Tài liệu FELINE DENTISTRY Oral Assessment, Treatment, and Preventative Care_2 docx

High/Low Speed Delivery Systems Compressed air or gas can be used to power handpieces for polishing, tooth sectioning, endodontics, restoration, and oral surgery.. Rotary Cutting Instr

Treatment

Section II

• Dental models (fi gs 6.10 a,b,c)

Oral Treatment and Prevention Instruments and Materials

Acquiring the proper equipment to perform feline

den-tistry is one of the wisest investments a practitioner can

make There is no other branch of small animal practice

wherein a relatively modest fi nancial investment can

provide such benefi t to the patient, client, and practice

(fi g 6.1 )

Choosing how much equipment, materials, and

edu-cation to obtain is an individual decision If feline

den-tistry is only a small part of the practice, the veterinarian

may want to acquire only basic equipment and

materi-als If advanced dentistry is the goal, additional

instru-ments, materials, and training are needed

• Veterinary Dentistry: Principles and Practice, Wiggs

and Loprise, Lippincott, 1998

• Small Animal Dental Equipment, Materials, and

Techniques, Bellows, Blackwell, 2004

• An Atlas of Veterinary Dental Radiology, DeForge

and Colmery, Iowa State University Press, 1999

• Atlas of Canine & Feline Dental Radiography;

Mulligan, Aller, and Williams; Veterinary Learning

Systems; 1998

• An Introduction to Veterinary Dentistry; Johnston;

an interactive multimedia CD - ROM dental

educa-tion course comprised of six chapters, including

video clips; www.vetschools.ac.uk

• The Practice of Veterinary Dentistry: A Team Effort,

Bellows, Iowa State University Press, 1999

• Atlas of Dental Radiography in Dogs and Cats,

DuPont and DeBowes, Saunders, 2009

Figure 6.2 a Leopold mouth gag (Cislak) b Proper placement of mouth

gag between canines

a

b

Figure 6.11 a Ultrasonic scaler (Midmark) b Piezoelectric tips

Figure 6.12 Low - speed polishing handpiece with disposable polishing tip

b

Figure 6.16 a and b Extraction forceps (Cislak)

Figure 6.20 Assorted high - speed burs

• Zinc oxide – eugenol or non - eugenol endodontic

canal sealer (Sealapex - Kerr)

Professional calculus and plaque removal (scaling) is

performed by using hand instruments or scalers powered

by electricity, compressed air, or gas while the cat is

anesthetized Powered scalers increase the speed and

effi ciency of teeth cleaning

There are three types of power - driven scalers: sonic,

ultrasonic, and rotary Because of the potential for

iatro-genic damage to the gingiva, dental hard tissues and the

pulp, techniques for rotary scaling are not discussed in

this text

Sonic Scaler

The sonic (subsonic) scaler is attached to the high - speed

outlet of an air - or gas - driven delivery system Sonic

scalers have a wide amplitude (0.5 mm) compared to

remove plaque and fresh calculus Most cats requiring scaling present with chronic calculus and plaque accumulation

The sonic scaler unit requires continuous air pressure

of 40 psi A relatively large compressor ( > 1 hp) is needed for power If the delivery system is oxygen - , nitrogen -

or carbon dioxide – driven, use of sonic scalers can consume large volumes of gas, which might not be

fi nancially feasible Daily lubrication is necessary for maintenance

Ultrasonic Scaler

Ultrasonic scalers are classifi ed as magnetostrictive or piezoelectric Magnetostrictive units use ferromagnetic stacks or ferrite rods to produce tip vibration Ferromag-netic stacks are strips of laminated nickel attached with solder When the operator wants to remove plaque and calculus from above the gingiva, the standard P - 10 or beavertail insert is selected When subgingival use is planned, magnetostrictive thin, long subgingival After - Five (Hu - Friedy) and SLI Slimline (Dentsply Cavitron) inserts can be used safely

When an alternating electrical current is supplied to a wire coil in the magnetostrictive handpiece, a magnetic

fi eld is created around the stack or rod transducer, causing the tip to constrict and relax This vibration energizes the water as it passes over the tip, producing

a scouring effect to remove plaque, calculus, and stains Bubbles are created which implode, affecting bacterial cell walls in the gingival sulcus The water mist also cools the tip and irrigates debris

A piezoelectric scaler is activated by dimensional changes in crystals housed within the handpiece as elec-tricity is passed over the surface of the crystals The resultant vibration produces tip movement (fi g 6.21 ) When choosing an ultrasonic scaler, frequency, tip motion, and potential iatrogenic injury must be consid-ered Magnetostrictive advocates claim elliptical tip motion is most effective because it generates pathogen - destroying cavitation bubbles 360 degrees around the tip In contrast, the piezo design creates bubbles only at the two ends of the back - and - forth cycle The sonic scaler does not produce cavitation bubbles

Frequency

Equipment 161

compares the tip in use with an original A loss of one millimeter of the tip equals a 25% loss of effi ciency A two millimeter loss of the tip equals a 50% loss in effi -ciency and the tip should be replaced

The magnetostrictive types of ultrasonic tips are changed with a pull - out/push - in action O - rings are used in the handpiece and on the instrument to provide

a tight fi t and a seal to prevent water leakage

Piezocelectric scalers require a wrench to unscrew one tip and to replace it with another

Magnetostrictive inserts and piezoelectric tips should

be cleaned and sterilized after each use To clean, rinse thoroughly or immerse in an ultrasonic instrument - cleaning unit for 20 minutes After removal, rinse the inserts with tap water and dry before packaging and sterilizing in a steam autoclave or gas sterilizer

Virtually all brands of magnetostrictive inserts of the same frequencies are interchangeable Most 30 kHz units will operate only with 30 kHz inserts (a 25 kHz insert will not fi t into the handle) Most piezoelectric scalers use tips designed specifi cally for each brand of scaler, which creates a problem if the manufacturer goes out of business

Power Scaling Technique

Follow these steps for the sonic/ultrasonic technique:

1 Hold the handpiece lightly in a modifi ed pen grasp; i.e., the scaler is held in the dominant hand with the pads of the index fi nger and thumb oppo-site to each other on the handle closest to the working end The thumb and index fi nger are not touching, thereby creating a tripod effect with the middle fi nger placed along the shank of the instrument This tripod effect balances the instru-ment in the operator ’ s hand to provide stability and control by keeping the index fi nger and thumb separated

2 The ultrasonic instrument should be grasped lightly, not tightly It should feel balanced in the hand, with minimal pull from the handpiece cord The handpiece, not the hands, must be allowed to

do the work The handpiece is balanced on the index or middle fi nger A modifi ed pen grasp is not

as important in holding the ultrasonic or sonic scaler as it is with hand instruments To decrease stress on the hand from the pull on the handpiece cord, the cord may be looped over the little fi nger (fi g 6.22 )

3 Use eye, ear, and respiratory protection

4 Hold the fulcrum or fi nger rest at a distance further from the tooth than with hand instruments, because the tips do not have cutting edges

Figure 6.21 Piezoelectric ultrasonic scaler

better cavitation is achieved at low power settings if the

scaler is slightly mistuned Because auto - tuned scalers

perfectly tune to the insert ’ s frequency, a manually

tuned scaler would be preferred

Tip Activity and Surfaces

The activity of piezoelectric scalers is limited to the last

3 mm of the tip Magnetostrictive metal stack tips are

active at the last 4 mm of tip; the magnetostrictive ferrite

rod scaler is active a full 12 mm of the tip

The most powerful surfaces of the magnetostrictive

stack scaler tip are the underside and the top; the lateral

sides are the least active To prevent trauma to the tooth

surface, only the lateral sides should be used against the

tooth or within the gingival sulcus The ferroceramic

(ferrite) rod tip is equally active on all sides

Tip Replacement

Tip wear is critical to the effi ciency of the scaling

proce-dure Tip wear can be evaluated using a chart which

162 Feline Dentistry

Figure 6.22 Proper fi nger position

Figure 6.23 Adjusted mist for ultrasonic scaling

High/Low Speed Delivery Systems

Compressed air or gas can be used to power handpieces for polishing, tooth sectioning, endodontics, restoration, and oral surgery The advantages over motorized systems lie in the capability of precise cutting at higher speed, and water cooling to prevent thermal damage to the pulp and surrounding bone

