OPERATIVE- PROCEDURAL Flashcards
Clinical photo shown: Both 36, 37 have amalgam restorations
a. When to repair and restore? (7)
Repair:
- Repairing is restoring
Restore:
- To repair hard tissue damage/cavitation caused by the active, progressing caries/tooth-wear process (where non-operative prevention has failed repeatedly)
- To remove plaque stagnation areas within cavities/defects which will increase the risk of caries activity due to the lack of effective plaque removal by the patient
- To help to manage acute pulpitic pain caused by active caries by removing the bacterial biomass and
- sealing the defect, thereby protecting the pulp
- To restore the tooth to maintain structure and function in the dental arch
- Aesthetics.
Clinical photo shown: Both 36, 37 have amalgam restorations
b. Compare the cavity preparation requirements of amalgam and composite (4)
i. Amalgam:
Macro cavity modification using cavity undercuts, grooves, slots, flat surfaces.
Cavities with wider basses than orifices are required for retention of amalgam – undercuts
Slots/grooves help to prevent further displacement of the restoration
Flat cavity surfaces with rounded internal line angles help to improve the internal cavity support
Clinical photo shown: Both 36, 37 have amalgam restorations
b. Compare the cavity preparation requirements of amalgam and composite (4)
ii. Composite:
Micro cavity modification using enamel acid etch.
37% orthophosphoric acid removes smear layer, and selectively demineralizes prisms, creating micromechanical undercuts for resin retention
a. If your patient wants to replace the anterior restoration with DIRECT composite, what are the advantages and disadvantages of direct composite over cast restoration (8)
- Direct composite better than crowns
- Requires less tooth substance removal
- Lower cost
- Less likely to perforate pulpal
- Less likely to damage pulp
- May damage opposite tooth
- Crown better than direct composites
- More retention
- More resistance to fracture
- Less likely to dislodge
- Better aesthetics
a. Describe how to ensure good shade matching (5)
see page 152-153
b. Comment on the restorative procedure (2)
No rubber dam used so easier for bacterial contamination of the restorative surface and reduced bond strength
Wedge placed right next to the tooth restored rather than next to the adjacent tooth
Chief complaint: pain and gum swelling on the lower right region Dental history: 38 and 48 extracted 2 yrs ago
Pan and periapical of 47 are given: distal caries on both 37 and 47
a. Difficulties in restoration of 37D and 47D (10)
- Moisture control
- Saliva, blood bacterial contamination to cavity
- Failure in protecting restoration from moisture (cracking in GI)
- Indirect vision
- Incomplete caries removal, poor defined margin
- Inaccessibility
- Limited access of hand piece, instrument
- Difficult to achieve finger rest
- Deep caries close to pulp
- Risk in pulpal exposure
- Subgingival margin
- Risk of violation of biological width
- Iatrogenic trauma to soft tissue
- Mobile tooth
- Iatrogenic trauma
- Difficult to achieve finger rest
- Root fracture
- 37 deep amalgam MO restoration. Dull pain experienced after two weeks. Apical radiolucency
and widen PDL space. (Formative, 2011)
a. Suggest how to protect the pulp for the deep amalgam restoration (at least 4 ways) (4 marks)
Proper cavity preparation (undercut, round internal angle) to prevent tooth fracture and stress concentrated near pulp
GI lining or cavity varnish placed on wall close to pulp
Stepwise excavation to allow tertiary dentine formation
Apply Dycal (CaOH) when pulpal exposure caused by trauma during caries removal
Sufficient condensation force to prevent marginal leakage
Prevent high spot causing occlusal trauma
- Operative - Patient complains for pain/sensitivity initiated by hot and cold food and biting, pain goes off quickly. Found to have deep DO composite placed last week. (Formative, 2013)
a. What can be the cause of the problem (4)
Over-etching
Over drying
Bonding layer too thick
Marginal leakage due to polymerization shrinkage and improper incremental technique
High spot occlusion
Recurrent caries
Incomplete removal of previous caries
- Operative - Patient complains for pain/sensitivity initiated by hot and cold food and biting, pain goes off quickly. Found to have deep DO composite placed last week. (Formative, 2013)
b. If you have to replace the composite, how can you prevent the same problem (post-op sensitivity) (4)
Place GI lining in which wall closed to pulp
Sandwich technique (GI as base and composite build up)
Follow products instruction strictly, neither over etch nor over dry
Oblique incremental technique to reduce configuration factors
Avoid high spot occlusion
50 year old man. Clinical photo (anterior teeth apart front view), PAN, Study Cast.
C/O: reduced height of anterior tooth.
HPC: Sharp pain on cold drink. Not spontaneous.
I/O Photographs: showing generalized attrition and erosion of upper and lower arch. (mainly anterior) PAN
a. List the 3 dimension of colour and give the description. (6)
50 year old man. Clinical photo (anterior teeth apart front view), PAN, Study Cast.
C/O: reduced height of anterior tooth.
HPC: Sharp pain on cold drink. Not spontaneous.
I/O Photographs: showing generalized attrition and erosion of upper and lower arch. (mainly anterior) PAN
b. What precaution will you take when you select the shade for the patient? (3)
- Shade guide used should match the porcelain the technician is using
- Shade always be matched prior to tooth preparation
- Tooth become dehydrated and color changed
- Debris generated (enamel, metal, cement) can coat everything in the mouth
- Instruct patient to remove all distraction before shade matching (e.g. lipstick, earrings)
- Teeth need to be clean and unstained before matching
- Use of rubber cup and prophy paste to clean that region, ensure no paste remained
- Extra:
- Patient is seated in an upright position with mouth at operators’ eyes level
- Operators position between patient and light source
- Observation should be quick (less than 5 seconds, otherwise fatigue of retina) - Shade should be matched by value > chroma > hue in this order (except canine)
