Chairside Assisting for Dental Assisting Exam Study Guide (page 4)

Practice problems for this study guide can be found at:

Chairside Assisting for Dental Assisting Exam Practice Problems

The dental office has many exciting areas in which to be a team member. Chairside assisting is an example of one such area. Assistants are utilized to their fullest capabilities. They must possess extensive knowledge in order to truly be effective at the chair. Dentists appreciate assistants who can anticipate their needs as operators and help them treat their patients. Efficient chairside assistants will increase the overall production of dental practices by aiding dentists in completing their procedures more quickly and more effectively.

Concepts and Skills

Knowledge of the following concepts and skills are necessary to become a licensed, highly skilled, and efficient chairside dental assistant. Chairside assisting is divided into ten main topics:

• Layout of a Dental Office
• Equipment in the Operatory (Treatment Room)
• Chair Positions
• Light Positions
• Clock Concept of Operating Zones
• Delivery of Dental Care
• Local Anesthetics and Analgesics
• Dental Support Aides
• Other Duties of Dental Assistants
• Dental Specialties

Layout of a Dental Office

A dental office can be organized in many ways. Some dentists prefer to work out of many operatories, while others will choose to work out of two treatment rooms. All offices will have the areas listed below. An informed assistant should be cross-trained to assist the dentist in the best way possible.

Reception Area

Patients enter this area first when arriving at the dental office. First impressions are important. This area can be decorated in any way the dentist chooses, but it should be welcoming and calming. It is important to straighten up the reception area continually throughout the day.

Front Desk

The front desk handles the business operations of the dental office. The assistant at the front desk is responsible for making appointments, answering the phone, insurance billing, patient invoicing, treatment-plan presentation (in some offices), and handling all financial matters.

Operatory or Treatment Rooms

This is where all dental services are performed. The dentist will typically work out of several rooms, while the hygienist works out of one assigned treatment room.

Laboratory

This area has many uses. Dental appliances can be fabricated here or sent to an outside lab if the dentist chooses. Lab cases can be stored here, and, if needed, this area can serve as overflow storage for back stock. There is specialized equipment found in the lab, such as a dental lathe and model trimmers.

Sterilization Area (Central)

This area is often referred to as “Central” because most dental offices are arranged to situate the sterilization area in the middle of the office, and all operatories feed into this area. Instruments are processed here using an autoclave or a similar type of sterilizer.

Team Lounge

This area serves as a private area for the dental team members. Purses, lunches, and other personal belongings should be stored here during the workday.

Dentist’s Private Office

This area is where the dentist will be able to have privacy while reviewing and signing patient charts and for other private matters.

Equipment in the Operatory (Treatment Room)

The operatory, or treatment room, is the heart of the dental operation. It must be designed for efficiency and safety. The equipment in the operatory is divided into ten areas: light, dental chair and controls, portable unit, operator’s equipment, table top, rheostat, assistant’s stool, operator’s stool, operatory sink, and operatory computer.

Light

Each operatory is equipped with an overhead light to aid the dental team with illumination into the oral cavity. Some lights have a dimming switch to use while placing light-sensitive materials. Changing the position of the light is the responsibility of the dental assistant.

Dental Chair and Controls

There are many types of dental chairs from which the dentist can choose. Since sit-down dentistry is most common today, most chairs are built for that purpose. Controls can be located in any area of the chair the dentist chooses. Currently, the most common way to control a dental chair is via foot controls. These controls can be pre-programmed to the positions the dentist prefers. The patient dental chair is contoured for the patient’s comfort. Newer models come with a massager and heat. The chair can be positioned in one of three ways: upright (used for taking impressions, exposing dental radiographs, and seating and dismissing the patient), supine (patients are reclined on their back), and subsupine (used for emergency situations).

Portable Unit

The portable unit consists of the high-volume evacuator (HVE), the saliva ejector, and the air/water syringe (triplex syringe).

High-Volume Evacuator (HVE)

This is a high-speed suction device used by the assistant for removing debris, particles, and large amounts of water very quickly from the oral cavity.

Saliva Ejector

This is a slow-speed suction device used by assistants for removing saliva only.

Air/Water Syringe (Triplex Syringe)

This device is capable of performing three functions. It can blow air, spray water, or “blast” a combination of air and water. The assistant utilizes this device while handling the HVE or saliva ejector.

Operator’s Equipment

The dentist’s equipment includes two types of hand pieces—high-speed and low-speed—as well as the air/water syringe.

High-Speed Hand Piece

This is commonly known as the drill. This piece of equipment is used by the dentist to prepare the tooth to receive a restoration.

Low-Speed Hand Piece

This piece of equipment is used by the dentist, along with the high-speed hand piece, to remove soft decay, polish a restoration, or complete a prophy.

