Randomized Study of Phentolamine Mesylate for Reversal of Local Anesthesia

Local anesthetic solutions frequently contain vasoconstrictors to increase the depth and/or duration of anesthesia. Generally, the duration of soft-tissue anesthesia exceeds that of pulpal anesthesia. Negative consequences of soft-tissue anesthesia include accidental lip and tongue biting as well as difficulty in eating, drinking, speaking, and smiling. A double-blind, randomized, multicenter, Phase 2 study tested the hypothesis that local injection of the vasodilator phentolamine mesylate would shorten the duration of soft-tissue anesthesia following routine dental procedures. Participants (122) received one or two cartridges of local anesthetic/vasoconstrictor prior to dental treatment. Immediately after treatment, 1.8 mL of study drug (containing 0.4 mg phentolamine mesylate or placebo) was injected per cartridge of local anesthetic used. The phentolamine was well-tolerated and reduced the median duration of soft-tissue anesthesia in the lip from 155 to 70 min (p < 0.0001).

Anesthetic efficacy of unilateral and bilateral inferior alveolar nerve blocks to determine cross innervation in anterior teeth

OBJECTIVE

The purpose of this prospective randomized study was to measure the degree of anesthesia obtained with unilateral and bilateral inferior alveolar nerve blocks to determine whether cross innervation occurs in anterior teeth.

STUDY DESIGN

Through use of a repeated-measures design, 38 subjects randomly received unilateral or bilateral inferior alveolar nerve blocks at two separate appointments. Each inferior alveolar nerve block used 3.6 mL of 2% lidocaine with 1:100,000 epinephrine. Mandibular anterior teeth were blindly pulp-tested at 4-minute cycles for 60 minutes' postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained.

RESULTS

One hundred percent of the subjects had lip numbness with each of the inferior alveolar nerve block techniques. Anesthetic success rates of the unilateral inferior alveolar nerve block were 39% for the central incisor, 50% for the lateral incisor, and 68% for the canine. For the bilateral inferior alveolar nerve blocks, success rates were 66% for the central incisor, 74% for the lateral incisor, and 76% for the canine. The bilateral inferior alveolar nerve block success rates were significantly (P <.05) higher for the central and lateral incisors when compared with the success rates of the unilateral inferior alveolar nerve block.

CONCLUSIONS

Cross innervation does seem to occur in mandibular central and lateral incisors. However, the success rates in these teeth with bilateral inferior alveolar nerve blocks were below 75%. The failure of the inferior alveolar nerve blocks to anesthetize the anterior teeth was the overriding reason for failure. Clinically, bilateral inferior alveolar nerve blocks to provide profound pulpal anesthesia in mandibular anterior teeth are not recommended on the basis of the results of this study.

Effect of apical trephination on postoperative pain and swelling in symptomatic necrotic teeth

The purpose of this prospective, randomized, blinded study was to determine the effect of apical trephination on postoperative pain and swelling in symptomatic necrotic teeth. Fifty emergency patients participated, and each had a clinical diagnosis of a symptomatic necrotic tooth with associated periapical radiolucency. After endodontic treatment, patients randomly received either an apical trephination or mock trephination procedure. The trephination procedure used a Stabident perforator to provide an initial opening in the cortical bone that was enlarged with files (#25 through #120) and an endodontic spoon. Postoperatively, each patient received: ibuprofen; acetaminophen with codeine (30 mg); and a 7-day diary to record pain, percussion pain, swelling, and number and type of pain medication taken. Results demonstrated the use of an apical trephination procedure did not significantly (p > 0.05) reduce pain, percussion pain, swelling, or number of ibuprofen tablets taken in symptomatic necrotic teeth with periapical radiolucencies. The trephination procedure did significantly (p < 0.05) reduce the use of acetaminophen with codeine overall for the 7 days. In conclusion, because there was not a significant reduction in pain, percussion pain, or swelling we cannot recommend the routine use of an apical trephination procedure, as used in this study, in symptomatic necrotic teeth with radiolucencies.

Anesthetic efficacy of ropivacaine in maxillary anterior infiltration

OBJECTIVE

The purpose of this prospective, randomized double-blind study was to evaluate and compare the anesthetic efficacy of 0.5% ropivacaine with 1:200,000 epinephrine, of 0.5% ropivacaine, and of 0.5% bupivacaine with 1:200,000 epinephrine in maxillary lateral incisor infiltrations.

