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OR 19 Anesthesia and heart rate effects of the supplemental IO injection of etidocaine and 3% mepivacaine
Vol. 25, No. 4, April 1 9 9 9
~,.iO~on I Anesthesia and heart rate effects of the supplemental IO injection of etidocaine and 3% mepivacaine. PStabile, A. Reader, E. Gallatin*, M.Beck, J. Weaver The Ohio State University, Columbus, Ohio The long-acting anesthetic agent etidocaine and 3% mepivacaine have not been compared for supplemental intraosseous anesthesia; nor has the heart rate effects of etidocaine with 1:200,000 epi. been determined during intraosseous anesthesia. The purpose of this study was to compare the anesthetic efficacy and heart rate effects of a supplemental intraosseous injection, using the Stabident system, of 1.5% etidocaine (1:200,000 epi.) and 3% mepivacaine in mandibular first molars. Using a repeated-measures design, 48 subjects randomly received three combinations of injections at tt~-ee separate appointments spaced at least two weeks apart. The combinations were: (1) inferior alveolar nerve block (1AN)+IO injection of 1.8ml of 1.5% etidocaine (1:200,000 epi.); (2) IAN+IO injection of 3% mepivacaine; (3) IAN+mock IO injection [control]. The first molar was blindly tested with an Analytic Technology pulp tester at 2-min. cycles for 60 rain. Heart rate (pulse rate) was measured with a pulse oximeter. Anesthesia was considered successful when two consecutive 80 readings were obtained. One hundred percent of the subjects had lip numbness. The results showed anesthetic success was significantly increased (p<0.05), as analyzed by Bonferroni-adjustedWilcoxon signed-ranks tests, for 60 minutes with etidocaine and 30 minutes with mepivacaine compared to the IAN block alone. The etidocaine solution increased the heart rate 90% of the time (average 32 beats/min.) while 3% mepivacaine had a minimal effect on heart rate. We concluded that the IO injection of 1.5% etidocaine ( 1:200,000 epi.) provided a longer duration of supplemental pulpal anesthesia compared to 3 % mepivacaine but the etidocaine solution increased the heart rate.
OOR] Evaluating three Ni-Ti file systems. Mohamed M. Khalefa and lsmail I. EISherif E1-Azhar University, Cairo, Egypt The aim of this research was to compare the cutting efficiency and change in root canal angles after using three types of Ni-Ti files (light speed, great taper and Onyx-R files). Thirty extracted lower first molar were used in this experiment, the occlusaI endodontic cavity was performed to gain access to the root canals and the distal root was amputated in the furcation area. Only the root canal length of the mesio buccal canal was recorded which will be the only canal instrumented. The specimens were placed vertically in transparent acrylic blocks till the level of the cervical line. A device was constructed to place the specimens in a definite place in relation to the cone of the X-ray machine. Preoperative X-rays were performed to the specimens from the buccal and mesial sides, then the root canal angles were recorded using Weine and long axis technique. The specimens were divided into three groups, ten each. The first group was instrumented using light speed system, the second group was instrumented using great taper files and the third group was instrumented using Onyx-R files. X-rays were taken to the specimens post-operatively from the buccal and mesial sides, the change in the root canal angles were evaluated, recorded and compared with the pre-operative X-rays. Barium sulphate ( Radio opaque material ) was introduced into the canals pre-operatively and post-operatively for all the specimens then X-rays were taken in order to compare the change in root canal diameter at 1, 3, 5 and 7 mm levels beginning from the apex of the root. The results were statistically analyzed and ANOVA test was performed. There was a highly significant difference between the groups at P< 0.001 and the light speed technique showed the least changes in root canal angles and the best conservative results, followed by the great taper files and the Onyx-R files.
Journal of Endodontics • 287
O~[ 2_Y_2
Cytotoxicity of six endodontic materials using the 51Cr release method. M.O. G6rduysus, M. G6rduysus, M. Ercan, I. Etikan
Hacettepe University, Ankara, Turkey This study evaluated the cytotoxicity of 4 root canal sealers AH26, Biocalex, CRCS and Endomethasone, and 2 retrofilling materials, IRM and amalgam. A total of 24 x 106 L929 mouse fibroblasts in 60 ml Eagles' MEM were labeled with 5~Cr, The radioactivity of the supernatant was counted in a gamma counter as reference (R). The labeled cell suspension was divided into 60 tubes. The freshly mixed test materials were placed in 10 tubes each, centrifuged, and incubated at 37 °C for 12 h (5 tubes per material) or 72 h (5 tubes). The supernatant from these tubes was then tested for radioactivity (T). The mean percentage of the 5~Cr release for each material and time interval was calculated (T/Rx 100). A 2 ml pure suspension of labeled cells was used as a negative control, while a similar suspension with added 0.5 ml formocresol was used as positive control. Results were analyzed according to the FDA Toxicity Assessment Index. For all materials except amalgam, the percent of 5~Cr release at 72 h was significantly higher than at 12 h (Wilcoxon signed-rank test, p<0.05). The groups varied significantly at both the 12 h and 72 h time intervals (ANOVA and Mann-Whitney U test, p<0.0001). These results suggest that all 6 materials tested are toxic at 12 h, whereas at 72 h, CRCS and IRM are non-toxic, Endomethasone, Biocalex and AH26 are toxic and amalgam is severely toxic.
