Recent trends in operative dentistry

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Recent trends in operative dentistry

• Include the following
• 1) Recent trends in caries diagnosis.
• 2) recent trend in caries preventiopn
• 3) Recent trends in cavity classification.
• 4) Recent trends in cavity design.
• 5) Recent trends in restorative materials.
• 6) Recent trends in restorative technique.

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Recent trends in caries diagnosis
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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.

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Recent Methods for Caries Diagnosis

• 1) Clinical examination methods. -
  intra-oral camera.
  - electrical resistance.
• - Fiberoptic transillumination.
• - Laser Based device.
• - Ultrasonic detection.
• - Dye penetration method.
• 2) Radiographic methods.

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Clinical examination methods
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• 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 .

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• 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 .

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• 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

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• 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 .

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• 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.

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• 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.

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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.

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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.
  

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A
B
A- Bitewing radiograph. B- Periapical radiograph.
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Radiographic Appearance of Caries

• Interproximal lesions

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C) Digital Imaging
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2-Electrical resistance
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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.

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Advantages

• Very effective in detecting early pit and fissure
  caries.
• It can monitor the progress of caries during
  caries control program.

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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.

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3-fiber-optical Trans Illumination (FOTI)
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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.

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3-fiber-optical Trans Illumination (FOTI)
Vertical fracture
Marginal ridge fracture
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• 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

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Disadvantages

• It is subjected to inter and intra observer
  variations
• Difficult to locate the probe in certain areas

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4-laser Auto Fluorescence (LAF)
B) Diagnodent
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B) Diagnodent
4-laser Auto Fluorescence (LAF)

• 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.

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A photograph showing diagnodent instrument
during caries diagnosis
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Recent Methods for Caries Diagnosis

• Radiographic methods.
• Electrical resistance.
• Fiberoptic transillumination.
• Laser auto fluorescence.
• Ultraviolet illumination.
• Endoscopy.
• Ultrasonic detection.
• Dye penetration method.

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8-dye Penetration Method
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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.

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8-dye Penetration Method

• Dyes should fulfill the following criteria before
  being recommended for clinical use
• Absolutely safe for intra oral use.
• Specific and stain only the tissues it is
  intended to stain.
• Easily removed and not lead to permanent
  discoloration.

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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.

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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.

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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.
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Advantages
It is simple method for caries diagnosis
Disadvantages
It may compromise the bond strength of bonded
restorations
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• 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 .

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Recent trend of cavity classification

• The traditional GV blacks classification
• It was concerning the site of caries
• and not the size of lesion.
• New classification proposed by mounthume has
  been introduced at 1977
• This new classification concern the site and
  size of the lesion through the following
  scale.

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• site/stage (si/sta) classification.

size site 0 No cavity 1 minimal 2 moderate 3 enlarged 4 extensive
1- pit fissure. 1.0 1.1 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
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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.

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• 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

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• 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.

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(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.

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• 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.

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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.

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• 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.

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• 2) Tooth- colored restorations
• A- composoite resins
• a) indirect resin composite e.g. articlass
  and ceromers .
• cured extra-orally by post-curing using heat
  and light.
  
  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 .

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• 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.

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• 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.

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• B) Glass ionomer
• a) Resin modified glass ionomer.
• contain resin more than ionomer.
• b)

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Thank you