Dental Learning Systems, LLC produces and offers intellectual content whose value can not be replaced or resold. Therefore, CDEworld.com and Dental Learning Systems, LLC does not accept cancellations, requests for modifications, or returns for credit or refund. All sales are final. CDEworld.com and Dental Learning Systems, LLC strives to provide quality products, reliable service, and fast electronic delivery. Please contact us within 24 hours if the event that you have registered for does not match the receipt issued to you. Should you require historical copies of CE certificates please review your profile on CDEWorld and/or contact us and we will be happy to help you.