The compressor provides pressurized air for the air water syringe and handpieces Compressor size is important The required capacity of the compressor is related to the number of operatories and handpieces used at the same time in the practice The compressor must be large enough to maintain pressure of 30 – 40 psi

-at a fl ow r-ate of 3 cubic feet per minute When the pressor is too small, it will run almost continuously during use and may overheat If a sonic scaler or more

5 Adjust water spray to deliver a steady drip with a

small mist halo (fi g 6.23 )

6 Apply light pressure to the tip working in a

coro-nal - to - apical direction The sound waves should do

most of the work Effi ciency decreases with

increased pressure

7 Pass the side of the working end over calculus and

plaque in short, light vertical strokes The scaler

should not be used on a single tooth for too long to

avoid iatrogenic damage Heavy lateral pressure

should be avoided

8 Keep the lateral surface working end in constant

motion Leaving it in one place too long increases

the amount of tooth material removed and can

cause thermal damage to the pulp Never hold the

tip perpendicular to the surface of the tooth This

will either etch or groove the surface

Equipment 163

self - contained delivery systems Unfortunately, when

using an oil - cooled compressor, small particles of oil

become mixed with the compressed air, which might

contaminate tooth surfaces, interfering with

restoration

Compressors for dental delivery systems are attached

either to the unit (self - contained) or located remotely

in a nearby cabinet, closet, attic or outside the clinic

The advantages of remote compressors include the

The storage or air tank holds air compressed by the

compressor This stored air is used to power the dental

handpieces and air/water syringe Air tanks come in

many sizes The larger the tank size, the less “ work ” the

compressor needs to do Pressure inside the air storage

tank varies by manufacturer between 80 – 120 psi When

maintenance pressure is reached, the compressor turns

off When the tank pressure drops below 60 psi, the

compressor turns on to refi ll the tank with compressed

air

The assembly delivery system (control panel) contains

the air/water supply syringe, tubing for the handpieces,

pressure gauge(s), switches for turning water on and off,

needle valve to adjust water fl ow and a switch to change

from the high - to low - speed handpiece The control

panel may be part of a cart or mounted on the dental

table (fi gs 6.24 a,b)

The foot pedal starts and stops the system and in some

units controls handpiece speed

Nitrogen - Powered Delivery Systems

Some delivery systems use nitrogen to power

hand-pieces Nitrogen, an inert gas, can provide clean, oil - free

power, which may extend the handpiece life Because

power is directly delivered from gas cylinders,

compres-sors and air storage tanks are not necessary There is no

electrical requirement and no compressor noise

Addi-tionally, nitrogen - driven delivery systems require less

maintenance than air - driven units The typical cost of

nitrogen is less than US$1.50 per procedure Nitrogen is

not recommended to power air - driven sonic scalers

because of the large volume of gas needed (fi gs 6.25 a,b)

A three - way air/water syringe is part of the delivery

system The syringe produces a stream of air, water or

a spray, for rinsing debris from the teeth and drying as

needed during dental procedures (fi g 6.26 )

Dental handpieces are precision - built mechanical devices designed for use with rotary instruments, such

as burs, stones, wheels, and discs Handpieces can be classifi ed according to the revolutions per minute (RPM)

or speed at which they operate Handpieces that run under 100,000 RPM are classifi ed as slow speeds Models running at 20,000 – 100,000 RPM are classifi ed as slow - speed type II mid speed Low speed is a subcategory of slow speed The handpieces commonly used in veteri-nary medicine run less than 20,000 RPM and are classi-

fi ed as slow - speed type III low speeds

The (s)low - speed (straight) handpiece commonly used in veterinary dentistry:

• Rotates at 5,000 – 20,000 RPM

• Contains forward and reverse controls

• Operates with high torque

a

b

Figure 6.24 a Control panel, air/water syringe, handpieces, and ultrasonic scaler (Midmark) b Nitair II (CBi)

b

Figure 6.25 a Nitrogen - powered high - /low - speed delivery system (CBi) b Portable delivery system

Equipment 165

Figure 6.26 Three - way air/water syringe

The disposable plastic single - use prophy angle is preferred by the author because of reduced cross - contamination, lack of maintenance, ease of operation and low expense

The oscillating disposable prophy angle rotates 45 degrees and reverses Advantages of the oscillating dis-posable prophy angle include decreased heat generated

on the tooth surface and less lip hair caught in the ishing cup

High speed handpieces are used when rapid and effi cient cutting of the tooth and/or supporting bone is needed High - speed handpieces are air - powered to 300,000 – 400,000 RPM To avoid overheating, an irriga-tion spray is automatically delivered over the operative

-fi eld When choosing the handpiece style, a pediatric head gives the operator improved access in small animals Some high - speed handpieces have a fi ber - optic light built into the head The light projects a beam from the head of the handpiece directly onto the bur and tooth

High - speed handpieces use friction grip (FG) burs Attaching a bur to the high - speed handpiece is an easy procedure The chuck is tightened by thumb control

or built - in lever or by using a bur - inserting/ - removal tool

Rotary Cutting Instruments

Rotary cutting dental instruments are used to:

• Is available as one - or multiple - section units

The one - section straight handpiece accepts cutting

and polishing burs designated as handpiece ( HP ) An

HP designation means that the cutting or polishing

instrument has a long, straight shaft that inserts directly

into the straight handpiece and is tightened by rotating

the collar clockwise A prophy head, right - angled

hand-piece or contra - angle may also attach to the one - section

unit

The multiple - section, slow - speed handpiece is

com-posed of a low E (European type) speed motor and a

straight nose cone with a reduction gear to drive the

prophy head, right - angled handpiece or contra - angle

Many units have a method of quickly connecting and

disconnecting the motor and attachments

The contra - angle attaches to the slow - speed straight

handpiece to form an extension with an angle greater

than 90 degrees at the working end Angulation

provides better access to the posterior teeth The contra

-angle ’ s main use is powering burs for fi nishing

restorations and Gates Glidden drills for pulp chamber

and root canal enlargement

The head of the contra - angle attachment contains

either a latch or a friction type chuck, into which a dental

bur or other rotary instrument is fi tted Latch - type

con-tra - angles hold the end of the cutting instrument by

mechanically grasping a small groove on the end of the

instrument shaft Right angle ( RA ) designates latch - type

burs Friction grip ( FG ) burs have short, smooth shafts

without retention grooves

• Remove part of the maxilla or mandible

Burs are instruments placed into the dental

hand-piece Burs consist of two parts:

(1) The shaft fi ts into the handpiece

(2) The head is the cutting end

Operative Bur Types

Carbide steel burs (carbides) are used for cutting and are

the most commonly used burs

Diamond points (diamonds) are burs covered with

industrial diamond grit used for crown preparation,

bone smoothing (alveoloplasty), scarifi cation and

shaping teeth (odontoplasty)

Three Types of Bur Shanks

Straight handpiece burs have long straight shanks In

dental supply catalogs, they are abbreviated as SH or

HP

Latch - type burs have notched shanks and are

abbrevi-ated as LA (latch - type angle) or RA (right - angled)

Friction grip burs have smooth shanks, which are

smaller in diameter than HP burs They are used in high

speed handpieces Friction grip burs are identifi ed as

FG, FGS (friction grip surgical) or FGSS (friction grip

short shank used for tight areas and restorations)

Surgical burs have longer (25 mm) shanks used to

reach into deep recesses; restorative burs are shorter

(20 mm)

