DTHY 370: Powered instruments

- utilize air turbine as energy source

- convert air pressure -> high freq. sound waves -> produce vibrations ofpwoered working end

- low frequency: 3,000-8,000 cycles per second

sonic scalers

- convert electrical energy tp high freq sound waves which makes rapid vibrations

- higher freq: 18,000-50,000

ultrasonic scalers

piezo: uses electrical energy to activate crystals in handpiece to make vibrations on working end

magnetostrictive: transfer electrical energy to metal stacks or ferrous rod to produce vibrations of working end

piezoelectric vs magnetostrictive

- sonic was invented in the 50's

- in 60's and 70's it was used only for heavy supra calc

- late 80's: slim ends, but doesnt work with all powered devices

- today: many tip designs, as effective as hand instruments

history of powered instuments

vibration of working end causes microfractures which makes deposit removal

modes of action: mechanical action

- formation of tiny bubbles when water stream contacts vibrating working end

- bubbles collapse which makes shock waves and destroys bacterial cell walls

modes of action: cavitation

- generated by ultrasound in presence of fluid environment

- has potential to destroy or disrupt bacteria

modes of action: acoustic microstreaming

therapeutic washing of sulcus and root surface to remove endotoxins and loose debris

fluid lavage

- water is used as a coolant

- chlorhexidine gluconate can provide pocket reduction

water line/reservoir for powered instruments

low water volume= increased tip heat and warmer water, for pt with cold sensitivity

high water volume= less heating of tip and cold water

water volume vs temp of water

- speed of movement

- number of cycles per second

frequency

- distance of tip displacement during one cycle

- determined by power settings: high power= long, forceful stroke

low power= short, less forceful stroke

amplitude

lowest, for client comfort and tip design

what power setting do we always start with

- frequency+amplitude

- low freq+low amp-> deplaquing

- high freq+high amp -> tenacious calc

cleaning efficiency

- increased efficiency

- multiple surfaces of tip are used

- conserves cementum - less change for stress injuries

- irrigation

- less distention

- no need to sharpen

advantages of powered instruments

- client comfort (water spray)

- decreased tactile sensation

- noise issues

- infection control

- aerosol production

- reduced visibility

- precautions and limitations

- damage to restorations

disadvantages of powered instruments

- light and heavy deposits/biofilm

- perio surgeries

- removal of excess cement/bonding

indications for powered instrumentation

- children: heat damage of large pulp chambers

- avoid use on restorations, demin, dentinal hypersensitivity

- communicable diseases: hepatitis, tb, strep

- immunosuppression: HIV, chemo

- cardiac pacemakers: ultrasonics can interfere

precautions for powered instruments

- unstable pulmonary disease: reschedule elective care

- dysphagia: muscular dystrophy, paralysis

contraindications for powered instruments

position: same positions, sit in supine and tilt head to side

grasp: modified pen grasp, lateral pressure with no fulcrum pressure

finger rest: intra or extraoral, cross arch, opposite arch

position, grasp, and finger rest for powered instruments

- use lateral and back of instrument, never the tip

- term 2-3mm of tip on tooth

- work from top to bottom when removing a deposit

adaptation of powered instruments

tip motion: compressed air drives tip in elliptical pattern, all surfaces are active

frequency: 3,000-8,000, lower freq

amplitude: less range than ultrasonic

power setting: pre determined, adjust water only

sonic scaler: tip motion, freq, amp, power setting

tip motion: tip moves in linear pattern, forward and backward with lateral tip only

freq: 25,000-50,000 cps

amp: green tip- up to 20%, blue tip- up to 70%

piezoelectric: tip motion, freq, amplitude

P: supra and sub

A: supra only

PS: thinnest, for sub and supra

piezo tips

diamond coated or plastic coated for implants

coating of piezo tips

- adapt only term 2-3mm to tooth

- used curved inserts for root surfaces

improper adaptation of powered instruments

stroke: move tip slowly

coverage: use overlapping strokes to cover entire surface

tip pressure: hold tip w light, secure, grip and avoid heavy lateral pressire

powered instruments: stroke, coverage, tip pressure

metal stack: converts electrical power into vibrations

o-ring: seal that keeps water flowing to tip of insert

handle grip: portion of insert grasped by clinical

interchangeable inserts of magneto

tip motion: moves in elliptical pattern and all sides are active

25 kHz unit: 25,000 cps and shorter amp

30 kHz unit: 30,000 cps and longer amp

magneto: tip motion, kHz units available

standard: supra and sub

thin: supra and sub

ultra thin: perio debridement

magneto insert diameter

implant inserts: must have plastic tip

diamond coated: used for furcation and root planing

inserts: .8mm ball on end

magneto insert design

blue: heavy supra

green: supra and sub

2nd one is for anteriors

last 2 are right and left

what are each of these used for

orange: heavy supra

navy/purple: sub or supra

green and red: posterior right and left

what are each of these used for

all the same as the other blue and green ones, but they are newer and have bigger ergonomics

what are each of these for

- rinse w water and dry prior to autoclaving

- don't put in sonic cleaner

- replace o rings when needed

- watch for worn inserts and replace after 2mm loss

magneto insert care & maintenance