- Email: [email protected]
The periodontal ligament injection: A comparison of 2% lidocaine, 3% mepivacaine, and 1:100,000 epinephrine to 2% lidocaine with 1: 100,000 epinephrine in human mandibular premolars
0099-2399/88/1408-0397/$02.00/0 JOUANA~ OF ENDODONTICS
Printed in U.S.A. VOL. 14,No.8,AUGUST1988
Copyright C> 1988 by The American Association of Endodontists
CLINICAL ARTICLES The Periodontal Ligament Injection: A Comparison of 2% Lidocaine, 3% Mepivacaine, and 1:100,000 Epinephrine to 20/0 Lidocaine with 1:100,000 Epinephrine in Human Mandibular Premolars John Richard Schleder, DDS, MS, AI Reader, DDS, MS, Mike Beck, DDS, MA, and William J. Meyers, DMD, MEd
gamentary anesthesia has been advocated as a primary and a supplemental injection technique (I, 2, 4-10). Overall success rates reported for this injection technique, in clinical studies (1,2,4, 8,9), have ranged from 81 to 86% when used as a primary injection, and from 83 to 92% when used for supplemental anesthesia. Three studies (2, 10, 11) have compared the use of different anesthetic solutions with the periodontal ligament injection. Malamed (2) reported success rates of74 and 84% for different anesthetics when periodontal ligament injections were given as the primary injection technique for patients undergoing routine dental procedures. The number of injections were too small to show any significant differences in efficacy or duration of the solutions. Kaufman et al. (10) and Johnson et al. (II) demonstrated that the duration of pulpal and soft tissue anesthesia, produced by periodontal ligament injections, was related to the solution used and specifically to the concentration of the vasoconstrictor. Therefore, there is little comparative information on the efficacy or duration of various anesthetic solutions used with this injection technique. The purpose of this study was to evaluate the anesthetic efficacy of the periodontal ligament injection by comparing three solutions, 2% lidocaine, 3% rnepivacaine, and 1: 100,000 epinephrine with 2% lidocaine with I: 100,00 epinephrine. Human mandibular premolars were tested for anesthesia by using an electric pulp tester.
The purpose of this study was to evaluate, with an electric pulp tester, the anesthetic efficacy of the periodontal ligament injection. Two percent lidocaine, 3% mepivacaine, and 1:100,000 epinephrine were compared with 2% lidocaine with 1:100,000 epinephrine in human mandibular premolars. Two percent lidocaine with 1:100,000 epinephrine anesthetized significantly more first premolars (87% success), for a longer duration (approximately 20 min), than any of the test solutions. Three percent mepivacaine anesthetized 42% of the teeth and had a duration of approximately 4 min. Two percent lidocaine anesthetized 14% of the teeth and had a duration of 2 to 4 min. The epinephrine solution did not anesthetize any teeth. Two percent lidocaine with epinephrine anesthetized more adjacent teeth, both mesial (45% success rate) and distal (78% success rate), for a longer duration than any of the test solutions. Initial needle penetrations and injections of 2% lidocaine with epinephrine, in clinically healthy teeth, were only mildly discomforting. Postinjection discomfort was experienced by 88% of the SUbjects and 49% reported that their tooth felt high in occlusion. No clinically observable pulpal or periodontal damage was seen at 4 wk postinjection.
MATERIALS AND METHODS Seventy-five dental and dental hygiene students, 40 males and 35 females ranging in age from 20 to 31 yr, participated in this study. Based on a clinical written history and oral questioning, the subjects were judged to be in good health, were currently taking no medication, and had never had an allergic or toxic reaction to a local anesthetic agent. The study was approved by the Human Subjects Committee at The Ohio State University and written consent was obtained from each subject.
Local anesthesia is the primary method used in dentistry to control patients' pain. However, even in the presence of adequate soft tissue anesthesia, there may be incomplete pulpal anesthesia (1,2). This is particularly true in the mandible where obtaining profound pulpal anesthesia may be difficult (1-3). Recently, the periodontal ligament injection has received much attention in the dental literature (I, 2, 4-10). Intrali397
398
Journal of Endodontics
SChleder et al.
The experimental solutions tested were 2% lidocaine (Astra Pharmaceuticals Products, Inc., Worchester, MA), 3% mepivacaine (Cook-Waite Lab. Inc., New York, NY), and I: 100,000 epinephrine (Elkins-Senn, Inc., Cherry Hill, NJ). These solutions were compared with the control solution, 2% lidocaine with I: 100,000 epinephrine (Astra Pharmaceuticals). The epinephrine solution was prepared in the following manner. Empty anesthetic cartridges and plungers were washed for 5 min with soap and water using a nylon brush. All cartridges and plungers were then rinsed in two changes of distilled water for I min and autoclaved for 50 min. Using a sterile technique, cartridges were filled with 1.8 ml of sterile saline and 18.0 ~l of I: I,000 epinephrine using a Hamilton microliter syringe (Hamilton Co., Reno, NY). This resulted in a solution of 1.82 ml of I: 100,000 epinephrine. Mandibular first premolars were chosen as the experimental teeth. Upon clinical examination, all teeth were free of caries or deep restorations and had no exposed dentin. Mobility was tested with horizontal pressure using two mirror handles positioned on the buccal and lingual surfaces of the tooth. No tooth exhibited mobility greater than 0.5 mm in any direction. Periodontal probing was done on the mesial and distal aspect of each tooth. Subjects with periodontal pockets greater than 3 mm were eliminated from the study. The gingival tissue met Glickman's criteria (12) for gingival health. Electric pulp testing was performed by trained assistants using the Analytic Technology pulp tester (Analytic Technology Corp., Redmond, WA). Sensodyne toothpaste (Block Drug Inc., Jersey City, NJ) was used as an electrolyte between the pulp tester probe and the tooth. The rate of current increase was kept constant for all testing procedures and was set at 30 s to increase from no output (0) to the maximum output of 80. The pulp tester was checked with an oscilloscope to ensure proper operation. The teeth were isolated with cotton rolls, dried with air, and the probe tip was placed on the buccal surface midway between the gingival margin and the occlusal edge. Three base line readings were recorded for each experimental tooth as well as the adjacent mesial and distal teeth prior to the periodontal ligament injections. Each subject was instructed to respond when a sensation was first felt within the tooth. If the subjects felt a sensation in their gingiva, the tooth was reisolated and the pulp testing was repeated. A double-blind method was used with the randomly selected right or left mandibular premolar receiving the test solution and the contralateral premolar receiving the control solution. Random numbers were used to determine which of the test solutions would be injected at each appointment. For each subject, two cartridges of the test and control solutions were masked with opaque autoclave tape and marked with a letter A (test solution) or B (control solution). The four cartridges were then sealed in an autoclave bag which was marked with a number. The two extra cartridges served as reserves in case of cartridge breakage during the injection. Two syringes were masked with opaque autoclave tape and marked right or left. The first cartridge removed from the autoclave bag, by a trained assistant, was loaded into the right syringe and the solution letter, A or B, was recorded. One of the cartridges designated with the opposite letter was loaded into the syringe marked left. For each subject, the initial injection was given with the syringe marked right. At no time
did the assistant or doctor know which solution was being injected. Periodontal ligament injections were given with Ligmaject syringes (Healthco Inc., Boston, MA) and 30-gauge ultrashort needles (Monoject, St. Louis, MO). With the subject in a reclining position, the needle was inserted through the mesial gingival sulcus to a point of maximum penetration. The bevel of the needle was directed away from the tooth surface at approximately a 30-degree angle to the long axis of the tooth. The handle of the syringe was squeezed firmly until backpressure was achieved and this pressure was then sustained for approximately 20 s. This procedure delivered at least 0.2 ml of solution but no more than 0.3 ml for each injection. If no back-pressure was achieved, the needle was repositioned and the injection repeated. The injection was then repeated on the distal surface. The second Ligmaject syringe, loaded with one of the control or experimental solutions, was used to inject the mesial and distal surfaces of the contralateral premolar. Prior to giving the injections, each subject was instructed to rate separately the pain of the initial needle penetration and the injection of solution for all injections. The rating scale was: O-no pain; I-mild (pain which was recognizable, but not discomforting); 2-moderate (pain which was discomforting, but bearable); and 3-severe (pain which caused considerable discomfort and was difficult to bear). Each subject used their fingers to indicate the rating after needle insertion and again following injection of the solution. Immediately following the completion of each injection, an automatic timer was started. The depth of anesthesia was monitored throughout the experimental procedure by pulp testing the teeth. Complete anesthesia was defined as the absence of patient response at the maximum output of the pulp tester (an 80 reading on the 0 to 80 scale). A trained assistant tested the experimental teeth at postinjection times of 2, 4, 10, 20, 30, and 45 min. Thirty seconds after pulp testing the experimental tooth, the mesial tooth (immediately adjacent to the experimental tooth) was tested at the same basic time intervals. Sixty seconds after testing the experimental tooth, the distal tooth was tested at the same basic time intervals. The same testing procedures were repeated on the contralateral premolar and adjacent teeth. At the end of the experimental procedure, each subject was given a questionnaire. They were asked to indicate the presence, duration, and severity of any postoperative discomfort and whether the teeth felt "high" in occlusion. They were also asked to return ifany severe or unusual postoperative sequelae occurred. All subjects were recalled after 30 days. The teeth were pulp tested, the periodontium was probed for pocket depths, and the teeth were examined for mobility. Between group comparisons of the number of teeth anesthetized were made using the Fisher exact probability test. Between group comparisons of injection discomfort were made using the Mann-Whitney U test. Within group comparisons of the base line pulp test values were made using the Wilcoxon matched pairs signed rank test. A p value less than 0.05 was considered to be significant.
