In our previous article, we covered the essential armamentarium needed for effective rubber dam use in routine dental practice. Building on that foundation, this article will delve into the various options for rubber dam clamps, explore the benefits of floss ties, and examine the versatile use of Teflon tape. Each of these components plays a crucial role in enhancing the efficiency and effectiveness of rubber dam application, making this discussion vital for optimising your dental procedures.

The Benefits of Quadrant and Anterior Tooth Isolation

When placing a rubber dam, consider quadrant isolation for posterior teeth and, in the author's experience, isolating from the second premolar to the second premolar for anterior teeth. While isolating additional teeth may require only a small amount of extra time, it provides several notable benefits, including:

  • Enhancing the overall visual perception of the operative field: In other words, you can see more because more light enters the area. Additionally, the operator can observe the relationship between the tooth they are working on and the adjacent teeth. This is useful when performing direct resin work and aiming to mirror the line angles on a tooth in the opposite quadrant, which is critical for anterior teeth.

  • Improving access: This is particularly important when working on areas that are challenging to see with direct vision (e.g., disto-palatals). Broader isolation improves the ability to use a mirror. Many dentists struggle to place their palatal stent to restore anterior teeth when the rubber dam is in situ. A common reason for this is that the isolated field is too restricted to accommodate the stent.

  • Removing excess water: If the rubber dam clamp is placed away from the treated tooth (e.g., the second molar is clamped when working on the second premolar), water from irrigation tends to pool away from the tooth being worked on. This means it is easier for the assistant to effectively remove water without hindering the dentist. In addition, the author’s experience shows there is far less splashing and fogging of the mirror when working indirectly.

  • Scanning improvements: When preparing teeth for indirect restorations, the author scans the upper and lower arches and records the MIP position prior to placing the rubber dam while the local anaesthetic is working. Quadrant rubber dam is placed, and the tooth is prepared. After preparation, the tooth is rescanned using the adjacent teeth as reference points. This makes impression scanning far easier and more efficient for onlays (and other supra-gingival restorations) because the tissue management stage is more efficient.

With these benefits in mind, let's delve into the various options available for rubber dam clamps, floss ties, and Teflon tape. Each of these components plays a crucial role in optimising the effectiveness of rubber dam application.

Selecting Rubber Dam Clamps

There is a vast array of rubber dam clamps on the market today. The author prefers to use only a few types because this simplifies inventory, reduces expenses, and improves communication between the dentist and the assistant.

Clamps may be winged or wingless. A wingless clamp is placed on the tooth, and then the dam is placed over it. In contrast, the rubber dam is placed on a winged clamp before being positioned on the tooth. The author finds the latter approach easier and more convenient.

The recommended clamps are:

  • 00 for premolars and canines
  • 2A for larger premolars
  • 8A for molar teeth
  • 212 for retraction of facial surfaces of anterior teeth
  • Brinker B4 for retraction of premolar teeth and canines

Light particle abrasion (sandblasting) of the clamps with 29-micron alumina at low pressure (2 bar) is excellent for cleaning and reduces the glare of the metal clamp when photographing the area.

The Function of Floss Ties

The use of floss ties has become increasingly popular in recent times. They fulfill the following functions:

  • Improve the seal of the rubber dam margin, reducing the ingress of crevicular fluid, blood, and saliva.
  • Retract the rubber dam and free gingival margin/papillae, resulting in improved access when working on margins that are intra-sulcular.
  • When tied around the neck of a tooth and secured to the rubber dam frame, they can retract the rubber dam and prevent it from collapsing inwards, thus improving access to facial surfaces.
  • They also look impressive on lecture slides and social media images.

The author prefers monofilament tape rather than braided floss. Conventional braided floss tends to become bonded to tooth structure during the adhesive stages of the procedure and can be extremely difficult, if not impossible, to remove. Tape (e.g., Oral-B Glide) is much simpler to remove and can be flicked off with a sharp curette or number 12 scalpel.

There are many approaches to tying floss ties, and all have validity. The author’s approach is as follows:

  1. A 30 cm (12 inch) length of tape is cut. This is used to floss all the contacts prior to placing the rubber dam.
  2. The rubber dam and the frame are placed. The dam is flossed through the contact points.

 

The Teflon tape is passed through one contact point of the tooth being worked on.
Figure 1: The Teflon tape is passed through one contact point of the tooth being worked on.
  1. The tape is passed through one contact point of the tooth being worked on. (IMAGE 1)

 

The tape is looped around the palatal and passed through the other contact point, leaving two free ends on the facial.
Figure 2: The tape is looped around the palatal and passed through the other contact point, leaving two free ends on the facial.

