Introduction to Pet Dental Care, An

For Veterinary Nurses and Technicians

Kathy Istace

• Publisher: CAB International
• Year: 2021
• Print ISBN:
  9781789248869
• eBook ISBN:
  9781789248883
• Topic: Medicine
• Subtopic: Veterinary Medicine

Periodontal disease is one of the most common diseases observed by small animal practitioners, and it is not uncommon for the veterinary technician to be the first line in oral health assessment and treatment. Despite this, current dentistry training for veterinary technicians and nurses is often very limited. This book explains the causes, consequences, prevention and treatment of pet dental diseases including periodontal disease, fractured teeth, tooth resorption, dental malocclusions, oral masses, jaw fractures, and other oral conditions. It covers: · Instruction in essential skills such as dental cleaning, charting, radiography, and equipment maintenance.· Advanced skills such as the administration of regional nerve blocks and periodontal treatments.· The aetiology and treatment of common oral conditions. Improving competence in veterinary dental skills benefits technicians, veterinary practices, owners and their pets. Explaining pet dental diseases in a relatable way, this book allows veterinary staff to relay important dental information to pet owners in a way they understand. Providing solutions to help prevent and manage pet dental diseases, it outlines treatment options, outcomes, and post-operative dental care.

1

More than Just Bad Breath: Periodontal Disease

© CAB International 2022. An Introduction to Pet Dental Care: For Veterinary

Technicians and Nurses (K. Istace)

DOI: 10.1079/9781789248869.0001

‘Doggy breath’ (and kitty breath, too) is such a common problem that most pet owners accept it as normal. It isn’t! Bad breath is usually the first sign of one of the most common preventable diseases afflicting pets today: periodontal disease (Perrone et al., 2020). By 2 years of age, 80% of adult dogs and 70% of adult cats have periodontal disease (Niemiec et al., 2020), which means that nearly every patient seen in a veterinary practice needs dental care. Periodontal disease is a progressive condition that can be prevented with proper dental homecare and regular professional dental cleanings, but once a patient develops the disease, it can often only be managed, not cured (Bellows et al., 2019). The American Animal Hospital Association recommends annual dental cleanings starting at 1 year of age for cats and small-breed dogs, and starting at 2 years of age for large-breed dogs (Bellows et al., 2019).

1.1 Dental Anatomy and Periodontal Disease

We divide teeth into two parts: the crown, which is the portion of tooth above the gumline which functions to hold, tear, and chew; and the root, which anchors the tooth into the surrounding bone (Holzman, 2020). The crown is covered with a thin (<0.03–0.6 mm) layer of enamel (see Fig. 1.1): a hard, non-porous substance composed primarily of the mineral hydroxyapatite (Hale, 1997). The root is covered by a hard tissue called cementum. The crown and root meet at the cementoenamel junction (CEJ), commonly called the ‘neck’ of the tooth (Holzman, 2020). Beneath both the enamel and cementum is dentin, which contains more organic material than enamel and is porous, with hollow channels called dentinal tubules that provide the dentin with nutrients from the pulp. Dentin is continually produced by cells called odontoblasts throughout an animal’s life. As an animal matures, more dentin is produced. This causes the pulp chamber, an area of nerves and blood vessels contained in the crown, to narrow and the tooth to become stronger. Gradual tooth wear can stimulate the formation of reparative dentin to protect the tooth from pulp exposure (Hale, 1997).

At the centre of the tooth is the endodontic system, which contains the tooth’s blood supply and nerves, and enters the tooth through the apex (base) of the root. The endodontic system is also divided into two parts: the pulp chamber within the crown, and the pulp canals within the root (Holzman, 2020).

Periodontal disease is the inflammation and infection of the periodontium: the tissues surrounding the teeth (Harvey, 2005). This inflammation and infection leads to tooth loss. There are four types of periodontal tissues (Hale, 1997; Stepaniuk, 2006; Holzman, 2020):

1. Gingiva (gums): soft tissue surrounding the teeth. It is the periodontium’s first line of defence against harmful pathogens. It is comprised of the free gingiva, which is not attached to the tooth, and the attached gingiva, which is attached to the CEJ. The space between the free gingiva and the tooth is known as the gingival sulcus, containing sulcar fluid that includes antibodies and white blood cells. The gingiva is connected to the looser alveolar mucosa at the mucogingival junction.

2. Cementum: tissue similar to bone that covers the tooth roots, serving as a point of attachment for periodontal ligament fibres. It is continually deposited and resorbed throughout an animal’s life.

Fig. 1.1. Dental anatomy.

Click to see the long description.

3. Periodontal ligament: holds the tooth within its socket and acts a as shock absorber during chewing.

4. Alveolar bone: surrounds a tooth’s roots, and contains blood vessels, nerves and lymphatic vessels.

1.1.1 Pathophysiology of periodontal disease

Periodontal disease begins with plaque (Barthel, 2006). Plaque development occurs similarly in humans and other mammals (Gorrel, 2004). Saliva, a liquid secreted by the salivary glands to lubricate the mouth and aid in digestion, forms a coating on the teeth called the pellicle (Harvey, 2005). Within a few hours, several hundred strains of bacteria normally present within the oral cavity, such as Actinomyces and Streptococcus species (Eisner, 2006), start to colonize the pellicle, feeding on amino acids, proteins and glycoproteins within the saliva (Niemiec et al., 2020). This bacteria-laden coating is known as dental plaque: a soft, sticky biofilm that adheres tenaciously to the tooth’s surface (Perrone et al., 2020). In addition to bacteria, plaque is composed of epithelial cells, white blood cells, macrophages, and salivary glycoproteins (Gorham, 2006). Plaque is usually invisible, but heavy plaque deposits may appear as a grey or white soft material on the tooth’s surface. Once attached, plaque can only be removed from the teeth by mechanical scrubbing such as brushing, abrasive diets, or professional dental cleanings (Perrone et al., 2020).

