HISTORY AND RATIONALE OF OPERATIVE DENTISTRY

1. History and
rationale of
operative dentistry
DR. AJAY BABU GUTTI
PG 1ST YR

2. Operative dentistry is the art and science of diagnosis,
treatment, and prognosis of defects of teeth that do not
require full coverage restorations for correction. Such
treatment should result in the restoration of proper tooth form,
function, and esthetics while maintaining the physiologic
integrity of the teeth in harmonious relationship with the
adjacent hard and soft tissues all of which should enhance
the general health and welfare of the patient.
OPERATIVE DENTISTRY
- Sturdvent

3. Past is a history- a common saying in English- but the question
is “can we forget the past or rather should we forget the past?”
WINSTON CHURCHILL’s phrase is a befitting reply. He said,
“The longer you look back, the further you can look forward.”
It is a fact that one cannot evaluate the problem of present
without knowing the past. Same is true with dentistry and
precisely Operative Dentistry.
INTRODUCTION

4.  The history of operative dentistry dates back to the era
when Babylonians, Assyrians, and Egyptians (4500–
4000 BC) were familiar with gold, and Etruscans and
Phoenicians (2700 BC) were practicing gold crowns

5.  Since then, there have been numerous advances,
developments, and researches which have proceeded
continuously.
 These inventions have transformed the practice of operative
dentistry into one which is more efficient and more
comfortable for the patients as well as for the operating team

6. 18 TH CENTURY
 The field of operative dentistry embraced all of chairside
dentistry during the 18th century.
 It was during this period when maximum progress in the field
of dentistry was observed

7. 19 TH CENTURY
 By the beginning of 19th century, dentistry was no
longer in the hands of barbers/artisans but was
practiced by professionally minded dentists or
surgeons

8. 20th century
 With the beginning of the 20th century, there
came many refinements and improvements
in quality of various materials and processes
used in restorative dentistry.
 Physical and mechanical tests combined
with fundamentals of engineering science
were applied to structure designs and
restorative materials.
 Shortcomings of materials were recognized
and improved by the advent of newer
technology.

9. 1. Analgesia and anesthesia
2. Etiology, diagnosis and treatment regimes
3. Equipment and devices
4. Direct restorative materials
5. Indirect restorative materials
6. Illumination and magnification
A number of significant occurrences in the history
of operative dentistry can be studied by grouping
them into the categories of

10. 1. Anesthesia and Analgesia
 The first ever recorded use of any anesthetic agent dates
back to 500 AD, when Peruvians used Coca leaves for
psychotropic properties

11.  In 1842 Dr. Crawford used Ether as anesthetic

12.  In 1884, Carl Koller discovered the analgesic properties of
cocaine.
 Shortly after, in that same year of 1884, William S. Halsted
introduced conduction anesthesia by using cocaine to block
the inferior alveolar nerve. Although cocaine was effective for
achieving profound anesthesia, it proved to be highly
addicting.

13.  In 1904 procaine was synthesized by Einhorn
and Uhfelder in Germany. When mixed with a
very small proportion of epinephrine, this agent
was found to be highly effective and safe as a
local anesthetic agent for most patients.
 Procaine was widely used by physicians and
dentists into the 1950s and Novocaine is still the
name that patients commonly associate with
local anesthetics.

14.  By the 1950s, lidocaine became widely accepted by
the dental profession.
 It was found to have extreme safety, surpassing that
of Novocaine, and lidocaine became a widely used
anesthetic agent.
 Although many other local anesthetic agents are
currently in use and nitrous oxide is often used for its
analgesic effect, lidocaine remains the principal
anesthetic in routine use

15. 2.Etiology, Diagnosis, and Treatment Regimes
 Pierre Fauchard was the first who suggested humoral
imbalance as the main cause of tooth decay and described its
prevention.
 Before the middle of 19th century, there was no scientific
basis for the causation of dental caries and infection control.

