Transcript Ternopil State Medical University named by I. Gorbachevskyj Topic. Historical stages of Therapeutic Dentistry, its chapters. The value of scientific research of Ukrainian scientists. Dental instruments. Histological and clinical anatomy of the.

Ternopil State Medical University
named by I. Gorbachevskyj
Topic.
Historical stages of
Therapeutic Dentistry, its chapters.
The value of scientific research of
Ukrainian
scientists.
Dental
instruments.
Histological
and
clinical anatomy of the teeth. Dental
charting. Signs of teeth.
Department of Therapeutic Dentistry
Lecturer: Levkiv Mariana
1
2
• Dentistry has a long and fascinating
history. From the earliest times, human
beings have been plagued by dental
disease.
• Many of the remarkable techniques used
in modern dentistry can be traced to the
very earliest of times in every culture.
3
•
Therapeutic Dentistry- is a part of dentistry that studies the reasons
and mechanisms of teeth diseases, periodontium tissues diseases
and oral mucosa diseases, theirs diagnosis, treatment methods and
prevention.
•
•
•
•
•
Therapeutic Dentistry includes such chapters:
- Propaedeutic course;
- Preventive dentistry and Endodontology;
- Periodontology;
- Oral Pathology- (deals with oral mucosa diseases).
•
Propaedeutic course - deals with the history of dentistry, study the
anatomical and physiological features of the oral cavity, dental
instruments and dental office equipment, ergonomics issues, ethics
and deontology, structure of Ukraine dental service.
4
Preventive dentistry & Endodontics
• A branch of dentistry that deals with the
prevention, diagnosis and treatment of the
diseases affecting dental pulp, root and
periapical tissues.
• Restoring a tooth portion affected by dental
caries, root canal treatment of the tooth whose
dental pulp is infected etc. are some of the
commonly performed treatment procedures in
Endodontics.
5
Periodontics
• Periodontology or Periodontics is the
specialty of dentistry that studies
supporting structures of teeth, diseases,
and conditions that affect them..
6
Oral Pathology
Oral pathology is the specialty of
dentistry and pathology which deals
with the nature, identification, and
management of diseases affecting the
oral and maxillofacial regions.
7
BASIC INSTRUMENTS
• There are a few basic instruments that are
universal to almost every procedure in
dentistry.
8
Hand
instruments
Working end(s) of instruments
•Are the functional parts of the instrument
• Can have a variety of functions including: cutting,
packing, carving, placing and condensing
•Are adapted to the function of the particular instrument
•May be bevelled (i.e. the working end is cut at an angle)
• An instrument can be single-ended (one working end)
or double-ended (two working ends)
Shank of an instrument
• The part between the working end and the handle
• Can be straight or angled
• The function of the instrument determines the angle
and flexibility of the shank
Handle of an instrument
• Is the part of the instrument that the operator grasps
• Design is related to the function of the instrument
9
Set of examination instruments
Mouth mirror
Functions
• •To provide indirect vision
• •To reflect light
• • For retraction and protection of oral tissues
• • For magnification (the number of the mirror
represents size of mirror head)
10
Sickle/contra-angled probe
Functions
• • Detection of:
•
defective pits and fissures;
•
calculus;
•
deficient margins of restorations, crowns and bridges;
•
caries;
• • Examination (pointed tip allows good tactile sensitivity)
Varieties
• • Can be single-ended or double-ended
• • Many different styles available
• •Working ends may vary (straight, curved)
11
Periodontal probe
Function and features
• Measure the depth of periodontal pockets
•Tip is calibrated in millimetres
•Blunt end reduces the possibility of tissue trauma
Varieties
• Single-ended or double-ended
• Can be straight, curved or at right angles
• Plastic types available
12
College tweezers
Functions
• • Placing small objects in the mouth and retrieving small
objects from the mouth
• • Locking type ‘lock’ to prevent dropping materials
Varieties
• • Locking and non-locking types
• •Working ends can be straight, curved, serrated or smooth
13
INSTRUMENTS USED IN
BASIC RESTORATIVE
PROCEDURES
Spoon excavators
Functions and feature
• •A spoon-shaped working end for ‘spooning’ out dentinal
caries from the cavity preparation
• • Edges of working end are sharp
• Any remaining caries will be removed with the conventional
handpiece and a round bur
14
Mixing spatulas
Function and feature
• • Used to mix dental materials
• • Anodised aluminium spatula will not stick to any composite
materials or discolour materials
15
Flat plastic instrument.
