PTFE membranes are textured on one side to provide traction for fibroblasts in the gingiva so they will adhere to the membrane and prevent the incision line from opening. While there may be research on this, we at SteinerBio are interested to find out if that is actually the case.
To determine what effect texturing has on gingival opening and what effect texturing has on bone regeneration, we simply reversed the membrane and followed the healing response. We used a textured d-PTFE membrane made by Dentsply, under the brand Symbios. The following case was a ridge augmentation in the right posterior mandible. The alveolus was decorticated and grafted with Ridge Graft Kit, which is a combination of our putty and OsseoConduct βTCP granules. The graft material was covered by a d-PTFE Teflon membrane with the textured side down. The membrane was not supported with titanium, nor was it secured with tacks. The case was followed to evaluate the timing of opening of the incision line and the amount of bone regeneration.
Membrane Texture-Up or Down?Does It Matter?
Pre-operative radiograph
The incision lines did not open during the healing phase, so the membrane was left to be removed during implant placement. The membrane can be seen above the alveolar ridge under the gingiva illustrated by the green arrow. A space under the membrane indicates the bone and membrane are separated by a connective tissue layer.
3 months and 10 days after grafting, the site is opened for implant placement. The membrane is firmly attached to the underlying tissue.
The membrane is removed. However, a layer of membrane remains attached to the regenerated bone. Under the remaining thin layer of residual membrane, a dense alveolar crest is present. The residual layer of membrane could not be lifted off the crest. The only option was to scrap off what appeared to be an osteoid layer of bone that integrated with the textured portion of the membrane. The flaps were extended to ensure the entire membrane was removed.
After removing the osteoid/residual membrane layer from the alveolus dense bone, residual βTCP granules are noted. OsseoConduct™ βTCP granules are a component of Ridge Graft Kit™ and are designed to be resorbed in about 4 to 6 months. Complete resorption of the granules never takes place until the bone is loaded. The resulting remodeling to carry that load resorbs the woven bone and encases βTCP granules into cancellous and cortical bone. The green arrow identifies the original mandibular cortical ridge.
The ridge augmentation was successful in providing a few millimeters of vertical ridge height and good horizontal augmentation for a 5.4 diameter implant. This simple ridge augmentation procedure is designed for augmenting the width of the alveolus. For vertical ridge augmentation, our 3D printed βTCP scaffolds are utilized.
So what does this tell us about the textured vs untextured?
The smooth side of the membrane up maintained closure of the wound during the 3-month, 10-day regeneration phase and the membrane did not expose. The textured surface integrated with what appears to be an osteoid layer of bone resulting in good bone regeneration and good bony crest. While one case does not determine predictability, the reversal of the membrane either had no negative effect on the procedure or actually facilitated an improved outcome. Personally, we question if texturing provides any additional benefits to preventing the flaps from opening. The surgical technique and biocompatibility of the graft material appear to be the critical factors. The integration of bone into the textured membrane appears to have facilitated a well-developed alveolar crest with a broad dense alveolar ridge at 3 months and 10 days. It is unlikely that any other graft material would produce osteoid integration to the membrane surface, so this outcome is most likely unique to this graft material.
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