RESULTS Seventy-five teeth were injected with 2% lidocaine with 1:100,000 epinephrine (controls), 31 teeth received 3% me-
Periodontal Ligament Injection
Vol. 14, No.8, August 1988
pivacaine, 29 teeth .receiv~d 2% lidocaine, and 15 teeth received 1: 100,000 epmephnne. Overall, 2% lidocaine with 1: 100,000 epinephrine anesthetized 65 of 75 teeth for a 86.7% rate of successful pulpal anesthesia (Table 1).
399
The difference was statistically significant (p = 0.000). The distal tooth was anesthetized in 20.7% of the subjects with 2% lidocaine and in 75.9% of the controls (Table 1). This difference was also statistically significant (p = 0.000). Epinephrine versus the Control
Mepivacaine versus the Control (2% Lidocaine with 1:100,000 Epinephrine) When comparing 3% mepivacaine with the control solution, successful anesthesia occurred in 41.9% of the subjects injected with 3% mepivacaine, whereas 83.9% of the subjects were successfully anesthetized with the control (Table 1). The difference was statistically significant (p = 0.001). Additionally, 3% mepivacaine anesthetized 12.9% of the mesial teeth versuS 45.2% for the control (Table 1). The difference was statistically significant (p = 0.0 11). The distal tooth was anesthetized in 33.3% of the subjects with 3% mepivacaine and in 80% of the control subjects (Table 1). The difference was statistically significant (p = 0.000). Two Percent Lidocaine versus the Control Two percent lidocaine successfully anesthetized 13.8% of the subjects compared with 89.7% for the control (Table 1). This difference was statistically significant (p = 0.000). The mesial tooth was anesthetized in 6.9% of the subjects with 2% lidocaine and in 55.2% of the control subjects (Table 1). TABLE
Anesthesia versus Time Overall, the percentages of premolars successfully anesthetized with the control solution, at each time interval, were: at 2 min, 86.7%; at 4 min, 81.3%; at 10 min, 72%; at 20 min, 57.3%; at 30 min, 34.7%; and at 45 min, 17.3% (Fig. 1). Therefore, the duration of profound pulpal anesthesia (80/80 reading) was approximately 20 min with 2% lidocaine with 1: 100,000 epinephrine. When the control solution was compared with 3% mepivacaine solution, the number of premolars anesthetized at each time interval was significantly greater for the control solution through 45 min (Table 2 and Fig. 1). The duration of profound anesthesia with 3% mepivacaine
1. Anesthetic efficacy of test solutions versus control solution
Test Solution
Efficacy (%)
Tooth Premolar Mesial Distal 2% Lidocaine
41.9 (13/31)* 12.9 (4/31) 33.3 (10/30)
Tooth Premolar Mesial Distal 1:100,000 Epinephrine
13.8 (4/29) 6.9 (2/29) 20.7 (6/29)
Tooth Premolar Mesial Distal
• Number of teeth anesthetized/lotal number of teeth.
Control Solution
Efficacy (%)
p
83.9 (26/31) 45.2 (14/31) 80.0 (24/30)
0.001 0.011 0.000
89.7 (26/29) 55.2 (16/29) 75.9 (22/29)
0.000 0.000 0.000
86.7 (13/15) 26.7 (4/15) 80.0 (12/15)
0.000 0.099 0.000
2% Lidocaine with 1:100,000 epinephrine
3% Mepivacaine
-
No teeth were anesthetized with 1: 100,000 epinephrine (Table 1). Two percent lidocaine with I: 100,000 epinephrine successfully anesthetized 86.7% of the subjects, and 80% of the distal teeth (Table I). The difference was statistically significant (p = 0.000). The mesial teeth were anesthetized in 26.7% of the control subjects but this difference was not statistically significant (p = 0.099).
2% Lidocaine with 1:100,000 epinephrine
2% Lidocaine with 1:100,000 epinephrine 0.0 (0/15) 0.0 (0/15) 0.0 (0/15) Overall efficacy of 2% lidocaine with 1:100,000 epinephrine Tooth Premolar Mesial Distal
86.7 (65/75) 45.3 (34/75) 78.4 (58/74)
400
SChleder et al.
Journal of Endodontics
was approximately 4 min (Table 2). The number of mesial teeth anesthetized was greater for the control than for mepivacaine, at each time interval (Table 2). However, the differences were only significant at 2lf2 and lOlf2 min (Table 2). The control solution anesthetized more distal teeth than 3% mepivacaine at every time interval, with the differences being significant through 21 min (Table 2). The control solution anesthetized more premolars than 2% lidocaine, at all time intervals, with the difference being significant through 30 min (Table 3 and Fig. I). The duration of profound anesthesia with 2% lidocaine was 2 to 4 min (Table 3). More mesial teeth were anesthetized with the control solution, at each time interval, with the differences significant through 41h min (Table 3). More distal teeth were anesthetized through 46 minutes with the differences significant through 31 minutes (Table 3).
100 90
0-2% Lidocaine with 1'100,000 .:1.-3% Mepivacaine
i
80
D-2% Lidocaine
:l:
70
'i
:=c
When compared with 1: 100,000 epinephrine (no teeth were anesthetized with this solution), the control solution anesthetized more premolars at all time intervals. The differences were significant through 20 min (p = 0.017) (Table 4). Mesial teeth were also anesthetized with the control but the differences were not significant at any time interval (p > 0.05) (Table 4). More distal teeth were anesthetized with the control solution at each time interval. These differences were significant through 21 min (p = 0.042) (Table 4). Discomfort Ratings of Injections Table 5 shows the discomfort ratings for needle insertion and injection of solution. There were no significant differences in injection discomfort between the control and 3% mepivacaine or 2% lidocaine, except for needle insertion on the distal, which was significantly less for the control than for 2% lidocaine (Table 5). With the exception of initial needle insertion on the mesial, needle insertion and solution injection of the control were significantly less painful than injections of 1:100,000 epinephrine (Table 5). Postinjection Discomfort
~
~ 50
.. !
'0 ~
40
30
u
.f
20 10
oL~':::::::"'O----o---~~======:::::e 5
10
20
30
45
Time (minutes) FIG 1. Success and duration of 2% lidocaine with 1:100,000 epinephrine, 3% mepivacaine, and 2% lidocaine. TABLE
2. Duration of anesthesia: 3% mepivacaine versus 2% lidocaine with 1:100,00 epinephrine 2% Lidocaine with 3% Mepivacaine 1:100,000 Epinephrine (min) (Control)
One-hundred percent of the postinjection questionnaires were returned. Postinjection discomfort was experienced by 88% of the subjects for an average duration o£1.4 days (Table 6). The discomfort ranged in intensity from mild to severe and the duration ranged from 1 to 7 days (Table 7). No subjects experienced severe pain beyond day 3 or moderate pain beyond day 5 (Table 7). Thirty-seven subjects (49.3%) reported that their tooth felt high in occlusion for an average duration of 2.1 days (Table 6). At recall examination, mobility, the periodontium, and vitality tests were all within normal limits. There were no significant differences between the preinjection base line pulp test readings and the recall readings (p = 0.961). TABLE
3. Duration of anesthesia: 2% lidocaine versus 2% lidocaine with 1:100,00 epinephrine
Time Tooth Premolar
Mesial
2 4 10 20 30 45
2V2 4V2 10%
20V2 30V2 45V2 Distal
3 5 11 21 31 46
41.9% (13/31)25.8% (8/31) 9.7% (3/31) 9.7% (3/31) 3.2% (1/31) 3.2% (1/31) 6.5% (2/31) 12.9% (4/31) 0.0% (0/31) 3.2% (1/31) 0.0% (0/31) 0.0% (0/31) 30.0% (9/30) 23.3% (7/30) 10.0% (3/30) 3.3% (1/30) 3.3% (1/30) 0.0% (0/30)
83.9% (26/31) 77.4% (24/31) 74.2% (23/31) 54.8% (17/31) 41.9% (13/31) 25.8% (8/31) 45.2% (14/31) 35.5%(11/31) 29.0% (9/31) 19.4% (6/31) 16.1% (5/31) 3.2% (1/31) 76.7% (23/30) 63.3% (19/30) 53.3% (16/30) 43.3% (13/30) 23.3% (7/30) 16.7% (5/30)
• Number of teeth anesthetized/total number of teeth.
p
Tooth
0.001 0.000 0.000 0.000 0.001 0.026 0.001 0.073 0.002 0.104 0.053 0.999 0.001 0.003 0.001 0.001 0.052 0.052
Premolar
Mesial
Time (min)
2 4 10 20 30 45 2% 4% 10%
20V2
Distal
30% 45% 3 5 11 21 31 46
2% Lidocaine
2% Lidocaine with 1:100,000 Epinephrine (Control)
p
10.3% (3/29)6.9%(2/29) 0.0%(0/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29) 3.4% (1/29) 3.4% (1/29) 3.4% (1/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29) 13.8% (4/29) 6.9% (2/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29)
89.7% (26/29) 86.2% (25/29) 75.9% (22/29) 68.9% (20/29) 31.0% (9/29) 10.3% (3/29) 48.3% (14/29) 37.9% (11/29) 24.1% (7/29) 17.2% (5/29) 6.9% (2/29) 6.9% (2/29) 65.5% (19/29) 68.9% (20/29) 58.6% (17/29) 41.4% (12/29) 31.0% (9/29) 13.8% (4/29)
0.000 0.000 0.000 0.000 0.002 0.237 0.000 0.002 0.052 0.052 0.491 0.491 0.000 0.000 0.000 0.000 0.000 0.072
• Number of teeth anesthetized/total number of teeth.
