5.1.3 File Selection

The instrument presents a library of files from major brands. Users can choose to use files without setting them up. To enter the NITI system, choose the manufacturer and system by pressing the NITI system name according to your needs. Press < or > to switch pages, and press X to exit selection. After selection, the status bar on the main page displays the selected NITI system.

System Name according to your needs:

• Press ▶️ to enter the NITI system, choose manufacturer and systems by pressing NITI system name according to your needs.
• Press ◀️ to switch pages and press ❌ to exit selection.

[Image Description: A screenshot of the 'File System' interface showing a list of manufacturers like COXO, Dentsply Sirona, VDW, and associated systems like SC-Pro, S-One Pro, WaveOne Gold, RECIPROC/blue, Protaper Gold, VDW.ROTATE, SC-Pro Lite 2018, Protaper Next, Mtwo, S-One 2018, TruNatomy, FlexMaster.]

B2: File manufacturer

B3: NITI system name

B4: User can also press ▶️ (B4) to select different NITI system under the same manufacturer.

5.1.4 Handpiece LED Light

Press ⚙️ to enter setup state.

a) Press ▶️ to change the LED status as below:

• High
• Medium
• OFF

When the LED is off, otherwise the LED will light up when the motor is running.

b) Press button as below to select delay time:

• +0s (0s delay)
• +1s (1s delay)
• +3s (3s delay)
• +5s (5s delay)

After the motor stops running, the LED will continue to light up until the delay time expires.

5.1.5 Torque Reverse

a) Press ▶️ to turn on torque reverse.

During operation, when load reaches preset torque limit value, the motor will automatically reverse. When the load is reduced, the motor will automatically return to forward rotation.

[Image Description: A diagram illustrating torque reverse. The first panel shows 'Load within the torque limit value', indicating normal forward rotation. The second panel shows 'Load beyond the torque limit value', indicating reverse rotation. The third panel shows 'When the load is reduced, the motor is automatically restored', indicating a return to forward rotation.]

b) Press ▶️ to turn off torque reverse.

During operation, when load reaches preset torque limit value, the motor will stop. Restart handpiece to restart the motor.

CAUTION

During operation, do not apply excessive force to the file.

5.1.6 Rotary Direction

Before working, press ▶️ on the screen or long press ⚙️ on the handpiece to change rotary direction.

During working, user can only change the direction by long press ⚙️ on the handpiece.

During working, the icon means:

• ▶️ (Clockwise rotary)
• ⚙️ (Counterclockwise rotary)

5.1.7 Calibration

(Refer to 8.4)

5.1.8 Start Working

Press ▶️, the motor rotates according to the set speed and rotary direction, press again to stop it.

[Image Description: A screenshot of the 'Start Working' interface showing current settings: RPM 350, Ncm 3.0, and torque reverse status 'Torque reverse on'. It also displays a visual representation of a root canal with file progression and indicator bars showing different file sizes (17/.08, 19/.02, 20/.04, 25/.04) and their corresponding settings.]

Currently torque: When the torque exceeds the set limit, the motor will stop or automatically reverse (refer to 5.1.5).

5.1.9 Change Speed and Torque

Usually, the default settings do not need to be adjusted; however, user can modify the default speed and torque values.

CAUTION

User should refer to the file manufacturer's instructions to adjust the speed and torque.

5.1.10 User System

The instrument contains two user systems: Rotary File and Recipro File.

a) Rotary File

There are 5 continuous rotary files in the system, and the user can set speed and torque as required.

b) Recipro File

There is a reciprocation rotary file in the system, and the user can set speed and rotation angle as required.

[Image Description: A screenshot of the 'User System' interface. It shows options to select between 'Rotary File' and 'Recipro File'. For Rotary File, it displays settings for RPM, speed, and torque. For Recipro File, it shows settings for RPM, degree (rotation angle), and torque reverse.]

5.2 Apex Locator Mode

If the root apex test wire is connected to the handpiece, it enters the Apex Locator Mode automatically.

5.2.1 Connection Accessories

Connect the components: lip Hook, file clip, root apex test wire, and handpiece.

[Image Description: A diagram showing the connection of accessories: a handpiece, a file clip attached to a file, a lip hook, and a root apex test wire connecting the file clip and lip hook to the handpiece.]

CAUTION:

• Do not use a damaged or worn file clip. This will cause inaccurate measurement.
• Do not bump the plugs and wind the probe cord around the instrument.
• Make sure the plug is all the way in. This will cause inaccurate measurement.

5.2.2 Interface Overview

A: Apex Locator Function

B: Root apex area, shows the root apex area and indicates where the file was reached.

C, D: Apical reference position (The number represents the relative position of file tip and apical hole; the smaller the value, the closer to the apical hole).