Bur Shapes and Sizes

Burs come in several sizes, represented by numbers The

lower the number in a series, the smaller the bur head

Round burs are most commonly used to open the pulp

chamber in preparation for endodontic treatment, bone

smoothing and root atomization Their sizes range from

Fissure burs have grooved heads and are useful for sectioning teeth and reducing crown height The sides

of straight fi ssure burs are parallel The sides of taper

fi ssure burs converge toward the tip Fissure burs may also contain cross - cuts along the blades (called cross - cut

fi ssure burs), which act like saw teeth to allow additional cutting ability The size of straight fi ssure burs ranges from 56 – 58L, that of cross - cut straight fi ssure burs from

556 – 558L and that of taper fi ssure burs from 699 – 703 Diamond burs have industrial diamond grit embed-ded into the working surfaces Diamonds are used in many places that carbides the tooth to receive are, and especially in restorative dentistry to prepare the tooth to receive prosthodontic crowns, and to help fi nish com-posite restorations

Trimming and fi nishing burs are designed for pleting restorations, odontoplasty and alveoloplasty The more fl utes on a fi nishing bur, the fi ner will be the

com-fi nish (a 30 - fl uted bur, also known as a com-fi ne com-fi nishing bur, produces a smoother fi nish than does a 12 - fl uted bur) Stones are used for polishing and fi nishing restora-tions Stones are mounted on a mandrel (mounting device), which is inserted into the handpiece Stones are identifi ed by color White stone burs are commonly used

in veterinary dentistry to fi nish composite restorations

or to smooth minor enamel defects Green stones are used to fi nish amalgam and smooth enamel Gray stones, made of carborundum and rubber, are used for polish-ing fabricated crowns

Finishing discs are used to shape and smooth tions They are available in various grades of abrasive-ness, from coarse to superfi ne and are used sequentially from coarse (to shape restorations) to fi ne grade (to smooth surfaces) The fi nest - grade disk is used with a paste

Bur Care

Burs are surgical cutting instruments and should be cleaned and sterilized before each use To remove debris lodged in the bur head, the bur is removed from the handpiece then rinsed, brushed free of debris with a nylon or wire bur brush (or pencil eraser) and soaked in

a cold sterile solution for 24 hours

Equipment 167

A generic lubrication/sterilization process consists of

these steps:

1 At the end of each procedure, scrub the handpiece

with gauze, a sponge, or a brush and cleaning

solu-tion to remove debris

2 Following the manufacturer ’ s instructions, rinse the

handpiece without immersion

3 Dry the handpiece with gauze, paper towel, or air

from the air/water syringe

4 For handpieces requiring lubrication, add three

drops of lubricant to the smaller of the two large

holes (drive air tube) at the connection area Note:

Some handpieces are lubrication - free and will be

destroyed if lubricated; check manufacturer ’ s

instructions

5 Briefl y power the handpiece with the bur inserted to

remove excess lubricant

6 Place the handpiece in an autoclavable envelope

7 Sterilize the handpiece in the autoclave

Replacing the High - Speed Turbine

The turbine is secured in the high - speed handpiece head

by a screwed faceplate After the faceplate is unscrewed

using the manufacturer - supplied tool, the turbine can be

easily replaced

To clean and lubricate the low - speed handpiece and

attachments, use the following steps:

1 Place the working end of the handpiece into a small

bottle of handpiece - cleaning solvent

2 Power the handpiece backward and forward for one

minute

3 Remove the handpiece from the cleaner and wipe

dry

4 Periodically, disassemble the handpiece, using the

special wrench furnished by the manufacturer

5 Following the manufacturer ’ s instructions, place

one drop of liquid lubricant on the neck of the head,

one drop on each gear of the gear and shaft

assem-bly, and three drops into the back end of the angle

Alternatively, place heavy lubricant (petroleum

jelly) on the gears of the handpiece before

reassembly

Compressor Maintenance

Oil - cooled compressors are equipped with a dipstick or

view port to monitor the oil level The owner ’ s manual

should be checked for the recommended replacement oil

if needed Some compressors are “ oil free ” and do not

require oil maintenance

Condensation in the air storage tank accumulates with each use The accumulated fl uid should be drained weekly to monthly depending on use and ambient humidity

Infection Control

Disinfection is the process of destroying microbial life

by placing instruments in a solution (example: Cidex) for a specifi ed period Chemical disinfection does not eliminate all viruses and spores

Sterilization kills all microorganisms The autoclave is

a steam chamber for sterilizing instruments During the sterilization cycle, distilled water fl ows into the chamber and is heated to create steam Because the chamber is sealed, pressure increases to approximately 15 pounds per square inch The increase in pressure causes the heat

of the steam to rise to approximately 250 ° F When the instruments are exposed to this high pressure/steam temperature for 15 minutes or more, sterilization occurs Dental instruments used in the mouth should be sterile After cleaning, instruments can be placed in an autoclav-able see - through sleeve and sterilized

Patient and operator infection control requires the following:

An individual set of sterilized instruments should

be used on each patient Human dentists have developed aggressive infection control procedures in response to spreading HIV and hepatitis among patients and staff Many of these protocols can be adopted in veterinary hospitals for similar reasons Viral and bacterial particles may become lodged in the paste remaining on the head

of the prophy angle and transmitted to the next patient even if the prophy cup is changed Disposable prophy angles or autoclaved metal angles are recommended for all feline patients to prevent spread of feline leukemia virus and feline immunodefi ciency virus Polishing paste

is available in individual cups or in bulk form in a supply container When using the bulk container, the paste should be applied with a new and clean tongue depres-sor to avoid contaminating the container

A mask, gloves, and ear and eye protection should be worn when performing dental care The oral cavity should be rinsed with a 0.12% chlorhexidine solution before oral procedures to reduce the number of bacteria that could enter blood vessels of the patient (bacteremia)

or become aerosolized during power scaling The patient ’ s head should be angled downward to promote drainage

High - speed delivery system fl uid lines can develop a biofi lm of potentially harmful viruses and bacteria Chlorhexidine can be used to fl ush the fl uid lines, thus decreasing the viral and bacterial load

168 Feline Dentistry

Further Reading

Deeprose J Operator safety and health considerations In: Tutt

C , Deeprose J , Crossley D (eds) BSAVA Manual of Canine and

Feline Dentistry , 3rd ed BSAVA , Gloucester , 2007 ; 56 – 66

Gorrel C , Penman S Dental equipment In: Crossley DA ,

Penman S (eds) Manual of Small Animal Dentistry , 2nd ed

BSAVA , Cheltenham , 1995 ; 12 – 18

Harvey CE , Emily PP Small animal dental equipment and

materials , Small Animal Dentistry , Mosby , St Louis , 1993 ;

378 – 400

Holmstrom SE , Frost Fitch P , Eisner ER Dental equipment and

care , Veterinary Dental Techniques for the Small Animal

Practi-tioner , 3rd ed Saunders , Philadelphia , 2004 ; 39 – 129

Lipscomb V , Reiter AM Surgical materials and

instrumenta-tion In: Brockman DJ , Holt DE (eds) BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery BSAVA ,

Gloucester , 2005 ; 16 – 24 Robinson J Dental instrumentation and equipment In:

Tutt C , Deeprose J , Crossley D (eds) BSAVA Manual of Canine and Feline Dentistry , 3rd ed BSAVA , Gloucester , 2007 ;

67 – 76 Wiggs RB , Lobprise HB Dental equipment, basic materials and supplies , Veterinary Dentistry — Principles and Practice ,

Lippincott - Raven , Philadelphia , 1997 ; 1 – 54

gival space between the gum and the root), where odontal disease is active Because the patient cooperates, dental scaling of human teeth performed by a professional trained in the procedures can be completed successfully without anesthesia However, access to the subgingival area of every tooth is impossible in an unanesthetized canine or feline patient Removal of dental tartar on the visible surfaces of the teeth has little effect on a pet ’ s health and provides a false sense of accomplishment The effect

peri-is purely cosmetic

3 Inhalation anesthesia using a cuffed endotracheal tube

provides three important advantages — the cooperation

of the patient with a procedure it does not understand, elimination of pain resulting from examination and treat- ment of affected dental tissues during the procedure, and protection of the airway and lungs from accidental aspiration

