William J. Meyers

An evaluation of an electric pulp tester as a measure of analgesia in human vital teeth

The purpose of this study was to evaluate, with theAnalytic Technology electric pulp tester, clinical analgesia in normal, asymptomatic, and symptomatic human vital teeth. Group A consisted of 34 teeth that were classified as normal. Group B consisted of 33 asymptomatic teeth that had restorations, caries, or crown fracture. Group C consisted of 30 teeth with the clinical diagnosis of irreversible pulpitis. Two cartridges (3.6 ml) of 2% lidocaine with 1:100,000 epinephrine were administered by block and/or infiltration. The teeth were tested at various time intervals to determine if they responded to the maximum output (80/80) from the electric pulp tester. If the teeth responded, periodontal ligament injections were given until no response was recorded with the pulp tester. Clinical analgesia was then tested by performing endodontic procedures. The normal and asymptomatic groups had analgesia 100% of the time. In the teeth with irreversible pulpitis, 73% had clinical analgesia.

An evaluation of volumes and concentrations of lidocaine in human inferior alveolar nerve block

The purpose of this study was to evaluate, with the electric pulp tester, the anesthetic efficacy of 1.8 ml of 2% lidocaine with 1:100,000 epinephrine, 3.6 ml of 2% lidocaine with 1:200,000 epinephrine, and 1.8 ml of 4% lidocaine with 1:100,000 epinephrine in human inferior alveolar nerve block. Thirty subjects randomly received each of the solutions at three successive appointments. The first molar, canine, lateral incisor, and contralateral canine were tested with the pulp tester at various time intervals up to 55 min. Complete anesthesia was defined as an 80/80 reading with the pulp tester. No significant differences in anesthetic success or failure were found among the three solutions. Potential anesthetic problems (failure, noncontinuous anesthesia, slow onset, and short duration) occurred in 43 to 57% of the molars, in 43 to 60% of the canines, and in 57 to 80% of the lateral incisors. Complete anesthesia in the mandible is a meaningful clinical problem.

An in vitro comparison of the efficacy of the stepback technique versus a step-back/ultrasonic technique in human mandibular molars

This study compared the effect of the step-back preparation versus a step-back/ultrasound preparation on the tissue removal from the mesial root canals of 60 extracted human mandibular molars. The step-back/ultrasound preparation significantly cleaned isthmuses at both levels and canals at the 1-mm level more effectively than the step-back preparation. Statistical analysis indicated no significant difference, in canal cleanliness at the 3-mm level, between the step-back and the step-back/ ultrasound groups. There were no significant differences demonstrated in isthmus cleaning ability when comparing the step-back group with the control group, at both the 1- and 3-mm levels. At the 1-mm level, operator 1 significantly cleaned canals in the step-back group more effectively than operator 2. However, in the step-back/ultrasound group, no significant differences were demonstrated between operators in their ability to clean canals at this level. In both experimental groups, operator comparisons indicated no significant differences in isthmus cleanliness at the 1-mm level.

Anesthetic Efficacy of the Intraosseous Injection after an Inferior Alveolar Nerve Block

The purpose of this study was to determine the contribution of the intraosseous (IO) injection to the inferior alveolar nerve (IAN) block in human first molars. Using a repeated-measures design, 40 subjects randomly received either a combination IAN block + IO injection (on the distal of the first molar) using 2% lidocaine with 1:100,000 epinephrine or an IAN block+mock IO injection (gingival penetration only) at two successive appointments. The first molar and adjacent teeth, and contralateral canine (+/-controls) were blindly tested with an Analytic Technology pulp tester at 2-min cycles for 60 min. An 80 reading was used as the criterion for pulpal anesthesia. One hundred percent of the subjects had lip numbness with the IAN block. For the first molar, anesthetic success, defined as achieving an 80 reading within 15 min and keeping this reading for 60 min, was 42% with the IAN and 90% with the IAN + IO. Anesthetic failure defined as never achieving two 80 readings during the 60 min was 32% with the IAN and 0% with the IAN + IO. The onset of anesthesia was immediate with the IO injection. Eighty percent of the subjects sampled had a subjective increase in heart rate with the IO injection. The IO injection and postinjection questionnaire recorded low pain ratings.

An evaluation of 4% prilocaine and 3% mepivacaine compared with 2% lidocaine (1:100,000 epinephrine) for inferior alveolar nerve block

The purpose of this study was to measure the degree of anesthesia obtained with 4% prilocaine and 3% mepivacaine compared with 2% lidocaine (1:100,000 epinephrine) for inferior alveolar nerve block. Using a repeated measures design, 30 subjects randomly received an inferior alveolar injection using masked cartridges of each solution at three successive appointments. The first molar, first premolar, lateral incisor, and contralateral canine (control) were blindly tested with an Analytic Technology pulp tester at 3-min cycles for 50 min. Anesthetic success was defined as no subject response to the maximum output of the pulp tester (80 reading) within 16 min and maintenance of this reading for 50 min. Although subjects felt numb subjectively, anesthetic success as defined here occurred in 43 to 63% of the molars, in 53 to 67% of the premolars, and in 30 to 37% of the lateral incisors. No statistically significant differences in onset, success, or failure were found among the solutions. We conclude that the three preparations are equivalent for an inferior alveolar nerve block of 50-min duration.

