Revision P.3 Flashcards
Posts & Cores
Post:
The post (dowel) is a metal or other rigid restorative material placed in the radicular(root) portion of a non vital tooth. A dowel traditionally made of metal is fitted in to a prepared canal of a natural tooth.
Posts & Cores
Core:
Refers to substructure , which replaces missing coronal structure and retains the final restoration .
- Dental posts should be recognized as simply a way to help to anchor a dental core in a tooth . If enough natural tooth structure exists that it can be relied upon to securely hold and retain the core, then no post is needed
Posts & Cores
How to decide which post is the ideal: Direct / Indirect (TIP)
It all comes down to the amount of ferrule present!
- 2-3mm ferrule (height) you are better off with an indirect cast post .
- ≥ 3-4mm ferrule you can then use a direct post
- For molar teeth its best to consider a Nayyar core instead of a post and core
Posts & Cores
What we have learned from the papers we read on Endodontically treated teeth
- The primary purpose of a post is to retain a core that can be used to retain the definitive prosthesis
- Sorensen and Martinoff reported that coronal coverage did not significantly improve the success of endodontically treated anterior teeth
- Posts do not reinforce endodontically treated teeth and are not necessary when substantial tooth structure is present
- 3-10% of post and core failures are attributable to root fractures
- The length of the post should ideally be 2/3 or 3⁄4 of the root canal
- The width of the post should not be more than 1/3 of the canal width
- There needs to be a minimum of 4-5mm apical GP
- Definitive prosthodontic treatment should be performed on asymptomatic endodontically treated teeth as soon as is practical after completing the endodontic therapy.
Steps for Taking a Shade:
- Take the Shade and Photographs at the Beginning of the Appointment. This Avoids Eye Fatigue & the teeth are not desiccated.
- Turn off the Dental Exam Light
- Use a Neutral Patient Towel (Blue or Gray, Never Yellow)
- Use Color Corrected Fluorescent Lights in Treatment Rooms.
- Set the Chair at 45 degrees and view the patient at eye level and at arms length.
- Be sure there are no shadows present.
- Position Shade Tab in the same Plane as the teeth.
- Squint eyes to use the cones of the eye. The cones are better for value and color than the rods that are being utilized more when you are not squinting.
- After 10 seconds, look at gray or blue before trying another Shade Tab.
Toothwear / Tooth Surface loss
Types of toothwear:
- Attrition
- Abrasion
- Erosion / Acid dissolution
- Abfraction
- Caries
- Iatrogenic
- Trauma
- Know the definitions for each type of toothwear
- Know their clinical features
Toothwear / Tooth Surface loss-How to manage such cases:
If you are planning on restoring the original shape of the teeth how would you plan it?
- Articulated study casts
- Wax-ups
Toothwear / Tooth Surface loss-How to manage such cases:
Why you would choose to have articulated waxed-up study models prior to you proceeding to any prosthesis preparations?
- Demonstrate to patient
- Used as a guide in order to know the extent of the preparation when for example preparing teeth for veneers
- Part of treatment planning, especially when complex treatment in order to view on the articulator
- When planning on increasing the OVD
Digital & Conventional Wax-ups
These are needed when:
- planning complex cases that would involve increase in OVD .
- Also necessary when treating veneer cases .
- Can also be useful to create putty indices when doing composite build- ups or when trying to close diastemas ]
Digital & Conventional Wax-ups
When would you ask the lab to make wax-ups for you?
- To demonstrate the final outcome to the patient and encourage them to undertake the treatment.
- To make provisionals / temporaries
- To create reduction indices
- To assess the size, shape, texture and teeth angulation
- To guide us in gingival contouring (When carrying out gingivecomy or crown lengthening
What is Immediate Dentine Sealing?
IDS is a universal concept whereby freshly cut dentine is sealed with an adhesive system immediately after preparation (before impression) for inlays / onlays / veneers and even crowns.
Which are the reasons for IDS?