V~.
14, No.8, August 1988
TABLE
4. Duration of anesthesia: 1:100,000 epinephrine versus 2% lidocaine with 1:100,00 epinephrine
Tooth
Premolar
Time (min)
2
Mesial
1:100,000 Epinephrine
0.0% (0/15)* 0.0%(0/15) 0.0% (0/15) 0.0% (0/15) 30 0.0%(0/15) 40 0.0% (0/15) 2Y2 0.0% (OilS) 4Y2 0.0% (OilS) 10Y2 0.0% (OilS) 20Y2 0.0%(0/15) 30Y2 0.0% (OilS) 45Y2 0.0% (OilS) 3 0.0% (OilS) 5 0.0% (OilS) 11 0.0% (OilS) 21 0.0% (0/15) 31 0.0% (0/15) 46 0.0% (OilS) 4 10 20
Distal
Periodontal Ligament Injection
2% Lidocaine with 1:100,000 Epinephrine (Control)
86.7% (13/15) 80.0% (12/15) 60.0% (9/15) 40.0% (6/15) 26.7% (4/15) 13.3% (2/15) 26.7% (4/15) 20.0% (3/15) 13.3% (2/15) 6.7% (1/15) 6.7% (1/15) 0.0% (0/15) 80.0% (12/15) 66.7% (10/15) 40.0% (6/15) 33.3% (5/15) 26.7% (4/15) 26.7% (4/15)
TABLE
401
5. Discomfort ratings of needle insertion and injection of solution Discomfort Ratings
p 0.000 0.000 0.001 0.017 0.099
0.483 0.099
0.244 0.483 1.000 1.000 1.000 0.000 0.000 0.017
0.042 0.099 0.099
• Number of teeth ar.esthetized{total number of teeth.
Three subjects developed herpes-like lesions after the injections (three with 2% lidocaine with epinephrine and one subject developed lesions also with 3% mepivacaine). One subject developed a hematoma of the interproximal papillae (2% lidocaine with epinephrine). All lesions resolved and the tissues were normal at the recall examinations. DISCUSSION The results of this study demonstrated that 2% lidocaine with I: 100,000 epinephrine produced significantly higher rates of successful pulpal anesthesia than 3% mepivacaine, 2% lidocaine, or 1:100,000 epinephrine. Further objective research should be done to determine whether the success rate is different in various maxillary and mandibular teeth. Various studies (13-15) have shown that carbon particles and dyes were distributed in the periapex, medullary bone, pulp, and frequently in the same tissues of adjacent teeth following the periodontal ligament injection. This seems to indicate that this injection technique is an intraosseous injection with placement of the anesthetic solution through the cribifonn plate under pressure. The primary mechanism of action does not seem to be a transient pulpal ischemia, resulting in pulpal anesthesia, as suggested by Kim (16) and by the works of Olgart and Gazelius (17) and Savoie et a1. (18). The results of our current study showed that no anesthesia was obtained with injections of epinephrine, whereas 3% mepivacaine without a vasoconstrictor produced a 41.9 % rate of successful pulpal anesthesia. Anesthesia was also obtained after intraligamentary injections of 2% lidocaine without a vasoconstrictor. These results indicated that the anesthesia produced was due primarily to the action of the anesthetic on the nerve supply, either intrapulpally or along its course before it reached the pulp. The results also show, and confinn studies by Kaufman et a1. (10) and Johnson et al. (11), that the addition of a vasoconstrictor greatly enhances the success of the periodontal ligament injection. Recently,
Solution None Mild Moderate Severe Median 2% Lidocaine with 1:100,000 epinephrine (no. 29) Insertion mesial Injection mesial Insertion distal Injection distal 2% Lidocaine (no. 29) Insertion mesial Injection mesial Insertion distal Injection distal 2% Lidocaine with 1:100,000 epinephrine (no. 31) Insertion mesial Injection mesial Insertion distal Injection distal 3% Mepivacaine (no. 31) Insertion mesial Injection mesial Insertion distal Injection distal 2% Lidocaine with 1:100,000 epinephrine (no. 15) Insertion mesial Injection mesial Insertion distal Injection distal 1:100,000 epinephrine (no. 15) Insertion mesial Injection mesial Insertion distal Injection distal
p*
9
14
4
15
10
4
o
21 23
3
3
o o
8
16
5
16
9
2
13 18
15
7
5
15
11
10
16
3
23 18
11
2
3
17
10
0.817
16
9
6
0.362
16 14
13 10
2 6
10
4
6
7
2
11 11
4 4
2
2
8
0.959
o
0.890
1
1
4
o
0.030 0.189
2
2
o o
8
o 1
0.053 0.158
o o
8
5
2
6
9 5
4
5
0.460 7
2
0.000
5
1 2
0.001 0.000
• Comparison of lest solutiOn 10 2% lidocaine with 1:100,000 epinephrine.
Handler and Albers (19) found that there were no significant differences in success or duration of the periodontal ligament injection using a solution of epinephrine alone, 2% lidocaine, or 2 % lidocaine with I :50,000 or 1: 100,000 epinephrine. They
402
Journal of Endodontics
SChleder et al. TABLE
6. Postinjection questionnaire results No. of Positive Responses
0/0
Mean Duration (days)
66 37
88.0 (66{75) 49.3 (37/75)
2.4 2.1
Postinjection pain High in occlusion
TABLE
7. Postinjection discomfort: severity and duration Day
Pain Rating No pain (%) No.* Mild pain (%) No. Moderate pain (%) No. Severe pain (%) No.
1
2
3
4
5
6
7
12.0 9 45.3 34 37.3 28 5.3 4
48.0 36 30.7 23 18.7 14 2.6 2
65.3 49 24.0 18 8.0 6 2.6 2
77.3 58 16.0 12 6.7 5
84.0 63 14.7 11 1.3 1
85.3 64 14.7 11
86.7 65 13.3 10
• Number of responses, total number-75.
defined anesthesia as values 20% above base line for three consecutive pulp test readings. Therefore, their study measured a minimum value for anesthesia. Our study measured a maximum value of 80/80 for profound anesthesia and can account for the differences between the two studies. It may be that at these minimum values of anesthesia hypoxia or pressure may be a contributing mechanism for anesthesia with this injection technique. However, anesthesia at a 20% value has not been validated clinically and probably does not have the clinical significance of no response to a pulp tester (80/80). Several authors (2, 4) have stated that the duration of anesthesia, after the periodontal ligament injection, lasted 30 to 60 min. This study found that the duration of profound pulpal anesthesia (80/80 reading) was approximately 20 min with 2 % lidocaine with I: 100,000 epinephrine. Many of the clinical studies have relied on the dentist's evaluation of the patient's pain felt during operative or surgical procedures. These clinical evaluations are more variable when compared with the objective measurement of analgesia provided by the electric pulp tester. Dreven et al. (20) have shown that an 80/ 80 reading in normal and asymptomatic teeth resulted in complete clinical analgesia. Therefore, although successful anesthesia is almost assured if the patient does not respond to the maximum output of the pulp tester in asymptomatic teeth, a reading of less than 80 but greater than base line may or may not correlate with success. This depends on the procedures (shallow cavity preparation, extraction, crown preparation, pulp extirpation) the dentist is performing and the duration of these procedures. Since 2% lidocaine with epinephrine provided a duration of 20 min, it may be better clinically to use infiltration or block injections if profound anesthesia is required for longer than 20 min. Two percent lidocaine had a duration of 2 to 4 min and was similar to the duration reported by Kaufman et al. (10). The duration for 3% mepivacaine was about 4 min. Therefore, epinephrine significantly increases the duration of anesthesia. Since the systemic effects of the periodontal ligament injection of epinephrine-containing solutions has been shown by Smith and Pashley (21), it may be prudent to use other injection tech-
niques in medically compromised patients where epinephrine is contraindicated. Onset of anesthesia was immediate (within the context of our measurement time) and corroborates the work ofprevious investigators (1, 5, 10). Basically, it was found that if the injected tooth was not anesthetized at the initial postinjection time, then anesthesia was not obtained at any subsequent pulp test interval. Anesthesia of adjacent teeth, both mesial and distal to the injected tooth, was obtained with 2% lidocaine with epinephrine, 2% lidocaine, and 3% mepivacaine. This concurs with the histological study of Smith and Walton (13). They shOWed perfusion of the pulp and surrounding bone of the injected and adjacent teeth with injected dye solutions in dogs. These results are not in agreement with Simon et al. (22) and Littner et al. (23). They reported that single tooth anesthesia could be obtained with the periodontal ligament injection and this technique could be used as an aid in endodontic diagnosis. Littner et al. (23) injected the buccal surfaces of teeth to avoid anesthesia ofadjacent teeth. Whether this limits the placement of the anesthetic solution has yet to be determined. Since the periodontal ligament injection is an intraosseous injection and the solution is deposited around adjacent teeth, it is questionable if it should be used as an aid in endodontic diagnosis. When compared with the test solutions, 2% lidocaine with epinephrine anesthetized more teeth mesial and distal to the premolars for a longer duration. Therefore, the number of adjacent teeth anesthetized and the duration of anesthesia appear to be related to the vasoconstrictor. More distal teeth than mesial teeth were anesthetized with all solutions (except epinephrine alone). Kaufman et al. (5) found that teeth with longer roots were more difficult to anesthetize, specifically canines. This may possibly explain our findings since the anesthetic solution would have to travel a longer distance for the mesial teeth (canines). Birn (24) observed that perforations in the wall of the cribiform plate increased in the mandible from the incisors toward the molar. This could allow for placement of the anesthetic solution distally more readily than mesially. More research is needed to determine the exact pattern of anesthetic solution deposition related to adjacent teeth. For all solutions, needle insertion on the mesial was rated as mild pain (median of 1, Table 5) and indicated that patients did not generally find this initial needle insertion to be very painful. Distal needle insertion pain was rated as no pain (median of 0, Table 5) for the 2% lidocaine solution with epinephrine. This may be related to patients acceptance of the procedure or anesthesia of the soft tissues from the mesial injection. The statistically significant difference between 2% lidocaine with epinephrine and 2% lidocaine on distal needle insertion was probably related to the lower success rate of anesthesia with 2% lidocaine. The same was probably true for the difference between 2% lidocaine with epinephrine and the epinephrine solution (Table 6). Pain of injection (mesial and distal) for the anesthetic solutions was rated none to mild pain (median 0 to 1, Table 5) and indicated that patients did not generally find injection of the solutions very painful. Injection pain was rated moderately painful (median of 2, Table 5) for both the mesial and distal injections of epinephrine. Since epinephrine produced no anesthesia, the injections caused considerably more discomfort when compared with the 2%
