Protapers are a modern version of nickel-titanium instruments that are actively used during root canal preparation. They are ultra-flexible, so they work in hard-to-reach areas for traditional tooling. Consider the structural features of manual protapers, their advantages and disadvantages, as well as the application procedure.
Benefits of working with universal protapers
Protapers are made from a special alloy that is 56% nickel and 44% titanium. They have the same design as the machine versions, but are used in more complex clinical situations. Due to its ultra-flexibility, high safety and cutting efficiency, it is widely used by dentists in clinics.
Benefits of manual protapers:
Easy to use
Color coding makes it easy to match the sequence of instruments regardless of the shape of the root canal. Drying agents andobturations have the same color range.
Speed
Only three tools are needed for the job, which have high cutting efficiency.
High performance
Root canal preparation and removal of dentinal chips are of high quality due to the increased taper of the apical part.
Safety
The probability of deviating from the canal passage is minimal due to the rounded guide tip.
Most dentists prefer the manual option due to better tactile control when performing complex manipulations from an anatomical point of view.
Working with manual protapers: classification
Dental protepers for endoscopic treatment are used strictly according to the instructions. Each set contains six tools that can be divided into two groups: shaping and finishing files.
Shaping files are designed to shape the root canal.
Varieties of forming files:
- SX - are used to work with short root canals or to give the necessary shape to the coronal part of long passages (the length of the protaper is 19 mm, the diameter at the tip of the working part is 0.19 mm, the circumference of the base is 1.20 mm).
- S1 - used for preparation of the upper third of the root canal (the size of the manual protaper can be 21 or 25 mm, the diameter at the tip is 0.17 mm, the taper increases along the entire length of the workingparts from 0.02mm to 0.11mm).
- S2 - equal in length to the previous version, but designed for preparation of the middle third of the root canal (circumference at the tip - 0.2 mm, taper increases gradually from 0.04 mm to 0.115 mm).
Finishing files are used at the final stage to shape the apical third, align and widen the middle third of the canals. They are divided into the following categories: F1, F2 and F3. All have a fixed taper, are flexible enough, but differ in length. Size F1 is 0.2mm, F2 is 0.25mm and F3 is 0.3mm.
It is possible to use auxiliary shaping files (shapers), which are used to give the optimal shape to short channels, to access long passes or to define a directional channel.
Marking hand tools
Manual ProTaper is used for the same manipulations as the machine, but in more complex cases. At the same time, the marking on the products is the same. The standard set consists of six tools, which are distinguished by the color of the handle depending on the technical data.
Standard labeling of assorted manual protaper handles:
- Sx - orange;
- S1 - purple;
- S2 - white;
- F1 - yellow;
- F2 - red;
- F3 - blue.
Thanks to these notations, it is convenient to use hand tools in the required order. There are also F4 (with a black handle) and F5 (with a black and yellow handle), the length of the active area of which is 22 mm. They aredesigned for initial or final processing of root canals.
Design Features
Knowing the features of work and the order of manual protapers, it is worth noting their design characteristics. It is thanks to them that the work of the dentist in hard-to-reach places is greatly facilitated.
The design feature that provides the benefits of operation is as follows:
Multi-step taper
Improves flexibility, efficiency in cutting, so there is no need to re-pass through the canal. For example, an Sx file in D1-D9 has a progressive taper of 3.5% to 9% and a fixed taper of 2% in D10-D14. Also, nine values \u200b\u200bhave file S2, and S1 - 12.
Trihedral convex cross section
Thanks to this, the main rod is strengthened, and the tool itself becomes super flexible. It also greatly increases safety, as the torsion load is reduced, and the likelihood of contact between the walls of the channel and the tool blade is minimal.
Spiral steps and angles change
The helix and pitch angle is constantly changing, making it easier and more efficient to remove waste material.
The diameter of the tip differs depending on the file
Files, both finishing and shaping, have different diameters for safe and efficient advancement deep into the canal.
