In last month’s column, we discussed the fundamental instruments and equipment required to diagnose and treat dental conditions. This month, we will address advances that have made extractions easier. When extracting a firmly rooted tooth, it is important to consider how the tooth is attached to the surrounding bone. The area around the tooth is called the periodontium. The periodontium consists of the root surface (cementum), alveolar bone, gingival connective tissue, and periodontal ligament. The periodontal ligament spans a narrow space between the alveolar bone and the cementum of the root surface. Millions of periodontal ligament fibers need to be either torn or severed to allow a tooth to be delivered from its alveolus. The periodontal ligament is mainly composed of collagen fiber bundles (type I, III, and V collagen), matrix, and blood vessels. Among them, collagen fiber bundles are the most abundant component in the periodontal ligament, accounting for about 50–75 percent of the periodontal ligament’s volume.1 Dental elevators The first step is to detach the gingival connective with a blade or a periosteal elevator. A 15C scalpel blade is a favorite amongst veterinary dentists for incising gingival connective tissue and making releasing incisions if needed. Periosteal elevators are most helpful when sharp and used to elevate mucogingival flaps. Winged (a.k.a. Wiggs) dental elevators have thin wings that fit into the periodontal ligament space. Once the elevator is seated into the space, the instrument handle is turned to leverage the tooth, and stretch and tear the periodontal ligament fibers holding the tooth in its alveolus. Sometimes, winged elevators are sufficient to loosen a firmly rooted tooth. However, for challenging teeth, I reach for dental luxators. Luxators Luxators are like miniature scalpel blades that cut the periodontal ligament attachments, making extractions less about brute force and more about technique and finesse. Instead of twisting its handle, the luxator is inserted into the periodontal ligament space and moved side to side, like a windshield wiper. This motion allows the sharp blade of the luxator to extend deeper into the periodontal ligament space to cut more of the attachment structures. Since the periodontal ligament space is typically 0.25 mm wide, luxators are thin. Since luxators are thin, they may become dull or damaged easily. Frequent sharpening and frequent replacement are necessary. Some manufacturers have modular blades that can be removed from their handle and easily replaced. Replacement programs help you avoid frequent sharpening. These instruments are sharp; therefore, they must always be under control. Keep an index finger extended along the shaft of the elevator or luxator so when (not if) your instrument slips, your finger will act as a stop to hopefully prevent damage to important structures. A set of dental luxators and elevators with interchangeable blades. Photo courtesy Dr. John R. Lewis A 4 mm luxator blade. Note the very thin profile, designed to fit into a 250-micron-wide periodontal ligament space. Photo courtesy Dr. John R. Lewis Periotome and piezosurgical units Veterinary dentists and some general practices that perform extensive dental work may have more advanced instruments to remove stubborn teeth. An automated periotome can be very helpful for challenging extractions. Acting like a jackhammer that drives a thin blade into the periodontal ligament space, this device is not intended for use when the periodontal ligament space is ankylosed. Because the tips are so thin and flexible, tip breakage can occur. Piezosurgical units have revolutionized oral surgery in human and veterinary patients. We use our piezosurgery unit for maxillectomies and mandibulectomies, and occasionally for a challenging extraction. Piezosurgery tips designed for extractions can be used regardless of the presence of ankylosis. Piezosurgery tips are not as long as automated periotome tips, but they may be advanced up to approximately 10 mm to free up periodontal attachments. Burs Another very helpful tool for extractions is a high-speed bur with a long shaft and a very thin working end, which can be used to create a “moat” around a root that requires removal. The moat technique for removing stubborn roots has replaced the “pulverization” (a.k.a. “atomization”) technique of the past. Instead of drilling a root into oblivion, the moat technique locates the periphery of the root with a tiny, round bur while also removing some bone on the buccal surface of the root to create a window in the bone through which the root can be gently pried. My favorite bur for use in the moat technique is the ¼ surgical length round bur. A small luxator or a Davis root tip elevator, or the small end of a feline periosteotome can be used to fit into the space created by the bur on the lingual/palatal surface of the root, resulting in gentle leverage that will deliver the root. After removing the root, it is important to say, “What a cute little root!” Be careful when using the ¼ surgical length round bur. Since these burs are so dainty at their working end, it is easy for them to break off if you are heavy-handed with them or if the metal becomes fatigued. For this reason, the ¼ round bur is one we consider a single-use bur in our practice. Next time you extract teeth, think of how many millions of periodontal ligament fibers you bested that day. That’s something to feel good about! John Lewis, VMD, DAVDC, Fellow-AVDC OMFS, teaches at Silo Academy Education Center and practices at Veterinary Dentistry Specialists in Chadds Ford, Pa.