Also called: plastic instrument
Functions
• •To deliver materials to the cavity preparation
• •To remove excess materials
Varieties
• •Various sizes and shapes available
• • Can be single-ended or double-ended
16
Round-ended plastic
Functions and feature
• •Used to create anatomical shapes in composite material
during restorations
• •The ball-ended plastic instrument can also be used to pack
and condense composite materials
17
Rotary instruments
HANDPIECES AND BURS
• Dental handpieces and rotary attachments
help to make dental treatment more
comfortable for the patient and reduce the
amount of time needed to complete
procedures.
18
Air turbine handpiece
Also called: fast handpiece, high speed handpiece, air rotor handpiece
Type
• Contra-angled
Functions, precaution and features
• • Removal of tooth tissue during restorations and preparation of
teeth for fixed prosthetic appliances
• • Polishing of restorations
• • High speeds create heat and friction – handpiece must be run with
water to cool the tooth to prevent pulpal damage
• • High speed saves treatment time and reduces vibration
19
Driven by
•Turbine – may need to be lubricated – check manufacturer’s instructions
• Compressed air rotates the turbine, which then rotates the bur
Speed
Check manufacturer’s specifications (can run up to 500000rpm)
Grip
Accepts friction grip attachments
Attachment
Dental unit
Varieties
• Different types of chucks available (e.g. those which need bur changing
tool)
•With or without light
• Smaller heads for difficult access
20
Straight handpiece
Functions
• • Used in surgical procedures to remove bone (cannot use air
turbine as the water is not sterile)
• • Used extra-orally at chairside or in the dental laboratory (e.g. for
denture adjustments)
Speed
• can run up to 40 000rpm
Grip
• Accepts long shank attachments
Attachment
• Electric motor that fits into the base of the handpiece
21
Slow Speed Handpieces
Type
• Contra-angled
Functions
• • Removal of caries
• • Polishing
• •Procedures that require torque
• •Refine cavity preparations and adjust occlusion
Driven by
• Gears
Speed
• The speed of the handpiece ranges from 0 to 40 000 rpm
Attachment
• Electric motor that fits into the base of the handpiece
22
Burs
Head
• This is the working end
• Function depends on the size and shape of the head
• Many different sizes and shapes, each used for a different
function (cutting, polishing and finishing)
Neck
• The part that connects the head to the shank – usually narrows
towards the head
Shank
• The part that fits into the handpiece
• Shapes and lengths vary, depending
on function
• Can sometimes be marked to identify bur type (stripes or coloured bands)
23
Some points to remember about rotary
attachments and burs
• Most often called burs, but also available are wheels, discs,
rubber points, rubber cups and stones
• Each has a particular function (cutting, polishing, finishing or
caries removal)
•Are made from various materials (tungsten carbide, diamond
and steel)
• Can have flutes (the cutting edges)
•The end of the shank determines which handpiece the
attachment will fit into:
 Long straight shank – straight handpiece
 Latch grip – conventional type/slow speed handpiece
 Friction grip shank – air turbine handpiece/high speed
handpiece
 Other various attachments such as snap or screw-type
attachments
24
Shape and function
•
•
•
•
Shape determines function; the examples that follow relate
to tungsten carbide burs:
• Rose head/round – cutting and removing caries
• Pear – to shape the cavity preparation
• Fissure – to shape and prepare the cavity preparation
25
Grip and corresponding handpiece
Refers to the way the bur’s shank is ‘gripped’ into the
handpiece
• Composition
• •Refers to the head of the bur and what it is made from
• • Generally:
•
Most latch grip burs are made of steel
•
Most fiction grip burs are made of tungsten carbide or
diamond
•
Most long shank burs are made from steel if they are meant
for surgical procedures and stainless steel if they are meant
for laboratory purposes
26
Anatomical and histological features of
teeth
1.
In adult humans there are 32 permanent teeth.
2.
These are preceded during childhood by 20 deciduous
teeth.
3.
The tooth lies in a bony socket, the alveolus, that is
covered an oral mucosa called the gingiva (gums)
Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.