.Vol. 14, No.8, August 1988
lidocaine with epinephrine. Further research should be done to determine if needle insertion and solution injection pain is different in maxillary and mandibular teeth and in different pathological conditions of the pulp. postinjection discomfort was experienced by 88% of the subjects on day 1. These results do not agree with some authors (2, 5) who reported few complaints of postoperative discomfort in clinical studies. Other authors (8, 10, II) have reported postinjection pain with this technique. The high potential for postoperative discomfort must be considered when using this technique clinically. Forty-nine percent of the subjects reported that at least one of the injected teeth felt high in occlusion. Although the occlusion was not checked clinically, it is doubtful that the teeth were actually in hyperocclusion. Most likely the teeth were sore to chewing and this may have accounted for the response that the teeth felt high. This is supported by the results that the mean duration of feeling high in occlusion, 2.1 days, was close to the mean duration of postinjection discomfort, 2.4 days. The development of herpes-like lesions and hematoma formation showed that these complications can arise following the periodontal ligament injection but the numbers were very small overall. Since all lesions resolved without sequelae, they cannot be considered serious. Faulkner (8) reported five patients had acute complications following intraligamentary injections. All resolved with antibiotic treatment or mouthwashes. Therefore, there may be a small risk of complications associated with the use of this injection technique, but this has to be considered a rare occurrence. The follow-up examinations showed that all pulps and the periodontium were within normal limits after 30 days. This corroborates previous clinical (4, 5, 8-10) and animal studies (14, 25-28) that damage was minimal and this injection technique was safe to the pulp and periodontium of clinically normal, healthy teeth. However, more research is needed to determine the effects on periodontally involved teeth and teeth with compromised pulps. CONCLUSIONS Concerning the use of the periodontal ligament injection as a primary anesthetic technique in human mandibular premolars, the following conclusions were reached: The periodontal ligament injection using 2% lidocaine with 1: 100,000 epinephrine was an effective technique for anesthetizing mandibular first premolars. However, the duration of profound pulpal anesthesia was approximately 20 min. Periodontal ligament injections of the mandibular first premolar, using 2% lidocaine with 1: 100,000 epinephrine, can anesthetize adjacent mesial and distal teeth. The periodontal ligament injection using 3% mepivacaine was effective in less than 50% of the teeth and had a duration of approximately 4 min. The periodontal ligament injection using 2% lidocaine anesthetized only 14 % of the teeth and had a duration of approximately 2 to 4 min. The periodontal ligament injection using a solution of 1:100,000 epinephrine alone was completely ineffective for anesthesia. The addition of epinephrine to 2% lidocaine increased the
Periodontal Ligament Injection
403
success and duration of anesthesia. Initial needle penetration and injection of 2% lidocaine with epinephrine, in clinically healthy teeth, were only mildly discomforting. Postinjection discomfort was experienced by the majority of the subjects (88%). The average duration was 2.4 days. Almost 50% of the subjects reported that their tooth felt high in occlusion for an average duration of 2.1 days. No clinically observable pulpal or periodontal damage was seen at 4 wk postinjection. This study was supported by research funding from the Ohio Association of Endondontists, J. David Brilliant Memorial Fund. This article was adapted from a thesis submitted by Dr. Schleder in partial fulfillment of the requirements for the MS degree at The Ohio State University, Columbus, OH. A portion of this article was presented at the 42nd Annual Session of the American Association of Endodontists, San Diego, CA, and was honored by a graduate student research award. Dr. Schleder is in private practice limited to endodontics, Willoughby, OH. Dr. Reader is associate professor, Department of Endodontics, College of Dentistry, The Ohio State University, Columbus, OH. Dr. Beck is associate professor, Department of Diagnostic Services, The Ohio State University. Dr. Meyers is professor and chairman, Department of Endodontics, The Ohio State University. Address requests for reprints to Dr. Reader, Department of Endodontics, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH 43210.
References 1. Walton RE, Abbott BJ. Periodontal ligament injection: a clinical evaluation. J Am Dent Assoc 1981;103:571-5. 2. Malamed SF. The periodontal ligament (PDL) injection: an alternative to the inferior alveolar block. Oral Surg 1982;53:117-21. 3. Montagnese TA, Reader A, Melfi R. A comparative study of the GowGates technique and a standard technique for mandibular anesthesia. J Endodon 1984;10:158-63. 4. Khedari AJ. Alternative to mandibular block injections through interligamentary anesthesia. Quintessence Int 1982;2:231-7. 5. Kaufman E, Galili D, Garfunkel AA. Intraligamentary anesthesia: a clinical study. J Prosthet Dent 1983;49:337-9. 6. Grainger JK. Intraligamentary anesthesia. Dent Anaesth Sed 1982;11 :45-9. 7. Council on Dental Materials, Instruments and Equipment. Status report: the periodontal ligament injection. J Am Dent Assoc 1983;106:222-4. 8. Faulkner RK. The high pressure periodontal ligament injection. Br Dent J 1983;154:103-5. 9. Smith NG, Walton RE, Abbott BJ. Clinical evaluation of periodontal ligament anesthesia using a pressure syringe. J Am Dent Assoc 1983;107:953-
6. 10. Kaufman E, LeResche L, Sommers E, Dworkin S, Truelove E. Intraligamentary anesthesia: a double-blind comparative study. J Am Dent Assoc 1984;108:175-8. 11. Johnson GK, Hlava GL, Kalkwarf KL. A comparison of periodontal intraligamentary anesthesia using etidocaine HCI and lidocaine HCI. Anesth Prog 1985;9/10:202-5. 12. Glickman I. Clinical periodontology. Philadelphia: WB Saunders, 1972:36-7. 13. Smith GN, Walton RE. Periodontal ligament injection: distribution of injected solutions. Oral Surg 1983;55:232-7. 14. Fuhs MQ, Walker WA, Gough RW, Schindler WG, Hartman KS. The periodontal ligament injection: histological effects on the periodontium in dogs. J Endodon 1983;9:411-5. 15. Dreyer WP, van Heerden JD, Joubert JJ. The route of periodontal ligament injection of local anesthetic solution. J Endodon 1983;9:471-4. 16. Kim S. Ligamental injection: a physiological explanation of its efficacy. J Endodon 1986;12:486-91. 17. Olgart L, Gazelius B. Effects of adrenalin and falypressin (octapressin) on blood flow and sensory nerve activity in the tooth. Acta Odont Scand 1977;35:67-75. 18. Savoie SS, LeMay H, Taleb L. The effect of epinephrine on pulp microcirculation. J Dent Res 1979;58:2074-9. 19. Handler LE and Albers DD. The effects of vasoconstrictor epinephrine on the duration of pulpal anesthesia using the intraligamentary injection. J Am Dent Assoc 1987;114:807-9. 20. Dreven LJ, Reader A, Beck FM, Meyers WJ, Weaver J. An evaluation
404
Schleder et al.
of an electric pulp tester as a measure of analgesia in human vital teeth. J Endodon 1987;13:233-8. 21. Smith NG, Pashley DH. Periodontal ligament injection: evaluation of systemic effects. Oral Surg 1983;56:571-4. 22. Simon DE III, Jacobs LT, Senia ES, Walker WA III. Intraligamentary anesthesia as an aid in endodontic diagnosis. Oral Surg 1982;54:n-8. 23. Littner MM, Tamse A, Kaffe I. A new technique of selective anestihesia for diagnosing acute pulpitis in tihe mandible. J Endodon 1983;9:116-9. 24. Bim H. The vascular supply of the periodontal membrane. J Periodont
Journal of Endodontics Res 1966;1:51-68. 25. Brannstrom M. Nordenvall KJ. Hedstrom KG. Periodontal tissue changes after intraligamentary anesthesia. J Dent Child 1982;49:417-23. 26. Walton RE, Gamick JJ. The periodontal ligament in;ection: histologic effects on the periodontium in monkey. J Endodon 1982;8:22-6. 27. Peurach JC. Pulpal response to intraligamentary anesthesia in the cynomologus monkey. Anesth Prog 1985;3/4:73-5. 28. Lin L, Lapeyrolerie M, Skribner J, ShovUn F. Periodontal ligament injection: effects on pulp tissue. J Endodon 1985;11 :529-34.
