Dental Syringe Lecture Notes PDF

DENTAL SYRINGE  THE ARMAMENTARIUM 4 PARTS: 1) The Syringe 2) The Needle 3) The Cartridge 4) Preparation  THE SYRINGE Standard of Care  aspirating dental syringes are the standard of care due to their ability to aspirate blood if the tip of the needle is located intrava...

DENTAL SYRINGE  THE ARMAMENTARIUM 4 PARTS: 1) The Syringe 2) The Needle 3) The Cartridge 4) Preparation  THE SYRINGE Standard of Care  aspirating dental syringes are the standard of care due to their ability to aspirate blood if the tip of the needle is located intravascularly PARTS OF DENTAL SYRINGE  SELF-ASPIRATING USES THE ELASTICITY OF THE RUBBER DIAPHRAGM IN THE ANESTHETIC CARTRIDGE TO OBTAIN THE REQUIRED NEGATIVE PRESSURE FOR ASPIRATION TESTING PERMITS FOR MULTIPLE ASPIRATIONS EASILY  ASPIRATING SYRINGE -the needle adaptor is sometimes inadvertently discarded along with the disposable needle -the harpoon is a sharp tip attached to the piston and is responsible for penetrating the thick silicone rubber stopper (bung) at the other end of the cartridge  - negative pressure is applied to the thumb ring by the administrator, if blood enters the glass local anesthetic cartridge (carpule) so the tip of the needle is inserted into the lumen of a blood vessel chrome-plated brass and stainless steel  PRESSURE SYRINGES -PDL (intraligamentary) injections  JET SYRINGES -needle-less injection -liquids forced through very small openings, called jets, at very high pressure can penetrate skin or intact mucous membrane -Syrijet is the most popular used today -Syrijet holds any 1.8 ml cartridge of local anesthetic  SAFETY SYRINGE -some brands come with an autoclavable plunger and disposable self-contained injection unit -all dental safety syringes are made to be single use items  2-DENTAL NEEDLS Needles The main components of the dental anesthetic needle include 1.the bevel. 2.Shank. 3.Hub. 4.syringe adaptor. 5.and cartridge penetration end. PARTS OF NEEDLE  THE NEEDLS DIVIDED DEPENDING ON 1- LENGTH Dental needles are available in three lengths: long, short, and ultrashort. The two most common lengths of needles used for intraoral injections with the traditional syringe are the "long" and the "short". The length of the needle can vary some by manufacturer, but usually, from hub to tip, a long needle is about 32 mm (1.5 inches) and the short is about 20 mm (1.0 inch) The long needle is required for mandibular blocks, because the depth of penetration ranges from 20-25 mm for an average adult (20-25 mm for the inferior alveolar and 25 mm for Gow-Gates mandibular block techniques). It is extremely important to avoid insertion to the hub, the weakest part of the needle.. At the hub, the needle can break more easily. If the needle does break, and if there is not at least 5 mm of it exposed, it would likely be lost in the tissues and very difficult to retrieve. The long needle is also recommended for the anterior superior alveolar (ASA)/infraorbital approach injection. A short needle is usually preferred for the posterior superior alveolar injection (PSA) to avoid overinsertion, for supraperiosteal injections, and also tissue infiltrations  NEEDLE GAUGE : The gauge of the needle represents the diameter of the lumen, the hollow tunnel within the needle. In dentistry, common gauges include: 25, 27, and 30 (the 30-gauge needle is no longer recommended)-the larger the number, the smaller and thinner the gauge. As mentioned above, patients are unable to distinguish between 25-, 27-, and 30-gauge needles. With the larger gauge (25 or 27) needles, because they are more rigid, there is resistance to needle breakage and less deflection as it advances through deeper tissues, which then results in greater accuracy for reaching the desired target.  The 25-gauge needle has been recommended for all injections, but it is strongly recommended for all injections with a high risk of positive aspiration and/or with a significant depth of penetration. The 27-gauge needle is restricted for other injections where depth of penetration and risk of positive aspiration are minimal. The 30-gauge needle is not recommended for supraperiosteal or block injections, but can be useful for localized infiltration (injecting the papillae, for example, to obtain hemostasis BEVEL CORRECT POSTION  The orientation of the bevel should be toward the bone during injections that are close to the periosteum. Doing so increases patient comfort and reduces trauma to the periosteum if bone is contacted. DENTAL CARTRIDGE (CARPULE): The dental cartridge is a glass cylinder containing the local anesthetic solution. It consists of: 1.Cylindrical glass tube. 2.Stopper located at the end of the cartridge that receives the hook of the aspirating syringe. 3.The aluminum cup is located at the opposite end of the cartridge from the stopper to hold the diaphragm in its position. 4.Diaphragm. Care and handling of the dental cartridge Glass dental cartridges should not be autoclaved.