27
Tooth structure
28
Enamel
• Physical characteristics of enamel
• Enamel is highly mineralised and is the hardest tissue
in the body. Enamel covers the anatomical crown of
the tooth and varies in thickness; it is semi-translucent
and its colour can vary from bluish white to hues of
yellow.
• Chemical composition of enamel
• Enamel consists of 96–97% inorganic material (by
weight), the main inorganic component being
hydroxyapatite, 1% organic material (by weight), the
main organic component being protein and 2–3% water
(by weight).
29
• Structure of enamel
• Enamel is made up of millions of enamel prisms or
rods, which run from the amelo-dentinal junction to the
enamel surface. Each prism is made up of a large
number of enamel crystallites.
30
Dentine
• Physical characteristics of dentine
• Dentine is mineralised tissue forming the bulk of the tooth. It
underlies the enamel in the crown area and is covered by the
cementum in the root area. Dentine is pale yellow in colour and is
harder than bone and cementum but not as hard as enamel.
• Chemical composition of dentine
• Dentine consists of 70% inorganic material (by weight) of which the
main inorganic component is hydroxyapatite (Ca10(PO4)6(OH)2).
Organic material constitutes 20% (by weight). The main organic
component is collagen fibres embedded in amorphous ground
substance. The remaining 10% (by weight) is water.
31
•
•
Structure of dentine
Dentine consists of many dentinal tubules that run parallel to each other,
following a double curved course, and extend from the pulp to the amelodentinal junction. Each dentinal tubule contains an odontoblast process
surrounded by intercellular ground substance composed of fine collagenous
fibrils. The odontoblast cells are a layer of closely arranged cells on the
pulpal surface of the dentine with their nuclei situated at the basal (pulpal)
end of each cell.
32
Cementum
•
•
•
•
Physical characteristics of cementum
Cementum is a pale yellow, calcified tissue covering the root dentine. It is
softer than dentine and can easily be worn away, resulting in exposure of
the dentine. Its thickness varies according to location; it is thickest towards
the apical third of the root and thinnest cervically.
Chemical composition of cementum
Cementum is 65% by weight inorganic (mainly hydroxy-apatite), 23%
organic (mainly collagen) and 12% water.
33
Dental pulp
•
Pulp is a soft vascular connective tissue occupying the
centre of the tooth. The shape of the pulp approximately
follows the shape of the outer surface of the tooth. The pulp
is made up of a pulp chamber in the crown and root canals
extending the length of the root. The shape and number of
root canals can vary considerably. At the apex of each root
is a foramen or foramina through which blood vessels, nerves
and lymphatics pass. Small projections of the pulp are found
under each cusp; these are known as pulp horns or cornua.
34
Dental pulp
•
The dental pulp is surrounded by dentine and is contained in
a rigid compartment.
•
•
•
Functions of pulp
The dental pulp has the following functions:
■ At late bell stage the cells at the periphery of the pulp
differentiate into odontoblasts forming dentine.
• ■ It provides nutrients to the odontoblasts. (trophic function )
• ■ It acts as a sensory organ especially when dentine is
exposed. The pulp rapidly responds to stimuli such as caries
and attrition by laying down reparative or reactionary
dentine. (reparative function)
• ■ It mobilises defence cells when bacteria enter it.
(protective function)
• ■ Cells proliferating in the pulpal tissue create pressure; this
is thought to play a part in tooth eruption.
35
Periodontal ligament
•
•
•
•
•
•
•
The periodontal ligament is a specialised fibrous connective tissue that
surrounds the root area of the tooth. It consists mainly of collagenous fibres.
It has the following functions:
■ It provides a support mechanism for the tooth; it cushions teeth against
excessive occlusal forces, preventing damage to the blood vessels and
nerves at the root apex.
■ It maintains the functional position of a tooth by keeping the teeth in
contact and prevents the tooth from drifting or tilting.
■ The periodontal fibres undergo continuous change. Its cells form, maintain
and repair the alveolar bone and cementum.
■ Sensors in the periodontal ligament provide proprioceptive input,
detecting pressures on the tooth.
■ The periodontal ligament has a rich supply of blood, which provides
nutrients to the cementoblasts.
36
•
The periodontal ligament is made up of two groups of fibres:
the gingival fibre groups and the principal fibre groups.
