The study of composition and properties of dental materials and the manner in which they interact with the environment they are placed. | Science of Dental Materials |
Science of Dental Materials deals with what? | • physical properties
• mechanical properties
• biological properties
• interaction with oral cavity (tissues) |
Why are we studying DNMATL1? | to gain knowledge to make optimal selection of materials |
What is the appearance of the materials? | in liquid, powder, and paste form |
What is the main goal in dentistry? | to maintain or improve the quality of life through replacement or alteration of tooth surfaces |
temperature variations in the oral environment | 32 degrees to 37 degrees Celsius |
temperature variations in the oral environment during intake of cold/hot drinks | 0 degrees to 70 degrees Celsius |
pH of saliva | neutral (7.0) |
pH of saliva on intake of acidic fruits or alkaline medicaments | pH 2.0-11.0 |
characteristic of a dental material that is non-toxic, non-irritating, non-allergenic | biocompatible |
characteristic of a dental material that is strong, resistant to fracture | mechanically stable and durable |
characteristic of a dental material that does not deteriorate over time | resistant to corrosion |
characteristic of a dental material that is not changes with a little change in temperature and solvent | dimensionally stable |
characteristic of a dental material that insulates against thermal/electrical change | minimal conduction |
characteristic of a dental material that looks like the oral tissue | esthetic |
characteristic of a dental material that is minimal/reasonable effort and time needed to use | easy to manipulate |
characteristic of a dental material that retains onto, and seals, tooth structures | adheres to tissue |
characteristic of a dental material that is not unpleasant to patient | tasteless and odorless |
characteristic of a dental material that is easily maintained or fixed | cleanable/repairable |
characteristic of a dental material that is affordable | cost-effective |
where are dental materials used in? | oral cavity and laboratory |
to prevent any pathology (disease), cavities, infections | Preventive Dentistry |
aims to provide resistance to the progression of caries | Preventive Dentistry |
addition of fluoride to water to reduce tooth decay | Fluoridation |
application of fluoride in paste form | Fluoride Therapy |
a pathological condition resulting from an excessive intake of fluorine (usually from drinking water) | Fluorosis |
repairs or replaces defected tooth structures | Restorative Dental Materials |
amalgam, composites, compomers, bonding agents, ceramics, liners, cement bases and polymers are what type of dental materials? | Restorative Dental Materials |
used in the process of fabricating prostheses | Auxillary Dental Materials |
hard, lustrous, dense, and good conductor of heat and electricity | metals |
structures that absorb x-rays and appear white on the radiograph | radiopaque |
combination of two or more metallic elements to give strength and resistance to corrosion | dental alloy |
precious metal (60% gold, platinum) | high noble |
25% noble material | semiprecious |
base materials (contains nickel, cobalt) ex: amalgam | nonprecious |
inorganic, non-metallic materials made by man by the heating of raw minerals at high temperature, hard and abrasive, and brittle | dental pocelains |
long-chain molecules consisting of many repeating units | polymers |
low melting points, soft and not stiff, and synthetically produced | polymerization |
hand-powered dental instruments | hand instruments |
credited with the first acceptable nomenclature and classification of hand instruments | Greene Vardiman Black |
material harder than stainless steel | carbon steel |
shiny, loses keen edge during use more quickly | stainless steel |
it is the part grasped in the operator’s hand | handle |
perfectly straight, smooth or eight sided, serrated for better gripping or control of the instrument | handle |
allows for replacement of several working ends e.g. mirrors and condensers | cone-socket handle |
connect the handle to the working end of the instrument | shank |
have on or more angles to avoid twisting of instruments | shank |
working part of the instrument | working end |
it is connected to the handle by the shank | working end |
cutting edge | blade |
working end on non-cutting instruments | nib or face |
used to view tooth structures that cannot be seen using direct vision | mouth mirror |
clear image without distortion on a mouth mirror | front surface |
magnifies the object | concave |
for diagnosing calculus and caries and exploring of pockets, restorations and furcations | dental explorer |
no. 23 explorer is also known as? | shepherd's hook |
no. 17 explorer | cowhorn or pigtail explorers |
explorer useful for the interproximal areas between teeth | no. 17explorer |
Tufts 17/23 explorer | Wilken’s Explorer |
contains both no. 17 and no. 23 on the same instrument; opposite sides of each other | Wilken’s Explorer |
used to place small objects in the mouth and retrieve small objects from the mouth | dental tweezers |