STUDY DESIGN

Forty subjects randomly received, in a double-blind manner, 3 infiltrations at 3 separate appointments, in a repeated-measures design. The injections consisted of an infiltration of 1.8 mL of 0.5% ropivacaine plain, an infiltration of 1.8 mL of 0.5% ropivacaine with 1:200,000 epinephrine, and an infiltration of 1.8 mL of 0.5% bupivacaine with 1:200,000 epinephrine (control solution). The maxillary lateral incisor pulpal anesthesia was evaluated with an electric pulp tester at 2-minute cycles for 90 minutes after injection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained. The duration of pulpal anesthesia was recorded as the last 80 reading.

RESULTS

One hundred percent of the subjects had lip numbness with all solutions. The anesthetic success rates for ropivacaine plain, ropivacaine with epinephrine, and bupivacaine with epinephrine were 68%, 75%, and 80%, respectively. There were no significant differences (P >.05) among the solutions. The duration of pulpal anesthesia (80 readings) for ropivacaine plain, ropivacaine with epinephrine, and bupivacaine with epinephrine was 13 minutes, 33 minutes, and 33 minutes, respectively. Ropivacaine plain had a significantly shorter duration of pulpal anesthesia than ropivacaine with epinephrine.

CONCLUSIONS

We concluded that 0.5% ropivacaine with 1:200,000 epinephrine was equivalent to 0.5% bupivacaine with 1:200,000 epinephrine in pharmacologic action. The duration of pulpal anesthesia was less for ropivacaine without epinephrine. Ropivacaine with epinephrine has the potential to replace bupivacaine with epinephrine in clinical dental practice because of the decreased potential for cardiac and central nervous system toxicity.

Effect of penicillin on postoperative endodontic pain and swelling in symptomatic necrotic teeth

The purpose of this prospective, randomized, double-blind, placebo-controlled study was to determine the effect of penicillin on postoperative pain and swelling in symptomatic necrotic teeth. Forty-one emergency patients participated and each had a clinical diagnosis of a symptomatic necrotic tooth with associated periapical radiolucency. After endodontic treatment patients randomly received a 7-day oral dose (twenty-eight 500 mg capsules to be taken every 6 h) of either penicillin or a placebo control in a double-blind manner. Patients also received ibuprofen; acetaminophen with codeine (30 mg); and a 7-day diary to record pain, percussion pain, swelling, and number and type of pain medication taken. The majority of patients with symptomatic necrotic teeth had significant postoperative pain and require analgesic medication to manage this pain. The administration of penicillin postoperatively did not significantly (p > 0.05) reduce pain, percussion pain, swelling, or the number of analgesic medications taken for symptomatic necrotic teeth with periapical radiolucencies.

Effect of prophylactic amoxicillin on endodontic flare-up in asymptomatic, necrotic teeth

The purpose of this prospective, randomized, double-blind, placebo-controlled study was to determine the effect of prophylactic amoxicillin on the occurrence of endodontic flare-up in asymptomatic, necrotic teeth. Seventy patients participated and had a clinical diagnosis of an asymptomatic, necrotic tooth with associated periapical radiolucency. One hour before endodontic treatment, patients randomly received either 3 g of amoxicillin or 3 g of a placebo control in a double-blind manner. After endodontic treatment, each patient received: ibuprofen; acetaminophen with codeine (30 mg); and a 5 1/2-day diary to record pain, swelling, percussion pain, and number and type of pain medication taken. The results demonstrated 10% of the 70 patients had a flare-up characterized by moderate-to-severe postoperative pain or swelling that began approximately 30 h after endodontic treatment and persisted for an average of 74 h. Of the seven patients who had flare-ups, 4 were in the amoxicillin group and 3 were not. Prophylactic amoxicillin did not significantly (p = 0.80) influence the endodontic flare-up. We concluded that a prophylactic dose of amoxicillin before endodontic treatment of asymptomatic, necrotic teeth had no effect on the endodontic flare-up.

