Root resorption

Question 1

What is root resorption?

Answer 1

Non-bacterial destruction of the dental hard and soft tissues due to interaction of clastic cells.

Question 2

How does Root resorption occur?

Answer 2

Occurs via osteoclast activity but once there is no dentine, the dentinoclasts resorb the tooth.

Once the PDL is removed from the surface of the tooth, i.e. after bone resorption, the osteoclasts can gain access to the root.

Occurs via RANKL stimulation
- Parathyroid hormone.
- Bacterial lipopolysaccharide
- Trauma- avulsion, luxation and intrusion.

Question 3

What aspects of the tooth surface act to prevent root resorption?

Answer 3

Periodontal ligament

Cementum

Predentine

When these areas are damaged, the resorption can begin.

Question 4

What aspects of the clinical examination should be done?

Answer 4

Colour
Periodontal pocketing with a PCP12 probe both vertically and horizontally
Sinus including location in relation to muco-gingival junction
Swelling
Apical tenderness
Tenderness to percussion
Mobility
Occlusal contact in ICP and guidance
Integrity of adjacent teeth
Sensibility test

Question 5

What is internal inflammatory resorption (now known as internal infection related inflammatory root resorption)?

Answer 5

Coronal pulp is necrotic, loss of protective predentine makes the root surface susceptible to resorption by the bacteria.
- Infected material via the non-vital coronal part of the canal propagates the resorption.

Resorption starts at the root canal wall and progresses towards cementum.

Lesion includes inflammatory and vascular tissue- if perforated will communicate with PDL.

Apical pulp is vital

Lesion will continue to progress until apical pulp goes completely necrotic

Question 6

How does internal inflammatory resorption present clinically?

Answer 6

All appears normal clinically
- tooth may potentially be unrestorable.

No sinus, no swelling, no apical tenderness, normal mobility.

Positive response to sensibility

Question 7

How does internal inflammatory resorption present radiographically?

Answer 7

Symmetrical expansion of root canal walls (ballooning of canal)

Tramlines of root canal are indistinct but root surface is intact.

Usually no PA radiolucency.

Question 8

What is the treatment for internal inflammatory resorption?

Answer 8

Orthograde endodontics
- Instrumentation cannot deride resorption area but it facilitates irrigation with sodium hypochlorite.

Inter visit medicament- calcium hydroxide is caustic and can be used for chemical disinfection.
- for 4-6 weeks.

Thermal obturation.

Question 9

What is internal replacement resorption?

Answer 9

Pulp and dentine are replaced with bone.

Pulp appears radiopaque with trabecular pattern, that extends to the cementum.

Question 10

What is the treatment for internal replacement resorption?

Answer 10

No treatment.

RCT not possible- probably extract if it becomes symptomatic.

Question 11

What is external surface resorption?

Answer 11

Non microbial in origin, pulp is normal and vital.

Superficial resorption lacunae repaired with new cementum.

Orthodontics is usually the case of this type of resorption as teeth move through the bone, the roots are resorbed.

Question 12

What are the clinical and radiographic manifestations of external surface resorption?

Answer 12

Clinically- tooth may appear mobile, not TTP, positive for sensibility tests, no pocketing, no change in colour.

Radiographic- PDL intact, root appears shorter, trabecular pattern on root surface shows healing from previous surface resorption

Question 13

What are the potential causes of external surface resorption?

Answer 13

Ortho treatment
Ectopic teeth- pressure from the erupting tooth
Cysts
Idiopathic

Question 14

What is the treatment for external surface resorption?

Answer 14

OHI crucial in these patients- tooth loss due to perio is higher.

Splint if mobile.

Do not RCT- this will have no effect.

Question 15

What is external inflammatory resorption?

Answer 15

Inflammatory reaction, whereby the pulp is necrotic and there has been damage to the external surface of the root- potentially avulsion or luxation, which has caused a communication between root canal system and the peri-radicular tissues.

The bacteria that is now present within the per-radicular tissues initiates osteoclasts to resorb the bone and root surface.

Periodical inflammatory lesion precipitates the resorption process

Pulp drives resorptive process.

Question 16

How does external inflammatory resorption present clinically and radiographically?

Answer 16

Tooth is usually restored.
Previous trauma or injury to PDL.
Mobility may be increased
Negative to sensibility tests because the pulp is necrotic.

Radiographically
- restoration close to pulp horn
- External root resorption with a well defined radiopaque area associated with the resorption.
- Indistinct root surface, root canal tramlines intact.

Question 17

What is the treatment for external inflammatory resorption?

Answer 17

Remove the cause of the inflammation- usually endo treatment or extraction.

If there is lack of apical stop due to resorption- refer.

Question 18

What is external replacement resorption?

Answer 18

Cementum and dentine is replaced with bone- usually as a result of trauma to the tooth.
- If more than 20% of the PDL is damaged or lost, then then the bone cells are able to grow in contact with the root cells and the remaining fibroblasts able to recolonise the root surface.

Question 19

Clinically, how does external replacement resorption present?

Answer 19

Can be unrestored but infra-occluded.

Percussion note is high.

No PA radiolucency

No PDL on radiograph

Pulp is normal

Question 20

How does external replacement resorption (ankylosis related RR) present radiographically?

Answer 20

Loss of lamina dura
Loss of PDL space
External root substance has been resorbed and replaced with bone
Irregular root outline- ragged appearance

Question 21

What is the aetiology for external replacement resorption?

Answer 21

Trauma- significant injuries to the periodontium such that the bone is then in contact with external rot dentine to begin resorption.

Question 22

What is the treatment for external replacement resorption?

Answer 22

Must be monitored clinically and radiographically- warn the patient and prepare them for eventual loss of the tooth.
- has the patient stopped growing?

Can add composite incisally to mask the infra occlusion.

Important to consider if the patient is still growing because the tooth will not continue to develop and will start to impeded alveolar bone growth.
- Decoronation may be indicated to preserve bone volume.

Tooth then replaced with RBB or RPD.

Question 23

What is external cervical resorption?

Answer 23

Resorption around the cervical area of a tooth- commonly associated with ortho treatment, trauma, wind instruments, viral infection.

Question 24

What is the clinical presentation of external cervical resorption?

Answer 24

Periodontal pocketing may be present with BOP.
- +++ bleeding around cervicla margin.

Positive to sensibility tests
- pulp is fine.

Pink spit on cervical region.

Question 25

What are the radiographic findings of external cervical resorption?

Answer 25

Use parallax to view- indicated external surface.

Radiopaque lesion around the CEJ.

Usually spares the pulp- predentine protects the pulp.

Question 26

What is the treatment for external cervical resorption?

Answer 26

Monitor

Can decoronate

Extraction and prosthetic replacement

Internal repair and orthograde endodontics

Question 27

Why does external cervical resorption occur?

Answer 27

Caused by damage to the root surface in the cervical region of the tooth.

Initiated by propagation of either the infected root canal contents of the PDL microflora.