ABSTRACT
Recognizing canal configuration is necessary for correct endodontic therapy; and having no information about canal configuration results in failure of therapy. Since one of the most effective factors in canal configuration is race, we decided to conduct a laboratory and clinical research in Isfahan. The aim was to recognize canal configuration of the maxillary second premolars and compare the clinical and laboratory results.1- Laboratory study [In vitro]:At first we selected 105 maxillary second premolars and then disinfected them in CLONA 5.25%. We made a correct access cavity on the teeth. In order to vacate pulp tissue in chamber and canals, we placed them in H2O2 35% for 15 days. Then, we placed them in HNO3 [5%] for 3 days in order to be decalcified. 70%,90%,100% isopropyl alcohol was used to dehydrate the teeth. After the above processes, we injected India ink in -1.8 P in the canals and sealed access cavity by zonaline cement. Methyl Salicylate was used to clear the teeth and the configuration of the canals were observed directly. 2- Clinical study [In vivo]: In this study, we selected 132 maxillary second premolars of patiuents treated at the graduate and under graduate departments of Isfahan University School of Dentistry. Then we studied every radiograph using a negatoscope and the results of both methods were analyzed and compared. 1-Laboratory [In vitro] Out of 105 maxillary second Premolars[researchable], 30 type I [28.6%], 13 type II [%12.4], 48 type III [45.7%], 12 type IV [11.4%] and 2 with three canal [1.9%] were observed according to the Weine classification.2-Clinical [In vivo] Results: Out of 132 maxillary second premolars, 82 were type I [62.13%], 21 type II [15.91%], 25 type III [18.92%], and 4 were type IV [3.04%] . In this study, three canals were not observed. The results of this study are different from other researches. Perhaps, race and method of study were influential. Also, the clinical results were different from laboratory results as the laboratory study method is more exact