At first, plaque is confined to the tooth’s crown, and contains predominantly non-motile, aerobic cocci (Lobprise and Wiggs, 2000a). When these cocci contact the gingiva, they stimulate an inflammatory response (Holmstrom et al., 2000). White blood cells engulf the bacteria and burst when full, releasing toxins and enzymes that irritate the animal’s periodontal tissues, causing an inflammation of the gums called gingivitis. The gingiva reddens and swells as it increases its blood supply in an attempt to fight off the invading bacteria. As the gum tissue swells, it loses its ability to cling tightly to the tooth’s surface, creating a space between the tooth and the gingiva known as a periodontal pocket. Periodontal disease is considered to be present when pocket depths are greater than 3 mm in dogs and 1mm in cats. Plaque can now begin to creep beneath the gumline, and bacteria can freely attack the tissues that hold the tooth in the mouth (Holmstrom et al., 2000). The bacteria also secrete substances that improve the biofilm’s adhesion to the tooth and protect the bacteria from antimicrobial agents; bacteria found within plaque can be more than 1000 times more resistant to antiseptics and antibiotics than the same bacteria would be by itself (DuPont, 1997).

Once oxygen is no longer able to reach the deepest layers of this thick matrix, the bacterial population begins to shift, with anaerobic, mobile bacilli and filamentous organisms such as Porphyromonas, Prevotella, Bacteroides, Fusobacterium and Treponema taking over (Gingerich, 2012; Niemiec et al., 2020). These anaerobes produce endotoxins which, along with the patient’s own defence mechanisms, lead to soft tissue loss (Lobprise and Wiggs, 2000a; Perrone et al., 2020) or, sometimes, gingival hyperplasia, an overgrowth of gum tissue that occurs secondary to chronic inflammation (Barnette, 2020).

If plaque is not removed, within 24–72 hours calcium carbonate and calcium phosphate salts within the saliva begin to mineralize into a hard substance called calculus or tartar (Clarke, 1999; Perrone et al., 2020). Calculus itself doesn’t cause periodontal disease, but it is thick, rough, and porous, allowing bacteria to proliferate within and beneath it (Gorrel, 1998). It is firmly attached to the tooth and can only be removed by mechanical means such as dental scaling with hand instruments or ultrasonic scalers (Perrone et al., 2020). Calculus deposits can become so large that they displace and damage the gingiva.

As the gum tissue is destroyed, it begins to recede, exposing the tooth root. The infection can create periodontal pockets so deep that the ligament holding the tooth within its socket, and even the bone of the socket itself, are also destroyed (Bellows et al., 2019; Niemiec et al., 2020).

1.1.2 Health problems associated with periodontal disease

Oral pain, bleeding gums and tooth loss are obvious consequences of untreated periodontal disease (Holmstrom et al., 2000). Less obvious, though serious, consequences also exist.

• Oronasal fistulas occur when severe periodontal disease affects the upper canine teeth, whose roots are separated from the nasal cavity by only a thin shelf of bone that is easily destroyed by infection. This leads to communication between the oral and nasal cavities and results in sinusitis (Lobprise and Wiggs, 2000a). This is very common in older, small-breed dogs such as miniature Dachshunds (Perrone et al., 2020).

• Pathologic jaw fractures can be caused by severe bone loss due to periodontal disease in the lower jaw, most commonly around the roots of the lower first molar in small-breed dogs. In these cases, dogs have been known to fracture their jaws while eating, playing with toys or other dogs, or while having diseased teeth extracted (Niemiec et al., 2020).

• Osteomyelitis, an area of dead, infected bone, can also be a result of severe periodontal disease (Niemiec, 2004). Osteomyelitis typically does not respond well to antibiotic therapy and may require surgical removal of part or the entire upper or lower...

Table of contents

• Cover
• HalfTitle
• Title Page
• Copyright
• Introduction
• 1. More than Just Bad Breath: Periodontal Disease
• 2. Comprehensive Oral Health Assessment and Treatment (COHAT); Dental Instrument Use and Maintenance
• 3. Dental Essentials: Dental Charting, Dental Radiography and Pain Management
• 4. If It’s Broke, Fix it! Tooth Fractures, Discoloured Teeth, Abrasion and Attrition
• 5. The Hole Problem: Tooth Resorption and Caries
• 6. Out of Place: Malocclusions
• 7. Lumps and Bumps: Oral Masses and Cysts
• 8. Seeing Red: Stomatitis, Feline Juvenile Gingivitis and Contact Mucositis
• 9. Bad to the Bone: Jaw Fractures, Temporomandibular Joint (TMJ) Luxation, and Avulsed and Luxated Teeth
• 10. Common Dental Problems of Rabbits, Rodents and Other Small Mammals
• 11. Gaining Client Compliance, Dental Estimates, and the Dangers of Anaesthesia-free Dentistry
• 12. Admitting, Preparing and Recovering Dental Patients; a Day in the Life of a Pet Receiving a COHAT
• 13. Sending them Home: Postoperative Care
• 14. Developing Dental Homecare Programmes; How to Brush the Teeth of Dogs and Cats
• 15. Understanding the Science Behind Dental Homecare Products
• 16. Advocating for Pet Dental Health
• Index