16.  Louis Pasteur in 1865 concluded that microorganism caused
putrefaction and could be transferred from one place to other
by means of solids, liquids, or airborne particles.
 During his work, he found that some microorganisms could be
destroyed by heat or other methods and also provided the
basis for the “germ theory” of infection.
 Robert Koch cultured, separated, and classified the
microorganism and hence discovered that bacilli caused
cholera and tuberculosis

17.  In 1890, Miller introduced the chemicobacterial theory of dental
caries.
 In late 19th century, the concepts of microbiology and infection were
established in medical and dental fields.
 The importance and methods of sterilization of dental instruments
were promoted by the American Dental Association and recorded
saturated steam under pressure, best method for the sterilization of
dental instruments

18.  The venerable G.V. Black was almost single-handedly
responsible for the development of the scientific cavity
preparation, his work being published in 1891
 Although preceded in his work on dental nomenclature by
others, Black was the major author of the modern system of
nomenclature, presented in 1893.

19.  Another significant advancement for operative dentistry was
the introduction of dental hygienists.
 This occurred in 1906 by Dr. Alfred Fones, who established
his own school of dental hygiene With the addition of a dental
hygienist, the dentist was free to perform more operative
procedures and had a valuable auxiliary to aid in the
treatment and education of patients.

20.  By 1874, it was recognized that fluorine had a preventive
effect on dental caries.
 This recognition was to have far-reaching effects. During the
first three decades of the 1900s, Dr. Frederick McKay of
Colorado Springs observed that mottling of enamel was
confined to specific geographical locations.

21.  McKay and Dr. Dean showed that fluoride that was naturally
occurring in water caused the mottling.
 Later, Dean demonstrated that by adjusting the level of
fluoride in community water supplies to one part per million,
mottling could be reduced or eliminated and yet the caries
rate was much reduced.
 This classic work led to the widespread fluoridation Of
community water supplies throughout the United States.

22. 3.Equipment and Devices
 Evidence showed that ancient cultures used primitive drills,
trephines, files, and other devices to prepare adequate
cavities in teeth.

23.  In early 17th century, hand-rotated instruments which
had clockwise rotating drill were used to make round
ornamental cavities in decayed teeth.

24. POWERED CUTTING INSTRUMENTS
 EARLY DRILLS were
powered by hand. They
were of 2 types :
a) Straight hand drill
for direct access
preparation.
b) Angle hand drill for
indirect access
preparation.

25. They were modified to ROTATORY HANDPIECES. 25
Belt-driven straight handpiece
Gear-driven angle
handpiece
Gear-driven angle hand piece for
cleaning & polishing procedures

26.  In 1874 most significant
development was the introduction
of ELECTRIC MOTOR with 1000
rpm.
 In 1914 it was incorporated in
dental unit.
 Initial handpiece equipments
operating speed was maximum of
5000rpm.
 Then in 1946 all the old units were
converted to high speed of
10,000rpm.
26
w-Foot control with rheostat
x- Belt-driven straight handpiece
y-Three-piece adjustable
extension arm
z-Electric motor

27.  By 1950 speed of 60,000rpm and
above had been attained by newly
designed equipment's employing
speed-multiplying internal belt
drives.
 In1955 Page-Chayes handpiece
was the first belt-driven angle
handpiece to operate successfully at
speed over 1,00,000rpm.
27
Page-Chayes handpiece

28. In 1955 another major breakthrough was the introduction of contra angled handpieces with
internal turbine drives in contra angle head.
 They are of 2 types:
a) Water driven
(Turbo-Jet portable unit . A
small turbine in the head of
angle handpiece is driven
by water circulated by a
pump housed in the mobile
base.)
28

29. b) Air-turbine handpiece
Borden Airotor handpiece
(First clinically successful air-turbine handpiece.)
Air-turbine straight handpiece with attached motor
at the end of handpiece.

30.  Dr. Sanford C. Barnum blessed the field of operative dentistry
with his discovery of rubber dam in 1864.
 It was undoubtedly one of the best methods for providing
isolation from saliva and soft tissues during the placement of
restorations

31.  The first machine made burs known as Revelation Burs were
introduced by S.S. White Company in 1891.
 These machine-made steel burs were later replaced by
carbide burs when Acheson discovered a technique for
making an industrial abrasive composed of silicon carbide in
1891.

32.  Josiah Flagg in 1790 invented first dental
chair with adjustable headrest and
extended armrest for holding instruments.

33.  Morrison introduced his first dental chair in 1867 with a wide
range of adjustments. The first pump type hydraulic dental
chair called the Wilkinson chair was introduced in 1877.

