Hi sir...    The black spots in your teeth may be the cavitation...    Sensitivity to cold drinks also due to caries that reaches dentine layer of your teeth...   First and foremost X_ray should be taken to confirm the extent of carious lesion... Based on radiographic diagnosis we can tell the treatment plan whether you need simple fillings or Root canal treatment... The longiviety of filling material depends on type of filling material used and also based on your maintainence... Yellow stains may be due to plaque and calculus... you need to do cleaning(scaling) by dentists... No need to worry sir and dont lose your confidence .. Dental treatment is not costly sir only delaying of the treatment is only  progress the lesion and make it costlier...

By looking at your picture it's very difficult to say but u need to redo ur filling . Usually good filling stay for 5-6 months . #gandhisdentalcare# pedodontics# endodontics#estheticfilling#implantologist#wecareforsmile#vasantenclave#

You should go for filling and scaling. Regular visit to dentist in 6month. No need to worry. Don't depressed for this. This is not a huge problem.