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CDHO Advisory: Parkinson’s Disease









Use of the dental hygiene interventions of scaling of teeth and root planing including curetting surrounding tissue, orthodontic and restorative practices, and other invasive interventions for persons1 with Parkinson’s disease.


Cite as College of Dental Hygienists of Ontario, CDHO Advisory Parkinson’s Disease, 2023-03-13


Scaling of teeth and root planing including curetting surrounding tissue, orthodontic and restorative practices, and other invasive interventions (“the Procedures”).



Parkinson’s disease


Advanced practice nurses
Dental assistants
Dental hygienists
Health professional students
Public health departments
Regulatory bodies


To guide dental hygienists at the point of care relative to the use of the Procedures for persons who have Parkinson’s disease, chiefly as follows.

  1. Understanding the medical condition.
  2. Sourcing medications information.
  3. Taking the medical and medications history.
  4. Identifying and contacting the most appropriate healthcare provider(s) for medical advice.
  5. Understanding and taking appropriate precautions prior to and during the Procedures proposed.
  6. Deciding when and when not to proceed with the Procedures proposed.
  7. Dealing with adverse events arising during the Procedures.
  8. Keeping records.
  9. Advising the patient/client.


Child (2 to 12 years)
Adolescent (13 to 18 years)
Adult (19 to 44 years)
Middle Age (45 to 64 years)
Aged (65 to 79 years)
Aged 80 and over
Parents, guardians, and family caregivers of children, young persons and adults with Parkinson’s disease.


For persons who have Parkinson’s disease: to maximize health benefits and minimize adverse effects by promoting the performance of the Procedures at the right time with the appropriate precautions, and by discouraging the performance of the Procedures at the wrong time or in the absence of appropriate precautions.



Terminology used in this Advisory

Resources consulted

  1. Parkinson’s disease, paralysis agitans, shaking palsy 
    1. is a disorder of the brain that
      1. leads to 
        1. tremors
        2. difficulties with walking, movement, and coordination
      2. is a motor system disorder affecting chiefly but not exclusively older persons
    2. is a chronic, progressive disorder of gradual onset
    3. results from deficiency in dopamine.
  2. Parkinsonism, any condition with movement changes similar to those of Parkinson’s disease that is caused by other disorders, such as
    1. secondary parkinsonism
    2. side effects of certain medications.
  3. Primary Parkinson’s disease, a condition for which the cause of the changes in the brain is unknown.
  4. Secondary parkinsonism, where the disease is believed to be associated with changes in the brain caused by
    1. infection
    2. certain medications
    3. some chemicals.
  5. Young-onset Parkinson’s disease, where the diagnosis is made for a person in the age range 21 to 40 years.

Other terminology used in the Advisory

  1. Dopamine, a chemical messenger, which
    1. supports brain processes that control
      1. movement
      2. emotional response
      3. ability to experience pleasure and pain
    2. is deficient in Parkinson’s disease because of the death of certain types of brain cells.
  2. Excessive salivation and drooling, caused by inefficient and infrequent swallowing, and not because of excessive production of saliva.
  3. Postural hypotension and hypotension following meals
    1. are common conditions among older adults
    2. cause dizziness, syncope, and falls in older people
    3. may result in significant morbidity, decreased function, and mortality
    4. are caused by dysregulation of blood pressure in older adults with conditions such as
      1. Parkinson’s disease
      2. diabetes
      3. hypertension
  4. Tremor, an involuntary shaking movement, that
    1. is often most noticeable in the hands and arms
    2. may affect almost any
      1. body part including the head
      2. body function including the voice
    3. is of three main types
      1. resting tremors, which 
        1. are present when the muscles are at rest
        2. disappear or diminish when the muscles involved are moved
      2. intention tremors, which 
        1. occur at the end of an intended movement
        2. are absent while the affected body part is at rest
      3. action tremors, which occur when the arm or leg is held against gravity in one position for a period of time. 

