Lecture 1- Class intro and articulators Flashcards
what are the concerns about amalgam
-poor esthetics
- weakening of tooth from removal of tooth structure
-recurrent caries
-no adhesive bonding
-sensitivity of properties to manipulation
-brittle
-biocompatibility
-wastewater pollution
what are the advantages and disadvantages to composite
-advantages: aesthetics, bonding strengthens tooth struture, can be more conservative in tooth prep, less expensive than ceramic, reduced mercury
-disadvantages: composite shrinkage and secondary caries, durability, chipping of tooth, more skill and training required, need to keep working area dry, time and expense
what does bonding allow
the dentist to use dental composite to change shape, color, or contours
what is the oldest type of filling material available
gold foil
does gold foil last long
yes can last the lifetime of the patient
what materials can be used in crowns
- cast gold
- porcelain fused to metal
- high strength ceramics
what are issues with gold crowns
expensive and aesthetics
what is the success rates of PFM crowns
- 95% at 5-10 years
-97.5% at 7 years - 95.5% at 7 years
what are the options for tooth replacements
-complete dentures
-partial dentures
-fixed bridges and single teeth
what are the advantages to high strength ceramics
- broad range of indications
-excellent clinical performance
-accepted metal alternative
-less tooth reduction required - thinner coping thickness
-shaded coping options offer improved esthetics
what are articulators
a mechanical device that stimulates mandibular movements of condyles in their fossae
what are the uses of the articulator
-diagnosis
- treatment planning
-communicate with patients/patient education
-fabrication of prosthesis/restorations
what do non adjustable or hinge articulators do and what can they be used for
they allow for opening and closing movements
-can be used for single posterior restorations
what movements do semi-adjustable articulators do
-opening and closing
-excursive
-protrusive
what are the types of semi-adjustable articulators and where is the condyle located in each
-arcon: condyles in lower member, inclination in the upper member
-non arcon: condyles on upper member, inclination on the lower member
what type of articulator is ours
arcon
what is the purpose of the facebow
-orient the maxillary cast to the rotational axis in three planes
the face bow orients the dental cast in the same relationship to the ______ of the articulator
opening axis
what are the anatomic references in face bow
mandibular condyles, transverse horizontal axis and one other selected anterior point
what does the kinematic facebow locate
true transverse horizontal axis of rotation
what does the arbitrary facebow locate
the axis by using anatomical landmarks- utilizes average measurements to approximately locate the axis of rotation
what is the transverse horizontal axis ( or terminal hinge axis)
imaginary axis which passes through each of the mandibular condyles
-around this axis is where the pure rotational movement of the mandible occurs
where is the transverse horizontal axis located
about 8 mm under the soft tissues in front of the tragus
where is the bergstrom point
a point 10 mm anterior to the center of a spherical insert in the auditory meatus and 7 mm below the frankfort horizontal plane
where should the 3 points of reference be
two on each side of the face and one on the anterior face
what should the anterior reference point be
repeatable and reproducible
what can the 3rd points of reference be
-orbitale- lowest point on the infraorbital rim (spring bow)
- nasion (whip mix)
- maxillary incisor incisal edge (denar)
- lower edge of the nostril (older hanau models)
when do you use a facebow
-when cusp teeth are present
-interocclusal records are made at an increased occlusal vertical dimension
- the occlusal vertical dimension is subject to change and alteration in occlusal surfaces are necessary
