• This seems to be the crux of the problem. The initial concept in human medicine was that illness in various parts of the body could be cured by extracting teeth and performing tonsillectomies, but this could not be supported statistically. Nevertheless, systemic health is affected by chronic periodontal infection. In humans, a negative impact of oral infection on systemic health has been documented, from the entry of oral microorganisms or their products into the bloodstream. Research cites that bacteremia is common, and gingival inflammation can be the source of significant microbial entry into the bloodstream.¹¹ Additionally, the pathogenesis of bacterial pneumonia in adult people primarily involves aspiration of bacteria that colonize the oropharyngeal region into the lower respiratory tract and failure of the host defense mechanisms to eliminate the contaminating bacteria, which subsequently multiply and cause infection.¹² Gram-negative bacilli, such as enteric species and Pseudomonas aeruginosa, can be cultured from the subgingival flora of patients with periodontal disease.¹² Bacterial migration can be provoked by mastication and oral hygiene procedures. The extent to which bacteremia of oral origin occurs appears to be related directly to the severity of gingival inflammation.¹¹ This concept represents a distinct mechanism by which these bacteria may gain access to the systemic circulation. Researchers of human dentistry report that there is little doubt that, under certain circumstances, microorganisms can move from one area of the body to another to establish their customary pathology in another locale.¹³ They cite that “bacteria metastasize to the heart, brain, kidney, liver, joints, gastrointestinal tract, and skin from other areas of the body, including the mouth. The pathways for the dissemination of infection are by direct spread or by blood or lymphatic metastasis of the infecting organisms, their toxic products, or tissue immunologic reactions to the organisms or their products.”¹⁴ Research in veterinary medicine is sparse on this subject, but cases of distant infection that originated in the mouth have been cited,¹⁵ and evidence is strong that the same phenomenon seen in people is seen also in animals.¹⁶

Objectives

• Periodontal therapy has three principal objectives: (1) pocket reduction or elimination of the soft and bony lesions, (2) eradication or arrest of the periodontal lesion, with correction or cure of the deformity created by it, and (3) alteration in the mouth of the periodontal climate that was conducive or contributory to allowing periodontal disease to become established, creating a more biologically sound environment.¹⁷ We cannot cite one pocket depth for all cats and dogs as being the point at which a periodontal depth is considered pathologic. In a domestic cat 1.0 mm is an abnormally deep gingival sulcus and, whereas 2 to 3 mm might be the outside limit for a normal gingival sulcus depth in a medium to large breed dog, 4.0 mm might be considered normal in a St. Bernard. To keep normalcy in perspective, the healthy gingival attachment is found in very close proximity (within 1.0 mm) of the cementoenamel junction. Attachment measurements greater than this should be noted as attachment loss, and treatment for this pathologic condition should be planned accordingly.

ROOT PLANING: CLOSED TECHNIQUE

General Comments

• Root planing is the process whereby residual embedded calculus and portions of the necrotic cementum are removed from the roots to produce a clean, hard, smooth surface that is free of endotoxin.¹⁸

• The objective, whether performed with specially manufactured thin ultrasonic periodontal tips (described later in this chapter) or by hand instrumentation, is to render the root surface biologically acceptable to the soft tissue wall of the periodontal pocket without causing unnecessary loss or damage to hard or soft tissues.

Technique

• The patient should receive a preoperative antibiotic if pus is present in the pocket or if the patient has any other systemic disease.

• A routine, systematic approach should be used on each quadrant and on each tooth. Specific curettes are selected because of their ability to reach to the depth of the pocket and adapt to the tooth surface.

• The blade of the instrument is inserted gently in the closed position; that is, the face of the instrument moves parallel to the tooth (Fig. 5-1, A). This allows the positioning of the curette apical to the calculus (often called the exploratory stroke).

• The blade of the curette is positioned against the root surface (adaptation) and opened (Fig. 5-1, B).

• The opened blade of the curette is withdrawn from the pocket in an oblique manner while applying pressure (known as the working stroke) (Fig. 5-1, C).

• Root planing is performed using a curette with overlapping strokes in horizontal, vertical, and oblique directions (also known as cross-hatching) (see the later section on gingival curettage). This may require additional cleaning strokes after all calculus has been removed, to obtain a smooth surface, being careful not to gouge the root surface. Subgingival root scaling becomes root planing after deposits have been removed from the surface and the scaling technique is employed to smooth the root surface.

• Cross-hatching creates an optimally smooth surface while maintaining root anatomy.

• As root planing is being performed, an assessment must be made, using a dental explorer, regarding the nature of the dental deposits and tooth surface. This evaluation determines how much pressure and in what direction the working strokes should be made. Closed root planing by curette is a complex and precise coordination of visual, mental, and manual skill that makes subgingival instrumentation one of the most difficult of all dental skills. The success of the procedure rests on the operator’s familiarity with and choice of instrument for each periodontal site, the maintenance of that instrument, and the skill with which the surfaces are debrided as atraumatically as possible.

