U2 - Universal Curettes & Calculus Removal

What is the patient-safety rule for transferring or handling instruments?

Never flip instruments over the patient's face.

Where should instruments be held to avoid injury if dropped?

Over the patient's chest or completely to the side.

Why should an instrument never be flipped over a patient's face?

A slip or dropped instrument could injure the patient.

What is the ideal working angulation for calculus removal?

60-80° between the cutting edge/face and tooth surface.

What can happen with angulation greater than 90°?

Tissue damage to the patient.

What can happen with angulation less than 45°?

Burnished calculus that is very difficult to remove.

What is burnished calculus?

Calculus made smooth or flattened against the tooth rather than effectively removed.

How should large calculus deposits be removed?

In sections, using a series of short, firm instrumentation strokes.

Should large calculus deposits be removed one outer layer at a time?

No. Completely remove one section before moving to the next.

What is the correct order for removing calculus across sections?

Completely remove calculus from the first section, then move to the next section.

What pressure is used for assessment/exploratory strokes?

Little to no lateral pressure.

What pressure and stroke length are used for scaling?

Short, controlled strokes with firm lateral pressure.

What pressure and stroke length are used for root debridement?

Moderate pressure against the root surface; longer strokes than calculus removal.

How do exploratory and scaling strokes differ?

Exploratory strokes use little/no lateral pressure; scaling strokes use short, controlled, firm lateral pressure.

How do scaling and root-debridement strokes differ?

Scaling uses short, firm strokes; root debridement uses longer strokes with moderate pressure.

What three steps follow positioning of the dominant hand for instrumentation?

Grasp; establish fulcrum, insertion, adaptation, and angulation; then activate.

What is the first action in the overall sequence for establishing position?

Assume the clock position for the treatment area.

What is the next positioning step after selecting clock position?

Establish patient chair and head position.

What equipment adjustments precede instrumentation?

Adjust unit light, self-check clinician/patient/equipment positions.

What does the nondominant hand do during setup?

Places fingertips as shown for the selected clock position.

What does the dominant hand do during setup?

Places fingertips as shown for the selected clock position.

What supports the weight of the hand during calculus removal?

A straight fulcrum finger.

Where does the fulcrum finger press to help generate force?

Down against the occlusal or incisal surface.

Which fingers apply inward pressure against the instrument handle?

Index finger and thumb.

What are the three components of force preparation?

Straight supporting fulcrum; downward fulcrum pressure; index finger/thumb inward handle pressure.

What four stroke directions are listed in the lecture?

Vertical, horizontal, oblique, and multidirectional.

Which stroke direction is illustrated for anterior teeth?

Vertical.

Which stroke direction is illustrated for facial and lingual surfaces?

Oblique.

Which stroke direction is noted as useful for patients with lingual bars?

Horizontal.

Which stroke approach is associated with root planing?

Multidirectional strokes.

In supragingival calculus removal, where is the working end positioned first?

Just apical to the calculus deposit.

What does "lock the toe-third and open the face" mean in supragingival scaling?

Lock the toe-third against enamel, apply inward pressure with index finger/thumb, and establish correct working angulation.

In what direction is the supragingival scaling stroke activated?

Away from the gingival tissue.

What should stay locked against enamel during supragingival activation?

The toe-third of the working end.

What should happen between calculus-removal strokes?

Pause briefly, relax the fingers, and reposition using a relaxed grasp.

Why must clinicians rely on tactile sensation for subgingival calculus removal?

The calculus is beneath the gingival margin and cannot be seen directly.

What is subgingival insertion?

Gently sliding an instrument's working end beneath the gingival margin into the sulcus or pocket.

What angulation is used for subgingival insertion?

A closed angle, as close to 0° as possible (the slide illustrates an insertion range of about 0-40°).

Why is the angle closed for subgingival insertion?

To allow gentle insertion beneath the gingival margin before opening to working angulation.

Where should the blade be positioned relative to subgingival calculus before scaling?

Apical to the calculus deposit.

After reaching the base of the sulcus/pocket, what is the next step?

Open the blade to establish working angulation.

Where does posterior subgingival insertion begin?

At the distal line angle.

Where does anterior subgingival insertion begin?

Overlapping the midline.

What is the complete subgingival insertion sequence?

Begin at distal line angle posteriorly or overlap midline anteriorly; close angle near 0°; slide to base of sulcus/pocket apical to deposit; open to working angulation.

What are the two major instrument categories for calculus removal?

Sickle scalers and curettes.

What are the two types of curettes named in the slides?

Universal curettes and Gracey curettes.

What is adaptation?

Placing the first 1-2 mm of the working end's lateral surface (side of tip) in contact with the tooth.

How much of the working end should be adapted to the tooth?

The terminal 1-2 mm.

What part of a sickle scaler is used for adaptation?

The first 1-2 mm of the lateral surface near the tip.