A radioimmunoassay determination of the concentrations of prostaglandins E2 and F2α in painful and asymptomatic human dental pulps

The purpose of this study was to determine the concentrations of prostaglandin E 2 and prostaglandin F 2α in painful and asymptomatic human dental pulps. Pulps were obtained from three groups of teeth: uninflamed pulps, asymptomatic teeth with caries and/or large restorations, and symptomatic teeth with the clinical diagnosis of irreversible pulpitis. Pulps were dissected from the teeth and stored in liquid nitrogen. They were homogenized in 40% ethanol and a lipid solvent extraction was performed. Prostaglandin levels were measured using radioimmunoassay. The pulps which were likely to demonstrate inflammation had significantly higher mean concentrations of prostaglandin E 2 than did the uninflamed pulps (p 2 and prostaglandin F 2α than the asymptomatic pulps (p

Anesthetic efficacy of the periodontal ligament injection after an inferior alveolar nerve block

The purpose of this study was to determine the contribution of the periodontal ligament injection (PDL) to the inferior aveolar nerve (IAN) block in human first molars. Using a repeated-measures design, 40 subjects randomly received a combination IAN block and PDL injections of the first molar using 2% lidocaine with 1:100,000 epinephrine and a combination IAN block and mock PDL injections (needle penetration only) at two successive appointments. The first molar and adjacent teeth, and contralateral canine (positive and negative controls) were blindly tested with an Analytic Technology pulp tester at 2-min cycles for 60 min. Profound anesthesia was defined as no subject response at an 80 reading. One hundred percent of the subjects had lip numbness with the IAN block. When the combination IAN/PDL injections were compared with the IAN block, the incidence of successful pulpal anesthesia (80 reading) was significantly greater for the combination injections through the first 23 min of pulp testing. However, after 23 min, there was no increase in anesthetic success by adding the PDL to the IAN injection. We concluded that adding the PDL injection to an IAN block increased the incidence of pulpal anesthesia for the first 23 min in the first molar.

An evaluation of the incisive nerve block and combination inferior alveolar and incisive nerve blocks in mandibular anesthesia

The purpose of this study was to measure the degree of anesthesia obtained with the incisive nerve block, the inferior alveolar nerve block and a combination of both injections in mandibular teeth. Using a repeated measures design, 40 subjects randomly received an incisive nerve block, a conventional inferior alveolar nerve block, or a combination inferior alveolar nerve block plus an incisive nerve block using either lidocaine or saline (control), at four successive appointments. The mandibular teeth and contralateral canine (+/- controls) were blindly tested with an Analytic Technology pulp tester at 4-min cycles for 60 min. An 80 reading indicated complete pulpal anesthesia. The incisive nerve block alone did not result in successful pulpal anesthesia in the central, lateral, first, and second molars. It was successful in the first and second premolars but the duration was approximately 30 min. The combination inferior alveolar nerve block plus incisive nerve block was successful in the first and second premolars, and enhanced anesthesia for the laterals and first molars.

Anesthetic efficacy of the intraosseous injection in maxillary and mandibular teeth

OBJECTIVE The objective of this study was to determine the anesthetic efficacy of the intraosseous injection as a primary technique in human maxillary and mandibular teeth. STUDY DESIGN Forty subjects received two sets of intraosseous injections with 1.8 ml of 2% lidocaine with 1:100,000 epinephrine at two successive appointments. The experimental teeth consisted of 40 groups of maxillary and mandibular first molars and lateral incisors. Each experimental tooth and adjacent teeth were tested with an electric pulp tester at 4-minute cycles for 60 minutes. Anesthetic success was defined as no subject response to the maximum output of the pulp tester (80 reading) for two consecutive readings. RESULTS Anesthetic success occurred in 75% of mandibular first molars, in 93% of maxillary first molars, in 78% of mandibular lateral incisors, and in 90% of maxillary lateral incisors. Overall, for the intraosseous injection onset was immediate, the duration of pulpal anesthesia steadily declined over the 60 minutes, there was a 78% incidence of subjective increase in heart rate, the majority of the subjects had no pain or mild pain with perforation and solution deposition, and 3% of the subjects had slow healing perforation sites. CONCLUSIONS The results of this study indicate that the intraosseous injection may provide pulpal anesthesia in 75% to 93% of noninflamed teeth as a primary technique. However, the duration of pulpal anesthesia declines steadily over an hour.

The use of ultrasound for guiding needle placement for inferior alveolar nerve blocks

OBJECTIVE The degree of pulpal anesthesia obtained with an ultrasound-assisted inferior alveolar nerve block was compared to that obtained with a conventional inferior alveolar nerve block for mandibular teeth to determine whether needle placement assisted by ultrasound results in more successful anesthesia. STUDY DESIGN Through use of a repeated-measures design, each of 40 subjects randomly received an ultrasound-assisted inferior alveolar nerve block and a conventional inferior alveolar nerve block at 2 separate appointments. Mandibular anterior and posterior teeth were blindly tested by means of a pulp tester at 4-minute cycles for 60 minutes postinjection. Anesthesia was considered successful when 2 consecutive readings of 80 were obtained. RESULTS One hundred percent of the subjects had profound lip numbness with both the ultrasound-assisted inferior alveolar nerve block and the conventional inferior alveolar nerve block. For these 2 techniques, anesthetic success rates for individual teeth ranged from 38% to 92%. There were no significant differences (P > .05) between the 2 techniques. CONCLUSIONS It was concluded that accurate needle placement with ultrasound for the inferior alveolar nerve block did not result in more successful pulpal anesthesia in the mandible. Therefore, accuracy of needle placement is not the primary reason for pulpal anesthetic failure with this block.