BIOCOMPATILITY of DENTAL MATERIALS
Biomaterial may be defined as a non living designed to interact with biological system
Biocompatibility is the ability to elicit an appropri-ate biological response in a given application in the body
Biological response will changes in the host, the application material, material its self
A materials may be said to be biocompatible when it has the quality of being non destructive in the biological environtment
A single material may not be acceptable in all application
Possible interaction between material and environment:
- postoperative sensitivity - toxicity - hypersensitivity/allergic - corrosion In the development of any biomaterial
must be consider: - strength - esthetic - functional &
biocompatibility
Measuring Biocompatibility
Is not simple About the interactions between dental
material oral tissue and technologies for testing improve
Must be extensively screened for biocompatibility before are used in human
- in vitro (primary test, initials test) - animal (in vivo, secondary test)
- usage test
Advantages and Disadvantages
In vitro test Advantages: - quick to perform - lest expensive - can be standardized - large scale screening - good experiment control - good excellence for
mechanism of interaction Disadvantages : relevance to in vivo is questionable
In vivo test : Advantages: - allows complex systemic interaction - response more comprehensive - more relevant Disadvantages: - relevance to use of materials
questionable - time consuming - legal / ethical concerns - difficult to control - difficult to interpret and quantity
Usage test Advantages : - relevance to use of material is
assured Disadvantages: - very expensive - very time consuming - major legal/ethical issue - can be difficult to control - difficult to interpret and quantity
ANSI / ADA Specification 41 3 category of test (1982): - initial test - secondary test - usage test : a. placement of the materials in
intended b. first in larger animal / primates c. Food & drug Administration approval ISO 10993 - ISO 10993 ( 1992) - ISO 7405 (1997) revised
Standard that regulate the measurement of biocompatible
The reason
The vast advance of cellular & molecular biology
The variety of test available for assessing biocom-patibility of material
The lack of standardization of these test
Recommended Levels of Biologic Testing (ANSI /ADA)
Initials Tests - Short term systemic toxicity test: Oral route - Acute systemic toxicity test: Intravenous route - Inhalation toxicity test - Hemolysis test - Ames mutagenicity test - Styles cell transformation test - Dominant lethal test - In vitro cytotoxicity test (Cr release) - Cytotoxicity test (Millipore filter) - Tissue culture agar overlay test
Secondary Tests - Subcutaneous implant test - Bone Implant - Sensitization test - Oral mucous membrane irritation
test
Usage Test - Oral mucous membrane irritation
test - Pulp and dentin test - Pulp capping and pulpotomy test - Endodontic usage test - Bone implant usage test
Short Term Systemic Toxicity Test (Oral route)
Penetapan toksisitas material jangka pendek Hewan coban: 40 tikus, 8 minggu, 130-150 mg
BB Kandang: 33 x 28 x 16 cm, 5 tikus, diet
standart Material dibuat serbuk
larutan/suspensi atau dicampur dlm makanan (dosis 1 g/kg BB)
Cara pemberian materi: dgn alat intragastric needle, atau stomach tube (kontrol dgn aquadest)
Observasi: 7 hari, amati perub. dan timbang BB/hr
Euthanasia dgn eter (inhalasi) kmd necropsy Interprestasi: mati, toksik klinik, BB, jaringan
Acute Systemic Toxicity Test(Intravenous route)
Hewan coba, perkandangan spt STSTT oral Materi: dilarutan dlm 0,9% NaCl, Cara pemberian: suntikan i.v pada vena
cauda dgn dosis 5 ml/100 g BB, bila tak larut extract 4 g dipotong kecil-kecil, masukkan dlm 20 ml saline normal, di autoclve 121o C 1 jam, semua extrac disuntikkan
Pengamatan: observasi selama 7 hari Euthanasia dgn eter dan necropsy Interprestasi: mati, toksik klinik, BB, jaringan
Hemolysis Test
Evaluasi aktivitas hemolitik pada bahan yang kontak lama
Rational: - hemolitik dasar: pelepasan Hb - hemolitik komponen solubel dan permukaan fisik: total hemoltik Material: centrifuge, waterbath, test tube,
spectro-fotometer, tabung pipa darah Prosedur: - Darah kelinci oksalat : 0,2 ml di hemilisis dalam 10 ml akuades (dibaca pada λ : 545 nm : 0,8 ± 0,5 o.d)
- Bahan 5 gr (dipotong 0,5 mm) dlm 10 ml saline normal dlm waterbath 37oC selam 30 menit
- Kontrol + : 0,2 ml lar. darah dlm 10 ml akuades - Kontrol - : 0,2 ml lar. darah dlm 10 ml saline
normal (o.d < 0,3) (o.d sampel – o.d kontrol neg) % hemolisis = ------------------------------------
x100% (o.d kontrol pos - o.d kontrol neg) Uji antar mean statistik Respon hemolisis > respon kultur jaringan
Subcutaneous implant test
Hewan coba: tikus Rational: Prosedur: - implan 3 mm (Ǿ) x 10 mm (p) - insisi 0,5 cm kemudian diseksi tumpul + I
cm - evaluasi pada 48 jam, 2 minggu dan 12
