ROSEMONT, Ill. – A lower dose of the local anesthetic lidocaine can be made as effective as a higher dosage by changing the formulation’s acidity, giving oral and maxillofacial surgeons and other dental clinicians more options when administering the drug, according to a new study.
The study, published in the October issue of the Journal of Oral and Maxillofacial Surgery, found 1 percent lidocaine numbed the midface area quicker than 2 percent lidocaine when the 1 percent anesthetic was buffered, meaning the drug had a more neutral acidity than the 2 percent non-buffered anesthetic. With a more neutral acidity, more of the lidocaine impacts the targeted nerve fibers so less is needed to be effective, researchers wrote.
The authors said specific groups of patients could benefit from reduced drug dosages including “pediatric patients whose lidocaine drug dosages and treatment are now limited by caution not to exceed maximum blood lidocaine levels based on body weight.” They said other patients also may benefit, particularly those with compromised liver function.
“Reducing drug dosages while retaining the benefits of effective responses to local anesthetics should be explored further,” the authors wrote in the official journal of the American Association of Oral and Maxillofacial Surgeons.
To compare the types of anesthetic, researchers administered the drugs to adult patients during a two-week period. Using a testing technique that sends electric currents through tissues, researchers could stimulate the participants’ first molar and canine teeth. The investigators then recorded participant pain levels during the injection and the time it took to numb the midface area.
Of the participants, 58 percent reported less pain after receiving buffered 1 percent lidocaine than non-buffered 2 percent lidocaine. No matter the drug, pain levels overall were low with an average of four on a 10-point scale.
In addition, 58 percent of participants reported a shorter time to midface numbness after receiving buffered 1 percent lidocaine than non-buffered 2 percent lidocaine, although researchers noted the difference between the two drugs was not significant.
The time to recovery of sensation was similar for both drug formulations when using the cold test. However, time to return to sensation took significantly longer using the non-buffered drug on the molar and canine with electric pulp testing.
The researchers said they are unsure if the study findings would hold true for patients with more compromised health and another anesthesia technique. In this study, the anesthetic was administered with a maxillary field block, a type of injection.
The authors of “Buffered 1% Lidocaine With Epinephrine Can Be as Effective as Non-buffered 2% Lidocaine With Epinephrine for Maxillary Field Block” – all from the University of North Carolina in Chapel Hill, N.C. – are: James A. Phero, DDS, MD, Department of Oral and Maxillofacial Surgery; Victor T. Warren, BS; Anson G. Fisher, BA; Eric M. Rivera, DDS, Distinguished Associate Professor, Department of Endodontics; Glenn Reside, DDS, Clinical Associate Professor, Department of Oral and Maxillofacial Surgery; Ceib Phillips, Ph.D., MPH, Professor, Department of Orthodontics; and Raymond P. White Jr., DDS, PhD, Distinguished Professor, Department of Oral and Maxillofacial Surgery; all from the School of Dentistry; Pooja T. Saha, BSPH, Doctoral Candidate, Department of Biostatistics at the Gillings School of Public Health.
The full article can be accessed at http://www.joms.org/article/S0278-2391(17)30350-6/fulltext.