5. Biocompatibility of Dental Materials Flashcards
Biocompatibility
• Definition:
The ability of a material to generate a proper ____ response in a given application in the body.
Being harmonious with life, not having a toxic effect or injuring biologic function.
biologic
Elements of Biocompatibility – No local \_\_\_\_ effects – No toxic components with \_\_\_\_ effects – No \_\_\_\_ components – No \_\_\_\_ potential
local
remote
allergenic
carcinogenic
Systemic Effects
Produced by the substance release by the material when:
• Ingested and absorption in the ____ track
• Inhaled ____
• Released at the ____ apex
• Absorption thru the oral mucosa
Systemic biological responses to a dental material depends on: • the \_\_\_\_ and concentration of the exposure • the \_\_\_\_ rate of the substance • the site of the \_\_\_\_
gastrointestinal vapor tooth duration excretion exposure
Allergic Reactions
• Type I: ____
• Type II: ____ hypersensitivity reaction
• Type III: ____hypersensitivity reaction
• Type IV: ____ hypersensitivity reaction
anaphylaxis
cytotoxic
immune complex
delayed or cell-mediated
Carcinogenic Effect
• Carcinogenicity: Ability to cause ____. (no dental material shown to be ____)
• Mutagenicity: Ability to cause alterations on the ____ base-pair sequences.
MUTAGENIC ≠ ____
cancer
carcinogenic
DNA
carcinogenic
Regulating Bodies
• ____–Food and Drug Administration
• ____–American National Standards Institute
• ____–American Dental Association
• ____–International Organization for Standardization
FDA
ANSI
ADA
ISO
Role of ADA, FDA • \_\_\_\_ for standards/ Revision of standards • \_\_\_\_ program • Applications for material \_\_\_\_ • \_\_\_\_
guidelines
certification
compliance
complaints
ADA Activity on Biocompatibility
• 1972
– Recommended ____ Practices for Biological Evaluation of Dental Materials
• 1979- Revised Edition
• New Document
– ____ Evaluation of Biocompatibility of Medical Devices used in Dentistry- Test Methods (International Standard)
standard
preclinical
Evaluation of biocompatibility of medical devices used in dentistry (11/25/2008)
- ISO7405:2008 specifies ____ methods for the evaluation of biological effects of medical devices used in dentistry. It includes testing of ____ agents that are an integral part of the device under test.
- ISO7405:2008 does ____ cover testing of materials and devices that do not come into direct or indirect contact with the patient’s body.
- ISO7405:2018 (updated October)
test
pharmacological
not
Evaluation sites of Biocompatibility
- Localized Toxicity-____ and surrounding soft tissue
- Systemic Responses-From ____ toxic materials in circulation
- Allergenicity -Potential ____ agents
- Carcinogenicity-____ potential
pulp
diffusible
sensitizing
carcinogenic
Tests for Evaluating Biocompatibility • Sequential testing to reduce number of \_\_\_\_ that will need to be tested clinically • Three levels of evaluation – \_\_\_\_ Tests – \_\_\_\_ Tests – \_\_\_\_ Tests – \_\_\_\_ Usage Test
compounds primary secondary tertiary preclinical
Testing Strategy
• Primary Tests: ____ and in-vivo test, but not necessarily related to the use of the ____.
• Secondary Tests: are more advanced ____ test that may be ____ related to the use of the material.
• Usage Tests: are either clinical trials in ____ or a close model of the use of a ____ in higher animals.
in-vitro materials biological partly human material
Primary Tests • Cytotoxicity – \_\_\_\_ culture studies – Membrane studies – \_\_\_\_ membrane lysis (hemolysis)
• Genotoxicity
– Evaluation of ____ changes on cells, bacteria, yeast or fungi
– ____ mutations, other genetic changes
– Mutagenesis and ____ at the cellular level
tissue
red blood cell
genetic
gene
carcinogenesis
Cell Culture techniques
• Zone of inhibition of cell growth
• ____ days
1-3
Primary Tests- Cytotoxicity
• ____ overlay Method
• Consequences of short term ____ of chemicals from the surface of materials
• Release of ____ by dead cells
agar
leachability
neutral red
Primary Tests
• Cytotoxicity through
____ disk
dentin
Secondary Tests
• Systemic toxicity
– LD50 after ____ day administration: the amount of the substance required to kill 50% of the test population. A lower LD50 indicates increased ____
• Inhalation toxicity
– Rats, rabbits, guinea pigs in ____ chamber – ____ of toxicity can be determined
14
toxicity
inhalation
levels
Secondary Tests
• Inflammatory or \_\_\_\_ potential - dermal irritation, \_\_\_\_ and sensitivity tests • Skin irritation – with no \_\_\_\_ activity • Sensitization – with \_\_\_\_ activity • guinea pigs
immunologic
implantation
antibody
antibody
Secondary Tests • \_\_\_\_ Tests • Short and long term, for \_\_\_\_ inflammation, or tumor formation - Short term tests in \_\_\_\_ tissue - Long term tests in \_\_\_\_ or bone
implantation
chronic
subcutaneous
muscle
Tertiary Tests Preclinical Usage Tests
• Placement of the materials in their intended contexts
– Larger ____ and then humans
• ____ and dentin usage tests
– Subhuman ____, dogs, miniature pigs
– Positive and ____ controls – Histology after ____, 28, 70 days
animals
primates
negative
7
Preclinical Usage Tests
Pulp capping/ pulpotomy tests
- CaOH is ____ control
– Test period ____ days and 70 days
Endodontic usage tests
– ____ control
– Test period - ____ days/13 wks
negative
7
ZOE
28
Mucosal and Gingival Usage Tests
- Reactions to ____ cavity preparations and restorations
- Histological response after ____ days and 30 days for slight, moderate or severe responses
- Eliminate inflammation due to ____ and restorative procedures before evaluations
subgingival
7
prophylaxis
Dental Implants
• Successful implantation- criteria
– no ____
– no radiographic evidence of ____ radiolucency
– minimal ____ bone loss and absence of peri-implant ____ complications.
