Basics of infection control and ergonomics
Safe work with surgical instruments begins with proper spatial arrangement. Professor Shan is considered the "father" of European dental ergonomics, having developed the principles of "four-handed" dentistry (dentist and assistant).
Optimization of the treatment process allows to:
- Reduce the burden on the patient and staff.
- Increase the volume of procedures performed in a single visit.
- Prevent the development of occupational diseases and fatigue.
Since the oral cavity is considered an initially infected environment, the use of personal protective equipment (PPE) is strictly mandatory. The minimum list includes a medical gown, gloves, mask, and protective goggles (or face shield). To prevent infection of the office itself, vacuum equipment is used — aspiration systems that remove fluid and dust particles from the patient's mouth.
Asepsis and antisepsis in surgery
A set of measures is used to prevent wound infection during tooth extractions.
Asepsis is a prevention system that prevents microorganisms from entering the wound. It includes instrument sterilization, special processing of the surgeon's hands, and adherence to specific techniques during surgery.
Antisepsis aims to destroy or reduce the number of microorganisms directly within the surgical field. The term was introduced in 1750 by the surgeon Pringle, and modern principles were established by I. Semmelweis and J. Lister.
Methods of antisepsis:
- Mechanical: washing the wound, excision of infected edges.
- Physical: drying with hygroscopic material, drainage, use of hypertonic dressings, aspiration of contents, and UV irradiation.
- Biological: use of vaccines, sera, bacteriophages, and antibiotics.
Stages of instrument processing
All dental devices contacting blood or the wound surface undergo a rigorous preparation cycle.
1. Disinfection Aims at complete or partial destruction of microorganisms. Instruments are soaked in solutions of potent antiseptics. Used materials are soaked in a 5% Alaminol solution for 60 minutes prior to disposal (if blood traces are present, an 8% solution is used). The skin of the surgical field is sequentially treated with 70% ethanol and a 2% iodine solution.
2. Pre-sterilization cleaning (PSC) Performed manually at room temperature:
- Rinse instruments under running water (2–3 minutes).
- Soak in distilled water (10–15 minutes).
- Use ultrasonic devices for small parts (e.g., the "Serga" device).
Important PSC rules: detachable items are soaked only in disassembled form, and instruments with lock joints (e.g., extraction forceps) in an open position. After PSC, all items must be thoroughly dried.
3. Sterilization The final stage ensuring the complete elimination of microorganisms and their spores from objects.
Types and devices for sterilization
Sterilization of surgical instruments is divided into physical and chemical.
Physical methods:
- Exposure to high temperatures: boiling, dry heat sterilization, and autoclaving (steam under pressure).
- Radiation: ultrasonic and ultraviolet.
Loading rules: in a dry heat sterilizer, instruments are placed in trays using the "well" method, while during autoclaving, dressing material is placed in special boxes (drum sterilizers / bixes).
Chemical ("cold") sterilization: Used for instruments that cannot withstand thermal stress (e.g., dental mirrors). Formalin, 1–3% chloramine solution, 6% hydrogen peroxide solution, "triple solution", or 70% ethanol are used.
Specifics of dental handpiece processing
Due to their complex internal structure, handpieces require specialized equipment.
- "Assistina" device: securely fixes the handpiece and injects disinfectant solution and lubricating oil inside under pressure.
- "Terminator" device: designed for ultra-fast express processing, handling cleaning and disinfection in just 3 seconds.
Following preliminary cleaning, surgical handpieces used in surgeries (including complex tooth extractions) must be steam sterilized at 140 °C.
Briefly: answers to topical questions
What methods of antisepsis are used in treating the surgical field?
Antisepsis is a system of measures aimed at reducing the number of microorganisms in the surgical field. Chemical methods of antisepsis are used when treating the surgical field.
- Skin of the surgical field — sequential treatment with 70% ethanol, 2% iodine solution, and other agents is performed.
- Oral cavity — before administering the anesthetic, the patient rinses the mouth with 0.12% chlorhexidine or 0.2% corsodyl.
What structural elements do tooth extraction forceps consist of?
Extraction forceps consist of several main and additional structural elements.
- Beaks — the working part for gripping the crown or root, featuring a groove with fine longitudinal serrations on the inner surface.
- Handles (shanks) — the part held by the surgeon to apply force.
- Lock — provides a movable connection between the beaks and handles.
- Transition part — present in some models between the lock and the beaks.
- Spring retainer — a return spring between the shanks for their automatic opening.
What stages does pre-sterilization cleaning (PSC) of surgical instruments include?
Pre-sterilization cleaning of surgical instruments includes several sequential stages.
- Washing — instruments are washed in running water for 2–3 minutes.
- Soaking — immersion in distilled water for 10–15 minutes (detachable items are soaked strictly in disassembled form, and instruments with lock joints in an open position).
- Additional cleaning — using special ultrasonic devices to remove mechanical contaminants from small instruments.
- Drying — after cleaning, instruments must be thoroughly dried.
An azopyram test is performed for quality control to detect occult blood.
For the removal of which teeth is a straight elevator used?
A straight elevator is used in oral and maxillofacial surgery to extract certain groups of teeth and their roots.
- Roots of maxillary teeth — the instrument is used to extract single roots by wedging the working end between the root and the alveolar margin.
- Atypically positioned teeth — used for the extraction of maxillary teeth with anomalous positioning.
- Mandibular third molars — used for luxation of lower wisdom teeth in a number of clinical cases.
What are the pathways of wound infection during tooth extraction?
There are five ways of wound infection:
- airborne;
- droplet;
- contact;
- implantation;
- mixed.
Which instruments are used to detach the circular ligament of the tooth (syndesmotomy)?
Specialized separation instruments are used to detach the gingival margin and the circular (circumanal/circular) ligament of the tooth.
- Syndesmotomes (desmotomes) — instruments consisting of a pear-shaped handle, a shank, and a blade (straight, sickle-shaped, or curved along the edge).
- Surgical separation spatulas — instruments with a pointed working end (e.g., a sickle spatula).
- Periotomes — also used for the preliminary stage of ligament detachment prior to tooth extraction.
Class and exam questions
How should a dental surgeon scrub their hands before extracting a tooth?
Surgical disinfection is performed: handwashing followed by antiseptic treatment (e.g., 0.5% alcohol chlorhexidine solution) for 2–3 minutes. Sterile rubber gloves must be worn afterward.
How to check if blood remains on surgical forceps after washing?
Chemical control is used — the azopyram test. If occult blood remains on the instrument, a violet coloration appears within one minute of reagent application, which then turns into a pink-lilac or brownish hue.
Where are small instruments, such as burs, sterilized?
Special glass-bead sterilizers are used for targeted sterilization of small dental items (burs, endodontic instruments).
What else to study on this topic
- Organization of the workspace and rules for arranging medical furniture.
- Detailed mechanism of the azopyram test and the chemical basis of the reaction.
- Features of using the "Serga" ultrasonic device for instrument cleaning.
- Specifics of packing dressing materials into drum sterilizers (bixes) for autoclaving.
Master the entire topic in the course "Surgical Dentistry"
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Dental Extraction Instruments" and 866 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 28 video lessons on the subject
Other topics in "Chapter 2. Organization and Equipment of the Dental Surgery Office (M.M. Pozharitskaya)"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.