New Advances in Caries Removal
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Transcript of New Advances in Caries Removal
New Advances in Caries Removal
Dr Wael Al-OmariBDS, MDentSci, PhD
Caries Removal
Drawbacks of Conventional Methods: Contamination and cross-infection The need for presterilisation cleaning. 1-Manual cleaning of burs 2-Washer disinfection. 3-Ulrasonic cleaners with enzymatic detergents Removal of infected and unaffected tissues. - Is total caries removal necessary? Noise, vibration and discomfort experienced with
burs.
Rational behind New Developments
Removal of only infected dentin Reduce patients anxiety Provide favorable surface features for bonding Reduce contamination and cross-infection Reduce the need for anesthesia Easier recognition between infected and
uninfected dentin Provide equal or superior efficiency compared
to conventional methods Reduce cost.
New Developments in Caries Removal
Lasers Air Abrasion (Kinetic Cavity Preparation) Polymer Burs Micropreparation Burs. Photoactivated Disinfection Carisolv Gel Atraumatic Restorative Treatment. Caries-Detector Dyes
Lasers Early Lasers (Caron dioxide, ruby and
Nd:YAG): 1- Inefficient cutting 2- Excessive heat generation 3- More efficient for soft tissue surgery.
Nd:YAG laser ablated dentin showing craters and cracks and heat induced
band (Lin et al, 2001)
Erbium Lasers
Erbium yttrium aluminum garnet (Er:YAG, 2.94 µm wavelength)
Erbium chromium yttrium scandium gallium garnet (Er,Ch:YSGG, 2.78 µm wavelength)
Mechanism of ablation by erbium lasers
Thermomechanical Ablation - High absorption coefficient in water and high affinity for hydroxyapatite. - Absorbed heat cause microexplosions and microfragmentataion of target issue. - Irradiated surface demonstrate microirregularities, absence of smear layer, open tubules, absence of extensive thermal effects.
Cavity prepared with erbium laser
Bur cut versus Er,ch:YSGG laser cut dentin (Ekworapoj et al, 2007)
Advantages of erbium lasers
No thermal effect on target tissues and pulp.
Noiseless, no vibrations. No harmful effect on the pulp. Distinguishing between infected and
uninfected dentine might be possible. Various clinical applications:
periodontics, endodontics, operative dentistry.
Disadvantages of erbium lasers
Cost Erbium laser preparations must be
followed by acid etching for reliable bonding to resin composite
May weaken the irradiated surface (lower microhardness) Defocusing effect due to water spray Tissues can be only removed when it is
visible to operator’s line of sight. Lack of tactile sensation Large devices
Waterlase MD Biolase ezlase 940
Future Development
New more efficient generations of erbium lasers.
Lasers with femtosecond pulse duration (pulse duration = 10-15 s)
Air Abrasion (Kinetic Cavity Preparation)
This technique uses a pressurized stream of small aluminum oxide particles to abrade carious lesion.
Typical Air Abrasion system: - Particle diameter 27-50 µm. - Powder flow rate 0.7-4.2 g/min - Air pressure 40-160 psi - Operating distance from tooth 0.5-2 mm
Air abrasion Handpiece
Air Abrasion Unit
Clinical Indications
Removal of superficial enamel defects For detection pit and fissure caries by removal of
organic debris. Removal of enamel surface stains. Removal of localized minimal carious lesion Surface preparation of abfractions and abrasions
to brake the glaze of the surface for better bonding.
Removal of existing restorations. The need for anesthesia may be avoided
because of the cooling effect of the high pressure air
Cavity prepared using air abrasion technique
Advantages of Air Abrasion
Less painful than bur preparation due to less noise and vibration.
More conservative than bur for minimal fissure and pit caries.
