I understand your concern.
Sometime upper respiratory tract infection like chronic sinusitis, tonsillitis or dyspepsia may also cause bad breath. If you have any, try to treat them.
Sometime dry mouth also causes bad breath. Drink plenty of water. To keep your mouth moist, be sure to consume plenty of water — not coffee, soft drinks or alcohol.
Chewing gum (preferably sugarless) or sucking on candy (preferably sugarless) also stimulates saliva, washing away food particles and bacteria.
You can use chlorhexidine mouth wash at times.
Use a fairly new toothbrush to remove any food particles in between the teeth.
Try to brush after any consumption of food.
If you still have problem after correcting the above factors you can consult again dentist for dental check up.
If you need further clarifications, I will be happy to explain you.
If you find this information helpful, please press ACCEPT button. Bonus is appreciated.
Your Positive Feed back is very important to me. Thank you for contacting Just Answer.