study models 101 trimming
TRANSCRIPT
![Page 1: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/1.jpg)
04/13/2023 1
Study Models 101Kathy Malone RDH, EFDA, CDA,BS
![Page 2: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/2.jpg)
04/13/2023 2
Trimming
![Page 3: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/3.jpg)
3¼ “
The cut is made at a 90 degree angle to the midline of the palate
Trim the model with the longest anterior/posterior length firstUsually the maxillary arch
Trimming the Posterior Border
![Page 4: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/4.jpg)
04/13/2023 4
Trimming the Posterior Border
You may draw a light line on the model to help with trimming.
Keep the line parallel with the wheel
![Page 5: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/5.jpg)
04/13/2023 5
Articulate the untrimmed half with the trimmed half
• Use the trimmed half as a template.
• When the trimmed half just touches the wheel stop trimming!( You will see bubbling)
• The models will remain articulated when placed on the counter top
• Follow this guideline for the rest of the trimming cuts.
![Page 6: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/6.jpg)
04/13/2023 6
Trimmed cut has not met the wheel. Continue until both halves meet.
Untrimmed Trimmed
![Page 7: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/7.jpg)
04/13/2023 7
Both trimmed and untrimmed cuts meet the wheel
![Page 8: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/8.jpg)
04/13/2023 8
Notice how the posterior cuts are even on both models when articulated
• The borders of both halves should be even on all cuts and remain articulated when placed on a counter for viewing.
![Page 9: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/9.jpg)
5Incorrect
Correct
Trim the widest model first--Usually the maxillary arch
Maxillary Arch
Trimming the Lateral Borders
![Page 10: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/10.jpg)
04/13/2023 10
Trimming the Lateral Borders
Keep the line parallel with the wheel
You may draw a light line on the model to help with trimming. The markings on the buccal cusps in this example are made dark for illustration purposes only. Dark lines will mar the final study model.
Trimmed side
![Page 11: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/11.jpg)
04/13/2023 11
Notice how the lateral cuts are even on both models when articulated
![Page 12: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/12.jpg)
04/13/2023 12
Keep the muccobuccal fold!!!
![Page 13: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/13.jpg)
04/13/2023 13
This is too close!!!
![Page 14: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/14.jpg)
6 6
Correct Incorrect
Trim from the midline of the canine to the midline of the arch and repeat on the opposite side.
Trimming Maxillary Anterior Borders
![Page 15: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/15.jpg)
04/13/2023
Trimming Maxillary Anterior Borders
15
You may draw line on the model to help with trimming.
Use the midpalatine suture as a midline guide. The patient’s dentition midline may not be the middle.
Keep the line parallel with the wheel
Trimmed
![Page 16: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/16.jpg)
04/13/2023 16
Trimming Maxillary Anterior Borders
![Page 17: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/17.jpg)
7 7
Mandibular Arch
You can initially trim this arch with a point and then remove it so the models will articulate
Trimming Mandibular Anterior Border
![Page 18: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/18.jpg)
04/13/2023 18
Trimming Mandibular Anterior Border
• Mandibular anterior border is rounded. You may initially trim with a point utilizing the maxillary arch model to insure articulation. Remove the tip to make the rounded appearance.
Remove Point
![Page 19: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/19.jpg)
88
Incorrect
Correct
Trim the heels at a 90 degree angle to an imaginary line from the midpoint of the canine and repeat at each side.
Trimming the Heel
![Page 20: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/20.jpg)
04/13/2023 20
Trimming the Heel
• Notice the line drawn from the point of the canine to the back corner.
• The cut should be perpendicular to the line.
![Page 21: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/21.jpg)
04/13/2023 21
Trimming the Heel
Trimmed Untrimmed
![Page 22: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/22.jpg)
04/13/2023 22
Trimming away Excess Stone for Visibility
Notice the difference between the untrimmed side and trimmed side.
Use bur on lathe or buffalo knife to trim away the excess.
![Page 23: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/23.jpg)
04/13/2023 23
The dentition must be visible. Remove excess stone with a bur on the lathe or a buffalo knife.
Stone in the way and dentition cannot be seen
Stone removed and dentition can be seen.
![Page 24: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/24.jpg)
04/13/2023 24
Cleaning Up After Trimming• Rinse off the wheel and base plate
with sprayer.• Wipe off the countertop and
cabinets.– The stone will streak on the
countertops!
• Clean the sink.• Wipe off the bur on the lathe.• Empty lathe tray.• Clean off the lathe shield.• Sweep the floor.• Clean up any trash.
![Page 25: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/25.jpg)
04/13/2023 25
Turning in Study ModelRemember to:
• Write the patient’s name and date of impression on both halves of the models.
• Turn model in with wax bite
• Turn in with self assessed competency/process paper
![Page 26: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/26.jpg)
04/13/2023 26
Final Criteria for a Acceptable Study Model
• All anatomy present• Free from voids and saliva nodules• Stone evenly mixed• Bases parallel ( 0-5 degrees) to the occlusal table• Symmetrical cuts and angles as described in the presentation• Have adequate depth of muccobuccal fold• Remain articulated when laid on all sides• Complete visual access of the dentition• Tongue area flat• Names and date on each half of the model
![Page 27: Study models 101 trimming](https://reader035.vdocuments.us/reader035/viewer/2022081504/55860ae5d8b42a8a638b4d20/html5/thumbnails/27.jpg)
04/13/2023 27