Introduction:Functionalcrownlengtheningisoneofthemostcommonsurgicalproceduresthatfacilitatingrestorativetreatment.Itwasdoneonteethwithinadequateclinicalcrownsinthepresenceofdeepandsubgingivalpathologies.Inadequateclinicalcrownsdefinedastoothwithlessthan2mmcervico-incisalofsound.CaseReport:The32yearsoldfemalepatientcomplainedonbrokenrestorationonupperleftanteriortoothsinceoneweekago.Healsocomplainedaboutupperrightanteriortooththatturnedbrown.Thetoothhadreceivedrootcanaltreatmentwithdirectcompositerestorationsince3yearsago,buttherestorationontooth11and21wasbroken.Theremainingcrownontooth11and21waslessthan2mm.Theperiapicalradiographexaminationshowedtooth11and21wasnon-hermeticobturation.Functionalcrownlengtheningandrootcanaltreatmentwasperformedonteeth11and21,withporcelaincrownrestorationandfiberpost.Conclusion:Functionalcrownlengtheningresultaffectsthequalityofpostretreatmentrestoration.Thesuccessoffunctionalcrownlengtheningismarkedbynorecurrentgingivalhyperplasiaafterfunctionalcrownlengthening.