Recognizing canal configuration is necessary for a correct endodontic therapy, and having no information about canal configuration causes failure in therapy.
Since one of the most effective factors in canal configuration is race, we decided to have a laboratory and clinical research in Isfahan. The aim is to recognize canal co figuration of the maxillary second premolar and compare the clinical and laboratory results.
1- Laboratory study (In vitro): 105 maxillary second Premolar were selated then .we disinfected them in CLONA 5.25%. We made a correct access cavity on the teeth. In order vacute the pulp tissue in chamber and canals, we placed them in H2O2 35% for 15 days. and HN03 5% for 3 days
to be decalcified. Then we used 70%, 90%, 100% isopropyl a1chole to dehidrate the teeth. After the above processes we injected India ink in - 1.8 P, in canals and canal configuration. Clinical study (In vivo): In this study we selected 132 maxillary second premolar treated in graduate and under graduate departments of Isfahan University school of dentistry. Then we studied every radiograph using a negatoscope, the results were analyzed the data.
1-laboratory (In vitro) results: Out of 105 maxillary second Premolar (researchable), 30 type 1(28.6%),13 type II (12.4%), 48 type III (45.7%), 12 type IV (11.4%) also 2 with three canal (1.9%) were out of Weine classification.
2- Clinical (In vivo) Results: Out of 132 maxillary second premolar, 82 type I (62.13%), 21 type 11 (15.91%), 25 type III (18.92%), 4 type IV (3.04%) in this study don't observe three canals.
The outcoming results of this study are different from other researches. Perhaps the differences are caused by some factors such as race and method. Also the clinical results are too different from laboratory results and it is because of method. The laboratory study is more prease.