34.  In 1954, Dr. Sanford S. Golden et al. were geared toward sit
down dentistry and developed a reclining chair which would
allow dentist to sit while performing various restorative
procedures.
 Since then, there is continuous improvement in the design of
dental chair to provide better comforts to the patients and
doctor.

35.  Modern diamond bur was purposed by Drendrel in 1932,
whereas tungsten carbide dental bur was marketed in 1947.
 Electric high-speed handpieces have now been developed which
have surpassed the merits of air-driven high-speed handpieces.
 Further advances in the dental equipment such as fiber-optic
handpiece, smart prep burs, chemical vapor deposition burs,
fissurotomy burs, ultrasonic devices, laser systems, and ozone
unit have been added to the literature, and research is still going
on.

36. 4.Direct Restorative Materials
 Direct restorative materials are those that can be placed
directly in the prepared tooth cavity during a single
appointment. During ancient time, the restorative materials
were obtained from bone and ivory and later these included
waxes, gums, alum, honey, ground mastic, powdered pearl,
lead, tin, gold, amalgam, gutta-percha, silicate cement, resins,
glass ionomer cement (GIC), etc

37. August Taveau of Paris combined silver and mercury to form silver
paste in 1826 and resulted in beginning of dental amalgam, an
outstanding development in the field of operative dentistry
The amalgam was later introduced commercially into the United
States in 1833 by Crawcour brothers by cutting silver from coins
and adding excess mercury
Dental profession remained hesitant about the use of Amalgam
until Black suggested a balanced amalgam formula (silver 72.5%
and tin 27.5%) in 1895.
To overcome the drawbacks of low copper amalgam alloy, Dr.
William developed high copper amalgam in 1963 which
enhanced the long-term marginal integrity

38.  Gold foil was first introduced in America by Robert in 1795
and was one of the earliest materials available for restoration
of teeth.
 Arthur discovered cohesive gold foil in 1855.This was the
major advance of dentistry.
 Gutta-percha was discovered in India in 1842.
 In 1848, Hill advocated the use of gutta-percha along with zinc
oxide eugenol as temporary filling material.

39.  Zinc oxychloride cement was purposed in 1860 and was used
as temporary filling material in spite of its low quality.
 To overcome this, zinc phosphate was introduced in dentistry
in 1879, which exhibited improved properties to be used as a
filling material and as cement.
 Silicate cement was introduced in the United States in the
late 19th century and early 20th century. Silicate was the first
tooth-colored material used in esthetic dentistry. Along with
advantage of high fluoride release, the silicate cement had
disadvantages of its solubility, pulp irritation potential, and
desiccation.

40.  To overcome the problems of silicates, direct-filling methyl
methacrylate resins were invented in 1947.
 Although they provided esthetic restorations but did not last
long because of their inherent higher coefficient of thermal
expansion and polymerization shrinkage which eventually led
to marginal leakage, postoperative sensitivity, secondary
caries, and interfacial staining.
 To improve these drawbacks, filler particles were added, but
fillers could not bind with the matrix and remained separated.

41.  A great discovery by Dr. Michael Buonocore of phosphoric
acid to increase mechanical bonding of resin to enamel in
1955 opened new gates in the world of bonding resins and
cosmetic dentistry.
 The efforts and experiments by R. L. Bowen led to the
invention of composites in 1962, which nearly obsolete the
use of silicate and acrylic resin from esthetic dentistry. With
the introduction of ultraviolet light-curing system, the cosmetic
dentistry became more convenient and efficient.

42.  Another significant advancement in the development of dentin bonding
agent aided retention and stabilization of a tooth-colored restoration
without excessive removal of sound tooth structure.
 Bonding resin is an unfilled or semi filled resin which matches to the resin
in the composite but has a lower viscosity to permit easy flow and
penetration.
 Bonding agents are categorized into “generations” according to their
evolution. First and second generations bonding agents were developed
as a single-step application, whereas the third generation came with three
steps included conditioning, priming, and application of bonding agent.
 Fourth generation came with concept of “hybridization” proposed by
Nakabayashi et al., in which diffusion and impregnation of resin into
partially decalcified dentin followed by polymerization created a resin-
reinforced layer or the “hybrid layer.