E: Set the DR's CHOICE apex position.

F: Complete root canal image, shows file entering the root canal opening.

Apex enlargement area:

• Indicators indicate the exact position and change accordingly from blue to green and then to yellow as shown below.

[Image Description: A visual progression of apex locator indicators: 'Blue (Close to Apex Area)' shows a file tip far from the apex. 'Green to yellow (Reach Apex Area)' shows the file tip getting closer to and reaching the apex.]

• File movement is accompanied by audio signals as additional indication of file position. The shorter the sound interval, the closer the distance between file and apex.
• When file reaches apical foramen, indicators are marked red and a constant sound is emitted.

5.2.3 Set the DR'S CHOICE apex position

Press E on the screen to set the DR's CHOICE apex position, and then clear visual and audio indication is given that the file has reached the pre-selected position.

5.2.4 Operation Check

It is recommended to check the performance of the apex locator once a week. The detailed methods refer to 8.1 and 8.2.

5.2.5 Measurement

A WARNING:

• Do not allow lip hook, file clip, and test wire to contact with power sources, such as power outlets.
• Make sure that all connectors are securely locked in place.

Hook the lip hook in the corner of the patient's mouth and slowly insert the file into the canal. The file movement in the canal is shown on the full canal image as below.

[Image Description: A diagram showing the process of inserting a file into a root canal. The first panel shows the file being inserted. The second panel shows the file moving within the canal, with an indicator bar showing its position relative to the apex. The third panel shows the file reaching the apex.]

5.2.6 Electric Measurement of Root canal length

(Refer to 7)

5.3 Multi-function Mode

If lip hook wire is connected to handpiece, it enters the Multi-function Mode automatically.

5.3.1 Connection Accessories

Connect the components: handpiece, contra-angle, file, lip hook, lip hook wire.

a) Connect contra-angle (Refer to 5.1.1)

b) Connect file (Refer to 5.1.1)

c) Connect lip hook and lip hook wire.

[Image Description: A diagram showing the connection of accessories for multi-function mode: handpiece, contra-angle, file, lip hook, and lip hook wire.]

CAUTION

• Do not use a damaged or worn file clip, file, and contra-angle.
• Do not bump the plugs and wind the probe cord around the instrument.
• Make sure the plug is all the way in.

5.3.2 Interface Overview

[Image Description: Two screenshots of the 'Interface Overview' for the COXO SC-Pro. The left screenshot shows settings for a Rotary file (RPM 350, Ncm 3.0, Torque Rev). The right screenshot shows settings for a Recipro file (RPM 350, Deg. R30, Torque Rev). Both interfaces display file selection options.]

NOTE:

• Exceed the DR'CHOICE, Apex locator indicator flashes.

5.3.3 File Selection

(Refer to 5.1.3)

5.3.4 Handpiece Light

(Refer to 5.1.4)

5.3.5 Torque Reverse

(Refer to 5.1.5)

5.3.6 Rotary Direction

(Refer to 5.1.6)

5.3.7 Calibration

(Refer to 8.4)

5.3.8 Set the DR's CHOICE apex position

(Refer to 5.2.3)

5.3.9 Operation Check

It is recommended to check the performance of the apex locator once a week. The detailed methods refer to 8.1 and 8.2.

5.3.10 Start Working

(Refer to 5.1.1 and 5.2.5)

In multi-function mode, when the file is in contact with the root canal, length is measured. The movement of the file is displayed on the right side of the screen, accompanied by different prompt sounds.

5.3.11 Change Speed and Torque

(Refer to 5.1.9)

5.3.12 Electric Measurement of Root canal length

(Refer to 7)

6. Battery and Charging

6.1 Battery Power

[Image Description: Two screenshots of the COXO SC-Pro interface showing battery status. The left shows 'Handpiece power' with a battery icon indicating over 70% charge. The right shows 'Control unit power' with a battery icon indicating 20-70% charge.]

Battery:

• >70% power
• 20-70% power
• <20% power, low battery level, please charge it in time.
• <5% power, very low battery level.

CAUTION:

• When control unit or handpiece battery is less than 5%, the ⚠️ icon will appear on screen.
• Non-professionals cannot replace the battery.

6.2 Charging

a) Control Unit: Connect handpiece and adapter to charge the handpiece; the charging status is shown as follows:

[Image Description: Diagrams illustrating the charging status of the control unit. Four panels show a sequence of charging: a battery icon with a lightning bolt, indicating charging in progress.]

b) Handpiece:

External charging: Connect control unit and adapter, and place handpiece on handpiece charger to charge.

Internal charging: Control unit can charge handpiece without external input.