Printed in U.S.A. VOL. 14,No.8,AUGUST1988
Copyright C> 1988 by The American Association of Endodontists
CLINICAL ARTICLES The Periodontal Ligament Injection: A Comparison of 2% Lidocaine, 3% Mepivacaine, and 1:100,000 Epinephrine to 20/0 Lidocaine with 1:100,000 Epinephrine in Human Mandibular Premolars John Richard Schleder, DDS, MS, AI Reader, DDS, MS, Mike Beck, DDS, MA, and William J. Meyers, DMD, MEd
gamentary anesthesia has been advocated as a primary and a supplemental injection technique (I, 2, 4-10). Overall success rates reported for this injection technique, in clinical studies (1,2,4, 8,9), have ranged from 81 to 86% when used as a primary injection, and from 83 to 92% when used for supplemental anesthesia. Three studies (2, 10, 11) have compared the use of different anesthetic solutions with the periodontal ligament injection. Malamed (2) reported success rates of74 and 84% for different anesthetics when periodontal ligament injections were given as the primary injection technique for patients undergoing routine dental procedures. The number of injections were too small to show any significant differences in efficacy or duration of the solutions. Kaufman et al. (10) and Johnson et al. (II) demonstrated that the duration of pulpal and soft tissue anesthesia, produced by periodontal ligament injections, was related to the solution used and specifically to the concentration of the vasoconstrictor. Therefore, there is little comparative information on the efficacy or duration of various anesthetic solutions used with this injection technique. The purpose of this study was to evaluate the anesthetic efficacy of the periodontal ligament injection by comparing three solutions, 2% lidocaine, 3% rnepivacaine, and 1: 100,000 epinephrine with 2% lidocaine with I: 100,00 epinephrine. Human mandibular premolars were tested for anesthesia by using an electric pulp tester.
The purpose of this study was to evaluate, with an electric pulp tester, the anesthetic efficacy of the periodontal ligament injection. Two percent lidocaine, 3% mepivacaine, and 1:100,000 epinephrine were compared with 2% lidocaine with 1:100,000 epinephrine in human mandibular premolars. Two percent lidocaine with 1:100,000 epinephrine anesthetized significantly more first premolars (87% success), for a longer duration (approximately 20 min), than any of the test solutions. Three percent mepivacaine anesthetized 42% of the teeth and had a duration of approximately 4 min. Two percent lidocaine anesthetized 14% of the teeth and had a duration of 2 to 4 min. The epinephrine solution did not anesthetize any teeth. Two percent lidocaine with epinephrine anesthetized more adjacent teeth, both mesial (45% success rate) and distal (78% success rate), for a longer duration than any of the test solutions. Initial needle penetrations and injections of 2% lidocaine with epinephrine, in clinically healthy teeth, were only mildly discomforting. Postinjection discomfort was experienced by 88% of the SUbjects and 49% reported that their tooth felt high in occlusion. No clinically observable pulpal or periodontal damage was seen at 4 wk postinjection.
MATERIALS AND METHODS Seventy-five dental and dental hygiene students, 40 males and 35 females ranging in age from 20 to 31 yr, participated in this study. Based on a clinical written history and oral questioning, the subjects were judged to be in good health, were currently taking no medication, and had never had an allergic or toxic reaction to a local anesthetic agent. The study was approved by the Human Subjects Committee at The Ohio State University and written consent was obtained from each subject.
Local anesthesia is the primary method used in dentistry to control patients' pain. However, even in the presence of adequate soft tissue anesthesia, there may be incomplete pulpal anesthesia (1,2). This is particularly true in the mandible where obtaining profound pulpal anesthesia may be difficult (1-3). Recently, the periodontal ligament injection has received much attention in the dental literature (I, 2, 4-10). Intrali397
398
Journal of Endodontics
SChleder et al.
The experimental solutions tested were 2% lidocaine (Astra Pharmaceuticals Products, Inc., Worchester, MA), 3% mepivacaine (Cook-Waite Lab. Inc., New York, NY), and I: 100,000 epinephrine (Elkins-Senn, Inc., Cherry Hill, NJ). These solutions were compared with the control solution, 2% lidocaine with I: 100,000 epinephrine (Astra Pharmaceuticals). The epinephrine solution was prepared in the following manner. Empty anesthetic cartridges and plungers were washed for 5 min with soap and water using a nylon brush. All cartridges and plungers were then rinsed in two changes of distilled water for I min and autoclaved for 50 min. Using a sterile technique, cartridges were filled with 1.8 ml of sterile saline and 18.0 ~l of I: I,000 epinephrine using a Hamilton microliter syringe (Hamilton Co., Reno, NY). This resulted in a solution of 1.82 ml of I: 100,000 epinephrine. Mandibular first premolars were chosen as the experimental teeth. Upon clinical examination, all teeth were free of caries or deep restorations and had no exposed dentin. Mobility was tested with horizontal pressure using two mirror handles positioned on the buccal and lingual surfaces of the tooth. No tooth exhibited mobility greater than 0.5 mm in any direction. Periodontal probing was done on the mesial and distal aspect of each tooth. Subjects with periodontal pockets greater than 3 mm were eliminated from the study. The gingival tissue met Glickman's criteria (12) for gingival health. Electric pulp testing was performed by trained assistants using the Analytic Technology pulp tester (Analytic Technology Corp., Redmond, WA). Sensodyne toothpaste (Block Drug Inc., Jersey City, NJ) was used as an electrolyte between the pulp tester probe and the tooth. The rate of current increase was kept constant for all testing procedures and was set at 30 s to increase from no output (0) to the maximum output of 80. The pulp tester was checked with an oscilloscope to ensure proper operation. The teeth were isolated with cotton rolls, dried with air, and the probe tip was placed on the buccal surface midway between the gingival margin and the occlusal edge. Three base line readings were recorded for each experimental tooth as well as the adjacent mesial and distal teeth prior to the periodontal ligament injections. Each subject was instructed to respond when a sensation was first felt within the tooth. If the subjects felt a sensation in their gingiva, the tooth was reisolated and the pulp testing was repeated. A double-blind method was used with the randomly selected right or left mandibular premolar receiving the test solution and the contralateral premolar receiving the control solution. Random numbers were used to determine which of the test solutions would be injected at each appointment. For each subject, two cartridges of the test and control solutions were masked with opaque autoclave tape and marked with a letter A (test solution) or B (control solution). The four cartridges were then sealed in an autoclave bag which was marked with a number. The two extra cartridges served as reserves in case of cartridge breakage during the injection. Two syringes were masked with opaque autoclave tape and marked right or left. The first cartridge removed from the autoclave bag, by a trained assistant, was loaded into the right syringe and the solution letter, A or B, was recorded. One of the cartridges designated with the opposite letter was loaded into the syringe marked left. For each subject, the initial injection was given with the syringe marked right. At no time
did the assistant or doctor know which solution was being injected. Periodontal ligament injections were given with Ligmaject syringes (Healthco Inc., Boston, MA) and 30-gauge ultrashort needles (Monoject, St. Louis, MO). With the subject in a reclining position, the needle was inserted through the mesial gingival sulcus to a point of maximum penetration. The bevel of the needle was directed away from the tooth surface at approximately a 30-degree angle to the long axis of the tooth. The handle of the syringe was squeezed firmly until backpressure was achieved and this pressure was then sustained for approximately 20 s. This procedure delivered at least 0.2 ml of solution but no more than 0.3 ml for each injection. If no back-pressure was achieved, the needle was repositioned and the injection repeated. The injection was then repeated on the distal surface. The second Ligmaject syringe, loaded with one of the control or experimental solutions, was used to inject the mesial and distal surfaces of the contralateral premolar. Prior to giving the injections, each subject was instructed to rate separately the pain of the initial needle penetration and the injection of solution for all injections. The rating scale was: O-no pain; I-mild (pain which was recognizable, but not discomforting); 2-moderate (pain which was discomforting, but bearable); and 3-severe (pain which caused considerable discomfort and was difficult to bear). Each subject used their fingers to indicate the rating after needle insertion and again following injection of the solution. Immediately following the completion of each injection, an automatic timer was started. The depth of anesthesia was monitored throughout the experimental procedure by pulp testing the teeth. Complete anesthesia was defined as the absence of patient response at the maximum output of the pulp tester (an 80 reading on the 0 to 80 scale). A trained assistant tested the experimental teeth at postinjection times of 2, 4, 10, 20, 30, and 45 min. Thirty seconds after pulp testing the experimental tooth, the mesial tooth (immediately adjacent to the experimental tooth) was tested at the same basic time intervals. Sixty seconds after testing the experimental tooth, the distal tooth was tested at the same basic time intervals. The same testing procedures were repeated on the contralateral premolar and adjacent teeth. At the end of the experimental procedure, each subject was given a questionnaire. They were asked to indicate the presence, duration, and severity of any postoperative discomfort and whether the teeth felt "high" in occlusion. They were also asked to return ifany severe or unusual postoperative sequelae occurred. All subjects were recalled after 30 days. The teeth were pulp tested, the periodontium was probed for pocket depths, and the teeth were examined for mobility. Between group comparisons of the number of teeth anesthetized were made using the Fisher exact probability test. Between group comparisons of injection discomfort were made using the Mann-Whitney U test. Within group comparisons of the base line pulp test values were made using the Wilcoxon matched pairs signed rank test. A p value less than 0.05 was considered to be significant.
