The use of implant-supported dental prostheses to replace missing teeth has resulted in a renewed focus on extraction techniques, particularly in the esthetic zone. Removing the tooth without damaging the alveolar socket can facilitate post-operative healing, ridge preservation techniques and subsequent implant placement. This module will describe the techniques to remove a hopeless tooth with implant placement in mind.

After completing this ITI Academy Module, you should be able to recognize factors that may lead to tooth extraction, describe the biological effects of tooth loss on the dentoalveolar process, select the most appropriate minimally traumatic technique to remove a tooth.

The first objective focuses on the factors leading to tooth extraction. Several medical conditions or habits can contribute to tooth extraction. They include, but are not limited to diabetes mellitus, smoking, pregnancy, drug-induced disorders caused by anticonvulsants, alcium channel blockers or anti-rejection drugs, hematologic disorders including leukemia, and immune system disorders such as AIDS, autoimmune diseases and immune disorders caused by immunosuppressants or cancer treatment.

Dental conditions and diseases that can contribute to tooth extraction include, but are not limited to, caries, periodontal diseases as seen in this clinical example, tooth removal needed in preparation for a dental prosthesis, pulpal infection or inflammation, and trauma.

Factors Leading to Tooth Extraction, Key Learning Points: Among others, tooth extraction can be necessary due to the following reasons: Medical conditions and habits, dental conditions or diseases and trauma.

The amount of bone volume available at a proposed implant site can significantly affect the outcome of implant treatment. It is well-documented that extraction of a tooth results in significant resorption of the alveolar process, leading to a reduction of the dimensions of the alveolar ridge. This is of particular importance in the esthetic zone, where lack of bone volume can result in improper positioning and angulation of the implant, which could lead to unesthetic outcomes. To overcome this and ensure a prosthodontically driven position of the implant, additional treatment interventions are often necessary to augment the ridge, requiring increased treatment time and costs.

The sequence of healing events in post-extraction sites has been demonstrated in a dog model. After extraction of a tooth a blood clot forms that is composed mainly of erythrocytes and platelets. At day 3, lysis of erythrocytes is found and the clot starts to be replaced by vascularized tissue. New blood vessel formation is visible after 7 days. By day 14, immature bone or woven bone can be seen on the socket walls. After 30 days, the socket is filled with woven bone, which is slowly replaced with lamellar bone by day 90. At day 180 some of the lamellar bone is replaced by bone marrow spaces.

Comparison of animal and human studies suggests that the healing steps in human extraction sockets closely resemble the steps in the dog model. As seen in these two histologies from a dog experiment and from a human biopsy, well-formed bony trabeculae are visible after 12 weeks that are very similar in appearance.

The net effect of tooth extraction on alveolar ridge dimensions can be described as loss of both bone height and bone width. The largest amount of resorption occurs on the buccal aspect of the ridge, leading to a shift of the center of the ridge to the palatal aspect, which may compromise implant placement. The amount of bone loss in the buccolingual width can be up to fifty per cent whereas the loss of vertical bone height is approximately 2 to 4 millimeters. Most of the ridge resorption appears to occur during the first 4 months following tooth extraction.

It is important to consider the expected amount of post-extraction ridge resorption. An important indicator for resorption is the periodontal phentype or biotype. Thick and thin biotypes have recently been correlated with buccal plate thickness as measured using Cone Beam Computed Tomography or CBCT.

The periodontal phenotype has been shown to significantly correlate with the thickness of the labial plate the alveolar crest position, the width of keratinized tissue, the gingival architecture, and probe visibility. Therefore, thin phenotypes are more predisposed to bone resorption after tooth extraction. Assessing the phenotypes prior to tooth extraction can aid the clinician in predicting the degree of horizontal and vertical resorption post-extraction.

As the healing process of each individual patient varies, the timing of implant placement post-extraction should be based on the desired clinical outcome of the wound healing process rather than on descriptive terms or rigid time frames following extraction. Knowledge of the socket healing process therefore aids the clinician in selecting the desired time point for implant placement. The time points of healing related to implant placement are: Immediate or Type 1 implant placement, which is performed at the time of tooth extraction, Type 2 or early placement, which is performed at 4 to 8 weeks after extraction when soft tissue healing has occurred. Partial bone healing is found after 12 to 16 weeks. Implant placement at this time point is known as Type 3 placement. Late or Type 4 placement is performed after 16 or more weeks of healing.

Effects of Tooth Loss, Key Learning Points: Significant bone remodeling occurs after tooth loss. The periodontal biotype correlates with buccal plate thickness. There are different time points for implant placement based on the stages of socket healing.

