tips and tricks

 Often times when performing a cavity preparation, there will be sensitivity elsewhere in the mouth either due to exposed dentine or caries. This can make the procedure more difficult in patients with rampant caries, recession or generalised wear. Pain relief is important at this time so there are several strategies I use in these situations: 1. Use rubber dam, This will remove the problem entirely, sometimes if the situation is nfavourable, rubber dam may not be possible to use for the entire restoration, but at least short term use of the dam can help get the bulk of the prep out of the way comfortably. 2. Give local anaesthetic in the other areas. You can be hesitant to do this because that isn't the area you are working on but in the end, we give anaesthetic to block nerve conduction percieved as pain so the patient can get through the appointment comfortably. Therefore, if the patient is agreeable, local anaesthetic at the other painful sites can be very useful to achieve this...

One thing I am never sure of during an intraligamentary injection is "is the needle tip in the PDL space or in the tissues?"Always use a small gauge needle even if you have a large gauge needle out for a block. A larger gauge needle will be too chunky to predictably fit into the PDL space. The angle of the needle is important and should be pointed towards the tooth surface. If it is inserted quite parallel o the tooth it will tend to sit in the gingival tissues and you will feel back pressure but will only be injecting into tissues with nothing reaching the periapical tissues. You may notice quite profound blaching in the area if you're inecting mainly into the tissues. In a thin biotype, it is quite easy for the needle to deflect away from the tooth and pierce the tissues back into the oral cavity. The best indication of a good needle placement is when you pull back, the needle tip is stuck in the PDL space and it is difficulty to remove. A patient with significant apica...

 I was helping out one of the younger colleagues in the extraction department the other day with a very difficult case. This was one of the times I would say that the tooth was genuinely difficult to anaesthetise due to a hot pulp. In the past I had quite a few cases where I failed to achieve anaesthesia and blamed hot pulps only to realise it was probably my own technique that was inadequate and the excuse was just too convenient. This tooth was a heavily carious upper premolar with a significant curve on the root which bordered the maxillary sinus. The curve was to the mesial which was strange and it seemed to follow the outline of the sinus so we can assume that the expansion of the sinus at the time of tooth formation led the tooth root to curve to the mesial.  Challenges involved in the anaesthesia of this patient were: -Very dense bone: which I noted as we were elevating the tooth. Elevation and forcep movements hardly produced any movement of the tooth which is common w...

Local anaesthetic is in general a safe drug which is fortunate because as dentists we use this every day. More than any technique or surgical skill it is the single most effective tool to improve success rates in our procedures. Can you imagine how hard any simple restorative or surgical work would be without the assistance of local anaesthetic? As it is used locally as opposed to systemically, the body can tolerate a fair amount of solution before we are concerned about toxicity. For most dental procedures toxicity isn't a concern however for complex and lengthy procedures as well as in children and the elderly it must be a consideration. In procedures such as full clearances or lengthy procedures such as rehabilitations you must use a safe local anaesthetic and keep track of the amount used. Adrenaline containing local anaesthetics cause localised vasoconstriction which reduces the rate at which local anaesthetic solution is washed into the system. Therefore a lower concentra...

From Therapeutic guidelines Oral and Dental 2012 Anaesthesia: A state of controlled, temporary loss of sensation. It may involve analgesia, paralysis and amnesia or unconsciousness. Analgesia: Inability to feel pain Local anaesthetics in dentistry are used locally or regionally to produce loss of sensation essentially blocking somatic and noniceptive stimulation as well as motor nerve conduction. Their action is mainly blocking of sodium channels along neurons that essentially block the formation of action potentials. The progression of nerve function blockage relates to nerve diameter, myelination and conduction velocity. First, autonomic activity is blocked then nociception, other sensory functions then motor activity. In dental applications, Soft tissue innervation tends to be located on the outside of the nerve trunk and pulpal innervation towards the centre. Therefore soft tissue anaesthesia will precede pulpal anaesthesia and pulpal anaesthesia will wear off before soft tiss...