for the removal of softened, carious dentin and temporary fillings | excavators |
for cleaning out and shaping a carious cavity preparatory to filling | excavators |
digging out failed restorative material | excavators |
speed of low speed hand instruments | 3,000-6,000 rpm |
speed of medium speed hand instruments | 20,000-45,000 rpm |
speed of high speed hand instruments | 45,000-1,000,000 rpm |
speed of ultra speed hand instruments | above 1,000,000 rpm |
an economical bur used in cavity preparation and dentin removal | steel bur |
more flexible, and more resistant to chips and breakage than carbide burs | steel bur |
used for precise drilling and finishing and for grinding where material removal is not a concern | diamond burs |
used in tooth preparation in fabricating crowns | diamond burs |
produce cleaner cuts and a higher polish than carbide burs | diamond burs |
made of tungsten carbide | carbide burs |
can maintain a sharp cutting edge and be used many times without becoming dull | carbide burs |
bur that is brittle and have the tendency to fracture under pressure | carbide burs |
began the process of “standardization” | Greene Vardiman Black |
products being developed with specific properties and designed for a definite purpose | standardization |
covers alloys, composed of mainly silver, tin, and/or copper, used in the preparation of dental amalgam | ANSI/ADA STANDARD NO. 1 – ALLOY FOR DENTAL AMALGAM: 2003 (REAFFIRMED 2013) |
this standard specifies the requirements and test methods for mercury suitable for the preparation of dental amalgam | ANSI/ADA STANDARD NO. 6 – DENTAL MERCURY: 1987 (REAFFIRMED 2005) |
covers classification, requirements, and test methods for synthetic polymer and ceramic teeth that are manufactured for use in prostheses used in dentistry | ANSI/ADA STANDARD NO. 15 – ARTIFICIAL TEETH FOR DENTAL PROSTHESES: 2008 (REAFFIRMED 2013) |
covers elastomeric dental impression materials based (rubber impressions) | ANSI/ADA STANDARD NO. 19 – DENTAL ELASTOMERIC IMPRESSION MATERIALS: 2004 (REAFFIRMED 2014) |
this standard establishes the requirements for burs suitable for use with straight and angle dental handpieces | ANSI/ADA STANDARD NO. 23 (WITH ADDENDUM) – DENTAL AXCAVATING BURS: 1982 (REAFFIRMED 2015) |
covers gypsum products used for dental purposes such as making oral impressions, molds, casts, dies or model bases, and mounting models | ANSI/ADA STANDARD NO. 25 – DENTAL HYPSUM PRODUCTS: 2000 (REAFFIRMED 2010) |
this standard applies to diagnostic x-ray equipment used for intraoral radiography | ANSI/ADA STANDARD NO. 26 – DENTAL X-RAY EQUIPMENT: 1991 |
covers requirements for dental resin-based restorative materials supplied in a form suitable for mechanical mixing, hand mixing, or external energy activation | ANSI/ADA STANDARD NO. 27 – RESIN-BASED FILLING MATERIALS: 1993 |
specifies requirements for non-eugenol cements containing zinc oxide and aromatic oils suitable for temporary cementation | ANSI/ADA STANDARD NO. 30 – DENTAL ZINC OXIDE – EUGENOL AND ZINC OXIDE – NON-EUGENOL CEMENTS: 2013 |
this standard specifies requirements and test methods for dental cartridge syringes which are reusable dental syringes | ANSI/ADA STANDARD NO. 34 – DENTAL CARTRIDGE SYRINGES: 2013 |
covers ceramics suitable for use in the fabrication of metal-ceramic dental restorations | ANSI/ADA SNTANDARD NO. 38 – METAL-CRAMIC DENTAL RESTORATIVE SYSTEMS: 2000 (REAFFIRMED 2015) |
this standard is for mechanical dental amalgamators used for the mixing of alloy and mercury to make dental amalgam | ANSI/ADA STANDARD NO. 43 – ELECTRICALLY POWERED DENTAL AMALGAMATORS: 1986 (REAFFIRMED 2015) |
covers reusable and disposable impression trays used for delivering impression materials into the oral cavity for the purpose of making impression (negative copies) of teeth and oral tissues | ANSI/ADA STANDARD NO. 87 – DENTAL IMPRESSION TRAYS: 1995 (REAFFIRMED 2014) |
are based on the laws of physics that describe mass, energy, force, light, heat, electricity, and other physical phenomena | physical properties |
is a characteristic of a matter that may be observes and measured without changing the chemical identity of a sample | physical properties |
the amount of mass of a material in a given volume | density |
important in retention of the upper denture | density |
important in weight of complete or partial denture | density |
the ability of a material to flow | viscosity |
the resistance of a material to indentation | hardness |
calculated based on the size of the indentation, the load on the tip, and the shape of the tip | hardness |
the harder the materials, the more? | abrasion resistance |
susceptible to being dissolved | solubility |
adsorption plus absorption | sorption |
natural process where molecules of a gas or liquid adhere to the surface of a solid | adsorption |
passage of a substance into the interior of another by solution of penetration | absorption |
the force of attraction between the molecules/atoms of two different surfaces as they are brought into contact | adhesion |