Regardless of the desired time point for post-extraction implant placement, preservation of the alveolar ridge begins with the minimally traumatic extraction of the failed tooth. This has led to the introduction of several new instruments of varying design and cost to help the clinician preserve the alveolar socket walls, which, in turn, increases the likelihood of a successful result.

The basic extraction instrumentation traditionally consists of elevators, forceps and a handpiece. Traditionally these instruments were used with the expeditious removal of the tooth in mind, regardless of the risk of damage to the alveolus. Nevertheless, these instruments can also be applied in a minimally traumatic fashion when combined with sectioning of the tooth without damaging the socket walls.

Traditionally, speed has been favored during tooth extraction with little regard to the damage caused to the alveolar bone and surrounding tissues. Certain basic modifications in the technique, however, can reduce trauma to the alveolus and soft tissue: Clinicians should use a flapless approach which means avoiding elevation of a flap. Clinicians should avoid buccolingual expansion of the alveolus and avoid removing bone due to an aggressive extraction technique. In addition, clinicians should not use excessive force that could traumatize the hard and soft tissues.

To remove a tooth with minimal trauma using traditional instrumentation, the tooth should first be sectioned. Sectioning can be accomplished with a tapered cross-cut fissure bur or similar and appropriate irrigation. After sectioning, the roots can be individually elevated and removed with minimal trauma to the surrounding alveolus. Care should always be taken to remove any remnants of apical pathology and to thoroughly debride the socket prior to continuing with the desired treatment. If there is any doubt about the complete removal of remnants, an intraoperative periapical radiograph can be obtained.

Advances in luxation techniques have resulted in the development of several instruments used to separate the tooth from the alveolus without damaging the buccal plate. These include: the periotome, the powered periotome, proximator instruments and piezosurgery.

A periotome is typically an inexpensive thin blade-like instrument that is utilized to sever the periodontal ligament attachment around a tooth. The tip is delicate, therefore it should not be used to elevate the tooth as it can easily bend or fracture.

Combining the periotome with the careful use of a surgical mallet allows for deeper penetration into the periodontal ligament space and enables more effective luxation of the tooth. Care must be taken not to twist the periotome in an elevation-type motion.

The video shows the application of the periotome in combination with a rubber-tipped surgical mallet for minimally invasive separation of the periodontal ligament fibers. Once the periotome is seated into the periodontal ligament space, it is moved laterally to facilitate its removal. At no point is the periotome twisted to elevate the root. The periotome is seated only at the mesial, distal and palatal aspects of the root. This is to avoid fracturing the buccal plate or tearing the facial gingiva. Final tooth removal is accomplished with an elevator or forceps.

The powered periotome eliminates the need for a surgical mallet by powering and controlling the vertical advancement of the periotome into the periodontal ligament space. The degree of power is controlled by the use of a control box and a foot pedal. The degree of control and depth of penetration of the periotome is vastly improved when compared to the manual technique and, in addition, no irrigation is required.

Similar to the periotome, the powered periotome is positioned into the mesial, distal and palatal periodontal ligament spaces, taking care to avoid the buccal aspect. Clinicians should refrain from twisting the tips to prevent breakage. Patients may dislike the use of the powered periotome due to the sound and the fast, repetitive action of the unit. With anxious patients, sedation should be considered when applying this technique. The careful use of elevators and forceps accomplishes the final removal of the tooth.

Proximators are stronger, more robust versions of the periotome that can be used to sever the periodontal attachment and periodontal ligament. Due to their construction, they can also be utilized to expand the alveolus mesiodistally and to elevate the root of the tooth. They are available in multiple tip designs and configurations to address most clinical situations.

Piezosurgery utilizes tuned piezoelectric technology to cut hard tissue without damaging soft tissue. Different inserts are available for various applications including tooth extraction. The main advantages of piezosurgery are soft tissue protection, optimal visibility in the surgical field, decreased blood loss, less vibration and noise, increased comfort for the patient and protection of tooth structure. More favorable osseous repair and remodeling has been reported with piezosurgery than with carbide or diamond burs.

Piezosurgery utilizes different extraction inserts for different anatomic locations. The removal of a fractured tooth can be facilitated by using piezosurgery and the appropriate extraction inserts. In order to prevent damage to the alveolar bone due to heat, modest flap reflection is strongly recommended to allow irrigation and constant motion of the insert tip. Any elevation with or torquing of the inserts should be avoided. Finally the rest of the tooth is carefully removed.