4 A complete oral examination, which is an important part

of a professional dental scaling procedure, is not possible

in an unanesthetized patient The surfaces of the teeth facing the tongue cannot be examined, and areas of disease and discomfort are likely to be missed

Safe use of an anesthetic or sedative in a dog or cat requires

evaluation of the general health and size of the patient to determine the appropriate drug and dose, and continual moni- toring of the patient Veterinarians are trained in all of these procedures Prescribing or administering anesthetic or seda- tive drugs by a non - veterinarian can be very dangerous, and

is illegal

Although anesthesia will never be 100% risk - free, modern

anesthetic and patient evaluation techniques used in nary hospitals minimize the risks, and millions of dental scaling procedures are safely performed each year in veteri- nary hospitals

To minimize the need for professional dental scaling

proce-dures and to maintain optimal oral health, the AVDC mends daily dental home care from an early age This should include brushing or use of other effective techniques to retard accumulation of dental plaque, such as dental diets and chew

Anesthesia

Chapter 7

General anesthesia is necessary for the oral assessment,

treatment, and prevention visits The American

Veteri-nary Dental College (AVDC) created a position

state-ment (below) regarding the need for general anesthesia

to provide companion animal dental diagnostics and

therapy (fi g 7.1 )

Non - Professional Dental Scaling (NPDS)

In the United States and Canada, only licensed veterinarians

can practice veterinary medicine Veterinary medicine

includes veterinary surgery, medicine, and dentistry Anyone

providing dental services other than a licensed veterinarian,

or a supervised and trained veterinary technician, is

practic-ing veterinary medicine without a license and shall be subject

to criminal charges

Although the term “ Anesthesia - Free Dentistry ” has been

used in this context, AVDC prefers to use the more accurate

term Non - Professional Dental Scaling (NPDS) to describe

this combination This position statement addresses dental

scaling procedures performed on pets without anesthesia,

often by individuals untrained in veterinary dental

techniques

Owners of pets naturally are concerned when anesthesia is

required for their pet However, performing NPDS on an

unanesthetized pet is inappropriate for the following reasons:

1 Dental tartar is fi rmly adhered to the surface of the teeth

Scaling to remove tartar is accomplished using ultrasonic

and sonic power scalers, plus hand instruments that must

have a sharp working edge to be used effectively Even

slight head movement by the patient could result in injury

to the oral tissues of the patient, and the operator may be

bitten when the patient reacts

2 Professional dental scaling includes scaling the surfaces

of the teeth both above and below the gingival margin

(gum line), followed by dental polishing The most critical

part of a dental scaling procedure is scaling the tooth

surfaces that are within the gingival pocket (the

subgin-170 Feline Dentistry

materials This, combined with periodic examination of the

patient by a veterinarian and with dental scaling under

anes-thesia when indicated, will optimize life - long oral health for

dogs and cats

For general information on performance of dental

proce-dures on veterinary patients, please read the AVDC Position

Statement on Veterinary Dental Healthcare Providers, which

is available on the AVDC website ( www.AVDC.org ) For

information on effective oral hygiene products for dogs and

cats, visit the Veterinary Oral Health Council website ( www.

VOHC.org )

Preanesthetic Evaluation

All anesthetic patients require proper preanesthetic

evaluation including a detailed history, physical

exami-nation, and laboratory testing Patients with preexisting

medical conditions may need further evaluation to

Figure 7.1 Patient anesthetized, temperature control assist Bair Hugger ® ,

Cardell ® monitor, Matrix ® anesthetic unit attached to adjustable height

hydraulic table (Canis Major, Midmark)

hydro-Anesthesia 171

Figure 7.3 Preanesthetic medication

For fractious cats presenting without feline

hyper-trophic cardiomyopathy, a combined dose of

mede-tomidine HCl 0.01 – 0.02 mg/kg, plus buprenorphine

0.01 – 0.02 mg/kg, ketamine HCl 1 – 3 mg/kg, and

butor-phanol tartarate 0.1 mg/kg are mixed in one syringe and

administered IM; for fractious cats with feline

hyper-trophic cardiomyopathy, low - volume medetomidine

(0.005 mg/kg) plus butorphanol tartarate 0.1 – 0.2 mg/kg

plus or minus midazolam HCl 0.2 mg/kg may be

administered

All patients should be individually assessed and a

patient - specifi c anesthetic premedication protocol

devel-oped, as the above are simply examples of typical

pre-medication protocols

Induction

There are many feline anesthesia protocols for the

healthy young to middle - aged cat

Chamber or Mask Induction

Chamber or mask induction should be avoided due to

catecholamine release during the excitement phase from

the struggle against restraint or as a reaction to the

pungent odor of the inhalant anesthetic agent

Propofol

Propofol (2,6 - diisoproylphenol) (3 – 4 mg/kg IV; 3 mg/kg

if opioid is given as a premedicant), with half of the dose

given as a slow bolus over 40 – 60 seconds the rest to

effect, is a nonbarbiturate hypnotic Slightly higher

doses are required for cats than dogs, and recoveries are

longer in cats than dogs when the infusion lasts more

than 30 minutes due to decrease in glucuronide

conjuga-tion Propofol provides no analgesia in the cat Propofol

is a direct myocardial depressant resulting in both

venous and arterial relaxation, thus creating

hypoten-sion This hypotension is well recognized clinically and

must be considered when anesthetizing older or ill patients

Etomidate

Etomidate (0.5 – 1.5 mg/kg IV) is the induction drug of choice for patients that have cardiovascular disease or arrhythmias (except A - V dissociation) because cardiac output and blood fl ow to the kidneys are maintained However, there have been reports of hemolysis in cats after etomidate injection A premedicant (e.g., butorpha-nol IV, SC, IM; diazepam; or midazolam IV) should be administered prior to etomidate administration

Pain Control

Anesthesia protocols linked to pain control (in addition

to local anesthesia) include the following:

• Expected mild to moderate pain – - buprenorphine 0.01 – 0.03 IM, IV sublingually mg/kg plus mid-azolam 0.2 mg/kg, plus 0.0005 – 0.075 mg/kg dexme-detomidine (0.0025 – 0.005 μ g/kg)

• Expected moderate - to high - level pain – - phone 0.1 mg/kg plus midazolam 0.2 mg/kg, plus dexmedetomidine 0.0005 – 0.075 mg/kg (0.5 – 7.5 μ g/kg)

Intubation

All cats placed under anesthesia for oral assessment and treatment must be intubated and the airway secured with an infl atable cuff Topical lidocaine may be applied

to the laryngeal mucosa to facilitate passage of the tracheal tube

The endotracheal tube should be secured before the cuff is infl ated The cuff should be infl ated to a light seal Overinfl ation of the endotracheal cuff must be avoided Subcutaneous emphysema and pneumothorax have occurred during or after anesthesia in cats anesthetized for dental care It is critical that anytime the head is moved from side to side during assessment or dental treatment, the endotracheal tube be disconnected from the anesthesia machine and reconnected after the new position is reached (fi gs 7.4 a, b)

Maintenance

Anesthesia is generally maintained with isofl urane or sevofl urane and oxygen Little isofl urane or sevofl urane

The use of gauze sponges placed in the pharyngeal area

to absorb debris is controversial Danger lies in gauze entering the esophagus and either being vomited after the surgical procedure is completed or ingestion leading

to gastrointestinal obstruction

In the author ’ s opinion, packing the pharyngeal area with gauze is not necessary because the seal pro-vided by the endotracheal cuff is suffi cient to prevent iatrogenic injury secondary to aspiration of surgical debris