What anatomical feature distinguishes the tip of a sickle scaler from a curette?

A sickle has a pointed tip; a curette has a rounded toe.

Why is correct working-end selection important on posterior teeth?

It permits proper adaptation and angulation against the tooth.

What does the posterior sickle-scaler sequence require when changing surfaces?

Redirect the instrument for the next surface.

What is a universal curette?

A curette designed for instrumentation on any tooth surface, using either cutting edge.

What is the toe shape of a universal curette?

Rounded.

What is the cross-sectional shape of a universal curette?

Semicircular.

How many cutting edges does each universal curette working end have?

Two.

How is the universal curette face oriented relative to its lower shank?

Perpendicular.

What angle does the universal curette blade form with the terminal shank?

90°.

Are both cutting edges of a universal curette usable?

Yes, both cutting edges are used.

Can universal curettes be used on any tooth surface?

Yes.

What distinguishes a universal curette from a sickle scaler at the working end?

The universal curette has a rounded toe; the sickle scaler has a pointed tip.

Which part of a posterior universal curette is adapted?

The terminal 1-2 mm of the working end/cutting edge.

What are the three regions labeled on the posterior curette working-end diagram?

Upper 1/3, middle 1/3, and lower 1/3.

What is the starting grasp when placing a universal curette apical to calculus?

A light exploring grasp.

What is the first activation step for a universal curette?

With a light exploring grasp, place the cutting edge apical to the deposit.

What follows positioning the curette apical to a deposit?

Set the fulcrum and tighten the grasp.

How is lateral pressure applied with a universal curette?

Pull the instrument toward the tooth using appropriate lateral pressure.

In what direction is the universal curette pulled during activation?

Coronally.

What motion activates the universal curette scaling stroke?

Wrist/forearm motion.

When should universal curette strokes be repeated?

Until the surface feels smooth.

What is the complete universal curette activation sequence?

Light exploring grasp and position apical to deposit; set fulcrum/tighten grasp; apply lateral pressure toward tooth; pull coronally with wrist/forearm motion; repeat until smooth.

What is the first step in posterior universal curette application?

Establish a fulcrum.

How is the correct posterior universal curette working end checked?

The terminal shank is parallel to the tooth surface; the slide labels this V → D.

Where is the posterior universal curette first inserted?

At the distal line angle.

Which stroke is used into the posterior distal col?

A vertical stroke.

After scaling the posterior distal area, what is done to the working end?

Remove it and redirect the face/toe toward the mesial.

Which stroke is used across the posterior facial or lingual surface toward the mesial col?

An oblique stroke.

What is the posterior universal curette sequence?

Establish fulcrum and working end; insert at distal line angle; stroke vertically into distal col; remove/redirect toe toward mesial; reinsert and stroke obliquely across facial/lingual into mesial col.

What does the posterior application diagram emphasize?

Different working ends and cutting edges are selected to adapt to different posterior surfaces.

What is the first step in anterior universal curette application?

Establish a fulcrum for the sextant.

How should the terminal shank be oriented for the correct anterior working end?

Oblique to the long axis of the tooth.

Where should anterior curette strokes begin?

Overlapping the midline.

What stroke is used from the anterior midline toward the line angle?

An oblique stroke.

What stroke is used into the anterior col?

A vertical stroke.

Which anterior surfaces are scaled first?

All near surfaces, facial and lingual.

What chair-position change is described before scaling anterior far surfaces?

Change the chair/clinician position to the back.

Which anterior surfaces are scaled after near surfaces?

All far surfaces, facial and lingual.

What exception is noted for maxillary anterior instrumentation?

The clinician can remain at the 12 o'clock position.

What is the complete anterior universal curette sequence?

Establish fulcrum and correct working end; overlap midline; stroke obliquely to line angle and vertically into col; scale near facial/lingual surfaces; change position to back; scale far facial/lingual surfaces.

What visual cue helps confirm the correct anterior curette working end?

The terminal shank should be oblique to the long axis of the tooth.

What does seeing more of the instrument face indicate in the anterior comparison images?

The slide labels that as the incorrect working end.

What does seeing less of the instrument face indicate in the anterior comparison images?

The slide labels that as the correct working end.

Why roll the handle during anterior instrumentation?

To maintain adaptation as the working end follows the tooth contour.

What is the purpose of positioning the instrument under the contact area?

To access and instrument the proximal surface beneath the contact.

What areas can universal curettes scale?

Both supragingival and subgingival areas.

What is the primary calculus-removal role of universal curettes in this lecture?

Remove as much calculus as possible during supragingival and subgingival scaling.

Which instruments follow universal curettes for fine scaling and root planing?

Area-specific curettes.

Which area-specific curettes are named as the next lecture topic?

Gracey curettes.

Which instruments are assigned for posterior practice in the lecture schedule?

204S and Barnhardt 5/6.

Which instrument is assigned for both posterior and anterior practice?

Barnhardt 5/6.