Guide tip modified
Due to the shape of the tip, the use of the tool is notleads to damage to the walls of the channel, penetrating through soft tissues.
Short handles
Handle sizes up to 12.5mm for better access to posterior teeth.
Set of six tools
Allows to prepare canals of any complexity, making manual instruments universal.
Indications and contraindications for use
The work of manual protapers according to the method is so delicate and filigree that devices are used only in a medical institution by specialists who have undergone special training. The instruments are designed for shaping and cleaning root canals. Thanks to their super-flexibility, the channel is easier to clean.
Their introduction is carried out by light pressure, which ensures the patency of the zone. But at the same time, it is necessary to observe the speed limit within 500-700 rpm. There are no contraindications to the use of hand tools.
Disadvantages of working with protapers
While there are many benefits to working with, manual protapers also have disadvantages.
Cons include:
- impossibility to process wide canals (more than 30 sizes) because there is no tool with a large apical diameter;
- the maximum length of the canal that can be processed reaches 31 mm;
- mechanism to prevent obturation is not provided, a layer of lubricant may remain on the canal walls, which will subsequently prevent medicines from entering the canal.
Measuresprecautions
There are certain rules to follow when using hand tools.
Precautions are as follows:
- many instruments are marked "single use" (sterilization and disinfection multiple times increase the risk of file fracture);
- protapers are not immersed in sodium hypochlorite solution, the concentration of which exceeds 5%;
- cleaning is carried out strictly according to the instructions;
- use manual protapers at a constant speed between 150-350rpm;
- the file is checked for possible deformation, the grooves should be cleaned as often as possible;
- to create straight channel access, it is worth using shaping files with separate sweeping movements;
- Sweeping motions are not applied to finishing files;
- when using finishing files for the full working length, it is worth removing the tool immediately.
Mechanical root canal treatment technique
Processing canals with manual instruments is carried out in different ways, which directly affects the use of manual protapers in order.
Varieties of processing techniques:
Standard
Manual endotonic instruments are used starting from the smallest size. As you move along the canal, larger and larger diameter protapers are used, reaching all the lengths of the passage. Processing takes place in one large K-file. After he is completelyinserted into the canal, the instrument is rotated 90 degrees clockwise in depth.
Reverse rotation occurs with a slight counterclockwise pressure of 270 degrees. This is followed by another turn in the opposite direction by 180 degrees. After that, the instrument is removed from the mouth, treated with medicines and re-introduced into the canal for the entire length.
Step-back
First, the root canal must be expanded to the apical foramen, after which the K-file is inserted one size larger, but 1 mm less than the working length. After that, the tool is changed, in which the working length gradually changes (by 2, 3 mm, and so on). With the help of H-files, the surface of the root is smoothed, and thus its taper is formed.
Crown-down
Formation of the orifice middle part and access to the apical third of the canal is carried out after the expansion of the orifice. Next, the working length and tooling are determined. The canal walls are aligned in the final part.
General recommendations
According to the methodology, manual protapers are disinfected, cleaned and sterilized before use (18 minutes by autoclave and at a temperature of 134 degrees, pressure no more than 3 bar).
General provisions include the following:
- Disposable instruments are not reusable.
- The doctor who uses the instrument is responsible for the sterility of the product.
- To avoid contamination, it is worth using personal productsprotection (goggles and gloves).
- Disinfectant solutions must be of high quality.
- Hydrogen peroxide destroys tungsten carbide burs, nickel-titanium tools and plastic stands.
- Do not use caustic soda, alkali and mercury s alts.
- The maximum number of processing hand tools is limited to five. After that, they begin to break down.
Conclusion
Manual protapers, according to dentists, are much easier to use than machine ones. They are convenient and help in difficult situations with non-standard anatomical features of the root canal. At the same time, it is worth using such tools strictly according to the instructions. It includes not only the rules of use, but also precautions. In general, a hand tool has many more advantages, so it is often used.