Monitoring

a

b

Figure 7.4 a Lateral thoracic radiograph before anesthesia b

Pneumotho-rax, pneumomediastinum, and pneumoabdomen secondary to endotracheal

tube – induced tracheal tear

a

b

Figure 7.5 a Hot Dog ® patient warmer b Bair Hugger ® used below the patient

is metabolized The insolubility of the inhalants allows

for a rapid induction and recovery

Patient body temperature control is necessary Long

anesthetic procedures coupled with the frequent use of

water and the ambient room temperature may create

hypothermia In a risk determination study of 138

anes-thetized cats, 71 (51%) had rectal body temperatures

≤ 35 ° C (95 ° F); the lowest recorded temperature was

28.8 ° C (83.8 ° F) Prolonged anesthesia dramatically

increased the risk of hypothermia In addition to the

Anesthesia 173

Figure 7.6 Wireless monitor with esophageal probe

Figure 7.7 Monitor display (DVM Solutions)

palpebral refl ex The pulse should be palpable and the

perfusion time should be two seconds or shorter

Breath-ing durBreath-ing anesthesia should be even and regular

Electronic monitoring includes electrocardiogram,

blood pressure, pulse oximetry, and end tidal CO 2

Apnea, temperature monitoring, and respiratory rate

are additionally helpful in assessing the cat ’ s response

to anesthesia (fi gs 7.6 , 7.7 )

Medical Conditions Requiring

Tailored Protocols

Renal Disease

Some cats with kidney disease may be dehydrated due

to their inability to concentrate urine The dehydration

should be corrected before anesthesia if possible

Mannitol is particularly useful in well - hydrated atric cats with chronic renal failure (with normal cardiac function) to ensure diuresis The dose of mannitol is 0.25 – 0.5 g/kg IV over 15 – 20 minutes

Anesthesia may be induced with a combination of propofol and diazepam Ketamine and barbiturates should be avoided Maintenance with isofl urane is stan-dard Hypotension should be closely monitored and if present adjusted with crystalloid administration

Hyperthyroidism

Chronic unregulated hyperthyroidism can result in cats that present thin, azotemic, with hypertrophic cardio-myopathy, and with multiple oral issues, including tooth resorption, oropharangyeal infl ammation, and periodontal disease If possible, patients should be euthyroid before anesthesia Patients with enlarged hearts on thoracic radiographs should have echocardio-grams performed before anesthesia

Anesthesia protocol in the controlled hyperthyroid cat should be tailored to prevent catecholamine release, avoid arrhythmias, and promote normal blood pressure Premedication with an opioid is advised due to its calming effect and minimal cardiovascular compromise Midazolam, etomidate, and diazepam are considered safe to use for induction

Ketamine should be avoided Barbiturates may also increase heart rate and should not be used Propofol, a generally accepted premedication in the healthy patient, can also impair myocardial function in the ischemic myocardium and should be used with caution

Patient monitoring during anesthesia is critical, cially with regard to blood pressure measurement and ECG Hypotension can usually be managed with proper intravenous fl uid administration without overload Patients with hypertrophic cardiomyopathy have decreased compliance and ventricular volume Dopa-mine administration may be useful to increase blood pressure to ensure adequate renal perfusion Cardiac tachyarrhythmias may be managed with propanolol

Diabetes Mellitus

Diabetes mellitus requires special consideration in the feline dental patient Anesthesia should be scheduled in the morning to avoid normal diurnal fl uctuations of blood glucose levels The client should be instructed to give the patient only half the normal amount of insulin the day of surgery

Unless the cat has secondary organ compromise, generally there are no specifi c medications to avoid for induction or anesthetic maintenance Diabetes can lead to neutrophil dysfunction and impaired wound

• Less immediate postoperative analgesic medication needed

• Improved level of anesthesia, thus decreasing the variation of anesthetic depth when painful stimula-tion occurs

Indications for Local and Regional Anesthesia

• Jaw fracture repair

• Vital pulp therapy

• Periodontal procedures including fl aps, tomy, and oronasal fi stula repair

• Oral mass incision or excision

Contraindications for Local and Regional Anesthesia

healing Intravenous antibiotics (ampicillin) can be

administered at induction and six hours later if surgery

is performed

Blood glucose levels should be monitored at least

every thirty minutes Adjustment with either

intrave-nous glucose or insulin should be administered to

maintain blood glucose concentrations between 100

and 200 mg/dL Periodic blood glucose monitoring

after recovery is also recommended until the patient is

stable

Local/Regional Anesthesia

Pain management must be instituted when approaching

the feline surgical patient General anesthesia is not

suf-fi cient to control dental pain Local and regional

anes-thesia not only help decrease pain before, during, and

after surgery, but also result in less inhaled general

anes-thesia due to decreased hyperventilation

Regional Analgesia

A similarity exists in the way dogs, cats, and humans

feel dental pain Regional anesthetics are agents that

when injected decrease or halt nerve conduction in a

limited area of the body

Regional anesthesia occurs after depositing an

appro-priate agent in close proximity to a nerve innervating the

area intended for dental treatment Following the

injec-tion, anesthetic molecules move by diffusion into the

nerve, blocking its normal action Local anesthetics work

by inhibiting the infl ux of sodium ions into the nerve

axon, preventing the development of the action

poten-tial necessary for sensory propagation along the axon

The loss of sensation can be complete when properly

administered

The trigeminal nerve is responsible for the sensory

innervation of the oral cavity The maxillary teeth, as

well as maxillary soft and hard tissues, are innervated

by the maxillary nerve, which branches into the

infraor-bital nerve The mandibular nerve branches into the

lingual nerve, which innervates the tongue and the

infe-rior alveolar nerve, which branches into the mental

nerves

To obtain complete anesthesia following an injection,

the nerve must be permeated by a suffi cient

concentra-Anesthesia 175

The infraorbital foramen lies as a depression in the alveolar mucosa apical to the distal root of the maxillary third premolar The distal extent of the infraorbital canal can be estimated by palpating the caudal ventral margin

of the bony orbit Advance the needle rostrocaudal izontal) to the entrance of the foramen Before injection, aspirate the syringe in several directions to make sure the tip is not located intravascular

To desensitize caudal to the maxillary fourth premolar

on the same side of the injection, advance the 0.63 - inch needle through the infraorbital foramen and several mil-limeters into the infraorbital canal 50% more anesthetic (not to exceed 2 mg/kg) is slowly injected for 30 – 60 seconds After injection, digital pressure is applied over the foramen for 1 minute to force the agent to diffuse caudally into the infraorbital canal (fi gs 7.8 a, b, c) This block will not likely anesthetize the maxillary molar located 3 – 4 mm caudal to the injection site

Maxillary n erve b lock

The maxillary nerve block desensitizes the palatal soft tissues, dentition, lip, and bone on the injection side of the maxilla

The middle and caudal maxillary alveolar nerves enter the maxilla on the ventral fl oor of the orbit and innervate the molar and premolar teeth To adequately block these nerves, the anesthetic agent needs to be introduced in the rostroventral aspect of the orbit into the pterygopalatine fossa, with an approach from the ventral orbital rim The injected area is rich in neurovas-cular structures supplying the eye For this reason the infraorbital block is preferred

With the cat ’ s mouth open, palpate the zygomatic arch where it meets the maxilla between the fourth premolar and molar Direct the needle next to the bone and advance dorsally along the caudal aspect of the notch to

a level just beyond the root tips Aspirate the needle and slowly inject the anesthetic agent (fi g 7.9 )

Middle m ental n erve b lock

The middle mental nerve block anesthetizes the lingual and buccal soft tissues of the mandibular incisors and canine on the side injected, as well as the third premolar when the needle contents are deposited inside the foramen If the anesthetic agent is deposited outside of the foramen, only the buccal soft tissues from the canine forward to the midline will receive analgesia

