Isolation and retraction instruments
For high-quality defect restoration, it is necessary to reliably isolate the operating field. This is facilitated by matrices, which are broadly divided into contour and strip matrices.
- Contour matrices (available in metal, polymer, and composite versions) give the restoration the correct anatomical shape and significantly save the volume of material that will have to be ground down later.
- Strip matrices serve to delineate the contact points of adjacent teeth.
- Cervical matrices (aluminum or transparent plastic) are indispensable in the cervical area: they create the necessary compression, protect against gingival fluid and micro-air bubbles.
Matrix bands are fixed with special keys (as in the SuperMat system), universal holders, or work as self-fixing systems (with an adhesive layer or stopper).
To tightly adapt matrices in the gingival area, retention wedges are used. Light-transmitting plastic wedges are ideal for light-cured composites, as they diffuse light into the interdental spaces. To open the gingival sulcus, retraction cords are used, which are gently inserted under the gum using a paddle-shaped instrument with a beveled shank — a cord packer.
Instruments for preparation and material placement
Before placement, the material must be mixed. Binary masses (cements, chemically cured composites) are prepared using therapeutic spatulas. To prevent abrasive cement powder from scratching the metal and steel particles from discoloring the filling, clinicians often choose spatulas made of plastic, agate, or bone. Orthopedic masses (plaster, alginates) are mixed with larger metal or plastic spatulas.
The placement of medicinal substances, liners, and composites is carried out using burnishers. This is a basic instrument whose configuration depends on the clinical situation:
- Single-angle burnishers — for cavities accessible to direct vision.
- Double-angle and offset-plane burnishers — for working in proximal areas.
Working with toxic amalgam is subject to strict rules: the mass is prepared in capsule or automatic amalgamators and delivered to the cavity using plunger or lever amalgam syringes, which ensure precise dosing.
Condensers: condensation and packing
After placement, the mass must be compacted. This task is performed by condensers — instruments for pressing the material against the defect walls.
Depending on the task, the shape of the working part is selected:
- Spherical and cylindrical (rounded) — for composite condensation.
- Planators (reverse-conical, flat) — for incremental packing and creating a smooth surface.
- With a mesh or scalloped surface — strictly for amalgam packing.
For distal contact areas, triple-angle return-action condensers are used (tilt angle up to 110°). Of particular note are micropackers — small-sized cylindrical condensers whose diameter is selected according to the root canal size for its retrograde filling. To save time during the appointment, double-ended models are often used (e.g., the double-ended Bennett condenser).
Carvers, burnishers, and finishing
Contouring of the relief prior to polymerization is performed with carvers and burnishers.
- Carvers are cutting instruments that trim micro-volumes of excess with thin edges. For proximal surfaces, Gurtysen, Wieland, Hollenback, or Nystrom models are used. For restoring occlusal cusps and fissures — Vignon, Mac经常, or the double-ended "cleoid-discoid" instruments.
- Burnishers (conical and disk-shaped) are used to smooth fissure-cusp transitions with sliding movements.
At the final stage, after the filling has set, finishing knives (used to remove hard residues of adhesive and composite) and strips are used. Strips are abrasive strips 2–6 mm wide on a plastic or metal base. They smooth out irregularities on contact surfaces that the bur cannot reach. Strips are tensioned manually or using a special frame strip holder.
Briefly: answers to topical questions
What instruments are used for the finishing and polishing of composite restorations?
For the finishing and polishing of composite restorations, burnishers, polishing systems, abrasive points, and polishing brushes are used.
- Burnishers — are used for finishing strictly before the polymerization phase of the material begins.
- Polishing systems and discs — are used for grinding and polishing the finished filling.
- Sandstone abrasive points — are designed for grinding composites.
- Polishing brushes — are used for final polishing (available as nylon brushes and metal wire brushes).
Which manual endodontic instruments are used for pulp extirpation?
For the extirpation (removal) of the root pulp, pulp extractors, root rasps, and reamers are used.
- Pulp extractor (Barbed broach) — an instrument with spirally arranged pointed barbs, providing secure gripping and simultaneous evacuation of soft tissues when rotated around its axis.
- Root rasp — an instrument with teeth, visually resembling a pulp extractor, designed for the removal of soft tissues.
- Reamer (Reamer) — used for cutting the root pulp, resulting in a clean-cut wound.
How does a K-file differ from an H-file during root canal instrumentation?
The main differences lie in the manufacturing method, the shape of the working part, and the mechanics of movement during canal preparation.
| Characteristic | K-file (K-File) | H-file (Hedstrom-File) |
|---|---|---|
| Manufacturing method | Twisting a tapered blank | Milling (machining) from a blank |
| Structure of the working part | Has 1/4 to 1/2 turns per 1 mm | A series of cones with increasing diameter, cutting edges at a right angle |
| Working movements | Push-pull (reciprocating) | Pulling strokes (rotation is strictly prohibited) |
What manual instruments are used for lateral condensation of gutta-percha points?
For the lateral condensation of gutta-percha points, spreaders are used.
- Spreader (spreader) — a hand or finger endodontic instrument with a smooth, pointed working part. It is designed for lateral compaction of the filling material using the cold lateral compaction method. During the procedure, the instrument pushes the main gutta-percha point against the lateral wall of the root canal, freeing space for the insertion of auxiliary points. The color of the spreader handle corresponds to the size of the gutta-percha point according to the ISO standard.
What ISO color coding is used for manual endodontic instruments?
According to the standard color coding for endodontic instruments:
- Pink — 006
- Grey — 008
- Purple — 010
- White — 015, 045, 090
- Yellow — 020, 050, 100
- Red — 025, 055, 110
- Blue — 030, 060, 120
- Green — 035, 070, 130
- Black — 040, 080, 140
This system is used for reamers, K-files, flexible files, Hedstrom files, and lentulo spirals. Specific color-coding systems are used for barbed broaches and rat-tail files.
Difference in design: Carver — from the word "carve", it features sharp edges and cuts away material. Burnisher — does not cut, but gently "smooths" the surface prior to its polymerization.
Class and exam questions
Why is it better to avoid metal spatulas when mixing cement?
Cement powder has abrasive properties. When rubbing against metal, it can scrape off microparticles of steel, leading to their ingress into the material and unwanted discoloration of the restoration.
What instruments are needed for retrograde root canal filling?
Micro-packers are used for this purpose — specialized small-sized cylindrical pluggers whose diameter strictly corresponds to the diameter of the instrumented canal.
What else to study on this topic
- Clinical indications for the use of various types of matrix systems (Super Mat, self-retaining)
- Specifics of working with amalgam: from capsule mixing to packing
- Techniques for atraumatic gingival retraction using cord packers
- Differences in the technique of using carvers for anterior and posterior teeth
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Other topics in «Chapter 3. Dental Instruments»
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