Overview of Parkinson’s disease

Resources consulted

Parkinson’s disease 

  1. results from degeneration or death of neurons in a part of the brain that controls movement
  2. may also involve parts of the brain besides those concerned with motor control, leading to non-motor symptoms
  3. arises from loss of cells that produce dopamine in the brain, which 
    1. progressively impairs the brain’s ability to send messages
    2. results in loss of muscle motor function
  4. affects chiefly but not exclusively older persons
  5. in occurrence 
    1. is the second most common neurodegenerative disorder, after Alzheimer’s disease
    2. is predicted to become more common as the population ages 
    3. affects one in every 100 Canadian adults, for a total of more than 100,000 persons
    4. arises below the age of
      1. 40 years in 10 percent of the affected population
      2. 50 years in 20 percent of the affected population
      3. 65 years in 50 percent of the affected population
    5. is more likely in men than women
    6. affects children, though rarely
    7. may run in families, in which it may arise in young persons 
    8. is found throughout the world, though with rates which vary from country to country
  6. is chiefly of unknown cause, though 
    1. it has appeared in several generations of some families, indicating that certain forms of the disease may be hereditary or genetic
    2. mutations in more than 20 genes have so far been linked with it
    3. the role, if any, of environmental or other external factors is unclear 
  7. is characterized by signs and symptoms that 
    1. commonly first manifest as
      1. unilateral trembling of a hand or limb, especially when the body is at rest
      2. the sensation that one leg or foot is stiff and dragging
    2. vary according to the loss of functionality
      1. which differs among persons
      2. which worsens over time in all persons
    3. involve either or both sides of the body
    4. include motor symptoms, producing effects on
      1. movements, including
        1. difficulty starting or continuing movement, such as starting to walk or getting out of a chair
        2. loss of small or fine hand movements causing
          1. writing to become small and difficult to read
          2. eating to become difficult
        3. slowed movements
        4. tremors
        5. inability to move
        6. gradual loss of spontaneous activity
        7. difficulty chewing and swallowing
        8. impaired balance and coordination, leading to
          1. problems with walking
          2. falls
        9. reduced voice volume, difficulty with speech 
        10. shuffling gait, decreased arm swing and slight foot drag
        11. excessive salivation, drooling 
        12. impairment of facial signs
          1. lack of facial expression
          2. difficulty communicating by facial expressions
        13. loss or impairment of blinking and other automatic movements
      2. muscles, including
        1. stooped posture
        2. muscle rigidity, especially causing stiffness of limbs; may also affect the jaw, tongue, eyelids, and forehead
        3. muscle aches and pains
    5. may be accompanied by non-motor symptoms, which variously include
      1. changes in personality and mood, especially 
        1. depression (CDHO Advisory)
        2. anxiety (CDHO Advisory)
      2. changes in thinking, cognition; confusion 
      3. dementia  (CDHO Advisory)
      4. memory loss
      5. hallucinations
      6. sleep disturbance
      7. fatigue 
      8. postural hypotension
      9. constipation 
      10. disorders of bladder function
      11. problems with sweating; increase in dandruff or oily skin
      12. sexual difficulties
  8. induces disability that 
    1. varies considerably from person to person
    2. includes difficulty walking, talking and completing tasks to the extent of interfering with daily living 
    3. does not prevent most persons from remaining active and leading fulfilling lives when they are supported by appropriate treatment, including oral healthcare
    4. presents young-onset patients with an especially wide range of challenges, even though the rate of progression may be relatively slow, such as 
      1. loss of employment
      2. managing finances
      3. caring for young families
      4. social isolation 
      5. decades of living with the disease, risking severe treatment-related motor complications, such as involuntary movements
      6. maintaining quality of life
  9. is investigated through symptoms and signs because it lacks a definitive diagnostic test; with most reliance on the
    1. pattern of symptoms
    2. clinical signs, and their progression, chiefly
      1. Parkinson’s tremors
      2. change in muscle tone, problems walking, unsteady posture
      3. difficulty starting or finishing voluntary movements
      4. jerky, stiff movements
      5. muscle atrophy
  10. is treated
    1. by controlling symptoms because no cause is known
    2. with medications, chiefly intended to increase dopamine in the brain
    3. by deep brain stimulation in certain patients/clients who partially respond to drug therapy
    4. to improve quality of life with
      1. good general nutrition and health
      2. exercise adjusted to the activity level appropriate for changing energy levels
      3. regular rest periods and avoidance of stress
      4. physical therapy, speech therapy, and occupational therapy
      5. railings or banisters placed in commonly used areas of the home
      6. special eating utensils
      7. social support services
      8. occasionally with ablative surgery which 
        1. may be an option for patients with very severe Parkinson’s disease who no longer respond to medications
        2. provides no cure but may help some patients with some troublesome effects
  11. cannot be prevented because the cause is unknown
  12. is characterized by a prognosis that
    1. without treatment sees the disorder progressively worsen to the point of disability and possibly early death
    2. improves at least for a time with medications that relieve symptoms 
    3. highlights social considerations for which support groups are important
  13. relies heavily on support groups, such as
    1. Parkinson Canada
    2. Parkinson Foundation, US 

