GTR

Question 1

how to determine true perio regeneration

Answer 1

-histology (not practical)
-CAL gain
-PD reduction
-recession
-bone fill (radiographically or direct inspection)

Question 2

non-resorbable vs bioabsorbable barriers

Answer 2

Murphy and Gunsolley 2003: no difference

Question 3

GTR versus OFD for intrabony defects

Answer 3

Cortellini 1996:
-5.2mm gain in CAL vs. 2.3mm gain for OFD

OFD resulted in a higher risk for disease recurrence compared to regenerative procedures over a 20-year period

Question 4

GTR versus OFD for furcation defects

Answer 4

Murphy and Gunsolley: GTR> OFD
-improved CAL and PD, esp if GTR+bone

Question 5

GTR versus GTR+bone for intrabony defects

Answer 5

(Murphy and Gunsolley 2003):
-use of bone did not enhace regen

Question 6

EMD versus EMD+bone/membrane

Answer 6

Tu 2010 meta analysis:
-EMD+bone had 1mm more infrabony defect fill than EMD alone

Question 7

What is the grading system for CEPs

Answer 7

Masters, Hoskins 1964
Grade I: distinct change projecting towards the furcation,
Grade II: approaching the entrance but not in the furcation proper,
Grade III: extending into the furcation proper.

Question 8

prevalence of CEPs in mand and max teeth

Answer 8

Masters, Hoskins 1964
28% mandibular
17% maxillary

Question 9

How do CEPs affect periodontal treatment

Answer 9

-Enamel prevents attachment of the PDL fibers
- leads to a deep pocket and lower attachment and furcation involvement
-Susceptible to plaque accumulation and affects plaque removal
-Complicates SRP

Question 10

What is the width of the furcation entrance

Answer 10

Bower 1979
In 81% of the furcation of maxillary and mandibular molars the entrance was found to be 1.0mm or less and in 58% it was <0.75mm

Question 11

4 different cell types that can repopulate root surface after periodontal surgery

Answer 11

-epi, CT, bone, and PDL

Question 12

What are your goals for GTR?

Answer 12

-Increase in attachment
-Increase in bone
-Decrease in PD
-Minimal increase in recession
-Furcation closure!
-Tooth survival

Question 13

Can you have regeneration on root surfaces that previously harboured plaque?

Answer 13

-Gottlow 1984 proved that if you scaled roots, used a Millipore filter, you can get regeneration

Question 14

When do you decide to treat a defect with GTR?

Answer 14

-Cortellini and tonetti 2000: deeper defects (more than 3mm) benefit the most, getting superior CAL gains than shallower defects
-narrow defects <25 degrees had more attachment than >37 deg regenerative therapy

Question 15

*Which factors influence the success of periodontal regenerative therapy? (11 points)

Answer 15

DEFECT
1) # bony walls
2) depth of defect
3) width of defect
4) angle of defect

TOOTH
5) endo involvement
6) mobility

SURGERY
7) flap design
8) flap thickness
9) PASS principles

PATIENT
10) smoking
11) OH/SPT

Question 16

why do you remove sutures after 2 weeks

Answer 16

(Hiatt) flap doesnt reach functional integrity until 2 weeks post-surgery

Question 17

Bioexclusion

Answer 17

Using a barrier membrane to prevent epithelial migration, which then favors the repopulation of PDL cells and perivascular cells to differentiate into cementoblasts, fibroblasts, and osteoblasts, form the alveolar bone, PDL, and cementum

Question 18

• Is DFDBA superior to FDBA?

Answer 18

-DFDBA may potentially have osteoinductive properties as well due to BMPs
-Bowers et al: histologically verified true periodontal regeneration at intrabony defects using DFDBA
-Rummelhart 1989: no difference between FDBA and DFDBA
-2015 AAP consensus: concluded that DFDBA had the best body of evidence to support it as a predictable material for regeneration

Question 19

Does commercially available DFDBA contain enough active BMP?

Answer 19

it is unpredictable due to:
-donor age
-difference in processing and sterilization protocols
-particle size
-some is inactive

Question 20

Is there a high risk of disease transmission with allografts?

Answer 20

-Mellonig 1992: treatment of DFDBA successfully inactivates HIV

Question 21

What is the mechanism of action of EMDs?

