Treatment of teeth in partial edentulism - the choice between dentures, bridges and implants Flashcards
Survival of root-treated cantilevered conventional bridge
10 years
52%
Survival of partial denture
10 years
50-69%
5 years
75%
Survival of cantilevered conventional bridge (vital tooth)
10 years
80%
Survival of average RBB
10 years
80%
Survival of average post
10 years
80%
Survival of tooth vitality after crowning
10 years
85% lose vitality
Survival of fixed-fixed conventional bridge
10 years
89%
Survival rate of PFM crown
10 years
96%
Survival rate of implant
10 years
96%
Survival rate of RCT-tooth
8 years: 97% (survival not success)
RCT success
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%
What are the main determining factors when choosing between the modalities?
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
Structural durability of the supporting structures: Compromised support
Root-treated teeth more prone to # at cervical margin
Becomes more significant pontics
A post and core can also predispose to vertical root fracture
Resistance and retention form for crowns (and therefore bridges) (4)
- 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)
Inappropriate support will lead to > mobility and failure of rigid components or # of the abutments (3)
Debonding of a retainer
An uneven distribution of loading on the abutment teeth
ALSO abutment teeth are more prone to perio inflammation
Ante’s law (3)
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
Does extraction and provision of denture expedite the loss of other/ more teeth (4)
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
Perio assessment is key (3)
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
Occlusal assessment
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
Cleansability and maintenance (2)
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
Consideration of retaining teeth as overdenture abutments - the holy grail? (5)
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
Willigness for surgery (and associated timescales) (8)
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
Implant complications (4)
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%