Multimedia and images

Comorbidity, complications and associated conditions

Comorbid conditions are those which co-exist with Parkinson’s disease but which are not believed to be caused by it. Complications and associated conditions are those that may have some link with it. Distinguishing among comorbid conditions, complications and associated conditions may be difficult in clinical practice.

Resources consulted

Comorbidities, complications and associated conditions of Parkinson’s disease include

  1. end-stage complications which may be fatal, such as 
    1. choking, caused by accumulation of food and saliva in the mouth and back of the throat, which may result in choking or drooling
    2. pneumonia, caused by aspiration of food, saliva, and bacteria originating in the mouth
  2. autonomic function disturbances, including 
    1. bladder dysfunction
    2. bowel dysfunction, including constipation
    3. dribbling of saliva
    4. dysphagia
    5. excessive sweating
    6. postural hypotension
    7. sexual dysfunction
    8. weight loss
  3. mental health problems, including
    1. alertness, behaviour or mood changes 
    2. anxiety (CDHO Advisory)  
    3. apathy
    4. confusion or disorientation
    5. delusional behaviour
    6. dementia, which often results in problems with memory or concentration similar to those experienced in Alzheimer’s disease (CDHO Advisory)  
    7. depression, sometimes severe (CDHO Advisory)  
    8. hallucinations
    9. loss of mental functions
    10. psychosis (CDHO Advisory)
  4. neurological symptoms, including
    1. dizziness, vertigo, and imbalance 
    2. pain from comorbid joint disorders 
  5. oral and upper gastrointestinal conditions, including
    1. difficulty swallowing or eating
    2. nausea and vomiting
  6. physical and mobility conditions, including
    1. falls, with the potential for injury
    2. involuntary movements
  7. sleep disturbances, including
    1. extreme sleepiness
    2. impairment or loss of ability to turn over in bed
    3. inverted sleep-wake cycle
    4. rapid eye movement sleep behaviour disorder
    5. restless legs syndrome