O~2] Changes in root canal geometry after preparation assessed by high resolution computed tomography. O. Peters*, A. Laib, B. Mayer, E Barbakow Dept. o f Conservative Dentistry and Inst. for Biomedical Engineering, ETH and Univ. o f Zurich, Switzerland Alterations in root canal morphology during canal preparation may vary depending on the technique used. These alterations have been evaluated in-vitro measuring cross-sections before & after preparation. This study employed high resolution scanning tomography to assess changes in the canals' paths after preparation to avoid loss of specimens which always occurs in destructive analytical techniques. A micro computed tomography scanner (CT, cubic resolution 34#) was used to analyze 19 canals in 7 extracted maxillary molars. Teeth were scanned before and after canal preparation with a) K-files, b) Lightspeed and c) ProFile. A special mounting device enabled repeated precise repositioning and scanning of the specimens after preparation. Differences in surface area (AA in mm2) and volume (AV in mm3) of each canal before and after preparation was calculated using custom-made software. AV ranged from 0.64 to 2.86 (mean 1.61 _+0.7); AA varied from 0.72 and 9.66 (mean 4.t6.+2.63). Respective to treatment mode, AV (and zXA)were 1.28_+0.57 (2.58+ 1.83), 1.79.*_0.6(4.86.+2.53) and 1.81_+0.57 (5.31+_2.98) for K-File, ProFile and Lightspeed, respectively. Factorial ANOVA and Scheffe's tests revealed that the influence of the canal type was significant (p<0.01 for AV. p<0.05 for AA), but there were no significant differences between the preparation techniques used (p>0.05). In conclusion, under the conditions of this pilot study, variations in canal geometry before preparation were of more importance on the changes during preparation than the techniques themselves. Consequently, studies comparing the effects of root canal instruments on canal anatomy will have to take preoper.a_tiveca0al geometry into consideration. The non-destructive technique fulfills this requirement more than adequately.
~,.iO~on I Anesthesia and heart rate effects of the supplemental IO injection of etidocaine and 3% mepivacaine. PStabile, A. Reader, E. Gallatin*, M.Beck, J. Weaver The Ohio State University, Columbus, Ohio The long-acting anesthetic agent etidocaine and 3% mepivacaine have not been compared for supplemental intraosseous anesthesia; nor has the heart rate effects of etidocaine with 1:200,000 epi. been determined during intraosseous anesthesia. The purpose of this study was to compare the anesthetic efficacy and heart rate effects of a supplemental intraosseous injection, using the Stabident system, of 1.5% etidocaine (1:200,000 epi.) and 3% mepivacaine in mandibular first molars. Using a repeated-measures design, 48 subjects randomly received three combinations of injections at tt~-ee separate appointments spaced at least two weeks apart. The combinations were: (1) inferior alveolar nerve block (1AN)+IO injection of 1.8ml of 1.5% etidocaine (1:200,000 epi.); (2) IAN+IO injection of 3% mepivacaine; (3) IAN+mock IO injection [control]. The first molar was blindly tested with an Analytic Technology pulp tester at 2-min. cycles for 60 rain. Heart rate (pulse rate) was measured with a pulse oximeter. Anesthesia was considered successful when two consecutive 80 readings were obtained. One hundred percent of the subjects had lip numbness. The results showed anesthetic success was significantly increased (p<0.05), as analyzed by Bonferroni-adjustedWilcoxon signed-ranks tests, for 60 minutes with etidocaine and 30 minutes with mepivacaine compared to the IAN block alone. The etidocaine solution increased the heart rate 90% of the time (average 32 beats/min.) while 3% mepivacaine had a minimal effect on heart rate. We concluded that the IO injection of 1.5% etidocaine ( 1:200,000 epi.) provided a longer duration of supplemental pulpal anesthesia compared to 3 % mepivacaine but the etidocaine solution increased the heart rate.
