hub just slightly (5-10 degrees) towards the needle bevel when delivering a single tooth injection on mandibular teeth. This is useful to achieve better access and to determine where the bevel is, since the needle bevel should be placed towards the tooth during this injection. This is the only situation that I would recommend bending the needle.

3. How do we change the cartridge for multi-cartridge use?

After dispensing the first cartridge during a mandibular block injection, the needle can be held at the injection site; the dental assistant takes out the spent cartridge from the cartridge holder and loads a new cartridge into the cartridge holder; before placing the next cartridge onto the top of the STA system, the Multicartridge Button should be activated. This will cause the instrument to omit the purge cycle, which forces air out of the micro-tubing and fills it with anaesthetic and will allow the next cartridge to be administered without removing the needle from the injection site

4. How deep is the needle inserted?

This depends on the injection. The proper and appropriate needle length should always be used; and in any injection the needle should never be inserted deep enough to reach the hub of the needle. For the traditional infiltration and mandibular block injections the STA needle is inserted into the tissue as deep as with the dental syringe – to the injection site. Generally, for the STA injections, the needle should be inserted deep enough to reach the injection site. For the AMSA, the needle is inserted through the palatal tissue until the palatal bone is reached. For the P-ASA, the needle is inserted through the palatal tissue and into the nasal-palatine canal no deeper than approximately one half of the 30 ga. ½ inch needle. For the single tooth injection, the needle is inserted into the tooth’s sulcus until resistance is met, which should be the bottom of the sulcus and the top of the periodontal ligament space. For the crestal injection on an edentulous area, the needle is inserted through the crestal gingival tissue until the bone is met.

5. What is the Bi-rotational technique & when do we need to use it?

When performing a mandibular block (IA) injection with a dental syringe, all needles will deflect away from the needle bevel as the needle penetrates the tissue to the injection site due the use of mono-bevel needles. This has been shown to be 5-7 mm and is why it takes so long to achieve successful anaesthesia with this injection. Using the STA system handpiece and rotating it 180 degrees as the needle penetrates the tissue to the injection site, needle deflection is cancelled, and the needle goes straight to the injection site. Using the STA for a mandibular block injection has proven to be more successful; produces faster onset of anaesthesia and is less painful in children.

6. Any tips for new users?

Before initial use, the STA system requires operator and staff training on Setup, Operation, Features, Maintenance, and injection techniques. This training is provided by Henry Schein and is useful so that the operator and staff are knowledgeable and confident before the first injection on a patient. When performing the STA injections, the best advice is to always use a 30 gauge Short (1/2“needle), always use the STA Mode of one drop every two seconds; and never use excessive pressure on the needle. More useful information, including important injection videos, is available on the manufacturer’s website: milestonescientific.com/dental-solutions & Henry Schein Dental Education Hub and should be reviewed: dentaleducationhub.com.au/?s=Wand+STA

Author

Dr. Eugene R. Casagrande has practiced Cosmetic and Restorative Dentistry for over 30 years in Los Angeles. As the Director of Inter national & Professional Relations for Milestone Scientific for over 23 years, he has published multiple articles and has lectured both nationally and inter nationally at over 100 dental schools and in over 50 countries on Computer-Controlled Local Anaesthesia