Table Top

This is where the assistant will place the instruments on the tray or in their cassette for the specific procedure. The table top is also known as the “mobile cart.”

Rheostat

This “foot pedal” controls the dental hand pieces.

Assistant’s Stool

This chair is designed specifically for the way an assistant sits at the dental chair. The stool is equipped with wheels and castors, a comfortable cushion, a lever to adjust the height, a foot ring, and often a belly bar for abdominal support.

Operator’s Stool

This chair is designed specifically for the operator and the way she or he is positioned at the dental chair. This stool has a low adjustable backrest, a comfortable cushion, a lever to adjust both the backrest and height, and wheels and castors. There is never a ring on an operator’s stool. The dentist should be able to sit with his or her feet flat on the floor. For maximum visibility, the dental assistant’s stool should be four to six inches above that of the operator.

Operatory Sink

Each treatment room has at least one sink. Typically, there will be a sink on both the operator’s side and the assistant’s side.

Operatory Computer

Today’s operatory is usually equipped with a computer that runs dental office software. It can be utilized for one or all of the following:

• accessing the patient’s electronic chart
• digital X-rays
• intraoral images
• treatment plan for the patients

Chair Positions

Dental chairs are the centerpiece of the operatory. They are adjustable to accommodate patients of all shapes and sizes. The three main positions are upright, supine, and subsupine.

Upright

The patient enters and leaves the dental chair in the upright position.

Supine

Dental treatment is performed in this position. The supine position places the patient flat on his or her back, with the head in line with the knees.

Subsupine

Dental treatment can be performed in this position if the dentist desires. The subsupine position places the patient’s head below her or his knees. This position also places the patient’s head directly in the operator’s lap. This is used for emergencies.

Light Positions

The operating light is an essential part of the equipment in the treatment room. It must be placed correctly to illuminate the area to be treated. There are two main light positions: maxillary and mandibular.

Maxillary Position

The light is positioned over the patient’s chest. Once the light is switched on, the beam should be directed toward the maxillary by gently pulling the light forward to the patient’s chin and then tipping it upward.

Mandibular Position

The light is positioned over the patient’s chest. Once the light is switched on, it should be pulled forward until it is directly over the patient’s mouth. The beam should be shining directly onto the mandibular teeth.

Clock Concept of Operating Zones

The dentist and assistant must work in harmony as a coordinated team. Operating zones define what activities take place in which areas. These zones are defined based on the hands of a clock. There are four defined zones: static zone, assistant’s zone, transfer zone, and operator’s zone. These zones differ for right-handed and lefthanded operators.

Right-Handed Operator

The four clock zones (based on clock positions) for the right-handed operator are as follows:

• 12–2 = Static Zone
• 2–4 = Assistant’s Zone
• 4–7 = Transfer Zone
• 7–12 = Operator’s Zone

12–2 = Static Zone

This is the clock zone where very little occurs.

2–4 = Assistant’s Zone

This is the clock zone where the assistant sits while assisting for chairside procedures.

4–7 = Transfer Zone

This is the clock zone where instrument transfer takes place. The assistant hands instruments and medicaments from the instrument tray to the operator through this zone.

7–12 = Operator’s Zone

This is the clock zone where the operator sits and performs all dental procedures.

Left-Handed Operator

A left-handed dentist also has the four operating zones, but they are reversed.

• 12–5 = Operator’s Zone
• 5–8 = Transfer Zone
• 8–10 = Assistant’s Zone
• 10–12 = Static Zone

The descriptions of these zones are the same as those for the right-handed operator. However, the clock times are switched.

Delivery of Dental Care

Four-handed dentistry involves the operator and one assistant working together at the chair, while six-handed dentistry involves the dentist and two assistants working together at the chair. One assistant is the chairside assistant, and the other is the roving assistant. The chairside assistant is responsible for patient safety and for maintaining a clean, debris-free environment in the oral cavity. The roving assistant is responsible for instrument transfer, mixing of materials, and the pace of the procedure.

Techniques of Four-Handed Dentistry

Four-handed dentistry is also known as team dentistry because the dentist and the assistant work closely together in a coordinated manner.

Instrument Grasps

Various grasps are utilized by the operator depending upon the instrument of choice. These grasps include pen grasp, palm grasp, modified pen grasp, and modified palm grasp. There are two main HVE grasps: thumb-to-nose grasp, and pen grasp. In the thumb-to-nose grasp, the assistant holds the HVE in this grasp for maximum control of the HVE. The hand is wrapped around the HVE, with the thumb pointed toward the patient’s nose. In the pen grasp, the assistant utilizes this grasp primarily for assisting with dental treatment performed in the anterior area of the oral cavity.

Fulcrum

Fulcrum is a resting point for the operator’s working hand. A fulcrum allows for stability and control while utilizing an instrument or dental hand piece in the patient’s mouth.