Answer 21

EMD is a mixture of amelogenins which are involved in the formation of the periodontal apparatus during tooth development. By using EMD, they mimic the events that occur during tooth development and stimulate periodontal regeneration

EMD comes from piglet tooth buds

Question 22

Hamp Classification: (horizontal measurement)

Answer 22

F1: probe can penetrate furcation < 3mm
F2: probe >3mm but not through and through
F3: through and through furcation involvement

Question 23

Glickman Classification:

Answer 23

Grade 1: incipient suprabony lesion
Grade 2: loss of interradicular bone, but a portion remains intact
Grade 3: through and through (no bone attached at fornix); not clinically visible
Grade 4: through and through lesion; clinically visible; soft tissue has receded apically

Question 24

Tarnow and Fletcher classification: subclassification of Glickman: *measures VERTICAL probing depth from the roof of the furcation

Answer 24

A: 0-3mm
B: 4-6mm
C: >7mm

Question 25

how often do you get furcation closure in Grade II furcations with GTR

Answer 25

Bowers: Complete closure in 75%, remaining 70% are converted to Class I

Question 26

what are some bioactive agents used in regeneration

Answer 26

-rh-PDGF -EMD -PRP/PRF -BMP

Question 27

are biologics effective in tx intrabony defects

Answer 27

AAP Regeneartion workshop 2015 Kao: the use of EMD or rh-PDGF is effective in tx intrabony defects

Question 28

Regeneration for intrabony defects

Answer 28

AAP Consensus statement by Avila-Ortiz 2022 -combo therapies (bone+EMD or bone+barrier) are most effective -allografts and xenografts are ideal

Question 29

survival rate of GTR

Answer 29

Cortellini and Tonetti 96% after 8 years (89% for smokers and 100% for non-smokers)

Question 30

benefit of having biologic

Answer 30

-promotion and acceleration of healing and regeneration -reduced risk of postoperative complications -improved treatment outcomes -improved handling of bone -can be minimaly invasive and avoid large elevated flaps for membranes

Question 31

OFD versus GTR for furcations

Answer 31

Murphy and Gunsolley -GTR>OFD Chen: -GTR+bone was most effective for furcation closure

Question 33

factors that affect GTR for furcations

Answer 33

1) distance between the roof of furcation and crest of bone buccally and interproximally 2) roof of furcation and base of defect 3) depth of horizontal defect 4) root divergence should all be <4mm (Bowers 2003)

Question 34

does root conditioning improve outcomes for GTR

Answer 34

Mariotti- no difference in outcomes

Question 35

what do you expect for outcomes of GTR

Answer 35

5.2mm of CAL gain (Cortellini 1999) 95% defect closure for 3-wall defect and 80% defect closure for 2-wall defect (Cortellini)

Question 36

*what are your surgical steps for GTR after flap reflectioN/

Answer 36

1) flap reflection (MPPF, intrasulcular on B and L surfaces) 2) thorough SRP 3) inspect for any local factors or fractures (odontoplasty if needed) 4) EMD pref gel (24% EDTA for root conditioning) 5) add EMD to root 6) add bone graft mixed with EMD to bone defect 7) re-approximate flaps with vertical mattress sutures and ensure primary wound closure

Question 37

*what are important principles of regeneration?

Answer 37

PASS principles Primary closure Angiogenesis Space maintenance Wound stability

Question 38

* what is your post op instructions

Answer 38

1) antibiotics (amoxicillin) 2) analgesics (ibuprofen), also for swelling 3) chx mouth rinse 3) soft diet 4) avoid brushing area 5) 2 week post op

Question 39

*what are your perio diagnoses for palatal root groove with deep PD and slight swelling and suppuration and close to apex

Answer 39

1) local tooth related factors predisposing to periodontal diseases - palatal groove 2) periodontal abscess in a non-perio pt - alteration of root surface - minor anatomical alteration - developmental groove 3) endo-perio lesion with root damage - palatal groove

Question 40

how long should you wait to do GTR if you have an endo-perio lesion

Answer 40

should wait at least 3 months after endo to do the GTR

Question 41

*how to assess the outcome of your GTR surgery

Answer 41

1) cannot assess true regeneration unless it is looked at histologically 2) PD <=3mm 3) minimal to no recession 4) need CBCT to assess bone fill 5) no plaque or BOP