the ability to provide the patient with clinically adequate pain control is one of the major concerns all over the world . the development of local anesthesia has marked the beginning of new era in the field of dentistry . the use of local anesthetics ( las ) in dentistry and other surgical procedures as a means of pain control has been one of the medical marvels of twentieth century [ 1 , 2 ] . today lignocaine is the most commonly used local anesthetic agent in dentistry and is referred to as the  gold standard  for dental procedures [ 1 , 2 ] . although its properties resemble an ideal la agent , it is not completely free from cardiovascular toxicity and has an inherent vasodilating property [ 1 , 3 , 4 ] . as a result of the vasodilating characteristic , it has to be combined with a vasoconstrictor , such as adrenaline , to decrease its rate of absorption at the injection site and hence prolong the duration and depth of anesthesia . the use of adrenaline as a vasoconstrictor is sometimes contraindicated for medically compromised patients . to overcome these disadvantages , centbucridine , chemically known as 4-n - butylamino-1,2,3,4-tetrahydroacridine hydrochloride , is a new quinoline derivative with la action . it was synthesized at the central drug research institute , lucknow , india , by patnaik et al . and has the advantage of having an inherent vasoconstrictor property . many studies have been done on centbucridine in the medical field including ophthalmic surgery [ 5 , 6 ] , subarachnoid , and spinal   blocks . however , in dentistry , only a few have been published [ 2 , 9 , 10 ] , and most of them were carried out in the early eighties . however , all of the published literature has shown centbucridine as a potent and reversible la . it has been proven to be as effective as other la agents in ophthalmology [ 5 , 6 ] and in subarachnoid blocks . it has not been thoroughly evaluated in the dental field , and therefore this study was done to evaluate its efficacy . the aim was to compare the efficacy of 0.5% centbucridine hcl to 2% lignocaine hcl with adrenaline ( 1  :  200  000 ) for various parameters required in the dental field . to assess and compare the onset ( in seconds ) , duration ( in minutes ) , and depth ( using a visual analogue sore ) of anesthesia in healthy adults between lignocaine and centbucridine . to monitor and compare the cardiovascular response ( pulse and blood pressure ) in patients on the two las . this was a double blind randomized control trial comparing the effects of 2% lignocaine hci with adrenaline ( 1  :  200  000 ) and 0.5% centbucridine hci . it was done during june 2009 till december 2009 on outpatients attending the gujarat university , government dental college in india . all patients were healthy adults according to asa - i classification and aged between 18 and 60 years old . all patients who attended as outpatients for dental extractions and met the criteria were asked to participate in the study . they each randomly received a single anesthetic dose of either 0.5% centbucridine hci or 2% lignocaine hci with adrenaline . each patient was asked to select one of two brown sealed envelopes which contained the two treatment options . the operator administered a single cartridge of la agent using the inferior alveolar nerve block standardized technique as described in handbook of local anesthesia . the operator was handed the loaded syringe by a qualified medical nurse and was unaware of the type of la that he was administering . the name of the anesthetic ampoule was covered with a permanent marker which ensured that the operator was blinded . the study population was divided into two groups : group i ( centbucridine ) and group ii ( lignocaine ) . intradermal sensitivity tests were done prior to administration of the la , and any patient who tested positive was excluded from the study . the onset , duration , depth , and cardiovascular measurements were carried out by a qualified medical nurse . the time taken for the onset and duration of local anesthesia anesthesia was confirmed objectively by a pinprick test using a 20 gauge sterile needle which was applied over the attached gingival of the tooth to be extracted . it was confirmed subjectively when the patient first described symptoms of anesthesia for example  numbness or tingling sensation over lower lip . this was the time interval between the onset of anesthesia and when the patient reported subjective feelings of normal sensation . this was judged subjectively by the patient using a standardized visual analogue score ( vas ) . the score ranged from  0  to  5  with  0  being  no pain  and  5  being the most severe intense pain , which the patient could not bear . a low score ( 0 ) meant that the patient felt no pain at all ; a moderate score ( 1 and 2 ) meant that the patient felt mild pain ; a score of ( 3 and 4 ) meant that the patient felt moderate pain ; a high score ( 5 ) meant that the patient felt excruciating and unbearable pain . the systolic and diastolic blood pressure ( bp ) was measured in mm of mercury , and the pulse rate was measured using beats per minute . the measurements were done preoperatively ( base line ) , and then at 10 , 20 , 30 , and 60 minute intervals after the administration of the la . the same sphygmomanometer was used for all patients , and the nurse completed the recordings using standard guidelines . any signs of an allergic reaction including itching , redness , and localized swelling were recorded .   