2. By.
Dr Ayesha Sadaf
(BDS gold medalist), FCPS(Pak),
Affiliate member of RCPS GLASGOW ,
Consultant prosthodontist SCFHS
Abutment tooth preparation
for RPD
3.
4. MOUTH PREPARATION FOR RPD
Pre Prosthetic Mouth
Preparation
Prosthetic Mouth preparation
5. “ Our objective should be the perpetual preservation of what remains
rather than the meticulous replacement of what is missing”
M . M. De Van
6. Pre prosthetic Mouth Preparation
ORAL SURGICAL PROCEDURES
CONDITIONING OF ABUSED AND IRRITATED TISSUES
Periodontal preparations &
Restorative procedures
Preparation of abutment tooth
7. Extraction of Hopeless teeth
1. Non restorable teeth
2. Poor prognosis teeth
3. Teeth which don’t contribute to
design of RPD
8. REMOVAL OF RESIDUAL ROOTS
1. Residual roots are close to tissue surface
2. R.R are in proximity to abutment teeth
3, Associated pathologies are evident
9. Conditioning of abused and irritated tissue
Denture stomatitis
Aetiology
1. Candida Albicans
PREDISPOSING FACTORS
• Poor denture hygiene
• Vit b 12 deficiency
• Trauma from denture
• Diabetes mellitus
• Immunocompromised patients
12. Acrylic denture can be immersed in sodium hypochlorite
solution daily.
Combination of mechanical and chemical method.
Denture half treated with
sodium hypo chloride for
20 minutes
19. Classification of abutment teeth
• Requiring minor modification to enamel of coronal portion
(Enameloplasty)
• Requiring modification to existing minor restoration
• Requiring major restorations i.e, full coverage crowns
20. Abutment tooth preparation
All proposed preparation should be done on the diagnostic cast
usually with the red pencil after initial surveying and designing
of RPD
21. Sequence of Abutment Tooth Preparation
• Establish Guide planes
• Modify un favorable survey lines
• Create favorable undercut areas
• Provide rest seats
30. Guiding Plane Dimensions *
Round
Axial Line
Angles
Round
Axial Line
Angles
2-4 mm
1/2-1/3
height
2-4 mm
1/2-1/3
height
8/14/2022 Dr. Aysha Sadaf 30
31. Guiding Plane Dimensions *
Use short guideplanes on Class I & II
Use long guideplanes on Class III & IV
Use short guideplanes on Class I & II
Use long guideplanes on Class III & IV
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40. CREATING UNDERCUT
ACID ETCH COMPOSITE IN THE GINGIVAL 1/3 CAN BE USED FOR
UNDERCUT CREATION
ULTRA FINE AND HYBRID COMPOSITES ARE MORE
SUITABLE
Notes de l'éditeur
PREVIOUSLY U HAVE STUDIED MOUTH PREPARATION FOR RPD, IT’S THE CONTINUATION OF IT, A RECALL
History of removable prosthesis goes back to 17th century ,when George Washington American president was given a set of partial denture made with ivory , gold and also his natural teeth. In th end he had one tooth remaining.
1.Preparation of mouth is fundamental for success of RPD
2. MOUTH preparation works under the philosophy of preservation of what remains
Preprosthetic mouth preparation follows the preliminary diagnosis and provisional treatment plan. Final treatment plan can be post poned until the desired outcome of moth preparation is achieved. Final impression can be delayed until all preprosthetic mouth preparation have achieved their objectives. Preprosthetic mouth preparation have been divide into four categories. 1. oral surgical procedures 2. conditioning of abused and irritated tissue 3 periodontal preparation 4. preparation of abutment teeth
Extractions are indicated on diagnostic cast with red pencil, tooth which are non-restorable and cannot be preserved are indicated for extraction before giving RPD
Denture stomatitis is diffuse inflammation of mucosa due to a fungal infection candida albicans.
REMOVAL OF CAUSATIVE FACTOR
IF THE PLAQUE CONTROL IS POOR DENTIST CAN DEMONSTRATE BY PLAQUE DISCLOSING SOLUTION.
EXPLAIN THE SIGNIFICANCE OF PLAQUE
DEMONSTRATE HOW TO REMOVE IT
trauma CAUSED BY OVEREXTENSIONS CAN BE REMOVED BY PRESSURE INDICATING PASTE OR SILICONE WASH IMPRESSION
LOSS OF OCCLUSAL CONTACTS OVER A LONG PERIOD OF TIME AND CAUSE TRAUMA TO DENTURE BEARING AREA.
OCCLUSAL ADJUSTMENT CAN BE DONE BY RECORDING NEW JAW RELATION AND PROVIDING OCCLUSAL CONTACTS
Temporary relining can be done with soft tissue conditioning materials. To soothe the irritated tissue for a short period of time
After surgery , periodontal treatment, endodontic treatment and tissue conditioning of the arch involved, the abutment teeth may be prepared tp provide support, stabilization, reciprocation and retention.
Two or more surface of the teeth which are parallel to one another and also to the path of insertion and removal
It is achieved by resisting forces which are acting on the denture other than the path of insertion
GUIDE PLANES HELP IN MAINTAINING THE CONTINUOUS. CONTACT OF THE reciprocating element with the tooth.
1. IS THE NORMAL POSITION OF CLASP DURING REMOVAL OF DENTURE. 2. WITHOUT GUIDE PLANES CLASP WILL CHANGE HIS POSITION IN OTHER DIRECTIONS AS THE PATIENTB WILL TILT OR ROTATE THE DENTURE
Guide surface permits an intimate contact with the surface of tooth creating a natural and more aesthetic appearance
All guide planes should be made parallel to the path of insertion and removal of denture.
Guiding planes should be at least 1/2 to 1/3 of the axial height of tooth (generally a minimum of 2 mm in height).
Lingual guiding planes for bracing or reciprocal arms should be 2-4 mm and ideally be located in the middle third of the crown, occluso-gingivally.
Guiding planes for distal-extension cases should be slightly shorter to avoid torquing of abutment teeth.
If occlusal rest seats are prepared initially, placement of a proximal guiding plane will remove some of the rest seat preparation, and result in a narrowed rest with a sharp occluso-proximal angle.
IF THE MAXIMUM HEIGHT of contour is located more occlusally then it causes deformation of clasp. A high clasp arm is more noticeable to patient and will interfere in masticatio
1. DEFORMATION OF CLASP, NOT GOIN INTO THE UNDERCUT 2. ROUNDING OFF SHARP ANGLES WILL ALTER THE SURVEY LINE
