Prof. Rasperini, in your opinion, what are the benefits of Ridge Preservation in the posterior region?
Prof. Rasperini: To reduce the need for a sinus lift. The upper jaw has limited basal bone due to significant pneumatization of the sinus and, of course, incurs additional bone loss after tooth extraction. So, a sinus lift is needed to create sufficient bone for implant placement. However, peremptory Ridge Preservation reduces the need for bone regeneration at the time of implant placement.
You have investigated the effects of Ridge Preservation in the posterior area.1 What was the goal of this study, and how was it designed?
Prof. Rasperini: Within this randomized study, Ridge Preservation with Geistlich Bio-Oss® Collagen and Geistlich Bio-Gide® was compared to spontaneous healing. We focused on the posterior maxilla, which means first and second molars. Our goal was to evaluate the ridge alterations after tooth extraction and the need for a subsequent sinus lift.
Did you find an advantage for Ridge Preservation over spontaneous healing?
Prof. Rasperini: After 6-months the major benefit was a significantly reduced need for sinus floor elevations.1 The bone is almost completely mature at that time, and a flapless implant placement can be performed easily, because of the ridge volume preserved with the biomaterials. The simple procedure makes a big difference compared with sinus floor elevation, which is a major surgical procedure.
What exactly is the patient benefit?
Prof. Rasperini: Most of the patients who undergo molar extractions are more than 70 years old. They are often on medications like Coumadin, Aspirin or other anticoagulants, and they can be diabetic. These are factors that influence wound healing and the outcome of any surgery. The patients appreciate avoiding a major surgery, and treatment time is shortened, so they have less pain and, of course, they avoid possible post-operative complications.
You have also evaluated the healing process histologically. What did you find?
Prof. Rasperini: Our histological evaluation revealed normal healing with a lack of inflammatory cells. Geistlich Bio-Oss® Collagen as well as Geistlich Bio-Oss® appeared to be surrounded by newly formed bone. This is advantageous for the dentist: on the one hand, the bone is stable – due to the mineral component of the graft that resorbs slowly; and on the other hand, the biological activity of the new and vital bone promotes osseointegration of the implant.
You used Geistlich Bio-Gide® as a collagen membrane to protect the augmented site. What makes you sure that this membrane has the right barrier function for this indication?
Prof. Rasperini: Wound healing consists of three phases: first comes the inflammatory phase, which takes about three days, then the proliferative phase, which takes about 15 days, and finally the maturation phase, which continues over three months.2 After one month, every cell in the wound “knows” exactly what to do, and the barrier function is no longer needed. That’s why Geistlich Bio-Gide® with its short barrier function is appropriate.
Is there a special advantage?
The advantage of Geistlich Bio-Gide® compared to other non-resorbable membranes is that it does not interfere with vascularization and nutrition processes between the soft-tissue flap and the underlying graft. Cells and blood vessels from the flap integrate with the membrane quickly and start to deliver nutrients and oxygen to the surgical site, contributing to the maturation of the tissues and the healing process. A recently published paper from our group shows this.9