1. Dentist position and Moisture control
Operative Dentistry
Dentist position and Moisture control
Asst. prof. dr.Emad farhan alkhalidi

2. Dentist position
Chair position is a very important aspect in the success of a dental treatment.
The correct positioning helps the operator to have a good visibility and accessibility of the oral cavity
If operator maintains proper position, the operator is less likely to get strain, fatigue, and less chances of getting musculoskeletal disorders.

3. Chair position
For restorative dental procedures, the most preferred operating positions are:
Upright position, The initial position.
Almost supine, patient Head, knees and feet are approx. At same level.
Reclined 45 degree, Patient’s head should not be lower than feet except in case of syncopal attack.
The most common patient positions for operative dentistry are almost supine or reclined 45 degrees.

4. Chair position

5. Operating positions
For better understanding, sitting positions of operator are related to a clock.
The operator's positions:
(right handed operator)
7 o'clock, 9 o'clock, 11 o'clock, and 12 o'clock
Left handed operator's positions ,
5 o'clock, 3 o'clock and 1 o'clock. 7

6. Operating positions Right front position (7 o'clock)
It helps in examination of the patient
Working areas include:
Mandibular anterior
Mandibular posterior teeth (right side)
Maxillary anterior teeth

7. Operating positions Right position (9 o'clock)
In this position, dentist sits exactly right to the patient
Working areas include:
Facial surfaces of maxillary right posterior teeth
Facial surfaces of mandibular right posterior teeth
Occlusal surfaces of mandibular right posterior teeth.

8. Operating positions Right rear position (11 o'clock)
In this position, dentist sits behind and slightly to the right of the patient and the left arm is positioned around patient's head
This is preferred position for most of dental procedures
Most areas of mouth are accessible from this position either using direct or indirect vision
Working areas include:
Palatal and incisal (occlusal) surfaces of maxillary teeth
Mandibular teeth (direct vision).

9. Operating positions Direct rear position (12 o'clock)
Dentist sits directly behind the patient and looks down over the patient's head during procedure.
Working areas are lingual surfaces of mandibular teeth.
This position has limited application.

10. Considerations regarding patient position:
While doing work in maxillary arch, maxillary occlusal surfaces should be perpendicular to the floor.
In mandibular arch, mandibular occlusal surface should be oriented 45° to the floor.
Maintain proper working distance during dental procedure.
Operator should not rest forearms on the patient's shoulders and hands on the face of the patient.

11. Considerations regarding patient position:
5. Dentist should not use patient's chest as a instrument tray.
6. The operator should leave left hand free during most of dental procedures for retraction using mouth mirrors or fingers of left hand.
7. Operator should keep changing position if procedure is of long duration to decrease the muscle strain and fatigue.

12. Moisture Control
Moisture Control The process of removing excess sulcular fluid, saliva and gingival bleeding from the operative field. And preventing the inspiration of debris, hand piece spray and any other objects.
Moisture control aids: 
Absorbents. such as cotton rolls and cellulose wafer are useful for short periods of isolation example for examination. Where rubber dam application may not be possible.

13. Moisture control aids:
Rubber Dam. Best way for moisture control. It is a flat , thin sheet of latex or non latex that is held by a clamp (retainer) and a frame, that is perforated to allow the teeth that will be worked on to protrude through the perforations in the sheet while all the other teeth are covered and protected by the rubber dam. It is used to define the operating field by isolating one or more teeth from oral environment.

14. aids: Moisture Control
Saliva Ejectors The saliva ejector removes saliva that collects on the floor of the mouth. It is used in conjunctions with sponges cotton rolls and the rubber dam during less invasive dental procedures.
High Volume Evacuators. High volume evacuators are preferred for suctioning water and debris from the mouth when high speed handpiece is used.
The combined use of water spray and high volume evacuator has the following advantages. 1. Restorative and tooth debris are removed from the operating site. 2. Access and visibility are improved. 3. No dehydration of oral tissues.

15. aids: Moisture Control
Alternative isolation aids Retraction cord when properly applied can be used for isolation and retraction in the direct procedures of treatment of cervical lesions in facial veneering as well as in indirect veneers. Help prevent abrasion of gingival tissue during cavity preparation
Anti-salivary drugs To control salivation is rarely indicated Operator should be familiar with its indications contra indications and side effects of the drug to be used. Some Anti histaminics cause dryness of mouth due to anti cholinergic action