Direct and Indirect Vision

The operator utilizes both direct and indirect vision while performing dental treatment. Direct vision is when the operator has a direct line of sight to the area of the mouth on which she or he is working. Indirect vision is when the operator looks into a mouth mirror to visualize the area of the mouth being worked on. The assistant is responsible for spraying air on the mouth mirror to keep the dentist’s line of vision clear.

Instrumentation

Generalized: In a general dental office, one will find a wide variety of dental instrumentation from each specialty. There will be a limited amount of specialized instrumentation, depending on how often the general dentist performs that specialty procedure. Some instrument setups found in a general dental office are basic setup, restorative set-up, crown and bridge setup, and emergency setup.

Specialized: In a specialty office, one will find instruments specific to that specialty. For example, an orthodontic office will have a specific instrument setup for cementation of bands, bonding of brackets, adjustment of arch wire, changing of elastics, and removal of orthodontic appliances.

Hand-Piece Identification and Utilization: High-speed hand pieces are all one unit, spray water, and have a fiber-optic light. They rotate at 450,000 rpm, are used for preparation of teeth for restorations, and are slightly angled. Hand pieces are designed to spray water to wash away debris and to keep the tooth cool and prevent overheating. Slow-speed hand pieces have multiple parts and attachments, with a motor in the base. Attachments include straight, contra-angle, and prophy-angle.

Bur Identification and Utilization: Dental burs are drill bits used in hand pieces. There are two main types of burs—carbide and diamond. The three bur shanks are straight, friction grip, and latch type. The three parts of the bur are the shank, neck, and head. The head of the bur cuts the tooth structure, and comes in many shapes. Burs are inserted into hand pieces to perform dental treatment.

Hand Instruments

Hand instruments are classified according to their use. Hand-cutting instruments are those used by the dentist to cut actual tooth structure (usually dentin). Hand-carving instruments are used to “carve anatomy” into the restorative material (amalgam). Exploratory instruments, also known as exam instruments, are used to perform an intraoral examination. This set includes the mouth mirror, explorer, cotton forceps, and a periodontal probe. The mouth mirror is used to retract the cheeks, lips, and tongue, as well as to reflect light and provide indirect vision.

Another category of hand instruments are accessory in nature. Crown and bridge scissors, articulating paper holders, and dappen dishes are a few examples. Articulating paper holders secure the colored marking paper used to identify high spots on a newly placed restoration (amalgam, composite, crowns, bridges, dentures, or partials).

Other Duties of Dental Assistants

Before dental procedures even begin, the dental assistant must welcome the patient into the operatory and make him or her comfortable. It is customary for the dental assistant to take the patient’s pulse and blood pressure. Normal resting pulse rate is between 60 and 100 beats per minute. Blood pressure consist of two numbers, the higher one being the systolic and the lower the diastolic. Normal blood pressure is considered to be 120 over 80.

Clinical and Periodontal Charting

It is important for the dental team to keep good records, and charting is an essential part of that. Traditional records were kept on paper charts, but today, more and more dental offices are computerizing charts.

Black’s Cavity Classifications

Black’s Cavity Classifications describes the location of the decay on the tooth. It includes six classes according to the location of the cavity. The system also suggests the best way of restoring the tooth. For example, in perio charting, Class II indicates moderate mobility. In orthodontics, patients are screened by their occlusion. Once established, the orthodontist will classify the type of malocclusion according to Angle’s classification. Class I is normal, Class II is distocclusion where the maxillary teeth stick out beyond the mandible in an abnormal degree, giving the appearance of buck teeth. Class III is known as mesiocclusion and the mandible juts out anterior to the maxilla. For example, an occlusion with tongue thrusting is a Class II.

Tooth Preparation

During a composite procedure, the steps of tooth preparation basically mirror that of an amalgam restoration. Once the tooth is prepared with orthophosphoric acid (etchant) and the bonding agent is placed, a clear plastic mylar strip (or celluloid strip) is placed to act as a matrix. The clear matrix allows for operator visibility, as well as for the curing light to polymerize the composite material. The composite will not stick to or become discolored from the mylar material.

Tooth Staining

Staining of the teeth can come from several sources. Stains are categorized according to their location and source. Extrinsic stains occur on the outside of the tooth structure, while intrinsic stains are integrated into the tooth itself. Exogenous stains occur from sources outside of the tooth (smoking, drinking coffee and colas, etc.). Extrinsic stains are removed during the coronal polishing portion of a dental prophylaxis, or by using bleaching techniques.