Anesthetic efficacy of a combination of hyaluronidase and lidocaine with epinephrine in inferior alveolar nerve blocks

The purpose of this prospective, randomized, double-blind study was to determine the anesthetic efficacy of a buffered lidocaine with epinephrine solution compared to a combination buffered lidocaine with epinephrine plus hyaluronidase solution in inferior alveolar nerve blocks. Thirty subjects randomly received an inferior alveolar nerve block using 1 of the 2 solutions at 2 separate appointments using a repeated-measures design. Mandibular anterior and posterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive readings of 80 were obtained. A postoperative survey was used to measure pain and trismus. The results demonstrated 100% of the subjects had profound lip numbness with both solutions for inferior alveolar nerve blocks. The anesthetic success rates for individual teeth ranged from 20 to 80%. There were no significant differences (P > .05) between the 2 solutions. However, the combination lidocaine/hyaluronidase solution resulted in a significant increase in postoperative pain and trismus. It was concluded that adding hyaluronidase to a buffered lidocaine solution with epinephrine did not statistically increase the incidence of pulpal anesthesia in inferior alveolar nerve blocks and, because of its potential tissue damaging effect, it should not be added to local anesthetic solutions for inferior alveolar nerve blocks.

Anesthetic efficacy of infiltrations in mandibular anterior teeth

The purpose of this prospective, randomized, double-blind study was to measure the degree of anesthesia obtained with a labial infiltration of either 2% lidocaine with 1:50,000 or 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Another objective was to measure the degree of anesthesia obtained with a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Through use of a repeated-measures design, 40 subjects randomly received a labial infiltration at the lateral incisor apex of either 1.8 mL of 2% lidocaine with 1:100,000 epinephrine or 1.8 mL of 2% lidocaine with 1:50,000 epinephrine at 2 separate appointments. An additional 40 subjects received a lingual infiltration at the lateral incisor apex of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine. The mandibular anterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained. For the 3 infiltrations, success rates for the lateral incisor ranged from 43 to 50%. Adjacent teeth had success rates of 27 to 63%. There was no significant difference (P > 0.05) in success between the labial infiltration of 2% lidocaine with 1:100,000 epinephrine and 2% lidocaine with 1:50,000 epinephrine or the lingual infiltration of 2% lidocaine with 1:100,000 epinephrine when compared with the labial infiltration of 2% lidocaine with 1:100,000 epinephrine. Duration of pulpal anesthesia declined steadily for all solutions over the 60 minutes. In conclusion, the success rate of 43-50% and declining duration of pulpal anesthesia over an hour indicates that a labial infiltration of 1.8 mL of either 2% lidocaine with 1:100,000 epinephrine or 1: 50,000 epinephrine or a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine over the lateral incisor apex cannot be recommended clinically to provide profound pulpal anesthesia.

Pain reduction in untreated irreversible pulpitis using an intraosseous injection of Depo-Medrol

The purpose of this prospective, double-blind, randomized study was to evaluate pain reduction using an intraosseous injection of slow-releasing methylprednisolone in teeth with irreversible pulpitis. Forty subjects presenting for emergency treatment completed the study. Each subject had a tooth with a clinical diagnosis of irreversible pulpitis with actively associated moderate to severe pain. After local anesthesia was attained, the subjects were randomly assigned to receive an intraosseous injection of either 1.0 ml of Depo-Medrol (40 mg) or 1.0 ml of sterile saline (control). No endodontic therapy was begun at the initial appointment. The subjects received ibuprofen and Tylenol #3 and completed a 7-day questionnaire on pain, percussion pain, and analgesic medications taken each day. Over the 7-day observation period, the subjects who received the intraosseous injection of Depo-Medrol reported significantly (p < 0.05) less pain and percussion pain while taking significantly (p < 0.05) fewer pain medications. Clinically the intraosseous injection of Depo-Medrol could be used to temporarily alleviate the symptoms of irreversible pulpitis until definitive treatment can be rendered.

Effect of systemic penicillin on pain in untreated irreversible pulpitis

OBJECTIVE

The purpose of this prospective, randomized, double-blind study was to determine the effect of penicillin on pain in untreated teeth diagnosed with irreversible pulpitis.

STUDY DESIGN

Forty emergency patients participated, and each had a clinical diagnosis of an irreversible pulpitis. Patients randomly received a 7-day oral dose (28 capsules, 500 mg each, to be taken every 6 hours) of either penicillin or a placebo control in a double-blind manner. No endodontic treatment was performed. Each patient also received ibuprofen; acetaminophen with codeine (30 mg); and a 7-day diary to record pain, percussion pain, and number and type of pain medication taken.