The "classical" technique of performing an IAN block involves inserting the needle just anterior to the pterygomandibular raphe at a level in the middle of the occlusal plane at the height of the deepest concavity of the anterior border of the ramus from an angle aiming from the contralateral premolar region. Multiple factors can hinder ideal placement of the needle including trismus, lack of hard and soft tissue landmarks, patient anxiety and a large tongue. A large tongue tends to spread out over the occlusal surfaces of the lower teeth and move laterally and may actually block the site of injection in severe cases.it may also rise upwards especially if the patient is anticipating pain and hinder the correct angulation of the barrel of the syringe lying across the arch. Rather than instruct the patient to move their tongue to the side which almost always causes them to spasm their tongue in random directions, attempt to have the patient's head in different positio...

A few thoughts about the technique behind mental nerve blocks: - The path of the IDN through the mandible starts at the mandibular foramen. This is the ideal site for the deposition of anaesthetic for an IDB. as the nerve approaches from superiorly and posteriorly a higher chance of success is gained from injection most posterior and superior. However, too posterior may result in affecting the facial nerve which lies just posterior to the ramus of the mandible. Too far anteriorly will stop the spread on anaesthesia due to a ligamentous attachment to the lingula (sphenomandibular ligament) - Upon entering the mandible, the IDB tracks anterior through the bones near the apices of the lower teeth. At the molar region (if I recall correctly), it sits more to the lingual cortical plate and it shifts to a more buccal position at around the premolar region. This and the denser quality of the bone is why infiltrations have a poorer success rate on lower posterior teeth. At the site of the me...

Products of inflammation lower the surrounding tissue pH (e.g., purulent exudates have a pH of 5.5-5.6). At this more acidic pH, the numbers of base molecules necessary for passage of the anesthetic into the nerve membrane may be significantly reduced. Inflammatory exudates may also enhance nerve conduction action potentials, making blockage of sensory nerve impulses more difficult. In addition, blood vessels in the area of inflammation may be dilated, leading to a more rapid uptake of the anesthetic agent from the area of injection. These changes can lead to delays in onsets of anesthesia, inadequate depths of anesthesia, and the potential for local anesthetic blood levels to be elevated.  Needle tract  infection  is a potential complication of injection into  infected  tissues. Although penetration into  infected  tissues can be avoided by using more distant regional nerve blocks, whenever there is a possibility of a needle having passed through...

Today I had to extract lower 3-3 for the insertion of a full lower immediate denture. I was hesitant to give bilateral IDBs and asking around it seemed as though the other dentists would be as well. I got around it by giving bilateral mental blocks and lingual infiltrations. There were no premolars for intraoral landmarks so I palpated extraorally then intraorally to find the mental foramen. I retracted the soft tissues with my finger to have an intraoral reference to penetrate the mucosa. Lingual infiltrations I placed around the lateral incisor area and it seemed to be sufficient to anaesthetise one tooth either side. The OPG also helped in approximating the position distal to the canines.

Once clear vision and a stable fulcrum have been established, penetrate the mucosa to a depth of 1-2 mm (approximately the length of the bevel) with the bevel oriented  toward bone . A few drops of solution are usually deposited as needles are advanced because even gentle contact with the thumb on the front inner surface of the thumb ring will cause a few drops of anesthetic to be deposited ahead of the needle. Note that this does not require visibly advancing the stopper and no separate action is required other than to proceed slowly. The total volume administered in this manner should be less than 0.2 mL (the volume displaced by 1 stopper length). --- Despite performing this step (aspiration) correctly, it is still possible to have false negative aspirations  at times. This can occur when a bevel is in contact with a vessel wall. During an aspiration test, negative pressure can retract the vessel wall into the lumen of the needle blocking the flow of blood through the ne...

 Modifications to Local Anesthesia for Common Medical Conditions Condition Local Anesthetic Considerations Vasoconstrictor Considerations Modifications Diabetes None of Significance Epinephrine opposes the action of insulin Minute amounts used in dentistry do not raise blood levels significantly Use epinephrine with caution  when there is significant cardiovascular disease and/or uncontrolled diabetes. Glaucoma None of Significance Vasoconstrictors cause increased ocular pressure Avoid  vasoconstrictors Hypertension None of Significance Vasoconstrictors can increase the risk of hypertensive episodes however the  lack  of profound anesthesia can increase levels  of endogenous epinephrine Controversial topic Clinical  judgment  and medical  consult  advised Note : Uncontrolled hypertensives either should not be treated or treated with  caution , depending upon severity See  Table 10-1 ...