Oral health considerations

Resources consulted

  1. Dental hygiene for persons with Parkinson’s disease should
    1. maximize oral health and function as the disease progresses with the intention of
      1. alleviating disorders of speech and language associated with poor oral health
      2. avoiding future, extensive oral healthcare interventions that may be made more difficult by comorbidities, complications and associated conditions 
      3. combating swallowing disorders associated with poor oral health 
      4. preventing nutritional deficiency associated with poor oral health
      5. recognizing when the need arises for periodic application of fluoride varnish to promote remineralization
    2. take account of the involuntary movements associated with the disease, which may
      1. cause the person to be restless in the dental chair
      2. lead to agitation
    3. recognize the loss of self-esteem associated with changes in the face, oral health and drooling, leading to
      1. dependence on caregivers, especially family caregivers
      2. employment challenges
      3. social isolation
    4. involve family caregivers who, as the disease progresses, may
      1. assume increased responsibility for oral hygiene, and who may need instruction on
        1. infection control and use of gloves
        2. oral hygiene technique
      2. seek for their family members peripatetic oral healthcare services for home and facility-based care.
  2. Dental hygienists should take account of the mechanisms of oral pathology in Parkinson’s disease, which include
    1. reduction in hand-to-mouth mobility and the loss of dexterity in tooth-brushing, which may contribute to
      1. accumulation of dental biofilm
      2. dental caries
      3. increased gum inflammation and periodontal disease, tooth mobility and pain
    2. deterioration of fit of removable partial or complete dentures worn routinely over a prolonged period, which may cause
      1. loss of bite stability
      2. inappropriate chewing contacts when the upper and lower teeth bite against each other, which may
        1. further loosen the fit of the dentures
        2. cause breakage of natural and artificial teeth
        3. lead to ulceration and pain in the supportive gum tissue
    3. difficulty swallowing that arises from pain, which may be linked to
      1. inflamed dental pulp and gum tissues
      2. pressure on the teeth
      3. hot or cold foods
    4. difficulty chewing caused by instability of the bite when the opposing teeth close together during chewing 
    5. excessive salivation and drooling
    6. choking risk
    7. weakness of voice in Parkinson’s disease,  which 
      1. develops when the muscles that control the vocal cords are affected
      2. may be one of the early symptoms of the condition
    8. muscle rigidity affecting the jaw and tongue
    9. postural hypotension.
  3. Dental hygienists should keep in mind that uncertainty exists about the effects of Parkinson’s disease on the occurrence of decayed, missing and filled teeth because
    1. reports of and assumptions about associations involving Parkinson’s disease, dental cavities and accumulation of dental plaque are apparently contradicted by unexpected findings that the oral health of outpatients with mild symptoms of the disease was better than that of the controls
    2. in the contrary findings, for persons with poor oral health, the oral health of persons with the disease was not different from that of the controls; thus the disease may not, of itself, invariably confer protection against caries-associated factors
    3. also in the contrary findings, the frequency of tooth-brushing was higher among the persons with the disease, an observation which may support the role of oral healthcare.


Sourcing medications information

  1. Adverse effect database
  2. Specialized organizations
  3. Medications considerations
    All medications have potential side effects whether taken alone or in combination with other prescription medications, or as over-the-counter (OTC) or herbal medications.
  4. Information on herbals and supplements 
  5. Complementary and alternative medicine

Types of medications

Resources consulted


  1. Aim at symptoms; none is curative.
  2. Comprise the following classes and types
    1. Carbidopa/Levodopa (Atamet®,  Duopa®, Parcopa®, Rytary®, Sinemet®; also, Stalevo®, which additionally contains entacapone)
      1. levodopa  
        1. is converted in the brain to dopamine to address the dopamine deficiency
        2. must be increased in dosage as the disease progresses, which may be associated with alternating bouts of disabling stiffness and uncontrolled movements
      2. carbidopa, used in conjunction with levodopa to enable the use of smaller doses of levodopa.
    2. Dopamine Agonists
      Drugs which directly stimulate the areas of the brain that respond to dopamine, such as
      • bromocriptine (Cycloset®, Parlodel®)
      • pramipexole (Mirapex®)
      • ropinirole (Requip®)
    3. Anticholinergics
      Drugs which decrease the activity of acetylcholine, a neurotransmitter that controls movement; used for the initial treatment of tremor at rest; include
      • trihexyphenidyl (Artane®, Trihexane®)
      • benztropine mesylate (Cogentin®)
    4. MAO-B Inhibitors
      Drugs used in the earliest stage of Parkinson’s disease to block the brain enzyme that breaks down levodopa, and which also are approved for the later stages, include
      • rasagiline (Azilect®)
      • selegiline (Eldepryl®, Zelapar®)
    5. COMT Inhibitors
      Drugs used as the duration of effect of levodopa diminishes with the progression of Parkinson’s disease; these act by blocking the action of the brain enzyme that breaks down levodopa, and include
      • entacapone (Comtan®)
    6. Adenosine 2A Antagonists
      Drugs which block adenosine A2A receptors in the basal ganglia; they are used to reduce “off time” (changes in the ability to move as levodopa dose wanes), and include
      • istradefylline (Nourianz®)
    7. Other medications
      1. amantadine (Symmetrel®) used as a secondary medication of tremor and rigidity
      2. rivastigmine tartrate (Exelon®) used for dementia associated with Parkinson’s disease.

Side effects of medications

See the links above to the specific medications.