RESULTS

The administration of penicillin did not significantly (P >.05) reduce pain, percussion pain, or the number of analgesic medications taken by patients with untreated irreversible pulpitis. The majority of patients with untreated irreversible pulpitis had significant pain and required analgesics to manage this pain.

CONCLUSION

Penicillin should not be prescribed for untreated irreversible pulpitis because penicillin is ineffective for pain relief.

Effect of trephination on postoperative pain and swelling in symptomatic necrotic teeth

OBJECTIVE

The purpose of this prospective, randomized, blinded study was to determine the effect of trephination on postoperative pain and swelling in symptomatic necrotic teeth.

STUDY DESIGN

Fifty emergency patients participated, and each had a clinical diagnosis of a symptomatic necrotic tooth with associated periapical radiolucency. After endodontic treatment, patients randomly received either a trephination or mock trephination procedure. The trephination procedure used an intraosseous perforator to provide an initial opening in the cortical bone that was enlarged with files (No. 25 through No. 70) and an endodontic spoon. After surgery, each patient received ibuprofen; acetaminophen with codeine (30 mg); and a 7-day diary to record pain, percussion pain, swelling, and number and type of pain medication taken.

RESULTS

The majority of patients with symptomatic necrotic teeth had significant postoperative pain and required analgesics to manage this pain. The use of a trephination procedure with an intraosseous perforator, files, and a spoon excavator did not significantly reduce pain, percussion pain, swelling, or the number of analgesic medications taken in symptomatic necrotic teeth with periapical radiolucencies (P >.05).

CONCLUSION

We cannot recommend the routine use of a trephination procedure, as used in this study, for relief of pain in symptomatic necrotic teeth with radiolucencies.

Anesthetic efficacy and heart rate effects of the intraosseous injection of 1.5% etidocaine (1:200,000 epinephrine) after an inferior alveolar nerve block

OBJECTIVE

The purpose of this study was to determine the anesthetic efficacy and heart rate effects of an intraosseous (IO) injection of 1.5% etidocaine with 1:200,000 epinephrine after an inferior alveolar nerve block.

STUDY DESIGN

In a repeated-measures designed study, 48 subjects randomly received 2 combinations of injections at 2 separate appointments. The combinations were an inferior alveolar nerve (IAN) block (with 3% mepivacaine) + IO injection with 1.8 mL of 1.5% etidocaine hydrochloride containing 1:200,000 epinephrine, and an IAN + mock IO injection. The first molar was blindly tested with a pulp tester at 2-minute cycles for 60 minutes after the injection. Anesthesia was considered successful when 2 consecutive 80 readings (no subject response) were obtained. Heart rate (pulse rate) was measured with a pulse oximeter.

RESULTS

Lip numbness occurred in 100% of the subjects with both the techniques. For the first molar, anesthetic success for the IAN + mock IO and the IAN + IO etidocaine hydrochloride groups, respectively, were 81% and 100%. The differences were significant (P <.05) when the IAN + IO etidocaine hydrochloride technique was compared with the IAN + mock IO. A mean increase in heart rate of 32 beats/min occurred in 90% of the subjects with the IO injection of the etidocaine hydrochloride solution. In 89% of these subjects, the heart rate returned to within 5 beats of baseline values 4 minutes or less after solution deposition.

CONCLUSIONS

The IO injection of 1.8 mL of 1.5% etidocaine hydrochloride with 1:200,000 epinephrine, when used to augment an inferior alveolar nerve block, significantly increased anesthetic success in the first molar. The majority of subjects receiving the IO injection of the etidocaine hydrochloride solution had a transient increase in heart rate.

Anesthetic efficacy and heart rate effects of the intraosseous injection of 3% mepivacaine after an inferior alveolar nerve block

OBJECTIVE

The purpose of this study was to determine the anesthetic efficacy and heart rate effects of an intraosseous injection of 3% mepivacaine after an inferior alveolar nerve block.

STUDY DESIGN

Through use of a repeated-measures design, each of 48 subjects randomly received 2 combinations of injections at 2 separate appointments. The combinations were (1) an inferior alveolar nerve block (with 1.8 mL of 3% mepivacaine) + intraosseous injection with 1.8 mL of 3% mepivacaine and (2) an inferior alveolar nerve (with 1. 8 mL of 3% mepivacaine) + mock intraosseous injection. The first molar was blindly pulp tested at 2-minute cycles for 60 minutes postinjection. Anesthesia was considered successful with 2 consecutive 80 readings. Heart rate (pulse rate) was measured with a pulse oximeter.