43.  Fifth generation dentin bonding agents were based on
hybridization and wet bonding technique and advantage of
having high bond strength.
 To improve the bond strength and to make the manipulation
easy; sixth and seventh-generation adhesive agents have
been tried and still are popular in adhesive restorative
dentistry.
 Composite materials were further improved by modifying the
resin matrix and filler, which resulted in the introduction of
microfilled, hybrid, microhybrid, flowable, packable, and
modified hybrid composites.

44.  GIC was developed in 1968 and first described and named by
Wilson and Kent in 1971. The GIC has been evolved from
silicate and polycarboxylate cement and thus acts as a
potential replacement for the silicate cement. Due to its
adhesion to enamel and dentin and fluoride release for
anticariogenic effect, it gained popularity widely in dental
profession.
 To improve the abrasive resistance, GIC was modified by
addition of silver to develop miracle mix or silver cermet by
Simmons in 1983.

45.  After that, McLean and Gasser introduced Glass Cermet by sintered
glass and metal powders to improve wear resistance and flexural
strength in 1985.
 Resin-modified glass ionomer cement was developed by addition of a
hydroxyethyl methacrylate monomer in the polyacrylic acid and their
polymerization is initiated along the methacrylate group after exposure
of light.
 More advancements and modifications in the composite and glass
ionomer restorative materials aided more benefits in the field of esthetic
dentistry.

46. 5. Indirect restorative materials
 Indirect materials are those that can be used
to fabricate restorations in the dental
laboratory and then are placed in or on the
teeth
 Placement of indirect materials generally
requires two or more visits to complete the
restoration.

47. • John greenwood was the first who used plaster of
paris as impression material.
• Inflexibility caused fracture upon removal.
• Developed by Charles stent in 1857
• Improves the drawbacks of gutta percha , pop and
provided with stability , plasticity, strengthen and red
colouration.

48. Alphons poller introduced reversible hydrocolloid in dentistry in 1925
Sears promoted agar hyrocolloid for taking impressions in fixed partial denture
In 1953, polysulfide impression materials were came to the operative
and prosthodontic dentistry. Then, the discoveries of polyethers,
condensation silicone, and addition silicone offered more stable and
less messy materials to dentistry

49.  Then, art of casting was introduced in Egypt (2500 BC) where lost wax
molding process was first developed for gold casting.
Nowadays, CAD/CAM system is being used for making inlays and onlays
of high strength and with more accuracy. First, chairside ceramic inlay was
made in 1985 using CAD/CAM device which was two-dimensional, but in
2000, Cerec 3 was introduced with three-dimensional graphics.

50. Illumination and Magnification
 In ancient days of dentistry, only natural light was the source
of illumination. After that, artificial lights used were from
candles and kerosene lamps.
 First, patient lights were purposed in the early 20th century
after the invention of electricity. Intraoral illumination was
enhanced in surgeries with the help of miner-type headlamps
and later by small headlamps.
 For retraction and visualization, mouth mirrors were
introduced in the 1800s, which was further improved to front
surface mirrors.

51.  Dutch businessmen, Hans and Zacharias invented first
microscope (simple and compound) and after that Robert
Hook and Leeuwenhoek used microscope for their work.
 In the middle of 19th century, Carl Zeiss, Ernst Abbe, and Otto
Schott developed the surgical operating microscope in
practice of medicine.
 In earlier days of dentistry, magnifying lenses were tried to
examine teeth intraorally for gold margins, fissures, and
cracks.

52.  The magnification provided was not sufficient, and then plastic
loupes were assembled with eyeglass frames. These loupes
became heavier as the magnification increased and to prevent
occupational stresses
 Dr. Harvey Apotheker and Dr. Jako brought the concept of
extreme magnification in the form of a dental operating
microscope in dentistry in 1978.

53.  In 1999, Dr. Gary Carr purposed the first ergonomically
configured operating microscope with Galilean optics for
routine dental clinical procedures.
 Various addition in microscopic accessories have been
occurred from 2000 onward such as beam splitter, camera,
liquid crystal display screens, video camera, and high
definition cameras. Some practitioners use loupes, loupes in
conjunction with headlamps, and endoscopes as an
alternative to operating microscope according to their ease of
handling and visibility of operating field.