RESULTS Seventy-five teeth were injected with 2% lidocaine with 1:100,000 epinephrine (controls), 31 teeth received 3% me-
Periodontal Ligament Injection
Vol. 14, No.8, August 1988
pivacaine, 29 teeth .receiv~d 2% lidocaine, and 15 teeth received 1: 100,000 epmephnne. Overall, 2% lidocaine with 1: 100,000 epinephrine anesthetized 65 of 75 teeth for a 86.7% rate of successful pulpal anesthesia (Table 1).
399
The difference was statistically significant (p = 0.000). The distal tooth was anesthetized in 20.7% of the subjects with 2% lidocaine and in 75.9% of the controls (Table 1). This difference was also statistically significant (p = 0.000). Epinephrine versus the Control
Mepivacaine versus the Control (2% Lidocaine with 1:100,000 Epinephrine) When comparing 3% mepivacaine with the control solution, successful anesthesia occurred in 41.9% of the subjects injected with 3% mepivacaine, whereas 83.9% of the subjects were successfully anesthetized with the control (Table 1). The difference was statistically significant (p = 0.001). Additionally, 3% mepivacaine anesthetized 12.9% of the mesial teeth versuS 45.2% for the control (Table 1). The difference was statistically significant (p = 0.0 11). The distal tooth was anesthetized in 33.3% of the subjects with 3% mepivacaine and in 80% of the control subjects (Table 1). The difference was statistically significant (p = 0.000). Two Percent Lidocaine versus the Control Two percent lidocaine successfully anesthetized 13.8% of the subjects compared with 89.7% for the control (Table 1). This difference was statistically significant (p = 0.000). The mesial tooth was anesthetized in 6.9% of the subjects with 2% lidocaine and in 55.2% of the control subjects (Table 1). TABLE
Anesthesia versus Time Overall, the percentages of premolars successfully anesthetized with the control solution, at each time interval, were: at 2 min, 86.7%; at 4 min, 81.3%; at 10 min, 72%; at 20 min, 57.3%; at 30 min, 34.7%; and at 45 min, 17.3% (Fig. 1). Therefore, the duration of profound pulpal anesthesia (80/80 reading) was approximately 20 min with 2% lidocaine with 1: 100,000 epinephrine. When the control solution was compared with 3% mepivacaine solution, the number of premolars anesthetized at each time interval was significantly greater for the control solution through 45 min (Table 2 and Fig. 1). The duration of profound anesthesia with 3% mepivacaine
1. Anesthetic efficacy of test solutions versus control solution
Test Solution
Efficacy (%)
Tooth Premolar Mesial Distal 2% Lidocaine
41.9 (13/31)* 12.9 (4/31) 33.3 (10/30)
Tooth Premolar Mesial Distal 1:100,000 Epinephrine
13.8 (4/29) 6.9 (2/29) 20.7 (6/29)
Tooth Premolar Mesial Distal
• Number of teeth anesthetized/lotal number of teeth.
Control Solution
Efficacy (%)
p
83.9 (26/31) 45.2 (14/31) 80.0 (24/30)
0.001 0.011 0.000
89.7 (26/29) 55.2 (16/29) 75.9 (22/29)
0.000 0.000 0.000
86.7 (13/15) 26.7 (4/15) 80.0 (12/15)
0.000 0.099 0.000
2% Lidocaine with 1:100,000 epinephrine
3% Mepivacaine
-
No teeth were anesthetized with 1: 100,000 epinephrine (Table 1). Two percent lidocaine with I: 100,000 epinephrine successfully anesthetized 86.7% of the subjects, and 80% of the distal teeth (Table I). The difference was statistically significant (p = 0.000). The mesial teeth were anesthetized in 26.7% of the control subjects but this difference was not statistically significant (p = 0.099).
2% Lidocaine with 1:100,000 epinephrine
2% Lidocaine with 1:100,000 epinephrine 0.0 (0/15) 0.0 (0/15) 0.0 (0/15) Overall efficacy of 2% lidocaine with 1:100,000 epinephrine Tooth Premolar Mesial Distal
86.7 (65/75) 45.3 (34/75) 78.4 (58/74)
400
SChleder et al.
Journal of Endodontics
was approximately 4 min (Table 2). The number of mesial teeth anesthetized was greater for the control than for mepivacaine, at each time interval (Table 2). However, the differences were only significant at 2lf2 and lOlf2 min (Table 2). The control solution anesthetized more distal teeth than 3% mepivacaine at every time interval, with the differences being significant through 21 min (Table 2). The control solution anesthetized more premolars than 2% lidocaine, at all time intervals, with the difference being significant through 30 min (Table 3 and Fig. I). The duration of profound anesthesia with 2% lidocaine was 2 to 4 min (Table 3). More mesial teeth were anesthetized with the control solution, at each time interval, with the differences significant through 41h min (Table 3). More distal teeth were anesthetized through 46 minutes with the differences significant through 31 minutes (Table 3).
100 90
0-2% Lidocaine with 1'100,000 .:1.-3% Mepivacaine
i
80
D-2% Lidocaine
:l:
70
'i
:=c
When compared with 1: 100,000 epinephrine (no teeth were anesthetized with this solution), the control solution anesthetized more premolars at all time intervals. The differences were significant through 20 min (p = 0.017) (Table 4). Mesial teeth were also anesthetized with the control but the differences were not significant at any time interval (p > 0.05) (Table 4). More distal teeth were anesthetized with the control solution at each time interval. These differences were significant through 21 min (p = 0.042) (Table 4). Discomfort Ratings of Injections Table 5 shows the discomfort ratings for needle insertion and injection of solution. There were no significant differences in injection discomfort between the control and 3% mepivacaine or 2% lidocaine, except for needle insertion on the distal, which was significantly less for the control than for 2% lidocaine (Table 5). With the exception of initial needle insertion on the mesial, needle insertion and solution injection of the control were significantly less painful than injections of 1:100,000 epinephrine (Table 5). Postinjection Discomfort
~
~ 50
.. !
'0 ~
40
30
u
.f
20 10
oL~':::::::"'O----o---~~======:::::e 5
10
20
30
45
Time (minutes) FIG 1. Success and duration of 2% lidocaine with 1:100,000 epinephrine, 3% mepivacaine, and 2% lidocaine. TABLE
2. Duration of anesthesia: 3% mepivacaine versus 2% lidocaine with 1:100,00 epinephrine 2% Lidocaine with 3% Mepivacaine 1:100,000 Epinephrine (min) (Control)
One-hundred percent of the postinjection questionnaires were returned. Postinjection discomfort was experienced by 88% of the subjects for an average duration o£1.4 days (Table 6). The discomfort ranged in intensity from mild to severe and the duration ranged from 1 to 7 days (Table 7). No subjects experienced severe pain beyond day 3 or moderate pain beyond day 5 (Table 7). Thirty-seven subjects (49.3%) reported that their tooth felt high in occlusion for an average duration of 2.1 days (Table 6). At recall examination, mobility, the periodontium, and vitality tests were all within normal limits. There were no significant differences between the preinjection base line pulp test readings and the recall readings (p = 0.961). TABLE
3. Duration of anesthesia: 2% lidocaine versus 2% lidocaine with 1:100,00 epinephrine
Time Tooth Premolar
Mesial
2 4 10 20 30 45
2V2 4V2 10%
20V2 30V2 45V2 Distal
3 5 11 21 31 46
41.9% (13/31)25.8% (8/31) 9.7% (3/31) 9.7% (3/31) 3.2% (1/31) 3.2% (1/31) 6.5% (2/31) 12.9% (4/31) 0.0% (0/31) 3.2% (1/31) 0.0% (0/31) 0.0% (0/31) 30.0% (9/30) 23.3% (7/30) 10.0% (3/30) 3.3% (1/30) 3.3% (1/30) 0.0% (0/30)
83.9% (26/31) 77.4% (24/31) 74.2% (23/31) 54.8% (17/31) 41.9% (13/31) 25.8% (8/31) 45.2% (14/31) 35.5%(11/31) 29.0% (9/31) 19.4% (6/31) 16.1% (5/31) 3.2% (1/31) 76.7% (23/30) 63.3% (19/30) 53.3% (16/30) 43.3% (13/30) 23.3% (7/30) 16.7% (5/30)
• Number of teeth anesthetized/total number of teeth.
p
Tooth
0.001 0.000 0.000 0.000 0.001 0.026 0.001 0.073 0.002 0.104 0.053 0.999 0.001 0.003 0.001 0.001 0.052 0.052
Premolar
Mesial
Time (min)
2 4 10 20 30 45 2% 4% 10%
20V2
Distal
30% 45% 3 5 11 21 31 46
2% Lidocaine
2% Lidocaine with 1:100,000 Epinephrine (Control)
p
10.3% (3/29)6.9%(2/29) 0.0%(0/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29) 3.4% (1/29) 3.4% (1/29) 3.4% (1/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29) 13.8% (4/29) 6.9% (2/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29) 0.0% (0/29)
89.7% (26/29) 86.2% (25/29) 75.9% (22/29) 68.9% (20/29) 31.0% (9/29) 10.3% (3/29) 48.3% (14/29) 37.9% (11/29) 24.1% (7/29) 17.2% (5/29) 6.9% (2/29) 6.9% (2/29) 65.5% (19/29) 68.9% (20/29) 58.6% (17/29) 41.4% (12/29) 31.0% (9/29) 13.8% (4/29)
0.000 0.000 0.000 0.000 0.002 0.237 0.000 0.002 0.052 0.052 0.491 0.491 0.000 0.000 0.000 0.000 0.000 0.072
• Number of teeth anesthetized/total number of teeth.