OOR] Evaluating three Ni-Ti file systems. Mohamed M. Khalefa and lsmail I. EISherif E1-Azhar University, Cairo, Egypt The aim of this research was to compare the cutting efficiency and change in root canal angles after using three types of Ni-Ti files (light speed, great taper and Onyx-R files). Thirty extracted lower first molar were used in this experiment, the occlusaI endodontic cavity was performed to gain access to the root canals and the distal root was amputated in the furcation area. Only the root canal length of the mesio buccal canal was recorded which will be the only canal instrumented. The specimens were placed vertically in transparent acrylic blocks till the level of the cervical line. A device was constructed to place the specimens in a definite place in relation to the cone of the X-ray machine. Preoperative X-rays were performed to the specimens from the buccal and mesial sides, then the root canal angles were recorded using Weine and long axis technique. The specimens were divided into three groups, ten each. The first group was instrumented using light speed system, the second group was instrumented using great taper files and the third group was instrumented using Onyx-R files. X-rays were taken to the specimens post-operatively from the buccal and mesial sides, the change in the root canal angles were evaluated, recorded and compared with the pre-operative X-rays. Barium sulphate ( Radio opaque material ) was introduced into the canals pre-operatively and post-operatively for all the specimens then X-rays were taken in order to compare the change in root canal diameter at 1, 3, 5 and 7 mm levels beginning from the apex of the root. The results were statistically analyzed and ANOVA test was performed. There was a highly significant difference between the groups at P< 0.001 and the light speed technique showed the least changes in root canal angles and the best conservative results, followed by the great taper files and the Onyx-R files.
Journal of Endodontics • 287
O~[ 2_Y_2
Cytotoxicity of six endodontic materials using the 51Cr release method. M.O. G6rduysus, M. G6rduysus, M. Ercan, I. Etikan
Hacettepe University, Ankara, Turkey This study evaluated the cytotoxicity of 4 root canal sealers AH26, Biocalex, CRCS and Endomethasone, and 2 retrofilling materials, IRM and amalgam. A total of 24 x 106 L929 mouse fibroblasts in 60 ml Eagles' MEM were labeled with 5~Cr, The radioactivity of the supernatant was counted in a gamma counter as reference (R). The labeled cell suspension was divided into 60 tubes. The freshly mixed test materials were placed in 10 tubes each, centrifuged, and incubated at 37 °C for 12 h (5 tubes per material) or 72 h (5 tubes). The supernatant from these tubes was then tested for radioactivity (T). The mean percentage of the 5~Cr release for each material and time interval was calculated (T/Rx 100). A 2 ml pure suspension of labeled cells was used as a negative control, while a similar suspension with added 0.5 ml formocresol was used as positive control. Results were analyzed according to the FDA Toxicity Assessment Index. For all materials except amalgam, the percent of 5~Cr release at 72 h was significantly higher than at 12 h (Wilcoxon signed-rank test, p<0.05). The groups varied significantly at both the 12 h and 72 h time intervals (ANOVA and Mann-Whitney U test, p<0.0001). These results suggest that all 6 materials tested are toxic at 12 h, whereas at 72 h, CRCS and IRM are non-toxic, Endomethasone, Biocalex and AH26 are toxic and amalgam is severely toxic.
O~2] Changes in root canal geometry after preparation assessed by high resolution computed tomography. O. Peters*, A. Laib, B. Mayer, E Barbakow Dept. o f Conservative Dentistry and Inst. for Biomedical Engineering, ETH and Univ. o f Zurich, Switzerland Alterations in root canal morphology during canal preparation may vary depending on the technique used. These alterations have been evaluated in-vitro measuring cross-sections before & after preparation. This study employed high resolution scanning tomography to assess changes in the canals' paths after preparation to avoid loss of specimens which always occurs in destructive analytical techniques. A micro computed tomography scanner (CT, cubic resolution 34#) was used to analyze 19 canals in 7 extracted maxillary molars. Teeth were scanned before and after canal preparation with a) K-files, b) Lightspeed and c) ProFile. A special mounting device enabled repeated precise repositioning and scanning of the specimens after preparation. Differences in surface area (AA in mm2) and volume (AV in mm3) of each canal before and after preparation was calculated using custom-made software. AV ranged from 0.64 to 2.86 (mean 1.61 _+0.7); AA varied from 0.72 and 9.66 (mean 4.t6.+2.63). Respective to treatment mode, AV (and zXA)were 1.28_+0.57 (2.58+ 1.83), 1.79.*_0.6(4.86.+2.53) and 1.81_+0.57 (5.31+_2.98) for K-File, ProFile and Lightspeed, respectively. Factorial ANOVA and Scheffe's tests revealed that the influence of the canal type was significant (p<0.01 for AV. p<0.05 for AA), but there were no significant differences between the preparation techniques used (p>0.05). In conclusion, under the conditions of this pilot study, variations in canal geometry before preparation were of more importance on the changes during preparation than the techniques themselves. Consequently, studies comparing the effects of root canal instruments on canal anatomy will have to take preoper.a_tiveca0al geometry into consideration. The non-destructive technique fulfills this requirement more than adequately.