The Effect of NSAID Premedication on the Success of Inferior Alveolar Nerve Block in Pulpitic Teeth Prior to Endodontics

Pain control at the outset of endodontic treatment is critical and makes both the patient and dentist confident and comfortable for the remainder of the treatment. Maxillary teeth are the easiest teeth to achieve profound anaesthesia and rarely test our anaesthetic skills. Mandibular teeth, especially mandibular molars with irreversible pulpitis, are an entirely different kettle of fish. It is these teeth which make us tear our hair out, puts us behind in our schedule, makes the patient question our skills, and gives endodontics a bad name.

The ability to achieve profound Inferior Alveolar Nerve block (IANB) anaesthesia, quickly, painlessly, and consistently not only reduces the stress level for patients and dentists but is a great practice builder. A variety of anaesthesia techniques, anaesthetic formulations, and analgesic premedications have been studied over the years.

Nerve action potentials occur through the process of depolarization and repolarization. A stimulus allows sodium ions to move into the interior of the nerve cell through openings in the nerve cell membranes known as sodium channels. This changes the electrical charge within the nerve cell from negative to positive (depolarization). Active pumping of the sodium ions out of the nerve cell restores the normal negative resting state electrical charge within the cell (repolarization). The process of depolarization and subsequent repolarization moves along the nerve cell from pain receptor to nerve cell body and eventually to the brain. Local anaesthetics reduce pain in dentistry by blocking the sodium channels and preventing depolarization. Profound anaesthesia completely blocks the pain stimulus from reaching the brain, allowing for comfortable endodontic treatment.

Pulpal inflammation produces a number of inflammatory mediators, with prostaglandins being one of the most well studied. Prostaglandins upregulate expression of sodium channels in nerve cells. The more inflammation that occurs, the more sodium channels are created, the easier nerve cells depolarize and the more effective the anaesthetic needs to be to achieve a profound block. It is this augmentation of sodium channels in inflamed teeth, i.e. irreversible pulpitis, that has stimulated a series of investigations into premedication with prostaglandin blocking NSAIDs.

Abbot et al, JOE 36:9, investigated the effect of premedication with NSAIDs on efficacy of IANB. 150 mandibular molar teeth with a diagnosis of irreversible pulpitis were chosen for this double blind study. The teeth were divided into three groups of 50. Each group received either placebo, 600mg ibuprofen, or 75mg indomethacin (most commonly used in arthritic conditions) in identical capsules to avoid bias. The premeds were given one hour prior to IANB. Each participant was asked to rate their response to cold stimulus on the visual analog scale (VAS) prior to premedication, one hour after premedication (which was the time of IANB with one carpule of lidocaine 1:80,000 epinephrine) and then 15 minutes following IANB during endodontic treatment.

Abbot et al found that the overall success rates for no or mild pain during endodontic treatment were 32% for placebo, 78% for ibuprophen, and 62% for indomethacin. Both medications significantly helped with pain reduction during endodontic treatment in pulpitic teeth following one carpule of lidocaine with epinephrine. Of interest is the placebo effect. Just the effect of giving the patient something that they assumed would help them with their pain made the patients feel less pain.

Attaining an efficacious and efficient IANB is crucial to making our patients comfortable and treatments go smoothly. This study indicates that extensive dentistry in the lower arch, including endodontics on pulpitic teeth, benefits from premedication with 600mg of ibuprophen, and that this greatly assists us in attaining our goal of pain-free dentistry. We have been using an ibuprophen premedication in all of our patients without contra-indications to NSAIDS for at least 10 years with good effect. Not only do we get reduced post-treatment pain, but we have indications that this causes our anaesthesia to work more effectively as well.

 

ABOUT DR. HOWARD BITTNER

Dr. Bittner was born and raised in the Surrey/Langley area. Following his pre-dental training at Simon Fraser University, he received his Doctor of Dental Medicine from the University of British Columbia in 1982 and his Certificate in Advanced Graduate Studies in Endodontics from Boston University’s Goldman School of Dental Medicine in 1995.

Dr. Bittner was in private practice in general dentistry for 11 years in Langley prior to his endodontic specialty training. He has a wide background in all facets of general dentistry, with advanced dental training in prosthetic dentistry from respected educational facilities such as Creating Restorative Excellence in Tacoma, Washington, and The Pankey Institute in Miami, Florida. He has been practicing the dental specialty of Endodontics since 1995.

He is a past president of the British Columbia Society of Endodontists, the Dental Specialists Society of British Columbia, and the Concentric Endodontic Study Club. Dr. Bittner is also a guest lecturer in the Faculty of Dentistry at the University of British Columbia.

On June 30, 2011, posted in: News for Doctors by