A Preliminary Report on a Method for Studying the Permeability of Expanded Polytetrafluoroethylene Membrane to Bacteria In Vitro: A Scanning Electron Microscopic and Histological Study

Abstract

The technique of guided tissue regeneration using expanded polytetrafluoroethylene (ePTFE) membranes has been shown to be effective in implant dentistry (bony defects, extremely thin alveolar ridges, and implants placed in fresh extraction sockets). One of the drawbacks associated with the use of membranes is their premature exposure with consequent bacterial contamination. The aim of this study was to examine the possibility that oral bacteria migrate through the occlusive portion of ePTFE membranes and to determine the time needed for microorganisms to pass from the outer surface to the inner surface of the membranes. A removable acrylic device was adapted to the molar-premolar region of one quadrant of the jaws in each of three volunteers. Five cylindrical teflon chambers were glued to the buccal aspect of each device. The chambers were divided into two rooms separated by the inner portion of a ePTFE membrane. The outer room was open to the oral cavity allowing plaque accumulation; the inner room was isolated from the oral cavity by the ePTFE membrane. One of the 5 chambers was completely closed and used as control. The test period lasted for 4 weeks. Every week, one chamber was removed from each device and processed for scanning electron microscopic and histologic examinations. Our study showed the possibility that oral bacteria may contaminate ePTFE membranes exposed to the oral cavity. One specimen showed partial bacterial penetration after 2 and 3 weeks, but after 4 weeks, all membrane specimens demonstrated bacterial contamination.(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontitis vs. Peri-Implantitis: The Same Disease? The Same Treatment?

“…Complete penetration was found in all specimens in three to four weeks, and the authors recommended that prematurely exposed membranes be removed immediately to "prevent bacterial infection of the underlying regenerating tissues". Another study by Simion et al (1994b) also reported a small number of leukocytes on non-exposed e-PTFE membranes free of bacteria and a high number of bacteria on exposed sites with a corresponding reduction in bone regeneration. Consideration has been given to the application of an antibiotic such as metronidazole gel to the e-PTFE membrane on the day of insertion Sander et al, 1994).…”

“PASS” Principles for Predictable Bone Regeneration

“…Other possible reasons for the reduced amount of bone formation are contamination of the membrane with oral microflora caused by an open wound. [25][26][27][28] More rapid resorption of bone grafting materials in areas of membrane exposure has also been reported. Jovanovic et al 29 examined 11 patients with dehiscence defects on the facial aspect of 19 threaded implants.…”

Developing Implant Esthetics in Compromised Ridge

“…Additionally, membrane exposure may necessitate premature removal, resulting in less than optimal results. 10 It would be desirable therefore, to use a resorbable membrane , but maintains its barrier function for as long as possible. Resorbable membranes with a rapid resorption profile may not exclude the connective tissue long enough for bone to completely fill the defect.…”