CVD DIAMOND BURS 2

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MANUFACTURING

These tips, called CVD, are produced in a reactor in which a mixture of methane and hydrogen gases results in the formation of a single artificial diamond layer without space between the grains on the substrate (a molybdenum rod)

WORKING PRINCIPLE

CVD diamonds burs present unidirectional oscillating movement with maximal displacement ranging from 50 to 60 micron,at oscillating frequencies ranging from 25,000 to 32,000 Hz.

CVD diamond tip require only a slight touch to promote tooth grinding

This differs from the high speed handpiece, which is manipulated with pendulum movements over tooth structure.

Movement with maximal displacement ranging from 50 to 60 micron,at oscillating frequencies ranging from 25,000 to 32,000 Hz.


CVD diamond burs must be handled with light hand pressure,just enough to guide the instrument.

If too much load pressure is applied,the cutting effectiveness is reduced and pain,noise,and heat will be generated.

A greater application force reduces the cutting ability of the tip and may lead to fracture of the molybdenum substrate.

In addition the lack of irrigation of the ultrasound instrument on the treated surface may cause the tip to heat up and fracture.

This system doesn’t lose superficial diamond during cutting,subsequently extending the lifetime.

CVD feature significantly decrease the risk of metal contamination

CVD instrument allows the capability of working at high inclination angles,resulting in safer proximal finishing with less chance of hitting adjacent tooth.

CHEMICAL VAPOUR DEPOSITION(CVD) DIAMOND BURS

CHEMICAL VAPOUR DEPOSITION(CVD) DIAMOND BURS

CVD technology allows high adherence of the diamond as a unique stone on the metallic surface with excellent abrading performance.

CVD diamond burs become an option for cavity preparation,and preservation of tooth structure.

In 1996,CVD diamond burs coupled with an ultrasonic handpiece were introduced in dentistry to eliminate problems relate with diamond burs

CVD method produce high adherence between the diamond film and metal surface,induced by chemical bond

Because of the inherent roughness of the sharp edged and polycrystalline diamond layers,these tools are well suited for tooth grinding










They are obtained by chemical vapour deposition( CVD) of diamond film over a molybdenum substrate.

They were synthesized inside an enhanced hot filament assisted reactor.

This manufacturing process,and the adaptation to an ultrasonic handpiece,provide some potential advantage.

SMART BUR 2

PROCEDURE









WITHOUT LA

SMART BUR Cutting is limited to the superficial layer of affected dentin will not remove the odontoblast reaction zone of mineralized tubule plugs and can be completed without the use of LA

When working with the polymer(SMART) bur, and early intensive contact with hard areas of the tooth should be avoided to reduce the possibility that the excavating performance of the bur is diminished.

Like conventional bur,polymer(SMART) bur rake angle is also negative.unlike cabide bur,the downward pressure applied by the polymer bur against the tissue is dessipated as the bur starts abrade when it encounters hard dentine

The dentist was requested to exert as little force as possible on the SMART BUR.

CONSERVATIVE

One of the goals of conservative dentistry is to develop a method of removing caries-infected dentin while preserving caries-affected dentin.

The polymer(SMART BUR) instrument appears to offer a
straightforward and efficient means of achieving this goal and conserving healthy tooth

SMARTPREP (SMART BUR) INSTRUMENTS

POLYMER BUR or SMART BUR

The SMARTPREP Instrument is a medical grade polymer that safely and effectively remove decayed dentin, leaving healthy dentin intact.

The hardness of instrument is less than that of healthy dentin and enamel but harder than carious dentin

SELFLIMITING

The polymer instrument is self-limiting and will not cut sound dentin unless applied with great force, and then it will only wear away, rather than cut, the healthy dentin

Smartprep instrument in a range of sizes (equivalent to round burs nos. 2, 4 and 6)

The Smartprep Instrument is used in a slow speed handpiece (500-800 rpm) to complete caries removal

They are single-patient-use rotary instruments

Carious tissue is removed with circular movements starting from the centre to the periphery.

ADVANTAGE

They are being used for deep caries removal in anticipation of an indirect pulp capping procedure

Use the Smart-Prep burs in the beginning of their clinic experience and hopefully a

void iatrogenic pulp exposures

DISADVANTAGE

Polymer bur left large amount of decayed tissue unexcavated (underprepation)

Technique sensitive (the Smart Prep can be readily defeated by the dumb operator)

the burs disintegrate when they touch enamel or even sound dentin

potentially expensive

BURNISHERS

BURNISHERS

To burnish amalgam restoration.
for making occlusal anatomy of composite restoration
for marginal adaptation of gold

TYPES

• PK Thomas no. 3(cone) burnisher
• Beavertail burnisher no. 2
• Foot ball or ovoid no.30 burnisher
• Sprateley burnisher
• Anatomic burnisher

ANATOMIC BURNISHER
They are used for sculpturing occlusal anatomy in posterior resin composite restoration prior to polymerisation.

BEAVERTAIL
Closing of marginal gap between gold and tooth in cast gold restoration



SPRATELEY
For burnishing proximal gingival margin metallic restoration