• The object of calculus removal is to fracture it cleanly away from the tooth surface, not to shave, wear down, or smooth the deposit (referred to as burnishing).

Fig. 4-1

Complications

• Deposit cannot be removed. The solution is to reposition the blade to remove less calculus per stroke, change the angle and direction of pull of the instrument, change instrument, or sharpen the instrument. Too little pressure can cause the instrument to glance over the deposits and to smooth down the deposits rather than remove them. As these deposits become smoother, they also become harder to detect and remove.

• The surface is still rough after planing. The solution is to check the instrument for sharpness and replane or, if too much force has been applied causing an uneven root surface known as ruffling, to use light, smooth strokes.

• Failure to plane the root in the apical portion of the pocket leaves bacterial plaque and causes an increase in periodontal pocketing and subsequent periodontitis and bone loss.

• Some root surfaces do not lend themselves to thorough root planing, including the maxillary first and second molar. In this case, careful instrument selection and adaptation is important. Failing to do this, it is better to perform a periodontal flap procedure or extract the tooth.

• Hemorrhage may limit visibility. Limited visibility may require the use of pressure, water irrigation, and suctioning during the procedure.

• It may be difficult to access the root surface, particularly in areas of exposed furcations that may be large enough to allow accumulation of plaque and calculus, but too small and inaccessible to permit thorough root planing. Microultrasonic instruments may be the solution, due to their thinner tips and type of movement.

• Overuse of instrumentation and aggressive instrumentation cause damage to the gingival fibers or periodontal ligament at the apical end of the pocket.

Aftercare: Follow-Up

• Routine home care (see Chapter 4).

• Antibiotics.

GINGIVAL CURETTAGE

Indications

• Removal of sulcular epithelium, inflammatory infiltrate, subgingival bacteria, and invasive bacteria.

• Debridement of a periodontal abscess.

Objective

• Elimination of the microorganisms that elicit gingival inflammation and of diseased or infiltrated tissues.^18,¹⁹

Equipment

• Ultrasonic scaler with periodontic tip.

• Curette (sharp instruments are important).

Complications

• Excessive destruction of the gingiva.

• Deepening of the periodontal pocket may be caused by placing the curette too deeply into the pocket and tearing or cutting the periodontal ligament or perforating the junctional epithelium at the base of the pocket (Fig. 5-2, C).

• Plaque or calculus left in the pockets—the superficial and coronal tissue heals, and the pocket shrinks and tightens, trapping mineralized bacterial plaque and calculus and resulting in increased chronic lysosomal release, tissue breakdown, bone loss (periodontitis), and possible abscess, which further prevents healing (Fig. 5-2, D). As part of the process, the tissues should be irrigated with water or an antimicrobial irrigant to cleanse the area further.

• Formation of a thick blood clot, which may hinder the adaptation of the gingival tissues to the teeth. Applying gentle pressure until hemorrhage stops may help avoid this.

ULTRASONIC PERIODONTAL DEBRIDEMENT

General Comments

• There has been a paradigm shift from the traditional emphasis on treatment of the tooth and root surface in periodontal therapy to a focus on establishing and maintaining healthy periodontal tissues.

• Removing bacterial plaque and endotoxins and removing plaque-retentive deposits and surfaces are the main goals of periodontal debridement.²⁰

• If plaque is removed thoroughly, periodontal tissues heal in spite of residual calculus deposits.

• This procedure may involve three phases: supragingival debridement, subgingival debridement, and plaque removal.

• This procedure removes less cementum than manual root planing with curettes; this creates less dentinal hypersensitivity and less chance of overinstrumentation and gouging of tooth and root surfaces.

• The long slender tips allow removal of bacteria to the apical limit of the pocket.

• Specialized tips can be used in and around furcations to improve removal of bacterial colonies and calculus, especially in the dome areas of furcations, previously inaccessible.

• This procedure can be performed in pockets greater than 4 mm in a closed fashion.

• This procedure can be performed as an adjunct to open procedures.

• This procedure can be performed more quickly and more effectively, with less anesthesia time and with less effort, than manual root planing.

• It is less technically demanding than root planning with curettes.

• Antimicrobial irrigants (dilute chlorhexidine or povidone-iodine solutions) can be added to the water source of some ultrasonic scalers to aid in plaque reduction and reduction of bacterial aerosolization.

• Ultrasonic bactericidal debridement combines the cavitation effect of the instruments destroying or lysing bacterial cell walls with the antimicrobial lavage.

Indication

• Subgingival dental plaque and calculus.

Contraindications

• Nonsalvageable teeth.

• Depends on general health considerations of the patient (systemic disease and patient’s overall health).

Equipment

• Sonic scaler with long, thin periodontal tip.

• Ultrasonic scaler with specialized thin, micro tips, or inserts (see Chapter 2).

• Probe.

• Explorer.

• Curettes.

