Metals <—–Click here for Power Point Presentation
1. Patron Saint of dentistry : St.Appolonia of Alexandria,249 AD
2. First Known dentist : Egyptian , Hesi-Re [3000 B.C]
3. First speciality : Orthodontics 
4. Order of specialities :Ortho - Oral surgery  -Periodontics  -Prosthodontics -Pedodontics-Public health  -Oral pathology -Endodontics
5. Earliest Practice of Prosthetic arts –Phoenicians Circa
6. First Dental engine was invented in 1870
7. Pulpitis was recognized by “Archigenus “ in 100 A.D
8. Chirurgia Magna –French Surgeon “GUY de Cahuliac “ in 1386- was the first to coin the term Dentator And Dentists
9. Vesalious In 1500 of Belgium –Accurately Described the teeth of Pulp and pulp chambers
10. Fallopius – Dental Follicle ,Trigeminal nerve,auditory nerve ,Glossopharyngeal ,Hard and Soft palate
11.Credit for the accurate description of Maxillary Sinus : Dr.Nathaniel Highmore of England
12. Ambrose Pare- a barber surgeon at 16 years of age –a member of College of Surgeons at age 37- Palatal Obturators and transplant techniques
13. Purman of Breslau – Known for Wax impressions
14. Philip Pfaff in 18th century introduced Plaster Of Paris for pouring up models
15. Pierre Fauchard- Father of Scientific dentistry ,Father of Orthodontics
16.Dentistry’s First Pharmacopea –Robert Bunon 1743
17.John Green wood 1789 dentures for George Washington
18. Charles Good year – 1840- Vulcanite rubber
19. E J Dunning -1844- Made plaster of Paris impressions , first shown in America
20.First Women dentist in England – widow of Dr.Povey in 1719
21.First Women dentist In US – Emeline Rupert Jones of Connecticut
22. First Women Graduate – Dr.Lucy Hobbs in 1865-She graduated From OHIO dental college
23. Introduction Of porcelain into dentistry –Duchantenu
24. John Baker – MD surgeon Dentist –earliest qualified Dentist to practice in Boston and in America -1763 A.D
25. 1769 A.D – Title Of Doctor Began to be used
26. 1788 A.D – Improvement and development of Porcelain dentures by de Chemant
27. First dental book to be published in America – Richard Cotland Skinner
28. First dental chair – James Snell 1832
29. American Journal of Dental Science – 1839 A.D – First dental periodical
30 .First dental school –Baltimore dental college of Surgery –Founded By Harris and Harden
31.Rubber Dam suggested By Sanford .C.Barnum
32.First Foot /threadle engine – Morrison in 1872
33.Hydraulic Chair – Wilkerson -1877 AD
34.System of Dental nomenclature –G.V Black
35. Roentgen- discovered Xray
36. Edward kells – Demonstrates the use of Roentgen rays in dentistry
37. Weston A Price recommends the use of X-ray in RCT
38. Dr.William H Taggart –cast gold inlays
39.Castan –invented epoxy resins
40. Microwave Amplification By stimulated emission of radiation –MASER – Bell Labs’ Arthur L Schawlow and Charles H Townes
41. Theodore Maimans’s Ruby Laser- First working laser in history-May 16 1960
42. Dr.Ali Javan – First Gas laser with Helium Neon 1960
43. Carbon Dioxide Laser – Kumar Patel in 1964
44. L’Esperance –First to report clinical use of an Argon laser in ophthalmology-1968
45 .First artificial fluoridation plant at Grand Rapids ,USA
46.First water turbine hand piece by Dr.Nelson in 1954
47.First air turbine –Dr.Borden in 1957
PHYSICAL PROPERTIES OF MATERIALS
Definite and precise terms are used to describe the physical properties of dental
materials. These terms must be clearly defined in order for one to understand the
interrelationships between physical properties, structures, and composition. The
following definitions apply to metals or alloys used in the dental lab
a. Hardness. Hardness is the measure of the resistance of a metal to
indentation or scratching. It is an indication of the strength and wear ability of an alloy
b. Ductility. Ductility is the measure of the capacity of a metal to be stretched
or drawn by a pulling or tensile force without fracturing. This property permits a metal to
be drawn into a thin wire.
c. Malleability. Malleability is the measure of the capacity of a metal to be
extended in all directions by a compressive force, such as rolling or hammering. This
property permits a metal to be shaped into a thin sheet or plate.
d. Flexibility and Elasticity. These terms differ in their technical definition, but
they are very closely related.
–Flexibility is the characteristic of a metal that allows it to deform temporarily.
–The elasticity of a metal is used when it returns to its original shape when the load or force is removed.
e. Fatigue. Fatigue is the property of a metal to tire and to fracture after
repeated stressing at loads below its proportional limit.
f. Structure (Crystalline or Grain Structure). Metals are crystalline and many
of their physical properties depend largely upon the size and arrangement of their
minute crystals called grains.
(1) Grain size. The size of the grains in a solidified metal depends upon the
number of nuclei of crystallization present and the rate of crystal growth. In the practical
sense, the faster a molten is cooled to solidification, the greater will be the number of
nuclei and the smaller will be the grain size.
Generally speaking, small grains arranged in an orderly fashion give the most desirable properties.
(2) Grain shape. The shape of the grains is also formed at the time of crystallization.
If the metal is poured or forced into a mold before cooling, the grains will be in a flattened state.
Metal formed by this method is known as cast metal.
If the metal is shaped by rolling, bending, or twisting, the grains are elongated and the metal
becomes a wrought wire.
g. Crushing Strength. Crushing strength is the amount of resistance of a
material to fracture under compression.
h. Thermal Conductivity. Thermal conductivity is defined as the ability of a
material to transmit heat or cold.
A low thermal conductivity is desired in restorative materials used on the tooth
whereas a high thermal conductivity is desirable where the material covers soft tissue.