Quiz 4 - Spring Flashcards
Partial coverage retainers are just as retentive as full coverage retainers. True or False?
False, they are less retentive
Retainers with increased axial wall height are more retentive than retainers with decreased axial wall height. True or False?
True
Increased abutment taper increases the resistance and retention of the retainers. True or False?
False, it decreases it
Abutment taper is, of necessity, increased to align abutments and to allow a path of insertion. True or False?
True. This increased axial wall taper can create extra stresses on pulpal tissues.
The taper is less critical with longer teeth for bridges, true or false?
True
What are the three main types of fixed bridges?
- Pier to Pier
- Pier to Pier to Pier
- Cantilever
What is a pier to pier bridge?
Regular bridge – to abutements and pontic
What is a pier to pier to pier bridge?
3 abutements and 2 pontics
5 teeth are a minimum
What is a cantilever bridge?
1 pontic 1 Abutement Disadvantages - forces on the tooth. May increase – cantilever forces Use a cingulum/marginal ridge rest when possible
When doing a cantilever bridge, the pontic should be mesial or distal to the retainer?
The pontic should be mesial to the retainer. Apparently there is more force as you move distally.
Which teeth should you never use as abutments for cantilever bridges?
No lower or upper lateral incisors
From which tooth should you never go more distal with for a pontic with cantilever bridges?
No pontic distal to second premolars
Is it better to restore a bridge in CR or MI for the occlusion?
CR
Many people have anteriorly displaced discs, yet they are still functional for bridge use. True or False?
True. Disc will never be going back to what it was. Will never regain the correct position between the disc and fossa.
What are the characteristics of anteriorly displaced discs in TMJ?
Still will have to determine a reproducible and comfortable position to restore the teeth in that corresponds to their adaptive position the patient has developed do compensate for the displaced disc.
Disc will tend to regenerate well – adaptive joint.
Diagnosis - the mandible will shift – towards to the damaged side. If the LEFT disc is displaced anteriorly – locks the condyle in position – upon opening the right side will open more and the mandible will displace and sift towards the LEFT side
Conical and short roots have the same outlook as normal roots for abutment teeth. True or False?
False, they are not as good.
What is Ante’s Law?
The total periodontal membrane area of the abutment teeth must equal or exceed that of the teeth to be replaced. Or….
The total root surface area of the teeth to be replaced should not be greater than the total root surface area of the abutment teeth
What does the proprioception from the canines help with?
They help disengage the muscles and reduce excursive tooth wear. Premolars do not have proprioception like canines, we want more contact on incisors and canines.
What are the percentages for root surface area for a maxillary quadrant in accordance with Ante’s Law?
Central -10 Lateral - 9 Canine - 14 1st premolar - 12 2nd premolar - 11 1st molar - 22 2nd molar - 22
What are the percentages for root surface area for a mandibular quadrant in accordance with Ante’s Law?
Central -8 Lateral - 9 Canine - 15 1st premolar - 10 2nd premolar - 11 1st molar - 24 2nd molar - 23
What does a conical root do to crestal bone loss?
The conical shape of roots accelerates the negative impact of crestal bone loss, because conical shaped roots have more surface area toward the cervcical aspect of a tooth, and as you lose bone, you lose all that surface area first and all you have left is a skinny apex in bone with minimal surface area
What is the deflection of a fixed dental prosthesis proportional to? And what does that mean?
The cube of the length of its span
Other factors being equal, if a span of a single pontic is deflected a certain amount, a span of two similar pontics will move 8 times as much, and three will move 27 times as much. Deflection means how much it is flexed.
D = F X S^3, What do they stand for?
D = deflection F = force S = span
Excessive span length is a common contraindication for a fixed dental prosthesis. True or False?
True.
What can pier bridges do to end abutments? And what can help minimize this?
Pier abutments can become a fulcrum and loosen end abutments. A nonrigid connector (a key way) or a cantilever can help with this, so you don’t have this massive 5 unit pier bridge
Always, every tooth that is included in a fixed bridge increases the vulnerability of every other tooth that is a part of the same bridge. True or False?
True
What is the definition of a pontic?
An artificial tooth replacing a missing natural tooth that is designed to restore function and appearance
What are the five different types of pontics?
- Sanitary/Hygienic
- Saddle/Ridge-Lap
- Conical/Bullet
- Modified Ridge-Lap
- Ovate/Socketed
Sanitary/Hygienic:
Recommended Location = Advantages = Disadvantages = Indications = Contraindications = Materials =
Recommended Location = Posterior mandible
Advantages = Good access for oral hygiene
Disadvantages = Poor esthetics
Indications = Nonesthetic zones, impaired oral hygiene
Contraindications = Where esthetics is important, minimal vertical dimension
Materials = All metal
Large gap – with large enough space to actually pull out the debris.