force of attraction between molecules/atoms within one material (not on the surface) | cohesion |
measure of the affinity of a liquid for a solid as indicated by spreading of a drop | wettability |
a measure of how much it expands per unit length if heated one degree higher | Coefficient of Thermal Expansion |
the change in length per unit length of the material for a 1 degree Celsius change in temperature | Coefficient of Thermal Expansion |
the expansion or contraction of a material due to temperature changes | thermal dimensional change |
the rate of heat flow through a material | Thermal Conductivity |
a measure of liquid’s tendency to evaporate | Vapor Pressure |
generation of electrical currents in mouth | Galvanism |
results from presence of dissimilar metals in mouth | galvanism |
dissolution of materials in mouth | corrosion |
surface reaction of materials to components in saliva or food | tarnish |
the ability of a material to conduct the electrical current | Electrical Conductivity |
it is important to consider during electrosurgery or electric pulp testing | Electrical Conductivity |
a color space that specifies colors based on three properties of color: hue, value (lightness), and chroma (color purity) | Munsell Color System |
three properties of color | hue, value (lightness), and chroma (color purity) |
color purity | chroma |
value of color pertains to? | lightness of color |
a property of a material that allows the passage of light in such a manner that little distortion takes place so that objects can be clearly seen through them | transparency |
a property of the material which allows the passage of some light and scatters or reflects the rest. in such manner, the object cannot be seen clearly through them | translucency |
a property of the material that prevents the passage of light. opaque material absorbs all of the light | opacity |
color that means materials absorb all light colors | black |
color that means materials reflect all light colors | white |
color that means materials absorb all light colors but reflect its color | blue |
reflections on a smooth surface give a glossy appearance to the surface | specular reflection |
It is the change of the direction of a beam of light on entering second medium | refraction |
refers to the physical properties of a material when it is deformed by elastic or inelastic behavior when mechanical forces are used | mechanical properties |
load applied to an object | force |
force that pulls an object apart | tensile |
force that squeeze an object together | compression |
force that slides the top of the object over the bottom | shear |
Intraoral Biting Forces - greatest in the molar area | 580Newtons (132 lbs) |
Intraoral Biting Forces - premolar | 310Newtons (70.5 lbs) |
Intraoral Biting Forces - partial and complete dentures | 111Newtons (25 lbs) |
the deformation or change in dimension an object under stress experiences | strain |
completely reversible. disappears when force is removed | elastic strain |
permanent deformation of the material that never recovers after force is removed | plastic strain |
amount of deformation that material can withstand | percent of elongation |
amount of deformation before rupture when material is under compressive stress | percent of compression |
energy required to deform a material permanently | resilience |
energy necessary to fracture material | toughness |
used for materials in which the strain is dependent on the time the load is maintained | strain-time curves |
it can be time dependent and recoverable or time dependent and not recoverable | strain-time curves |
those that occur at high rates of loading, such as from an impact | dynamic properties |
every force you apply to an object or material | stress |
type of stress that forces towards to object | compression |
type of stress that forces are going opposite ways | tension |
twisting type of stress | torsion |
sliding forces type of stress | shear |
when force is removed, the material will come back to its original state | elastic phase |
when the force is removed, the material will not come back to its original state | plastic phase |
point where elastic phase becomes plastic phase | elastic limit |
when the material breaks | ultimate strength |
capacity of the material to absorb energy and does not deform | resilience |
the power or ability to return to the original form, position, etc. after being bent, compressed, or stretched; elasticity | resilience |
small changes in the shape of material with constant pressure | creep |
small changes in the shape the object but the force decreases overtime | stress relaxation |
capable of being bent, usually without breaking; easily bent | flexibility |
the state of being capable of being shaped, as by hammering or pressing | malleability |
ability of material to withstand permanent deformation under a tensile load without rupture | ductability |
relative inability of material to deform plastically before it fractures | brittleness |
structure subjected to repeated or cyclic stresses can produce abrupt failure of the structure | fatigue |