RESULTS

All subjects had lip numbness with both of the inferior alveolar nerve + intraosseous techniques. Anesthetic success for the first molar was significantly increased for 30 minutes with intraosseous injection of mepivacaine in comparison with the inferior alveolar nerve block alone (mock intraosseous injection). Subjects receiving the intraosseous injection of mepivacaine experienced minimal increases in heart rate.

CONCLUSIONS

The intraosseous injection of 1.8 mL of 3% mepivacaine, when used to augment an inferior alveolar nerve block, significantly increased anesthetic success for 30 minutes in the first molar. The 3% mepivacaine had a minimal effect on heart rate and would be useful in patients with contraindications to epinephrine use.

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.

Anesthetic efficacy of the mylohyoid nerve block and combination inferior alveolar nerve block/mylohyoid nerve block

OBJECTIVE

The purpose of this study was to measure the degree of anesthesia obtained with the mylohyoid nerve block and the combination mylohyoid nerve block/conventional inferior alveolar nerve (IAN) block in mandibular teeth.

STUDY DESIGN

With the use of a repeated-measures design, 30 subjects randomly received each of 3 combinations of injections at 3 separate appointments. The combinations were as follows: mylohyoid nerve block (1.8 mL of 2% lidocaine with 1:100,000 epinephrine) + IAN block (3.6 mL of 2% lidocaine with 1:100,000 epinephrine); mock mylohyoid nerve block + IAN block (3.6 mL of 2% lidocaine with 1:100,000 epinephrine); mylohyoid nerve block (1.8 mL of 2% lidocaine with 1:100,000 epinephrine) + mock IAN block. The mylohyoid injections were aided by the use of a peripheral nerve stimulator. Mandibular anterior and posterior teeth were blindly tested with a pulp tester at 4-minute cycles for 60 minutes postinjection. Anesthesia was considered successful when 2 consecutive 80 readings were obtained.

RESULTS

One hundred percent of the subjects had lip numbness with the mylohyoid nerve block + IAN block and mock mylohyoid nerve block + IAN block techniques. For these 2 techniques, anesthetic success rates were higher in posterior teeth (73% to 93%) than in anterior teeth (33% to 60%). There were no significant differences (P > .05) between the 2 techniques. The mylohyoid nerve block + mock IAN block technique resulted in a very low success rate (0% to 17%) and was significantly different (P < .05) from the mylohyoid nerve block + IAN block technique.

CONCLUSIONS

The results of this study suggest that the mylohyoid nerve block does not by itself predictably provide pulpal anesthesia in mandibular teeth and does not significantly enhance pulpal anesthesia when administered in combination with the IAN block.

CARDIOVASCULAR EFFECTS OF INTRAOSSEOUS INJECTIONS OF 2 PERCENT LIDOCAINE WITH 1:100,000 EPINEPHRINE AND 3 PERCENT MEPIVACAINE

BACKGROUND

Because a number of patients have reported an increase in heart rate with the intraosseous, or i.o., injection, it is important to evaluate changes in the cardiovascular system with this injection technique. The purpose of this study was to determine the cardiovascular effects of an i.o. injection of 2 percent lidocaine with 1:100,000 epinephrine and 3 percent mepivacaine.

METHODS

With the use of a repeated-measures design, the authors randomly assigned 42 subjects to receive i.o. injections of 1.8 milliliters of 2 percent lidocaine with 1:100,000 epinephrine or 1.8 mL of 3 percent mepivacaine in a double-blinded manner at two appointments. At each appointment the authors monitored electrocardiographic findings, cardiac rate, systolic and diastolic blood pressure, and mean arterial pressure before, during and after administration of anesthetic solutions.

RESULTS

With the 2 percent lidocaine with 1:100,000 epinephrine solution, 28 (67 percent) of 42 subjects experienced an increase in heart rate that might be attributed to the effect of the epinephrine. In 22 (79 percent) of these subjects, the heart rate returned to within 5 beats of baseline values within four minutes after solution deposition. The authors found no significant increase in heart rate in subjects receiving the 3 percent mepivacaine. No significant differences (P > .05) were found in mean diastolic, mean systolic or mean arterial blood pressure values between the subjects receiving 2 percent lidocaine with 1:100,000 epinephrine and those receiving 3 percent mepivacaine.