54. RATIONALE OF OPERATIVE DENTISTRY

55. GOALS OF OPERATIVE DENTISTRY
 There are 4 goals or aims
1. PREVENTION: The most significant result of preventive
dentistry has been the communal fluoridation. Research and
experience have shown that trace amount of systemic fluoride,
tested mostly as an additive to water supply, significantly
reduced the incidence of dental caries (40-60%).
 Other forms can be : General health.
: Immunization.
: Antimicrobial agents.
: Diet control.
55

56. : maintaining oral hygiene
: Restoring tooth.
: Pits & fissure sealants.
: Atraumatic restorative
technique.
The taxonomy of preventive dentistry is:
PRIMARY PREVENTION (prepathosis)
- Fluoride therapy
- Diet control
- Plaque control
- Sealants
- Pulp protection etc.

57. SECONDARY PREVENTION (intervention)
It involves services of :
- Restorative dentistry
- Periodontics
- Orthodontics
- Other fields
- TERTIARY PREVENTION (Replacement)
It involves services of :
- Fixed prosthodontics
- Removable prosthodontics
- Maxillofacial prosthetics.

58. 2. INTERCEPTION :
It can be achieved by:
a) Change in patient home care
habits.
b) Removal of carious tooth tissue.
c) Altering tooth form through
restoration or selective
recontouring
d) Enhancing occlusal stability.
A positive contribution to the patients oral health is made through
such interceptive treatment.

59. 3. CONSERVATION:
Now a days it is an important concept in restorative procedure.
It can be achieved by:
a) Instrumentation approach for removal of
carious tissue.
b) Design of cavity preparation to retain as
much sound tooth tissue as possible.
c) Maintain vitality of pulp and health of
supporting tissue.
d) Preservation of oral tissues , their function
and health prevades the principles of
operative dentistry.

60. Although tooth preparation for operative procedures originally adhere to
the concept of “extension for prevention”, increase knowledge of
prevention methods , advanced clinical techniques & improved restoration
material have now provided a more conservative approach.
More conservative approaches are available for :
a) Many typical restorative procedures.
b) Diastema closure.
c) Esthetic or functional correction of malformed,
discolored & fractured teeth.
d) Actual replacement of teeth.

61. When compared to past treatment modalities these newer approaches
result in significantly less removal of tooth structure.
The primary result of conservative treatment is retention of more intact
tooth structure and less trauma to pulp tissue and contiguous soft tissue.
Stronger tooth structure
Restoration easily retained

62. Offer greater esthetic potential
Causing less alteration in intra or inter arch relationship.
4. RESTORATION:
Reestablishment and maintenance of health, form, function & esthetics are goals of
restorative treatment.
These goals pertain to – Teeth.
- Surrounding tissues.
- Entire masticatory system.

63. Other needs for restoration are:
- Carious lesion.
- Replacement or repair of restoration.
- Fractured teeth.
-As a part of fulfilling other restorative need.
-Tooth may be restored in the preventive
sense.

64. Function and Purpose
 An understanding and appreciation for infection control.
 Examination not only the affected tooth but also the oral and
systemic health of the patient.
 Diagnosis of the dental problem and must be correlated with
other bodily tissues.
 A treatment plan that has a potential to return the affected
area to a state of health and function.

65.  An understanding of material to be used to restore the
affected area with a realization of both the material limitations
and demands.
 An understanding of the oral environment into which the
restoration will be placed.
 To understand the biological basis and function of the various
tooth components and supporting tissues although the
knowledge of correct dental anatomy.

66. CONCLUSION
 During the beginning of dental science, dentistry was merely
an art practiced by barber-surgeons or artisans. With the
advent in science and technology, dentistry came into hands
of professionally minded dentists/surgeons.
 Slowly and gradually operative dentistry came out as one of
the major branches of dentistry and dentists started oriented
toward restoring and preserving of teeth.
 With the innovations and discoveries of new equipment,
techniques, materials, and methods, operative dentistry
continues to enriched, refined, and grow toward bright future

67. REFERENCES
 Sturdavent et al : art & science of operative dentistry : New
York , 2002.
 Marzouk (M.A) : operative dentistry, Modern Theory &
Practice : Washington University, 1997.
 Gilmore : Operative Dentistry, Texas , 4th edition.
 Vimal K Sikri : Text book of Operative Dentistry :
Amritsar, 1st edition.
 Peter Soben : Essentials of Preventive & Community
Dentistry : Mangalore, 2000.
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68. Thank you…..