complete dentures glossary

Question 1

adhesion

Answer 1

forces of attraction existing between dissimilar bodies in close contact i.e. mucosa and saliva molecules

Question 2

alginate

Answer 2

an impression material used in both primary and secondary impressinos

properties:

• cheap
• easy to use
• potentially messy
• elastic
• poor dimensional stability - altough for complete dentures its stability is fine

not accurate enough for crowns or bridges, but good for dentures

Question 3

buccan frenum

Answer 3

• fibrous band covered by mucous membrane
• attachment site for: levator anguli oris, orbicularis and buccinator
• requires greater clearance on buccal flange of denutre than labial frenum

Question 4

buccal shelf

Answer 4

• supporting structure on mandibular arch
• primary stress bearing area
• extends from the buccal frenum to the retro molar pad

Question 5

cohesion

Answer 5

attraction forces between similar bodies in close contact

Question 6

hamular notch

Answer 6

lies between the distal surface of the tuberosity and hamular process of medial pterygoid plate

Question 7

impression

Answer 7

reverse form of the tissues which is converted to a positive model using plaster or stone

Question 8

labial frenum

Answer 8

• fibrous band covered by mucous membrane
• extends from the labial aspect of the residual ridge to the lip
• a passive frenum and has no active muscle fibres
• V-shaped notch (labial notch) should be provided very carefully on the denture, which should be narrow but deep enough to avoid interference and should also seat adequately around frenum, if peripheral seal is to be achieved

Question 9

limiting structures

Answer 9

sites that will guide optimum extension of the denture to engage maximum surface area without encroaching upon muscle actions

encroaching upon these structure will lead t dislodgement of the denture and/or soreness of the area, while failure to cover the areas up to the limiting structre will imply decreased retention, stabiltiy and support

Question 10

mucobuccal fold

Answer 10

fold formed by the oral mucosa as it passes from the mandible or maxilla to the cheek

Question 11

mucostatic

Answer 11

where an impression is taken of compressible tissue at a resting state

Question 12

mylohyoid ridge

Answer 12

an area on the internal surface of the body of the mandible where the mylohyoid muscle attaches

this is a relief area - meaning that dentures should not bear load on this area

Question 13

PMMA

Answer 13

poly(methyl methacrylate)

acrylic

Question 14

relief areas

Answer 14

areas where there are either resorption under constant load, having fragule strucutres within or covered by thin mucosa which can be easily traumatised e.g. incisive papilla, palatine fovea, palatine raphe, creast of alveolar ridge, mylohyoid ridge, torus manidbularis and genial tubercle

dentures should be designed in such a way that the masticatory load is not concentrated over these areas

Question 15

retention

Answer 15

resistance to displacement of the denture base in vertical direction away from the tissues

Question 16

retromolar pad

Answer 16

triangular soft pad of tissue, posterior to edentulous ridfe

Question 17

special tray

Answer 17

an impression tray, custom made for a pt by a dental technician, ususally made from acrylic such as PMMA or shellac

Question 18

stability

Answer 18

resistance of denture to horizontal movement

Question 19

support

Answer 19

resistance to vertical movement of the denture towards the tissues

Question 20

supporting structures/stress bearing areas

Answer 20

supporting structures are load bearing areas

the denture should be designed such that most of the load is concentrated on these areas

Question 21

vibrating line

Answer 21

imaginary line from on hamular notch to the other which delineates the region where the soft palate starts moving when the pt says ‘ahh’

line between hard and soft palate