This article describes the creative ways in which PTFE (Polytetrafluoroeythlene) tape can be utilized in dental practice.
History and use within Dentistry
PTFE, discovered in 1938, often referred to as ‘Teflon’, is a versatile material made from Polytetrafluoroethylene. PTFE is a polymer of tetrafluoroethylene1 and consists entirely of carbon and fluorine, providing this material with unique physical properties. PTFE is commonly used in the plumbing industry as ‘PTFE thread seal tape’. Owing to its versatility, its use has been adapted to many differing applications, ranging from electronics to the musical instrument industry.2 This tape is wound on a spool with specific widths and thicknesses.
As a non-stick, easily adaptable and low-cost material,3 its use has been increasing in dentistry. Having a high melting point (327 Celsius),4 the material can be autoclaved, facilitating its use within Dentistry.5,6Table 1 highlights the key properties of PTFE tape.
High strength
Low modulus of elasticity
Good flexibility
Low coefficient of friction
Chemically inert
High melting point
Hydrophobic
Low cost
Some clinical applications of PTFE tape
Protecting adjacent teeth and restorations from contamination (Figure 1)
PTFE tape has characteristics7 which make it an ideal material for a variety of clinical situations. PTFE tape is hydrophobic and thus is resistant to saliva, solvents and acids. It will therefore not deform or degrade during use within the oral cavity. It can be easily adapted around adjacent teeth to reduce contamination or damage, for instance by 37% phosphoric acid etch during conditioning.
Protecting adjacent teeth during cementation (Figure 2)
PTFE tape is ‘almost’ chemically inert and has a low coefficient of friction;3 as such it can be closely wrapped around adjacent teeth without compromising the interdental space. Its ‘non-stick’ nature prevents any remnants from stagnating on the tooth tissue. The material's low modulus of elasticity and flexibility allows it to be stretched up to 2-fold its original length. It can therefore be elongated without risk of splitting.5
During implant dentistry, as a method to fill screw access channels (Figure 3)
Due to PTFE being easily manipulated, its use has become popular for the purposes of screw access channel filling. With the tape being rolled into a cylindrical shape, it can be directed into the screw access channel for implant-retained restorations.
During endodontics, as a spacer, under the provisional restorative material within the access cavity (Figure 4)
Owing to the material's shear strength and high break elongation,8 it may also be used as a mechanical barrier under a provisional restoration during orthograde endodontic therapy. Due to these properties, PTFE, unlike a cotton wool pellet, can be easily visualized on removal and removed without fear of tearing. In addition, the use of PTFE has been shown to reduce the bacterial contamination of the access cavity,9 in comparison to the use of cotton wool as a spacer. Furthermore, the use of PTFE beneath the provisional restorative material can help to provide firm and compressible support, to minimize the risk of breakdown of the provisional restoration, unlike the use of an endodontic sponge, which has been advocated by some practitioners.
During restorative dentistry as a retraction cord (Figure 5)
PTFE tape can be modified by twisting into a cord and placed into the gingival margin for use as a retraction cord. PTFE is hydrophobic, allowing placement into the sulcular environment without distortion.
As a ‘Teflon wedge’ to modify a matrix system (Figure 6)
PTFE can be compacted tightly owing to its high flexural strength. This makes it suited to modify a matrix system to gain a tight contact point. Although traditionally wedges may be used alone, the tape allows a more customized fit, with the clinician determining the degree of adaption by the matrix.
Protection of adjacent teeth and restorations during direct adhesive dentistry (Figure 7)
PTFE tape can be utilized throughout direct adhesive restorative dentistry, for instance to protect adjacent teeth from bonding agents or during a tooth wear build up case, to prevent composite restorations from bonding to each other.
During Class 1 occlusal cavities as a ‘microbrush stamp technique’ (Figure 8)
PTFE tape has been demonstrated to allow the replication of occlusal morphology when creating composite resin posterior restorations. The technique, which copies the occlusal morphology of the original unprepared tooth structure, has been termed the ‘microbrush occlusal stamp technique’.
As separation material used when undertaking ‘mock-ups’ or fabricating provisional restorations (Figure 9)
PTFE tape can be used as a means to prevent ‘mock-up’ restorations adhering to the underlying unprepared tooth surface or when fabricating a provisional restoration. PTFE, when wrapped around tooth structure, provides a thin uniform material covering. This, along with its low coefficient of friction,3 means that ‘mock-ups’ or provisional restorations can be fabricated without adhering to the underlying tooth structure.
As a means of blocking undercuts when undertaking impressions (Figure 10)
Due to the high break elongation of PTFE tape,7 the material can be used to block out undercuts from large embrasure spaces when taking impressions. In addition, this material can be threaded and used to isolate interproximally and between pontics during bridge cementing procedures.
Figure 1. Protecting adjacent teeth and restorations from contamination.Figure 2. Protecting adjacent teeth during cementation.Figure 3. During implant dentistry, as a method to fill screw access channels.Figure 4. During endodontics, as a spacer, under the provisional restorative material within the access cavity.Figure 5. During restorative dentistry as a retraction cord.Figure 6. As a ‘Teflon wedge’ to modify a matrix system.Figure 7. (a–c) Protection of adjacent teeth and restorations during direct adhesive dentistry.Figure 8. (a–c) During Class 1 occlusal cavities as a ‘microbrush stamp technique’.Figure 9. As separation material used when undertaking ‘mock-ups’ or fabricating provisional restorations.Figure 10. As a means of blocking undercuts when undertaking impressions.
Thickness of tape
PTFE tape can be purchased in varying thicknesses. Typically, these include 0.02 mm, available on a yellow spool and 0.075 mm on a white spool. The authors prefer to use the thinner 0.02 mm tape, for dental practice, due to its ability to be easily adapted and elongated, unlike the thicker variant.
Conclusion
This technique tip has discussed examples of the varying uses of PTFE tape in dental practice. Some of these uses have been described by Sattar et al.5 It can be concluded that PTFE tape is a versatile and cost-effective tool for the dental practitioner and can be used creatively in dental practice, for a number of clinical situations.