in cases where additional doses of la were required , changes in the heart rate ( pulse ) , systolic , and diastolic blood pressure at various time intervals were analyzed against preoperative values in each group . there was a fairly equitable distribution of cases between the two groups in terms of age , gender , and baseline blood pressure and pulse readings . of these , 100 patients received centbucridine ( group i ) and 98 received lignocaine ( group ii ) . there were slightly more females ( 53% ) than males , and the average age was 37.7 years ( see table 1 ) . the average time for the onset ( seconds ) and duration ( minutes ) of anesthesia is reported in table 2 . patients who received centbucridine reported a significantly longer duration of anesthesia compared to those who received lignocaine . table 3 shows the depth of anesthesia as recorded by the patient using the visual analogue score ( vas ) . the range was from 0 ( no pain ) to 5 ( severe , unbearable pain ) . the mean heart rate ( beats per minute ) at different time intervals is shown below ( table 4 ) . both las significantly increased the heart rate at the 10 minutes interval . at the other later time intervals , , there was a statistically significant increase in systolic bp at the 10 minute interval , after which there were no significant changes . in terms of the mean diastolic bp , there were no statistically significant differences in the bp over the time period intervals . there were almost equal numbers of patients in both groups , and the age and gender distribution was equally distributed . there were no significant differences between the groups in terms of demographical characteristics , and hence the groups could be compared to each other . the average time required for onset of anesthesia was just under three minutes , and centbucridine was significantly shorter . on average , patients felt the anesthetic effect of centbucridine about 14 seconds quicker than that of lignocaine which is clinically not significant . these results are within the reported range of initiation of anesthesia as reported by others to be between 1 and 6 minutes [ 2 , 9 ] . this could be due to the inherent vasoconstrictive effect of centbucridine as compared to lignocaine . patients reported an average anesthesia of 2.5 hours ( 151 minutes ) for centbucridine compared to under 2 hours ( 111 minutes ) for lignocaine . a possible reason could be the fact that since centbucridine has a natural vasoconstrictive effect , the la solution remained close to and around the nerve tissue for a longer period of time . the solution was prevented from being absorbed and dispersed , and this could have resulted in the longer duration of anesthetic time that was obtained . no patients reported a score of more than 1 ( mild annoying pain ) , and all patients were sufficiently anesthetized to carry out the procedures . there was mild and transient elevation of heart rate in both the groups at the 10 minute interval . however , at all subsequent evaluations , the heart rate had returned to the preanesthesia value . in all of the cases , therefore , after the 10 minute interval , the patients were much more relaxed , the fear had decreased , and their anxiety had been reduced . it was therefore understandable that their heart rate was high at the 10 minute mark but reduced and returned to normal by the 20 minute interval and at all subsequent evaluations . mild elevation of this parameter during initial time was attributed due to anxiety and fear as discussed above . this has also been reported by other authors [ 1 , 2 , 9 ] . this has been shown to increase the blood pressure and heart rate in some studies [ 1 , 9 ] and is contraindicated to some medically compromised patients . in this study , although there were no medically compromised patients , lignocaine did not significantly increase the blood pressures and heart rate . there were no adverse or allergic reactions to either of the las in our sample population . earlier episodes of an allergy to lignocaine have been reported but are very rare [ 1012 ] . since the sample population in the study consisted of about 200 patients , it is not surprising that there were no patients who reported adverse reactions . centbucridine has showed an antihistaminic activity by blocking the h1 histamine receptors which makes it an ideal la agent in patients with known allergy to other conventional las [ 2 , 5 ] . however , it must be noted that the sample population in the study was relatively small and as a result . lignocaine , matching it in terms of time of onset , depth of anesthesia , and cardiovascular effects . it produced no side effects or toxic reactions and confirmed its safety for use in this sample population . we can recommend centbucridine as a la agent for dental procedures which may last up to 2 hours . it is also recommended that centbucridine could be confidently used in medically compromised patients where lignocaine or adrenaline is contraindicated .
the development of local anesthesia in dentistry has marked the beginning of a new era in terms of pain control . 
 lignocaine is the most commonly used local anesthetic ( la ) agent even though it has a vasodilative effect and needs to be combined with adrenaline . 
 centbucridine is a non - ester , non amide group la and has not been comprehensively studied in the dental setting and the objective was to compare it to lignocaine . 
 this was a randomized study comparing the onset time , duration , depth and cardiovascular parameters between centbucridine ( 0.5% ) and lignocaine ( 2% ) . 
 the study was conducted in the dental outpatient department at the government dental college in india on patients attending for the extraction of lower molars . 
 a total of 198 patients were included and there were no significant differences between the las except those who received centbucridine reported a significantly longer duration of anesthesia compared to those who received lignocaine . 
 none of the patients reported any side effects . 
 centbucridine was well tolerated and its substantial duration of anesthesia could be attributed to its chemical compound . 
 centbucridine can be used for dental procedures and can confidently be used in patients who can not tolerate lignocaine or where adrenaline is contraindicated .