Slow vertical tooth displacement has been successfully applied in the past in the form of orthodontic extrusion. Recently, new instruments and techniques have been introduced that allow removal forces to be directed vertically for the immediate extraction of a failed tooth without expansion of the alveolar socket walls. This minimizes trauma to the buccal plate and surrounding tissue. Two designs have gained popularity: The anchor-and-pulley vertical extraction system, and the anchor-and-lever vertical extraction system.

Orthodontic extrusion is indicated in situations with significant deficiencies in bone or soft tissue, and when the patient is open to or in need of orthodontic therapy. Significant bone and soft tissue regeneration has been shown when utilizing forced tooth eruption in preparation for implant placement. Disadvantages of this technique, however, are the time needed to complete extrusion, the cost of the procedure and the potentially negative esthetic impact during the extrusion process. This is a clinical example of a patient with a failed maxillary right central incisor and a significant buccal hard and soft tissue defect. Orthodontic extrusion was indicated in order to create a more favorable tissue situation prior to extraction and immediate implant placement. Following two years of orthodontic extrusion, significant improvement in hard and soft tissue volume is visible. Note that excess tissue was created on the facial aspect of the central incisor.

An anchor-and-pulley vertical extraction device allows for minimally invasive extraction of tooth roots when conventional removal with elevators and forceps is not possible. It is also useful in the esthetic zone, when minimal disturbance to the soft and hard tissue is desired. The system is keyed around a device that utilizes a pulley system and controlled traction to elevate and extract the tooth root along the long axis of the root. This virtually eliminates pressure on the socket walls that can occur with conventional luxation and elevation.

The extraction process begins by using a periotome to separate the root and the alveolar bone. This is followed by the use of a twist drill to prepare a channel into the tooth which is at least seven millimeters deep. An anchor is screwed into the root through this channel. The traction cable is hooked into the anchor, guided over the pulley and placed into the extraction device. The device is positioned with the teflon pad in contact with the occlusal surfaces of the adjacent teeth. Extraction then takes place by slow, controlled turning of the hand screw.

An anchor-and-lever system also utilizes an anchor in the form of an extraction screw. However, instead of using teflon pads, support is derived from impression material placed into a modified impression tray or plate. The extraction device then attaches to the top of the extraction screw and the tooth is slowly displaced vertically by turning a knob to activate the lever arm.

The extraction process begins in a similar way as with the anchor-and-pulley vertical extraction device. Using the periotome, luxation is performed to separate the root and the alveolar bone. In the next step, the remaining tooth structure is reduced to create a flat surface which will allow the extraction screw anchor to fully seat and engage. The channel for the extraction screw is prepared using drills of increasing diameter and the appropriate extraction screw is selected. The extraction screw should protrude through the protector plate. The plate is then filled with impression material and seated over the extraction screw. Once the impression material has set, the lever device is aligned over the plate and engages the extraction screw. Turning the knob on the end of the device activates the lever arm, slowly elevating the tooth vertically out of the socket.

Each of the two systems has its own advantages and disadvantages. An advantage of the anchor-and-pulley system is the optional use of impression material for additional support. It also allows better visibility to confirm tooth removal, and it can be used on molar teeth. However, disadvantages are that its use is time-consuming in multi-rooted teeth and the anchor screws are generally shorter than in the anchor-and-lever system, thus making it difficult to engage wide, decayed or over-instrumented canals.

In contrast, the anchor-and-lever system has longer anchor screws to allow deeper engagement of roots. In addition, wider screws are available, which may allow engagement of wider canals. Impression material is needed which may provide additional lateral support to the alveolus. However, this mandatory use of impression material requires more chair time, and reduces visibility as the impression material can cover the extraction pin. In addition, the costs for consumables are higher due to the use of impression material. Finally, the anchor-and-lever device can only be used up to the second premolar due to the limited space posteriorly. Selection of a particular device is based on individual preference. Both designs appear to induce only minimal trauma to the alveolus.

Extraction Techniques, Key Learning Points: Traditional extraction techniques and instrumentation may result in excessive trauma to hard and soft tissues, loss of bone and extended healing times. Applied correctly, traditional extraction instruments can be utilized in a minimally traumatic fashion when combined with a flapless approach and appropriate sectioning of the tooth. Modern minimally traumatic techniques and instrumentation can reduce trauma to the hard and soft tissues, minimize the risk of fracture of the socket walls and optimize subsequent procedures.

Module Minimally Traumatic Extraction Techniques, Summary: Minimally invasive extraction techniques offer many advantages over conventional extraction methodologies. The advantages include: Reduced trauma to the surrounding soft tissues, maintenance of the socket wall integrity with minimal subsequent ridge resorption, and improved predictability of subsequent procedures.