- Bonding to freshly cut dentine
- Prepolymerisation thickness and stabilisation of the hybrid layer
- Selective wet dentin bonding
- Delayed loading of the dentine bond
- Decreased bacterial leakage
- Decreased sensitivity during provisional stage
- Decreased postoperative sensitivity
- Improved tooth preparation
- Reinforcement of remaining tooth structure
- Substitution of retention / resistance form
- Strengthening effect on crowns / onlays / veneers
- Facilitated try-in procedures and occlusal adjustments
- Compatibility of adhesive and luting cements
- Use of light-activated products always possible
- Spot bonding of temporaries
- Omission of provisional cements
- Optimal protection of direct pulp capping
- Sealing of endodontically treated teeth
- Two-stage placement of direct restorations
- Protection of root surfaces and biocorroded dentine
Understanding a Dental Implant?
There are two main categories of implants:
Tissue level Implants & Bone level implants
Understanding a Dental Implant?
Which are the main differences between the two types of Implants?
Osseointegration
Summary of Biological events:
Osseointegration
Primary vs secondary stability
Primary stability refers to the initial mechanical stability achieved at the time of implant placement, while secondary stability develops over time as a result of osseointegration. Both are important for the long-term success of an implant.
Primary stability is crucial because it allows for: Protection of the implant during the initial healing phase, Optimal bone-to-implant contact, Favorable conditions for osseointegration
While secondary stability is essential for the long-term success of the implant, it relies on the presence of adequate primary stability during the initial healing phase. Without sufficient primary stability, the implant may be at risk of micromotion, which can impair osseointegration and compromise the long-term stability and success of the implant.
Indications for implants
- Replace missing tooth / teeth
- Mandibular complete overdentures (where retention is a problem)
- Long spans – where bridges are not appropriate and the patient wants
- Trauma cases
- Oncology treated cases
- Poor tolerance of dentures (gag reflex / burning mouth)
- Orthodontic anchorage a fixed option
Contra-Indications for implants
- Too young (before full growth is completed)
- Large amounts of soft and hard tissue loss
- Psychological disturbances
- Active periodontal disease (increased risk of failed osseointegration and increased risk of perimplantitis)
- Smoking (more than 10 cigarettes daily can increase implant failure by 2.25x and 3.61x in patient who have implant placement with addition of bone)
- Bisphosphonates (IV higher risk than oral)
- Uncontrolled diabetes
- Active cancer therapy (radiotherapy and chemotherapy)
- Bruxist
ADVANTAGES OF DENTAL IMPLANTS
- Fixed replacement
- Good success / survival rates
- Preservation of tooth structure
- Provision of additional support
- Increased retention for removal prosthesis
- Resistance to caries
- Increased confidence
- Improves aesthetics, function and speech
So What is the Ideal Patient?
- Healthy adult patient whose growth has completed
- Hypodontia cases (congenitally missing)
- Anodontia cases
- Missing tooth or recently extracted and adjacent teeth are unrestored
- Periodontally stable
- Lost their tooth/teeth because of trauma
- Large edentulous spans and would only consider a fixed option
- Non smokers or smoking less than 10 cigarettes daily
- Motivated patient
- Financially can afford the treatment and any possible long-term maintenance costs
Implant Planning What information we need
Considering that the patient is fit and healthy and there are no contraindications for implants to be considered, we still need to have the following information:
- Adequate bone volume present (using the CBCT) – Height is more important than width as it is easier to augment.
- No Anatomical landmarks that may prevent ideal placement (nerves, roots, pathologies present)
- Adequate mesio-distal and bucco-lingual edentulous space . From the collar of the implant you would ideally need 1.5mm on either side . For example: For a 3.3mm implant you would ideally need 6.3mm mesio-distal space.
- Adequate Inter-occlusal space – There needs to be adequate interocclusal space based on the manufacturer recommendation – Usually it’s a minimum of 5mm for bone level implants and 7 for tissue level implants (both measurement from bone crest to opposing tooth)
- Check the condition of the adjacent teeth
- Make sure there is no active periodontal disease
- Make sure there is no Presence of any infection
Indications for dental photography?
- Keeping an accurate visual record of a patient’s history.
- Easier communication with the patient.
- Easier assessment of a prosthesis.
- Improvement of clinical skills.
- Correction of any mistakes.
- Legal protection.
- Shade selection.
- Marketing
Dental Photography
What equipment we need to have?
- Camera
- Lens
- Flash
- Mirrors & Retractors
Which settings should we set our cameras?
