wk 1 - intro to radiology and physics

who uses dental radiographs

• oral surgeons

• orthodontists

• general

• periodontists

• endodontists

• TMJ

• Legal

fistula

infection in the gum

purpose of dental radiographs

• pt ed

• diagnoses

• localize lesions and foreign objects

• provide info during tx

• aid in concerns/thoughts

• evaluation of periodontal bone

• identify pathology, lesions, anomalies, etc

• measure growth

every child should get an orthodontic evaluation by

8 yo to take sure everything is correct in the mouth

bite wings show

both arches

full mouth series shows

every tooth in the mouth and should ALWAYS start in anterior when exposing

panoramic shows

mouth as a whole, less detailed

check up series consists of

2 top, 1 bottom,and bite wings

in a full mouth series, what tooth should ALWAYS be centered

second molar

a diagonostic radiograph shows

apices and a bit above

are DH in NYS allowed to diagnose

NO

Wilhelm Roentgen

discovered xrays, 1895, germany

Otto Walkoff

first dental radiograph, Germany

William Rollins

• possible 1st US dental radiograph

• focused on pt and operator safety and dangers of radiation

Edmund Kells

• possible 1st US dental radiograph

• discovered time and temp of developing

Kurks tube

tube with light and shadow

Coolidge tube

controlled ionization using heat filaments

Dental xrays are dangerous because

they are ionizing which can change cell structure

matter

anything that occupies space

energy

ability to over come resistance and do work

atom

made of proton, neutron, and electrons

molecule

group of atoms that retain properties

how many elements are there

118

smallest particle of an element is an

atom

atoms are usually _____ charged

neutrally

nucleus of an atom is made of

protons and neutrons

electrons

orbit nucleus and negatively charged

max # of shells an atom can have

7 shells, K - Q

K shell

• closest to nucleus

• strongest binding energy

binding energy

energy needed to remove the electron from shell

K shell max # of electrons

2

atomic number is

number of atoms

ONLY atom that is stable without neutrons

Hydrogen

ionization

production of ions or production of changing an atom into an ion

positively charged atom is a result of

a loss of an electron

negatively charged atom is a result of

a gain of an electron

ion pairs form when

electrons are removed from an atom during ionization

electromagnetic radiation

wavelike energy movement through space and matter

electromagnetic spectrum

radiations are arranged in an orderly manner according to their energies

properties of electromagnetic spectrum

• travel at speed of light in a vacuum

• have no electrical charge

• have no mass

• pass thru space as particles and in a wavelike motion

• give off electrical field and magnetic field perpendicular to electric field

• have energies that are measurable and different

  • distance - crest to crest (wavelength)

  • frequency - #of crests per second

x-rays on electromagnetic spectrum

• short wavelength

• high energy

• high frequency

wavelength is measured

Angstroms (A)

dental radiographs are _____ Angstroms

.1-5A

frequency

number of crests passing a given point per second

frequency measured in

Hertz (Hz)

low frequency

• long waves

• low energy (Grenz rays)

high frequency

• short wavelength

• high energy (penetrating power)

background radiation

• all sources combined

• cosmic - sun

• terrestrial radiation - in ground

• naturally occurring - unstable atoms that were ingested or inhaled

man made radiation exposure

• 48% of exposure and 2% consumer products

• dental - xrays

• medical - CT, xrays

• consumer products - cigarettes, tv, smoke detectors