Locate the middle mental foramen in the center of the space between the mandibular canine and third premo-lar, then half the distance between dorsal and ventral borders of the mandible under the lip frenulum Insert the needle through the foramen aspirate and inject (fi gs 7.10 a, b)

thesia, decrease systemic toxicity by lowering the blood

concentrations of the anesthetic, and decrease local

bleeding at the injection site

Local and Regional Anesthesia Equipment

Disposable 1 - cc tuberculin syringes equipped with a

0.75 - or 1.5 - inch, 27 - gauge needle are most commonly

used, although human dental local anesthetic

adminis-tration syringes that allow one - hand aspiration can also

be used in cats

Dosage

A combination of 0.5% bupivacaine hydrochloride with

epinephrine (Marcaine ® , 1 mg/kg) and lidocaine 2%

(1 mg/kg) in a 4:1 ratio is commonly used in veterinary

dentistry Mixing 0.8 mL of bupivacaine with 0.2 mL of

lidocaine in the same tuberculin syringe accomplishes

the 4 : 1 ratio The recommended volume for regional

anesthesia is 0.1 – 0.3 mL per injection site Maximum

patient dosage of this mixture would be 0.1 mL/kg, or

approximately 0.25 mL/jaw quadrant in case all

quad-rants need anesthesia in a 5 - kg cat

Injection Precautions

Injection into a blood vessel can alter cardiac function

To be careful that the solution is not being injected

into a vessel, the operator needs to aspirate before

injecting

Nerve Blocks

Desensitization of the teeth occurs mainly through the

pulp Regional anesthesia is obtained by injecting the

anesthetic solution in the proximity of the nerve trunk

Infraorbital n erve b lock

Branches of the infraorbital nerve supply sensory

inner-vation to the maxillary dental arcade The caudal

maxil-lary alveolar nerve, which branches off the infraorbital

nerve before it enters the infraorbital canal, innervates

the caudal maxillary teeth Within the infraorbital canal,

the middle maxillary alveolar nerve branches to supply

the middle maxillary teeth The rostral maxillary

alveo-lar nerve branches off the infraorbital nerve just before

its exit from the infraorbital canal This branch supplies

innervation to the maxillary canine teeth and incisors

The infraorbital artery and vein travel with the

infraor-bital nerve within the canal and should be avoided when

injecting the local anesthetic agent Regional anesthesia

placed deep in the infraorbital foramen desensitizes the

maxillary premolar, canine, and incisor teeth on the

same side of the injection

Infraorbital Foramen

Mental Block Middle Mental Foramena

Figure 7.8 a – c Infraorbital nerve block

Anesthesia 177

Systemic Analgesia

During dental procedures, cats experience pain similar

to that of humans, and they need to have their pain controlled In pain management, the choice of medication varies depending on the anticipated level of discomfort

The opioid family of medication is recommended for controlling dental pain in cats When oral surgery is planned, use of an opioid in premedication, as well as intraoperatively, will provide pain control while waiting for the regional nerve block to take effect

Butorphanol has a duration of effect for pain control

of 1 – 2 hours, oxymorphone 1.5 – 3 hours, and morphine

2 – 4 hours Morphine is unpredictable in its onset of effect and duration of action This may be due in part to the cat ’ s low capacity for hepatic glucuronidation Post-operatively, the author prefers oral buprenorphine, which provides 8 – 10 hours of analgesia

Constant Rate Infusion (CRI)

CRI is being used more widely to provide analgesia both intraoperatively and perioperatively CRI avoids the peaks and troughs in the plasma levels when the medi-cations are given as repeated injections The aim of the infusion is to maintain the plasma level of the drug within the therapeutic range

In order to perform a CRI, an opioid is selected and the dose calculated for a specifi c period of time The total dose is then drawn up into a syringe and administered over time using a syringe pump; or it is added to a volume of fl uids, and then the fl uids are administered

at a specifi c rate for the desired period of time

Mandibular n erve b lock

The mandibular branch of the trigeminal nerve exits the

foramen ovale, dividing into the anterior and posterior

branches The posterior divides into the lingual and

mandibular nerves The mandibular nerve reenters the

mandibular foramen on the medial surface just rostral

to the angle of the mandible to occupy the mandibular

canal

The mandibular nerve can be anesthetized by

intra-oral or extraintra-oral techniques The mandibular nerve is

located 0.5 – 1 cm from the ventral border of the

mandi-ble The mandibular nerve block will desensitize the

mandibular body, the lower portion of the mandibular

ramus, all mandibular teeth on the same side, the fl oor

of the mouth, the rostral two thirds of the tongue, the

gingiva on the lingual and labial/buccal surfaces of the

mandible, and the mucosa and skin of the lower lip and

chin

When using the intraoral approach, infi ltrate the

man-dibular nerve where it enters the mouth at the angle of

the jaw Gently “ walk ” the needle along the medial

border of the mandible just caudal to the last molar

Then advance the needle toward the angular process to

an area half the dorsoventral width of the mandible

Aspirate the syringe, then deliver the anesthetic agent at

the location of the mandibular foramen

When using the author - preferred transcutaneous

(extraoral) approach, clip and prepare a small area of

skin ventromedial to the angle of the mandible just

rostral to the angular process Insert the needle at a

point ventral to the lateral canthus Direct the tip

medi-ally along the border of the mandible Aspirate the

syringe, then slowly inject the anesthetic agent (fi gs 7.11

Anesthesia 179

Techniques for setting up a CRI involve the use of a

syringe pump or a fl uid pump, and the drug to be used

is administered slowly at the bottle concentration or

diluted in maintenance fl uids During surgery, it is

rec-ommended that the drug be administered separately

from the maintenance fl uids since fl uid boluses are

com-monly used under anesthesia to treat hypotension and

blood loss

A CRI commonly used is a combination of

butorpha-nol and ketamine that can be infused continuously (e.g.,

12 mg butorphanol and 60 mg ketamine in one liter of

lactated Ringer ’ s solution given at 1 – 2 mL/kg/hr) The

CRI can be continued after surgery is completed in order

to ease recovery

Transdermal Pain Patch

Fentanyl delivered transdermally through an adhesive

patch will also help to control pain A 25 μ g/h patch is

recommended for small to medium sized cats The patch

should be placed in a location where the patient or small

children cannot access it, and covered with a bandage

The patch can be applied the evening before surgery to

ensure serum levels are appropriate preoperatively

Time from application of a patch to onset of analgesia

is approximately 6 – 8 hours, with maximum effect at 12

hours The patch may stay applied for up to 4 days

Butorphanol should not be used while waiting for onset

of analgesia from the fentanyl patch, as it is a

competi-tive antagonist and will decrease the patch ’ s effeccompeti-tive-

effective-ness In addition, warming devices may accelerate

fentanyl ’ s absorption (fi g 7.12 )

Figure 7.12 Fentanyl transdermal patch

Table 7.1. Analgesic and anesthetic medications

Medication Dosage

Bupivacaine 1 – 2 mg/kg regional block Buprenorphine 0.005 – 0.03 mg/kg q 6 – 8 h SC, IM, IV, sublingual q 6 – 12 h Butorphanol 0.2 – 0.4 mg/kg SC, IM, IV q 2 – 4 h

0.5 – 1 mg/kg orally q 6 – 8 h Carprofen 1 – 4 mg/kg SC, preoperatively, then 2 mg/kg orally limit

two days Codeine 0.5 – 2.0 mg/kg orally q 6 – 12 h Fentanyl 25 μ g/kg/h transdermal patch

Loading dose 1 – 2 μ g/kg IV, then CRI 1 – 4 μ g/kg/h IV Gabapentin 3 mg/kg orally q 24 h

Hydromorphone 0.02 – 0.05 mg/kg SC, IM, IV q 2 – 6 h Ketamine Loading dose 0.2 – 0.5 mg/kg IV, then CRI 10 – 20 μ g/kg/

min IV during surgery, then 2 μ g/kg/min after surgery for up to 18 hours (60 mg ketamine in 1000 mL of Lactated Ringers Solution given at 2 mL/kg/h) Ketoprofen 1 – 2 mg/kg IM or SC once, then 0.5 – 1 mg/kg PO, SC q

24 h for a maximum of 5 days Lidocaine Maximum 2 mL total dose (0.25 – 0.5 mg/kg slow IV) Medetomidine 1.0 μ g/kg with equal volume of butorphanol IV

(producing heavy sedation and not recommended if planning on proceeding to general anesthesia) Before surgery with atropine + opiate: 5 – 10 μ g/kg IM After surgery used alone: 4 – 8 μ g/kg IM

