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Recent trends in operative
dentistry
Include the following :
1) Recent trends in caries diagnosis. (1
2) recent trend in caries preventiopn (2
3) Recent trends in cavity classification. •
4) Recent trends in cavity design. •
5) Recent trends in restorative materials. •
6) Recent trends in restorative •
technique.
Recent trends
in
caries diagnosis
Introduction
• A single test for caries diagnosis usually
cannot be used alone, because such test
may be insufficient for accurate caries
diagnosis.
• Recently, many methods and devices
have been introduced into the field of
dentistry to aid in earlier diagnosis for
carious lesions and in turns preserving
as much tooth structure as possible.
Recent Methods for Caries Diagnosis
1) Clinical examination methods.
- intra-oral camera.
- electrical resistance.
- Fiberoptic transillumination.
1. - Laser Based device.
2. - Ultrasonic detection.
3. - Dye penetration method.
2) Radiographic methods.
Clinical examination methods
b) Advanced methods :
1) The intra-oral camera .
Image of the teeth of exceptional quality with improved lighting and
magnification appear on a monitor of computer.
It also improve visual access to the dental cavity.
2) Caries detection dye.
this was applied to differentiate between the superficial infected
carious dentin and reversibly denatured re-mineralized affected
dentine , which could be left without removal.
3) laser based devices :
a) laser fluorescence : diagnodent (fig.2).
b) Co2 laser.
a) Laser fluorescence:
this device have two fiber-optic diodes,; one for emits pulsed light of
655 nm wavelength used to scan over the fissure area in a sweeping
motion .The other ,used to receives the reflected fluorescent light ,
where any changes caused by demineralization are assigned as a
numeric value. this device works on the fluorescing nature of bacterial
metabolic by products .
a) laser fluorescence ( Diagnodent). •
- Healthy tooth structure exhibits little or no fluorescence,
resulting in very low reading on the display screen.
- If the general numeric data between 5 and 25, indicate initial
lesion in the enamel while values greater than that indicate
dentinal caries.
b) Co2 laser .
because caries has increased water and carbon contents
with decreased minerals, it is very sensitive to Co2 gas laser.
- when caries is exposed to Co2 gas laser its water contents
will evaporized leaving black carbonized residue .
4) Digital fiber optic trans-illumination.
it is a qualitative diagnostic methods by which teeth
are illuminated through light transmit from lingual
surface.
- digital fiber optic was introduced to replace the
conventional way of fiber optic trans-illumination ,
where the former can detect the incipient caries,
frank caries , and cracks using charged couple
receptor. This receptor contains
a photocells which convert the photon energy into
color values . In this way the caries will appear as
shadow on the monitor of computer
5) Electrical caries monitor.. •
it is based on the electrical conductivity
differences between sound dentinal tissues and
caries dental tissues. The device has small electrode
to hold by patient and another fine point to be placed
on the tooth to explore the fissure
- the recording dial shows number from 0 -10
when the value exceed 5, this indicate sufficient
demineralization .
6) ultra sonic caries detection. •
in dentistry, ultrasound has been
used to image the tooth and to find
caries lesion on smooth surfaces .
- there is a great promise for ultra sound
caries detection for approximal surface.
II) Radiographic examination. •
a - Traditional x-ray.
b - Computerized radiograph ( digitizers).
a) Traditional x-ray.
- periapical
- bite wing
- oclusal.
b) digitizers:
- scanning usual radiographs.
- direct: using R.V.G.
- indirect; using Digora.
A)Traditional x-ray
a) Periapical film: caries appear as •
radiolucent area .
b) Bitewing x-ray: specially to detect •
proximal caries.
c) Occlusal film : to detect the teeth in •
occlsion.
B) digitizers
a) Scanning usual radiographs.
analyzing the degree of radiolucency of the carious lesion to
estimate its extent by subtracting old from new radiographs.
b) Direct using R.V.G. :
there is no film but a special intra-oral sensor is used instead
of the conventional x-ray to transmit the image to a computer
monitor.
c) Indirect using Digora :
depends on reusable image plate which contain storage –
phosphor based.
when exposed to radiation create a latent image .
when this latent image is exposed to a laser scanning it will
obtain the stored information.
A
B
A- Bitewing radiograph.