minggu. (inflamasi, nekrosis, pertinent changes) - Kriteria : tidak ada reaksi inflamasi / reaksi ringan, moderat, parah
Ketentuan implan
- Bahan diterima : a. tdk ada/reaksi ringan pd minggu 2 dan
12 b. reaksi moderat pd minggu ke hilang
pada 12 - Bahan ditolak: a. ada reaksi ringan pd minggu ke 2
meningkat ke moderat/ parah pada ke 12 b. Reaksi moderat pada minggu 2 dan 12 c. Reaksi parah pada minggu 2 dan 12
Biocompatibility of Dental Materials (2)
Reaction of pulp
Microleakage: …………………….. (nanoleakage)
- contracting during polymerization - wear - thermal cycling saliva invasion microorganism inflammation/infection
Dental bonding - bonding to dentin has proven more
difficult a. organic and inorganic b. wettability >> EDTA, Na-
hypochloride c. lower mineral content (in dentin) - occurred hybrid layer of resin & collagen - removal of smear layer caused: a. its juxtaposes resin & dentin
without barrier b. make any microleakage more
significant c. acid are potential source irritation
Dentin bonding agent
cytotoxicity: HEMA 100 X less toxic than bis-GMA
- combination HEMA and other resin, act synergis
tically - some resin component enhance the
growth of oral bacteria - the ability of resin based material to
increase plaque formation
Resin base materials release (Resin composite: organic & inorganic
phase) - freshly set chemically & light cured resin
cause moderate cytotoxicity, and reduced 24-72
hours (with dentin barrier) - be mediated by resin component release - light cure < chemically cure (depend on :
efficiency of the light and type of resin) - reaction diminished 5 – 8 weeks and an increase in reparative dentin
CURRENT BIOCOMPATIBILITY ISSUES IN DENTISTRY
Latex
- 6-7% surgical personnel may be allergic to latex
- 42% dental personnel: dermatoses of hands & finger
- hypersensitivity reaction was cause by true
latex, accelerator or antioxidant (in processing) Nickel
- the most allergenic metal (10-20%)
- is a known cross-reactivity between Ni and Pd
patient who are allergic Ni will be allergic to Pd
- Ni sulfide is a respiratory carcinogen
- Ni+ is a mutagenic in human
Beryllium - Beo & Be + is a carcinogenic - acidic environment enhance Be
release from Ni-Cr - Be - containing particle (dust) that
are inhaled cause berylliosis
Mercury - access to the body via the skin or
vapor - toxic effect is 3 µg/kg
Estrogenicity - bisphenol A (BPA & BPAD) is a estrogenic effect - evidence comes from estrogen receptor-
BPA binding Residual Resin - to be allergy because exposure to
unpolymeri- zed materials. - have significant toxic effect (invitro test) - the use of glove is not effective in
preventing to monomer resins - resin component have been to transverse
the dentin
Effect of Metal Ions on Tissues
Cytotoxicity / allergenic / carcinogenic - the rate metal ion release depend on: a. form of metal / alloys b. great of chemical reactivity - mechanical preparation - residual stress - cleaner surface c. composition alloy & specific
environment
Amalgam and casting alloys
Amalgam: - by corrosion product release (γ2) - marginal microleakage - mercury residu
Glass ionomer - freshly prepared is mildly cytotoxixity - fluoride release (cytotoxicity in
vitro) - increased dentin permeability after
etching
Liners, Varnishes & non resin cement Liners (CaOH) : - pH alkaline (12) extreem cytotoxicity - containing resin mild to moderate in
culture varnish containing copal & polystyrene - resin component dissolve - formation pinpoint holes Non resin ZnPO4 : low pH and leaching of Zn Zn OE : suppresses nerve transmission and
anti inflammatory Bleach agent- peroxide can rapidly traverse the dentin- chemically burn the gingiva
Reaction of Oral Soft Tissue to Restorative material
- product of bacterial plaque & accumulate - buffering & protein-bonding to mitigate
cytotoxic - direct contact resin composite with
fibroblast caused leach out un polymerized
component - roughness surface - hypersensitivity of the acrylic & diacrylic monomers
Reaction bone & soft tissue to implant materials
(osseointegration / biointegration)
Van der Waals force Mechanical entrapmentCompressive forceChemically bond
Mechanical entrapmentPhysiologically reaction(Calcification process)
Bioactive - Ceramic
TISSUE BIOGLASS
Cation & silica Dissolution network
Na – O - Si
Si – O – Si
H
OHH – O – Si - Silanol formation
Si – O – Si O Si – O – Si O
Silica gel forms bycondensation of silanols(silane chain)
Ca & PO4Ca & PO4
CO3
OH-
F-
Calcium-phosphate-rich mineral forms
Ca-P mineral crystallizes into a hydroxy, carbonate, Fluorapatite layer
Ca10(PO4)6(OH)F
Attachment between metal and tissue
Diffusion oxygen and metals ion into tissue
Diffusion hydrogen and oxygen into tissue to form hydroxides
Diffusion of mineral or atoms from electrolyte in to the oxides
Dissolution of oxide metal ion (corrosion)
Adsorption at biomolecular Desorption for replacement of
biomolecular Fragmentation of modification of
biomolecular
Top Related