The dental hygienist in taking the medical  and medications history-taking should 

  1. focus on screening the patient/client prior to treatment decision relative to
    1. key symptoms
    2. medications considerations
    3. contraindications
    4. complications
    5. comorbidities
    6. associated conditions
  2. explore the need for advice from the primary or specialized care provider(s)
  3. inquire about
    1. pointers in the history of significance to Parkinson’s disease
    2. symptoms indicative of inadequate control of symptoms of Parkinson’s disease
    3. the patient/client’s understanding and acceptance of the need for oral healthcare
    4. medications considerations, including over-the-counter medications, herbals and supplements
    5. problems with previous dental/dental hygiene care
    6. problems with infections generally and specifically associated with dental/dental hygiene care
    7. the patient/client’s current state of health
    8. how the patient/client’s current symptoms relate to
      1. oral health
      2. health generally
      3. recent changes in the patient/client’s condition.


Identifying and contacting the most appropriate healthcare provider(s) from whom to obtain medical or other advice pertinent to a particular patient/client

The dental hygienist should

  1. record the name of the physician/primary care provider most closely associated with the patient/client’s healthcare, and the telephone number
  2. obtain from the patient/client or parent/guardian written, informed consent to contact the identified physician/primary healthcare provider
  3. use a consent/medical consultation form, and be prepared to securely send the form to the provider
  4. include on the form a standardized statement of the Procedures proposed, with a request for advice on proceeding or not at the particular time, and any precautions to be observed.


Infection Control

Dental hygienists are required to keep their practices current with infection control policies and procedures, especially in relation to

  1. the CDHO’s Infection Prevention and Control Guidelines (2022)
  2. relevant occupational health and safety legislative requirements
  3. relevant public health legislative requirements
  4. best practices or other protocols specific to the medical condition of the patient/client.


  1. Contraindications to initiating the Procedures include:
    1. the potential for electrical energy transmission or electromagnetic interference (EMI) from dental/dental hygiene equipment that could affect operation or safety of an implanted deep brain stimulation system. Appropriate precautions should be taken with dental/dental hygiene procedures and related equipment.
    2. psychotic signs/symptoms in the patient/client that pose a risk to the patient/client or the dental hygienist during procedures (e.g., disorganized behaviour).
    3. use of the antipsychotic drug clozapine by the patient/client, which may cause bone marrow suppression2; the procedures should not begin until the dental hygienist confirms with the patient/client’s physician that the white blood cell count is within normal limits. 
  2. With an otherwise healthy patient/client whose signs/symptoms are under control and whose treatment is proceeding normally, the dental hygienist should implement the Procedures, though these may be postponed pending medical advice, which is likely to be required if the patient/client has
    1. symptoms or signs of exacerbation of the condition.
    2. comorbidity, complication or an associated condition of Parkinson’s disease.
    3. significant involuntary muscle movements creating a safety concern for the dental hygienist and/or the patient/client.
    4. possible immunosuppression associated with use of antipsychotic medication (in particular, clozapine).
    5. pending medical clearance for clarification of equipment safety when there is a deep brain stimulation system.
    6. had deep brain stimulation system implantation within a month prior to the dental/dental hygiene visit. Elective procedures should be delayed while initial programming is being undertaken. Patients/clients will likely be taken off PD medications while neurologists fine-tune programming, and hence motor fluctuations may be poorly controlled.
    7. Parkinson disease psychosis (PDP, which can adversely affect informed consent, decision-making, and behaviour). Attainment of better control of signs/symptoms may be indicated before attempting elective dental/dental hygiene treatment.
    8. psychotic signs/symptoms that may pose risk during, or cause inability to perform, procedures, in which care medical treatment is first needed.
    9. not complied with pre-medication, when indicated and as directed by the prescribing physician.
    10. not recently or ever sought and received medical advice relative to oral healthcare procedures.
    11. recently changed significant medications, under medical advice or otherwise
    12. recently experienced changes in his/her medical condition such as medication or other side effects of treatment.
    13. deep concerns about any aspect of his or her medical condition.


Dental hygienists are required to initiate emergency protocols as required by the College of Dental Hygienists of Ontario’s Standards of Practice, and as appropriate for the condition of the patient/client.

First-aid provisions and responses as required for current certification in first aid.