V~.
14, No.8, August 1988
TABLE
4. Duration of anesthesia: 1:100,000 epinephrine versus 2% lidocaine with 1:100,00 epinephrine
Tooth
Premolar
Time (min)
2
Mesial
1:100,000 Epinephrine
0.0% (0/15)* 0.0%(0/15) 0.0% (0/15) 0.0% (0/15) 30 0.0%(0/15) 40 0.0% (0/15) 2Y2 0.0% (OilS) 4Y2 0.0% (OilS) 10Y2 0.0% (OilS) 20Y2 0.0%(0/15) 30Y2 0.0% (OilS) 45Y2 0.0% (OilS) 3 0.0% (OilS) 5 0.0% (OilS) 11 0.0% (OilS) 21 0.0% (0/15) 31 0.0% (0/15) 46 0.0% (OilS) 4 10 20
Distal
Periodontal Ligament Injection
2% Lidocaine with 1:100,000 Epinephrine (Control)
86.7% (13/15) 80.0% (12/15) 60.0% (9/15) 40.0% (6/15) 26.7% (4/15) 13.3% (2/15) 26.7% (4/15) 20.0% (3/15) 13.3% (2/15) 6.7% (1/15) 6.7% (1/15) 0.0% (0/15) 80.0% (12/15) 66.7% (10/15) 40.0% (6/15) 33.3% (5/15) 26.7% (4/15) 26.7% (4/15)
TABLE
401
5. Discomfort ratings of needle insertion and injection of solution Discomfort Ratings
p 0.000 0.000 0.001 0.017 0.099
0.483 0.099
0.244 0.483 1.000 1.000 1.000 0.000 0.000 0.017
0.042 0.099 0.099
• Number of teeth ar.esthetized{total number of teeth.
Three subjects developed herpes-like lesions after the injections (three with 2% lidocaine with epinephrine and one subject developed lesions also with 3% mepivacaine). One subject developed a hematoma of the interproximal papillae (2% lidocaine with epinephrine). All lesions resolved and the tissues were normal at the recall examinations. DISCUSSION The results of this study demonstrated that 2% lidocaine with I: 100,000 epinephrine produced significantly higher rates of successful pulpal anesthesia than 3% mepivacaine, 2% lidocaine, or 1:100,000 epinephrine. Further objective research should be done to determine whether the success rate is different in various maxillary and mandibular teeth. Various studies (13-15) have shown that carbon particles and dyes were distributed in the periapex, medullary bone, pulp, and frequently in the same tissues of adjacent teeth following the periodontal ligament injection. This seems to indicate that this injection technique is an intraosseous injection with placement of the anesthetic solution through the cribifonn plate under pressure. The primary mechanism of action does not seem to be a transient pulpal ischemia, resulting in pulpal anesthesia, as suggested by Kim (16) and by the works of Olgart and Gazelius (17) and Savoie et a1. (18). The results of our current study showed that no anesthesia was obtained with injections of epinephrine, whereas 3% mepivacaine without a vasoconstrictor produced a 41.9 % rate of successful pulpal anesthesia. Anesthesia was also obtained after intraligamentary injections of 2% lidocaine without a vasoconstrictor. These results indicated that the anesthesia produced was due primarily to the action of the anesthetic on the nerve supply, either intrapulpally or along its course before it reached the pulp. The results also show, and confinn studies by Kaufman et a1. (10) and Johnson et al. (11), that the addition of a vasoconstrictor greatly enhances the success of the periodontal ligament injection. Recently,
Solution None Mild Moderate Severe Median 2% Lidocaine with 1:100,000 epinephrine (no. 29) Insertion mesial Injection mesial Insertion distal Injection distal 2% Lidocaine (no. 29) Insertion mesial Injection mesial Insertion distal Injection distal 2% Lidocaine with 1:100,000 epinephrine (no. 31) Insertion mesial Injection mesial Insertion distal Injection distal 3% Mepivacaine (no. 31) Insertion mesial Injection mesial Insertion distal Injection distal 2% Lidocaine with 1:100,000 epinephrine (no. 15) Insertion mesial Injection mesial Insertion distal Injection distal 1:100,000 epinephrine (no. 15) Insertion mesial Injection mesial Insertion distal Injection distal
p*
9
14
4
15
10
4
o
21 23
3
3
o o
8
16
5
16
9
2
13 18
15
7
5
15
11
10
16
3
23 18
11
2
3
17
10
0.817
16
9
6
0.362
16 14
13 10
2 6
10
4
6
7
2
11 11
4 4
2
2
8
0.959
o
0.890
1
1
4
o
0.030 0.189
2
2
o o
8
o 1
0.053 0.158
o o
8
5
2
6
9 5
4
5
0.460 7
2
0.000
5
1 2
0.001 0.000
• Comparison of lest solutiOn 10 2% lidocaine with 1:100,000 epinephrine.
Handler and Albers (19) found that there were no significant differences in success or duration of the periodontal ligament injection using a solution of epinephrine alone, 2% lidocaine, or 2 % lidocaine with I :50,000 or 1: 100,000 epinephrine. They
402
Journal of Endodontics
SChleder et al. TABLE
6. Postinjection questionnaire results No. of Positive Responses
0/0
Mean Duration (days)
66 37
88.0 (66{75) 49.3 (37/75)
2.4 2.1
Postinjection pain High in occlusion
TABLE
7. Postinjection discomfort: severity and duration Day
Pain Rating No pain (%) No.* Mild pain (%) No. Moderate pain (%) No. Severe pain (%) No.
1
2
3
4
5
6
7
12.0 9 45.3 34 37.3 28 5.3 4
48.0 36 30.7 23 18.7 14 2.6 2
65.3 49 24.0 18 8.0 6 2.6 2
77.3 58 16.0 12 6.7 5
84.0 63 14.7 11 1.3 1
85.3 64 14.7 11
86.7 65 13.3 10
• Number of responses, total number-75.
defined anesthesia as values 20% above base line for three consecutive pulp test readings. Therefore, their study measured a minimum value for anesthesia. Our study measured a maximum value of 80/80 for profound anesthesia and can account for the differences between the two studies. It may be that at these minimum values of anesthesia hypoxia or pressure may be a contributing mechanism for anesthesia with this injection technique. However, anesthesia at a 20% value has not been validated clinically and probably does not have the clinical significance of no response to a pulp tester (80/80). Several authors (2, 4) have stated that the duration of anesthesia, after the periodontal ligament injection, lasted 30 to 60 min. This study found that the duration of profound pulpal anesthesia (80/80 reading) was approximately 20 min with 2 % lidocaine with I: 100,000 epinephrine. Many of the clinical studies have relied on the dentist's evaluation of the patient's pain felt during operative or surgical procedures. These clinical evaluations are more variable when compared with the objective measurement of analgesia provided by the electric pulp tester. Dreven et al. (20) have shown that an 80/ 80 reading in normal and asymptomatic teeth resulted in complete clinical analgesia. Therefore, although successful anesthesia is almost assured if the patient does not respond to the maximum output of the pulp tester in asymptomatic teeth, a reading of less than 80 but greater than base line may or may not correlate with success. This depends on the procedures (shallow cavity preparation, extraction, crown preparation, pulp extirpation) the dentist is performing and the duration of these procedures. Since 2% lidocaine with epinephrine provided a duration of 20 min, it may be better clinically to use infiltration or block injections if profound anesthesia is required for longer than 20 min. Two percent lidocaine had a duration of 2 to 4 min and was similar to the duration reported by Kaufman et al. (10). The duration for 3% mepivacaine was about 4 min. Therefore, epinephrine significantly increases the duration of anesthesia. Since the systemic effects of the periodontal ligament injection of epinephrine-containing solutions has been shown by Smith and Pashley (21), it may be prudent to use other injection tech-
niques in medically compromised patients where epinephrine is contraindicated. Onset of anesthesia was immediate (within the context of our measurement time) and corroborates the work ofprevious investigators (1, 5, 10). Basically, it was found that if the injected tooth was not anesthetized at the initial postinjection time, then anesthesia was not obtained at any subsequent pulp test interval. Anesthesia of adjacent teeth, both mesial and distal to the injected tooth, was obtained with 2% lidocaine with epinephrine, 2% lidocaine, and 3% mepivacaine. This concurs with the histological study of Smith and Walton (13). They shOWed perfusion of the pulp and surrounding bone of the injected and adjacent teeth with injected dye solutions in dogs. These results are not in agreement with Simon et al. (22) and Littner et al. (23). They reported that single tooth anesthesia could be obtained with the periodontal ligament injection and this technique could be used as an aid in endodontic diagnosis. Littner et al. (23) injected the buccal surfaces of teeth to avoid anesthesia ofadjacent teeth. Whether this limits the placement of the anesthetic solution has yet to be determined. Since the periodontal ligament injection is an intraosseous injection and the solution is deposited around adjacent teeth, it is questionable if it should be used as an aid in endodontic diagnosis. When compared with the test solutions, 2% lidocaine with epinephrine anesthetized more teeth mesial and distal to the premolars for a longer duration. Therefore, the number of adjacent teeth anesthetized and the duration of anesthesia appear to be related to the vasoconstrictor. More distal teeth than mesial teeth were anesthetized with all solutions (except epinephrine alone). Kaufman et al. (5) found that teeth with longer roots were more difficult to anesthetize, specifically canines. This may possibly explain our findings since the anesthetic solution would have to travel a longer distance for the mesial teeth (canines). Birn (24) observed that perforations in the wall of the cribiform plate increased in the mandible from the incisors toward the molar. This could allow for placement of the anesthetic solution distally more readily than mesially. More research is needed to determine the exact pattern of anesthetic solution deposition related to adjacent teeth. For all solutions, needle insertion on the mesial was rated as mild pain (median of 1, Table 5) and indicated that patients did not generally find this initial needle insertion to be very painful. Distal needle insertion pain was rated as no pain (median of 0, Table 5) for the 2% lidocaine solution with epinephrine. This may be related to patients acceptance of the procedure or anesthesia of the soft tissues from the mesial injection. The statistically significant difference between 2% lidocaine with epinephrine and 2% lidocaine on distal needle insertion was probably related to the lower success rate of anesthesia with 2% lidocaine. The same was probably true for the difference between 2% lidocaine with epinephrine and the epinephrine solution (Table 6). Pain of injection (mesial and distal) for the anesthetic solutions was rated none to mild pain (median 0 to 1, Table 5) and indicated that patients did not generally find injection of the solutions very painful. Injection pain was rated moderately painful (median of 2, Table 5) for both the mesial and distal injections of epinephrine. Since epinephrine produced no anesthesia, the injections caused considerably more discomfort when compared with the 2%