After surgery with opiate: 2 – 4 μ g/kg IM (After surgery, opiate is given at one - half the dose used

in premedication; e.g., butorphanol at 0.2 – 0.4 mg/kg in premedication is used at 0.1 – 0.2 mg/kg after surgery) Meloxicam 0.3 mg/kg SC once

0.2 mg/kg orally q 24 h × 1 day, 0.1 mg/kg PO q 24 h × 2 days (extra - label)

Morphine 0.05 – 0.2 mg/kg SC, IM q 4 – 6 h

0.02 – 0.1 mg/kg IV q 1 – 4 h Postoperatively, CRI 0.1 – 0.3 mg/kg/h (morphine is delivered in 3 – 4 mL/kg/h fl uids)

Oxymorphone 0.05 – 0.1 mg/kg SC, IV, q 1 – 3 h Piroxicam 0.3 mg/kg PO q 24 – 72 h for a maximum of 7 days Tramadol 4 mg/kg orally q 12 h

Postoperative Analgesia

Buprenorphine is an effective opioid for pain control in the cat The small volume, ease of administration, and lack of undesirable side effects make it suitable for home administration The buccal or transmucosal route results

in an onset of action in 20 – 30 minutes and a duration of

8 – 12 hours

180 Feline Dentistry

Mitchell SL , McCarthy R , Rudloff E , Pernell RT Tracheal rupture associated with intubation in cats: 20 cases (1996 – 1998) J Am Vet Med Assoc 2000 ; 216 : 1592 – 1595

Reuss - Lamky H Administering dental nerve blocks J Am Anim Hosp Assoc 2007 ; 43 : 298 – 305

Richey M Anesthesia and pain management in dental and oral procedures In: Holmstrom SE , Frost Fitch P , Eisner ER (eds)

Veterinary Dental Techniques for the Small Animal Practitioner ,

3rd ed Saunders , Philadelphia , 2004 ; 601 – 624 Robertson SA , Lascelles BDX , Taylor PM , Sear JW PK - PD modeling of buprenorphine in cats: intravenous and oral transmucosal administration J Vet Pharmacol Therap 2005 ;

28 : 453 – 460 Rochette J Regional anesthesia and analgesia for oral and dental procedures Vet Clin North Am Small Anim Pract

2005 ; 35 : 1041 – 1058 Silva MLA , Santana MI , Araujo LV , Elston F Topography and anesthetic blockage of mandibular nerve in cats Rev Port Cienc Vet 2006 ; 101 : 187 – 192

Woodward TM Pain management and regional anesthesia for the dental patient Top Comp Anim Med 2008 ; 23 : 106 – 114 Zetner K , Rausch WD , Weissensteiner J , Kruzik P , Steurer I Pain relief after dental treatment in cats Praktische Tierarzt

1996 ; 77 : 678 – 682

Further Reading

American College of Veterinary Anesthesiologists Suggestions

for monitoring anesthetized veterinary patients (available at

www.acva.org/professional/position/monitor.htm )

Beckman BW Pathophysiology and management of surgical

and chronic oral pain in dogs and cats J Vet Dent 2006 ; 23 :

50 – 60

Hale FA , Anthony JMG Prevention of hypothermia in cats

during routine oral hygiene procedures Can Vet J 1997 ; 38 :

297 – 299

Hardie EM , Spodnick GJ , Gilson SD , Benson JA , Hawkins EC

Tracheal rupture in cats: 16 cases (1983 – 1998) J Am Vet Med

Assoc 1999 ; 214 : 508 – 512

Holmstrom SE , Frost Fitch P , Eisner ER (eds) Regional and

local anesthesia Veterinary Dental Techniques for the Small

Animal Practitioner , 3rd ed Saunders , Philadelphia , 2004 ;

625 – 636

Joubert K , Tutt C Anaesthesia and analgesia In: Tutt C ,

Dee-prose J , Crossley D (eds) BSAVA Manual of Canine and Feline

Dentistry , 3rd ed BSAVA , Gloucester , 2007 ; 41 – 55

Mazzafero E , Wagner AE Hypotension during anesthesia in

dogs and cats: recognition, causes, and treatment Comp

Cont Ed Pract Vet 2001 ; 23 : 728 – 737

• Stage 4 advanced periodontitis occurs where there

is greater than 50% loss of periodontal support Extraction is generally the treatment of choice

Plaque and Calculus Removal

Plaque and calculus can be removed by hand using fi ne curettes or with the help of ultrasonic scalers equipped with periodontal tips

Ultrasonic sound waves are composed of alternate compressions and rarefactions During the low - pressure rarefaction cycle, microscopic bubbles are formed Through the high - pressure compression cycle, the bubbles collapse or implode These implosions produce

Treatment of Periodontal Disease

Chapter 8

Goals of periodontal therapy include removing irritants

and debris from the tooth surfaces and periodontal

pockets, and minimizing pocket depth and attachment

loss while maintaining at least two millimeters of

attached gingiva

Periodontal therapy ranges from removing plaque

and calculus in cases of gingivitis, to mucogingival

surgery, to extracting affected teeth Periodontal therapy

decisions should be made by evaluating clinical and

radiographic examination results together with client

input concerning expectation, fi nances, and ability to

provide essential after care

Stage of disease at the time of the oral assessment

dictates the recommended therapy (table 8.1 ) Gingivitis

is confi ned to gingival soft tissue infl ammatory changes

Periodontitis is diagnosed when there is loss of tooth

support from the peridontium

• Stage 1 disease is characterized by gingival infl

am-mation without loss of periodontal support

Radio-graphs are developed and examined to give more

information about additional pathology present

Gingivitis is treated with plaque and calculus

removal, polishing, and irrigation of the crown and

the gingival sulcus Once the irritating plaque and

calculus are removed, the gingiva returns to normal

as long as home care is instituted

• Stage 2 early periodontitis is present when there is

less than 25% loss of periodontal support Stage 2

disease is treated as above, plus removal of plaque

and calculus from the exposed root surface

(subgin-gival scaling root planing) and gin(subgin-gival curettage

• Stage 3 established periodontitis exists when 25%

to 50% of the periodontal support is lost The

prog-nosis is better when there are nonpocket defects

compared to pocket defects, which readily

accumu-late oral debris after the oral assessment, treatment,

and prevention (Oral ATP) visit Efforts of plaque

and calculus removal versus extraction must be

weighed against the ability to provide daily home

care

Table 8.1. Summary of periodontal therapy

Stage Disease Description Therapy

Stage 1 Gingivitis Infl ammation without

periodontal support loss

Supragingival scaling, irrigation, and polishing Stage 2 Early

periodontitis

Infl ammation, swelling, gingival bleeding upon probing, with up to 25%

periodontal support loss

Supragingival and subgingival scaling, irrigation, and polishing Stage 3 Established

periodontitis

Infl ammation, edema, gingival bleeding upon probing, pustular discharge, moderate bone loss, between 25% and 50% periodontal support loss

Supragingival and subgingival scaling, irrigation, and polishing; extraction

of affected teeth if owner cannot provide home care

Stage 4 Advanced periodontitis

Infl ammation, edema, gingival bleeding upon probing, pustular discharge, tooth mobility, marked ( > 50%) periodontal support loss

Extraction of affected teeth

182 Feline Dentistry

2 Adjust water spray to deliver a steady drip with a small mist halo (fi g 8.2 )

3 Apply the side of the scaler lightly to the crown in

a coronal - to - apical direction The sound waves should do most of the work Effi ciency decreases with increased pressure

