Case: Fractured Resin Bonded Bridge in a 20Y Female
Treatment options :
- Another resin bonded bridge
- implant
- Denture
Conebeam CT:
- shows retained root in the edentulous space
Treatment:
- another all ceramic boned bridge
- took into account making a thicker connector to make sure it doesn’t fracture
- Cantilevered into the 11
Implants in young patients
- Rate of change in bone growth in adults changes, but never really stops, in a 20 year old these changes are more significant
Developmental changes
- Specifically in the anterior maxilla we get
- maxilla grows downward and forward
- Resorption of labial bone over maxillary anterior teeth
- Natural teeth also Extrude and upright
- examples from a implant case:
- infraocclusion
- blue coloring of labial gingiva
- collapse of labial soft tissue coverage
- recession exposing abutment
Koch etal 1996 - consensus conference on oral implants in young patients
3 ways to replace teeth
- no treatment
- space closure
- autotransplant
- Removable
- Implant
- bridgework - rBbs
Resin bonded bridges
- Treatment of choice in some situations
- lower incisors
- maxillary laterals
- occasionally other teeth with risk
- Posterior RBBs
- Low success
- aesthetic problem in mandible
- Assessment of tooth substrate
- Need enamel to bond and seal
- Materials
- Metal-ceramic (PFM)
- Need to choose an alloy that oxidizes, this allows for good bonding and a strong connector
- Etchable ceramic
- Non-etchable ceramic
- Metal-ceramic (PFM)
Metal-ceramic
Metal-ceramic alloy choices
The best choise is a non precious alloy
- What does this mean
- Ni-cr
- crco
Surface treatment
- Air abrade (sandblast) 50 um AI2O3 + ultrasonic
- roughens
- inc. SA
- cleans
- improves wetting
Resin cement = Panavia
- Silanted quartz
- Methacrylate resins (not BISGMA)
- MDP
- chemical bond via the metal oxide
Resultant metal-resin -enamel complex
- overall strong bond = 40 MPA
- No need to improve on resin-metal interface
- Need to improve TS of cement
- **this is the reason for tooth preparation want R+R to decrease tensile F on resin
- Components:
- tooth-tooth : cohesive
- tooth-resin : adhesive - weak
- resin-resin: cohesive - weakest, failure happens here **
- Resin - metal: adhesive - stronger high bond (2-3X tooth resin)
- Metal-metal: Cohesive
Bur
- Thin tapered fissure TC
- sharp = new
- will lose cutting ability after the autoclave
Provisional
- cavit grooves
- RPD/ Suspension bridge
Die Spacing
Case-selection
- Main
- maxillary laterals
- mIs
- occasionally other teeth (with risk)
- Diastemas?
- ??
Glass ceramics
- Silica based
- HF selectively dissolves glass
- Silane
- ETC
Abuzar, Locke, Burt, Clausen, Escobar ADJ 2018;63:279-