Treatment of teeth in partial edentulism - the choice between dentures, bridges and implants

Question 1

Survival of root-treated cantilevered conventional bridge

Answer 1

10 years

52%

Question 2

Survival of partial denture

Answer 2

10 years
50-69%
5 years
75%

Question 3

Survival of cantilevered conventional bridge (vital tooth)

Answer 3

10 years

80%

Question 4

Survival of average RBB

Answer 4

10 years

80%

Question 5

Survival of average post

Answer 5

10 years

80%

Question 6

Survival of tooth vitality after crowning

Answer 6

10 years

85% lose vitality

Question 7

Survival of fixed-fixed conventional bridge

Answer 7

10 years

89%

Question 8

Survival rate of PFM crown

Answer 8

10 years

96%

Question 9

Survival rate of implant

Answer 9

10 years

96%

Question 10

Survival rate of RCT-tooth

Answer 10

8 years: 97% (survival not success)

Question 11

RCT success

Answer 11

Existing sinus or PAP: reduces chances of success by around 50%
-further reduces by 14% for every 1mm of increasing size
Success lowered by 12% every mm short of the apex
Irrigating with CHX only reduces success chance by around 55%
Perforation “” by 60%
Long root filling “” by 67%
Achieving patency increases by 200%
Good coronal restoration increases by +1100%

Question 12

What are the main determining factors when choosing between the modalities?

Answer 12

Restorability of the teeth
Resistance and retention form for crowns (and therefore bridges)
Structural durability of the supporting structures
Perio support and perio health: huge factor here is pt’s involvement in own oral health
Cleansability and maintenance
Willingness for surgery and maintenance
Overall risk

Question 13

Structural durability of the supporting structures: Compromised support

Answer 13

Root-treated teeth more prone to # at cervical margin
Becomes more significant pontics
A post and core can also predispose to vertical root fracture

Question 14

Resistance and retention form for crowns (and therefore bridges) (4)

Answer 14

• resin cements help overcome problems but a ferrule is still considered to be critical
• a ferrule of at least 2-3mm is considered critical
• more importance on anterior teeth
• more important on the resisting surface in guidance (palatal of uppers)

Question 15

Inappropriate support will lead to > mobility and failure of rigid components or # of the abutments (3)

Answer 15

Debonding of a retainer
An uneven distribution of loading on the abutment teeth
ALSO abutment teeth are more prone to perio inflammation

Question 16

Ante’s law (3)

Answer 16

Shouldn’t use abutment teeth that have less root surface area that the teeth they’re replacing
Rubbish
-prospective and retrospective cohort studies have shown that abutment teeth with severely reduced but stable perio support compare favourably to teeth that aren’t perio compromised
-numerous studies confirm that pts require good perio care and occlusal control

Question 17

Does extraction and provision of denture expedite the loss of other/ more teeth (4)

Answer 17

Not necessarily, if well-maintained
Bergman (1982) showed that after being given OHI regularly, after 10yrs there were no differences to control groups in terms of perio outcome
However Wright (1992) showed that if just ‘given’ prostheses, 57% of those wearing a partial denture showed higher evidence of root caries
Preshaw Japson & Walls (2011)
-narrative review
-clear evidence that they can increase plaque and gingivitis
-increased risk of root caries
-no clear risk for periodontitis
-can possibly improve QoL

Question 18

Perio assessment is key (3)

Answer 18

Full perio assessment before tx plan confirmed
BPE, rads, pathology
Individually perio-involved teeth (active disease or advanced bony loss) may not be suitable for supporting crown and bridge work, or indeed a tooth-borne prosthesis

Question 19

Occlusal assessment

Answer 19

Clinical assessment of occlusal contacts, guidance patterns and whether any occlusal anomalies exist is really important
This will help you to determine risk of rehabilitating with crown and bridge work
Arguably least-well executed aspect of restoration planning

Question 20

Cleansability and maintenance (2)

Answer 20

Partial dentures are likely to cause root caries in absence of good OH
-also accumulate plaque and predispose to gingivitis - but not necessarily perio
Perio-implant mucositis and peri-implantitis are HUGE problems
-60% of pts will suffer peri-implant mucositis
-20% of pts will suffer from peri-implantitis
-for Pl, open flap debridement is only reliable intervention

Question 21

Consideration of retaining teeth as overdenture abutments - the holy grail? (5)

Answer 21

Proprioception
Improved stability/ retention
Maintain alveolar bone height
Psychological benefit
Increased biting force
Less mucosal coverage possible CoCr
****puts acrylic dentures at risk of fracture - put CoCr framework underneath to counter this

Question 22

Willigness for surgery (and associated timescales) (8)

Answer 22

Pts must understand how implant therapy works - in terms of planning and placement
Normally two surgeries
Often sedation is warranted
May require grafting from donor sites
Need for further surgery
Second stage surgery
Second stage surgery
THEN rehabilitation
Then maintenance

Question 23

Implant complications (4)

Answer 23

Bone loss >2mm over 5yrs - 5%
Screw or abutment loosening over 5yrs - 9%
Loss of retention over 5yrs 0 4%
Fracture of veneering material over 5yrs - 4%