Introduction
Dental avulsion is a common surgical procedure in dentistry, often involving the use of forceps to grasp and remove the tooth from its socket. However, the use of forceps can be associated with a certain degree of trauma to the surrounding tissues, resulting in pain, swelling, and post-operative complications, such as bone and root fractures. In recent years, a new tooth extraction technique that does not require forceps, called “Extraction Without Forceps” (EWF), has been developed. This technique, conceived and perfected by me, Dr. Fabio Cozzolino, is based on using elevators to luxate and remove the tooth a-traumatically.
Physical Principles of Levers
Levers are simple machines that allow the amplification of the applied force. The operating principle of a lever is based on the law of moments, according to which the moment of a force around a point is equal to the product of the force and its distance from the point. In other words, a small force applied at a great distance from the fulcrum can generate a large force at a short distance from the fulcrum.
Archimedes, the famous Greek mathematician and inventor, recognized the power of levers and stated:
“Give me a place to stand, and I will move the Earth.”
While hyperbolic, this statement illustrates the potential of levers to amplify force. Common examples of levers in everyday life include crowbars, scissors, and wheelbarrows.
The mechanical advantage of a lever is the ratio between the resisting force (the force to be overcome) and the driving force (the applied force). In the case of EWF, the resisting force is the tooth’s resistance to extraction, while the driving force is the force applied to the lever. The mechanical advantage depends on the length of the lever arms: the greater the arm of the driving force relative to the resisting force arm, the greater the mechanical advantage.
Types of Levers
From a biomechanical perspective, there are three types of levers, classified based on the position of the fulcrum, driving force, and resisting force.
- First-class levers: The fulcrum is between the driving force and the resisting force (e.g., seesaw, scissors).
- Second-class levers: The resisting force is between the fulcrum and the driving force (e.g., wheelbarrow, nutcracker).
- Third-class levers: The driving force is between the fulcrum and the resisting force (e.g., tweezers, fishing rod).
In EWF, depending on the position of the lever and the tooth, different types of levers may be used.
Custom Lever for Dr. Cozzolino
Each lever has its method of use. In general terms, the lever should pivot on the bone and be used with a rotational motion applied to the handle, along with pressure directed apically and toward the tooth to be extracted. This approach helps avoid damage to the adjacent tooth.
In dental extraction with an elevator, the biomechanical situation is dynamic and can vary depending on:
- The type of lever used: Elevators come in different shapes and sizes, each with its point of force application and different fulcrum.
- The position of the lever with the tooth: Depending on how the elevator is inserted and manoeuvred, the fulcrum can shift, allowing the elevator to act as a first-, second-, or third-class lever.
- The phase of extraction: During the initial luxation, the elevator may act as a first-class lever, with the fulcrum on the alveolar bone. Later, during the tooth elevation, it could function as a second-class lever, with the fulcrum on the adjacent tooth.
For these reasons, EWF utilizes the principles of all three types of levers.
Application of Levers in EWF
In EWF, levers are used to apply controlled forces to the tooth, exploiting the principle of levers to amplify the force and luxate and extract the tooth from the socket. The elevator is positioned between the tooth and the alveolar bone, and force is applied in an apical and lateral direction while simultaneously rotating the lever along its axis. The choice of the type of lever and the force application point depends on the shape and position of the tooth.
elevators for atraumatic extraction – Dr. Fabio Cozzolino
(Photo by Dr. Fabio Cozzolino – elevators for atraumatic extractions E.W.F.)
During a traditional tooth extraction with forceps, force is applied at two points, forcing the tooth to follow a predefined direction, which may not coincide with its path of least resistance. This can cause stress on the root and increase the risk of fracture, especially if the root is thin or has a pronounced curvature.
In contrast, during tooth extraction with elevators, force is applied at a single point, allowing the tooth to rotate and follow its path of least resistance within the socket. This way, the root experiences less stress, and the risk of fracture is significantly reduced.