CONCLUSIONS

The majority of subjects receiving the i.o. injection of the 2 percent lidocaine-epinephrine solution experienced a transient increase in heart rate. No significant increase in heart rate was seen with the i.o. injection of 3 percent mepivacaine.

CLINICAL IMPLICATIONS

While patients would likely notice the heart rate increase with the lidocaine-epinephrine solution, it would not be clinically significant in most healthy patients. In patients whose medical condition, drug therapies or epinephrine sensitivity suggests caution, 3 percent mepivacaine is a good alternative for i.o. injections.

Anesthetic efficacy and heart rate effects of the supplemental intraosseous injection of 2% mepivacaine with 1:20,000 levonordefrin

OBJECTIVE

The purpose of this study was to determine the anesthetic efficacy and heart rate effects of a supplemental intraosseous injection of 2% mepivacaine with 1:20,000 levonordefrin.

STUDY DESIGN

Through use of a repeated-measures design, 40 subjects randomly received 3 combinations of injections at 3 separate appointments. The combinations were as follows: inferior alveolar nerve (IAN) block (with 3% mepivacaine) + intraosseous injection of 1.8 mL of 2% mepivacaine with 1:20,000 levonordefrin; IAN block + intraosseous injection of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine (positive control); IAN block + mock intraosseous injection (negative control). Each first molar, second molar, and second premolar was blindly tested with a pulp tester at 2-minute cycles for 60 minutes after injection. Anesthesia was considered successful when 2 consecutive readings of 80 were obtained. Heart rate (pulse rate) was measured with a pulse oximeter.

RESULTS

One hundred percent of the subjects had lip numbness with the IAN block + intraosseous mock technique and IAN block + intraosseous techniques. The anesthetic success rates for IAN block + mock intraosseous injection, IAN block + intraosseous lidocaine, and IAN block + intraosseous mepivacaine, respectively, were as follows: 80%, 100%, and 100% for the first molar; 90%, 100%, and 100% for the second molar; 77%, 97%, and 97% for the second premolar. For the first molar and second premolar, the differences were significant (P< .05) when the intraosseous mepivacaine and lidocaine techniques were compared with the IAN block + mock intraosseous injection. There were no significant differences between the intraosseous mepivacaine and lidocaine techniques. Eighty percent of the subjects had a mean increase in heart rate of 23-24 beats per minute with the intraosseous injection of the mepivacaine and lidocaine solutions; there were no significant differences between results with the 2 solutions.

CONCLUSIONS

We concluded that intraosseous injection of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine or 2% mepivacaine with 1:20,000 levonordefrin, used to supplement an IAN block, significantly increased anesthetic success in first molars and second premolars. The 2 solutions were equivalent with regard to intraosseous anesthetic success rate, failure rate, and heart rate increase after IAN block.

Anesthetic efficacy of the intraosseous injection of 0.9 mL of 2% lidocaine (1:100,000 epinephrine) to augment an inferior alveolar nerve block

OBJECTIVE

The purpose of this study was to determine the anesthetic efficacy of an intraosseous injection of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine to augment an inferior alveolar nerve block in mandibular posterior teeth.

STUDY DESIGN

With the use of a repeated-measures design, each of 38 subjects randomly received one or the other of 2 combinations of injections at 2 separate appointments. The combinations were inferior alveolar nerve block + intraosseous injection (on the distal of the second premolar) through use of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine and inferior alveolar nerve block + mock intraosseous injection. The first molar, second premolar, and second molar were blindly tested with an Analytic Technology pulp tester at 2-minute cycles for 120 minutes postinjection. Anesthesia was considered successful when 2 consecutive 80 readings were obtained.

RESULTS

One hundred percent of the subjects had lip numbness with the inferior alveolar nerve block + intraosseous injection combination technique. The respective anesthetic success rates for the inferior alveolar nerve block + mock intraosseous injection combination and the inferior alveolar nerve block + intraosseous injection combination were 60% and 100% for the second premolar, 71% and 95% for the first molar, and 74% and 87% for the second molar. The differences were significant (P < .05) for the second premolar through 50 minutes and for the first molar through 20 minutes. There were no significant (P > .05) differences for the second molar. Sixty-eight percent of the subjects had a subjective increase in heart rate with the intraosseous injection.

