Restorative materials used in paediatric dentition

Question 1

what restorative materials are used in paediatric dentistry?

Answer 1

• fissure sealants
• temporary and intermediate dressings (e.g. ZOE)
• glass ionomer
• resin modified glass ionomer
• compomer
• composite
• preformed metal crowns (PFMC)
• amalgam - banned for under 15s from July 2018

Question 2

what should the requirement for LA and the choice of restorative material be based on?

Answer 2

• caries extent
• longevity of tooth
• co-operation of the child

Question 3

what restorative material has the highest longesvity?

Answer 3

preformed metal crown (PFMC)

Question 4

what is the procedure of restoring cervical caries in a primary incisor/canine?

Answer 4

• hand excavate the caries or use a slow speed handpiece with a round bur
• wash and isolate - preferably with rubber dam but may not be possible
• restore with GIC or compomer or composite if good isolation

Question 5

what equipment is are used in the stainless steel crown technique?

Answer 5

• tapered diamond separating bur
• preformed metal crowns
• glass ionomer luting cement
• crown crimping pliers
• curved crown scissors

Question 5

what is the procedure of restoring interproximal caries in a primary incisor/canine?

Answer 5

• hand excavate or use slow speed round bur to remove caries
• wash and isolate - preferably with ribber dam
• place acetate strip into interproximal area and restore with compomer/composite

Question 6

how can you select the correct crown size?

Answer 6

• meaure mesio-distal width of crown or space with dividers
• trial and error after crown prep
• impression and crown prep on model

Question 7

how would you prep the crown for conventional PFMCs?

Answer 7

1. start from occlusal portion of marginal ridge
2. break contact area and produce knife edge finish mesially and distally - don’t damage adjacent teeth
3. ensure there are no ledges as they prevent crown from seating
4. reduce the occlusal surface by 1-2mm

Question 8

what causes rocking of a PFMC?

Answer 8

• if the cervical margin is greater than 1mm beyond the max. curvature, it is difficult to contour margins sufficiently to contact tooth throughout
• results in open margins and an unstable crown
• adjust the tooth preparation so that the crown is 0.5mm beyond maximum curvature

Question 9

what causes canting of the PFMC to one side?

Answer 9

• uneven reduction of the occlusal surface
• need to round the occluso-buccal line

Question 10

what causes a loss of space with PFMCs?

Answer 10

• with extensive caries, distal tooth can drift mesially due to physiological mesial drift resulting in loss of space for the crown on the affected tooth
• results in square shaped preparations and may use crowns for lowers on uppers

Question 11

what are separators? how do you place them?

Answer 11

**small rubber devices placed between teeth to create space for appliances
1. thread two lengths of dental floss though the separator
2. stretch tightly and floss through contact point
3. only need one half of separator between teeth
4. see patient 3-5 days later for removal

Question 11

what is the procedure of applying a Hall crown?

Answer 11

1. select correct crown size
2. dry the crown and fill with GI luting cement - no air bubbles
3. dry tooth if possible
4. place crown over tooth and partially seat until crown engages with contact points
5. remove finger and encourage child to bite into place or fully seat with firm finger pressure
6. remove extruding cement from margins ASAP (salt and vinegar taste can be upsetting)
7. ask child to bite down for 2-3 mins or hold crown firmly

Question 12

what are minor failures of the Hall crown technique?

Answer 12

• new/secondary caries
• crown may be worn, lost or requiring other intervention
• restoration lost but tooth is restorable
• reversible pulpitis treated without requiring pulpotomy or extraction

Question 13

what are major failures of the Hall crown technique?

Answer 13

• irreversible pulpitis
• abcess requiring pulpotomy or extraction
• interradicular radiolucency
• filling lost and tooth unrestorable

Question 14

what is shown here? what does it do?

Answer 14

space maintainer
* if primary molar cannot be restored and has to be taken out, you may want to maintain space for permanent tooth
* the tooth distal may drift mesially and there will be no space

Question 15

what is shown here?

Answer 15

distal shoe retainer