mobility
peri-implant
vertical
soft tissue
FDA Approval
• Primary and secondary tests
– Product will not be harmful to ____
• For dental products manufacturer has ____ years to prove efficacy
• ____ term data required for drugs and implant materials - for FDA
humans
7
long
Screening(1o,2o) vs. Usage Tests
• ____ correlation between screening and usage tests
• Modulating factors
– ____ barrier between material and pulp
– ____ effect of cell culture
– ____ occurring in usage tests
– Accumulation of ____ plaque around restorations
poor dentin buffering microleakage bacterial
Adverse Effects of Dental Materials • \_\_\_\_ • Inflammation • \_\_\_\_ • Mutagenicity
toxicity
allergy
Allergic Responses to Dental Materials
• Primary irritant dermatitis-____ dependent
• Allergic contact dermatitis - non ____ dependent
– most common ____ disease
– Interval between exposure and clinical manifestation - ____-48 hrs
– Effect occurs at site of ____
dose dose occupational 12 contact
Allergic Responses to Dental Materials
• Allergic contact dermatitis - non \_\_\_\_ dependent (contd) – A prior \_\_\_\_ exposure is necessary – Orthodontists and pedodontists • 50% of \_\_\_\_, 1% patients – \_\_\_\_ of bonding agents, acrylic resin
dose
sensitizing
personnel
monomers
Allergic Contact Stomatitis
Common Allergens in dental Materials
• ____, cobalt, ____, eugenol, MMA monomer, bonding resin, ____, components of composite resin, gold
• Tests - ____ test
chromium
mercury
formaldehyde
patch
Latex allergy • True latex allergy • Allergy to reactants in \_\_\_\_ • 6-7 % of surgical personnel • Localized \_\_\_\_ & swelling • Wheezing and \_\_\_\_ • Repeated and prolonged exposure increases \_\_\_\_ of response • Use vinyl or \_\_\_\_ gloves
processing rashes anaphylaxis degree nitrile
Nickel Allergy • 10% \_\_\_\_ population • 1% males – less exposure to \_\_\_\_ plated jewelry • 30% of patients with \_\_\_\_ allergy react to nickel containing dental restorations
female
gold
previous
Beryllium Allergy and Toxicity
• Caused by inhaling ____ dust
• Grind beryllium containing alloys with ____ and adequate ventilation
beryllium
masks
The Mercury Controversy
• Inorganic mercury & methyl mercury
• Mercury in the ____ chain
• Ingested mercury- poorly ____
• Inhaled mercury is ____
• No direct relationship between ____ fillings and blood mercury levels
• Recognized symptoms of mercury poisoning
– ____, fatigue, anorexia, weight loss, ____, irritability, shyness, dizziness, and ____ of the extremities
food absorbed retained amalgam weakness insomnia tremors
Dental Iatrogenesis
Creation of problems/complications from dental treatment
• ____ Preparation
• Remaining ____ thickness • ____ use of materials
cavity
dentin
wrong
Dentin Structure Variation with depth & Age
• Variation of size & density of tubules with region
• Older patients
– deposition of reparative ____
– Less ____ tissue
– Less ability to recover
from ____
– Avoid ____ irritations due to dental Tx
dentin
pulpal
injury
pulpal
Microleakage
• Ingress of bacterial and toxic products towards ____
pulp
When is a material biocompatible?
When the material has the ability to perform with an appropriate host ____ in a specific application, and not producing ____ effects.
response
adverse