CONCLUSIONS

The results of this study indicate that the supplemental intraosseous injection of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine, given distal to the second premolar, significantly increased the success of pulpal anesthesia in the second premolar (for 50 minutes) and first molar (for 20 minutes) in comparison with the inferior alveolar nerve block alone. The intraosseous injection did not statistically increase success in the second molar.

Anesthetic efficacy of the supplemental intraosseous injection of 2% lidocaine with 1:100,000 epinephrine in irreversible pulpitis

The purpose of this study was to determine the anesthetic efficacy of a supplemental intraosseous injection of 2% lidocaine with 1:100,000 epinephrine in teeth diagnosed with irreversible pulpitis. Fifty-one patients with symptomatic, vital maxillary, and mandibular posterior teeth diagnosed with irreversible pulpitis received conventional infiltrations or inferior alveolar nerve blocks. Pulp testing was used to determine pulpal anesthesia after "clinically successful" injections. Patients who were positive to the pulp tests, or were negative to the pulp tests but felt pain during endodontic access, received an intraosseous injection using 1.8 ml of 2% lidocaine with 1:100,000 epinephrine. The results demonstrated that 42% of the patients who tested negative to the pulp tests reported pain during treatment and required supplemental anesthesia. Eighty-one percent of the mandibular teeth and 12% of maxillary teeth required an intraosseous injection due to failure to gain pulpal anesthesia. Overall, the Stabident intraosseous injection was found to be 88% successful in gaining total pulpal anesthesia for endodontic therapy. We concluded that, for posterior teeth diagnosed with irreversible pulpitis, the supplemental intraosseous injection of 2% lidocaine (1:100,000 epinephrine) was successful when conventional techniques failed.

Anesthetic efficacy of a repeated intraosseous injection given 30 min following an inferior alveolar nerve block/intraosseous injection

To determine whether a repeated intraosseous (IO) injection would increase or prolong pulpal anesthesia, we measured the degree of anesthesia obtained by a repeated IO injection given 30 min following a combination inferior alveolar nerve block/intraosseous injection (IAN/IO) in mandibular second premolars and in first and second molars. Using a repeated-measures design, we randomly assigned 38 subjects to receive two combinations of injections at two separate appointments. The combinations were an IAN/IO injection followed approximately 30 min later by another IO injection of 0.9 ml of 2% lidocaine with 1:100,000 epinephrine and a combination IAN/IO injection followed approximately 30 min later by a mock IO injection. The second premolar, first molar, and second molar were blindly tested with an Analytic Technology pulp tester at 2-min cycles for 120 min postinjection. Anesthesia was considered successful when two consecutive readings of 80 were obtained. One hundred percent of the subjects had lip numbness with IAN/IO and with IAN/IO plus repeated IO techniques. Rates of anesthetic success for the IAN/IO and for the IAN/IO plus repeated IO injection, respectively, were 100% and 97% for the second premolar, 95% and 95% for the first molar, and 87% and 87% for the second molar. The repeated IO injection increased pulpal anesthesia for approximately 14 min in the second premolar and for 6 min in the first molar, but no statistically significant differences (P > 0.05) were shown. In conclusion, the repeated IO injection of 0.9 ml of 2% lidocaine with 1:100,000 epinephrine given 30 min following a combination IAN/IO injection did not significantly increase pulpal anesthesia in mandibular second premolars or in first and second molars.

Anesthetic efficacy of the supplemental intraosseous injection of 3% mepivacaine in irreversible pulpitis

OBJECTIVE

To determine the efficacy of a supplemental intraosseous injection of 3% mepivacaine in mandibular posterior teeth with irreversible pulpitis. Intraosseous injection pain, subjective heart rate increase, and pain ratings during endodontic treatment were also assessed.

STUDY DESIGN

Forty-eight patients with irreversible pulpitis received conventional inferior alveolar nerve blocks. Electric pulp testing was used to determine pulpal anesthesia. Patients who were positive to the pulp testing, or negative to pulp testing but felt pain during endodontic treatment, received an intraosseous injection of 1.8 ml of 3% mepivacaine. A second intraosseous injection of 3% mepivacaine (1.8 ml) was given if the first injection was unsuccessful.