B- Periapical radiograph.
Radiographic Appearance of Caries
• Interproximal lesions
C) Digital Imaging
2-Electrical
resistance
2-electrical Resistance
• The electrical conductivity is directly
proportional to the amount of
demineralization.
• It is expressed numerically on a scale
from 0-9, indicating the change from
sound tooth to an increased degree of
demineralization.
Advantages:
• Very effective in detecting early pit and
fissure caries.
• It can monitor the progress of caries
during caries control program.
Disadvantages:
• Presence of enamel cracks may lead to
false positive diagnosis.
• A sharp metal explorer may cause
traumatic defects.
• Full mouth examination is time
consuming.
• It can only recognize demineralization
and not the caries specifically.
3-fiber-optical Trans Illumination (FOTI)
3-fiber-optical Trans Illumination
(FOTI)
• Fiber-optical trans illumination was
initially designed for the detection of
proximal caries.
• It works under the principle that since a
carious lesion has a lowered index of
light transmission, an area of caries
appears as a dark shadow that follow
the spread of decay through the dentin.
3-fiber-optical Trans Illumination (FOTI)
Marginal ridge fracture
Vertical fracture
Advantages
:
•
•
•
•
No hazards of radiation
Simple and comfortable to the patient
Lesions, which cannot be diagnosed
radiographically, can be diagnosed by
this method
Not time consuming
Disadvantages:
•
•
It is subjected to inter and intra
observer variations
Difficult to locate the probe in certain
areas
4-laser Auto Fluorescence (LAF)
B) Diagnodent
4-laser Auto Fluorescence (LAF)
B) Diagnodent
• This instrument is based on the laser auto
fluorescence principle but without the use of
dyes.
• The excitation light is transmitted by an
optical fiber to the tooth, and a bundle of
nine fibers arranged concentrically around it
serves for detection.
• The digital display shows quantitatively the
detected fluorescence intensity.
A photograph showing diagnodent instrument
during caries diagnosis
Recent Methods for Caries Diagnosis
1.
2.
3.
4.
5.
6.
7.
Radiographic methods.
Electrical resistance.
Fiberoptic transillumination.
Laser auto fluorescence.
Ultraviolet illumination.
Endoscopy.
Ultrasonic detection.
8.
Dye penetration method.
8-dye Penetration Method
8-dye Penetration Method
•
•
Dyes can visualize a subject from its
background.
For qualitative assessment, it is
sufficient to differentiate colored
objects from the non colored ones.
8-dye Penetration Method
 Dyes should fulfill the following criteria
before being recommended for clinical
use:
1. Absolutely safe for intra oral use.
2. Specific and stain only the tissues it is
intended to stain.
3. Easily removed and not lead to permanent
discoloration.
A) Dyes for Detection Carious Enamel:
Various dyes have been tried to detect
carious enamel, each have some advantages
and disadvantages.
• Procion dyes stain enamel lesions but the
staining become irreversible.
• Calcein dye makes a complex with calcium
and remains bound to the lesion.
• Brilliant blue has also been used to
enhance the diagnostic quality of fiber-optic
trans illumination.
B) Dyes for Detection of Carious Dentin:
• 0.5% Basic fuchsin in propylene glycol has
been proved to be successful in detection of
carious dentin.
• Basic fuchsin dye was considered to be
carcinogenic; therefore it has been replaced
by acid red and methylene blue.
• Methylene blue is also slightly toxic so acid
red is preferred.
Dyes for Detection of Carious Dentin
A
B
A) Detail of caries in dentin identified with caries detector.
B) Detail of the preparation following caries removal.
Advantages:
It is simple method for caries diagnosis
Disadvantages:
It may compromise the bond strength
of bonded restorations
Recent trend in caries prevention. •
1) Caries vaccine (caroRx). •
- By using tobbaco planets through injecting them with human DNA
to produce human proteins which contains a serum
immunoglobulin A antibody ( plantibodies).
- Effect of this vaccine lasts for at least 4 months.
2) laser radiation:
- Infrared laser radiation may increase the acid resistance of enamel
by melting a thin layer of surface enamel , which cause water
evaporation and distribution of minerals in all lasered area .
- This acid resistance can enhanced by fluoride application.
3) healozone :
- ozone deactivates ₉₉% of the bacteria in 10 sec.