• Press ⚙️ to enter setup state and then press ▶️ or ❌ to turn on/off internal charging.

[Image Description: A screenshot showing the 'Setup' menu with an 'Internal charging' toggle switch, indicating 'Control unit charges handpiece without external input'.]

The function turns off when control unit battery level is less than 20%.

A WARNING:

• Only use the adapter provided by manufacturer.
• Do not charge in humid places.

[Image Description: Diagrams showing the handpiece charging process. Panel 'a' shows connecting the handpiece to the charger. Panel 'b' shows placing the handpiece on the charger. Panel 'c' shows the handpiece charging. Panel 'd' shows the handpiece fully charged.]

6.3 Replacement Battery

a) Open the rubber cover or remove the screw;

b) Remove the battery cover as shown in the illustration;

c) Remove the old battery;

d) Connect the new battery;

e) Install the cover and its screw or rubber cover.

[Image Description: Diagrams illustrating the battery replacement process for the control unit. Panels a, b, c, and d show steps for opening the cover, removing the battery, connecting a new battery, and reassembling.]

CAUTION:

• Only use original battery.
• Do not use a battery if it is leaking, deformed, discolored, or if its label is peeled off. It might overheat.

¡NOTE:

• Turn off power before replacing the battery.
• Avoid opening the rubber cover too hard.
• Do not remove the battery cover if the handpiece is wet.
• Do not tighten the cover screw too much. This could strip the threads.
• Dispose of old batteries in an environmentally safe way and in strict according to local regulations.

7. EMR (Electric Measurement of Root canal length)

Accurate measurement cannot be obtained with the root canal conditions shown below.

• A huge apical hole: Root canal that has an exceptionally large apical foramen due to a lesion or incomplete development cannot be accurately measured.
• Root canal with blood overflowing from the opening: If blood overflows and contacts the gums, it will cause electrical leakage, and accurate measurement results cannot be obtained. After the bleeding has completely stopped, thoroughly clean the inside of the root canal and the opening, and then perform the measurement.
• Root canal with a chemical solution overflowing from the opening: An accurate measurement cannot be obtained if chemical solution is overflowing from the canal opening. In this case, clean the canal and its opening. It is important to get rid of the solution overflowing the opening.
• Broken crown: If the crown is broken and a section of the gingival tissue intrudes into the cavity surrounding the canal opening, contact between the gingival tissue and the file will result in electrical leakage and an accurate measurement cannot be obtained. In this case, build up the tooth with a suitable material to insulate the gingival tissue.
• Fractured tooth: Leakage through a branch canal. Fractured tooth will cause electrical leakage and an accurate measurement cannot be obtained. A branch canal will also cause electrical leakage.
• Re-treatment of a root filled with gutta-percha: The gutta-percha must be completely removed to eliminate its insulating effect. After removing the gutta-percha, pass a small file all the way through the apical foramen and then put a little saline in the canal, but do not let it overflow the canal opening.
• Crown or metal prosthesis touching gingival tissue: Accurate measurement cannot be obtained if the file touches a metal prosthesis that is touching gingival tissue. In this case, widen the opening at the top of the crown so that the file will not touch the metal prosthesis before taking a measurement.
• Cutting debris on tooth: Thoroughly remove all cutting debris on the tooth.
• Pulp inside canal: Thoroughly remove all the pulp inside the canal. Otherwise, an accurate measurement cannot be obtained.
• Caries touching the gums: In this case, electrical leakage through the caries infected area to the gums will make it impossible to obtain an accurate measurement.
• Blocked canal: The meter will not move if the canal is blocked. Open the canal all the way to the apical constriction to measure it.
• Extremely dry canal: If the canal is extremely dry, the meter may not move until it is quite close to the apex. In this case, try moistening the canal with oxydolor saline.

8. Maintenance

8.1 Check with Tester

• Connect tester to handpiece;
• Confirm whether indicators are lit between 0.1-0.5.

[Image Description: A diagram showing a tester connected to the handpiece. An indicator display shows a range from 0.0 to 1.0, with a target range highlighted between 0.1 and 0.5.]

WARNING:

If indicators are not lit between 0.1-0.5, stop using the equipment immediately and repair it.

8.2 Check Canal Measurement Function

8.2.1 Check Test Root Apex Test wire

Check the test root apex test wire and confirm whether indicators are lit.

[Image Description: A diagram showing the test root apex test wire connected to the handpiece. An indicator display shows a root canal with a file progressing, and colored indicators (red, yellow, green) representing the file's position relative to the apex.]

8.2.2 Check Lip Hook wire

Check the lip hook wire and confirm whether indicators are lit.

[Image Description: A diagram showing the lip hook wire connected to the handpiece. An interface displays file selection options and settings for RPM and torque.]