 

  1. The tape is looped around the palatal and passed through the other contact point leaving two free ends on the facial. (IMAGE 2)
  2. The two free ends are crossed over each other on the facial and repeatedly pulled bucco-palatally: a good analogy is the movement of a towel when you dry your back after a shower. This movement tends to rapidly invert the rubber dam apically into the sulcus.
A double loop is tied on the free ends, and the tape is tightened and pulled apically.
Figure 3: A single loop is tied between the free ends and tightened.

 

  1. A double loop (identical to the first throw of a surgical knot) is placed on the two free ends and the tape tightened. On tightening, the tape is pulled apically (upwards in the upper arch and downwards in the lower arch). (IMAGE 4)
A single loop is tied between the free ends and tightened.
Figure 4: A double loop is tied on the free ends, and the tape is tightened and pulled apically.

 

  1. A single loop (identical to the locking throw of a surgical knot) is tied between the two free ends and the tape knot tightened. (IMAGE 3)
The two free ends cut short.
Figure 5: The two free ends cut short.

 

  1. The two free ends can then be either tied to the rubber dam frame or cut short (around 5-10mm). If the operator elects to cut the tape the author finds a 12-scalpel blade to be much easier than scissors. (IMAGE 5)

 

When the procedure is complete, the tape should be removed. The easiest way to achieve this is to cut next to the knot with the tip of a number 12 scalpel blade. The tape can then be easily pulled out with college tweezers.

It is good practice to count the number of floss ties used and ensure they are all removed to avoid inadvertently leaving tape behind in the sulcus when the patient is dismissed. Failure to do so may result in gingival abscesses and poor tissue resolution.

Techniques for Teflon Tape Use

Teflon tape (or PTFE thread seal tape) is very useful in day-to-day dental practice.

PTFE was discovered by accident in 1938 by DuPont chemist Roy Plunkett and was trademarked as Teflon. Teflon tape was developed by William Skidmore of Whitford Corp in 1969 as a solution for sealing pipes.

It comes in several thicknesses, with the most useful being those designed for gas pipes (thicker) and water pipes (thinner). The thinner water pipe tape is used by the author for isolating teeth during bonding, as it passes between contacts and prevents deflection of indirect restorations, which can result in open contact points. Care must be taken during placement because the tape tears very easily.

The tape twisted into a braid serving as a retraction cord.
Figure 6: The tape twisted into a braid serving as a retraction cord.

 

The tape can also be twisted into a braid and used as a retraction cord, either with or without a rubber dam. (IMAGE 6) When isolation of margins is required for bonding (e.g., ceramic veneers or adhesive crowns), it is often easier to remove than conventional retraction cord.

The tape employed as a wedge in interproximal areas.
Figure 7: The tape employed as a wedge in interproximal areas.

 

The gas tape is thicker and heavier and is best employed for:

  1. Wedging interproximal, the tape often performs better than a wedge in areas of adverse anatomy for example the fossa canina of the upper first premolar because it freely adapts to any contour. The lower left in this image used tape as a wedge (IMAGE 7).
  2. Covering screws in implant retained restorations prior to placement of composite resin,
  3. Sealing coronal canal access of pulp chambers after first stage endodontics. For avoidance of doubt, a temporary restoration should be placed over the tape.
Tape blocking interproximal undercuts, aiding tissue retraction, and enhancing visibility in scans for temporary restorations.
Figure 8: Tape blocking interproximal undercuts, aiding tissue retraction, and enhancing visibility in scans for temporary restorations.

 

  1. Blocking out interproximal undercuts when fabricating temporary restorations prevents the temporary restorative material from flowing into undercuts and either breaking or locking in place when polymerized. The tape also provides good tissue retraction, and the pressure often achieves hemostasis. The author will often pack the tape (finishing 1mm below the prepared margin), fabricate the temporary restoration, and then leave the tape in situ for the impression or scan. The high contrast of the tape is well picked up in the scan. (IMAGE 8)
Tape anchored in place with a rubber dam clamp to avoid displacement during rinsing and drying procedures.
Figure 9: Tape anchored in place with a rubber dam clamp to avoid displacement during rinsing and drying procedures.

 

The tape is easily displaced during rinsing and drying procedures and should ideally be anchored in position. The simplest and most secure way is to employ a rubber dam clamp, such as an 8A (molar) or 2 (premolar). (IMAGE 9)

Understanding and using the right tools and techniques for effective rubber dam placement can significantly enhance the quality of dental procedures. By carefully selecting rubber dam clamps, floss ties, and Teflon tape, you can improve access, visibility, and overall patient outcomes. In our next article, we will delve into the sequence of rubber dam placement, offering valuable tips and tricks to further refine your technique and optimise your practice.


Jason Smithson, BDS (Lond), DipRestDentRCS (Eng), is a member of Spear Resident Faculty.

References:

Gerdolle D, Browett S, Gresnigt MMM. The Digital Impression Under Rubber Dam: Clinical Insights For An Accurate Scan. Ned Tijdschr Tandheelkd. 2023 Feb;130(2):73-79


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