Dental floss

Lore & Background

Levi Spear Parmly, a dentist from New Orleans, is credited with inventing the first form of dental floss in 1819. He recommended running a waxed silk thread through the interstices of the teeth to dislodge irritating matter. Floss was not commercially available until 1882, when the Codman and Shurtleft company started producing unwaxed silk floss. In 1874, Asahel M. Shurtleff received the first patent for dental floss, predating later patents.

During World War II, physician Charles C. Bass popularized the use of nylon floss, which was developed by DuPont in the late 1930s. Nylon was found to be better than silk due to greater abrasion resistance and ability to be produced in great lengths and at various sizes. Floss became part of American and Canadian daily personal dental care routines in the 1970s.

Reader's Guide

Dental floss holds a significant place in oral hygiene history as the first interdental cleaning device, invented by Levi Spear Parmly in 1819. Its development from silk to nylon improved durability and accessibility, leading to widespread adoption in the 1970s. Despite its long-standing recommendation by dental professionals to prevent gingivitis and plaque buildup, the scientific evidence for its efficacy as an adjunct to tooth brushing remains limited and debated. The American Dental Association claims up to 80% of plaque can be removed by flossing, but systematic reviews have found weak or unreliable evidence for significant clinical benefit. The 2015 US Dietary Guidelines omitted flossing, sparking controversy. Floss is available in various forms, including waxed, unwaxed, and tape, with no significant difference in plaque removal between types. Its use requires proper technique, and specialized wands exist for ease of handling. The legacy of dental floss is one of widespread cultural adoption tempered by ongoing scientific uncertainty about its necessity.

Did You Know?

• Levi Spear Parmly invented dental floss in 1819, recommending waxed silk thread.
• Johnson & Johnson Corporation received the first patent for dental floss in 1898.
• Nylon floss was developed during World War II by physician Charles C. Bass.
• The 2015 US Dietary Guidelines did not include a recommendation about flossing.

From Contamination to Control: The Birth of Isolation

Before the mid-nineteenth century, dental practitioners worked in an environment where saliva and oral bacteria freely infiltrated the operative site, frequently compromising the outcome of a procedure and sometimes leading to the loss of the tooth entirely. In 1864, Sanford Christie Barnum, working in the United States, conceived a solution: a thin square sheet of rubber that could be draped over the teeth to create a sealed, dry working field. The concept, later borrowed into German dental vocabulary as Kofferdam, was far from finished. In 1882, Dr. S. S. White refined the design by rethinking how the central hole was punched, improving the fit around the target tooth. Yet the dam still struggled to stay in place. That problem was ultimately solved when Dr. Delous Palmer introduced the metal clamp—a small, tooth-specific device that grips the crown at the gingival margin and locks the sheet firmly around the isolated tooth. Together, these three innovations transformed a simple sheet of rubber into the precision isolation tool still central to modern operative dentistry.

The Art of Isolation: Technique in Practice

The rubber dam is not simply draped into the mouth; its application is a deliberate, multi-step procedure tailored to the specific tooth or teeth requiring treatment. Clinicians choose among single-tooth isolation, multi-tooth isolation, or a split-dam configuration depending on the clinical scenario. The sheet—typically a 150-millimetre square of latex or nitrile—is perforated with a dedicated dam punch so that the holes align with the curve of the dental arch when isolating several teeth. Once the appropriate holes are punched, the dam is positioned over the target tooth and secured with a metal or flexible-plastic clamp that seats snugly along the gingival margin, creating a seal that blocks saliva ingress. Because the tight clamp can cause subjective discomfort, the operator may apply a topical anaesthetic gel or liquid to the gingiva beforehand. A frame, made from stainless steel or polymer plastic, then holds the sheet taut so it does not drape over the working field or tangle in instruments. Dental floss is often tied around the clamp as a safety tether against aspiration.

Where the Rubber Dam Fits in Modern Dentistry

The primary clinical role of the rubber dam is moisture control—preventing saliva, blood, and oral micro-organisms from contaminating the operative site while simultaneously protecting the patient from inhaling or swallowing small instruments and filling materials. This makes it indispensable in endodontic work such as root canal therapy, where a sterile field is critical, and in fixed prosthodontics involving crowns and bridges, where composite and bonding agents must remain dry during placement and curing. It also features in fissure sealant application, implant placement, and certain veneer procedures. Despite its recognized value, the rubber dam sits at the centre of an ongoing professional debate. Although it is widely regarded as a standard of care supported by evidence, surveys indicate that a significant proportion of practitioners either use it only selectively or avoid it altogether. Some dentists employ it routinely across all restorative cases, while others reserve it for the most contamination-sensitive procedures. This divergence in practice means that the dam's presence in a given treatment room often reflects individual clinician preference and training as much as any universal protocol.

The Toolkit: Materials, Clamps, and Frames

Behind the seemingly simple act of isolating a tooth lies a carefully curated set of instruments and accessories. The dam sheets themselves are manufactured in thicknesses ranging from 0.14 to 0.38 millimetres, and most producers offer latex-free nitrile alternatives for patients with allergies, as well as autoclavable variants for infection control. The clamps come in a wide array of shapes and sizes, each engineered to match the unique crown morphology of different teeth, ensuring a snug grip at the gingival margin without damaging the periodontal tissue. Frames, available in stainless steel, polypropylene, or other polymer plastics, feature small peripheral pins that lock the sheet in place and keep it stretched. When radiography is planned, clinicians prefer the plastic frames because their lower radiodensity renders them virtually invisible on the X-ray, preventing superimposition over the tooth of interest. The dam punch, forceps, and auxiliary items such as OralSeal, wooden wedges, and Wedjets round out the kit. In particularly challenging cases, a clinician may adapt the standard clamp using a carved gypsum cast, a technique described by NCE Cazacu, to achieve a secure fit where conventional clamps fall short.