Dental Specialties

Each specialty uses highly specialized instrumentation and procedure setups. There are nine dental specialties, as listed below:

• endodontics—treatment and diseases of the dental pulp
• periodontics—treatment of the diseases of the supporting structures, gingiva, and alveolar bone of the oral cavity
• pediatric dentistry—treatment of children from birth through adolescence
• orthodontics and dentofacial orthopedics—treatment and correction of all forms of malocclusion
• prosthodontics—restoration of oral function by restoring natural teeth or replacing missing teeth with a prosthesis (denture, partial, bridge, or implant)
• oral and maxillofacial surgery—diagnosis and surgical treatment of diseases, injuries, and defects of the oral and maxillofacial regions
• oral and maxillofacial pathology—diagnosis and treatment of abnormalities of the soft tissues and surrounding oral region
• oral and maxillofacial radiology—production and interpretation of X-ray images
• dental public health—promotes dental health in the community; prevents and controls dental diseases via educational means

Oral and maxillofacial surgeons extract teeth, biopsy lesions (abnormalities), correct anatomical defects, and place dental implants, to name a few procedures. For instance, rongeurs are used to contour the alveolar bone to eliminate sharp edges prior to the fabrication of a complete or partial denture. After an extraction, some patients experience alveolitis, also commonly known as a “dry socket.” This occurs due to the loss or lack of development of a healthy blood clot in the alveolar socket. A surgical dressing is placed in the alveolus until adequate healing has occurred.

Pediatric dentists treat children from newborn through adolescence. Older patients with special needs may continue to be treated by the pediatric dentist. Patients with physical or mental disorders can be treated in a hospital under the care of a pediatric dentist with hospital privileges. All others are seen in the pediatric dental office. Aside from the regular dental procedures, pediatric dentists also treat many emergencies seen in children. For instance, traumatic intrusion occurs when a tooth has been forced inward by a fall or sports injury. Avulsion occurs when the tooth is completely knocked out of the alveolar socket.

In the specialty of endodontics, the dentist treats diseases of the pulp and surrounding tissues. Pulpal irritation can be classified as reversible pulpitis or irreversible pulpitis. In reversible pulpitis, the dentist places a sedative medicament over the pulpal floor in order to give the pulp time to heal and calm down. If this works, further treatment is not necessary at this time. Irreversible pulpitis occurs when the pulp becomes infected or dies due to trauma or decay. Root canal therapy is then performed by the dentist unless the patient chooses an extraction.

During the course of a root canal, the dentist cleans out and enlarges the canal(s) of the tooth. This is done using small instruments such as broaches, reamers, and files. Once the chamber is uniform in size and enlarged enough to accept the final filling material, the doctor will irrigate the canal(s) with a mixture of sodium hypochlorite and water. This step will “sterilize” the canal by removing any tissue particles or debris from the small chamber of the canal. The canal is thoroughly dried with paper points prior to the placement of the gutta percha filling material. The gutta percha is cemented into the canal with a sealer cement.

Specialty Procedures

Below is a list of common procedures performed by each specialty:

• endodontics—root canals, specialized diagnosis, post placement
• periodontics—root planning, perio hygiene, graphs, gingivectomy, gingioplasty, osseous surgeries
• pediatric dentistry—coronal polishing, stainless-steel crowns, pulpotomies, fluoride treatments, restorations, space maintainers
• orthodontics—invisalign, placement of full appliance, appliance adjustment, retainers, positioners, debanding and banding, palatal expander placement
• prosthodontics—implant crowns, crowns and bridges, full dentures, partial dentures, denture abutments
• oral and maxillofacial surgery—simple and surgical extractions, multiple extractions, facial reconstruction, removal of tumors and oral lesions, postoperative appointments
• oral and maxillofacial pathology—exfoliative biopsy, incisional biopsy, excisional biopsy, growth of cultures, microscopic evaluations
• oral and maxillofacial radiology—production and interpretation of X-ray(s) for diagnosis and treatment of diseases of the upper jaw and face
• dental public health—outreach programs, volunteer clinics, school educational programs, elderly outreach

As you can see, there is much that chairside assistants must know. Each of the previously mentioned skills and knowledge can be expanded upon and further developed. In addition to those skills and knowledge, the chairside assistant must also be familiar with and well versed in numerous other skills (see below), which will be covered in subsequent chapters of this book:

• dental materials—armamentarium and manipulation of cements, liners, impression materials, restorative materials, and so on
• dental radiology—the exposure, processing, mounting, and evaluation of dental films, including regard for patient safety while exposing X-rays 
• infection control—treatment-room setup; PPE; aseptic technique during procedures; sterilization of instruments; and the disinfection of treatment room, equipment, and supplies
• additional duties—knowing and understanding state and federal laws regulating dental assisting duties; the importance of ethical behavior; the anatomy of the oral cavity; and how to cope with medical emergencies

Practice problems for this study guide can be found at:

Chairside Assisting for Dental Assisting Exam Practice Problems