- acids from bacteria are thus largely neutralized .
- minerals and fluorides is now easy to supplied .
- re-mineralization process occur within 4 – 12 weeks .
Recent trend of cavity
classification
The traditional GV black’s classification
It was concerning the site of caries
and not the size of lesion.
New classification proposed by •
mount&hume has been introduced at
1977
This new classification concern the site •
and size of the lesion through the
following scale.
site/stage (si/sta) classification.
size
site
1- pit &
fissure.
0
No
cavity
1.0
1
minimal
1.1
2
moderate
3
enlarged
4
extensive
1.2
1.3
1.4
2- contact
area
2.0
2.1
2.2
2.3
2.4
3- cervical
3.0
3.1
3.2
3.3
3.4
Recent trend in cavity preparation.
Minimal invasive a traumatic technique •
and produced a cavity with small
dimensions (conservative design)is the
logic concept which go with the general
progressions regarding instruments,
equipments, and restorative materials.
The followings are some of advanced •
tech. used to produce a conservative
cavity design.
Change the concept of G.V.
Black(extension for prevention) into the
concept of minimal intervention
dentistry has evolved as a consequence
of our increased understanding of the
caries process and the development of
adhesive restorative materials.
a) Dental caries is a reversible cycle
where the initial demineralization can
remineralized
b) bonding technique allowing for
conservative cavity designs
The concept of conservative approach is to •
remove the defect only without any more
extension, with respect all
mechanical and biological principles.
1) Air abrasion technique.
- it was developed in 1940,
The first modification was in the last two decades with introduction of kinetic
cavity preparation 2000 ( KPC 2000). - too small minute particles are carried to the tooth by a stream of air which precisely
spraying away the decay only.
(2) chemico-mechanical gel(crisolve).
Gel consist of 3 amino acid plus sodium •
hypochlorite is applied into the decayed
area to dissolve and get it easily
removed manually using suitable
excavator.
3) Yag. type laser •
used to remove organic and inorganic •
debris of caries tissue. It vaporizes the
carious tissues and left the sound tooth
structure.
4) prefabricated size matching ceramic inlays •
( sonic sys).
This system is consist of : •
Varying sizes of abrasives tips are operated in •
oscillating ultrasonic. Movement. This system
include standardized ceramic inlays matching
the sizes of abrasive tips.
Recent trend in restorative
materials.
1) Metallic restoration.
a) bonded amalgam. •
- It is a conventional amalgam with 4-META •
bonding system.
- bond strength is low. •
b) Gallium based silver alloys. •
- They were introduced to the dental field in a trial
•
to replace the mercury containing silver amalgam
- Despite of its high polish ability, it has a higher
•
corrosion more than high copper amalgam.
- supplied in specially designed capsules and an •
adhesive bonding to be applied after acid etching.
Metallic restorations •
3) mercury-free direct filling alloys
•
It is based on silver-tin particles coated with silver •
that can be self welded by compaction to build up a
restoration.
4) computer designed amalgam powder:
Depend on the idea that if alloy particle sizes are •
packed together well , it will be possible to minimize the
mercury required for mixing.
•
2) Tooth- colored restorations;
A- composoite resins:
a) indirect resin composite e.g. articlass and ceromers . •
curedextra-orallybypost-curingusingheatandlight.
•
b) B-quartz or mega-fill ceramic inserts:
- are an attempt to counteract some of the low •
mechanical properties of resin composites by decreasing
polymerization shrinkage and increasing wear resistance
of the restoration.
Beta quartz inserts are formed from silica-based glass
•
which can chemically bond to resin composite by silane
coupling agent .
c) Ormocers: •
it is an organically modified ceramics. •
d) smart composite.
- it is an ion-releasing composite
material.
- it releases fluoride, hydroxyle, and
calcium ions as the pH drops
- it inhibit bacterial growth because it
include alkaline glass filler.
e) flowable composite resins. •
because they have lower filler
•
volumes .they are used in class V or
as a liner under posterior composite
f) new polymer composite:
nano-composite is made from tantalum
oxide and silica nano- particles fillers
incorporated in a liquid crystal matrix.
B) Glass ionomer: •
a) Resin modified glass ionomer. •
contain resin more than ionomer. •
b) •
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