Technique

• The patient’s mouth is lavaged with a dilute chlorhexidine solution to reduce external bacterial counts.

• Supragingival calculus and plaque are removed with the broad tips and with light, rapid sweeping motions over the surface of the crown.

• The ultrasonic or sonic scaler is fitted with the long, thin periodontal tip. The power setting is reduced and tuned properly, and the water spray is adjusted.

• The instrument tip is used similarly to a probe, placed in the sulcus or pocket parallel to the long axis of the tooth surface.

• The side of the tip of the instrument is used with a paintbrush-like motion over the root surface in diagonal strokes. The pressure is very light and rapid strokes are used (also referred to as feather-light touch).

• Removal of subgingival calculus starts coronally and works apically, using the end of the tip in a gentle tapping motion against the calculus to shatter and remove it.

• After calculus removal, the tip is used in a broad sweeping motion in the sulcus or pocket, to remove bacteria from the tooth surface. The instrument tip must touch every square millimeter of root surface; therefore, overlapping or cross-hatching strokes are most desirable.

• A curette or explorer is used to evaluate the smoothness of the root surface, because these delicate instruments provide an excellent tactile evaluation.

• High-speed suction should be used, if available, to remove water buildup and reduce aerosolization. If suction is unavailable, the patient’s head should be tipped down over a grate or laid on a towel to keep water from collecting under the patient.

Aftercare: Follow-up

• Follow routine home care instructions (see Chapter 4).

• Recall is scheduled according to the severity of the condition.

PERIOCEUTIC TREATMENT

Indication

• Patients with periodontal pockets equal to or greater than 4 mm; for treatment after root planing or periodontal debridement therapy.

Contraindications

• Lack of thorough periodontal therapy.

• Age less 1 year, because tetracycline products may cause discoloration of teeth.

Objective

• To infuse the material into the periodontal pocket to allow for a 2- to 4-week release of antibiotic into the periodontal pocket.

Materials

• Doxycycline 8.5% (Doxirobe, Pfizer, New York, NY). This product comes in a packaged pouch with two syringes and a 23-gauge, 1-inch blunt cannula. Once mixed, the product becomes a solution of doxycycline hyclate equivalent to 8.5% doxycycline activity.

• Plastic working instrument.

Technique

• Periodontal therapy with root planing or periodontal debridement should be performed. The root surface and pocket should be completely free of calculus, plaque, and other debris. The product should be applied only after the teeth and pocket are clean.

Step 1—The two syringes are locked together.

Step 2—Beginning with syringe A, express the contents into syringe B, mixing the product by pushing the syringes back and forth approximately 100 times until the contents are mixed completely.

Step 3—Deliver all of the contents of the syringes, and remove syringe B from A and replace with the supplied 23-gauge cannula.

Step 4—Gently place the cannula 1 to 2 mm below the gingival margin of the tooth to be treated, and inject the mixture while moving the cannula in the pocket. The pockets should be filled to the gingival margin.

Step 5—Lavage with a few drops of water supragingivally to hasten the solidification of the material.

Step 6—As the material hardens, the product that is exposed supragingivally may be pressed into the pocket with a plastic working instrument or back of a curette.

Complication

• Loss of the material out of the pocket; in this case, the material may be tapped into place with a plastic working instrument.

Aftercare: Follow-Up

• Because the product is biodegradable, removal is not required.

• Continued home care is important.

PERIODONTAL SURGERY

• Various modalities may be employed when performing periodontal surgery. The time-honored and traditional modality of scalpel surgery, using various sizes and shapes of scalpel blades, is the most commonly used modality. Electrosurgery and radiosurgery have been used frequently in recent years. More recently, laser surgery has been touted as a “painless” surgical technique and a way to perform high-technology surgery. There are pros and cons for each modality. Laser units are expensive and, in the opinion of the authors, in most instances do not offer significant advantage over scalpel and electrosurgical techniques to justify the increased cost to the clinic and the client. Surgical procedures in this text will be described with scalpel surgery, because that is what is employed in most veterinary offices. Readers who prefer other surgical modalities should substitute the use of scalpel with that of their own instruments. Following are brief descriptions of the three modalities and the advantages and disadvantages of each.

Electrosurgery and Radiosurgery

• Compared with electrosurgery, electrocautery uses low frequency, low wattage, and low heat, which creates incandescent heat, causing a third-degree burn that is harmful to tissues and can cause bone loss.

• Electrosurgery uses a frequency of 2.0 MHz or higher. Radiocautery uses higher frequency (3.0 to 4.0 MHz) and is relatively atraumatic.²¹ Fully rectified filtered waveform is used for cutting soft tissue with a pure continuous flow of high-frequency energy to provide micro-smooth cutting. There is minimal amount of lateral heat, and it can be used close to bone. Partially rectified waveform is used for coagulation of soft tissue, desensitizing dentin and cementum from cervical erosions, bleaching endodontically treated teeth, and drying and sterilizing endodontic canals.²²