Need 2-4 mm between the pontic and a eduntulous ridge
Clean out with waterPik or ProxaBrush (waterpik won’t scrape off plaque)
Saddle/Ridge-Lap:
Recommended Location = Advantages = Disadvantages = Indications = Contraindications = Materials =
Recommended Location = Not recommended Advantages = Esthetic Disadvantages = Not good for oral hygiene Indications = Not recommended Contraindications = Not recommended Materials = Not applicable
Conical/Bullet:
Recommended Location = Advantages = Disadvantages = Indications = Contraindications = Materials =
Recommended Location = Molars without esthetic requirements
Advantages = Good for oral hygiene
Disadvantages = Poor esthetics
Indications = Posterior areas where esthetics is of minimal concern
Contraindications = Poor oral hygiene
Materials = All-metal, metal-ceramic, all-resin
Modified Ridge-Lap”
Recommended Location = Advantages = Disadvantages = Indications = Contraindications = Materials =
Recommended Location = High esthetic requirement (anterior teeth and premolars, some maxillary molars)
Advantages = Good esthetics
Disadvantages = Moderately easy to clean
Indications = Most areas with esthetic concern
Contraindications = Where minimal esthetic concern exists
Materials = Metal-ceramic, all-ceramic, all-resin
Ovate/Socketed
Recommended Location = Advantages = Disadvantages = Indications = Contraindications = Materials =
Recommended Location = Very high esthetic requirement (maxillary incisors, canines, premolars)
Advantages = Superior esthetics, negligible food entrapment, ease of cleaning
Disadvantages = Requires surgical preparation, not for residual ridge defects
Indications = Desire for optimal esthetics, high smile line
Contraindications = Unwillingness for surgery, residual ridge defects
Materials = Metal-ceramic, all-ceramic, all-resin
The more metal you have in a bridge or pontic, the more strength you will always have. True or False?
True
It is smart to tell the lab to make the pontic tight, so there is no shadowing, and you can always adjust chairside. True or False?
True
Its ok if the tissue blanches first but then goes away
NOT OK if the blanching of tissue remains – may lead to tissue necrosis
It is fairly easy to grow bone height with bone grafts. True or False?
False
Line angles of pontics can be adjusted to create the illusion of either being smaller or larger. True or False?
True. Embrasure shape changes – give illusions to the teeth, helping define shapes.
Smaller = keep the facial line angles closer
Larger = expand the facial line angles
Although provisionals are helpful, they do not give a good idea to the patient of what the final prosthesis might look like. True or False?
False, they help a lot
What is the incisal index for bridges?
Given to the lab to help direct where to make the incisal edges of the crowns or bridges.
What is the smallest conventional implant width?
3.5 mm
How many mm’s of bone do you need between implants?
At least 2 mm
How many height do you need for one conventional implant?
WOULD NEED A TOTAL OF 7-8 MM of space for one implant
Mini implants may be a better solution for small areas like congenitally missing laterals. True or False?
True
What is the smallest small diameter implant width?
1.6 mm
How much height do you need for one small diameter implant?
5-6 mm
What are the five most common bridge failures?
- Fractured Porcelain
- ——May be able to polish
- ——If down to metal and visible - bond composite… might stay or not.
- ——If in porcelain still Etch with hydrofluoric acid – silanate- composite resin
- ——If on metal use a CB Metabond - Recurrent Caries
- Loosened Single Retainer
- Fractured Abutment
- Excessive Gap Formation Between Pontic(s) and the Edentulous Ridge, Especially in the Anterior Region
There will always be food traps with bridges and implants. True or False?
True
Embrasures will be a little larger with pontics than implants because the pontic is round shaped compared to the actual tooth shape. True or False?
False, Implants will have larger embrasures for those reasons.
What is the clinically and legally acceptable fewest teeth in a restored arch?
He gave some links, but they didn’t work
Molars and premolars are counted as two occlusal units when counting teeth. True or False?
False, just molars. Anterior teeth don’t affect occlusal unit counts
Many studies demonstrate that shortened dental arches comprising the anterior and premolar regions can meet the requirements of a functional dentition. Consequently, when priorities have to be set, restorative therapy should be aimed at preserving the most strategic parts of the dental arch: the anterior and premolar regions. This also implies that in cases of a shortened dental arch, the prompt replacement of absent posterior molars by free-end removable partial dentures leads to overtreatment and discomfort. True or False?
True
Complete absence of posterior support unilaterally or bilaterally appeared to increase the risk for developing signs and symptoms associated temporomandibular disorders. True or False?
True
What were the characteristics of extreme shortened dental arches consisting of just 0-2 pairs of functional premolars?
Extreme SDAs, comprising 0-2 pairs of occluding premolars, had significantly more interdental spacing, occlusal contact and vertical overlap of incisors compared to intermediate categories of SDAs.
Occlusal wear and tooth mobility were also highest in extreme SDAs.
It was concluded that the risk to occlusal instability seemed to occur in extreme SDAs comprising 0-2 occluding pairs of teeth whereas no such evidence was found for intermediate categories of SDAs.
What three aspects of ability/stability comprise adequate oral function?
- Chewing atability
- Occlusal stability
- Mandibular stability - TMJ
What are the characteristics of chewing ability?
Satisfactory chewing ability is perceived as long as the dental arch comprises an intact anterior region and 3-5 occluding pairs of teeth posteriorly.