Subject to Ontario Regulation 9/08 Part III.1, Records, in particular S 12.1 (1) and (2) for a patient/client with a history of Parkinson’s disease, the dental hygienist should specifically record

  1. a summary of the medical and medications history
  2. any advice received from the physician/primary care provider relative to the patient/client’s condition
  3. the decision made by the dental hygienist, with reasons
  4. compliance with the precautions required
  5. all Procedure(s) used
  6. any advice given to the patient/client.


The dental hygienist should 

  1. urge the patient/client to alert any healthcare professional who proposes any intervention or test that he or she 
    1. has a history of Parkinson’s disease
    2. is taking medications and what these are 
    3. has, as applicable, a deep brain stimulation system
  2. should discuss, as appropriate 
    1. the importance of the patient/client’s
      1. self-checking the mouth regularly for new signs or symptoms
      2. reporting to the appropriate healthcare provider any changes in the mouth
    2. the need for regular oral health examinations and preventive oral healthcare 
    3. oral self-care including information about 
      1. choice of toothpaste
      2. tooth-brushing techniques and related devices
      3. dental flossing
      4. oral rinses
      5. management of a dry mouth 
    4. the importance of an appropriate diet in the maintenance of oral health
    5. for persons at an advanced stage of symptoms or debilitation
      1. regimens for oral hygiene as a component of supportive care and palliative care
      2. the role of the family caregiver, with emphasis on maintaining an infection-free environment through hand-washing and, if appropriate, wearing gloves
      3. scheduling and duration of appointments to minimize stress and fatigue
    6. comfort level while reclining
    7. stress and anxiety related to the Procedures
    8. medication side effects such as dry mouth, and recommend treatment
    9. mouth ulcers and other conditions of the mouth relating to Parkinson’s disease, comorbidities, complications or associated conditions, medications or diet
    10. pain management.



  1. Promoting health through oral hygiene for persons who have Parkinson’s disease.
  2. Reduction of the adverse effects, such as failure to take account of and manage the involuntary movements and agitation of persons with Parkinson’s disease.
  3. Generally increasing the comfort level of persons with Parkinson’s disease in the course of dental hygiene interventions through 
    1. communication
    2. provision of advice on scheduling and duration of appointments.
  4. Reducing the risk that oral health needs are unmet.


  1. Causing choking, and exacerbating swallowing disorders associated with poor oral health. 
  2. Performing the Procedures at an inappropriate time, such as 
    1. when the patient/client is agitated
    2. in the presence of complications or implanted neural stimulation devices for which prior medical advice/clearance is required
    3. in the presence of acute oral infection without prior medical advice.
  3. Disturbing the normal dietary and medications routine of a person with Parkinson’s disease.
  4. Inappropriate management of pain or medication.






2011-06-01; 2018-02-05 (addition of Deep Brain Stimulation); 2023-03-13


College of Dental Hygienists of Ontario, regulatory body
Greyhead Associates, medical information service specialists


College of Dental Hygienists of Ontario


College of Dental Hygienists of Ontario, Practice Advisors


Dr Gordon Atherley© 2009, 2011, 2018, 2023 College of Dental Hygienists of Ontario
O StJ , MB ChB, DIH, MD, MFCM (Royal College of Physicians, UK), FFOM (Royal College of Physicians, UK), FACOM (American College of Occupational Medicine), LLD (hc), FRSA

Dr Kevin Glasgow

Lisa Taylor

Giulia Galloro

Carolle Lepage


The College of Dental Hygienists of Ontario gratefully acknowledges the Template of Guideline Attributes, on which this advisory is modelled, of The National Guideline Clearinghouse™ (NGC), sponsored by the Agency for Healthcare Research and Quality (AHRQ), U.S. Department of Health and Human Services.

Denise Lalande
Final layout and proofreading

© 2009, 2011, 2018, 2023 College of Dental Hygienists of Ontario


1 Persons includes young persons and children.
2 Clozapine is associated with a 1% to 2% incidence of agranulocytosis, and patients/clients treated with this medication should be monitored weekly with complete blood cell counts. The most recent white blood cell count should be reviewed before dental/dental hygiene treatment is started.