The gingival fibre groups of the periodontal ligament include:
• ■ Dentino-gingival fibres (free gingival fibres) are attached to
the cementum and fan out into the gingival tissue.
• ■ Trans-septal fibres run horizontally from the cervical area
of one tooth to the adjacent tooth.
• ■ Alveolo-gingival fibres arise from the alveolar crest and run
coronally into the attached and free gingiva.
• ■ Circumferential fibres (circular) encircle the neck of the
tooth.
37
38
The principal fibre groups of the periodontal ligament are:
• ■ Oblique fibres which run obliquely from alveolar bone to
tooth.
• ■ Apical fibres which radiate from the apex of the tooth to
the adjacent alveolar bone.
• ■ Horizontal fibres which run horizontally from the cementum
to the adjacent alveolar bone.
• ■ Inter-radicular fibres which are found between the roots of
multi-rooted teeth and run from the root to the adjacent
alveolar bone.
39
TEETH STRUCTURE
Primary
teeth
40
TEETH STRUCTURE
Permanent
teeth
41
TOOTH FUNCTION
Types
Function
1. Incisor
Incisor is a tooth that has one root;
function: to cut and cut off food.
2. Canine
Canines are the teeth that have one
root and has the function to rip the food.
3. Premolar
teeth that had two/one roots; used to
grind and chew food.
4. Molar
Molar tooth is a tooth that has two/three
roots; have a function for crushing and
chewing food.
Morphological differences between primary
and permanent teeth
•
•
•
•
•
•
•
•
•
•
There are numerous differences between the primary and permanent dentition,
many of which give rise to considerations in relation to operative treatment.
Essentially, primary teeth have:
■ A shorter crown.
■ A lighter colour.
■ Narrower occlusal surfaces.
■ Thinner enamel and dentine.
■ Relatively larger pulps.
■ Curved roots
(to accommodate the
developing permanent
successor).
Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.
43
Numbering Systems
• Universal/National System
– Developed in 1968
– Most commonly used in the United States
• Fédération Dentaire Internationale System
– Canada and European countries use this
– Easily adapted by computer and is widely
used in most countries
• Palmer System
44
Universal numbering system
A system is used in the United States, called the universal system. This is a
two-digit system but the teeth are numbered from 1 through to 32 in a
clockwise direction starting with the upper right third molar:
Right 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Upper
Lower 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 Left
45
ISO/FDI numbering system
The mouth is divided into four quadrants and each quadrant is given a
number, starting with the upper right quadrant and working in a clockwise
direction.
For example, the upper left quadrant is 2. The teeth are then allocated a
number starting from the midline, so all central incisors are 1 and all third
molars are 8. Therefore the lower right second premolar is 45.
Right 18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28 Upper
Lower 48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38 Left
46
Palmer Notation System
In this system, the dentition is divided into quadrants and the teeth in each
quadrant are numbered 1 to 8 starting at the midline. Each quadrant is
separated by a vertical line for right and left and by a horizontal line for
upper and lower. Thus |6 is the upper left first molar in the permanent
dentition. Right 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 Upper
Lower 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 Left
47
Universal/National Numbering
and Lettering System
8 9
Maxillary
right
Maxillary
left
E
F
Maxillary
right
1
16
A
17
T
Third molars
32
Mandibular
right
Mandibular
right
Mandibular
left
Maxillary
left
J
Second molars
P
O
K
Mandibular
left
Primary teeth
25 24
Permanent teeth
48
Fédération Dentaire Internationale
System for Numbering
1
Maxillary right
quadrant “1”
1
Maxillary left
quadrant “2”
1
1
Maxillary right
quadrant “5”
8
Third molars
8
8
5
8
5
Mandibular right
quadrant “8”
Mandibular right
quadrant “4”
1
1
Mandibular left
quadrant “3”
Maxillary left
quadrant “6”
5
Second molars
1
1
5
Mandibular left
quadrant “7”
Primary teeth
Permanent teeth
49
Palmer System for Numbering
1
1
Maxillary
right
quadrant
Maxillary
left
quadrant
Maxillary
right
quadrant
A A
Maxillary
left
quadrant
8
8
E
E
8
8
E
E
Mandibular
right
quadrant
Mandibular
left
quadrant
1
Mandibular
right
quadrant
A A
Mandibular
left
quadrant
Primary teeth
1
Permanent teeth
50