RESULTS

Seventy-five percent of patients required an initial intraosseous injection because of failure to gain pulpal anesthesia. The inferior alveolar block was 25% successful; the first intraosseous injection increased success to 80%. A second intraosseous injection further increased success to 98%. These differences were significant (p < 0.05). Eight percent (4/48) of the initial intraosseous injections resulted in solution being expressed into the oral cavity: these were considered technique failures.

CONCLUSIONS

For mandibular posterior teeth with irreversible pulpitis, a supplemental intraosseous injection of 3% mepivacaine increased anesthetic success. A second intraosseous injection, when necessary, further improved success.

Anesthetic efficacy of the intraosseous injection of 2% lidocaine (1:100,000 epinephrine) and 3% mepivacaine in mandibular first molars

OBJECTIVES

This study compared the anesthetic efficacy of a primary intraosseous injection of 2% lidocaine with 1:100,000 epinephrine and 3% mepivacaine in human mandibular first molars. Injection pain and healing postoperatively were also assessed for the intraosseous injection.

STUDY DESIGN

With the use of a repeated-measures design, 42 subjects randomly received intraosseous injections of 1.8 ml of 2% lidocaine with 1:100,000 epinephrine or 1.8 ml of 3% mepivacaine in a double-blind manner at two successive appointments. The first molar and adjacent teeth were blindly tested with an electric pulp tester at 2-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 74% of the first molars with 2% lidocaine with 1:100,000 epinephrine and in 45% with 3% mepivacaine. The difference was statistically significant (p < 0.05). Overall, onset was rapid for the intraosseous injections, the duration of pulpal anesthesia steadily declined over the 60 minutes, the majority of the subjects had no pain or mild pain with perforation and solution deposition, and 5% of the subjects had delayed healing at the perforation sites.

CONCLUSIONS

The results of this study indicate that the primary intraosseous injection of 2% lidocaine with 1:100,000 epinephrine is more successful and results in a longer duration of pulpal anesthesia as compared with 3% mepivacaine in noninflamed mandibular first molars. Most subjects reported no or mild pain during perforation and injection.

Peripheral opioid analgesia in teeth with symptomatic inflamed pulps

The purpose of this study was to investigate the ability of low-dose fentanyl to produce analgesia when administered via the periodontal ligament injection in teeth with symptomatic, inflamed pulps. All subjects presented for emergency treatment with moderate to severe pain and had a posterior tooth with a clinical diagnosis of irreversible pulpitis. Twenty subjects randomly received either 10 micrograms fentanyl citrate or saline placebo via the periodontal ligament injection in a double-blind manner. The subjects rated their pain prior to injection and rated pain intensity and pain half gone for 59 min postinjection. Low-dose fentanyl delivered via the periodontal ligament injection in inflamed teeth provided significantly greater analgesia than the saline placebo (P < 0.05). Since the dose of fentanyl used was less than the dose required to provide analgesia by a central mechanism, the results of this study may be consistent with a peripheral opioid mechanism of action.

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.

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.

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 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.

An in vivo evaluation of the efficacy of ultrasound after step-back preparation in mandibular molars

This study histologically compared the in vivo debridement efficacy of the step-back preparation versus a step-back/ultrasound preparation in the mesial root canals of vital mandibular molars. Group 1 consisted of 17 teeth prepared with a step-back technique using intermittent irrigation with 5.25% sodium hypochlorite. Group 2 consisted of 17 teeth prepared with a step-back technique as in group 1 followed by 3 min of ultrasonic instrumentation per canal utilizing a #15 Endosonic file in an Enac unit set at 3.5. An additional 6 ml/canal of 5.25% sodium hypochlorite was used during the ultrasonic preparation. Eight uninstrumented mandibular molars served as histological controls. Following extraction and histological preparation, 0.2-microns cross-sections from the 1- to 3-mm apical levels of the canal and isthmus were evaluated for percentage of tissue removal using an Olympus CUE-2 Image Analysis System. Factorial analysis of variance indicated canal and isthmus cleanliness values were significantly higher, at all 11 apical levels, with the ultrasonic technique. Sample values at the 1-, 2-, and 3-mm levels for the step-back and step-back/ultrasonic techniques, respectively, were: canal, 64% versus 92%, 81% versus 97%, and 90% versus 99.9%; isthmus, 2% versus 46%, 15% versus 60%, and 16% versus 83%.

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.