Cariology Flashcards
What pH can dentine dissolve?
6.7
Why does visual caries examination have low specifiticy
A number of dental conditions present clinically as changes in enamel colour/opacity/tecture/surface breakdwon
What is the main difference between ICDAS 5 and 6?
5 is less than half the tooth. 6 is more than half.
When would you do a prr over a fs?
When some cavitation has occured
What are the goals of sealants?
- Limit microbial adhesion and growth
- Optiise cleansibility
- Seal breached enamel
How does etching increase bonding? (4)
- Increases surface area
- Creates voids in rods, and opens dentine tubules which can be penetrated
- Increased surface energy
- Removal of debris
Why is a bevelled margin helpful for bonding?
Creates a more favourable orientation of the enamel rods
Increases surface area
Is dentine bonding chemical or micromechanical with composite?
Both. Penetration into dentine tubules + Collagen coupling with the OH group in HEMA component of resin.
Why is a primer needed?
Prevent collagen collapse
Dental amalgam is an alloy of:
- Mercury
- Silver
- Copper
- Tin
What are the categories of care on a tx plan.
A. STABILISATION
Primary - Emergency, Urgent
Secondary - Prevention, operative
B. REHABILITATION
C. MAINTENANCE AND MONITORING
how many mm of clean margin do you need before getting to affected dentine?
2-3mm
How long does it take to repair a porous white spot lesion with plaque control
2-3 weeks will become shiny and hard like normal enamel .
lesion underneath takes longer to repair.
What is the golden triangle of minimally invasive dentistry
- The histology of the dental substrate is being treated
- Consideration of the practical operative techniques available to excavate caries minimally
- The chemistry/handling of adhesive materials used
What causes cracked cusp symptoms to appear?
Fracture progression
When is cuspal overlay indicated (2)
- Less than 2mm width
- More than half the cusp is reduced
How much material is required for composite cuspal overlay?
2mm
How long should 37% etch stay on for?
30-60 seconds on enamel, 15 seconds on dentine
Notes on primer:
- Monomer which acts as intermediate between hydrophilic dentine and phobic adhesive
- Dentine not too dry, not too wet
- Apply and agitate 20 seconds
*
What is the role of adhesive?
Resin extension which forms a hybrid layer
How is the smear layer of dentine overcome?
Penetration with acidic monomer
What is the shear bond strength of freshly prepared enamel?
20MPa
What is the shear bond strength of freshly prepared dentine?
5-10MPa
What level of bleach is needed fro non vital bleaching
35%
2 reasons why non-vital teeth turn dark
- Trauma - internal bleeding
- Cements used in RCT
4 disadvantages of non-vital bleaching:
- Results not always predictable
- Risk of cervical root resorption
- Risk of soft tissue buns
- Reduce bond strength of enamel and dentine to composite resin
4 advantages of night guard vital bleaching:
- Easy application
- Safety
- Low cost
- Successful in greater than 90%
2 reasons why you should do non-aesthetic fillings before whitening:
- Sensitivity
- Hydrogen peroxide can reduce bond strength of composite resin
- During opening, the muscle pulls the disc forward
Lateral pterygoid muscle (inferior attachemd)
During closing, the muscle pulls the disc upward toward the slope of the joint
What muscles are involved in mouth opening
- Lateral pterygoid (inferior)
- Accessory
What muscles are involved in mouth closing
- Temporalis
- Masseter
- Medial pterygoid
- Lateral pterygoid (superior)
What are the implications of group function on restoration?
- Posterior restorations will be under more loading so increased likelihood of fracture.
- Tensile forces on composite as opposed to desired compressive force
A contact that displaces a tooth, diverting the mandible from its intended path. Usually caused by high restoration or cusp.
Premature contact
Any tooth contacts that interfere with or hinder harmonious mandibular movement is called
an Interference
Blue articulating paper should be used for:
Red should be used for:
- Blue for MI
- Red for excursive
How to do occlusion of fillings:
- Get patient to bite up and down on blue and adjust until does not feel high. Should be point contact on cusp tips.
- Get patient to chew on red paper, then bite up and down on blue.
- Any marks that are blue and red - keep
- Any marks that are red only - interferences - remove.
Name 6 tips to reduce potential loading on teeth
- Ensure axial loading
- Load closes to the fulcrum
- Flatten cusps
- Control excursive guidance
- Flatten occlusal planes
- Material selection