For example, if you have a toy train on a track and apply an oblique force to it, its movement will not precisely follow the direction of the force but rather that of the tracks. Why? The force is applied at a single point, so the resultant force will push it in the direction of least resistance, following the track’s path. If forceps were used, it could change the train’s path, forcing its movement, which likely would not follow the path of least resistance, causing the train to derail.
Advantages of EWF
EWF offers several advantages over traditional extraction with forceps:
- Reduced perception of force: Using levers allows for a lower force to achieve the same extraction effect, reducing the patient’s perception of force.
- Lower risk of fractures: With EWF, the tooth is free to follow its path of least resistance during extraction, reducing the risk of root fractures.
- Faster extraction: The force amplification provided by levers allows for quicker tooth extraction. Often, an extraction can be completed in just a few seconds.
EWF Technique
The EWF technique involves the following steps:
- Anaesthesia: Local anaesthesia is administered to ensure patient comfort.
- Probing: A periodontal probe is used to evaluate the depth of periodontal pockets and the anatomy of the tooth.
- Elevator insertion: The elevator is inserted into the periodontal space, between the tooth and the alveolar bone.
- Force application: Controlled force is applied to the lever in an apical and lateral direction, rotating the lever along its axis. This first luxates the tooth and then avulses it from the socket.
- Tooth removal: Once the tooth is displaced from its socket, it is gently removed, possibly using dental forceps.
- Stitches: If possible, it is recommended to avoid stitches. While stitches stabilize the clot, they are also the primary cause of post-extraction alveolitis, as food can get trapped inside the socket, causing inflammation of the surrounding tissues.
Possible Complications
Like all techniques, this one is not free from complications and is operator-dependent.
Although the force applied by the operator is minimal, the force exerted on the tooth is significantly greater – due to the lever principle – and some complications can arise:
- Bone fracture: This can occur if the fulcrum, which must bear the load, fails, causing a bone fracture.
- Fracture of adjacent teeth: If force is applied by leveraging an adjacent tooth, it may result in a fracture of that tooth.
Clinical Experience
In my clinical practice, using EWF has led to a significant reduction in root fractures during dental avulsion. Although no scientific data is available to support this observation, my experience suggests a reduction of over 80% in fractures compared to traditional forceps extraction.
In my thirty years of experience, I have not encountered bone or adjacent tooth fractures. However, I have twice seen the fracture of a ceramic crown on an adjacent tooth, leading me to advise against using elevators between two teeth if the adjacent tooth has a ceramic crown.
My clinical data reinforce the idea that EWF is a less traumatic technique, more respectful of the tooth’s anatomy.
Conclusions
EWF represents a significant innovation in dental avulsion. This technique, based on applying the physical principles of levers, offers numerous advantages over traditional forceps extraction, including reduced patient perception of force, a lower risk of root fractures, and faster extraction times.
EWF is a safe and effective technique that can improve the patient’s experience during dental avulsion.
References and links
- L Montebugnoli, [Lever in tooth extraction. Physical and clinical principles] – Dental Cadmos, 1990 Oct 15;58(15):101-5. – PMID: 2279594
- L Montebugnoli, G P Rizzi, M A Vaccaro, [Forceps in tooth extraction. Method of use and working position] – Dental Cadmos, 1991 May 31;59(9):54-61. – PMID: 1864424
- Carl E Misch 1, Helena M Perez, Atraumatic extractions: a biomechanical rationale – Dent Today, . 2008 Aug;27(8):98, 100-1. –PMID: 18717405
- Tushar N Bhosale, Kalyani Bhate, Sherwin Samuel, George Jacob, Comparative evaluation of efficacy of physics forcep and conventional forceps for extraction of maxillary molars – Minerva Dent Oral Sci, 2024 Apr;73(2):75-80.
doi: 10.23736/S2724-6329.23.04740-X. Epub 2023 Jun 16. – PMID: 37326503
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