Only small differences in chewing ability were found between subjects with these types of SDAs and subjects with complete dental arches.
What are the characteristics of occlusal stability?
SDAs comprising 3-4 occluding pairs of premolars posteriorly did not differ significantly from complete dental arches with regard to interdental spacing, occlusal tooth wear, vertical overbite and tooth mobility.
The risk to occlusal instability seemed to occur in extreme SDAs comprising 0-2 occluding pairs of teeth whereas no such evidence was found for intermediate categories of SDAs.
What are the characteristics of mandibular stability?
As long as premolar support is present bilaterally, signs and symptoms of temporomandibular disorders are unlikely to manifest themselves.
The increased risk was found only when all posterior support was unilaterally or bilaterally absent.
What are the six main contraindications to shortened dental arches?
- Marked dento-alveolar malrelationship - severe Angle Class II or Class III relationship
- Parafunction - intensive bruxism
- Pre-existing TMD
- Advanced pathological tooth wear
- Advanced periodontal disease - marked reduction in alveolar bone support
- Patient under the age of 40 years
What is the minimum number of occluding surfaces for a successful shortened dental arch?
4
Whether occluding units are spaced out or adjacent to one another, the efficiency remains the same. True or False?
False, they are more efficient when together.
There is no hard line of a minimum amount of teeth for function in a patient. True or False?
True.
No hard line of a minimum amount of teeth for function – it really depends on the patients.
But need to inform the patient that there will be more damage to the remaining teeth.
But just because a tooth is missing does not mean it needs to be replaced
What did the study on Up-to-15-Year Comparison of the Survival and Complication Burden of Three-Unit Tooth-Supported Fixed Dental Prostheses and Implant-Supported Single Crowns reveal?
The survival of three-unit tooth-supported fixed dental prostheses (TFDPs) and implant-supported single crowns (ISCs) over 15 years was not statistically different when replacing posterior teeth, but implant supported single crowns survived significantly better when replacing anterior teeth. The complication rates of the TFDPs and ISCs were similar, but the economic burden for the TFDPs was greater.
What did the study on Long-term clinical evaluation of 211 two-unit cantilevered resin-bonded fixed partial dentures reveal?
211 two-unit Resin-Bonded Fixed Partial Dentures (RBFPDs) were observed to have a success, retention and survival rate of 84.4, 86.7 and 90.0 percent, respectively, with a mean service life of 9.4 years.
Based on the clinical results, two-unit RBFPD are shown to be a durable prosthesis over the long term with high patient satisfaction. The posterior prostheses, particularly in the lower arch appeared to have a higher failure rate, and improved design features should be considered.
What did the study on Oral health-related quality of life in partially edentulous patients treated with removable, fixed, fixed-removable, and implant-supported prostheses reveal?
All treatments produced significant improvement in Oral Health Related Quality of Life (OHRQoL). The least amount of improvement was observed in patients with RDPs. OHRQoL changes in patients treated with FDPs and Implant-Supported Fixed Prostheses (ISFPs) were comparable. The same treatment can have different impacts on the OHRQoL of partially edentulous individuals depending on their age and Kennedy classification.
Patients who receive a prostheses at an older age have a harder time adjusting to them. True or False?
True
What is a Kennedy Class I?
Bilateral free-end, partially edentulous
What is a Kennedy Class II?
Unilateral free-end, partially edentulous
What is a Kennedy Class III?
Unilateral bounded, partially edentulous
What is a Kennedy Class IV?
Bilateral bounded partially edentulous
Once trimmed, the bite registration must not contact what to things?
- Soft tissue
2. Occluding surfaces of non-prepared teeth
What is the axial reduction at margin for posterior PFM’s?
Uniform 1.2-1.7 mm, 1.7 mostly at facial and 1.2 mm at lingual
What kind of involvement do anteriors, premolars, and molars have with biting?
Anteriors: Major
Premolars: None
Molars: None
What kind of involvement do anteriors, premolars, and molars have with chewing?
Anteriors: None
Premolars: Major
Molars: Major
What kind of involvement do anteriors, premolars, and molars have with speech?
Anteriors: Major
Premolars: None
Molars: None
What kind of involvement do anteriors, premolars, and molars have with esthetics?
Anteriors: Major
Premolars: Major
Molars: Minor
What kind of involvement do anteriors, premolars, and molars have with TMJ (Mandibular Stability)?
Anteriors: Major
Premolars: Major
Molars: Major
What kind of involvement do anteriors, premolars, and molars have with dental arch (occlusal stability)?
Anteriors: Major
Premolars: Major
Molars: Major
What kind of involvement do anteriors, premolars, and molars have with preservation of alveolar process?
Anteriors: Major
Premolars: Major
Molars: Major
What are the main six contraindications to SDA?
- Marked dento-alveolar malrelationship - severe Angle Class II and Class III relationship
- Parafunction - intensive bruxism
- Pre-existing TMD
- Advanced pathological tooth wear
- Advanced periodontal disease - marked
reduction in alveolar bone support - Patient under the age of 40 years