Roughened surfaces may favor better bonding….However air abrasion is not a substitute for acid etching
Limitations of Air Abrasion
There is little tactile sensation Unable to remove gross caries. Removes normal and relatively hard dentin. Remove exposed cementum and root
dentin. Splattering f powder-risk of ingestion. Unable to prepare well-defined cavity
margins. Does not obviate the need for acid etching. May lacerate soft tissues Removal of large amalgam causes release
of mercury Mandatory need for rubber dam, high
velocity evacuation and protective eyewear
Future Developments in Air Abrasion
Less abrasive powders - Softer particles may be more effective in selective removal of carious dentine
Polymer Bur Described by Boston (2000). Made of a softer polyamide/imide polymer
material. Remove infected dentine only Manufacturer: SmartPrep (SS White, USA) Harder than carious dentine and softer than
healthy dentine Designed for single use on slow-handpiece Remove caries from central of lesion to
periphery Less effective than carbide bur in caries
removal (Dammaschke et al, 2006)
Polymer burs SmartPrep before (1a) and after (1b) use (Dammaschke et al, 2006)
Micropreparation Burs Fissurotomy Burs (SS White,USA) allow
exploration of the fissures with minimal removal of enamel.
It is 1.5-2.5 mm in length and tapers to fine carbide tip.
Other burs such as Brassler 889M-007 bur and Microdiamond 838M-007 burs are used for minimal preparation.
Microinstruments (Micropreparation set) requires low contact pressure (< 2N)
Fissurotomy Bur
Conventional bur versus fissurotomy bur
Photoactivated Disinfection The system use disinfectant solution
applied to deep caries, allowed to penetrate softened dentin for 60 s, and then photoactivated with low-powered diode laser for 1 min.
Dilute toluidine blue binds to bacteria. Red light activation release oxygen that kills the cells
Healthy tissues are not damaged by the laser
Toluidine blue is safe at the used dilution
Toludine blue and laser acts together effectively.
Photo-Activated Disinfection (PAD)
Carisolv Gel Carisolv s a chemomechanical method
for caries removal. It is a mixture of amino acids and 05%
sodium bicarbonate The resultant high-pH chloramines
reacts with denatured collagen in carious dentin
Softened dentin is removed with special hand instruments
Special hand instruments used with Carisolv Gel
Clinical Indications For Carisolv Gel
Removal of root and coronal caries where access is easily obtained
Due to selective removal of carious dentine, the need foe anesthesia is reduced , thus the technique is indicated in children, dental-phobic patients and special needs patients
Advantages of Carisolve Gel Selective removal of carious dentine. The reduced need for anesthesia Does not affect the bonding to
composite. Removes smear layer Does not cause adverse effect on the
pulp.
Disadvantages of Carisolv Gel
Technique requires longer time than conventional method.
May be inefficient for removing caries at enamel-dentin junction.
Caries under overhanging enamel may go unnoticed.
Large lesions needs to be accessed using rotary bur.
LِAtraumatic Restorative Treatment (ART
Atraumatic Restorative Treatment is a procedure based on removing carious tooth tissue sing hand instruments alone and restoring the cavity with an adhesive restorative material namely glass ionomer
Hand instruments used in ART
Reasons for using hand instruments in ART
Makes restorative procedure accessible to all population.
Minimal cavity preparation Low cost Reduce need for anesthesia Simplified infection control due to
easy cleaning and sterilization
Reason for using glass-ionomer in ART
Glass ionomer sticks chemically to enamel and dentin
Fluoride release Compatible to oral and hard dental
tissues
Advantages of ART
Benefit the less-industrialized and deprived communities
Minimal invasion preparations Friendly procedure for children,
fearful adults, physically or mentally handicapped, people living in nursing homes and the home-bound elderly
Disadvantages of ART
Restorations tend to fail and wear. Incomplete removal of bacteria Wear and failure means that
patients require frequent review by trained personnel
Difficult o remove caries in inaccessible lesions.
Caries Detection Dyes Dyes such as 1.0% acid red in propylene
glycol. They stain infected dentine and organic
matrix of demineralised of carious dentin that should not be removed.
They stain dentin naturally with low minerals such as circumpulpal dentin and enamel-dentin junction
Result in overpreparations. Not useful in detecting pt and fissure caries
because they stain food debris and other organic materials in the fissure
They are not recommended
Caries detecting dyes stains demineralised matrix of carious dentin that should not be removed