.Vol. 14, No.8, August 1988
lidocaine with epinephrine. Further research should be done to determine if needle insertion and solution injection pain is different in maxillary and mandibular teeth and in different pathological conditions of the pulp. postinjection discomfort was experienced by 88% of the subjects on day 1. These results do not agree with some authors (2, 5) who reported few complaints of postoperative discomfort in clinical studies. Other authors (8, 10, II) have reported postinjection pain with this technique. The high potential for postoperative discomfort must be considered when using this technique clinically. Forty-nine percent of the subjects reported that at least one of the injected teeth felt high in occlusion. Although the occlusion was not checked clinically, it is doubtful that the teeth were actually in hyperocclusion. Most likely the teeth were sore to chewing and this may have accounted for the response that the teeth felt high. This is supported by the results that the mean duration of feeling high in occlusion, 2.1 days, was close to the mean duration of postinjection discomfort, 2.4 days. The development of herpes-like lesions and hematoma formation showed that these complications can arise following the periodontal ligament injection but the numbers were very small overall. Since all lesions resolved without sequelae, they cannot be considered serious. Faulkner (8) reported five patients had acute complications following intraligamentary injections. All resolved with antibiotic treatment or mouthwashes. Therefore, there may be a small risk of complications associated with the use of this injection technique, but this has to be considered a rare occurrence. The follow-up examinations showed that all pulps and the periodontium were within normal limits after 30 days. This corroborates previous clinical (4, 5, 8-10) and animal studies (14, 25-28) that damage was minimal and this injection technique was safe to the pulp and periodontium of clinically normal, healthy teeth. However, more research is needed to determine the effects on periodontally involved teeth and teeth with compromised pulps. CONCLUSIONS Concerning the use of the periodontal ligament injection as a primary anesthetic technique in human mandibular premolars, the following conclusions were reached: The periodontal ligament injection using 2% lidocaine with 1: 100,000 epinephrine was an effective technique for anesthetizing mandibular first premolars. However, the duration of profound pulpal anesthesia was approximately 20 min. Periodontal ligament injections of the mandibular first premolar, using 2% lidocaine with 1: 100,000 epinephrine, can anesthetize adjacent mesial and distal teeth. The periodontal ligament injection using 3% mepivacaine was effective in less than 50% of the teeth and had a duration of approximately 4 min. The periodontal ligament injection using 2% lidocaine anesthetized only 14 % of the teeth and had a duration of approximately 2 to 4 min. The periodontal ligament injection using a solution of 1:100,000 epinephrine alone was completely ineffective for anesthesia. The addition of epinephrine to 2% lidocaine increased the
Periodontal Ligament Injection
403
success and duration of anesthesia. Initial needle penetration and injection of 2% lidocaine with epinephrine, in clinically healthy teeth, were only mildly discomforting. Postinjection discomfort was experienced by the majority of the subjects (88%). The average duration was 2.4 days. Almost 50% of the subjects reported that their tooth felt high in occlusion for an average duration of 2.1 days. No clinically observable pulpal or periodontal damage was seen at 4 wk postinjection. This study was supported by research funding from the Ohio Association of Endondontists, J. David Brilliant Memorial Fund. This article was adapted from a thesis submitted by Dr. Schleder in partial fulfillment of the requirements for the MS degree at The Ohio State University, Columbus, OH. A portion of this article was presented at the 42nd Annual Session of the American Association of Endodontists, San Diego, CA, and was honored by a graduate student research award. Dr. Schleder is in private practice limited to endodontics, Willoughby, OH. Dr. Reader is associate professor, Department of Endodontics, College of Dentistry, The Ohio State University, Columbus, OH. Dr. Beck is associate professor, Department of Diagnostic Services, The Ohio State University. Dr. Meyers is professor and chairman, Department of Endodontics, The Ohio State University. Address requests for reprints to Dr. Reader, Department of Endodontics, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH 43210.
References 1. Walton RE, Abbott BJ. Periodontal ligament injection: a clinical evaluation. J Am Dent Assoc 1981;103:571-5. 2. Malamed SF. The periodontal ligament (PDL) injection: an alternative to the inferior alveolar block. Oral Surg 1982;53:117-21. 3. Montagnese TA, Reader A, Melfi R. A comparative study of the GowGates technique and a standard technique for mandibular anesthesia. J Endodon 1984;10:158-63. 4. Khedari AJ. Alternative to mandibular block injections through interligamentary anesthesia. Quintessence Int 1982;2:231-7. 5. Kaufman E, Galili D, Garfunkel AA. Intraligamentary anesthesia: a clinical study. J Prosthet Dent 1983;49:337-9. 6. Grainger JK. Intraligamentary anesthesia. Dent Anaesth Sed 1982;11 :45-9. 7. Council on Dental Materials, Instruments and Equipment. Status report: the periodontal ligament injection. J Am Dent Assoc 1983;106:222-4. 8. Faulkner RK. The high pressure periodontal ligament injection. Br Dent J 1983;154:103-5. 9. Smith NG, Walton RE, Abbott BJ. Clinical evaluation of periodontal ligament anesthesia using a pressure syringe. J Am Dent Assoc 1983;107:953-
6. 10. Kaufman E, LeResche L, Sommers E, Dworkin S, Truelove E. Intraligamentary anesthesia: a double-blind comparative study. J Am Dent Assoc 1984;108:175-8. 11. Johnson GK, Hlava GL, Kalkwarf KL. A comparison of periodontal intraligamentary anesthesia using etidocaine HCI and lidocaine HCI. Anesth Prog 1985;9/10:202-5. 12. Glickman I. Clinical periodontology. Philadelphia: WB Saunders, 1972:36-7. 13. Smith GN, Walton RE. Periodontal ligament injection: distribution of injected solutions. Oral Surg 1983;55:232-7. 14. Fuhs MQ, Walker WA, Gough RW, Schindler WG, Hartman KS. The periodontal ligament injection: histological effects on the periodontium in dogs. J Endodon 1983;9:411-5. 15. Dreyer WP, van Heerden JD, Joubert JJ. The route of periodontal ligament injection of local anesthetic solution. J Endodon 1983;9:471-4. 16. Kim S. Ligamental injection: a physiological explanation of its efficacy. J Endodon 1986;12:486-91. 17. Olgart L, Gazelius B. Effects of adrenalin and falypressin (octapressin) on blood flow and sensory nerve activity in the tooth. Acta Odont Scand 1977;35:67-75. 18. Savoie SS, LeMay H, Taleb L. The effect of epinephrine on pulp microcirculation. J Dent Res 1979;58:2074-9. 19. Handler LE and Albers DD. The effects of vasoconstrictor epinephrine on the duration of pulpal anesthesia using the intraligamentary injection. J Am Dent Assoc 1987;114:807-9. 20. Dreven LJ, Reader A, Beck FM, Meyers WJ, Weaver J. An evaluation
404
Schleder et al.
of an electric pulp tester as a measure of analgesia in human vital teeth. J Endodon 1987;13:233-8. 21. Smith NG, Pashley DH. Periodontal ligament injection: evaluation of systemic effects. Oral Surg 1983;56:571-4. 22. Simon DE III, Jacobs LT, Senia ES, Walker WA III. Intraligamentary anesthesia as an aid in endodontic diagnosis. Oral Surg 1982;54:n-8. 23. Littner MM, Tamse A, Kaffe I. A new technique of selective anestihesia for diagnosing acute pulpitis in tihe mandible. J Endodon 1983;9:116-9. 24. Bim H. The vascular supply of the periodontal membrane. J Periodont
Journal of Endodontics Res 1966;1:51-68. 25. Brannstrom M. Nordenvall KJ. Hedstrom KG. Periodontal tissue changes after intraligamentary anesthesia. J Dent Child 1982;49:417-23. 26. Walton RE, Gamick JJ. The periodontal ligament in;ection: histologic effects on the periodontium in monkey. J Endodon 1982;8:22-6. 27. Peurach JC. Pulpal response to intraligamentary anesthesia in the cynomologus monkey. Anesth Prog 1985;3/4:73-5. 28. Lin L, Lapeyrolerie M, Skribner J, ShovUn F. Periodontal ligament injection: effects on pulp tissue. J Endodon 1985;11 :529-34.