Figure 8.3 Proper position of ultrasonic scaler against crown surface

shock waves (cavitation) that disrupt the bacterial cell

wall and lead to bacterial cell death Additionally,

acous-tic streaming occurs when a continuous torrent of water

produces tremendous pressure within the confi ned

space of the periodontal pocket, resulting in a decreased

number of bacteria Gram - negative, motile rods in

par-ticular are sensitive to acoustic streaming because of

their thin cell walls

Operator and Patient Protection

To protect from bacterial aerosols and other effects of

ultrasonic scaling, the operator should wear a surgical

mask, ear protection, gloves, glasses, and/or a face

shield, surgical cap, and smock

The anesthetized patient should have artifi cial tears

ophthalmic preparation applied to the corneal surfaces

to protect from drying and irritation When in lateral

recumbency, the cat ’ s head should be cushioned to

protect the eye closer to the table surface from abrasion

and to raise it off the table to prevent water

contamina-tion The upper eye should be draped to protect it from

fomites and from prolonged exposure to the procedure

light (fi g 8.1 )

The mouth is rinsed with 0.12% chlorhexidine

gluco-nate or acetate before the scaling begins

Treatment of Periodontal Disease 183

Subgingival (Below the Gum Line)

Scaling

Calculus, coated with bacteria, left on the root surface

contributes to the progression of periodontal disease If

subgingival calculus removal is not performed, the teeth

have not been adequately cleaned

Subgingival root cleaning can be accomplished with

curettes or special ultrasonic, thin, periodontal tips

man-ufactured specifi cally for root surface use When there is

enough space between the marginal gingiva and root, a

fi ne curette can be inserted with the face of the blade

fl ush against the tooth When the instrument reaches the

bottom of the pocket, the working angulation of the

instrument – - usually anywhere between 45 and 90

degrees – - is established The instrument is then pushed

against the tooth and pulled coronally This process is

repeated until all subgingival calculus is removed (fi g

8.4 )

To avoid iatrogenic injury when using the ultrasonic

scaler with periodontal tips for removal of plaque and

calculus, decrease the power and increase the amount of

water irrigation

After ultrasonic tooth cleaning is completed, use air

from the air/water syringe to gently blow the gingival

margin away from the tooth, and examine the tooth

surface for missed plaque and calculus Water from the

air/water syringe is used to lavage unattached debris

from the sulcus or pocket after cleaning

Tooth Polishing

Polishing smoothes minor enamel defects and removes

some of the plaque missed during previous steps

Regardless of how careful scaling and curettage are

per-formed, minor defects (microetches) of the tooth surface

occur Polishing teeth decreases the surface area of

enamel and cementum microetches, retarding plaque

reestablishment

Tooth polishing can be accomplished by applying

polishing paste on the prophylaxis cup attached to a slow

speed handpiece Cross - contamination can be avoided

between different cats by using disposable polishing

angles and individual paste cups When polishing, light

pressure is applied to each tooth until the cup edge

fl ares Care must be taken not to hold the cup on one

spot for more than a few seconds to prevent overheating

and subsequent damage to the pulp Cementum and

dentin are softer than enamel When exposed from

gingival recession, they should be polished for a few

seconds only to avoid further wear

Figure 8.4 Thin curette (NVO Cislak)

Air polishing uses sodium bicarbonate to “ sandblast ” the tooth surface smooth in addition to or as a replace-ment for conventional polishing The small size of cat teeth generally precludes air polishing due to potential iatrogenic damage to the gingiva

Fluoride Application

Potential fl uoride advantages in veterinary dentistry include reduction in tooth sensitivity from exposed den-tinal tubules, decreased plaque accumulation, increased enamel resistance to acid demineralization, and a client - pleasing cherrylike aroma after application (FluraFom Virbac Products)

Fluoride can be applied while the cat is anesthetized, after the teeth are cleaned and polished and before the plaque barrier gel OraVet ® is applied Both the gel and foam have a pH of 3.0, which may cause gastric irritation and nausea if swallowed; it is therefore administered in the clinic while the patient is still intubated and has a barrier in the oropharynx

Fluoride is deposited in the gingival sulcus with a cotton - tipped applicator, a soft toothbrush, or a foam

184 Feline Dentistry

applicator and is allowed to remain in contact with the

tooth surface for three minutes When using fl uoride

foam, approximately one - half inch of the foam is rubbed

over the teeth After three minutes, the foam is removed

with suction or with a dry gauze sponge Irrigation is

not used after fl uoride application (fi g 8.5 )

Barrier GEL

OraVet ® (Merial) can be applied to the crown and root

to provide a barrier against plaque attachment The

Figure 8.6 a OraVet ® professional application kit b Applying OraVet ®

Treatment of Periodontal Disease 185

tion Chlorhexidine can devitalize periodontal ment cells and interfere with attachment

2 Create an access fl ap with interdental and sulcular incisions Plane the root smooth with a curette and remove excess granulation tissue

3 Add four to six drops of the patient ’ s blood, sterile water, or saline to 0.5 mL of the graft material in a dappen dish

4 Mix the liquid and granules (e.g., Consil ® ) in the dappen dish with a spatula for ten seconds to achieve the consistency of fi rm wet sand and apply it into the defect area Alternatively, carry the granules to the defect and mix with the patient ’ s blood In two

to three minutes, a chemical change occurs within the granules that initiates the process of bone regen-eration Consil Putty ® can also be applied into the defect

5 Suture the access fl ap without tension

Postoperative care includes pain control and crobial medication The cat is fed a soft diet for several days Gentle brushing can begin one week after surgery The surgical site is reexamined every two weeks until clinical healing is confi rmed The area is radiographed

fi stula

1 Make 2 – 4 mm mesial and distal incisions to the bone

at 20 - degree angles palatally from the affected tooth (fi gs 8.7 c, d)

2 Use a Molt or Freer periosteal elevator to gently raise

a full - thickness fl ap (fi gs 8.7 e, f)

3 Use a thin curette to clean accessible granulation tissue, calculus, and plaque between the root and alveolus (fi gs 8.7 g, h)

4 Carry bone - grafting particles into the cleaned defect (fi g 8.7 i)

5 Oppose the fl ap snugly against the tooth with

4 - 0 absorbable suture on an atraumatic needle (fi g 8.7 j)

Antibiotics

Bacterial load in the mouth and bacteremia can be

sig-nifi cantly decreased when the oral cavity is rinsed with

0.12% chlorhexidine gluconate after general anesthesia

is induced and before tooth cleaning or oral surgery

Antibiotics are not indicated in most patients with

periodontal disease The goal of periodontal therapy is

to remove the cause of infl ammation – - plaque, calculus,

or periodontal pockets Treating the infection with

anti-biotics but without mechanical debridement will at best

result in a temporary improvement and at worst cause

the development of resistant pathogens

In stage 3 and 4 periodontal disease, antibiotic use is

controversial but may be indicated Choosing the

appro-priate antibiotic can be challenging One in - vitro study

found either amoxicillin - clavulanic acid or cefadroxil

most effective against gram positive and negative

aerobic bacteria in cats with gingivitis For anaerobic

bacteria, amoxicillin - clavulanic acid or clindamycin

were most effective

Pulse therapy is the use of periodic (i.e., fi rst fi ve days

of every month) oral antibiotic administration to help

control the bacterial load However, this is only rarely

recommended as an adjunct in cases where periodontal

pocket disease has been treated and the client can

provide daily home care Pulse therapy is not indicated

in cases where periodontal disease exists, anesthesia is

not performed due to client or practitioner concerns, or

as a substitute for home care

Bone Grafting

Bone grafts are used to preserve or restore the alveolar

height in deep, narrow, three - walled infrabony pockets,

such as defects on the palatal side of canine teeth, that

do not extend into the nasal cavity The goals of bone

grafting are to restore normal bony architecture, rebuild

the periodontal ligament and soft tissue, and prevent

further periodontal pocket formation

Many materials have been used for cat bone grafts,

including autogenous bone, alloplasts, and synthetic

bioactive ceramic such as Bioglass ® (Consil ® , Consil

Putty Nutramax Laboratories), which develops a direct

bond to tissue and becomes osteoconductive when

implanted into an osseous defect The ceramic is

sur-rounded by and incorporated into the new bone within

weeks

General Technique

1 If chlorhexidine is used as an irrigant during surgery,

rinse it off thoroughly with lactated Ringer ’ s